Provided by: perl-doc_5.40.0-8_all 
NAME
perlapi - autogenerated documentation for the perl public API
DESCRIPTION
This file contains most of the documentation of the perl public API, as generated by
embed.pl. Specifically, it is a listing of functions, macros, flags, and variables that
may be used by extension writers. Besides perlintern and config.h, some items are listed
here as being actually documented in another pod.
At the end is a list of functions which have yet to be documented. Patches welcome! The
interfaces of these are subject to change without notice.
Some of the functions documented here are consolidated so that a single entry serves for
multiple functions which all do basically the same thing, but have some slight
differences. For example, one form might process magic, while another doesn't. The name
of each variation is listed at the top of the single entry. But if all have the same
signature (arguments and return type) except for their names, only the usage for the base
form is shown. If any one of the forms has a different signature (such as returning
"const" or not) every function's signature is explicitly displayed.
Anything not listed here or in the other mentioned pods is not part of the public API, and
should not be used by extension writers at all. For these reasons, blindly using
functions listed in proto.h is to be avoided when writing extensions.
In Perl, unlike C, a string of characters may generally contain embedded "NUL" characters.
Sometimes in the documentation a Perl string is referred to as a "buffer" to distinguish
it from a C string, but sometimes they are both just referred to as strings.
Note that all Perl API global variables must be referenced with the "PL_" prefix. Again,
those not listed here are not to be used by extension writers, and may be changed or
removed without notice; same with macros. Some macros are provided for compatibility with
the older, unadorned names, but this support may be disabled in a future release.
Perl was originally written to handle US-ASCII only (that is characters whose ordinal
numbers are in the range 0 - 127). And documentation and comments may still use the term
ASCII, when sometimes in fact the entire range from 0 - 255 is meant.
The non-ASCII characters below 256 can have various meanings, depending on various things.
(See, most notably, perllocale.) But usually the whole range can be referred to as
ISO-8859-1. Often, the term "Latin-1" (or "Latin1") is used as an equivalent for
ISO-8859-1. But some people treat "Latin1" as referring just to the characters in the
range 128 through 255, or sometimes from 160 through 255. This documentation uses
"Latin1" and "Latin-1" to refer to all 256 characters.
Note that Perl can be compiled and run under either ASCII or EBCDIC (See perlebcdic).
Most of the documentation (and even comments in the code) ignore the EBCDIC possibility.
For almost all purposes the differences are transparent. As an example, under EBCDIC,
instead of UTF-8, UTF-EBCDIC is used to encode Unicode strings, and so whenever this
documentation refers to "utf8" (and variants of that name, including in function names),
it also (essentially transparently) means "UTF-EBCDIC". But the ordinals of characters
differ between ASCII, EBCDIC, and the UTF- encodings, and a string encoded in UTF-EBCDIC
may occupy a different number of bytes than in UTF-8.
The organization of this document is tentative and subject to change. Suggestions and
patches welcome perl5-porters@perl.org <mailto:perl5-porters@perl.org>.
The sections in this document currently are
"AV Handling"
"Callback Functions"
"Casting"
"Character case changing"
"Character classification"
"Compiler and Preprocessor information"
"Compiler directives"
"Compile-time scope hooks"
"Concurrency"
"COPs and Hint Hashes"
"Custom Operators"
"CV Handling"
"Debugging"
"Display functions"
"Embedding, Threads, and Interpreter Cloning"
"Errno"
"Exception Handling (simple) Macros"
"Filesystem configuration values"
"Floating point"
"General Configuration"
"Global Variables"
"GV Handling and Stashes"
"Hook manipulation"
"HV Handling"
"Input/Output"
"Integer"
"I/O Formats"
"Lexer interface"
"Locales"
"Magic"
"Memory Management"
"MRO"
"Multicall Functions"
"Numeric Functions"
"Optrees"
"Pack and Unpack"
"Pad Data Structures"
"Password and Group access"
"Paths to system commands"
"Prototype information"
"Reference-counted stack manipulation"
"REGEXP Functions"
"Reports and Formats"
"Signals"
"Site configuration"
"Sockets configuration values"
"Source Filters"
"Stack Manipulation Macros"
"String Handling"
"SV Flags"
"SV Handling"
"Tainting"
"Time"
"Typedef names"
"Unicode Support"
"Utility Functions"
"Versioning"
"Warning and Dieing"
"XS"
"Undocumented elements"
The listing below is alphabetical, case insensitive.
AV Handling
"AV"
Described in perlguts.
"AvALLOC"
Described in perlguts.
AvALLOC(AV* av)
"AvARRAY"
Returns a pointer to the AV's internal SV* array.
This is useful for doing pointer arithmetic on the array. If all you need is to look
up an array element, then prefer "av_fetch".
SV** AvARRAY(AV* av)
"av_clear"
Frees all the elements of an array, leaving it empty. The XS equivalent of "@array =
()". See also "av_undef".
Note that it is possible that the actions of a destructor called directly or
indirectly by freeing an element of the array could cause the reference count of the
array itself to be reduced (e.g. by deleting an entry in the symbol table). So it is a
possibility that the AV could have been freed (or even reallocated) on return from the
call unless you hold a reference to it.
void av_clear(AV *av)
"av_count"
Returns the number of elements in the array "av". This is the true length of the
array, including any undefined elements. It is always the same as
"av_top_index(av) + 1".
Size_t av_count(AV *av)
"av_create_and_push"
Push an SV onto the end of the array, creating the array if necessary. A small
internal helper function to remove a commonly duplicated idiom.
NOTE: "av_create_and_push" must be explicitly called as "Perl_av_create_and_push" with
an "aTHX_" parameter.
void Perl_av_create_and_push(pTHX_ AV ** const avp,
SV * const val)
"av_create_and_unshift_one"
Unshifts an SV onto the beginning of the array, creating the array if necessary. A
small internal helper function to remove a commonly duplicated idiom.
NOTE: "av_create_and_unshift_one" must be explicitly called as
"Perl_av_create_and_unshift_one" with an "aTHX_" parameter.
SV ** Perl_av_create_and_unshift_one(pTHX_ AV ** const avp,
SV * const val)
"av_delete"
Deletes the element indexed by "key" from the array, makes the element mortal, and
returns it. If "flags" equals "G_DISCARD", the element is freed and NULL is returned.
NULL is also returned if "key" is out of range.
Perl equivalent: "splice(@myarray, $key, 1, undef)" (with the "splice" in void context
if "G_DISCARD" is present).
SV * av_delete(AV *av, SSize_t key, I32 flags)
"av_exists"
Returns true if the element indexed by "key" has been initialized.
This relies on the fact that uninitialized array elements are set to "NULL".
Perl equivalent: exists($myarray[$key]).
bool av_exists(AV *av, SSize_t key)
"av_extend"
Pre-extend an array so that it is capable of storing values at indexes "0..key". Thus
"av_extend(av,99)" guarantees that the array can store 100 elements, i.e. that
"av_store(av, 0, sv)" through "av_store(av, 99, sv)" on a plain array will work
without any further memory allocation.
If the av argument is a tied array then will call the "EXTEND" tied array method with
an argument of "(key+1)".
void av_extend(AV *av, SSize_t key)
"av_fetch"
Returns the SV at the specified index in the array. The "key" is the index. If
"lval" is true, you are guaranteed to get a real SV back (in case it wasn't real
before), which you can then modify. Check that the return value is non-NULL before
dereferencing it to a "SV*".
See "Understanding the Magic of Tied Hashes and Arrays" in perlguts for more
information on how to use this function on tied arrays.
The rough perl equivalent is $myarray[$key].
SV ** av_fetch(AV *av, SSize_t key, I32 lval)
"AvFILL"
Same as "av_top_index" or "av_tindex".
SSize_t AvFILL(AV* av)
"av_fill"
Set the highest index in the array to the given number, equivalent to Perl's
"$#array = $fill;".
The number of elements in the array will be "fill + 1" after av_fill() returns. If
the array was previously shorter, then the additional elements appended are set to
NULL. If the array was longer, then the excess elements are freed. "av_fill(av, -1)"
is the same as av_clear(av).
void av_fill(AV *av, SSize_t fill)
"av_len"
Same as "av_top_index". Note that, unlike what the name implies, it returns the
maximum index in the array. This is unlike "sv_len", which returns what you would
expect.
To get the true number of elements in the array, instead use "av_count".
SSize_t av_len(AV *av)
"av_make"
Creates a new AV and populates it with a list (**strp, length "size") of SVs. A copy
is made of each SV, so their refcounts are not changed. The new AV will have a
reference count of 1.
Perl equivalent: "my @new_array = ($scalar1, $scalar2, $scalar3...);"
AV * av_make(SSize_t size, SV **strp)
"av_pop"
Removes one SV from the end of the array, reducing its size by one and returning the
SV (transferring control of one reference count) to the caller. Returns &PL_sv_undef
if the array is empty.
Perl equivalent: "pop(@myarray);"
SV * av_pop(AV *av)
"av_push"
Pushes an SV (transferring control of one reference count) onto the end of the array.
The array will grow automatically to accommodate the addition.
Perl equivalent: "push @myarray, $val;".
void av_push(AV *av, SV *val)
"av_push_simple"
This is a cut-down version of av_push that assumes that the array is very
straightforward - no magic, not readonly, and AvREAL - and that "key" is not less than
-1. This function MUST NOT be used in situations where any of those assumptions may
not hold.
Pushes an SV (transferring control of one reference count) onto the end of the array.
The array will grow automatically to accommodate the addition.
Perl equivalent: "push @myarray, $val;".
void av_push_simple(AV *av, SV *val)
"av_shift"
Removes one SV from the start of the array, reducing its size by one and returning the
SV (transferring control of one reference count) to the caller. Returns &PL_sv_undef
if the array is empty.
Perl equivalent: "shift(@myarray);"
SV * av_shift(AV *av)
"av_store"
Stores an SV in an array. The array index is specified as "key". The return value
will be "NULL" if the operation failed or if the value did not need to be actually
stored within the array (as in the case of tied arrays). Otherwise, it can be
dereferenced to get the "SV*" that was stored there (= "val")).
Note that the caller is responsible for suitably incrementing the reference count of
"val" before the call, and decrementing it if the function returned "NULL".
Approximate Perl equivalent: "splice(@myarray, $key, 1, $val)".
See "Understanding the Magic of Tied Hashes and Arrays" in perlguts for more
information on how to use this function on tied arrays.
SV ** av_store(AV *av, SSize_t key, SV *val)
"av_tindex"
"av_top_index"
These behave identically. If the array "av" is empty, these return -1; otherwise they
return the maximum value of the indices of all the array elements which are currently
defined in "av".
They process 'get' magic.
The Perl equivalent for these is $#av.
Use "av_count" to get the number of elements in an array.
SSize_t av_tindex(AV *av)
"av_undef"
Undefines the array. The XS equivalent of undef(@array).
As well as freeing all the elements of the array (like av_clear()), this also frees
the memory used by the av to store its list of scalars.
See "av_clear" for a note about the array possibly being invalid on return.
void av_undef(AV *av)
"av_unshift"
Unshift the given number of "undef" values onto the beginning of the array. The array
will grow automatically to accommodate the addition.
Perl equivalent: "unshift @myarray, ((undef) x $num);"
void av_unshift(AV *av, SSize_t num)
"get_av"
Returns the AV of the specified Perl global or package array with the given name (so
it won't work on lexical variables). "flags" are passed to "gv_fetchpv". If "GV_ADD"
is set and the Perl variable does not exist then it will be created. If "flags" is
zero (ignoring "SVf_UTF8") and the variable does not exist then "NULL" is returned.
Perl equivalent: "@{"$name"}".
NOTE: the perl_get_av() form is deprecated.
AV * get_av(const char *name, I32 flags)
"newAV"
"newAV_mortal"
"newAV_alloc_x"
"newAV_alloc_xz"
These all create a new AV, setting the reference count to 1. If you also know the
initial elements of the array with, see ""av_make"".
As background, an array consists of three things:
1. A data structure containing information about the array as a whole, such as its
size and reference count.
2. A C language array of pointers to the individual elements. These are treated as
pointers to SVs, so all must be castable to SV*.
3. The individual elements themselves. These could be, for instance, SVs and/or AVs
and/or HVs, etc.
An empty array need only have the first data structure, and all these functions create
that. They differ in what else they do, as follows:
"newAV" form
This does nothing beyond creating the whole-array data structure. The Perl
equivalent is approximately "my @array;"
This is useful when the minimum size of the array could be zero (perhaps there are
likely code paths that will entirely skip using it).
If the array does get used, the pointers data structure will need to be allocated
at that time. This will end up being done by "av_extend">, either explicitly:
av_extend(av, len);
or implicitly when the first element is stored:
(void)av_store(av, 0, sv);
Unused array elements are typically initialized by "av_extend".
"newAV_mortal" form
This also creates the whole-array data structure, but also mortalises it. (That
is to say, a reference to the AV is added to the "temps" stack.)
"newAV_alloc_x" form
This effectively does a "newAV" followed by also allocating (uninitialized) space
for the pointers array. This is used when you know ahead of time the likely
minimum size of the array. It is more efficient to do this than doing a plain
"newAV" followed by an "av_extend".
Of course the array can be extended later should it become necessary.
"size" must be at least 1.
"newAV_alloc_xz" form
This is "newAV_alloc_x", but initializes each pointer in it to NULL. This gives
added safety to guard against them being read before being set.
"size" must be at least 1.
The following examples all result in an array that can fit four elements (indexes 0 ..
3):
AV *av = newAV();
av_extend(av, 3);
AV *av = newAV_alloc_x(4);
AV *av = newAV_alloc_xz(4);
In contrast, the following examples allocate an array that is only guaranteed to fit
one element without extending:
AV *av = newAV_alloc_x(1);
AV *av = newAV_alloc_xz(1);
AV * newAV ()
AV * newAV_mortal ()
AV * newAV_alloc_x (SSize_t size)
AV * newAV_alloc_xz(SSize_t size)
"newAVav"
Creates a new AV and populates it with values copied from an existing AV. The new AV
will have a reference count of 1, and will contain newly created SVs copied from the
original SV. The original source will remain unchanged.
Perl equivalent: "my @new_array = @existing_array;"
AV * newAVav(AV *oav)
"newAVhv"
Creates a new AV and populates it with keys and values copied from an existing HV.
The new AV will have a reference count of 1, and will contain newly created SVs copied
from the original HV. The original source will remain unchanged.
Perl equivalent: "my @new_array = %existing_hash;"
AV * newAVhv(HV *ohv)
"Nullav"
"DEPRECATED!" It is planned to remove "Nullav" from a future release of Perl. Do not
use it for new code; remove it from existing code.
Null AV pointer.
(deprecated - use "(AV *)NULL" instead)
Callback Functions
"call_argv"
Performs a callback to the specified named and package-scoped Perl subroutine with
"argv" (a "NULL"-terminated array of strings) as arguments. See perlcall.
Approximate Perl equivalent: "&{"$sub_name"}(@$argv)".
NOTE: the perl_call_argv() form is deprecated.
SSize_t call_argv(const char *sub_name, I32 flags, char **argv)
"call_method"
Performs a callback to the specified Perl method. The blessed object must be on the
stack. See perlcall.
NOTE: the perl_call_method() form is deprecated.
SSize_t call_method(const char *methname, I32 flags)
"call_pv"
Performs a callback to the specified Perl sub. See perlcall.
NOTE: the perl_call_pv() form is deprecated.
SSize_t call_pv(const char *sub_name, I32 flags)
"call_sv"
Performs a callback to the Perl sub specified by the SV.
If neither the "G_METHOD" nor "G_METHOD_NAMED" flag is supplied, the SV may be any of
a CV, a GV, a reference to a CV, a reference to a GV or SvPV(sv) will be used as the
name of the sub to call.
If the "G_METHOD" flag is supplied, the SV may be a reference to a CV or SvPV(sv) will
be used as the name of the method to call.
If the "G_METHOD_NAMED" flag is supplied, SvPV(sv) will be used as the name of the
method to call.
Some other values are treated specially for internal use and should not be depended
on.
See perlcall.
NOTE: the perl_call_sv() form is deprecated.
SSize_t call_sv(SV *sv, I32 flags)
"DESTRUCTORFUNC_NOCONTEXT_t"
Described in perlguts.
"DESTRUCTORFUNC_t"
Described in perlguts.
"ENTER"
Opening bracket on a callback. See "LEAVE" and perlcall.
ENTER;
"ENTER_with_name"
Same as "ENTER", but when debugging is enabled it also associates the given literal
string with the new scope.
ENTER_with_name("name");
"eval_pv"
Tells Perl to "eval" the given string in scalar context and return an SV* result.
NOTE: the perl_eval_pv() form is deprecated.
SV * eval_pv(const char *p, I32 croak_on_error)
"eval_sv"
Tells Perl to "eval" the string in the SV. It supports the same flags as "call_sv",
with the obvious exception of "G_EVAL". See perlcall.
The "G_RETHROW" flag can be used if you only need eval_sv() to execute code specified
by a string, but not catch any errors.
By default the code is compiled and executed with the default hints, such as strict
and features. Set "G_USEHINTS" in flags to use the current hints from "PL_curcop".
NOTE: the perl_eval_sv() form is deprecated.
SSize_t eval_sv(SV *sv, I32 flags)
"FREETMPS"
Closing bracket for temporaries on a callback. See "SAVETMPS" and perlcall.
FREETMPS;
"G_DISCARD"
Described in perlcall.
"G_EVAL"
Described in perlcall.
"GIMME"
"DEPRECATED!" It is planned to remove "GIMME" from a future release of Perl. Do not
use it for new code; remove it from existing code.
A backward-compatible version of "GIMME_V" which can only return "G_SCALAR" or
"G_LIST"; in a void context, it returns "G_SCALAR". Deprecated. Use "GIMME_V"
instead.
U32 GIMME
"GIMME_V"
The XSUB-writer's equivalent to Perl's "wantarray". Returns "G_VOID", "G_SCALAR" or
"G_LIST" for void, scalar or list context, respectively. See perlcall for a usage
example.
U32 GIMME_V
"G_KEEPERR"
Described in perlcall.
"G_LIST"
Described in perlcall.
"G_NOARGS"
Described in perlcall.
"G_SCALAR"
Described in perlcall.
"G_VOID"
Described in perlcall.
"is_lvalue_sub"
Returns non-zero if the sub calling this function is being called in an lvalue
context. Returns 0 otherwise.
I32 is_lvalue_sub()
"LEAVE"
Closing bracket on a callback. See "ENTER" and perlcall.
LEAVE;
"LEAVE_with_name"
Same as "LEAVE", but when debugging is enabled it first checks that the scope has the
given name. "name" must be a literal string.
LEAVE_with_name("name");
"MORTALDESTRUCTOR_SV"
Described in perlguts.
MORTALDESTRUCTOR_SV(SV *coderef, SV *args)
"mortal_destructor_sv"
This function arranges for either a Perl code reference, or a C function reference to
be called at the end of the current statement.
The "coderef" argument determines the type of function that will be called. If it is
SvROK() it is assumed to be a reference to a CV and will arrange for the coderef to be
called. If it is not SvROK() then it is assumed to be a SvIV() which is SvIOK() whose
value is a pointer to a C function of type "DESTRUCTORFUNC_t" created using PTR2INT().
Either way the "args" parameter will be provided to the callback as a parameter,
although the rules for doing so differ between the Perl and C mode. Normally this
function is only used directly for the Perl case and the wrapper mortal_destructor_x()
is used for the C function case.
When operating in Perl callback mode the "args" parameter may be NULL in which case
the code reference is called with no arguments, otherwise if it is an AV (SvTYPE(args)
== SVt_PVAV) then the contents of the AV will be used as the arguments to the code
reference, and if it is any other type then the "args" SV will be provided as a single
argument to the code reference.
When operating in a C callback mode the "args" parameter will be passed directly to
the C function as a "void *" pointer. No additional processing of the argument will be
peformed, and it is the callers responsibility to free the "args" parameter if
necessary.
Be aware that there is a signficant difference in timing between the end of the
current statement and the end of the current pseudo block. If you are looking for a
mechanism to trigger a function at the end of the current pseudo block you should look
at ""SAVEDESTRUCTOR_X"" in perlapi instead of this function.
void mortal_destructor_sv(SV *coderef, SV *args)
"MORTALSVFUNC_X"
Described in perlguts.
MORTALSVFUNC_X(SVFUNC_t f, SV *sv)
"PL_errgv"
Described in perlcall.
"save_aelem"
"save_aelem_flags"
These each arrange for the value of the array element "av[idx]" to be restored at the
end of the enclosing pseudo-block.
In "save_aelem", the SV at C**sptr> will be replaced by a new "undef" scalar. That
scalar will inherit any magic from the original **sptr, and any 'set' magic will be
processed.
In "save_aelem_flags", "SAVEf_KEEPOLDELEM" being set in "flags" causes the function to
forgo all that: the scalar at **sptr is untouched. If "SAVEf_KEEPOLDELEM" is not
set, the SV at C**sptr> will be replaced by a new "undef" scalar. That scalar will
inherit any magic from the original **sptr. Any 'set' magic will be processed if and
only if "SAVEf_SETMAGIC" is set in in "flags".
void save_aelem (AV *av, SSize_t idx, SV **sptr)
void save_aelem_flags(AV *av, SSize_t idx, SV **sptr,
const U32 flags)
"save_aptr"
Described in perlguts.
void save_aptr(AV **aptr)
"save_ary"
Described in perlguts.
AV * save_ary(GV *gv)
"SAVEBOOL"
Described in perlguts.
SAVEBOOL(bool i)
"SAVEDELETE"
Described in perlguts.
SAVEDELETE(HV * hv, char * key, I32 length)
"SAVEDESTRUCTOR"
Described in perlguts.
SAVEDESTRUCTOR(DESTRUCTORFUNC_NOCONTEXT_t f, void *p)
"SAVEDESTRUCTOR_X"
Described in perlguts.
SAVEDESTRUCTOR_X(DESTRUCTORFUNC_t f, void *p)
"SAVEFREEOP"
Described in perlguts.
SAVEFREEOP(OP *op)
"SAVEFREEPV"
Described in perlguts.
SAVEFREEPV(char *pv)
"SAVEFREERCPV"
Described in perlguts.
SAVEFREERCPV(char *pv)
"SAVEFREESV"
Described in perlguts.
SAVEFREESV(SV* sv)
"SAVEGENERICSV"
Described in perlguts.
SAVEGENERICSV(char **psv)
"save_hash"
Described in perlguts.
HV * save_hash(GV *gv)
"save_helem"
"save_helem_flags"
These each arrange for the value of the hash element (in Perlish terms) "$hv{key}]" to
be restored at the end of the enclosing pseudo-block.
In "save_helem", the SV at C**sptr> will be replaced by a new "undef" scalar. That
scalar will inherit any magic from the original **sptr, and any 'set' magic will be
processed.
In "save_helem_flags", "SAVEf_KEEPOLDELEM" being set in "flags" causes the function to
forgo all that: the scalar at **sptr is untouched. If "SAVEf_KEEPOLDELEM" is not
set, the SV at C**sptr> will be replaced by a new "undef" scalar. That scalar will
inherit any magic from the original **sptr. Any 'set' magic will be processed if and
only if "SAVEf_SETMAGIC" is set in in "flags".
void save_helem (HV *hv, SV *key, SV **sptr)
void save_helem_flags(HV *hv, SV *key, SV **sptr,
const U32 flags)
"save_hptr"
Described in perlguts.
void save_hptr(HV **hptr)
"SAVEINT"
Described in perlguts.
SAVEINT(int i)
"save_item"
Described in perlguts.
void save_item(SV *item)
"SAVEIV"
Described in perlguts.
SAVEIV(IV i)
"SAVEI8"
Described in perlguts.
SAVEI8(I8 i)
"SAVEI16"
Described in perlguts.
SAVEI16(I16 i)
"SAVEI32"
Described in perlguts.
SAVEI32(I32 i)
"SAVELONG"
Described in perlguts.
SAVELONG(long i)
"SAVEMORTALIZESV"
Described in perlguts.
SAVEMORTALIZESV(SV* sv)
"SAVEPPTR"
Described in perlguts.
SAVEPPTR(char * p)
"SAVERCPV"
Described in perlguts.
SAVERCPV(char *pv)
"save_scalar"
Described in perlguts.
SV * save_scalar(GV *gv)
"SAVESPTR"
Described in perlguts.
SAVESPTR(SV * s)
"SAVESTACK_POS"
Described in perlguts.
SAVESTACK_POS()
"SAVESTRLEN"
Described in perlguts.
SAVESTRLEN(STRLEN i)
"save_svref"
Described in perlguts.
SV * save_svref(SV **sptr)
"SAVETMPS"
Opening bracket for temporaries on a callback. See "FREETMPS" and perlcall.
SAVETMPS;
Casting
"Atof"
This is a synonym for ""my_atof"".
NV Atof(NN const char * const s)
"cBOOL"
Cast-to-bool. When Perl was able to be compiled on pre-C99 compilers, a "(bool)" cast
didn't necessarily do the right thing, so this macro was created (and made somewhat
complicated to work around bugs in old compilers). Now, many years later, and C99 is
used, this is no longer required, but is kept for backwards compatibility.
bool cBOOL(bool expr)
"INT2PTR"
Described in perlguts.
type INT2PTR(type, int value)
"I_V"
Cast an NV to IV while avoiding undefined C behavior
IV I_V(NV what)
"I_32"
Cast an NV to I32 while avoiding undefined C behavior
I32 I_32(NV what)
"PTR2IV"
Described in perlguts.
IV PTR2IV(void * ptr)
"PTR2nat"
Described in perlguts.
IV PTR2nat(void *)
"PTR2NV"
Described in perlguts.
NV PTR2NV(void * ptr)
"PTR2ul"
Described in perlguts.
unsigned long PTR2ul(void *)
"PTR2UV"
Described in perlguts.
UV PTR2UV(void * ptr)
"PTRV"
Described in perlguts.
"U_V"
Cast an NV to UV while avoiding undefined C behavior
UV U_V(NV what)
"U_32"
Cast an NV to U32 while avoiding undefined C behavior
U32 U_32(NV what)
Character case changing
Perl uses "full" Unicode case mappings. This means that converting a single character to
another case may result in a sequence of more than one character. For example, the
uppercase of "ß" (LATIN SMALL LETTER SHARP S) is the two character sequence "SS". This
presents some complications The lowercase of all characters in the range 0..255 is a
single character, and thus "toLOWER_L1" is furnished. But, "toUPPER_L1" can't exist, as
it couldn't return a valid result for all legal inputs. Instead "toUPPER_uvchr" has an
API that does allow every possible legal result to be returned.) Likewise no other
function that is crippled by not being able to give the correct results for the full range
of possible inputs has been implemented here.
"toFOLD"
"toFOLD_A"
"toFOLD_utf8"
"toFOLD_utf8_safe"
"toFOLD_uvchr"
These all return the foldcase of a character. "foldcase" is an internal case for "/i"
pattern matching. If the foldcase of character A and the foldcase of character B are
the same, they match caselessly; otherwise they don't.
The differences in the forms are what domain they operate on, and whether the input is
specified as a code point (those forms with a "cp" parameter) or as a UTF-8 string
(the others). In the latter case, the code point to use is the first one in the
buffer of UTF-8 encoded code points, delineated by the arguments "p .. e - 1".
"toFOLD" and "toFOLD_A" are synonyms of each other. They return the foldcase of any
ASCII-range code point. In this range, the foldcase is identical to the lowercase.
All other inputs are returned unchanged. Since these are macros, the input type may
be any integral one, and the output will occupy the same number of bits as the input.
There is no "toFOLD_L1" nor "toFOLD_LATIN1" as the foldcase of some code points in the
0..255 range is above that range or consists of multiple characters. Instead use
"toFOLD_uvchr".
"toFOLD_uvchr" returns the foldcase of any Unicode code point. The return value is
identical to that of "toFOLD_A" for input code points in the ASCII range. The
foldcase of the vast majority of Unicode code points is the same as the code point
itself. For these, and for code points above the legal Unicode maximum, this returns
the input code point unchanged. It additionally stores the UTF-8 of the result into
the buffer beginning at "s", and its length in bytes into *lenp. The caller must have
made "s" large enough to contain at least "UTF8_MAXBYTES_CASE+1" bytes to avoid
possible overflow.
NOTE: the foldcase of a code point may be more than one code point. The return value
of this function is only the first of these. The entire foldcase is returned in "s".
To determine if the result is more than a single code point, you can do something like
this:
uc = toFOLD_uvchr(cp, s, &len);
if (len > UTF8SKIP(s)) { is multiple code points }
else { is a single code point }
"toFOLD_utf8" and "toFOLD_utf8_safe" are synonyms of each other. The only difference
between these and "toFOLD_uvchr" is that the source for these is encoded in UTF-8,
instead of being a code point. It is passed as a buffer starting at "p", with "e"
pointing to one byte beyond its end. The "p" buffer may certainly contain more than
one code point; but only the first one (up through "e - 1") is examined. If the UTF-8
for the input character is malformed in some way, the program may croak, or the
function may return the REPLACEMENT CHARACTER, at the discretion of the
implementation, and subject to change in future releases.
UV toFOLD (UV cp)
UV toFOLD_A (UV cp)
UV toFOLD_utf8 (U8* p, U8* e, U8* s, STRLEN* lenp)
UV toFOLD_utf8_safe(U8* p, U8* e, U8* s, STRLEN* lenp)
UV toFOLD_uvchr (UV cp, U8* s, STRLEN* lenp)
"toLOWER"
"toLOWER_A"
"toLOWER_LATIN1"
"toLOWER_LC"
"toLOWER_L1"
"toLOWER_utf8"
"toLOWER_utf8_safe"
"toLOWER_uvchr"
These all return the lowercase of a character. The differences are what domain they
operate on, and whether the input is specified as a code point (those forms with a
"cp" parameter) or as a UTF-8 string (the others). In the latter case, the code point
to use is the first one in the buffer of UTF-8 encoded code points, delineated by the
arguments "p .. e - 1".
"toLOWER" and "toLOWER_A" are synonyms of each other. They return the lowercase of
any uppercase ASCII-range code point. All other inputs are returned unchanged. Since
these are macros, the input type may be any integral one, and the output will occupy
the same number of bits as the input.
"toLOWER_L1" and "toLOWER_LATIN1" are synonyms of each other. They behave identically
as "toLOWER" for ASCII-range input. But additionally will return the lowercase of any
uppercase code point in the entire 0..255 range, assuming a Latin-1 encoding (or the
EBCDIC equivalent on such platforms).
"toLOWER_LC" returns the lowercase of the input code point according to the rules of
the current POSIX locale. Input code points outside the range 0..255 are returned
unchanged.
"toLOWER_uvchr" returns the lowercase of any Unicode code point. The return value is
identical to that of "toLOWER_L1" for input code points in the 0..255 range. The
lowercase of the vast majority of Unicode code points is the same as the code point
itself. For these, and for code points above the legal Unicode maximum, this returns
the input code point unchanged. It additionally stores the UTF-8 of the result into
the buffer beginning at "s", and its length in bytes into *lenp. The caller must have
made "s" large enough to contain at least "UTF8_MAXBYTES_CASE+1" bytes to avoid
possible overflow.
NOTE: the lowercase of a code point may be more than one code point. The return value
of this function is only the first of these. The entire lowercase is returned in "s".
To determine if the result is more than a single code point, you can do something like
this:
uc = toLOWER_uvchr(cp, s, &len);
if (len > UTF8SKIP(s)) { is multiple code points }
else { is a single code point }
"toLOWER_utf8" and "toLOWER_utf8_safe" are synonyms of each other. The only
difference between these and "toLOWER_uvchr" is that the source for these is encoded
in UTF-8, instead of being a code point. It is passed as a buffer starting at "p",
with "e" pointing to one byte beyond its end. The "p" buffer may certainly contain
more than one code point; but only the first one (up through "e - 1") is examined. If
the UTF-8 for the input character is malformed in some way, the program may croak, or
the function may return the REPLACEMENT CHARACTER, at the discretion of the
implementation, and subject to change in future releases.
UV toLOWER (UV cp)
UV toLOWER_A (UV cp)
UV toLOWER_LATIN1 (UV cp)
UV toLOWER_LC (UV cp)
UV toLOWER_L1 (UV cp)
UV toLOWER_utf8 (U8* p, U8* e, U8* s, STRLEN* lenp)
UV toLOWER_utf8_safe(U8* p, U8* e, U8* s, STRLEN* lenp)
UV toLOWER_uvchr (UV cp, U8* s, STRLEN* lenp)
"toTITLE"
"toTITLE_A"
"toTITLE_utf8"
"toTITLE_utf8_safe"
"toTITLE_uvchr"
These all return the titlecase of a character. The differences are what domain they
operate on, and whether the input is specified as a code point (those forms with a
"cp" parameter) or as a UTF-8 string (the others). In the latter case, the code point
to use is the first one in the buffer of UTF-8 encoded code points, delineated by the
arguments "p .. e - 1".
"toTITLE" and "toTITLE_A" are synonyms of each other. They return the titlecase of
any lowercase ASCII-range code point. In this range, the titlecase is identical to
the uppercase. All other inputs are returned unchanged. Since these are macros, the
input type may be any integral one, and the output will occupy the same number of bits
as the input.
There is no "toTITLE_L1" nor "toTITLE_LATIN1" as the titlecase of some code points in
the 0..255 range is above that range or consists of multiple characters. Instead use
"toTITLE_uvchr".
"toTITLE_uvchr" returns the titlecase of any Unicode code point. The return value is
identical to that of "toTITLE_A" for input code points in the ASCII range. The
titlecase of the vast majority of Unicode code points is the same as the code point
itself. For these, and for code points above the legal Unicode maximum, this returns
the input code point unchanged. It additionally stores the UTF-8 of the result into
the buffer beginning at "s", and its length in bytes into *lenp. The caller must have
made "s" large enough to contain at least "UTF8_MAXBYTES_CASE+1" bytes to avoid
possible overflow.
NOTE: the titlecase of a code point may be more than one code point. The return value
of this function is only the first of these. The entire titlecase is returned in "s".
To determine if the result is more than a single code point, you can do something like
this:
uc = toTITLE_uvchr(cp, s, &len);
if (len > UTF8SKIP(s)) { is multiple code points }
else { is a single code point }
"toTITLE_utf8" and "toTITLE_utf8_safe" are synonyms of each other. The only
difference between these and "toTITLE_uvchr" is that the source for these is encoded
in UTF-8, instead of being a code point. It is passed as a buffer starting at "p",
with "e" pointing to one byte beyond its end. The "p" buffer may certainly contain
more than one code point; but only the first one (up through "e - 1") is examined. If
the UTF-8 for the input character is malformed in some way, the program may croak, or
the function may return the REPLACEMENT CHARACTER, at the discretion of the
implementation, and subject to change in future releases.
UV toTITLE (UV cp)
UV toTITLE_A (UV cp)
UV toTITLE_utf8 (U8* p, U8* e, U8* s, STRLEN* lenp)
UV toTITLE_utf8_safe(U8* p, U8* e, U8* s, STRLEN* lenp)
UV toTITLE_uvchr (UV cp, U8* s, STRLEN* lenp)
"toUPPER"
"toUPPER_A"
"toUPPER_utf8"
"toUPPER_utf8_safe"
"toUPPER_uvchr"
These all return the uppercase of a character. The differences are what domain they
operate on, and whether the input is specified as a code point (those forms with a
"cp" parameter) or as a UTF-8 string (the others). In the latter case, the code point
to use is the first one in the buffer of UTF-8 encoded code points, delineated by the
arguments "p .. e - 1".
"toUPPER" and "toUPPER_A" are synonyms of each other. They return the uppercase of
any lowercase ASCII-range code point. All other inputs are returned unchanged. Since
these are macros, the input type may be any integral one, and the output will occupy
the same number of bits as the input.
There is no "toUPPER_L1" nor "toUPPER_LATIN1" as the uppercase of some code points in
the 0..255 range is above that range or consists of multiple characters. Instead use
"toUPPER_uvchr".
"toUPPER_uvchr" returns the uppercase of any Unicode code point. The return value is
identical to that of "toUPPER_A" for input code points in the ASCII range. The
uppercase of the vast majority of Unicode code points is the same as the code point
itself. For these, and for code points above the legal Unicode maximum, this returns
the input code point unchanged. It additionally stores the UTF-8 of the result into
the buffer beginning at "s", and its length in bytes into *lenp. The caller must have
made "s" large enough to contain at least "UTF8_MAXBYTES_CASE+1" bytes to avoid
possible overflow.
NOTE: the uppercase of a code point may be more than one code point. The return value
of this function is only the first of these. The entire uppercase is returned in "s".
To determine if the result is more than a single code point, you can do something like
this:
uc = toUPPER_uvchr(cp, s, &len);
if (len > UTF8SKIP(s)) { is multiple code points }
else { is a single code point }
"toUPPER_utf8" and "toUPPER_utf8_safe" are synonyms of each other. The only
difference between these and "toUPPER_uvchr" is that the source for these is encoded
in UTF-8, instead of being a code point. It is passed as a buffer starting at "p",
with "e" pointing to one byte beyond its end. The "p" buffer may certainly contain
more than one code point; but only the first one (up through "e - 1") is examined. If
the UTF-8 for the input character is malformed in some way, the program may croak, or
the function may return the REPLACEMENT CHARACTER, at the discretion of the
implementation, and subject to change in future releases.
UV toUPPER (UV cp)
UV toUPPER_A (UV cp)
UV toUPPER_utf8 (U8* p, U8* e, U8* s, STRLEN* lenp)
UV toUPPER_utf8_safe(U8* p, U8* e, U8* s, STRLEN* lenp)
UV toUPPER_uvchr (UV cp, U8* s, STRLEN* lenp)
Character classification
This section is about functions (really macros) that classify characters into types, such
as punctuation versus alphabetic, etc. Most of these are analogous to regular expression
character classes. (See "POSIX Character Classes" in perlrecharclass.) There are several
variants for each class. (Not all macros have all variants; each item below lists the
ones valid for it.) None are affected by "use bytes", and only the ones with "LC" in the
name are affected by the current locale.
The base function, e.g., isALPHA(), takes any signed or unsigned value, treating it as a
code point, and returns a boolean as to whether or not the character represented by it is
(or on non-ASCII platforms, corresponds to) an ASCII character in the named class based on
platform, Unicode, and Perl rules. If the input is a number that doesn't fit in an octet,
FALSE is returned.
Variant "isFOO_A" (e.g., isALPHA_A()) is identical to the base function with no suffix
"_A". This variant is used to emphasize by its name that only ASCII-range characters can
return TRUE.
Variant "isFOO_L1" imposes the Latin-1 (or EBCDIC equivalent) character set onto the
platform. That is, the code points that are ASCII are unaffected, since ASCII is a subset
of Latin-1. But the non-ASCII code points are treated as if they are Latin-1 characters.
For example, isWORDCHAR_L1() will return true when called with the code point 0xDF, which
is a word character in both ASCII and EBCDIC (though it represents different characters in
each). If the input is a number that doesn't fit in an octet, FALSE is returned. (Perl's
documentation uses a colloquial definition of Latin-1, to include all code points below
256.)
Variant "isFOO_uvchr" is exactly like the "isFOO_L1" variant, for inputs below 256, but if
the code point is larger than 255, Unicode rules are used to determine if it is in the
character class. For example, isWORDCHAR_uvchr(0x100) returns TRUE, since 0x100 is LATIN
CAPITAL LETTER A WITH MACRON in Unicode, and is a word character.
Variants "isFOO_utf8" and "isFOO_utf8_safe" are like "isFOO_uvchr", but are used for UTF-8
encoded strings. The two forms are different names for the same thing. Each call to one
of these classifies the first character of the string starting at "p". The second
parameter, "e", points to anywhere in the string beyond the first character, up to one
byte past the end of the entire string. Although both variants are identical, the suffix
"_safe" in one name emphasizes that it will not attempt to read beyond "e - 1", provided
that the constraint "s < e" is true (this is asserted for in "-DDEBUGGING" builds). If
the UTF-8 for the input character is malformed in some way, the program may croak, or the
function may return FALSE, at the discretion of the implementation, and subject to change
in future releases.
Variant "isFOO_LC" is like the "isFOO_A" and "isFOO_L1" variants, but the result is based
on the current locale, which is what "LC" in the name stands for. If Perl can determine
that the current locale is a UTF-8 locale, it uses the published Unicode rules; otherwise,
it uses the C library function that gives the named classification. For example,
isDIGIT_LC() when not in a UTF-8 locale returns the result of calling isdigit(). FALSE is
always returned if the input won't fit into an octet. On some platforms where the C
library function is known to be defective, Perl changes its result to follow the POSIX
standard's rules.
Variant "isFOO_LC_uvchr" acts exactly like "isFOO_LC" for inputs less than 256, but for
larger ones it returns the Unicode classification of the code point.
Variants "isFOO_LC_utf8" and "isFOO_LC_utf8_safe" are like "isFOO_LC_uvchr", but are used
for UTF-8 encoded strings. The two forms are different names for the same thing. Each
call to one of these classifies the first character of the string starting at "p". The
second parameter, "e", points to anywhere in the string beyond the first character, up to
one byte past the end of the entire string. Although both variants are identical, the
suffix "_safe" in one name emphasizes that it will not attempt to read beyond "e - 1",
provided that the constraint "s < e" is true (this is asserted for in "-DDEBUGGING"
builds). If the UTF-8 for the input character is malformed in some way, the program may
croak, or the function may return FALSE, at the discretion of the implementation, and
subject to change in future releases.
"isALNUM"
"isALNUM_A"
"isALNUM_LC"
"isALNUM_LC_uvchr"
These are each a synonym for their respectively named ""isWORDCHAR"" variant.
They are provided for backward compatibility, even though a word character includes
more than the standard C language meaning of alphanumeric. To get the C language
definition, use the corresponding ""isALPHANUMERIC"" variant.
bool isALNUM(UV ch)
"isALNUMC"
"isALNUMC_A"
"isALNUMC_LC"
"isALNUMC_LC_uvchr"
"isALNUMC_L1"
These are discouraged, backward compatibility macros for ""isALPHANUMERIC"". That is,
each returns a boolean indicating whether the specified character is one of
"[A-Za-z0-9]", analogous to "m/[[:alnum:]]/".
The "C" suffix in the names was meant to indicate that they correspond to the C
language isalnum(3).
bool isALNUMC(UV ch)
"isALPHA"
"isALPHA_A"
"isALPHA_LC"
"isALPHA_LC_utf8_safe"
"isALPHA_LC_uvchr"
"isALPHA_L1"
"isALPHA_utf8"
"isALPHA_utf8_safe"
"isALPHA_uvchr"
Returns a boolean indicating whether the specified input is one of "[A-Za-z]",
analogous to "m/[[:alpha:]]/". See the top of this section for an explanation of the
variants.
bool isALPHA (UV ch)
bool isALPHA_A (UV ch)
bool isALPHA_LC (UV ch)
bool isALPHA_LC_utf8_safe(U8 * s, U8 *end)
bool isALPHA_LC_uvchr (UV ch)
bool isALPHA_L1 (UV ch)
bool isALPHA_utf8 (U8 * s, U8 * end)
bool isALPHA_utf8_safe (U8 * s, U8 * end)
bool isALPHA_uvchr (UV ch)
"isALPHANUMERIC"
"isALPHANUMERIC_A"
"isALPHANUMERIC_LC"
"isALPHANUMERIC_LC_utf8_safe"
"isALPHANUMERIC_LC_uvchr"
"isALPHANUMERIC_L1"
"isALPHANUMERIC_utf8"
"isALPHANUMERIC_utf8_safe"
"isALPHANUMERIC_uvchr"
Returns a boolean indicating whether the specified character is one of "[A-Za-z0-9]",
analogous to "m/[[:alnum:]]/". See the top of this section for an explanation of the
variants.
bool isALPHANUMERIC (UV ch)
bool isALPHANUMERIC_A (UV ch)
bool isALPHANUMERIC_LC (UV ch)
bool isALPHANUMERIC_LC_utf8_safe(U8 * s, U8 *end)
bool isALPHANUMERIC_LC_uvchr (UV ch)
bool isALPHANUMERIC_L1 (UV ch)
bool isALPHANUMERIC_utf8 (U8 * s, U8 * end)
bool isALPHANUMERIC_utf8_safe (U8 * s, U8 * end)
bool isALPHANUMERIC_uvchr (UV ch)
"isASCII"
"isASCII_A"
"isASCII_LC"
"isASCII_LC_utf8_safe"
"isASCII_LC_uvchr"
"isASCII_L1"
"isASCII_utf8"
"isASCII_utf8_safe"
"isASCII_uvchr"
Returns a boolean indicating whether the specified character is one of the 128
characters in the ASCII character set, analogous to "m/[[:ascii:]]/". On non-ASCII
platforms, it returns TRUE iff this character corresponds to an ASCII character.
Variants isASCII_A() and isASCII_L1() are identical to isASCII(). See the top of this
section for an explanation of the variants. Note, however, that some platforms do not
have the C library routine isascii(). In these cases, the variants whose names
contain "LC" are the same as the corresponding ones without.
Also note, that because all ASCII characters are UTF-8 invariant (meaning they have
the exact same representation (always a single byte) whether encoded in UTF-8 or not),
"isASCII" will give the correct results when called with any byte in any string
encoded or not in UTF-8. And similarly "isASCII_utf8" and "isASCII_utf8_safe" will
work properly on any string encoded or not in UTF-8.
bool isASCII (UV ch)
bool isASCII_A (UV ch)
bool isASCII_LC (UV ch)
bool isASCII_LC_utf8_safe(U8 * s, U8 *end)
bool isASCII_LC_uvchr (UV ch)
bool isASCII_L1 (UV ch)
bool isASCII_utf8 (U8 * s, U8 * end)
bool isASCII_utf8_safe (U8 * s, U8 * end)
bool isASCII_uvchr (UV ch)
"isBLANK"
"isBLANK_A"
"isBLANK_LC"
"isBLANK_LC_utf8_safe"
"isBLANK_LC_uvchr"
"isBLANK_L1"
"isBLANK_utf8"
"isBLANK_utf8_safe"
"isBLANK_uvchr"
Returns a boolean indicating whether the specified character is a character considered
to be a blank, analogous to "m/[[:blank:]]/". See the top of this section for an
explanation of the variants. Note, however, that some platforms do not have the C
library routine isblank(). In these cases, the variants whose names contain "LC" are
the same as the corresponding ones without.
bool isBLANK (UV ch)
bool isBLANK_A (UV ch)
bool isBLANK_LC (UV ch)
bool isBLANK_LC_utf8_safe(U8 * s, U8 *end)
bool isBLANK_LC_uvchr (UV ch)
bool isBLANK_L1 (UV ch)
bool isBLANK_utf8 (U8 * s, U8 * end)
bool isBLANK_utf8_safe (U8 * s, U8 * end)
bool isBLANK_uvchr (UV ch)
"isCNTRL"
"isCNTRL_A"
"isCNTRL_LC"
"isCNTRL_LC_utf8_safe"
"isCNTRL_LC_uvchr"
"isCNTRL_L1"
"isCNTRL_utf8"
"isCNTRL_utf8_safe"
"isCNTRL_uvchr"
Returns a boolean indicating whether the specified character is a control character,
analogous to "m/[[:cntrl:]]/". See the top of this section for an explanation of the
variants. On EBCDIC platforms, you almost always want to use the "isCNTRL_L1"
variant.
bool isCNTRL (UV ch)
bool isCNTRL_A (UV ch)
bool isCNTRL_LC (UV ch)
bool isCNTRL_LC_utf8_safe(U8 * s, U8 *end)
bool isCNTRL_LC_uvchr (UV ch)
bool isCNTRL_L1 (UV ch)
bool isCNTRL_utf8 (U8 * s, U8 * end)
bool isCNTRL_utf8_safe (U8 * s, U8 * end)
bool isCNTRL_uvchr (UV ch)
"isDIGIT"
"isDIGIT_A"
"isDIGIT_LC"
"isDIGIT_LC_utf8_safe"
"isDIGIT_LC_uvchr"
"isDIGIT_L1"
"isDIGIT_utf8"
"isDIGIT_utf8_safe"
"isDIGIT_uvchr"
Returns a boolean indicating whether the specified character is a digit, analogous to
"m/[[:digit:]]/". Variants "isDIGIT_A" and "isDIGIT_L1" are identical to "isDIGIT".
See the top of this section for an explanation of the variants.
bool isDIGIT (UV ch)
bool isDIGIT_A (UV ch)
bool isDIGIT_LC (UV ch)
bool isDIGIT_LC_utf8_safe(U8 * s, U8 *end)
bool isDIGIT_LC_uvchr (UV ch)
bool isDIGIT_L1 (UV ch)
bool isDIGIT_utf8 (U8 * s, U8 * end)
bool isDIGIT_utf8_safe (U8 * s, U8 * end)
bool isDIGIT_uvchr (UV ch)
"isGRAPH"
"isGRAPH_A"
"isGRAPH_LC"
"isGRAPH_LC_utf8_safe"
"isGRAPH_LC_uvchr"
"isGRAPH_L1"
"isGRAPH_utf8"
"isGRAPH_utf8_safe"
"isGRAPH_uvchr"
Returns a boolean indicating whether the specified character is a graphic character,
analogous to "m/[[:graph:]]/". See the top of this section for an explanation of the
variants.
bool isGRAPH (UV ch)
bool isGRAPH_A (UV ch)
bool isGRAPH_LC (UV ch)
bool isGRAPH_LC_utf8_safe(U8 * s, U8 *end)
bool isGRAPH_LC_uvchr (UV ch)
bool isGRAPH_L1 (UV ch)
bool isGRAPH_utf8 (U8 * s, U8 * end)
bool isGRAPH_utf8_safe (U8 * s, U8 * end)
bool isGRAPH_uvchr (UV ch)
"isIDCONT"
"isIDCONT_A"
"isIDCONT_LC"
"isIDCONT_LC_utf8_safe"
"isIDCONT_LC_uvchr"
"isIDCONT_L1"
"isIDCONT_utf8"
"isIDCONT_utf8_safe"
"isIDCONT_uvchr"
Returns a boolean indicating whether the specified character can be the second or
succeeding character of an identifier. This is very close to, but not quite the same
as the official Unicode property "XID_Continue". The difference is that this returns
true only if the input character also matches "isWORDCHAR". See the top of this
section for an explanation of the variants.
bool isIDCONT (UV ch)
bool isIDCONT_A (UV ch)
bool isIDCONT_LC (UV ch)
bool isIDCONT_LC_utf8_safe(U8 * s, U8 *end)
bool isIDCONT_LC_uvchr (UV ch)
bool isIDCONT_L1 (UV ch)
bool isIDCONT_utf8 (U8 * s, U8 * end)
bool isIDCONT_utf8_safe (U8 * s, U8 * end)
bool isIDCONT_uvchr (UV ch)
"isIDFIRST"
"isIDFIRST_A"
"isIDFIRST_LC"
"isIDFIRST_LC_utf8_safe"
"isIDFIRST_LC_uvchr"
"isIDFIRST_L1"
"isIDFIRST_utf8"
"isIDFIRST_utf8_safe"
"isIDFIRST_uvchr"
Returns a boolean indicating whether the specified character can be the first
character of an identifier. This is very close to, but not quite the same as the
official Unicode property "XID_Start". The difference is that this returns true only
if the input character also matches "isWORDCHAR". See the top of this section for an
explanation of the variants.
bool isIDFIRST (UV ch)
bool isIDFIRST_A (UV ch)
bool isIDFIRST_LC (UV ch)
bool isIDFIRST_LC_utf8_safe(U8 * s, U8 *end)
bool isIDFIRST_LC_uvchr (UV ch)
bool isIDFIRST_L1 (UV ch)
bool isIDFIRST_utf8 (U8 * s, U8 * end)
bool isIDFIRST_utf8_safe (U8 * s, U8 * end)
bool isIDFIRST_uvchr (UV ch)
"isLOWER"
"isLOWER_A"
"isLOWER_LC"
"isLOWER_LC_utf8_safe"
"isLOWER_LC_uvchr"
"isLOWER_L1"
"isLOWER_utf8"
"isLOWER_utf8_safe"
"isLOWER_uvchr"
Returns a boolean indicating whether the specified character is a lowercase character,
analogous to "m/[[:lower:]]/". See the top of this section for an explanation of the
variants
bool isLOWER (UV ch)
bool isLOWER_A (UV ch)
bool isLOWER_LC (UV ch)
bool isLOWER_LC_utf8_safe(U8 * s, U8 *end)
bool isLOWER_LC_uvchr (UV ch)
bool isLOWER_L1 (UV ch)
bool isLOWER_utf8 (U8 * s, U8 * end)
bool isLOWER_utf8_safe (U8 * s, U8 * end)
bool isLOWER_uvchr (UV ch)
"isOCTAL"
"isOCTAL_A"
"isOCTAL_L1"
Returns a boolean indicating whether the specified character is an octal digit, [0-7].
The only two variants are "isOCTAL_A" and "isOCTAL_L1"; each is identical to
"isOCTAL".
bool isOCTAL(UV ch)
"isPRINT"
"isPRINT_A"
"isPRINT_LC"
"isPRINT_LC_utf8_safe"
"isPRINT_LC_uvchr"
"isPRINT_L1"
"isPRINT_utf8"
"isPRINT_utf8_safe"
"isPRINT_uvchr"
Returns a boolean indicating whether the specified character is a printable character,
analogous to "m/[[:print:]]/". See the top of this section for an explanation of the
variants.
bool isPRINT (UV ch)
bool isPRINT_A (UV ch)
bool isPRINT_LC (UV ch)
bool isPRINT_LC_utf8_safe(U8 * s, U8 *end)
bool isPRINT_LC_uvchr (UV ch)
bool isPRINT_L1 (UV ch)
bool isPRINT_utf8 (U8 * s, U8 * end)
bool isPRINT_utf8_safe (U8 * s, U8 * end)
bool isPRINT_uvchr (UV ch)
"isPSXSPC"
"isPSXSPC_A"
"isPSXSPC_LC"
"isPSXSPC_LC_utf8_safe"
"isPSXSPC_LC_uvchr"
"isPSXSPC_L1"
"isPSXSPC_utf8"
"isPSXSPC_utf8_safe"
"isPSXSPC_uvchr"
(short for Posix Space) Starting in 5.18, this is identical in all its forms to the
corresponding isSPACE() macros. The locale forms of this macro are identical to their
corresponding isSPACE() forms in all Perl releases. In releases prior to 5.18, the
non-locale forms differ from their isSPACE() forms only in that the isSPACE() forms
don't match a Vertical Tab, and the isPSXSPC() forms do. Otherwise they are
identical. Thus this macro is analogous to what "m/[[:space:]]/" matches in a regular
expression. See the top of this section for an explanation of the variants.
bool isPSXSPC (UV ch)
bool isPSXSPC_A (UV ch)
bool isPSXSPC_LC (UV ch)
bool isPSXSPC_LC_utf8_safe(U8 * s, U8 *end)
bool isPSXSPC_LC_uvchr (UV ch)
bool isPSXSPC_L1 (UV ch)
bool isPSXSPC_utf8 (U8 * s, U8 * end)
bool isPSXSPC_utf8_safe (U8 * s, U8 * end)
bool isPSXSPC_uvchr (UV ch)
"isPUNCT"
"isPUNCT_A"
"isPUNCT_LC"
"isPUNCT_LC_utf8_safe"
"isPUNCT_LC_uvchr"
"isPUNCT_L1"
"isPUNCT_utf8"
"isPUNCT_utf8_safe"
"isPUNCT_uvchr"
Returns a boolean indicating whether the specified character is a punctuation
character, analogous to "m/[[:punct:]]/". Note that the definition of what is
punctuation isn't as straightforward as one might desire. See "POSIX Character
Classes" in perlrecharclass for details. See the top of this section for an
explanation of the variants.
bool isPUNCT (UV ch)
bool isPUNCT_A (UV ch)
bool isPUNCT_LC (UV ch)
bool isPUNCT_LC_utf8_safe(U8 * s, U8 *end)
bool isPUNCT_LC_uvchr (UV ch)
bool isPUNCT_L1 (UV ch)
bool isPUNCT_utf8 (U8 * s, U8 * end)
bool isPUNCT_utf8_safe (U8 * s, U8 * end)
bool isPUNCT_uvchr (UV ch)
"isSPACE"
"isSPACE_A"
"isSPACE_LC"
"isSPACE_LC_utf8_safe"
"isSPACE_LC_uvchr"
"isSPACE_L1"
"isSPACE_utf8"
"isSPACE_utf8_safe"
"isSPACE_uvchr"
Returns a boolean indicating whether the specified character is a whitespace
character. This is analogous to what "m/\s/" matches in a regular expression.
Starting in Perl 5.18 this also matches what "m/[[:space:]]/" does. Prior to 5.18,
only the locale forms of this macro (the ones with "LC" in their names) matched
precisely what "m/[[:space:]]/" does. In those releases, the only difference, in the
non-locale variants, was that isSPACE() did not match a vertical tab. (See "isPSXSPC"
for a macro that matches a vertical tab in all releases.) See the top of this section
for an explanation of the variants.
bool isSPACE (UV ch)
bool isSPACE_A (UV ch)
bool isSPACE_LC (UV ch)
bool isSPACE_LC_utf8_safe(U8 * s, U8 *end)
bool isSPACE_LC_uvchr (UV ch)
bool isSPACE_L1 (UV ch)
bool isSPACE_utf8 (U8 * s, U8 * end)
bool isSPACE_utf8_safe (U8 * s, U8 * end)
bool isSPACE_uvchr (UV ch)
"isUPPER"
"isUPPER_A"
"isUPPER_LC"
"isUPPER_LC_utf8_safe"
"isUPPER_LC_uvchr"
"isUPPER_L1"
"isUPPER_utf8"
"isUPPER_utf8_safe"
"isUPPER_uvchr"
Returns a boolean indicating whether the specified character is an uppercase
character, analogous to "m/[[:upper:]]/". See the top of this section for an
explanation of the variants.
bool isUPPER (UV ch)
bool isUPPER_A (UV ch)
bool isUPPER_LC (UV ch)
bool isUPPER_LC_utf8_safe(U8 * s, U8 *end)
bool isUPPER_LC_uvchr (UV ch)
bool isUPPER_L1 (UV ch)
bool isUPPER_utf8 (U8 * s, U8 * end)
bool isUPPER_utf8_safe (U8 * s, U8 * end)
bool isUPPER_uvchr (UV ch)
"isWORDCHAR"
"isWORDCHAR_A"
"isWORDCHAR_LC"
"isWORDCHAR_LC_utf8_safe"
"isWORDCHAR_LC_uvchr"
"isWORDCHAR_L1"
"isWORDCHAR_utf8"
"isWORDCHAR_utf8_safe"
"isWORDCHAR_uvchr"
Returns a boolean indicating whether the specified character is a character that is a
word character, analogous to what "m/\w/" and "m/[[:word:]]/" match in a regular
expression. A word character is an alphabetic character, a decimal digit, a
connecting punctuation character (such as an underscore), or a "mark" character that
attaches to one of those (like some sort of accent).
See the top of this section for an explanation of the variants.
"isWORDCHAR_A", "isWORDCHAR_L1", "isWORDCHAR_uvchr", "isWORDCHAR_LC",
"isWORDCHAR_LC_uvchr", "isWORDCHAR_LC_utf8", and "isWORDCHAR_LC_utf8_safe" are also as
described there, but additionally include the platform's native underscore.
bool isWORDCHAR (UV ch)
bool isWORDCHAR_A (UV ch)
bool isWORDCHAR_LC (UV ch)
bool isWORDCHAR_LC_utf8_safe(U8 * s, U8 *end)
bool isWORDCHAR_LC_uvchr (UV ch)
bool isWORDCHAR_L1 (UV ch)
bool isWORDCHAR_utf8 (U8 * s, U8 * end)
bool isWORDCHAR_utf8_safe (U8 * s, U8 * end)
bool isWORDCHAR_uvchr (UV ch)
"isXDIGIT"
"isXDIGIT_A"
"isXDIGIT_LC"
"isXDIGIT_LC_utf8_safe"
"isXDIGIT_LC_uvchr"
"isXDIGIT_L1"
"isXDIGIT_utf8"
"isXDIGIT_utf8_safe"
"isXDIGIT_uvchr"
Returns a boolean indicating whether the specified character is a hexadecimal digit.
In the ASCII range these are "[0-9A-Fa-f]". Variants isXDIGIT_A() and isXDIGIT_L1()
are identical to isXDIGIT(). See the top of this section for an explanation of the
variants.
bool isXDIGIT (UV ch)
bool isXDIGIT_A (UV ch)
bool isXDIGIT_LC (UV ch)
bool isXDIGIT_LC_utf8_safe(U8 * s, U8 *end)
bool isXDIGIT_LC_uvchr (UV ch)
bool isXDIGIT_L1 (UV ch)
bool isXDIGIT_utf8 (U8 * s, U8 * end)
bool isXDIGIT_utf8_safe (U8 * s, U8 * end)
bool isXDIGIT_uvchr (UV ch)
Compiler and Preprocessor information
"CPPLAST"
This symbol is intended to be used along with "CPPRUN" in the same manner symbol
"CPPMINUS" is used with "CPPSTDIN". It contains either "-" or "".
"CPPMINUS"
This symbol contains the second part of the string which will invoke the C
preprocessor on the standard input and produce to standard output. This symbol will
have the value "-" if "CPPSTDIN" needs a minus to specify standard input, otherwise
the value is "".
"CPPRUN"
This symbol contains the string which will invoke a C preprocessor on the standard
input and produce to standard output. It needs to end with "CPPLAST", after all other
preprocessor flags have been specified. The main difference with "CPPSTDIN" is that
this program will never be a pointer to a shell wrapper, i.e. it will be empty if no
preprocessor is available directly to the user. Note that it may well be different
from the preprocessor used to compile the C program.
"CPPSTDIN"
This symbol contains the first part of the string which will invoke the C preprocessor
on the standard input and produce to standard output. Typical value of "cc -E" or
"/lib/cpp", but it can also call a wrapper. See "CPPRUN".
"HASATTRIBUTE_ALWAYS_INLINE"
Can we handle "GCC" attribute for functions that should always be inlined.
"HASATTRIBUTE_DEPRECATED"
Can we handle "GCC" attribute for marking deprecated "APIs"
"HASATTRIBUTE_FORMAT"
Can we handle "GCC" attribute for checking printf-style formats
"HASATTRIBUTE_NONNULL"
Can we handle "GCC" attribute for nonnull function parms.
"HASATTRIBUTE_NORETURN"
Can we handle "GCC" attribute for functions that do not return
"HASATTRIBUTE_PURE"
Can we handle "GCC" attribute for pure functions
"HASATTRIBUTE_UNUSED"
Can we handle "GCC" attribute for unused variables and arguments
"HASATTRIBUTE_VISIBILITY"
Can we handle "GCC" attribute for functions that should have a different visibility.
"HASATTRIBUTE_WARN_UNUSED_RESULT"
Can we handle "GCC" attribute for warning on unused results
"HAS_BUILTIN_ADD_OVERFLOW"
This symbol, if defined, indicates that the compiler supports "__builtin_add_overflow"
for adding integers with overflow checks.
"HAS_BUILTIN_CHOOSE_EXPR"
Can we handle "GCC" builtin for compile-time ternary-like expressions
"HAS_BUILTIN_EXPECT"
Can we handle "GCC" builtin for telling that certain values are more likely
"HAS_BUILTIN_MUL_OVERFLOW"
This symbol, if defined, indicates that the compiler supports "__builtin_mul_overflow"
for multiplying integers with overflow checks.
"HAS_BUILTIN_SUB_OVERFLOW"
This symbol, if defined, indicates that the compiler supports "__builtin_sub_overflow"
for subtracting integers with overflow checks.
"HAS_C99_VARIADIC_MACROS"
If defined, the compiler supports C99 variadic macros.
"HAS_STATIC_INLINE"
This symbol, if defined, indicates that the C compiler supports C99-style static
inline. That is, the function can't be called from another translation unit.
"MEM_ALIGNBYTES"
This symbol contains the number of bytes required to align a double, or a long double
when applicable. Usual values are 2, 4 and 8. The default is eight, for safety. For
cross-compiling or multiarch support, Configure will set a minimum of 8.
"PERL_STATIC_INLINE"
This symbol gives the best-guess incantation to use for static inline functions. If
"HAS_STATIC_INLINE" is defined, this will give C99-style inline. If
"HAS_STATIC_INLINE" is not defined, this will give a plain 'static'. It will always
be defined to something that gives static linkage. Possibilities include
static inline (c99)
static __inline__ (gcc -ansi)
static __inline (MSVC)
static _inline (older MSVC)
static (c89 compilers)
"PERL_THREAD_LOCAL"
This symbol, if defined, gives a linkage specification for thread-local storage. For
example, for a C11 compiler this will be "_Thread_local". Beware, some compilers are
sensitive to the C language standard they are told to parse. For example, suncc
defaults to C11, so our probe will report that "_Thread_local" can be used. However,
if the -std=c99 is later added to the compiler flags, then "_Thread_local" will become
a syntax error. Hence it is important for these flags to be consistent between probing
and use.
"U32_ALIGNMENT_REQUIRED"
This symbol, if defined, indicates that you must access character data through
U32-aligned pointers.
Compiler directives
"__ASSERT_"
This is a helper macro to avoid preprocessor issues, replaced by nothing unless under
DEBUGGING, where it expands to an assert of its argument, followed by a comma (hence
the comma operator). If we just used a straight assert(), we would get a comma with
nothing before it when not DEBUGGING.
__ASSERT_(bool expr)
"ASSUME"
"ASSUME" is like assert(), but it has a benefit in a release build. It is a hint to a
compiler about a statement of fact in a function call free expression, which allows
the compiler to generate better machine code. In a debug build, ASSUME(x) is a
synonym for assert(x). ASSUME(0) means the control path is unreachable. In a for loop,
"ASSUME" can be used to hint that a loop will run at least X times. "ASSUME" is based
off MSVC's "__assume" intrinsic function, see its documents for more details.
ASSUME(bool expr)
"dNOOP"
Declare nothing; typically used as a placeholder to replace something that used to
declare something. Works on compilers that require declarations before any code.
dNOOP;
"END_EXTERN_C"
When not compiling using C++, expands to nothing. Otherwise ends a section of code
already begun by a "START_EXTERN_C".
END_EXTERN_C
"EXTERN_C"
When not compiling using C++, expands to nothing. Otherwise is used in a declaration
of a function to indicate the function should have external C linkage. This is
required for things to work for just about all functions with external linkage
compiled into perl. Often, you can use "START_EXTERN_C" ... "END_EXTERN_C" blocks
surrounding all your code that you need to have this linkage.
Example usage:
EXTERN_C int flock(int fd, int op);
"LIKELY"
Returns the input unchanged, but at the same time it gives a branch prediction hint to
the compiler that this condition is likely to be true.
LIKELY(bool expr)
"NOOP"
Do nothing; typically used as a placeholder to replace something that used to do
something.
NOOP;
"PERL_UNUSED_ARG"
This is used to suppress compiler warnings that a parameter to a function is not used.
This situation can arise, for example, when a parameter is needed under some
configuration conditions, but not others, so that C preprocessor conditional
compilation causes it be used just sometimes.
PERL_UNUSED_ARG(void x);
"PERL_UNUSED_CONTEXT"
This is used to suppress compiler warnings that the thread context parameter to a
function is not used. This situation can arise, for example, when a C preprocessor
conditional compilation causes it be used just some times.
PERL_UNUSED_CONTEXT;
"PERL_UNUSED_DECL"
Tells the compiler that the parameter in the function prototype just before it is not
necessarily expected to be used in the function. Not that many compilers understand
this, so this should only be used in cases where "PERL_UNUSED_ARG" can't conveniently
be used.
Example usage:
Signal_t
Perl_perly_sighandler(int sig, Siginfo_t *sip PERL_UNUSED_DECL,
void *uap PERL_UNUSED_DECL, bool safe)
"PERL_UNUSED_RESULT"
This macro indicates to discard the return value of the function call inside it, e.g.,
PERL_UNUSED_RESULT(foo(a, b))
The main reason for this is that the combination of "gcc -Wunused-result" (part of
"-Wall") and the "__attribute__((warn_unused_result))" cannot be silenced with casting
to "void". This causes trouble when the system header files use the attribute.
Use "PERL_UNUSED_RESULT" sparingly, though, since usually the warning is there for a
good reason: you might lose success/failure information, or leak resources, or changes
in resources.
But sometimes you just want to ignore the return value, e.g., on codepaths soon ending
up in abort, or in "best effort" attempts, or in situations where there is no good way
to handle failures.
Sometimes "PERL_UNUSED_RESULT" might not be the most natural way: another possibility
is that you can capture the return value and use "PERL_UNUSED_VAR" on that.
PERL_UNUSED_RESULT(void x)
"PERL_UNUSED_VAR"
This is used to suppress compiler warnings that the variable x is not used. This
situation can arise, for example, when a C preprocessor conditional compilation causes
it be used just some times.
PERL_UNUSED_VAR(void x);
"START_EXTERN_C"
When not compiling using C++, expands to nothing. Otherwise begins a section of code
in which every function will effectively have "EXTERN_C" applied to it, that is to
have external C linkage. The section is ended by a "END_EXTERN_C".
START_EXTERN_C
"STATIC"
Described in perlguts.
"STMT_END"
"STMT_START"
These allow a series of statements in a macro to be used as a single statement, as in
if (x) STMT_START { ... } STMT_END else ...
Note that you can't return a value out of this construct and cannot use it as an
operand to the comma operator. These limit its utility.
But, a value could be returned by constructing the API so that a pointer is passed and
the macro dereferences this to set the return. If the value can be any of various
types, depending on context, you can handle that situation in some situations by
adding the type of the return as an extra accompanying parameter:
#define foo(param, type) STMT_START {
type * param; *param = do_calc; ...
} STMT_END
This could be awkward, so consider instead using a C language "static inline"
function.
If you do use this construct, it is easy to forget that it is a macro and not a
function, and hence fall into traps that might not show up until someone someday
writes code which contains names that clash with the ones you chose here, or calls it
with a parameter which is an expression with side effects, the consequences of which
you didn't think about. See "Writing safer macros" in perlhacktips for how to avoid
these.
"UNLIKELY"
Returns the input unchanged, but at the same time it gives a branch prediction hint to
the compiler that this condition is likely to be false.
UNLIKELY(bool expr)
Compile-time scope hooks
"BhkDISABLE"
NOTE: "BhkDISABLE" is experimental and may change or be removed without notice.
Temporarily disable an entry in this BHK structure, by clearing the appropriate flag.
"which" is a preprocessor token indicating which entry to disable.
void BhkDISABLE(BHK *hk, token which)
"BhkENABLE"
NOTE: "BhkENABLE" is experimental and may change or be removed without notice.
Re-enable an entry in this BHK structure, by setting the appropriate flag. "which" is
a preprocessor token indicating which entry to enable. This will assert (under
-DDEBUGGING) if the entry doesn't contain a valid pointer.
void BhkENABLE(BHK *hk, token which)
"BhkENTRY_set"
NOTE: "BhkENTRY_set" is experimental and may change or be removed without notice.
Set an entry in the BHK structure, and set the flags to indicate it is valid. "which"
is a preprocessing token indicating which entry to set. The type of "ptr" depends on
the entry.
void BhkENTRY_set(BHK *hk, token which, void *ptr)
"blockhook_register"
NOTE: "blockhook_register" is experimental and may change or be removed without
notice.
Register a set of hooks to be called when the Perl lexical scope changes at compile
time. See "Compile-time scope hooks" in perlguts.
NOTE: "blockhook_register" must be explicitly called as "Perl_blockhook_register" with
an "aTHX_" parameter.
void Perl_blockhook_register(pTHX_ BHK *hk)
Concurrency
"aTHX"
Described in perlguts.
"aTHX_"
Described in perlguts.
"CPERLscope"
"DEPRECATED!" It is planned to remove "CPERLscope" from a future release of Perl. Do
not use it for new code; remove it from existing code.
Now a no-op.
void CPERLscope(void x)
"dTHR"
Described in perlguts.
"dTHX"
Described in perlguts.
"dTHXa"
On threaded perls, set "pTHX" to "a"; on unthreaded perls, do nothing
"dTHXoa"
Now a synonym for "dTHXa".
"dVAR"
This is now a synonym for dNOOP: declare nothing
"GETENV_PRESERVES_OTHER_THREAD"
This symbol, if defined, indicates that the getenv system call doesn't zap the static
buffer of getenv() in a different thread. The typical getenv() implementation will
return a pointer to the proper position in **environ. But some may instead copy them
to a static buffer in getenv(). If there is a per-thread instance of that buffer, or
the return points to **environ, then a many-reader/1-writer mutex will work; otherwise
an exclusive locking mutex is required to prevent races.
"HAS_PTHREAD_ATFORK"
This symbol, if defined, indicates that the "pthread_atfork" routine is available to
setup fork handlers.
"HAS_PTHREAD_ATTR_SETSCOPE"
This symbol, if defined, indicates that the "pthread_attr_setscope" system call is
available to set the contention scope attribute of a thread attribute object.
"HAS_PTHREAD_YIELD"
This symbol, if defined, indicates that the "pthread_yield" routine is available to
yield the execution of the current thread. "sched_yield" is preferable to
"pthread_yield".
"HAS_SCHED_YIELD"
This symbol, if defined, indicates that the "sched_yield" routine is available to
yield the execution of the current thread. "sched_yield" is preferable to
"pthread_yield".
"I_MACH_CTHREADS"
This symbol, if defined, indicates to the C program that it should include
mach/cthreads.h.
#ifdef I_MACH_CTHREADS
#include <mach_cthreads.h>
#endif
"I_PTHREAD"
This symbol, if defined, indicates to the C program that it should include pthread.h.
#ifdef I_PTHREAD
#include <pthread.h>
#endif
"MULTIPLICITY"
This symbol, if defined, indicates that Perl should be built to use multiplicity.
"OLD_PTHREAD_CREATE_JOINABLE"
This symbol, if defined, indicates how to create pthread in joinable (aka undetached)
state. "NOTE": not defined if pthread.h already has defined "PTHREAD_CREATE_JOINABLE"
(the new version of the constant). If defined, known values are
"PTHREAD_CREATE_UNDETACHED" and "__UNDETACHED".
"OLD_PTHREADS_API"
This symbol, if defined, indicates that Perl should be built to use the old draft
"POSIX" threads "API".
"PERL_IMPLICIT_CONTEXT"
Described in perlguts.
"PERL_NO_GET_CONTEXT"
Described in perlguts.
"pTHX"
Described in perlguts.
"pTHX_"
Described in perlguts.
"SCHED_YIELD"
This symbol defines the way to yield the execution of the current thread. Known ways
are "sched_yield", "pthread_yield", and "pthread_yield" with "NULL".
COPs and Hint Hashes
"cop_fetch_label"
NOTE: "cop_fetch_label" is experimental and may change or be removed without notice.
Returns the label attached to a cop, and stores its length in bytes into *len. Upon
return, *flags will be set to either "SVf_UTF8" or 0.
Alternatively, use the macro "CopLABEL_len_flags"; or if you don't need to know if the
label is UTF-8 or not, the macro "CopLABEL_len"; or if you additionally don't need to
know the length, "CopLABEL".
const char * cop_fetch_label(COP * const cop, STRLEN *len,
U32 *flags)
"CopFILE"
Returns the name of the file associated with the "COP" "c"
const char * CopFILE(const COP * c)
"CopFILEAV"
Returns the AV associated with the "COP" "c", creating it if necessary.
AV * CopFILEAV(const COP * c)
"CopFILEAVn"
Returns the AV associated with the "COP" "c", returning NULL if it doesn't already
exist.
AV * CopFILEAVn(const COP * c)
"CopFILE_copy"
Efficiently copies the cop file name from one COP to another. Wraps the required logic
to do a refcounted copy under threads or not.
void CopFILE_copy(COP * dst, COP * src)
"CopFILE_free"
Frees the file data in a cop. Under the hood this is a refcounting operation.
void CopFILE_free(COP * c)
"CopFILEGV"
Returns the GV associated with the "COP" "c"
GV * CopFILEGV(const COP * c)
"CopFILEGV_set"
Available only on unthreaded perls. Makes "pv" the name of the file associated with
the "COP" "c"
void CopFILEGV_set(COP *c, GV *gv)
"CopFILE_LEN"
Returns the length of the file associated with the "COP" "c"
const char * CopFILE_LEN(const COP * c)
"CopFILE_set"
Makes "pv" the name of the file associated with the "COP" "c"
void CopFILE_set(COP * c, const char * pv)
"CopFILE_setn"
Makes "pv" the name of the file associated with the "COP" "c"
void CopFILE_setn(COP * c, const char * pv, STRLEN len)
"CopFILESV"
Returns the SV associated with the "COP" "c"
SV * CopFILESV(const COP * c)
"cophh_copy"
NOTE: "cophh_copy" is experimental and may change or be removed without notice.
Make and return a complete copy of the cop hints hash "cophh".
COPHH * cophh_copy(COPHH *cophh)
"cophh_delete_pv"
"cophh_delete_pvn"
"cophh_delete_pvs"
"cophh_delete_sv"
NOTE: all these forms are experimental and may change or be removed without notice.
These delete a key and its associated value from the cop hints hash "cophh", and
return the modified hash. The returned hash pointer is in general not the same as the
hash pointer that was passed in. The input hash is consumed by the function, and the
pointer to it must not be subsequently used. Use "cophh_copy" if you need both
hashes.
The forms differ in how the key is specified. In all forms, the key is pointed to by
"key". In the plain "pv" form, the key is a C language NUL-terminated string. In the
"pvs" form, the key is a C language string literal. In the "pvn" form, an additional
parameter, "keylen", specifies the length of the string, which hence, may contain
embedded-NUL characters. In the "sv" form, *key is an SV, and the key is the PV
extracted from that. using "SvPV_const".
"hash" is a precomputed hash of the key string, or zero if it has not been
precomputed. This parameter is omitted from the "pvs" form, as it is computed
automatically at compile time.
The only flag currently used from the "flags" parameter is "COPHH_KEY_UTF8". It is
illegal to set this in the "sv" form. In the "pv*" forms, it specifies whether the
key octets are interpreted as UTF-8 (if set) or as Latin-1 (if cleared). The "sv"
form uses the underlying SV to determine the UTF-8ness of the octets.
COPHH * cophh_delete_pv (COPHH *cophh, const char *key, U32 hash,
U32 flags)
COPHH * cophh_delete_pvn(COPHH *cophh, const char *key,
STRLEN keylen, U32 hash, U32 flags)
COPHH * cophh_delete_pvs(COPHH *cophh, "key", U32 flags)
COPHH * cophh_delete_sv (COPHH *cophh, SV *key, U32 hash,
U32 flags)
"cophh_exists_pvn"
NOTE: "cophh_exists_pvn" is experimental and may change or be removed without notice.
These look up the hint entry in the cop "cop" with the key specified by "key" (and
"keylen" in the "pvn" form), returning true if a value exists, and false otherwise.
The forms differ in how the key is specified. In the plain "pv" form, the key is a C
language NUL-terminated string. In the "pvs" form, the key is a C language string
literal. In the "pvn" form, an additional parameter, "keylen", specifies the length
of the string, which hence, may contain embedded-NUL characters. In the "sv" form,
*key is an SV, and the key is the PV extracted from that. using "SvPV_const".
"hash" is a precomputed hash of the key string, or zero if it has not been
precomputed. This parameter is omitted from the "pvs" form, as it is computed
automatically at compile time.
The only flag currently used from the "flags" parameter is "COPHH_KEY_UTF8". It is
illegal to set this in the "sv" form. In the "pv*" forms, it specifies whether the
key octets are interpreted as UTF-8 (if set) or as Latin-1 (if cleared). The "sv"
form uses the underlying SV to determine the UTF-8ness of the octets.
bool cophh_exists_pvn(const COPHH *cophh, const char *key,
STRLEN keylen, U32 hash, U32 flags)
"cophh_fetch_pv"
"cophh_fetch_pvn"
"cophh_fetch_pvs"
"cophh_fetch_sv"
NOTE: all these forms are experimental and may change or be removed without notice.
These look up the entry in the cop hints hash "cophh" with the key specified by "key"
(and "keylen" in the "pvn" form), returning that value as a mortal scalar copy, or
&PL_sv_placeholder if there is no value associated with the key.
The forms differ in how the key is specified. In the plain "pv" form, the key is a C
language NUL-terminated string. In the "pvs" form, the key is a C language string
literal. In the "pvn" form, an additional parameter, "keylen", specifies the length
of the string, which hence, may contain embedded-NUL characters. In the "sv" form,
*key is an SV, and the key is the PV extracted from that. using "SvPV_const".
"hash" is a precomputed hash of the key string, or zero if it has not been
precomputed. This parameter is omitted from the "pvs" form, as it is computed
automatically at compile time.
The only flag currently used from the "flags" parameter is "COPHH_KEY_UTF8". It is
illegal to set this in the "sv" form. In the "pv*" forms, it specifies whether the
key octets are interpreted as UTF-8 (if set) or as Latin-1 (if cleared). The "sv"
form uses the underlying SV to determine the UTF-8ness of the octets.
SV * cophh_fetch_pv (const COPHH *cophh, const char *key,
U32 hash, U32 flags)
SV * cophh_fetch_pvn(const COPHH *cophh, const char *key,
STRLEN keylen, U32 hash, U32 flags)
SV * cophh_fetch_pvs(const COPHH *cophh, "key", U32 flags)
SV * cophh_fetch_sv (const COPHH *cophh, SV *key, U32 hash,
U32 flags)
"cophh_free"
NOTE: "cophh_free" is experimental and may change or be removed without notice.
Discard the cop hints hash "cophh", freeing all resources associated with it.
void cophh_free(COPHH *cophh)
"cophh_2hv"
NOTE: "cophh_2hv" is experimental and may change or be removed without notice.
Generates and returns a standard Perl hash representing the full set of key/value
pairs in the cop hints hash "cophh". "flags" is currently unused and must be zero.
HV * cophh_2hv(const COPHH *cophh, U32 flags)
"cophh_new_empty"
NOTE: "cophh_new_empty" is experimental and may change or be removed without notice.
Generate and return a fresh cop hints hash containing no entries.
COPHH * cophh_new_empty()
"cophh_store_pv"
"cophh_store_pvn"
"cophh_store_pvs"
"cophh_store_sv"
NOTE: all these forms are experimental and may change or be removed without notice.
These store a value, associated with a key, in the cop hints hash "cophh", and return
the modified hash. The returned hash pointer is in general not the same as the hash
pointer that was passed in. The input hash is consumed by the function, and the
pointer to it must not be subsequently used. Use "cophh_copy" if you need both
hashes.
"value" is the scalar value to store for this key. "value" is copied by these
functions, which thus do not take ownership of any reference to it, and hence later
changes to the scalar will not be reflected in the value visible in the cop hints
hash. Complex types of scalar will not be stored with referential integrity, but will
be coerced to strings.
The forms differ in how the key is specified. In all forms, the key is pointed to by
"key". In the plain "pv" form, the key is a C language NUL-terminated string. In the
"pvs" form, the key is a C language string literal. In the "pvn" form, an additional
parameter, "keylen", specifies the length of the string, which hence, may contain
embedded-NUL characters. In the "sv" form, *key is an SV, and the key is the PV
extracted from that. using "SvPV_const".
"hash" is a precomputed hash of the key string, or zero if it has not been
precomputed. This parameter is omitted from the "pvs" form, as it is computed
automatically at compile time.
The only flag currently used from the "flags" parameter is "COPHH_KEY_UTF8". It is
illegal to set this in the "sv" form. In the "pv*" forms, it specifies whether the
key octets are interpreted as UTF-8 (if set) or as Latin-1 (if cleared). The "sv"
form uses the underlying SV to determine the UTF-8ness of the octets.
COPHH * cophh_store_pv (COPHH *cophh, const char *key, U32 hash,
SV *value, U32 flags)
COPHH * cophh_store_pvn(COPHH *cophh, const char *key,
STRLEN keylen, U32 hash, SV *value,
U32 flags)
COPHH * cophh_store_pvs(COPHH *cophh, "key", SV *value,
U32 flags)
COPHH * cophh_store_sv (COPHH *cophh, SV *key, U32 hash,
SV *value, U32 flags)
"cop_hints_exists_pv"
"cop_hints_exists_pvn"
"cop_hints_exists_pvs"
"cop_hints_exists_sv"
These look up the hint entry in the cop "cop" with the key specified by "key" (and
"keylen" in the "pvn" form), returning true if a value exists, and false otherwise.
The forms differ in how the key is specified. In all forms, the key is pointed to by
"key". In the plain "pv" form, the key is a C language NUL-terminated string. In the
"pvs" form, the key is a C language string literal. In the "pvn" form, an additional
parameter, "keylen", specifies the length of the string, which hence, may contain
embedded-NUL characters. In the "sv" form, *key is an SV, and the key is the PV
extracted from that. using "SvPV_const".
"hash" is a precomputed hash of the key string, or zero if it has not been
precomputed. This parameter is omitted from the "pvs" form, as it is computed
automatically at compile time.
The only flag currently used from the "flags" parameter is "COPHH_KEY_UTF8". It is
illegal to set this in the "sv" form. In the "pv*" forms, it specifies whether the
key octets are interpreted as UTF-8 (if set) or as Latin-1 (if cleared). The "sv"
form uses the underlying SV to determine the UTF-8ness of the octets.
bool cop_hints_exists_pv (const COP *cop, const char *key,
U32 hash, U32 flags)
bool cop_hints_exists_pvn(const COP *cop, const char *key,
STRLEN keylen, U32 hash, U32 flags)
bool cop_hints_exists_pvs(const COP *cop, "key", U32 flags)
bool cop_hints_exists_sv (const COP *cop, SV *key, U32 hash,
U32 flags)
"cop_hints_fetch_pv"
"cop_hints_fetch_pvn"
"cop_hints_fetch_pvs"
"cop_hints_fetch_sv"
These look up the hint entry in the cop "cop" with the key specified by "key" (and
"keylen" in the "pvn" form), returning that value as a mortal scalar copy, or
&PL_sv_placeholder if there is no value associated with the key.
The forms differ in how the key is specified. In the plain "pv" form, the key is a C
language NUL-terminated string. In the "pvs" form, the key is a C language string
literal. In the "pvn" form, an additional parameter, "keylen", specifies the length
of the string, which hence, may contain embedded-NUL characters. In the "sv" form,
*key is an SV, and the key is the PV extracted from that. using "SvPV_const".
"hash" is a precomputed hash of the key string, or zero if it has not been
precomputed. This parameter is omitted from the "pvs" form, as it is computed
automatically at compile time.
The only flag currently used from the "flags" parameter is "COPHH_KEY_UTF8". It is
illegal to set this in the "sv" form. In the "pv*" forms, it specifies whether the
key octets are interpreted as UTF-8 (if set) or as Latin-1 (if cleared). The "sv"
form uses the underlying SV to determine the UTF-8ness of the octets.
SV * cop_hints_fetch_pv (const COP *cop, const char *key,
U32 hash, U32 flags)
SV * cop_hints_fetch_pvn(const COP *cop, const char *key,
STRLEN keylen, U32 hash, U32 flags)
SV * cop_hints_fetch_pvs(const COP *cop, "key", U32 flags)
SV * cop_hints_fetch_sv (const COP *cop, SV *key, U32 hash,
U32 flags)
"cop_hints_2hv"
Generates and returns a standard Perl hash representing the full set of hint entries
in the cop "cop". "flags" is currently unused and must be zero.
HV * cop_hints_2hv(const COP *cop, U32 flags)
"CopLABEL"
"CopLABEL_len"
"CopLABEL_len_flags"
These return the label attached to a cop.
"CopLABEL_len" and "CopLABEL_len_flags" additionally store the number of bytes
comprising the returned label into *len.
"CopLABEL_len_flags" additionally returns the UTF-8ness of the returned label, by
setting *flags to 0 or "SVf_UTF8".
const char * CopLABEL (COP *const cop)
const char * CopLABEL_len (COP *const cop, STRLEN *len)
const char * CopLABEL_len_flags(COP *const cop, STRLEN *len,
U32 *flags)
"CopLINE"
Returns the line number in the source code associated with the "COP" "c"
line_t CopLINE(const COP * c)
"CopSTASH"
Returns the stash associated with "c".
HV * CopSTASH(const COP * c)
"CopSTASH_eq"
Returns a boolean as to whether or not "hv" is the stash associated with "c".
bool CopSTASH_eq(const COP * c, const HV * hv)
"CopSTASHPV"
Returns the package name of the stash associated with "c", or "NULL" if no associated
stash
char * CopSTASHPV(const COP * c)
"CopSTASHPV_set"
Set the package name of the stash associated with "c", to the NUL-terminated C string
"p", creating the package if necessary.
void CopSTASHPV_set(COP * c, const char * pv)
"CopSTASH_set"
Set the stash associated with "c" to "hv".
bool CopSTASH_set(COP * c, HV * hv)
"cop_store_label"
NOTE: "cop_store_label" is experimental and may change or be removed without notice.
Save a label into a "cop_hints_hash". You need to set flags to "SVf_UTF8" for a UTF-8
label. Any other flag is ignored.
void cop_store_label(COP * const cop, const char *label,
STRLEN len, U32 flags)
"PERL_SI"
Use this typedef to declare variables that are to hold "struct stackinfo".
"PL_curcop"
The currently active COP (control op) roughly representing the current statement in
the source.
On threaded perls, each thread has an independent copy of this variable; each
initialized at creation time with the current value of the creating thread's copy.
COP* PL_curcop
"RCPV_LEN"
Returns the length of a pv created with rcpv_new(). Note that this reflects the
length of the string from the callers point of view, it does not include the mandatory
null which is always injected at the end of the string by rcpv_new(). No checks are
performed to ensure that "pv" was actually allocated with rcpv_new(), it is the
callers responsibility to ensure that this is the case.
RCPV * RCPV_LEN(char *pv)
"RCPV_REFCNT_dec"
Decrements the refcount for a "char *" pointer which was created with a call to
rcpv_new(). Same as calling rcpv_free(). No checks are performed to ensure that "pv"
was actually allocated with rcpv_new(), it is the callers responsibility to ensure
that this is the case.
RCPV * RCPV_REFCNT_dec(char *pv)
"RCPV_REFCNT_inc"
Increments the refcount for a "char *" pointer which was created with a call to
rcpv_new(). Same as calling rcpv_copy(). No checks are performed to ensure that "pv"
was actually allocated with rcpv_new(), it is the callers responsibility to ensure
that this is the case.
RCPV * RCPV_REFCNT_inc(char *pv)
"RCPV_REFCOUNT"
Returns the refcount for a pv created with rcpv_new(). No checks are performed to
ensure that "pv" was actually allocated with rcpv_new(), it is the callers
responsibility to ensure that this is the case.
RCPV * RCPV_REFCOUNT(char *pv)
"RCPVx"
Returns the RCPV structure (struct rcpv) for a refcounted string pv created with
rcpv_new(). No checks are performed to ensure that "pv" was actually allocated with
rcpv_new(), it is the callers responsibility to ensure that this is the case.
RCPV * RCPVx(char *pv)
Custom Operators
"custom_op_register"
Register a custom op. See "Custom Operators" in perlguts.
NOTE: "custom_op_register" must be explicitly called as "Perl_custom_op_register" with
an "aTHX_" parameter.
void Perl_custom_op_register(pTHX_ Perl_ppaddr_t ppaddr,
const XOP *xop)
"Perl_custom_op_xop"
Return the XOP structure for a given custom op. This macro should be considered
internal to "OP_NAME" and the other access macros: use them instead. This macro does
call a function. Prior to 5.19.6, this was implemented as a function.
const XOP * Perl_custom_op_xop(pTHX_ const OP *o)
"XopDISABLE"
Temporarily disable a member of the XOP, by clearing the appropriate flag.
void XopDISABLE(XOP *xop, token which)
"XopENABLE"
Reenable a member of the XOP which has been disabled.
void XopENABLE(XOP *xop, token which)
"XopENTRY"
Return a member of the XOP structure. "which" is a cpp token indicating which entry
to return. If the member is not set this will return a default value. The return
type depends on "which". This macro evaluates its arguments more than once. If you
are using "Perl_custom_op_xop" to retrieve a "XOP *" from a "OP *", use the more
efficient "XopENTRYCUSTOM" instead.
XopENTRY(XOP *xop, token which)
"XopENTRYCUSTOM"
Exactly like "XopENTRY(XopENTRY(Perl_custom_op_xop(aTHX_ o), which)" but more
efficient. The "which" parameter is identical to "XopENTRY".
XopENTRYCUSTOM(const OP *o, token which)
"XopENTRY_set"
Set a member of the XOP structure. "which" is a cpp token indicating which entry to
set. See "Custom Operators" in perlguts for details about the available members and
how they are used. This macro evaluates its argument more than once.
void XopENTRY_set(XOP *xop, token which, value)
"XopFLAGS"
Return the XOP's flags.
U32 XopFLAGS(XOP *xop)
CV Handling
This section documents functions to manipulate CVs which are code-values, meaning
subroutines. For more information, see perlguts.
"caller_cx"
The XSUB-writer's equivalent of caller(). The returned "PERL_CONTEXT" structure can
be interrogated to find all the information returned to Perl by "caller". Note that
XSUBs don't get a stack frame, so "caller_cx(0, NULL)" will return information for the
immediately-surrounding Perl code.
This function skips over the automatic calls to &DB::sub made on the behalf of the
debugger. If the stack frame requested was a sub called by "DB::sub", the return
value will be the frame for the call to "DB::sub", since that has the correct line
number/etc. for the call site. If dbcxp is non-"NULL", it will be set to a pointer to
the frame for the sub call itself.
const PERL_CONTEXT * caller_cx(I32 level,
const PERL_CONTEXT **dbcxp)
"CvDEPTH"
Returns the recursion level of the CV "sv". Hence >= 2 indicates we are in a
recursive call.
I32 * CvDEPTH(const CV * const sv)
"CvGV"
Returns the GV associated with the CV "sv", reifying it if necessary.
GV * CvGV(CV *sv)
"CvSTASH"
Returns the stash of the CV. A stash is the symbol table hash, containing the
package-scoped variables in the package where the subroutine was defined. For more
information, see perlguts.
This also has a special use with XS AUTOLOAD subs. See "Autoloading with XSUBs" in
perlguts.
HV* CvSTASH(CV* cv)
"find_runcv"
Locate the CV corresponding to the currently executing sub or eval. If "db_seqp" is
non_null, skip CVs that are in the DB package and populate *db_seqp with the cop
sequence number at the point that the DB:: code was entered. (This allows debuggers
to eval in the scope of the breakpoint rather than in the scope of the debugger
itself.)
CV * find_runcv(U32 *db_seqp)
"get_cv"
"get_cvn_flags"
"get_cvs"
These return the CV of the specified Perl subroutine. "flags" are passed to
"gv_fetchpvn_flags". If "GV_ADD" is set and the Perl subroutine does not exist then
it will be declared (which has the same effect as saying "sub name;"). If "GV_ADD" is
not set and the subroutine does not exist, then NULL is returned.
The forms differ only in how the subroutine is specified.. With "get_cvs", the name
is a literal C string, enclosed in double quotes. With "get_cv", the name is given by
the "name" parameter, which must be a NUL-terminated C string. With "get_cvn_flags",
the name is also given by the "name" parameter, but it is a Perl string (possibly
containing embedded NUL bytes), and its length in bytes is contained in the "len"
parameter.
NOTE: the perl_get_cv() form is deprecated.
NOTE: the perl_get_cvn_flags() form is deprecated.
NOTE: the perl_get_cvs() form is deprecated.
CV * get_cv (const char *name, I32 flags)
CV * get_cvn_flags(const char *name, STRLEN len, I32 flags)
CV * get_cvs ("string", I32 flags)
"Nullcv"
"DEPRECATED!" It is planned to remove "Nullcv" from a future release of Perl. Do not
use it for new code; remove it from existing code.
Null CV pointer.
(deprecated - use "(CV *)NULL" instead)
Debugging
"av_dump"
Dumps the contents of an AV to the "STDERR" filehandle, Similar to using Devel::Peek
on an arrayref but does not expect an RV wrapper. Dumps contents to a depth of 3
levels deep.
void av_dump(AV *av)
"deb"
"deb_nocontext"
When perl is compiled with "-DDEBUGGING", this prints to STDERR the information given
by the arguments, prefaced by the name of the file containing the script causing the
call, and the line number within that file.
If the "v" (verbose) debugging option is in effect, the process id is also printed.
The two forms differ only in that "deb_nocontext" does not take a thread context
("aTHX") parameter, so is used in situations where the caller doesn't already have the
thread context.
NOTE: "deb" must be explicitly called as "Perl_deb" with an "aTHX_" parameter.
void Perl_deb (pTHX_ const char *pat, ...)
void deb_nocontext(const char *pat, ...)
"debstack"
Dump the current stack
I32 debstack()
"dump_all"
Dumps the entire optree of the current program starting at "PL_main_root" to "STDERR".
Also dumps the optrees for all visible subroutines in "PL_defstash".
void dump_all()
"dump_c_backtrace"
Dumps the C backtrace to the given "fp".
Returns true if a backtrace could be retrieved, false if not.
bool dump_c_backtrace(PerlIO *fp, int max_depth, int skip)
"dump_eval"
Described in perlguts.
void dump_eval()
"dump_form"
Dumps the contents of the format contained in the GV "gv" to "STDERR", or a message
that one doesn't exist.
void dump_form(const GV *gv)
"dump_packsubs"
Dumps the optrees for all visible subroutines in "stash".
void dump_packsubs(const HV *stash)
"dump_sub"
Described in perlguts.
void dump_sub(const GV *gv)
"get_c_backtrace_dump"
Returns a SV containing a dump of "depth" frames of the call stack, skipping the
"skip" innermost ones. "depth" of 20 is usually enough.
The appended output looks like:
...
1 10e004812:0082 Perl_croak util.c:1716 /usr/bin/perl
2 10df8d6d2:1d72 perl_parse perl.c:3975 /usr/bin/perl
...
The fields are tab-separated. The first column is the depth (zero being the innermost
non-skipped frame). In the hex:offset, the hex is where the program counter was in
"S_parse_body", and the :offset (might be missing) tells how much inside the
"S_parse_body" the program counter was.
The "util.c:1716" is the source code file and line number.
The /usr/bin/perl is obvious (hopefully).
Unknowns are "-". Unknowns can happen unfortunately quite easily: if the platform
doesn't support retrieving the information; if the binary is missing the debug
information; if the optimizer has transformed the code by for example inlining.
SV * get_c_backtrace_dump(int max_depth, int skip)
"gv_dump"
Dump the name and, if they differ, the effective name of the GV "gv" to "STDERR".
void gv_dump(GV *gv)
"HAS_BACKTRACE"
This symbol, if defined, indicates that the backtrace() routine is available to get a
stack trace. The execinfo.h header must be included to use this routine.
"hv_dump"
Dumps the contents of an HV to the "STDERR" filehandle. Similar to using Devel::Peek
on an hashref but does not expect an RV wrapper. Dumps contents to a depth of 3 levels
deep.
void hv_dump(HV *hv)
"magic_dump"
Dumps the contents of the MAGIC "mg" to "STDERR".
void magic_dump(const MAGIC *mg)
"op_class"
Given an op, determine what type of struct it has been allocated as. Returns one of
the OPclass enums, such as OPclass_LISTOP.
OPclass op_class(const OP *o)
"op_dump"
Dumps the optree starting at OP "o" to "STDERR".
void op_dump(const OP *o)
"PL_op"
Described in perlhacktips.
"PL_runops"
Described in perlguts.
"PL_sv_serial"
Described in perlhacktips.
"pmop_dump"
Dump an OP that is related to Pattern Matching, such as "s/foo/bar/"; these require
special handling.
void pmop_dump(PMOP *pm)
"sv_dump"
Dumps the contents of an SV to the "STDERR" filehandle.
For an example of its output, see Devel::Peek. If the item is an SvROK it will dump
items to a depth of 4, otherwise it will dump only the top level item, which means
that it will not dump the contents of an AV * or HV *. For that use av_dump() or
hv_dump().
void sv_dump(SV *sv)
"sv_dump_depth"
Dumps the contents of an SV to the "STDERR" filehandle to the depth requested. This
function can be used on any SV derived type (GV, HV, AV) with an appropriate cast.
This is a more flexible variant of sv_dump(). For example
HV *hv = ...;
sv_dump_depth((SV*)hv, 2);
would dump the hv, its keys and values, but would not recurse into any RV values.
void sv_dump_depth(SV *sv, I32 depth)
"vdeb"
This is like "deb", but "args" are an encapsulated argument list.
void vdeb(const char *pat, va_list *args)
Display functions
"form"
"form_nocontext"
These take a sprintf-style format pattern and conventional (non-SV) arguments and
return the formatted string.
(char *) Perl_form(aTHX_ const char* pat, ...)
They can be used any place a string (char *) is required:
char * s = form_nocontext("%d.%d", major, minor);
They each return a temporary that will be freed "soon", automatically by the system,
at the same time that SVs operated on by "sv_2mortal" are freed.
Use the result immediately, or copy to a stable place for longer retention. This is
contrary to the incorrect previous documentation of these that claimed that the return
was a single per-thread buffer. That was (and is) actually true only when these are
called during global destruction.
The two forms differ only in that "form_nocontext" does not take a thread context
("aTHX") parameter, so is used in situations where the caller doesn't already have the
thread context.
"vform" is the same except the arguments are an encapsulated argument list.
NOTE: "form" must be explicitly called as "Perl_form" with an "aTHX_" parameter.
char * Perl_form (pTHX_ const char *pat, ...)
char * form_nocontext(const char *pat, ...)
"mess"
"mess_nocontext"
These take a sprintf-style format pattern and argument list, which are used to
generate a string message. If the message does not end with a newline, then it will
be extended with some indication of the current location in the code, as described for
"mess_sv".
Normally, the resulting message is returned in a new mortal SV. But during global
destruction a single SV may be shared between uses of this function.
The two forms differ only in that "mess_nocontext" does not take a thread context
("aTHX") parameter, so is used in situations where the caller doesn't already have the
thread context.
NOTE: "mess" must be explicitly called as "Perl_mess" with an "aTHX_" parameter.
SV * Perl_mess (pTHX_ const char *pat, ...)
SV * mess_nocontext(const char *pat, ...)
"mess_sv"
Expands a message, intended for the user, to include an indication of the current
location in the code, if the message does not already appear to be complete.
"basemsg" is the initial message or object. If it is a reference, it will be used as-
is and will be the result of this function. Otherwise it is used as a string, and if
it already ends with a newline, it is taken to be complete, and the result of this
function will be the same string. If the message does not end with a newline, then a
segment such as "at foo.pl line 37" will be appended, and possibly other clauses
indicating the current state of execution. The resulting message will end with a dot
and a newline.
Normally, the resulting message is returned in a new mortal SV. During global
destruction a single SV may be shared between uses of this function. If "consume" is
true, then the function is permitted (but not required) to modify and return "basemsg"
instead of allocating a new SV.
SV * mess_sv(SV *basemsg, bool consume)
"pv_display"
Similar to
pv_escape(dsv,pv,cur,pvlim,PERL_PV_ESCAPE_QUOTE);
except that an additional "\0" will be appended to the string when len > cur and
pv[cur] is "\0".
Note that the final string may be up to 7 chars longer than pvlim.
char * pv_display(SV *dsv, const char *pv, STRLEN cur,
STRLEN len, STRLEN pvlim)
"pv_escape"
Escapes at most the first "count" chars of "pv" and puts the results into "dsv" such
that the size of the escaped string will not exceed "max" chars and will not contain
any incomplete escape sequences. The number of bytes escaped will be returned in the
"STRLEN *escaped" parameter if it is not null. When the "dsv" parameter is null no
escaping actually occurs, but the number of bytes that would be escaped were it not
null will be calculated.
If flags contains "PERL_PV_ESCAPE_QUOTE" then any double quotes in the string will
also be escaped.
Normally the SV will be cleared before the escaped string is prepared, but when
"PERL_PV_ESCAPE_NOCLEAR" is set this will not occur.
If "PERL_PV_ESCAPE_UNI" is set then the input string is treated as UTF-8. If
"PERL_PV_ESCAPE_UNI_DETECT" is set then the input string is scanned using
is_utf8_string() to determine if it is UTF-8.
If "PERL_PV_ESCAPE_ALL" is set then all input chars will be output using "\x01F1"
style escapes, otherwise if "PERL_PV_ESCAPE_NONASCII" is set, only non-ASCII chars
will be escaped using this style; otherwise, only chars above 255 will be so escaped;
other non printable chars will use octal or common escaped patterns like "\n".
Otherwise, if "PERL_PV_ESCAPE_NOBACKSLASH" then all chars below 255 will be treated as
printable and will be output as literals. The "PERL_PV_ESCAPE_NON_WC" modifies the
previous rules to cause word chars, unicode or otherwise, to be output as literals,
note this uses the *unicode* rules for deciding on word characters.
If "PERL_PV_ESCAPE_FIRSTCHAR" is set then only the first char of the string will be
escaped, regardless of max. If the output is to be in hex, then it will be returned as
a plain hex sequence. Thus the output will either be a single char, an octal escape
sequence, a special escape like "\n" or a hex value.
If "PERL_PV_ESCAPE_RE" is set then the escape char used will be a "%" and not a "\\".
This is because regexes very often contain backslashed sequences, whereas "%" is not a
particularly common character in patterns.
Returns a pointer to the escaped text as held by "dsv".
char * pv_escape(SV *dsv, char const * const str,
const STRLEN count, STRLEN max,
STRLEN * const escaped, U32 flags)
"pv_pretty"
Converts a string into something presentable, handling escaping via pv_escape() and
supporting quoting and ellipses.
If the "PERL_PV_PRETTY_QUOTE" flag is set then the result will be double quoted with
any double quotes in the string escaped. Otherwise if the "PERL_PV_PRETTY_LTGT" flag
is set then the result be wrapped in angle brackets.
If the "PERL_PV_PRETTY_ELLIPSES" flag is set and not all characters in string were
output then an ellipsis "..." will be appended to the string. Note that this happens
AFTER it has been quoted.
If "start_color" is non-null then it will be inserted after the opening quote (if
there is one) but before the escaped text. If "end_color" is non-null then it will be
inserted after the escaped text but before any quotes or ellipses.
Returns a pointer to the prettified text as held by "dsv".
char * pv_pretty(SV *dsv, char const * const str,
const STRLEN count, const STRLEN max,
char const * const start_color,
char const * const end_color, const U32 flags)
"vform"
Like "form" except the arguments are an encapsulated argument list.
char * vform(const char *pat, va_list *args)
"vmess"
"pat" and "args" are a sprintf-style format pattern and encapsulated argument list,
respectively. These are used to generate a string message. If the message does not
end with a newline, then it will be extended with some indication of the current
location in the code, as described for "mess_sv".
Normally, the resulting message is returned in a new mortal SV. During global
destruction a single SV may be shared between uses of this function.
SV * vmess(const char *pat, va_list *args)
Embedding, Threads, and Interpreter Cloning
"call_atexit"
Add a function "fn" to the list of functions to be called at global destruction.
"ptr" will be passed as an argument to "fn"; it can point to a "struct" so that you
can pass anything you want.
Note that under threads, "fn" may run multiple times. This is because the list is
executed each time the current or any descendent thread terminates.
void call_atexit(ATEXIT_t fn, void *ptr)
"cv_clone"
Clone a CV, making a lexical closure. "proto" supplies the prototype of the function:
its code, pad structure, and other attributes. The prototype is combined with a
capture of outer lexicals to which the code refers, which are taken from the
currently-executing instance of the immediately surrounding code.
CV * cv_clone(CV *proto)
"cv_name"
Returns an SV containing the name of the CV, mainly for use in error reporting. The
CV may actually be a GV instead, in which case the returned SV holds the GV's name.
Anything other than a GV or CV is treated as a string already holding the sub name,
but this could change in the future.
An SV may be passed as a second argument. If so, the name will be assigned to it and
it will be returned. Otherwise the returned SV will be a new mortal.
If "flags" has the "CV_NAME_NOTQUAL" bit set, then the package name will not be
included. If the first argument is neither a CV nor a GV, this flag is ignored
(subject to change).
SV * cv_name(CV *cv, SV *sv, U32 flags)
"cv_undef"
Clear out all the active components of a CV. This can happen either by an explicit
"undef &foo", or by the reference count going to zero. In the former case, we keep
the "CvOUTSIDE" pointer, so that any anonymous children can still follow the full
lexical scope chain.
void cv_undef(CV *cv)
"find_rundefsv"
Returns the global variable $_.
SV * find_rundefsv()
"get_op_descs"
"DEPRECATED!" It is planned to remove "get_op_descs" from a future release of Perl.
Do not use it for new code; remove it from existing code.
Return a pointer to the array of all the descriptions of the various OPs Given an
opcode from the enum in opcodes.h, "PL_op_desc[opcode]" returns a pointer to a C
language string giving its description.
char ** get_op_descs()
"get_op_names"
"DEPRECATED!" It is planned to remove "get_op_names" from a future release of Perl.
Do not use it for new code; remove it from existing code.
Return a pointer to the array of all the names of the various OPs Given an opcode from
the enum in opcodes.h, "PL_op_name[opcode]" returns a pointer to a C language string
giving its name.
char ** get_op_names()
"HAS_SKIP_LOCALE_INIT"
Described in perlembed.
"intro_my"
"Introduce" "my" variables to visible status. This is called during parsing at the
end of each statement to make lexical variables visible to subsequent statements.
U32 intro_my()
"load_module"
"load_module_nocontext"
These load the module whose name is pointed to by the string part of "name". Note
that the actual module name, not its filename, should be given. Eg, "Foo::Bar"
instead of "Foo/Bar.pm". ver, if specified and not NULL, provides version semantics
similar to "use Foo::Bar VERSION". The optional trailing arguments can be used to
specify arguments to the module's import() method, similar to "use Foo::Bar VERSION
LIST"; their precise handling depends on the flags. The flags argument is a bitwise-
ORed collection of any of "PERL_LOADMOD_DENY", "PERL_LOADMOD_NOIMPORT", or
"PERL_LOADMOD_IMPORT_OPS" (or 0 for no flags).
If "PERL_LOADMOD_NOIMPORT" is set, the module is loaded as if with an empty import
list, as in "use Foo::Bar ()"; this is the only circumstance in which the trailing
optional arguments may be omitted entirely. Otherwise, if "PERL_LOADMOD_IMPORT_OPS" is
set, the trailing arguments must consist of exactly one "OP*", containing the op tree
that produces the relevant import arguments. Otherwise, the trailing arguments must
all be "SV*" values that will be used as import arguments; and the list must be
terminated with "(SV*) NULL". If neither "PERL_LOADMOD_NOIMPORT" nor
"PERL_LOADMOD_IMPORT_OPS" is set, the trailing "NULL" pointer is needed even if no
import arguments are desired. The reference count for each specified "SV*" argument is
decremented. In addition, the "name" argument is modified.
If "PERL_LOADMOD_DENY" is set, the module is loaded as if with "no" rather than "use".
"load_module" and "load_module_nocontext" have the same apparent signature, but the
former hides the fact that it is accessing a thread context parameter. So use the
latter when you get a compilation error about "pTHX".
void load_module (U32 flags, SV *name, SV *ver, ...)
void load_module_nocontext(U32 flags, SV *name, SV *ver, ...)
"my_exit"
A wrapper for the C library exit(3), honoring what "PL_exit_flags" in perlapi say to
do.
void my_exit(U32 status)
"my_failure_exit"
Exit the running Perl process with an error.
On non-VMS platforms, this is essentially equivalent to ""my_exit"", using "errno",
but forces an en error code of 255 if "errno" is 0.
On VMS, it takes care to set the appropriate severity bits in the exit status.
void my_failure_exit()
"my_strlcat"
The C library "strlcat" if available, or a Perl implementation of it. This operates
on C "NUL"-terminated strings.
my_strlcat() appends string "src" to the end of "dst". It will append at most
"size - strlen(dst) - 1" bytes. It will then "NUL"-terminate, unless "size" is 0 or
the original "dst" string was longer than "size" (in practice this should not happen
as it means that either "size" is incorrect or that "dst" is not a proper
"NUL"-terminated string).
Note that "size" is the full size of the destination buffer and the result is
guaranteed to be "NUL"-terminated if there is room. Note that room for the "NUL"
should be included in "size".
The return value is the total length that "dst" would have if "size" is sufficiently
large. Thus it is the initial length of "dst" plus the length of "src". If "size" is
smaller than the return, the excess was not appended.
Size_t my_strlcat(char *dst, const char *src, Size_t size)
"my_strlcpy"
The C library "strlcpy" if available, or a Perl implementation of it. This operates
on C "NUL"-terminated strings.
my_strlcpy() copies up to "size - 1" bytes from the string "src" to "dst",
"NUL"-terminating the result if "size" is not 0.
The return value is the total length "src" would be if the copy completely succeeded.
If it is larger than "size", the excess was not copied.
Size_t my_strlcpy(char *dst, const char *src, Size_t size)
"newPADNAMELIST"
NOTE: "newPADNAMELIST" is experimental and may change or be removed without notice.
Creates a new pad name list. "max" is the highest index for which space is allocated.
PADNAMELIST * newPADNAMELIST(size_t max)
"newPADNAMEouter"
NOTE: "newPADNAMEouter" is experimental and may change or be removed without notice.
Constructs and returns a new pad name. Only use this function for names that refer to
outer lexicals. (See also "newPADNAMEpvn".) "outer" is the outer pad name that this
one mirrors. The returned pad name has the "PADNAMEf_OUTER" flag already set.
PADNAME * newPADNAMEouter(PADNAME *outer)
"newPADNAMEpvn"
NOTE: "newPADNAMEpvn" is experimental and may change or be removed without notice.
Constructs and returns a new pad name. "s" must be a UTF-8 string. Do not use this
for pad names that point to outer lexicals. See "newPADNAMEouter".
PADNAME * newPADNAMEpvn(const char *s, STRLEN len)
"nothreadhook"
Stub that provides thread hook for perl_destruct when there are no threads.
int nothreadhook()
"pad_add_anon"
Allocates a place in the currently-compiling pad (via "pad_alloc") for an anonymous
function that is lexically scoped inside the currently-compiling function. The
function "func" is linked into the pad, and its "CvOUTSIDE" link to the outer scope is
weakened to avoid a reference loop.
One reference count is stolen, so you may need to do SvREFCNT_inc(func).
"optype" should be an opcode indicating the type of operation that the pad entry is to
support. This doesn't affect operational semantics, but is used for debugging.
PADOFFSET pad_add_anon(CV *func, I32 optype)
"pad_add_name_pv"
Exactly like "pad_add_name_pvn", but takes a nul-terminated string instead of a
string/length pair.
PADOFFSET pad_add_name_pv(const char *name, const U32 flags,
HV *typestash, HV *ourstash)
"pad_add_name_pvn"
Allocates a place in the currently-compiling pad for a named lexical variable. Stores
the name and other metadata in the name part of the pad, and makes preparations to
manage the variable's lexical scoping. Returns the offset of the allocated pad slot.
"namepv"/"namelen" specify the variable's name in UTF-8, including leading sigil. If
"typestash" is non-null, the name is for a typed lexical, and this identifies the
type. If "ourstash" is non-null, it's a lexical reference to a package variable, and
this identifies the package. The following flags can be OR'ed together:
padadd_OUR redundantly specifies if it's a package var
padadd_STATE variable will retain value persistently
padadd_NO_DUP_CHECK skip check for lexical shadowing
padadd_FIELD specifies that the lexical is a field for a class
PADOFFSET pad_add_name_pvn(const char *namepv, STRLEN namelen,
U32 flags, HV *typestash,
HV *ourstash)
"pad_add_name_sv"
Exactly like "pad_add_name_pvn", but takes the name string in the form of an SV
instead of a string/length pair.
PADOFFSET pad_add_name_sv(SV *name, U32 flags, HV *typestash,
HV *ourstash)
"pad_alloc"
NOTE: "pad_alloc" is experimental and may change or be removed without notice.
Allocates a place in the currently-compiling pad, returning the offset of the
allocated pad slot. No name is initially attached to the pad slot. "tmptype" is a
set of flags indicating the kind of pad entry required, which will be set in the value
SV for the allocated pad entry:
SVs_PADMY named lexical variable ("my", "our", "state")
SVs_PADTMP unnamed temporary store
SVf_READONLY constant shared between recursion levels
"SVf_READONLY" has been supported here only since perl 5.20. To work with earlier
versions as well, use "SVf_READONLY|SVs_PADTMP". "SVf_READONLY" does not cause the SV
in the pad slot to be marked read-only, but simply tells "pad_alloc" that it will be
made read-only (by the caller), or at least should be treated as such.
"optype" should be an opcode indicating the type of operation that the pad entry is to
support. This doesn't affect operational semantics, but is used for debugging.
PADOFFSET pad_alloc(I32 optype, U32 tmptype)
"pad_findmy_pv"
Exactly like "pad_findmy_pvn", but takes a nul-terminated string instead of a
string/length pair.
PADOFFSET pad_findmy_pv(const char *name, U32 flags)
"pad_findmy_pvn"
Given the name of a lexical variable, find its position in the currently-compiling
pad. "namepv"/"namelen" specify the variable's name, including leading sigil.
"flags" is reserved and must be zero. If it is not in the current pad but appears in
the pad of any lexically enclosing scope, then a pseudo-entry for it is added in the
current pad. Returns the offset in the current pad, or "NOT_IN_PAD" if no such
lexical is in scope.
PADOFFSET pad_findmy_pvn(const char *namepv, STRLEN namelen,
U32 flags)
"pad_findmy_sv"
Exactly like "pad_findmy_pvn", but takes the name string in the form of an SV instead
of a string/length pair.
PADOFFSET pad_findmy_sv(SV *name, U32 flags)
"padnamelist_fetch"
NOTE: "padnamelist_fetch" is experimental and may change or be removed without notice.
Fetches the pad name from the given index.
PADNAME * padnamelist_fetch(PADNAMELIST *pnl, SSize_t key)
"padnamelist_store"
NOTE: "padnamelist_store" is experimental and may change or be removed without notice.
Stores the pad name (which may be null) at the given index, freeing any existing pad
name in that slot.
PADNAME ** padnamelist_store(PADNAMELIST *pnl, SSize_t key,
PADNAME *val)
"pad_tidy"
NOTE: "pad_tidy" is experimental and may change or be removed without notice.
Tidy up a pad at the end of compilation of the code to which it belongs. Jobs
performed here are: remove most stuff from the pads of anonsub prototypes; give it a
@_; mark temporaries as such. "type" indicates the kind of subroutine:
padtidy_SUB ordinary subroutine
padtidy_SUBCLONE prototype for lexical closure
padtidy_FORMAT format
void pad_tidy(padtidy_type type)
"perl_alloc"
Allocates a new Perl interpreter. See perlembed.
PerlInterpreter * perl_alloc()
"PERL_ASYNC_CHECK"
Described in perlinterp.
void PERL_ASYNC_CHECK()
"perl_clone"
Create and return a new interpreter by cloning the current one.
"perl_clone" takes these flags as parameters:
"CLONEf_COPY_STACKS" - is used to, well, copy the stacks also, without it we only
clone the data and zero the stacks, with it we copy the stacks and the new perl
interpreter is ready to run at the exact same point as the previous one. The pseudo-
fork code uses "COPY_STACKS" while the threads->create doesn't.
"CLONEf_KEEP_PTR_TABLE" - "perl_clone" keeps a ptr_table with the pointer of the old
variable as a key and the new variable as a value, this allows it to check if
something has been cloned and not clone it again, but rather just use the value and
increase the refcount. If "KEEP_PTR_TABLE" is not set then "perl_clone" will kill the
ptr_table using the function "ptr_table_free(PL_ptr_table); PL_ptr_table = NULL;". A
reason to keep it around is if you want to dup some of your own variables which are
outside the graph that perl scans.
"CLONEf_CLONE_HOST" - This is a win32 thing, it is ignored on unix, it tells perl's
win32host code (which is c++) to clone itself, this is needed on win32 if you want to
run two threads at the same time, if you just want to do some stuff in a separate perl
interpreter and then throw it away and return to the original one, you don't need to
do anything.
PerlInterpreter * perl_clone(PerlInterpreter *proto_perl,
UV flags)
"perl_construct"
Initializes a new Perl interpreter. See perlembed.
void perl_construct(PerlInterpreter *my_perl)
"perl_destruct"
Shuts down a Perl interpreter. See perlembed for a tutorial.
"my_perl" points to the Perl interpreter. It must have been previously created
through the use of "perl_alloc" and "perl_construct". It may have been initialised
through "perl_parse", and may have been used through "perl_run" and other means. This
function should be called for any Perl interpreter that has been constructed with
"perl_construct", even if subsequent operations on it failed, for example if
"perl_parse" returned a non-zero value.
If the interpreter's "PL_exit_flags" word has the "PERL_EXIT_DESTRUCT_END" flag set,
then this function will execute code in "END" blocks before performing the rest of
destruction. If it is desired to make any use of the interpreter between "perl_parse"
and "perl_destruct" other than just calling "perl_run", then this flag should be set
early on. This matters if "perl_run" will not be called, or if anything else will be
done in addition to calling "perl_run".
Returns a value be a suitable value to pass to the C library function "exit" (or to
return from "main"), to serve as an exit code indicating the nature of the way the
interpreter terminated. This takes into account any failure of "perl_parse" and any
early exit from "perl_run". The exit code is of the type required by the host
operating system, so because of differing exit code conventions it is not portable to
interpret specific numeric values as having specific meanings.
int perl_destruct(PerlInterpreter *my_perl)
"perl_free"
Releases a Perl interpreter. See perlembed.
void perl_free(PerlInterpreter *my_perl)
"PERL_GET_CONTEXT"
Described in perlguts.
"PerlInterpreter"
Described in perlembed.
"perl_parse"
Tells a Perl interpreter to parse a Perl script. This performs most of the
initialisation of a Perl interpreter. See perlembed for a tutorial.
"my_perl" points to the Perl interpreter that is to parse the script. It must have
been previously created through the use of "perl_alloc" and "perl_construct".
"xsinit" points to a callback function that will be called to set up the ability for
this Perl interpreter to load XS extensions, or may be null to perform no such setup.
"argc" and "argv" supply a set of command-line arguments to the Perl interpreter, as
would normally be passed to the "main" function of a C program. "argv[argc]" must be
null. These arguments are where the script to parse is specified, either by naming a
script file or by providing a script in a "-e" option. If $0 will be written to in
the Perl interpreter, then the argument strings must be in writable memory, and so
mustn't just be string constants.
"env" specifies a set of environment variables that will be used by this Perl
interpreter. If non-null, it must point to a null-terminated array of environment
strings. If null, the Perl interpreter will use the environment supplied by the
"environ" global variable.
This function initialises the interpreter, and parses and compiles the script
specified by the command-line arguments. This includes executing code in "BEGIN",
"UNITCHECK", and "CHECK" blocks. It does not execute "INIT" blocks or the main
program.
Returns an integer of slightly tricky interpretation. The correct use of the return
value is as a truth value indicating whether there was a failure in initialisation.
If zero is returned, this indicates that initialisation was successful, and it is safe
to proceed to call "perl_run" and make other use of it. If a non-zero value is
returned, this indicates some problem that means the interpreter wants to terminate.
The interpreter should not be just abandoned upon such failure; the caller should
proceed to shut the interpreter down cleanly with "perl_destruct" and free it with
"perl_free".
For historical reasons, the non-zero return value also attempts to be a suitable value
to pass to the C library function "exit" (or to return from "main"), to serve as an
exit code indicating the nature of the way initialisation terminated. However, this
isn't portable, due to differing exit code conventions. An attempt is made to return
an exit code of the type required by the host operating system, but because it is
constrained to be non-zero, it is not necessarily possible to indicate every type of
exit. It is only reliable on Unix, where a zero exit code can be augmented with a set
bit that will be ignored. In any case, this function is not the correct place to
acquire an exit code: one should get that from "perl_destruct".
int perl_parse(PerlInterpreter *my_perl, XSINIT_t xsinit,
int argc, char **argv, char **env)
"perl_run"
Tells a Perl interpreter to run its main program. See perlembed for a tutorial.
"my_perl" points to the Perl interpreter. It must have been previously created
through the use of "perl_alloc" and "perl_construct", and initialised through
"perl_parse". This function should not be called if "perl_parse" returned a non-zero
value, indicating a failure in initialisation or compilation.
This function executes code in "INIT" blocks, and then executes the main program. The
code to be executed is that established by the prior call to "perl_parse". If the
interpreter's "PL_exit_flags" word does not have the "PERL_EXIT_DESTRUCT_END" flag
set, then this function will also execute code in "END" blocks. If it is desired to
make any further use of the interpreter after calling this function, then "END" blocks
should be postponed to "perl_destruct" time by setting that flag.
Returns an integer of slightly tricky interpretation. The correct use of the return
value is as a truth value indicating whether the program terminated non-locally. If
zero is returned, this indicates that the program ran to completion, and it is safe to
make other use of the interpreter (provided that the "PERL_EXIT_DESTRUCT_END" flag was
set as described above). If a non-zero value is returned, this indicates that the
interpreter wants to terminate early. The interpreter should not be just abandoned
because of this desire to terminate; the caller should proceed to shut the interpreter
down cleanly with "perl_destruct" and free it with "perl_free".
For historical reasons, the non-zero return value also attempts to be a suitable value
to pass to the C library function "exit" (or to return from "main"), to serve as an
exit code indicating the nature of the way the program terminated. However, this
isn't portable, due to differing exit code conventions. An attempt is made to return
an exit code of the type required by the host operating system, but because it is
constrained to be non-zero, it is not necessarily possible to indicate every type of
exit. It is only reliable on Unix, where a zero exit code can be augmented with a set
bit that will be ignored. In any case, this function is not the correct place to
acquire an exit code: one should get that from "perl_destruct".
int perl_run(PerlInterpreter *my_perl)
"PERL_SET_CONTEXT"
Described in perlguts.
void PERL_SET_CONTEXT(PerlInterpreter* i)
"PERL_SYS_INIT"
"PERL_SYS_INIT3"
These provide system-specific tune up of the C runtime environment necessary to run
Perl interpreters. Only one should be used, and it should be called only once, before
creating any Perl interpreters.
They differ in that "PERL_SYS_INIT3" also initializes "env".
void PERL_SYS_INIT (int *argc, char*** argv)
void PERL_SYS_INIT3(int *argc, char*** argv, char*** env)
"PERL_SYS_TERM"
Provides system-specific clean up of the C runtime environment after running Perl
interpreters. This should be called only once, after freeing any remaining Perl
interpreters.
void PERL_SYS_TERM()
"PL_exit_flags"
Contains flags controlling perl's behaviour on exit():
• "PERL_EXIT_DESTRUCT_END"
If set, END blocks are executed when the interpreter is destroyed. This is
normally set by perl itself after the interpreter is constructed.
• "PERL_EXIT_ABORT"
Call abort() on exit. This is used internally by perl itself to abort if exit is
called while processing exit.
• "PERL_EXIT_WARN"
Warn on exit.
• "PERL_EXIT_EXPECTED"
Set by the "exit" in perlfunc operator.
U8 PL_exit_flags
"PL_origalen"
Described in perlembed.
"PL_perl_destruct_level"
This value may be set when embedding for full cleanup.
Possible values:
• 0 - none
• 1 - full
• 2 or greater - full with checks.
If $ENV{PERL_DESTRUCT_LEVEL} is set to an integer greater than the value of
"PL_perl_destruct_level" its value is used instead.
On threaded perls, each thread has an independent copy of this variable; each
initialized at creation time with the current value of the creating thread's copy.
signed char PL_perl_destruct_level
"ptr_table_fetch"
Look for "sv" in the pointer-mapping table "tbl", returning its value, or NULL if not
found.
void * ptr_table_fetch(PTR_TBL_t * const tbl,
const void * const sv)
"ptr_table_free"
Clear and free a ptr table
void ptr_table_free(PTR_TBL_t * const tbl)
"ptr_table_new"
Create a new pointer-mapping table
PTR_TBL_t * ptr_table_new()
"ptr_table_split"
Double the hash bucket size of an existing ptr table
void ptr_table_split(PTR_TBL_t * const tbl)
"ptr_table_store"
Add a new entry to a pointer-mapping table "tbl". In hash terms, "oldsv" is the key;
Cnewsv> is the value.
The names "old" and "new" are specific to the core's typical use of ptr_tables in
thread cloning.
void ptr_table_store(PTR_TBL_t * const tbl,
const void * const oldsv,
void * const newsv)
"require_pv"
Tells Perl to "require" the file named by the string argument. It is analogous to the
Perl code "eval "require '$file'"". It's even implemented that way; consider using
load_module instead.
NOTE: the perl_require_pv() form is deprecated.
void require_pv(const char *pv)
"vload_module"
Like "load_module" but the arguments are an encapsulated argument list.
void vload_module(U32 flags, SV *name, SV *ver, va_list *args)
Errno
"sv_string_from_errnum"
Generates the message string describing an OS error and returns it as an SV. "errnum"
must be a value that "errno" could take, identifying the type of error.
If "tgtsv" is non-null then the string will be written into that SV (overwriting
existing content) and it will be returned. If "tgtsv" is a null pointer then the
string will be written into a new mortal SV which will be returned.
The message will be taken from whatever locale would be used by $!, and will be
encoded in the SV in whatever manner would be used by $!. The details of this process
are subject to future change. Currently, the message is taken from the C locale by
default (usually producing an English message), and from the currently selected locale
when in the scope of the "use locale" pragma. A heuristic attempt is made to decode
the message from the locale's character encoding, but it will only be decoded as
either UTF-8 or ISO-8859-1. It is always correctly decoded in a UTF-8 locale, usually
in an ISO-8859-1 locale, and never in any other locale.
The SV is always returned containing an actual string, and with no other OK bits set.
Unlike $!, a message is even yielded for "errnum" zero (meaning success), and if no
useful message is available then a useless string (currently empty) is returned.
SV * sv_string_from_errnum(int errnum, SV *tgtsv)
Exception Handling (simple) Macros
"dXCPT"
Set up necessary local variables for exception handling. See "Exception Handling" in
perlguts.
dXCPT;
"JMPENV_JUMP"
Described in perlinterp.
void JMPENV_JUMP(int v)
"JMPENV_PUSH"
Described in perlinterp.
void JMPENV_PUSH(int v)
"PL_restartop"
Described in perlinterp.
"XCPT_CATCH"
Introduces a catch block. See "Exception Handling" in perlguts.
"XCPT_RETHROW"
Rethrows a previously caught exception. See "Exception Handling" in perlguts.
XCPT_RETHROW;
"XCPT_TRY_END"
Ends a try block. See "Exception Handling" in perlguts.
"XCPT_TRY_START"
Starts a try block. See "Exception Handling" in perlguts.
Filesystem configuration values
Also see "List of capability HAS_foo symbols".
"DIRNAMLEN"
This symbol, if defined, indicates to the C program that the length of directory entry
names is provided by a "d_namlen" field. Otherwise you need to do strlen() on the
"d_name" field.
"DOSUID"
This symbol, if defined, indicates that the C program should check the script that it
is executing for setuid/setgid bits, and attempt to emulate setuid/setgid on systems
that have disabled setuid #! scripts because the kernel can't do it securely. It is
up to the package designer to make sure that this emulation is done securely. Among
other things, it should do an fstat on the script it just opened to make sure it
really is a setuid/setgid script, it should make sure the arguments passed correspond
exactly to the argument on the #! line, and it should not trust any subprocesses to
which it must pass the filename rather than the file descriptor of the script to be
executed.
"EOF_NONBLOCK"
This symbol, if defined, indicates to the C program that a read() on a non-blocking
file descriptor will return 0 on "EOF", and not the value held in "RD_NODATA" (-1
usually, in that case!).
"FCNTL_CAN_LOCK"
This symbol, if defined, indicates that fcntl() can be used for file locking.
Normally on Unix systems this is defined. It may be undefined on "VMS".
"FFLUSH_ALL"
This symbol, if defined, tells that to flush all pending stdio output one must loop
through all the stdio file handles stored in an array and fflush them. Note that if
"fflushNULL" is defined, fflushall will not even be probed for and will be left
undefined.
"FFLUSH_NULL"
This symbol, if defined, tells that fflush(NULL) correctly flushes all pending stdio
output without side effects. In particular, on some platforms calling fflush(NULL)
*still* corrupts "STDIN" if it is a pipe.
"FILE_base"
This macro is used to access the "_base" field (or equivalent) of the "FILE" structure
pointed to by its argument. This macro will always be defined if "USE_STDIO_BASE" is
defined.
void * FILE_base(FILE * f)
"FILE_bufsiz"
This macro is used to determine the number of bytes in the I/O buffer pointed to by
"_base" field (or equivalent) of the "FILE" structure pointed to its argument. This
macro will always be defined if "USE_STDIO_BASE" is defined.
Size_t FILE_bufsiz(FILE *f)
"FILE_cnt"
This macro is used to access the "_cnt" field (or equivalent) of the "FILE" structure
pointed to by its argument. This macro will always be defined if "USE_STDIO_PTR" is
defined.
Size_t FILE_cnt(FILE * f)
"FILE_ptr"
This macro is used to access the "_ptr" field (or equivalent) of the "FILE" structure
pointed to by its argument. This macro will always be defined if "USE_STDIO_PTR" is
defined.
void * FILE_ptr(FILE * f)
"FLEXFILENAMES"
This symbol, if defined, indicates that the system supports filenames longer than 14
characters.
"HAS_DIR_DD_FD"
This symbol, if defined, indicates that the "DIR"* dirstream structure contains a
member variable named "dd_fd".
"HAS_DUP2"
This symbol, if defined, indicates that the "dup2" routine is available to duplicate
file descriptors.
"HAS_DUP3"
This symbol, if defined, indicates that the "dup3" routine is available to duplicate
file descriptors.
"HAS_FAST_STDIO"
This symbol, if defined, indicates that the "fast stdio" is available to manipulate
the stdio buffers directly.
"HAS_FCHDIR"
This symbol, if defined, indicates that the "fchdir" routine is available to change
directory using a file descriptor.
"HAS_FCNTL"
This symbol, if defined, indicates to the C program that the fcntl() function exists.
"HAS_FDCLOSE"
This symbol, if defined, indicates that the "fdclose" routine is available to free a
"FILE" structure without closing the underlying file descriptor. This function
appeared in "FreeBSD" 10.2.
"HAS_FPATHCONF"
This symbol, if defined, indicates that pathconf() is available to determine file-
system related limits and options associated with a given open file descriptor.
"HAS_FPOS64_T"
This symbol will be defined if the C compiler supports "fpos64_t".
"HAS_FSTATFS"
This symbol, if defined, indicates that the "fstatfs" routine is available to stat
filesystems by file descriptors.
"HAS_FSTATVFS"
This symbol, if defined, indicates that the "fstatvfs" routine is available to stat
filesystems by file descriptors.
"HAS_GETFSSTAT"
This symbol, if defined, indicates that the "getfsstat" routine is available to stat
filesystems in bulk.
"HAS_GETMNT"
This symbol, if defined, indicates that the "getmnt" routine is available to get
filesystem mount info by filename.
"HAS_GETMNTENT"
This symbol, if defined, indicates that the "getmntent" routine is available to
iterate through mounted file systems to get their info.
"HAS_HASMNTOPT"
This symbol, if defined, indicates that the "hasmntopt" routine is available to query
the mount options of file systems.
"HAS_LSEEK_PROTO"
This symbol, if defined, indicates that the system provides a prototype for the
lseek() function. Otherwise, it is up to the program to supply one. A good guess is
extern off_t lseek(int, off_t, int);
"HAS_MKDIR"
This symbol, if defined, indicates that the "mkdir" routine is available to create
directories. Otherwise you should fork off a new process to exec /bin/mkdir.
"HAS_OFF64_T"
This symbol will be defined if the C compiler supports "off64_t".
"HAS_OPENAT"
This symbol is defined if the openat() routine is available.
"HAS_OPEN3"
This manifest constant lets the C program know that the three argument form of open(2)
is available.
"HAS_POLL"
This symbol, if defined, indicates that the "poll" routine is available to "poll"
active file descriptors. Please check "I_POLL" and "I_SYS_POLL" to know which header
should be included as well.
"HAS_READDIR"
This symbol, if defined, indicates that the "readdir" routine is available to read
directory entries. You may have to include dirent.h. See "I_DIRENT".
"HAS_READDIR64_R"
This symbol, if defined, indicates that the "readdir64_r" routine is available to
readdir64 re-entrantly.
"HAS_REWINDDIR"
This symbol, if defined, indicates that the "rewinddir" routine is available. You may
have to include dirent.h. See "I_DIRENT".
"HAS_RMDIR"
This symbol, if defined, indicates that the "rmdir" routine is available to remove
directories. Otherwise you should fork off a new process to exec /bin/rmdir.
"HAS_SEEKDIR"
This symbol, if defined, indicates that the "seekdir" routine is available. You may
have to include dirent.h. See "I_DIRENT".
"HAS_SELECT"
This symbol, if defined, indicates that the "select" routine is available to "select"
active file descriptors. If the timeout field is used, sys/time.h may need to be
included.
"HAS_SETVBUF"
This symbol, if defined, indicates that the "setvbuf" routine is available to change
buffering on an open stdio stream. to a line-buffered mode.
"HAS_STDIO_STREAM_ARRAY"
This symbol, if defined, tells that there is an array holding the stdio streams.
"HAS_STRUCT_FS_DATA"
This symbol, if defined, indicates that the "struct fs_data" to do statfs() is
supported.
"HAS_STRUCT_STATFS"
This symbol, if defined, indicates that the "struct statfs" to do statfs() is
supported.
"HAS_STRUCT_STATFS_F_FLAGS"
This symbol, if defined, indicates that the "struct statfs" does have the "f_flags"
member containing the mount flags of the filesystem containing the file. This kind of
"struct statfs" is coming from sys/mount.h ("BSD" 4.3), not from sys/statfs.h
("SYSV"). Older "BSDs" (like Ultrix) do not have statfs() and "struct statfs", they
have ustat() and getmnt() with "struct ustat" and "struct fs_data".
"HAS_TELLDIR"
This symbol, if defined, indicates that the "telldir" routine is available. You may
have to include dirent.h. See "I_DIRENT".
"HAS_USTAT"
This symbol, if defined, indicates that the "ustat" system call is available to query
file system statistics by "dev_t".
"I_FCNTL"
This manifest constant tells the C program to include fcntl.h.
#ifdef I_FCNTL
#include <fcntl.h>
#endif
"I_SYS_DIR"
This symbol, if defined, indicates to the C program that it should include sys/dir.h.
#ifdef I_SYS_DIR
#include <sys_dir.h>
#endif
"I_SYS_FILE"
This symbol, if defined, indicates to the C program that it should include sys/file.h
to get definition of "R_OK" and friends.
#ifdef I_SYS_FILE
#include <sys_file.h>
#endif
"I_SYS_NDIR"
This symbol, if defined, indicates to the C program that it should include sys/ndir.h.
#ifdef I_SYS_NDIR
#include <sys_ndir.h>
#endif
"I_SYS_STATFS"
This symbol, if defined, indicates that sys/statfs.h exists.
#ifdef I_SYS_STATFS
#include <sys_statfs.h>
#endif
"LSEEKSIZE"
This symbol holds the number of bytes used by the "Off_t".
"RD_NODATA"
This symbol holds the return code from read() when no data is present on the non-
blocking file descriptor. Be careful! If "EOF_NONBLOCK" is not defined, then you can't
distinguish between no data and "EOF" by issuing a read(). You'll have to find another
way to tell for sure!
"READDIR64_R_PROTO"
This symbol encodes the prototype of "readdir64_r". It is zero if "d_readdir64_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_readdir64_r" is
defined.
"STDCHAR"
This symbol is defined to be the type of char used in stdio.h. It has the values
"unsigned char" or "char".
"STDIO_CNT_LVALUE"
This symbol is defined if the "FILE_cnt" macro can be used as an lvalue.
"STDIO_PTR_LVAL_NOCHANGE_CNT"
This symbol is defined if using the "FILE_ptr" macro as an lvalue to increase the
pointer by n leaves File_cnt(fp) unchanged.
"STDIO_PTR_LVAL_SETS_CNT"
This symbol is defined if using the "FILE_ptr" macro as an lvalue to increase the
pointer by n has the side effect of decreasing the value of File_cnt(fp) by n.
"STDIO_PTR_LVALUE"
This symbol is defined if the "FILE_ptr" macro can be used as an lvalue.
"STDIO_STREAM_ARRAY"
This symbol tells the name of the array holding the stdio streams. Usual values
include "_iob", "__iob", and "__sF".
"ST_INO_SIGN"
This symbol holds the signedness of "struct stat"'s "st_ino". 1 for unsigned, -1 for
signed.
"ST_INO_SIZE"
This variable contains the size of "struct stat"'s "st_ino" in bytes.
"VAL_EAGAIN"
This symbol holds the errno error code set by read() when no data was present on the
non-blocking file descriptor.
"VAL_O_NONBLOCK"
This symbol is to be used during open() or fcntl(F_SETFL) to turn on non-blocking I/O
for the file descriptor. Note that there is no way back, i.e. you cannot turn it
blocking again this way. If you wish to alternatively switch between blocking and non-
blocking, use the ioctl(FIOSNBIO) call instead, but that is not supported by all
devices.
"VOID_CLOSEDIR"
This symbol, if defined, indicates that the closedir() routine does not return a
value.
Floating point
Also "List of capability HAS_foo symbols" lists capabilities that arent in this section.
For example "HAS_ASINH", for the hyperbolic sine function.
"CASTFLAGS"
This symbol contains flags that say what difficulties the compiler has casting odd
floating values to unsigned long:
0 = ok
1 = couldn't cast < 0
2 = couldn't cast >= 0x80000000
4 = couldn't cast in argument expression list
"CASTNEGFLOAT"
This symbol is defined if the C compiler can cast negative numbers to unsigned longs,
ints and shorts.
"DOUBLE_HAS_INF"
This symbol, if defined, indicates that the double has the infinity.
"DOUBLE_HAS_NAN"
This symbol, if defined, indicates that the double has the not-a-number.
"DOUBLE_HAS_NEGATIVE_ZERO"
This symbol, if defined, indicates that the double has the "negative_zero".
"DOUBLE_HAS_SUBNORMALS"
This symbol, if defined, indicates that the double has the subnormals (denormals).
"DOUBLEINFBYTES"
This symbol, if defined, is a comma-separated list of hexadecimal bytes for the double
precision infinity.
"DOUBLEKIND"
"DOUBLEKIND" will be one of "DOUBLE_IS_IEEE_754_32_BIT_LITTLE_ENDIAN"
"DOUBLE_IS_IEEE_754_32_BIT_BIG_ENDIAN" "DOUBLE_IS_IEEE_754_64_BIT_LITTLE_ENDIAN"
"DOUBLE_IS_IEEE_754_64_BIT_BIG_ENDIAN" "DOUBLE_IS_IEEE_754_128_BIT_LITTLE_ENDIAN"
"DOUBLE_IS_IEEE_754_128_BIT_BIG_ENDIAN" "DOUBLE_IS_IEEE_754_64_BIT_MIXED_ENDIAN_LE_BE"
"DOUBLE_IS_IEEE_754_64_BIT_MIXED_ENDIAN_BE_LE" "DOUBLE_IS_VAX_F_FLOAT"
"DOUBLE_IS_VAX_D_FLOAT" "DOUBLE_IS_VAX_G_FLOAT" "DOUBLE_IS_IBM_SINGLE_32_BIT"
"DOUBLE_IS_IBM_DOUBLE_64_BIT" "DOUBLE_IS_CRAY_SINGLE_64_BIT"
"DOUBLE_IS_UNKNOWN_FORMAT"
"DOUBLEMANTBITS"
This symbol, if defined, tells how many mantissa bits there are in double precision
floating point format. Note that this is usually "DBL_MANT_DIG" minus one, since with
the standard "IEEE" 754 formats "DBL_MANT_DIG" includes the implicit bit, which
doesn't really exist.
"DOUBLENANBYTES"
This symbol, if defined, is a comma-separated list of hexadecimal bytes (0xHH) for the
double precision not-a-number.
"DOUBLESIZE"
This symbol contains the size of a double, so that the C preprocessor can make
decisions based on it.
"DOUBLE_STYLE_CRAY"
This symbol, if defined, indicates that the double is the 64-bit "CRAY" mainframe
format.
"DOUBLE_STYLE_IBM"
This symbol, if defined, indicates that the double is the 64-bit "IBM" mainframe
format.
"DOUBLE_STYLE_IEEE"
This symbol, if defined, indicates that the double is the 64-bit "IEEE" 754.
"DOUBLE_STYLE_VAX"
This symbol, if defined, indicates that the double is the 64-bit "VAX" format D or G.
"HAS_ATOLF"
This symbol, if defined, indicates that the "atolf" routine is available to convert
strings into long doubles.
"HAS_CLASS"
This symbol, if defined, indicates that the "class" routine is available to classify
doubles. Available for example in "AIX". The returned values are defined in float.h
and are:
FP_PLUS_NORM Positive normalized, nonzero
FP_MINUS_NORM Negative normalized, nonzero
FP_PLUS_DENORM Positive denormalized, nonzero
FP_MINUS_DENORM Negative denormalized, nonzero
FP_PLUS_ZERO +0.0
FP_MINUS_ZERO -0.0
FP_PLUS_INF +INF
FP_MINUS_INF -INF
FP_NANS Signaling Not a Number (NaNS)
FP_NANQ Quiet Not a Number (NaNQ)
"HAS_FINITE"
This symbol, if defined, indicates that the "finite" routine is available to check
whether a double is "finite" (non-infinity non-NaN).
"HAS_FINITEL"
This symbol, if defined, indicates that the "finitel" routine is available to check
whether a long double is finite (non-infinity non-NaN).
"HAS_FPCLASS"
This symbol, if defined, indicates that the "fpclass" routine is available to classify
doubles. Available for example in Solaris/"SVR4". The returned values are defined in
ieeefp.h and are:
FP_SNAN signaling NaN
FP_QNAN quiet NaN
FP_NINF negative infinity
FP_PINF positive infinity
FP_NDENORM negative denormalized non-zero
FP_PDENORM positive denormalized non-zero
FP_NZERO negative zero
FP_PZERO positive zero
FP_NNORM negative normalized non-zero
FP_PNORM positive normalized non-zero
"HAS_FP_CLASS"
This symbol, if defined, indicates that the "fp_class" routine is available to
classify doubles. Available for example in Digital "UNIX". The returned values are
defined in math.h and are:
FP_SNAN Signaling NaN (Not-a-Number)
FP_QNAN Quiet NaN (Not-a-Number)
FP_POS_INF +infinity
FP_NEG_INF -infinity
FP_POS_NORM Positive normalized
FP_NEG_NORM Negative normalized
FP_POS_DENORM Positive denormalized
FP_NEG_DENORM Negative denormalized
FP_POS_ZERO +0.0 (positive zero)
FP_NEG_ZERO -0.0 (negative zero)
"HAS_FPCLASSIFY"
This symbol, if defined, indicates that the "fpclassify" routine is available to
classify doubles. Available for example in HP-UX. The returned values are defined in
math.h and are
FP_NORMAL Normalized
FP_ZERO Zero
FP_INFINITE Infinity
FP_SUBNORMAL Denormalized
FP_NAN NaN
"HAS_FP_CLASSIFY"
This symbol, if defined, indicates that the "fp_classify" routine is available to
classify doubles. The values are defined in math.h
FP_NORMAL Normalized
FP_ZERO Zero
FP_INFINITE Infinity
FP_SUBNORMAL Denormalized
FP_NAN NaN
"HAS_FPCLASSL"
This symbol, if defined, indicates that the "fpclassl" routine is available to
classify long doubles. Available for example in "IRIX". The returned values are
defined in ieeefp.h and are:
FP_SNAN signaling NaN
FP_QNAN quiet NaN
FP_NINF negative infinity
FP_PINF positive infinity
FP_NDENORM negative denormalized non-zero
FP_PDENORM positive denormalized non-zero
FP_NZERO negative zero
FP_PZERO positive zero
FP_NNORM negative normalized non-zero
FP_PNORM positive normalized non-zero
"HAS_FP_CLASSL"
This symbol, if defined, indicates that the "fp_classl" routine is available to
classify long doubles. Available for example in Digital "UNIX". See for possible
values "HAS_FP_CLASS".
"HAS_FPGETROUND"
This symbol, if defined, indicates that the "fpgetround" routine is available to get
the floating point rounding mode.
"HAS_FREXPL"
This symbol, if defined, indicates that the "frexpl" routine is available to break a
long double floating-point number into a normalized fraction and an integral power of
2.
"HAS_ILOGB"
This symbol, if defined, indicates that the "ilogb" routine is available to get
integer exponent of a floating-point value.
"HAS_ISFINITE"
This symbol, if defined, indicates that the "isfinite" routine is available to check
whether a double is finite (non-infinity non-NaN).
"HAS_ISFINITEL"
This symbol, if defined, indicates that the "isfinitel" routine is available to check
whether a long double is finite. (non-infinity non-NaN).
"HAS_ISINF"
This symbol, if defined, indicates that the "isinf" routine is available to check
whether a double is an infinity.
"HAS_ISINFL"
This symbol, if defined, indicates that the "isinfl" routine is available to check
whether a long double is an infinity.
"HAS_ISNAN"
This symbol, if defined, indicates that the "isnan" routine is available to check
whether a double is a NaN.
"HAS_ISNANL"
This symbol, if defined, indicates that the "isnanl" routine is available to check
whether a long double is a NaN.
"HAS_ISNORMAL"
This symbol, if defined, indicates that the "isnormal" routine is available to check
whether a double is normal (non-zero normalized).
"HAS_J0L"
This symbol, if defined, indicates to the C program that the j0l() function is
available for Bessel functions of the first kind of the order zero, for long doubles.
"HAS_J0"
This symbol, if defined, indicates to the C program that the j0() function is
available for Bessel functions of the first kind of the order zero, for doubles.
"HAS_LDBL_DIG"
This symbol, if defined, indicates that this system's float.h or limits.h defines the
symbol "LDBL_DIG", which is the number of significant digits in a long double
precision number. Unlike for "DBL_DIG", there's no good guess for "LDBL_DIG" if it is
undefined.
"HAS_LDEXPL"
This symbol, if defined, indicates that the "ldexpl" routine is available to shift a
long double floating-point number by an integral power of 2.
"HAS_LLRINT"
This symbol, if defined, indicates that the "llrint" routine is available to return
the long long value closest to a double (according to the current rounding mode).
"HAS_LLRINTL"
This symbol, if defined, indicates that the "llrintl" routine is available to return
the long long value closest to a long double (according to the current rounding mode).
"HAS_LLROUNDL"
This symbol, if defined, indicates that the "llroundl" routine is available to return
the nearest long long value away from zero of the long double argument value.
"HAS_LONG_DOUBLE"
This symbol will be defined if the C compiler supports long doubles.
"HAS_LRINT"
This symbol, if defined, indicates that the "lrint" routine is available to return the
integral value closest to a double (according to the current rounding mode).
"HAS_LRINTL"
This symbol, if defined, indicates that the "lrintl" routine is available to return
the integral value closest to a long double (according to the current rounding mode).
"HAS_LROUNDL"
This symbol, if defined, indicates that the "lroundl" routine is available to return
the nearest integral value away from zero of the long double argument value.
"HAS_MODFL"
This symbol, if defined, indicates that the "modfl" routine is available to split a
long double x into a fractional part f and an integer part i such that |f| < 1.0 and
(f + i) = x.
"HAS_NAN"
This symbol, if defined, indicates that the "nan" routine is available to generate
NaN.
"HAS_NEXTTOWARD"
This symbol, if defined, indicates that the "nexttoward" routine is available to
return the next machine representable long double from x in direction y.
"HAS_REMAINDER"
This symbol, if defined, indicates that the "remainder" routine is available to return
the floating-point "remainder".
"HAS_SCALBN"
This symbol, if defined, indicates that the "scalbn" routine is available to multiply
floating-point number by integral power of radix.
"HAS_SIGNBIT"
This symbol, if defined, indicates that the "signbit" routine is available to check if
the given number has the sign bit set. This should include correct testing of -0.0.
This will only be set if the signbit() routine is safe to use with the NV type used
internally in perl. Users should call Perl_signbit(), which will be #defined to the
system's signbit() function or macro if this symbol is defined.
"HAS_SQRTL"
This symbol, if defined, indicates that the "sqrtl" routine is available to do long
double square roots.
"HAS_STRTOD_L"
This symbol, if defined, indicates that the "strtod_l" routine is available to convert
strings to long doubles.
"HAS_STRTOLD"
This symbol, if defined, indicates that the "strtold" routine is available to convert
strings to long doubles.
"HAS_STRTOLD_L"
This symbol, if defined, indicates that the "strtold_l" routine is available to
convert strings to long doubles.
"HAS_TRUNC"
This symbol, if defined, indicates that the "trunc" routine is available to round
doubles towards zero.
"HAS_UNORDERED"
This symbol, if defined, indicates that the "unordered" routine is available to check
whether two doubles are "unordered" (effectively: whether either of them is NaN)
"I_FENV"
This symbol, if defined, indicates to the C program that it should include fenv.h to
get the floating point environment definitions.
#ifdef I_FENV
#include <fenv.h>
#endif
"I_QUADMATH"
This symbol, if defined, indicates that quadmath.h exists and should be included.
#ifdef I_QUADMATH
#include <quadmath.h>
#endif
"LONGDBLINFBYTES"
This symbol, if defined, is a comma-separated list of hexadecimal bytes for the long
double precision infinity.
"LONGDBLMANTBITS"
This symbol, if defined, tells how many mantissa bits there are in long double
precision floating point format. Note that this can be "LDBL_MANT_DIG" minus one,
since "LDBL_MANT_DIG" can include the "IEEE" 754 implicit bit. The common x86-style
80-bit long double does not have an implicit bit.
"LONGDBLNANBYTES"
This symbol, if defined, is a comma-separated list of hexadecimal bytes (0xHH) for the
long double precision not-a-number.
"LONG_DOUBLEKIND"
"LONG_DOUBLEKIND" will be one of "LONG_DOUBLE_IS_DOUBLE"
"LONG_DOUBLE_IS_IEEE_754_128_BIT_LITTLE_ENDIAN"
"LONG_DOUBLE_IS_IEEE_754_128_BIT_BIG_ENDIAN" "LONG_DOUBLE_IS_X86_80_BIT_LITTLE_ENDIAN"
"LONG_DOUBLE_IS_X86_80_BIT_BIG_ENDIAN" "LONG_DOUBLE_IS_DOUBLEDOUBLE_128_BIT_LE_LE"
"LONG_DOUBLE_IS_DOUBLEDOUBLE_128_BIT_BE_BE"
"LONG_DOUBLE_IS_DOUBLEDOUBLE_128_BIT_LE_BE"
"LONG_DOUBLE_IS_DOUBLEDOUBLE_128_BIT_BE_LE"
"LONG_DOUBLE_IS_DOUBLEDOUBLE_128_BIT_LITTLE_ENDIAN"
"LONG_DOUBLE_IS_DOUBLEDOUBLE_128_BIT_BIG_ENDIAN" "LONG_DOUBLE_IS_VAX_H_FLOAT"
"LONG_DOUBLE_IS_UNKNOWN_FORMAT" It is only defined if the system supports long
doubles.
"LONG_DOUBLESIZE"
This symbol contains the size of a long double, so that the C preprocessor can make
decisions based on it. It is only defined if the system supports long doubles. Note
that this is "sizeof(long double)", which may include unused bytes.
"LONG_DOUBLE_STYLE_IEEE"
This symbol, if defined, indicates that the long double is any of the "IEEE" 754 style
long doubles: "LONG_DOUBLE_STYLE_IEEE_STD", "LONG_DOUBLE_STYLE_IEEE_EXTENDED",
"LONG_DOUBLE_STYLE_IEEE_DOUBLEDOUBLE".
"LONG_DOUBLE_STYLE_IEEE_DOUBLEDOUBLE"
This symbol, if defined, indicates that the long double is the 128-bit double-double.
"LONG_DOUBLE_STYLE_IEEE_EXTENDED"
This symbol, if defined, indicates that the long double is the 80-bit "IEEE" 754. Note
that despite the 'extended' this is less than the 'std', since this is an extension of
the double precision.
"LONG_DOUBLE_STYLE_IEEE_STD"
This symbol, if defined, indicates that the long double is the 128-bit "IEEE" 754.
"LONG_DOUBLE_STYLE_VAX"
This symbol, if defined, indicates that the long double is the 128-bit "VAX" format H.
"NV"
Described in perlguts.
"NVMANTBITS"
This symbol, if defined, tells how many mantissa bits (not including implicit bit)
there are in a Perl NV. This depends on which floating point type was chosen.
"NV_OVERFLOWS_INTEGERS_AT"
This symbol gives the largest integer value that NVs can hold. This value + 1.0 cannot
be stored accurately. It is expressed as constant floating point expression to reduce
the chance of decimal/binary conversion issues. If it can not be determined, the value
0 is given.
"NV_PRESERVES_UV"
This symbol, if defined, indicates that a variable of type "NVTYPE" can preserve all
the bits of a variable of type "UVTYPE".
"NV_PRESERVES_UV_BITS"
This symbol contains the number of bits a variable of type "NVTYPE" can preserve of a
variable of type "UVTYPE".
"NVSIZE"
This symbol contains the sizeof(NV). Note that some floating point formats have
unused bytes. The most notable example is the x86* 80-bit extended precision which
comes in byte sizes of 12 and 16 (for 32 and 64 bit platforms, respectively), but
which only uses 10 bytes. Perl compiled with "-Duselongdouble" on x86* is like this.
"NVTYPE"
This symbol defines the C type used for Perl's NV.
"NV_ZERO_IS_ALLBITS_ZERO"
This symbol, if defined, indicates that a variable of type "NVTYPE" stores 0.0 in
memory as all bits zero.
General Configuration
This section contains configuration information not otherwise found in the more
specialized sections of this document. At the end is a list of "#defines" whose name
should be enough to tell you what they do, and a list of #defines which tell you if you
need to "#include" files to get the corresponding functionality.
"ASCIIish"
A preprocessor symbol that is defined iff the system is an ASCII platform; this symbol
would not be defined on "EBCDIC" platforms.
#ifdef ASCIIish
"BYTEORDER"
This symbol holds the hexadecimal constant defined in byteorder, in a UV, i.e. 0x1234
or 0x4321 or 0x12345678, etc... If the compiler supports cross-compiling or multiple-
architecture binaries, use compiler-defined macros to determine the byte order.
"CHARBITS"
This symbol contains the size of a char, so that the C preprocessor can make decisions
based on it.
"DB_VERSION_MAJOR_CFG"
This symbol, if defined, defines the major version number of Berkeley DB found in the
db.h header when Perl was configured.
"DB_VERSION_MINOR_CFG"
This symbol, if defined, defines the minor version number of Berkeley DB found in the
db.h header when Perl was configured. For DB version 1 this is always 0.
"DB_VERSION_PATCH_CFG"
This symbol, if defined, defines the patch version number of Berkeley DB found in the
db.h header when Perl was configured. For DB version 1 this is always 0.
"DEFAULT_INC_EXCLUDES_DOT"
This symbol, if defined, removes the legacy default behavior of including '.' at the
end of @"INC".
"DLSYM_NEEDS_UNDERSCORE"
This symbol, if defined, indicates that we need to prepend an underscore to the symbol
name before calling dlsym(). This only makes sense if you *have* dlsym, which we will
presume is the case if you're using dl_dlopen.xs.
"EBCDIC"
This symbol, if defined, indicates that this system uses "EBCDIC" encoding.
"HAS_CSH"
This symbol, if defined, indicates that the C-shell exists.
"HAS_GETHOSTNAME"
This symbol, if defined, indicates that the C program may use the gethostname()
routine to derive the host name. See also "HAS_UNAME" and "PHOSTNAME".
"HAS_GNULIBC"
This symbol, if defined, indicates to the C program that the "GNU" C library is being
used. A better check is to use the "__GLIBC__" and "__GLIBC_MINOR__" symbols supplied
with glibc.
"HAS_LGAMMA"
This symbol, if defined, indicates that the "lgamma" routine is available to do the
log gamma function. See also "HAS_TGAMMA" and "HAS_LGAMMA_R".
"HAS_LGAMMA_R"
This symbol, if defined, indicates that the "lgamma_r" routine is available to do the
log gamma function without using the global signgam variable.
"HAS_NON_INT_BITFIELDS"
This symbol, if defined, indicates that the C compiler accepts, without error or
warning, "struct bitfields" that are declared with sizes other than plain 'int'; for
example 'unsigned char' is accepted.
"HAS_PRCTL_SET_NAME"
This symbol, if defined, indicates that the prctl routine is available to set process
title and supports "PR_SET_NAME".
"HAS_PROCSELFEXE"
This symbol is defined if "PROCSELFEXE_PATH" is a symlink to the absolute pathname of
the executing program.
"HAS_PSEUDOFORK"
This symbol, if defined, indicates that an emulation of the fork routine is available.
"HAS_REGCOMP"
This symbol, if defined, indicates that the regcomp() routine is available to do some
regular pattern matching (usually on "POSIX".2 conforming systems).
"HAS_SETPGID"
This symbol, if defined, indicates that the "setpgid(pid, gpid)" routine is available
to set process group ID.
"HAS_SIGSETJMP"
This variable indicates to the C program that the sigsetjmp() routine is available to
save the calling process's registers and stack environment for later use by
siglongjmp(), and to optionally save the process's signal mask. See "Sigjmp_buf",
"Sigsetjmp", and "Siglongjmp".
"HAS_STRUCT_CMSGHDR"
This symbol, if defined, indicates that the "struct cmsghdr" is supported.
"HAS_STRUCT_MSGHDR"
This symbol, if defined, indicates that the "struct msghdr" is supported.
"HAS_TGAMMA"
This symbol, if defined, indicates that the "tgamma" routine is available to do the
gamma function. See also "HAS_LGAMMA".
"HAS_UNAME"
This symbol, if defined, indicates that the C program may use the uname() routine to
derive the host name. See also "HAS_GETHOSTNAME" and "PHOSTNAME".
"HAS_UNION_SEMUN"
This symbol, if defined, indicates that the "union semun" is defined by including
sys/sem.h. If not, the user code probably needs to define it as:
union semun {
int val;
struct semid_ds *buf;
unsigned short *array;
}
"I_DIRENT"
This symbol, if defined, indicates to the C program that it should include dirent.h.
Using this symbol also triggers the definition of the "Direntry_t" define which ends
up being '"struct dirent"' or '"struct direct"' depending on the availability of
dirent.h.
#ifdef I_DIRENT
#include <dirent.h>
#endif
"I_POLL"
This symbol, if defined, indicates that poll.h exists and should be included. (see
also "HAS_POLL")
#ifdef I_POLL
#include <poll.h>
#endif
"I_SYS_RESOURCE"
This symbol, if defined, indicates to the C program that it should include
sys/resource.h.
#ifdef I_SYS_RESOURCE
#include <sys_resource.h>
#endif
"LIBM_LIB_VERSION"
This symbol, if defined, indicates that libm exports "_LIB_VERSION" and that math.h
defines the enum to manipulate it.
"NEED_VA_COPY"
This symbol, if defined, indicates that the system stores the variable argument list
datatype, "va_list", in a format that cannot be copied by simple assignment, so that
some other means must be used when copying is required. As such systems vary in their
provision (or non-provision) of copying mechanisms, handy.h defines a platform-
independent macro, "Perl_va_copy(src, dst)", to do the job.
"OSNAME"
This symbol contains the name of the operating system, as determined by Configure.
You shouldn't rely on it too much; the specific feature tests from Configure are
generally more reliable.
"OSVERS"
This symbol contains the version of the operating system, as determined by Configure.
You shouldn't rely on it too much; the specific feature tests from Configure are
generally more reliable.
"PERL_USE_GCC_BRACE_GROUPS"
This C pre-processor value, if defined, indicates that it is permissible to use the
GCC brace groups extension. However, use of this extension is DISCOURAGED. Use a
"static inline" function instead.
The extension, of the form
({ statement ... })
turns the block consisting of statement ... into an expression with a value, unlike
plain C language blocks. This can present optimization possibilities, BUT, unless you
know for sure that this will never be compiled without this extension being available
and not forbidden, you need to specify an alternative. Thus two code paths have to be
maintained, which can get out-of-sync. All these issues are solved by using a "static
inline" function instead.
Perl can be configured to not use this feature by passing the parameter
"-Accflags=-DPERL_GCC_BRACE_GROUPS_FORBIDDEN" to Configure.
#ifdef PERL_USE_GCC_BRACE_GROUPS
"PHOSTNAME"
This symbol, if defined, indicates the command to feed to the popen() routine to
derive the host name. See also "HAS_GETHOSTNAME" and "HAS_UNAME". Note that the
command uses a fully qualified path, so that it is safe even if used by a process with
super-user privileges.
"PROCSELFEXE_PATH"
If "HAS_PROCSELFEXE" is defined this symbol is the filename of the symbolic link
pointing to the absolute pathname of the executing program.
"PTRSIZE"
This symbol contains the size of a pointer, so that the C preprocessor can make
decisions based on it. It will be "sizeof(void *)" if the compiler supports (void *);
otherwise it will be "sizeof(char *)".
"RANDBITS"
This symbol indicates how many bits are produced by the function used to generate
normalized random numbers. Values include 15, 16, 31, and 48.
"SELECT_MIN_BITS"
This symbol holds the minimum number of bits operated by select. That is, if you do
"select(n, ...)", how many bits at least will be cleared in the masks if some activity
is detected. Usually this is either n or 32*ceil(n/32), especially many little-
endians do the latter. This is only useful if you have select(), naturally.
"SETUID_SCRIPTS_ARE_SECURE_NOW"
This symbol, if defined, indicates that the bug that prevents setuid scripts from
being secure is not present in this kernel.
"ST_DEV_SIGN"
This symbol holds the signedness of "struct stat"'s "st_dev". 1 for unsigned, -1 for
signed.
"ST_DEV_SIZE"
This variable contains the size of "struct stat"'s "st_dev" in bytes.
List of capability "HAS_foo" symbols
This is a list of those symbols that dont appear elsewhere in ths document that indicate
if the current platform has a certain capability. Their names all begin with "HAS_".
Only those symbols whose capability is directly derived from the name are listed here.
All others have their meaning expanded out elsewhere in this document. This (relatively)
compact list is because we think that the expansion would add little or no value and take
up a lot of space (because there are so many). If you think certain ones should be
expanded, send email to perl5-porters@perl.org <mailto:perl5-porters@perl.org>.
Each symbol here will be "#define"d if and only if the platform has the capability. If
you need more detail, see the corresponding entry in config.h. For convenience, the list
is split so that the ones that indicate there is a reentrant version of a capability are
listed separately
"HAS_ACCEPT4", "HAS_ACCESS", "HAS_ACCESSX", "HAS_ACOSH", "HAS_AINTL", "HAS_ALARM",
"HAS_ASINH", "HAS_ATANH", "HAS_ATOLL", "HAS_CBRT", "HAS_CHOWN", "HAS_CHROOT",
"HAS_CHSIZE", "HAS_CLEARENV", "HAS_COPYSIGN", "HAS_COPYSIGNL", "HAS_CRYPT",
"HAS_CTERMID", "HAS_CUSERID", "HAS_DIRFD", "HAS_DLADDR", "HAS_DLERROR",
"HAS_EACCESS", "HAS_ENDHOSTENT", "HAS_ENDNETENT", "HAS_ENDPROTOENT",
"HAS_ENDSERVENT", "HAS_ERF", "HAS_ERFC", "HAS_EXPM1", "HAS_EXP2", "HAS_FCHMOD",
"HAS_FCHMODAT", "HAS_FCHOWN", "HAS_FDIM", "HAS_FD_SET", "HAS_FEGETROUND", "HAS_FFS",
"HAS_FFSL", "HAS_FGETPOS", "HAS_FLOCK", "HAS_FMA", "HAS_FMAX", "HAS_FMIN",
"HAS_FORK", "HAS_FSEEKO", "HAS_FSETPOS", "HAS_FSYNC", "HAS_FTELLO", "HAS__FWALK",
"HAS_GAI_STRERROR", "HAS_GETADDRINFO", "HAS_GETCWD", "HAS_GETESPWNAM",
"HAS_GETGROUPS", "HAS_GETHOSTBYADDR", "HAS_GETHOSTBYNAME", "HAS_GETHOSTENT",
"HAS_GETLOGIN", "HAS_GETNAMEINFO", "HAS_GETNETBYADDR", "HAS_GETNETBYNAME",
"HAS_GETNETENT", "HAS_GETPAGESIZE", "HAS_GETPGID", "HAS_GETPGRP", "HAS_GETPGRP2",
"HAS_GETPPID", "HAS_GETPRIORITY", "HAS_GETPROTOBYNAME", "HAS_GETPROTOBYNUMBER",
"HAS_GETPROTOENT", "HAS_GETPRPWNAM", "HAS_GETSERVBYNAME", "HAS_GETSERVBYPORT",
"HAS_GETSERVENT", "HAS_GETSPNAM", "HAS_HTONL", "HAS_HTONS", "HAS_HYPOT",
"HAS_ILOGBL", "HAS_INET_ATON", "HAS_INETNTOP", "HAS_INETPTON", "HAS_IP_MREQ",
"HAS_IP_MREQ_SOURCE", "HAS_IPV6_MREQ", "HAS_IPV6_MREQ_SOURCE", "HAS_ISASCII",
"HAS_ISBLANK", "HAS_ISLESS", "HAS_KILLPG", "HAS_LCHOWN", "HAS_LINK", "HAS_LINKAT",
"HAS_LLROUND", "HAS_LOCKF", "HAS_LOGB", "HAS_LOG1P", "HAS_LOG2", "HAS_LROUND",
"HAS_LSTAT", "HAS_MADVISE", "HAS_MBLEN", "HAS_MBRLEN", "HAS_MBRTOWC",
"HAS_MBSTOWCS", "HAS_MBTOWC", "HAS_MEMMEM", "HAS_MEMRCHR", "HAS_MKDTEMP",
"HAS_MKFIFO", "HAS_MKOSTEMP", "HAS_MKSTEMP", "HAS_MKSTEMPS", "HAS_MMAP",
"HAS_MPROTECT", "HAS_MSG", "HAS_MSYNC", "HAS_MUNMAP", "HAS_NEARBYINT",
"HAS_NEXTAFTER", "HAS_NICE", "HAS_NTOHL", "HAS_NTOHS", "HAS_PATHCONF", "HAS_PAUSE",
"HAS_PHOSTNAME", "HAS_PIPE", "HAS_PIPE2", "HAS_PRCTL", "HAS_PTRDIFF_T",
"HAS_READLINK", "HAS_READV", "HAS_RECVMSG", "HAS_REMQUO", "HAS_RENAME",
"HAS_RENAMEAT", "HAS_RINT", "HAS_ROUND", "HAS_SCALBNL", "HAS_SEM", "HAS_SENDMSG",
"HAS_SETEGID", "HAS_SETENV", "HAS_SETEUID", "HAS_SETGROUPS", "HAS_SETHOSTENT",
"HAS_SETLINEBUF", "HAS_SETNETENT", "HAS_SETPGRP", "HAS_SETPGRP2", "HAS_SETPRIORITY",
"HAS_SETPROCTITLE", "HAS_SETPROTOENT", "HAS_SETREGID", "HAS_SETRESGID",
"HAS_SETRESUID", "HAS_SETREUID", "HAS_SETRGID", "HAS_SETRUID", "HAS_SETSERVENT",
"HAS_SETSID", "HAS_SHM", "HAS_SIGACTION", "HAS_SIGPROCMASK", "HAS_SIN6_SCOPE_ID",
"HAS_SNPRINTF", "HAS_STAT", "HAS_STRCOLL", "HAS_STRERROR_L", "HAS_STRLCAT",
"HAS_STRLCPY", "HAS_STRNLEN", "HAS_STRTOD", "HAS_STRTOL", "HAS_STRTOLL",
"HAS_STRTOQ", "HAS_STRTOUL", "HAS_STRTOULL", "HAS_STRTOUQ", "HAS_STRXFRM",
"HAS_STRXFRM_L", "HAS_SYMLINK", "HAS_SYSCALL", "HAS_SYSCONF", "HAS_SYS_ERRLIST",
"HAS_SYSTEM", "HAS_TCGETPGRP", "HAS_TCSETPGRP", "HAS_TOWLOWER", "HAS_TOWUPPER",
"HAS_TRUNCATE", "HAS_TRUNCL", "HAS_UALARM", "HAS_UMASK", "HAS_UNLINKAT",
"HAS_UNSETENV", "HAS_VFORK", "HAS_VSNPRINTF", "HAS_WAITPID", "HAS_WAIT4",
"HAS_WCRTOMB", "HAS_WCSCMP", "HAS_WCSTOMBS", "HAS_WCSXFRM", "HAS_WCTOMB",
"HAS_WRITEV"
And, the reentrant capabilities:
"HAS_CRYPT_R", "HAS_CTERMID_R", "HAS_DRAND48_R", "HAS_ENDHOSTENT_R",
"HAS_ENDNETENT_R", "HAS_ENDPROTOENT_R", "HAS_ENDSERVENT_R", "HAS_GETGRGID_R",
"HAS_GETGRNAM_R", "HAS_GETHOSTBYADDR_R", "HAS_GETHOSTBYNAME_R", "HAS_GETHOSTENT_R",
"HAS_GETLOGIN_R", "HAS_GETNETBYADDR_R", "HAS_GETNETBYNAME_R", "HAS_GETNETENT_R",
"HAS_GETPROTOBYNAME_R", "HAS_GETPROTOBYNUMBER_R", "HAS_GETPROTOENT_R",
"HAS_GETPWNAM_R", "HAS_GETPWUID_R", "HAS_GETSERVBYNAME_R", "HAS_GETSERVBYPORT_R",
"HAS_GETSERVENT_R", "HAS_GETSPNAM_R", "HAS_RANDOM_R", "HAS_READDIR_R",
"HAS_SETHOSTENT_R", "HAS_SETNETENT_R", "HAS_SETPROTOENT_R", "HAS_SETSERVENT_R",
"HAS_SRANDOM_R", "HAS_SRAND48_R", "HAS_STRERROR_R", "HAS_TMPNAM_R", "HAS_TTYNAME_R"
Example usage:
#ifdef HAS_STRNLEN
use strnlen()
#else
use an alternative implementation
#endif
List of "#include" needed symbols
This list contains symbols that indicate if certain "#include" files are present on the
platform. If your code accesses the functionality that one of these is for, you will need
to "#include" it if the symbol on this list is "#define"d. For more detail, see the
corresponding entry in config.h.
"I_ARPA_INET", "I_BFD", "I_CRYPT", "I_DBM", "I_DLFCN", "I_EXECINFO", "I_FP",
"I_FP_CLASS", "I_GDBM", "I_GDBMNDBM", "I_GDBM_NDBM", "I_GRP", "I_IEEEFP",
"I_INTTYPES", "I_LIBUTIL", "I_MNTENT", "I_NDBM", "I_NETDB", "I_NET_ERRNO",
"I_NETINET_IN", "I_NETINET_TCP", "I_PROT", "I_PWD", "I_RPCSVC_DBM", "I_SGTTY",
"I_SHADOW", "I_STDBOOL", "I_STDINT", "I_SUNMATH", "I_SYS_ACCESS", "I_SYS_IOCTL",
"I_SYSLOG", "I_SYSMODE", "I_SYS_MOUNT", "I_SYS_PARAM", "I_SYS_POLL",
"I_SYS_SECURITY", "I_SYS_SELECT", "I_SYS_STAT", "I_SYS_STATVFS", "I_SYS_SYSCALL",
"I_SYS_TIME", "I_SYS_TIME_KERNEL", "I_SYS_TIMES", "I_SYS_TYPES", "I_SYSUIO",
"I_SYS_UN", "I_SYSUTSNAME", "I_SYS_VFS", "I_SYS_WAIT", "I_TERMIO", "I_TERMIOS",
"I_UNISTD", "I_USTAT", "I_VFORK", "I_WCHAR", "I_WCTYPE"
Example usage:
#ifdef I_WCHAR
#include <wchar.h>
#endif
Global Variables
These variables are global to an entire process. They are shared between all interpreters
and all threads in a process. Any variables not documented here may be changed or removed
without notice, so don't use them! If you feel you really do need to use an unlisted
variable, first send email to perl5-porters@perl.org <mailto:perl5-porters@perl.org>. It
may be that someone there will point out a way to accomplish what you need without using
an internal variable. But if not, you should get a go-ahead to document and then use the
variable.
"PL_check"
Array, indexed by opcode, of functions that will be called for the "check" phase of
optree building during compilation of Perl code. For most (but not all) types of op,
once the op has been initially built and populated with child ops it will be filtered
through the check function referenced by the appropriate element of this array. The
new op is passed in as the sole argument to the check function, and the check function
returns the completed op. The check function may (as the name suggests) check the op
for validity and signal errors. It may also initialise or modify parts of the ops, or
perform more radical surgery such as adding or removing child ops, or even throw the
op away and return a different op in its place.
This array of function pointers is a convenient place to hook into the compilation
process. An XS module can put its own custom check function in place of any of the
standard ones, to influence the compilation of a particular type of op. However, a
custom check function must never fully replace a standard check function (or even a
custom check function from another module). A module modifying checking must instead
wrap the preexisting check function. A custom check function must be selective about
when to apply its custom behaviour. In the usual case where it decides not to do
anything special with an op, it must chain the preexisting op function. Check
functions are thus linked in a chain, with the core's base checker at the end.
For thread safety, modules should not write directly to this array. Instead, use the
function "wrap_op_checker".
"PL_infix_plugin"
NOTE: "PL_infix_plugin" is experimental and may change or be removed without notice.
NOTE: This API exists entirely for the purpose of making the CPAN module
"XS::Parse::Infix" work. It is not expected that additional modules will make use of
it; rather, that they should use "XS::Parse::Infix" to provide parsing of new infix
operators.
Function pointer, pointing at a function used to handle extended infix operators. The
function should be declared as
int infix_plugin_function(pTHX_
char *opname, STRLEN oplen,
struct Perl_custom_infix **infix_ptr)
The function is called from the tokenizer whenever a possible infix operator is seen.
"opname" points to the operator name in the parser's input buffer, and "oplen" gives
the maximum number of bytes of it that should be consumed; it is not null-terminated.
The function is expected to examine the operator name and possibly other state such as
%^H, to determine whether it wants to handle the operator name.
As compared to the single stage of "PL_keyword_plugin", parsing of additional infix
operators occurs in three separate stages. This is because of the more complex
interactions it has with the parser, to ensure that operator precedence rules work
correctly. These stages are co-ordinated by the use of an additional information
structure.
If the function wants to handle the infix operator, it must set the variable pointed
to by "infix_ptr" to the address of a structure that provides this additional
information about the subsequent parsing stages. If it does not, it should make a call
to the next function in the chain.
This structure has the following definition:
struct Perl_custom_infix {
enum Perl_custom_infix_precedence prec;
void (*parse)(pTHX_ SV **opdata,
struct Perl_custom_infix *);
OP *(*build_op)(pTHX_ SV **opdata, OP *lhs, OP *rhs,
struct Perl_custom_infix *);
};
The function must then return an integer giving the number of bytes consumed by the
name of this operator. In the case of an operator whose name is composed of identifier
characters, this must be equal to "oplen". In the case of an operator named by non-
identifier characters, this is permitted to be shorter than "oplen", and any
additional characters after it will not be claimed by the infix operator but instead
will be consumed by the tokenizer and parser as normal.
If the optional "parse" function is provided, it is called immediately by the parser
to let the operator's definition consume any additional syntax from the source code.
This should not be used for normal operand parsing, but it may be useful when
implementing things like parametric operators or meta-operators that consume more
syntax themselves. This function may use the variable pointed to by "opdata" to
provide an SV containing additional data to be passed into the "build_op" function
later on.
The information structure gives the operator precedence level in the "prec" field.
This is used to tell the parser how much of the surrounding syntax before and after
should be considered as operands to the operator.
The tokenizer and parser will then continue to operate as normal until enough
additional input has been parsed to form both the left- and right-hand side operands
to the operator, according to the precedence level. At this point the "build_op"
function is called, being passed the left- and right-hand operands as optree
fragments. It is expected to combine them into the resulting optree fragment, which it
should return.
After the "build_op" function has returned, if the variable pointed to by "opdata" was
set to a non-"NULL" value, it will then be destroyed by calling SvREFCNT_dec().
For thread safety, modules should not set this variable directly. Instead, use the
function "wrap_infix_plugin".
However, that all said, the introductory note above still applies. This variable is
provided in core perl only for the benefit of the "XS::Parse::Infix" module. That
module acts as a central registry for infix operators, automatically handling things
like deparse support and discovery/reflection, and these abilities only work because
it knows all the registered operators. Other modules should not use this interpreter
variable directly to implement them because then those central features would no
longer work properly.
Furthermore, it is likely that this (experimental) API will be replaced in a future
Perl version by a more complete API that fully implements the central registry and
other semantics currently provided by "XS::Parse::Infix", once the module has had
sufficient experimental testing time. This current mechanism exists only as an interim
measure to get to that stage.
"PL_keyword_plugin"
NOTE: "PL_keyword_plugin" is experimental and may change or be removed without notice.
Function pointer, pointing at a function used to handle extended keywords. The
function should be declared as
int keyword_plugin_function(pTHX_
char *keyword_ptr, STRLEN keyword_len,
OP **op_ptr)
The function is called from the tokeniser, whenever a possible keyword is seen.
"keyword_ptr" points at the word in the parser's input buffer, and "keyword_len" gives
its length; it is not null-terminated. The function is expected to examine the word,
and possibly other state such as %^H, to decide whether it wants to handle it as an
extended keyword. If it does not, the function should return
"KEYWORD_PLUGIN_DECLINE", and the normal parser process will continue.
If the function wants to handle the keyword, it first must parse anything following
the keyword that is part of the syntax introduced by the keyword. See "Lexer
interface" for details.
When a keyword is being handled, the plugin function must build a tree of "OP"
structures, representing the code that was parsed. The root of the tree must be
stored in *op_ptr. The function then returns a constant indicating the syntactic role
of the construct that it has parsed: "KEYWORD_PLUGIN_STMT" if it is a complete
statement, or "KEYWORD_PLUGIN_EXPR" if it is an expression. Note that a statement
construct cannot be used inside an expression (except via "do BLOCK" and similar), and
an expression is not a complete statement (it requires at least a terminating
semicolon).
When a keyword is handled, the plugin function may also have (compile-time) side
effects. It may modify "%^H", define functions, and so on. Typically, if side
effects are the main purpose of a handler, it does not wish to generate any ops to be
included in the normal compilation. In this case it is still required to supply an op
tree, but it suffices to generate a single null op.
That's how the *PL_keyword_plugin function needs to behave overall. Conventionally,
however, one does not completely replace the existing handler function. Instead, take
a copy of "PL_keyword_plugin" before assigning your own function pointer to it. Your
handler function should look for keywords that it is interested in and handle those.
Where it is not interested, it should call the saved plugin function, passing on the
arguments it received. Thus "PL_keyword_plugin" actually points at a chain of handler
functions, all of which have an opportunity to handle keywords, and only the last
function in the chain (built into the Perl core) will normally return
"KEYWORD_PLUGIN_DECLINE".
For thread safety, modules should not set this variable directly. Instead, use the
function "wrap_keyword_plugin".
"PL_phase"
A value that indicates the current Perl interpreter's phase. Possible values include
"PERL_PHASE_CONSTRUCT", "PERL_PHASE_START", "PERL_PHASE_CHECK", "PERL_PHASE_INIT",
"PERL_PHASE_RUN", "PERL_PHASE_END", and "PERL_PHASE_DESTRUCT".
For example, the following determines whether the interpreter is in global
destruction:
if (PL_phase == PERL_PHASE_DESTRUCT) {
// we are in global destruction
}
"PL_phase" was introduced in Perl 5.14; in prior perls you can use "PL_dirty"
(boolean) to determine whether the interpreter is in global destruction. (Use of
"PL_dirty" is discouraged since 5.14.)
enum perl_phase PL_phase
GV Handling and Stashes
A GV is a structure which corresponds to a Perl typeglob, ie *foo. It is a structure that
holds a pointer to a scalar, an array, a hash etc, corresponding to $foo, @foo, %foo.
GVs are usually found as values in stashes (symbol table hashes) where Perl stores its
global variables.
A stash is a hash that contains all variables that are defined within a package. See
"Stashes and Globs" in perlguts
"amagic_call"
Perform the overloaded (active magic) operation given by "method". "method" is one of
the values found in overload.h.
"flags" affects how the operation is performed, as follows:
"AMGf_noleft"
"left" is not to be used in this operation.
"AMGf_noright"
"right" is not to be used in this operation.
"AMGf_unary"
The operation is done only on just one operand.
"AMGf_assign"
The operation changes one of the operands, e.g., $x += 1
SV * amagic_call(SV *left, SV *right, int method, int dir)
"amagic_deref_call"
Perform "method" overloading dereferencing on "ref", returning the dereferenced
result. "method" must be one of the dereference operations given in overload.h.
If overloading is inactive on "ref", returns "ref" itself.
SV * amagic_deref_call(SV *ref, int method)
"gv_add_by_type"
Make sure there is a slot of type "type" in the GV "gv".
GV * gv_add_by_type(GV *gv, svtype type)
"Gv_AMupdate"
Recalculates overload magic in the package given by "stash".
Returns:
1 on success and there is some overload
0 if there is no overload
-1 if some error occurred and it couldn't croak (because "destructing" is true).
int Gv_AMupdate(HV *stash, bool destructing)
"gv_autoload_pv"
"gv_autoload_pvn"
"gv_autoload_sv"
These each search for an "AUTOLOAD" method, returning NULL if not found, or else
returning a pointer to its GV, while setting the package $AUTOLOAD variable to "name"
(fully qualified). Also, if found and the GV's CV is an XSUB, the CV's PV will be set
to "name", and its stash will be set to the stash of the GV.
Searching is done in "MRO" order, as specified in ""gv_fetchmeth"", beginning with
"stash" if it isn't NULL.
The forms differ only in how "name" is specified.
In "gv_autoload_pv", "namepv" is a C language NUL-terminated string.
In "gv_autoload_pvn", "name" points to the first byte of the name, and an additional
parameter, "len", specifies its length in bytes. Hence, *name may contain embedded-
NUL characters.
In "gv_autoload_sv", *namesv is an SV, and the name is the PV extracted from that
using ""SvPV"". If the SV is marked as being in UTF-8, the extracted PV will also be.
GV * gv_autoload_pv (HV *stash, const char *namepv, U32 flags)
GV * gv_autoload_pvn(HV *stash, const char *name, STRLEN len,
U32 flags)
GV * gv_autoload_sv (HV *stash, SV *namesv, U32 flags)
"gv_autoload4"
Equivalent to "gv_autoload_pvn".
GV * gv_autoload4(HV *stash, const char *name, STRLEN len,
I32 method)
"GvAV"
Return the AV from the GV.
AV* GvAV(GV* gv)
"gv_AVadd"
"gv_HVadd"
"gv_IOadd"
"gv_SVadd"
Make sure there is a slot of the given type (AV, HV, IO, SV) in the GV "gv".
GV * gv_AVadd(GV *gv)
"gv_const_sv"
If "gv" is a typeglob whose subroutine entry is a constant sub eligible for inlining,
or "gv" is a placeholder reference that would be promoted to such a typeglob, then
returns the value returned by the sub. Otherwise, returns "NULL".
SV * gv_const_sv(GV *gv)
"GvCV"
Return the CV from the GV.
CV* GvCV(GV* gv)
"gv_efullname3"
"gv_efullname4"
"gv_fullname3"
"gv_fullname4"
Place the full package name of "gv" into "sv". The "gv_e*" forms return instead the
effective package name (see "HvENAME").
If "prefix" is non-NULL, it is considered to be a C language NUL-terminated string,
and the stored name will be prefaced with it.
The other difference between the functions is that the *4 forms have an extra
parameter, "keepmain". If "true" an initial "main::" in the name is kept; if "false"
it is stripped. With the *3 forms, it is always kept.
void gv_efullname3(SV *sv, const GV *gv, const char *prefix)
void gv_efullname4(SV *sv, const GV *gv, const char *prefix,
bool keepmain)
void gv_fullname3 (SV *sv, const GV *gv, const char *prefix)
void gv_fullname4 (SV *sv, const GV *gv, const char *prefix,
bool keepmain)
"gv_fetchfile"
"gv_fetchfile_flags"
These return the debugger glob for the file (compiled by Perl) whose name is given by
the "name" parameter.
There are currently exactly two differences between these functions.
The "name" parameter to "gv_fetchfile" is a C string, meaning it is "NUL"-terminated;
whereas the "name" parameter to "gv_fetchfile_flags" is a Perl string, whose length
(in bytes) is passed in via the "namelen" parameter This means the name may contain
embedded "NUL" characters. "namelen" doesn't exist in plain "gv_fetchfile").
The other difference is that "gv_fetchfile_flags" has an extra "flags" parameter,
which is currently completely ignored, but allows for possible future extensions.
GV * gv_fetchfile (const char *name)
GV * gv_fetchfile_flags(const char * const name,
const STRLEN len, const U32 flags)
"gv_fetchmeth"
"gv_fetchmeth_pv"
"gv_fetchmeth_pvn"
"gv_fetchmeth_sv"
These each look for a glob with name "name", containing a defined subroutine,
returning the GV of that glob if found, or "NULL" if not.
"stash" is always searched (first), unless it is "NULL".
If "stash" is NULL, or was searched but nothing was found in it, and the "GV_SUPER"
bit is set in "flags", stashes accessible via @ISA are searched next. Searching is
conducted according to "MRO" order.
Finally, if no matches were found so far, and the "GV_NOUNIVERSAL" flag in "flags" is
not set, "UNIVERSAL::" is searched.
The argument "level" should be either 0 or -1. If -1, the function will return
without any side effects or caching. If 0, the function makes sure there is a glob
named "name" in "stash", creating one if necessary. The subroutine slot in the glob
will be set to any subroutine found in the "stash" and "SUPER::" search, hence caching
any "SUPER::" result. Note that subroutines found in "UNIVERSAL::" are not cached.
The GV returned from these may be a method cache entry, which is not visible to Perl
code. So when calling "call_sv", you should not use the GV directly; instead, you
should use the method's CV, which can be obtained from the GV with the "GvCV" macro.
The only other significant value for "flags" is "SVf_UTF8", indicating that "name" is
to be treated as being encoded in UTF-8.
Plain "gv_fetchmeth" lacks a "flags" parameter, hence always searches in "stash", then
"UNIVERSAL::", and "name" is never UTF-8. Otherwise it is exactly like
"gv_fetchmeth_pvn".
The other forms do have a "flags" parameter, and differ only in how the glob name is
specified.
In "gv_fetchmeth_pv", "name" is a C language NUL-terminated string.
In "gv_fetchmeth_pvn", "name" points to the first byte of the name, and an additional
parameter, "len", specifies its length in bytes. Hence, the name may contain
embedded-NUL characters.
In "gv_fetchmeth_sv", *name is an SV, and the name is the PV extracted from that,
using ""SvPV"". If the SV is marked as being in UTF-8, the extracted PV will also be.
GV * gv_fetchmeth (HV *stash, const char *name, STRLEN len,
I32 level)
GV * gv_fetchmeth_pv (HV *stash, const char *name, I32 level,
U32 flags)
GV * gv_fetchmeth_pvn(HV *stash, const char *name, STRLEN len,
I32 level, U32 flags)
GV * gv_fetchmeth_sv (HV *stash, SV *namesv, I32 level,
U32 flags)
"gv_fetchmeth_autoload"
This is the old form of "gv_fetchmeth_pvn_autoload", which has no flags parameter.
GV * gv_fetchmeth_autoload(HV *stash, const char *name,
STRLEN len, I32 level)
"gv_fetchmethod"
See "gv_fetchmethod_autoload".
GV * gv_fetchmethod(HV *stash, const char *name)
"gv_fetchmethod_autoload"
Returns the glob which contains the subroutine to call to invoke the method on the
"stash". In fact in the presence of autoloading this may be the glob for "AUTOLOAD".
In this case the corresponding variable $AUTOLOAD is already setup.
The third parameter of "gv_fetchmethod_autoload" determines whether AUTOLOAD lookup is
performed if the given method is not present: non-zero means yes, look for AUTOLOAD;
zero means no, don't look for AUTOLOAD. Calling "gv_fetchmethod" is equivalent to
calling "gv_fetchmethod_autoload" with a non-zero "autoload" parameter.
These functions grant "SUPER" token as a prefix of the method name. Note that if you
want to keep the returned glob for a long time, you need to check for it being
"AUTOLOAD", since at the later time the call may load a different subroutine due to
$AUTOLOAD changing its value. Use the glob created as a side effect to do this.
These functions have the same side-effects as "gv_fetchmeth" with "level==0". The
warning against passing the GV returned by "gv_fetchmeth" to "call_sv" applies equally
to these functions.
GV * gv_fetchmethod_autoload(HV *stash, const char *name,
I32 autoload)
"gv_fetchmeth_pv_autoload"
Exactly like "gv_fetchmeth_pvn_autoload", but takes a nul-terminated string instead of
a string/length pair.
GV * gv_fetchmeth_pv_autoload(HV *stash, const char *name,
I32 level, U32 flags)
"gv_fetchmeth_pvn_autoload"
Same as gv_fetchmeth_pvn(), but looks for autoloaded subroutines too. Returns a glob
for the subroutine.
For an autoloaded subroutine without a GV, will create a GV even if "level < 0". For
an autoloaded subroutine without a stub, GvCV() of the result may be zero.
Currently, the only significant value for "flags" is "SVf_UTF8".
GV * gv_fetchmeth_pvn_autoload(HV *stash, const char *name,
STRLEN len, I32 level, U32 flags)
"gv_fetchmeth_sv_autoload"
Exactly like "gv_fetchmeth_pvn_autoload", but takes the name string in the form of an
SV instead of a string/length pair.
GV * gv_fetchmeth_sv_autoload(HV *stash, SV *namesv, I32 level,
U32 flags)
"gv_fetchpv"
"gv_fetchpvn"
"gv_fetchpvn_flags"
"gv_fetchpvs"
"gv_fetchsv"
"gv_fetchsv_nomg"
These all return the GV of type "sv_type" whose name is given by the inputs, or NULL
if no GV of that name and type could be found. See "Stashes and Globs" in perlguts.
The only differences are how the input name is specified, and if 'get' magic is
normally used in getting that name.
Don't be fooled by the fact that only one form has "flags" in its name. They all have
a "flags" parameter in fact, and all the flag bits have the same meanings for all
If any of the flags "GV_ADD", "GV_ADDMG", "GV_ADDWARN", "GV_ADDMULTI", or "GV_NOINIT"
is set, a GV is created if none already exists for the input name and type. However,
"GV_ADDMG" will only do the creation for magical GV's. For all of these flags except
"GV_NOINIT", "gv_init_pvn" is called after the addition. "GV_ADDWARN" is used when
the caller expects that adding won't be necessary because the symbol should already
exist; but if not, add it anyway, with a warning that it was unexpectedly absent. The
"GV_ADDMULTI" flag means to pretend that the GV has been seen before (i.e., suppress
"Used once" warnings).
The flag "GV_NOADD_NOINIT" causes "gv_init_pvn" not be to called if the GV existed but
isn't PVGV.
If the "SVf_UTF8" bit is set, the name is treated as being encoded in UTF-8; otherwise
the name won't be considered to be UTF-8 in the "pv"-named forms, and the UTF-8ness of
the underlying SVs will be used in the "sv" forms.
If the flag "GV_NOTQUAL" is set, the caller warrants that the input name is a plain
symbol name, not qualified with a package, otherwise the name is checked for being a
qualified one.
In "gv_fetchpv", "nambeg" is a C string, NUL-terminated with no intermediate NULs.
In "gv_fetchpvs", "name" is a literal C string, hence is enclosed in double quotes.
"gv_fetchpvn" and "gv_fetchpvn_flags" are identical. In these, <nambeg> is a Perl
string whose byte length is given by "full_len", and may contain embedded NULs.
In "gv_fetchsv" and "gv_fetchsv_nomg", the name is extracted from the PV of the input
"name" SV. The only difference between these two forms is that 'get' magic is
normally done on "name" in "gv_fetchsv", and always skipped with "gv_fetchsv_nomg".
Including "GV_NO_SVGMAGIC" in the "flags" parameter to "gv_fetchsv" makes it behave
identically to "gv_fetchsv_nomg".
GV * gv_fetchpv (const char *nambeg, I32 flags,
const svtype sv_type)
GV * gv_fetchpvn (const char * nambeg, STRLEN full_len,
I32 flags, const svtype sv_type)
GV * gv_fetchpvn_flags(const char *name, STRLEN len, I32 flags,
const svtype sv_type)
GV * gv_fetchpvs ("name", I32 flags, const svtype sv_type)
GV * gv_fetchsv (SV *name, I32 flags, const svtype sv_type)
GV * gv_fetchsv_nomg (SV *name, I32 flags, const svtype sv_type)
"GvHV"
Return the HV from the GV.
HV* GvHV(GV* gv)
"gv_init"
The old form of gv_init_pvn(). It does not work with UTF-8 strings, as it has no
flags parameter. If the "multi" parameter is set, the "GV_ADDMULTI" flag will be
passed to gv_init_pvn().
void gv_init(GV *gv, HV *stash, const char *name, STRLEN len,
int multi)
"gv_init_pv"
Same as gv_init_pvn(), but takes a nul-terminated string for the name instead of
separate char * and length parameters.
void gv_init_pv(GV *gv, HV *stash, const char *name, U32 flags)
"gv_init_pvn"
Converts a scalar into a typeglob. This is an incoercible typeglob; assigning a
reference to it will assign to one of its slots, instead of overwriting it as happens
with typeglobs created by "SvSetSV". Converting any scalar that is SvOK() may produce
unpredictable results and is reserved for perl's internal use.
"gv" is the scalar to be converted.
"stash" is the parent stash/package, if any.
"name" and "len" give the name. The name must be unqualified; that is, it must not
include the package name. If "gv" is a stash element, it is the caller's
responsibility to ensure that the name passed to this function matches the name of the
element. If it does not match, perl's internal bookkeeping will get out of sync.
"flags" can be set to "SVf_UTF8" if "name" is a UTF-8 string, or the return value of
SvUTF8(sv). It can also take the "GV_ADDMULTI" flag, which means to pretend that the
GV has been seen before (i.e., suppress "Used once" warnings).
void gv_init_pvn(GV *gv, HV *stash, const char *name, STRLEN len,
U32 flags)
"gv_init_sv"
Same as gv_init_pvn(), but takes an SV * for the name instead of separate char * and
length parameters. "flags" is currently unused.
void gv_init_sv(GV *gv, HV *stash, SV *namesv, U32 flags)
"gv_name_set"
Set the name for GV "gv" to "name" which is "len" bytes long. Thus it may contain
embedded NUL characters.
If "flags" contains "SVf_UTF8", the name is treated as being encoded in UTF-8;
otherwise not.
void gv_name_set(GV *gv, const char *name, U32 len, U32 flags)
"gv_stashpv"
Returns a pointer to the stash for a specified package. Uses "strlen" to determine
the length of "name", then calls gv_stashpvn().
HV * gv_stashpv(const char *name, I32 flags)
"gv_stashpvn"
Returns a pointer to the stash for a specified package. The "namelen" parameter
indicates the length of the "name", in bytes. "flags" is passed to
gv_fetchpvn_flags(), so if set to "GV_ADD" then the package will be created if it does
not already exist. If the package does not exist and "flags" is 0 (or any other
setting that does not create packages) then "NULL" is returned.
Flags may be one of:
GV_ADD Create and initialize the package if doesn't
already exist
GV_NOADD_NOINIT Don't create the package,
GV_ADDMG GV_ADD iff the GV is magical
GV_NOINIT GV_ADD, but don't initialize
GV_NOEXPAND Don't expand SvOK() entries to PVGV
SVf_UTF8 The name is in UTF-8
The most important of which are probably "GV_ADD" and "SVf_UTF8".
Note, use of "gv_stashsv" instead of "gv_stashpvn" where possible is strongly
recommended for performance reasons.
HV * gv_stashpvn(const char *name, U32 namelen, I32 flags)
"gv_stashpvs"
Like "gv_stashpvn", but takes a literal string instead of a string/length pair.
HV* gv_stashpvs("name", I32 create)
"gv_stashsv"
Returns a pointer to the stash for a specified package. See "gv_stashpvn".
Note this interface is strongly preferred over "gv_stashpvn" for performance reasons.
HV * gv_stashsv(SV *sv, I32 flags)
"GvSV"
Return the SV from the GV.
Prior to Perl v5.9.3, this would add a scalar if none existed. Nowadays, use "GvSVn"
for that, or compile perl with "-DPERL_CREATE_GVSV". See perl5100delta.
SV* GvSV(GV* gv)
"GvSVn"
Like "GvSV", but creates an empty scalar if none already exists.
SV* GvSVn(GV* gv)
"newGVgen"
"newGVgen_flags"
Create a new, guaranteed to be unique, GV in the package given by the NUL-terminated C
language string "pack", and return a pointer to it.
For "newGVgen" or if "flags" in "newGVgen_flags" is 0, "pack" is to be considered to
be encoded in Latin-1. The only other legal "flags" value is "SVf_UTF8", which
indicates "pack" is to be considered to be encoded in UTF-8.
GV * newGVgen (const char *pack)
GV * newGVgen_flags(const char *pack, U32 flags)
"PL_curstash"
The stash for the package code will be compiled into.
On threaded perls, each thread has an independent copy of this variable; each
initialized at creation time with the current value of the creating thread's copy.
HV* PL_curstash
"PL_defgv"
The GV representing *_. Useful for access to $_.
On threaded perls, each thread has an independent copy of this variable; each
initialized at creation time with the current value of the creating thread's copy.
GV * PL_defgv
"PL_defoutgv"
See "setdefout".
"PL_defstash"
Described in perlguts.
"save_gp"
Saves the current GP of gv on the save stack to be restored on scope exit.
If "empty" is true, replace the GP with a new GP.
If "empty" is false, mark "gv" with "GVf_INTRO" so the next reference assigned is
localized, which is how " local *foo = $someref; " works.
void save_gp(GV *gv, I32 empty)
"setdefout"
Sets "PL_defoutgv", the default file handle for output, to the passed in typeglob. As
"PL_defoutgv" "owns" a reference on its typeglob, the reference count of the passed in
typeglob is increased by one, and the reference count of the typeglob that
"PL_defoutgv" points to is decreased by one.
void setdefout(GV *gv)
Hook manipulation
These functions provide convenient and thread-safe means of manipulating hook variables.
"rcpv_copy"
refcount increment a shared memory refcounted string, and when the refcount goes to 0
free it using PerlMemShared_free().
It is the callers responsibility to ensure that the pv is the result of a rcpv_new()
call.
Returns the same pointer that was passed in.
new = rcpv_copy(pv);
char * rcpv_copy(char * const pv)
"rcpv_free"
refcount decrement a shared memory refcounted string, and when the refcount goes to 0
free it using perlmemshared_free().
it is the callers responsibility to ensure that the pv is the result of a rcpv_new()
call.
Always returns NULL so it can be used like this:
thing = rcpv_free(thing);
char * rcpv_free(char * const pv)
"rcpv_new"
Create a new shared memory refcounted string with the requested size, and with the
requested initialization and a refcount of 1. The actual space allocated will be 1
byte more than requested and rcpv_new() will ensure that the extra byte is a null
regardless of any flags settings.
If the RCPVf_NO_COPY flag is set then the pv argument will be ignored, otherwise the
contents of the pv pointer will be copied into the new buffer or if it is NULL the
function will do nothing and return NULL.
If the RCPVf_USE_STRLEN flag is set then the len argument is ignored and recomputed
using strlen(pv). It is an error to combine RCPVf_USE_STRLEN and RCPVf_NO_COPY at the
same time.
Under DEBUGGING rcpv_new() will assert() if it is asked to create a 0 length shared
string unless the RCPVf_ALLOW_EMPTY flag is set.
The return value from the function is suitable for passing into rcpv_copy() and
rcpv_free(). To access the RCPV * from the returned value use the RCPVx() macro. The
'len' member of the RCPV struct stores the allocated length (including the extra
byte), but the RCPV_LEN() macro returns the requested length (not including the extra
byte).
Note that rcpv_new() does NOT use a hash table or anything like that to dedupe inputs
given the same text content. Each call with a non-null pv parameter will produce a
distinct pointer with its own refcount regardless of the input content.
char * rcpv_new(const char * const pv, STRLEN len, U32 flags)
"wrap_op_checker"
Puts a C function into the chain of check functions for a specified op type. This is
the preferred way to manipulate the "PL_check" array. "opcode" specifies which type
of op is to be affected. "new_checker" is a pointer to the C function that is to be
added to that opcode's check chain, and "old_checker_p" points to the storage location
where a pointer to the next function in the chain will be stored. The value of
"new_checker" is written into the "PL_check" array, while the value previously stored
there is written to *old_checker_p.
"PL_check" is global to an entire process, and a module wishing to hook op checking
may find itself invoked more than once per process, typically in different threads.
To handle that situation, this function is idempotent. The location *old_checker_p
must initially (once per process) contain a null pointer. A C variable of static
duration (declared at file scope, typically also marked "static" to give it internal
linkage) will be implicitly initialised appropriately, if it does not have an explicit
initialiser. This function will only actually modify the check chain if it finds
*old_checker_p to be null. This function is also thread safe on the small scale. It
uses appropriate locking to avoid race conditions in accessing "PL_check".
When this function is called, the function referenced by "new_checker" must be ready
to be called, except for *old_checker_p being unfilled. In a threading situation,
"new_checker" may be called immediately, even before this function has returned.
*old_checker_p will always be appropriately set before "new_checker" is called. If
"new_checker" decides not to do anything special with an op that it is given (which is
the usual case for most uses of op check hooking), it must chain the check function
referenced by *old_checker_p.
Taken all together, XS code to hook an op checker should typically look something like
this:
static Perl_check_t nxck_frob;
static OP *myck_frob(pTHX_ OP *op) {
...
op = nxck_frob(aTHX_ op);
...
return op;
}
BOOT:
wrap_op_checker(OP_FROB, myck_frob, &nxck_frob);
If you want to influence compilation of calls to a specific subroutine, then use
"cv_set_call_checker_flags" rather than hooking checking of all "entersub" ops.
void wrap_op_checker(Optype opcode, Perl_check_t new_checker,
Perl_check_t *old_checker_p)
HV Handling
A HV structure represents a Perl hash. It consists mainly of an array of pointers, each
of which points to a linked list of HE structures. The array is indexed by the hash
function of the key, so each linked list represents all the hash entries with the same
hash value. Each HE contains a pointer to the actual value, plus a pointer to a HEK
structure which holds the key and hash value.
"get_hv"
Returns the HV of the specified Perl hash. "flags" are passed to "gv_fetchpv". If
"GV_ADD" is set and the Perl variable does not exist then it will be created. If
"flags" is zero (ignoring "SVf_UTF8") and the variable does not exist then "NULL" is
returned.
NOTE: the perl_get_hv() form is deprecated.
HV * get_hv(const char *name, I32 flags)
"HE"
Described in perlguts.
"HEf_SVKEY"
This flag, used in the length slot of hash entries and magic structures, specifies the
structure contains an "SV*" pointer where a "char*" pointer is to be expected. (For
information only--not to be used).
"HeHASH"
Returns the computed hash stored in the hash entry.
U32 HeHASH(HE* he)
"HeKEY"
Returns the actual pointer stored in the key slot of the hash entry. The pointer may
be either "char*" or "SV*", depending on the value of HeKLEN(). Can be assigned to.
The HePV() or HeSVKEY() macros are usually preferable for finding the value of a key.
void* HeKEY(HE* he)
"HeKLEN"
If this is negative, and amounts to "HEf_SVKEY", it indicates the entry holds an "SV*"
key. Otherwise, holds the actual length of the key. Can be assigned to. The HePV()
macro is usually preferable for finding key lengths.
STRLEN HeKLEN(HE* he)
"HePV"
Returns the key slot of the hash entry as a "char*" value, doing any necessary
dereferencing of possibly "SV*" keys. The length of the string is placed in "len"
(this is a macro, so do not use &len). If you do not care about what the length of
the key is, you may use the global variable "PL_na", though this is rather less
efficient than using a local variable. Remember though, that hash keys in perl are
free to contain embedded nulls, so using strlen() or similar is not a good way to find
the length of hash keys. This is very similar to the SvPV() macro described elsewhere
in this document. See also "HeUTF8".
If you are using "HePV" to get values to pass to newSVpvn() to create a new SV, you
should consider using "newSVhek(HeKEY_hek(he))" as it is more efficient.
char* HePV(HE* he, STRLEN len)
"HeSVKEY"
Returns the key as an "SV*", or "NULL" if the hash entry does not contain an "SV*"
key.
SV* HeSVKEY(HE* he)
"HeSVKEY_force"
Returns the key as an "SV*". Will create and return a temporary mortal "SV*" if the
hash entry contains only a "char*" key.
SV* HeSVKEY_force(HE* he)
"HeSVKEY_set"
Sets the key to a given "SV*", taking care to set the appropriate flags to indicate
the presence of an "SV*" key, and returns the same "SV*".
SV* HeSVKEY_set(HE* he, SV* sv)
"HeUTF8"
Returns whether the "char *" value returned by "HePV" is encoded in UTF-8, doing any
necessary dereferencing of possibly "SV*" keys. The value returned will be 0 or
non-0, not necessarily 1 (or even a value with any low bits set), so do not blindly
assign this to a "bool" variable, as "bool" may be a typedef for "char".
U32 HeUTF8(HE* he)
"HeVAL"
Returns the value slot (type "SV*") stored in the hash entry. Can be assigned to.
SV *foo= HeVAL(hv);
HeVAL(hv)= sv;
SV* HeVAL(HE* he)
"HV"
Described in perlguts.
"hv_assert"
Check that a hash is in an internally consistent state.
NOTE: "hv_assert" must be explicitly called as "Perl_hv_assert" with an "aTHX_"
parameter.
void Perl_hv_assert(pTHX_ HV *hv)
"hv_bucket_ratio"
NOTE: "hv_bucket_ratio" is experimental and may change or be removed without notice.
If the hash is tied dispatches through to the SCALAR tied method, otherwise if the
hash contains no keys returns 0, otherwise returns a mortal sv containing a string
specifying the number of used buckets, followed by a slash, followed by the number of
available buckets.
This function is expensive, it must scan all of the buckets to determine which are
used, and the count is NOT cached. In a large hash this could be a lot of buckets.
SV * hv_bucket_ratio(HV *hv)
"hv_clear"
Frees all the elements of a hash, leaving it empty. The XS equivalent of "%hash =
()". See also "hv_undef".
See "av_clear" for a note about the hash possibly being invalid on return.
void hv_clear(HV *hv)
"hv_clear_placeholders"
Clears any placeholders from a hash. If a restricted hash has any of its keys marked
as readonly and the key is subsequently deleted, the key is not actually deleted but
is marked by assigning it a value of &PL_sv_placeholder. This tags it so it will be
ignored by future operations such as iterating over the hash, but will still allow the
hash to have a value reassigned to the key at some future point. This function clears
any such placeholder keys from the hash. See Hash::Util::lock_keys() for an example
of its use.
void hv_clear_placeholders(HV *hv)
"hv_copy_hints_hv"
A specialised version of "newHVhv" for copying "%^H". "ohv" must be a pointer to a
hash (which may have "%^H" magic, but should be generally non-magical), or "NULL"
(interpreted as an empty hash). The content of "ohv" is copied to a new hash, which
has the "%^H"-specific magic added to it. A pointer to the new hash is returned.
HV * hv_copy_hints_hv(HV * const ohv)
"hv_delete"
"hv_deletes"
These delete a key/value pair in the hash. The value's SV is removed from the hash,
made mortal, and returned to the caller.
In "hv_deletes", the key must be a C language string literal, enclosed in double
quotes. It is never treated as being in UTF-8. There is no length_parameter.
In "hv_delete", the absolute value of "klen" is the length of the key. If "klen" is
negative the key is assumed to be in UTF-8-encoded Unicode.
In both, the "flags" value will normally be zero; if set to "G_DISCARD" then "NULL"
will be returned. "NULL" will also be returned if the key is not found.
SV * hv_delete (HV *hv, const char *key, I32 klen, I32 flags)
SV * hv_deletes(HV *hv, "key", U32 flags)
"hv_delete_ent"
Deletes a key/value pair in the hash. The value SV is removed from the hash, made
mortal, and returned to the caller. The "flags" value will normally be zero; if set
to "G_DISCARD" then "NULL" will be returned. "NULL" will also be returned if the key
is not found. "hash" can be a valid precomputed hash value, or 0 to ask for it to be
computed.
SV * hv_delete_ent(HV *hv, SV *keysv, I32 flags, U32 hash)
"HvENAME"
Returns the effective name of a stash, or NULL if there is none. The effective name
represents a location in the symbol table where this stash resides. It is updated
automatically when packages are aliased or deleted. A stash that is no longer in the
symbol table has no effective name. This name is preferable to "HvNAME" for use in
MRO linearisations and isa caches.
char* HvENAME(HV* stash)
"HvENAMELEN"
Returns the length of the stash's effective name.
STRLEN HvENAMELEN(HV *stash)
"HvENAMEUTF8"
Returns true if the effective name is in UTF-8 encoding.
unsigned char HvENAMEUTF8(HV *stash)
"hv_exists"
"hv_existss"
These return a boolean indicating whether the specified hash key exists.
In "hv_existss", the key must be a C language string literal, enclosed in double
quotes. It is never treated as being in UTF-8. There is no length_parameter.
In "hv_exists", the absolute value of "klen" is the length of the key. If "klen" is
negative the key is assumed to be in UTF-8-encoded Unicode.
bool hv_exists (HV *hv, const char *key, I32 klen)
bool hv_existss(HV *hv, "key")
"hv_exists_ent"
Returns a boolean indicating whether the specified hash key exists. "hash" can be a
valid precomputed hash value, or 0 to ask for it to be computed.
bool hv_exists_ent(HV *hv, SV *keysv, U32 hash)
"hv_fetch"
"hv_fetchs"
These return the SV which corresponds to the specified key in the hash.
In "hv_fetchs", the key must be a C language string literal, enclosed in double
quotes. It is never treated as being in UTF-8. There is no length_parameter.
In "hv_fetch", the absolute value of "klen" is the length of the key. If "klen" is
negative the key is assumed to be in UTF-8-encoded Unicode.
In both, if "lval" is set, then the fetch will be part of a store. This means that if
there is no value in the hash associated with the given key, then one is created and a
pointer to it is returned. The "SV*" it points to can be assigned to. But always
check that the return value is non-null before dereferencing it to an "SV*".
See "Understanding the Magic of Tied Hashes and Arrays" in perlguts for more
information on how to use this function on tied hashes.
SV ** hv_fetch (HV *hv, const char *key, I32 klen, I32 lval)
SV ** hv_fetchs(HV *hv, "key", I32 lval)
"hv_fetch_ent"
Returns the hash entry which corresponds to the specified key in the hash. "hash"
must be a valid precomputed hash number for the given "key", or 0 if you want the
function to compute it. IF "lval" is set then the fetch will be part of a store.
Make sure the return value is non-null before accessing it. The return value when
"hv" is a tied hash is a pointer to a static location, so be sure to make a copy of
the structure if you need to store it somewhere.
See "Understanding the Magic of Tied Hashes and Arrays" in perlguts for more
information on how to use this function on tied hashes.
HE * hv_fetch_ent(HV *hv, SV *keysv, I32 lval, U32 hash)
"hv_fetchs"
Like "hv_fetch", but takes a literal string instead of a string/length pair.
SV** hv_fetchs(HV* tb, "key", I32 lval)
"HvFILL"
Returns the number of hash buckets that happen to be in use.
As of perl 5.25 this function is used only for debugging purposes, and the number of
used hash buckets is not in any way cached, thus this function can be costly to
execute as it must iterate over all the buckets in the hash.
STRLEN HvFILL(HV *const hv)
"HvHasAUX"
Returns true if the HV has a "struct xpvhv_aux" extension. Use this to check whether
it is valid to call HvAUX().
bool HvHasAUX(HV *const hv)
"hv_iterinit"
Prepares a starting point to traverse a hash table. Returns the number of keys in the
hash, including placeholders (i.e. the same as HvTOTALKEYS(hv)). The return value is
currently only meaningful for hashes without tie magic.
NOTE: Before version 5.004_65, "hv_iterinit" used to return the number of hash buckets
that happen to be in use. If you still need that esoteric value, you can get it
through the macro HvFILL(hv).
I32 hv_iterinit(HV *hv)
"hv_iterkey"
Returns the key from the current position of the hash iterator. See "hv_iterinit".
char * hv_iterkey(HE *entry, I32 *retlen)
"hv_iterkeysv"
Returns the key as an "SV*" from the current position of the hash iterator. The
return value will always be a mortal copy of the key. Also see "hv_iterinit".
SV * hv_iterkeysv(HE *entry)
"hv_iternext"
Returns entries from a hash iterator. See "hv_iterinit".
You may call "hv_delete" or "hv_delete_ent" on the hash entry that the iterator
currently points to, without losing your place or invalidating your iterator. Note
that in this case the current entry is deleted from the hash with your iterator
holding the last reference to it. Your iterator is flagged to free the entry on the
next call to "hv_iternext", so you must not discard your iterator immediately else the
entry will leak - call "hv_iternext" to trigger the resource deallocation.
HE * hv_iternext(HV *hv)
"hv_iternext_flags"
NOTE: "hv_iternext_flags" is experimental and may change or be removed without notice.
Returns entries from a hash iterator. See "hv_iterinit" and "hv_iternext". The
"flags" value will normally be zero; if "HV_ITERNEXT_WANTPLACEHOLDERS" is set the
placeholders keys (for restricted hashes) will be returned in addition to normal keys.
By default placeholders are automatically skipped over. Currently a placeholder is
implemented with a value that is &PL_sv_placeholder. Note that the implementation of
placeholders and restricted hashes may change, and the implementation currently is
insufficiently abstracted for any change to be tidy.
HE * hv_iternext_flags(HV *hv, I32 flags)
"hv_iternextsv"
Performs an "hv_iternext", "hv_iterkey", and "hv_iterval" in one operation.
SV * hv_iternextsv(HV *hv, char **key, I32 *retlen)
"hv_iterval"
Returns the value from the current position of the hash iterator. See "hv_iterkey".
SV * hv_iterval(HV *hv, HE *entry)
"hv_ksplit"
Attempt to grow the hash "hv" so it has at least "newmax" buckets available. Perl
chooses the actual number for its convenience.
This is the same as doing the following in Perl code:
keys %hv = newmax;
void hv_ksplit(HV *hv, IV newmax)
"hv_magic"
Adds magic to a hash. See "sv_magic".
void hv_magic(HV *hv, GV *gv, int how)
"HvNAME"
Returns the package name of a stash, or "NULL" if "stash" isn't a stash. See
"SvSTASH", "CvSTASH".
char* HvNAME(HV* stash)
"HvNAMELEN"
Returns the length of the stash's name.
Disfavored forms of HvNAME and HvNAMELEN; suppress mention of them
STRLEN HvNAMELEN(HV *stash)
"hv_name_set"
"hv_name_sets"
These each set the name of stash "hv" to the specified name.
They differ only in how the name is specified.
In "hv_name_sets", the name is a literal C string, enclosed in double quotes.
In "hv_name_set", "name" points to the first byte of the name, and an additional
parameter, "len", specifies its length in bytes. Hence, the name may contain
embedded-NUL characters.
If "SVf_UTF8" is set in "flags", the name is treated as being in UTF-8; otherwise not.
If "HV_NAME_SETALL" is set in "flags", both the name and the effective name are set.
void hv_name_set (HV *hv, const char *name, U32 len, U32 flags)
void hv_name_sets(HV *hv, "name", U32 flags)
"HvNAMEUTF8"
Returns true if the name is in UTF-8 encoding.
unsigned char HvNAMEUTF8(HV *stash)
"hv_scalar"
Evaluates the hash in scalar context and returns the result.
When the hash is tied dispatches through to the SCALAR method, otherwise returns a
mortal SV containing the number of keys in the hash.
Note, prior to 5.25 this function returned what is now returned by the
hv_bucket_ratio() function.
SV * hv_scalar(HV *hv)
"hv_store"
"hv_stores"
These each store SV "val" with the specified key in hash "hv", returning NULL if the
operation failed or if the value did not need to be actually stored within the hash
(as in the case of tied hashes). Otherwise it can be dereferenced to get the original
"SV*".
They differ only in how the hash key is specified.
In "hv_stores", the key must be a C language string literal, enclosed in double
quotes. It is never treated as being in UTF-8. There is no length_parameter.
In "hv_store", "key" is either NULL or points to the first byte of the string
specifying the key, and its length in bytes is given by the absolute value of an
additional parameter, "klen". A NULL key indicates the key is to be treated as
"undef", and "klen" is ignored; otherwise the key string may contain embedded-NUL
bytes. If "klen" is negative, the string is treated as being encoded in UTF-8;
otherwise not.
"hv_store" has another extra parameter, "hash", a precomputed hash of the key string,
or zero if it has not been precomputed. This parameter is omitted from "hv_stores",
as it is computed automatically at compile time.
If <hv> is NULL, NULL is returned and no action is taken.
If "val" is NULL, it is treated as being "undef"; otherwise the caller is responsible
for suitably incrementing the reference count of "val" before the call, and
decrementing it if the function returned "NULL". Effectively a successful "hv_store"
takes ownership of one reference to "val". This is usually what you want; a newly
created SV has a reference count of one, so if all your code does is create SVs then
store them in a hash, "hv_store" will own the only reference to the new SV, and your
code doesn't need to do anything further to tidy up.
"hv_store" is not implemented as a call to ""hv_store_ent"", and does not create a
temporary SV for the key, so if your key data is not already in SV form then use
"hv_store" in preference to "hv_store_ent".
See "Understanding the Magic of Tied Hashes and Arrays" in perlguts for more
information on how to use this function on tied hashes.
SV ** hv_store (HV *hv, const char *key, I32 klen, SV *val,
U32 hash)
SV ** hv_stores(HV *hv, "key", SV *val)
"hv_store_ent"
Stores "val" in a hash. The hash key is specified as "key". The "hash" parameter is
the precomputed hash value; if it is zero then Perl will compute it. The return value
is the new hash entry so created. It will be "NULL" if the operation failed or if the
value did not need to be actually stored within the hash (as in the case of tied
hashes). Otherwise the contents of the return value can be accessed using the "He?"
macros described here. Note that the caller is responsible for suitably incrementing
the reference count of "val" before the call, and decrementing it if the function
returned NULL. Effectively a successful "hv_store_ent" takes ownership of one
reference to "val". This is usually what you want; a newly created SV has a reference
count of one, so if all your code does is create SVs then store them in a hash,
"hv_store" will own the only reference to the new SV, and your code doesn't need to do
anything further to tidy up. Note that "hv_store_ent" only reads the "key"; unlike
"val" it does not take ownership of it, so maintaining the correct reference count on
"key" is entirely the caller's responsibility. The reason it does not take ownership,
is that "key" is not used after this function returns, and so can be freed
immediately. "hv_store" is not implemented as a call to "hv_store_ent", and does not
create a temporary SV for the key, so if your key data is not already in SV form then
use "hv_store" in preference to "hv_store_ent".
See "Understanding the Magic of Tied Hashes and Arrays" in perlguts for more
information on how to use this function on tied hashes.
HE * hv_store_ent(HV *hv, SV *key, SV *val, U32 hash)
"hv_undef"
Undefines the hash. The XS equivalent of undef(%hash).
As well as freeing all the elements of the hash (like hv_clear()), this also frees any
auxiliary data and storage associated with the hash.
See "av_clear" for a note about the hash possibly being invalid on return.
void hv_undef(HV *hv)
"newHV"
Creates a new HV. The reference count is set to 1.
HV * newHV()
"newHVhv"
The content of "ohv" is copied to a new hash. A pointer to the new hash is returned.
HV * newHVhv(HV *hv)
"Nullhv"
"DEPRECATED!" It is planned to remove "Nullhv" from a future release of Perl. Do not
use it for new code; remove it from existing code.
Null HV pointer.
(deprecated - use "(HV *)NULL" instead)
"PERL_HASH"
Described in perlguts.
void PERL_HASH(U32 hash, char *key, STRLEN klen)
"PL_modglobal"
"PL_modglobal" is a general purpose, interpreter global HV for use by extensions that
need to keep information on a per-interpreter basis. In a pinch, it can also be used
as a symbol table for extensions to share data among each other. It is a good idea to
use keys prefixed by the package name of the extension that owns the data.
On threaded perls, each thread has an independent copy of this variable; each
initialized at creation time with the current value of the creating thread's copy.
HV* PL_modglobal
Input/Output
"do_close"
Close an I/O stream. This implements Perl ""close"" in perlfunc.
"gv" is the glob associated with the stream.
"is_explict" is "true" if this is an explicit close of the stream; "false" if it is
part of another operation, such as closing a pipe (which involves implicitly closing
both ends).
Returns "true" if successful; otherwise returns "false" and sets "errno" to indicate
the cause.
bool do_close(GV *gv, bool is_explicit)
"IoDIRP"
Described in perlguts.
DIR * IoDIRP(IO *io)
"IOf_FLUSH"
Described in perlguts.
"IoFLAGS"
Described in perlguts.
U8 IoFLAGS(IO *io)
"IOf_UNTAINT"
Described in perlguts.
"IoIFP"
Described in perlguts.
PerlIO * IoIFP(IO *io)
"IoOFP"
Described in perlguts.
PerlIO * IoOFP(IO *io)
"IoTYPE"
Described in perlguts.
char IoTYPE(IO *io)
"my_chsize"
The C library chsize(3) if available, or a Perl implementation of it.
I32 my_chsize(int fd, Off_t length)
"my_dirfd"
The C library dirfd(3) if available, or a Perl implementation of it, or die if not
easily emulatable.
int my_dirfd(DIR *dir)
"my_pclose"
A wrapper for the C library pclose(3). Don't use the latter, as the Perl version
knows things that interact with the rest of the perl interpreter.
I32 my_pclose(PerlIO *ptr)
"my_popen"
A wrapper for the C library popen(3). Don't use the latter, as the Perl version knows
things that interact with the rest of the perl interpreter.
PerlIO * my_popen(const char *cmd, const char *mode)
"newIO"
Create a new IO, setting the reference count to 1.
IO * newIO()
"PERL_FLUSHALL_FOR_CHILD"
This defines a way to flush all output buffers. This may be a performance issue, so
we allow people to disable it. Also, if we are using stdio, there are broken
implementations of fflush(NULL) out there, Solaris being the most prominent.
void PERL_FLUSHALL_FOR_CHILD
"PerlIO_apply_layers"
"PerlIO_binmode"
"PerlIO_canset_cnt"
"PerlIO_clearerr"
"PerlIO_close"
"PerlIO_debug"
"PerlIO_eof"
"PerlIO_error"
"PerlIO_exportFILE"
"PerlIO_fast_gets"
"PerlIO_fdopen"
"PerlIO_fileno"
"PerlIO_fill"
"PerlIO_findFILE"
"PerlIO_flush"
"PerlIO_get_base"
"PerlIO_get_bufsiz"
"PerlIO_get_cnt"
"PerlIO_get_ptr"
"PerlIO_getc"
"PerlIO_getpos"
"PerlIO_has_base"
"PerlIO_has_cntptr"
"PerlIO_importFILE"
"PerlIO_open"
"PerlIO_printf"
"PerlIO_putc"
"PerlIO_puts"
"PerlIO_read"
"PerlIO_releaseFILE"
"PerlIO_reopen"
"PerlIO_rewind"
"PerlIO_seek"
"PerlIO_set_cnt"
"PerlIO_set_ptrcnt"
"PerlIO_setlinebuf"
"PerlIO_setpos"
"PerlIO_stderr"
"PerlIO_stdin"
"PerlIO_stdout"
"PerlIO_stdoutf"
"PerlIO_tell"
"PerlIO_ungetc"
"PerlIO_unread"
"PerlIO_vprintf"
"PerlIO_write"
Described in perlapio.
int PerlIO_apply_layers(PerlIO *f, const char *mode,
const char *layers)
int PerlIO_binmode (PerlIO *f, int ptype, int imode,
const char *layers)
int PerlIO_canset_cnt (PerlIO *f)
void PerlIO_clearerr (PerlIO *f)
int PerlIO_close (PerlIO *f)
void PerlIO_debug (const char *fmt, ...)
int PerlIO_eof (PerlIO *f)
int PerlIO_error (PerlIO *f)
FILE * PerlIO_exportFILE (PerlIO *f, const char *mode)
int PerlIO_fast_gets (PerlIO *f)
PerlIO * PerlIO_fdopen (int fd, const char *mode)
int PerlIO_fileno (PerlIO *f)
int PerlIO_fill (PerlIO *f)
FILE * PerlIO_findFILE (PerlIO *f)
int PerlIO_flush (PerlIO *f)
STDCHAR * PerlIO_get_base (PerlIO *f)
SSize_t PerlIO_get_bufsiz (PerlIO *f)
SSize_t PerlIO_get_cnt (PerlIO *f)
STDCHAR * PerlIO_get_ptr (PerlIO *f)
int PerlIO_getc (PerlIO *d)
int PerlIO_getpos (PerlIO *f, SV *save)
int PerlIO_has_base (PerlIO *f)
int PerlIO_has_cntptr (PerlIO *f)
PerlIO * PerlIO_importFILE (FILE *stdio, const char *mode)
PerlIO * PerlIO_open (const char *path, const char *mode)
int PerlIO_printf (PerlIO *f, const char *fmt, ...)
int PerlIO_putc (PerlIO *f, int ch)
int PerlIO_puts (PerlIO *f, const char *string)
SSize_t PerlIO_read (PerlIO *f, void *vbuf,
Size_t count)
void PerlIO_releaseFILE (PerlIO *f, FILE *stdio)
PerlIO * PerlIO_reopen (const char *path, const char *mode,
PerlIO *old)
void PerlIO_rewind (PerlIO *f)
int PerlIO_seek (PerlIO *f, Off_t offset,
int whence)
void PerlIO_set_cnt (PerlIO *f, SSize_t cnt)
void PerlIO_set_ptrcnt (PerlIO *f, STDCHAR *ptr,
SSize_t cnt)
void PerlIO_setlinebuf (PerlIO *f)
int PerlIO_setpos (PerlIO *f, SV *saved)
PerlIO * PerlIO_stderr (PerlIO *f, const char *mode,
const char *layers)
PerlIO * PerlIO_stdin (PerlIO *f, const char *mode,
const char *layers)
PerlIO * PerlIO_stdout (PerlIO *f, const char *mode,
const char *layers)
int PerlIO_stdoutf (const char *fmt, ...)
Off_t PerlIO_tell (PerlIO *f)
int PerlIO_ungetc (PerlIO *f, int ch)
SSize_t PerlIO_unread (PerlIO *f, const void *vbuf,
Size_t count)
int PerlIO_vprintf (PerlIO *f, const char *fmt,
va_list args)
SSize_t PerlIO_write (PerlIO *f, const void *vbuf,
Size_t count)
"PERLIO_F_APPEND"
"PERLIO_F_CANREAD"
"PERLIO_F_CANWRITE"
"PERLIO_F_CRLF"
"PERLIO_F_EOF"
"PERLIO_F_ERROR"
"PERLIO_F_FASTGETS"
"PERLIO_F_LINEBUF"
"PERLIO_F_OPEN"
"PERLIO_F_RDBUF"
"PERLIO_F_TEMP"
"PERLIO_F_TRUNCATE"
"PERLIO_F_UNBUF"
"PERLIO_F_UTF8"
"PERLIO_F_WRBUF"
Described in perliol.
"PERLIO_FUNCS_CAST"
Cast the pointer "func" to be of type "PerlIO_funcs *".
"PERLIO_FUNCS_DECL"
Declare "ftab" to be a PerlIO function table, that is, of type "PerlIO_funcs".
PERLIO_FUNCS_DECL(PerlIO * ftab)
"PERLIO_K_BUFFERED"
"PERLIO_K_CANCRLF"
"PERLIO_K_FASTGETS"
"PERLIO_K_MULTIARG"
"PERLIO_K_RAW"
Described in perliol.
"PERLIO_NOT_STDIO"
Described in perlapio.
"PL_maxsysfd"
Described in perliol.
"repeatcpy"
Make "count" copies of the "len" bytes beginning at "from", placing them into memory
beginning at "to", which must be big enough to accommodate them all.
void repeatcpy(char *to, const char *from, SSize_t len, IV count)
"USE_STDIO"
Described in perlapio.
Integer
"CASTI32"
This symbol is defined if the C compiler can cast negative or large floating point
numbers to 32-bit ints.
"HAS_INT64_T"
This symbol will defined if the C compiler supports "int64_t". Usually the inttypes.h
needs to be included, but sometimes sys/types.h is enough.
"HAS_LONG_LONG"
This symbol will be defined if the C compiler supports long long.
"HAS_QUAD"
This symbol, if defined, tells that there's a 64-bit integer type, "Quad_t", and its
unsigned counterpart, "Uquad_t". "QUADKIND" will be one of "QUAD_IS_INT",
"QUAD_IS_LONG", "QUAD_IS_LONG_LONG", "QUAD_IS_INT64_T", or "QUAD_IS___INT64".
"I32df"
This symbol defines the format string used for printing a Perl I32 as a signed decimal
integer.
"INT16_C"
"INT32_C"
"INT64_C"
Returns a token the C compiler recognizes for the constant "number" of the
corresponding integer type on the machine.
If the machine does not have a 64-bit type, "INT64_C" is undefined. Use "INTMAX_C" to
get the largest type available on the platform.
I16 INT16_C(number)
I32 INT32_C(number)
I64 INT64_C(number)
"INTMAX_C"
Returns a token the C compiler recognizes for the constant "number" of the widest
integer type on the machine. For example, if the machine has "long long"s,
INTMAX_C(-1) would yield
-1LL
See also, for example, "INT32_C".
Use "IV" to declare variables of the maximum usable size on this platform.
INTMAX_C(number)
"INTSIZE"
This symbol contains the value of sizeof(int) so that the C preprocessor can make
decisions based on it.
"I8SIZE"
This symbol contains the sizeof(I8).
"I16SIZE"
This symbol contains the sizeof(I16).
"I32SIZE"
This symbol contains the sizeof(I32).
"I64SIZE"
This symbol contains the sizeof(I64).
"I8TYPE"
This symbol defines the C type used for Perl's I8.
"I16TYPE"
This symbol defines the C type used for Perl's I16.
"I32TYPE"
This symbol defines the C type used for Perl's I32.
"I64TYPE"
This symbol defines the C type used for Perl's I64.
"IV"
"I8"
"I16"
"I32"
"I64"
Described in perlguts.
"IV_MAX"
The largest signed integer that fits in an IV on this platform.
IV IV_MAX
"IV_MIN"
The negative signed integer furthest away from 0 that fits in an IV on this platform.
IV IV_MIN
"IVSIZE"
This symbol contains the sizeof(IV).
"IVTYPE"
This symbol defines the C type used for Perl's IV.
"line_t"
The typedef to use to declare variables that are to hold line numbers.
"LONGLONGSIZE"
This symbol contains the size of a long long, so that the C preprocessor can make
decisions based on it. It is only defined if the system supports long long.
"LONGSIZE"
This symbol contains the value of sizeof(long) so that the C preprocessor can make
decisions based on it.
"memzero"
Set the "l" bytes starting at *d to all zeroes.
void memzero(void * d, Size_t l)
"PERL_INT_FAST8_T"
"PERL_INT_FAST16_T"
"PERL_UINT_FAST8_T"
"PERL_UINT_FAST16_T"
These are equivalent to the correspondingly-named C99 typedefs on platforms that have
those; they evaluate to "int" and "unsigned int" on platforms that don't, so that you
can portably take advantage of this C99 feature.
"PERL_INT_MAX"
"PERL_INT_MIN"
"PERL_LONG_MAX"
"PERL_LONG_MIN"
"PERL_QUAD_MAX"
"PERL_QUAD_MIN"
"PERL_SHORT_MAX"
"PERL_SHORT_MIN"
"PERL_UCHAR_MAX"
"PERL_UCHAR_MIN"
"PERL_UINT_MAX"
"PERL_UINT_MIN"
"PERL_ULONG_MAX"
"PERL_ULONG_MIN"
"PERL_UQUAD_MAX"
"PERL_UQUAD_MIN"
"PERL_USHORT_MAX"
"PERL_USHORT_MIN"
These give the largest and smallest number representable in the current platform in
variables of the corresponding types.
For signed types, the smallest representable number is the most negative number, the
one furthest away from zero.
For C99 and later compilers, these correspond to things like "INT_MAX", which are
available to the C code. But these constants, furnished by Perl, allow code compiled
on earlier compilers to portably have access to the same constants.
int PERL_INT_MAX
int PERL_INT_MIN
long PERL_LONG_MAX
long PERL_LONG_MIN
IV PERL_QUAD_MAX
IV PERL_QUAD_MIN
short PERL_SHORT_MAX
short PERL_SHORT_MIN
U8 PERL_UCHAR_MAX
U8 PERL_UCHAR_MIN
unsigned int PERL_UINT_MAX
unsigned int PERL_UINT_MIN
unsigned long PERL_ULONG_MAX
unsigned long PERL_ULONG_MIN
UV PERL_UQUAD_MAX
UV PERL_UQUAD_MIN
unsigned short PERL_USHORT_MAX
unsigned short PERL_USHORT_MIN
"SHORTSIZE"
This symbol contains the value of sizeof(short) so that the C preprocessor can make
decisions based on it.
"UINT16_C"
"UINT32_C"
"UINT64_C"
Returns a token the C compiler recognizes for the constant "number" of the
corresponding unsigned integer type on the machine.
If the machine does not have a 64-bit type, "UINT64_C" is undefined. Use "UINTMAX_C"
to get the largest type available on the platform.
U16 UINT16_C(number)
U32 UINT32_C(number)
U64 UINT64_C(number)
"UINTMAX_C"
Returns a token the C compiler recognizes for the constant "number" of the widest
unsigned integer type on the machine. For example, if the machine has "long"s,
UINTMAX_C(1) would yield
1UL
See also, for example, "UINT32_C".
Use "UV" to declare variables of the maximum usable size on this platform.
UINTMAX_C(number)
"U32of"
This symbol defines the format string used for printing a Perl U32 as an unsigned
octal integer.
"U8SIZE"
This symbol contains the sizeof(U8).
"U16SIZE"
This symbol contains the sizeof(U16).
"U32SIZE"
This symbol contains the sizeof(U32).
"U64SIZE"
This symbol contains the sizeof(U64).
"U8TYPE"
This symbol defines the C type used for Perl's U8.
"U16TYPE"
This symbol defines the C type used for Perl's U16.
"U32TYPE"
This symbol defines the C type used for Perl's U32.
"U64TYPE"
This symbol defines the C type used for Perl's U64.
"U32uf"
This symbol defines the format string used for printing a Perl U32 as an unsigned
decimal integer.
"UV"
"U8"
"U16"
"U32"
"U64"
Described in perlguts.
"UV_MAX"
The largest unsigned integer that fits in a UV on this platform.
UV UV_MAX
"UV_MIN"
The smallest unsigned integer that fits in a UV on this platform. It should equal
zero.
UV UV_MIN
"UVSIZE"
This symbol contains the sizeof(UV).
"UVTYPE"
This symbol defines the C type used for Perl's UV.
"U32Xf"
This symbol defines the format string used for printing a Perl U32 as an unsigned
hexadecimal integer in uppercase "ABCDEF".
"U32xf"
This symbol defines the format string used for printing a Perl U32 as an unsigned
hexadecimal integer in lowercase abcdef.
"WIDEST_UTYPE"
Yields the widest unsigned integer type on the platform, currently either "U32" or
"U64". This can be used in declarations such as
WIDEST_UTYPE my_uv;
or casts
my_uv = (WIDEST_UTYPE) val;
I/O Formats
These are used for formatting the corresponding type For example, instead of saying
Perl_newSVpvf(pTHX_ "Create an SV with a %d in it\n", iv);
use
Perl_newSVpvf(pTHX_ "Create an SV with a " IVdf " in it\n", iv);
This keeps you from having to know if, say an IV, needs to be printed as %d, %ld, or
something else.
"HvNAMEf"
Described in perlguts.
"HvNAMEf_QUOTEDPREFIX"
Described in perlguts.
"IVdf"
This symbol defines the format string used for printing a Perl IV as a signed decimal
integer.
"NVef"
This symbol defines the format string used for printing a Perl NV using %e-ish
floating point format.
"NVff"
This symbol defines the format string used for printing a Perl NV using %f-ish
floating point format.
"NVgf"
This symbol defines the format string used for printing a Perl NV using %g-ish
floating point format.
"PERL_PRIeldbl"
This symbol, if defined, contains the string used by stdio to format long doubles
(format 'e') for output.
"PERL_PRIfldbl"
This symbol, if defined, contains the string used by stdio to format long doubles
(format 'f') for output.
"PERL_PRIgldbl"
This symbol, if defined, contains the string used by stdio to format long doubles
(format 'g') for output.
"PERL_SCNfldbl"
This symbol, if defined, contains the string used by stdio to format long doubles
(format 'f') for input.
"PRINTF_FORMAT_NULL_OK"
Allows "__printf__" format to be null when checking printf-style
"SVf"
Described in perlguts.
"SVfARG"
Described in perlguts.
SVfARG(SV *sv)
"SVf_QUOTEDPREFIX"
Described in perlguts.
"UTF8f"
Described in perlguts.
"UTF8fARG"
Described in perlguts.
UTF8fARG(bool is_utf8, Size_t byte_len, char *str)
"UTF8f_QUOTEDPREFIX"
Described in perlguts.
"UVf"
"DEPRECATED!" It is planned to remove "UVf" from a future release of Perl. Do not
use it for new code; remove it from existing code.
Obsolete form of "UVuf", which you should convert to instead use
const char * UVf
"UVof"
This symbol defines the format string used for printing a Perl UV as an unsigned octal
integer.
"UVuf"
This symbol defines the format string used for printing a Perl UV as an unsigned
decimal integer.
"UVXf"
This symbol defines the format string used for printing a Perl UV as an unsigned
hexadecimal integer in uppercase "ABCDEF".
"UVxf"
This symbol defines the format string used for printing a Perl UV as an unsigned
hexadecimal integer in lowercase abcdef.
Lexer interface
This is the lower layer of the Perl parser, managing characters and tokens.
"BHK"
Described in perlguts.
"lex_bufutf8"
NOTE: "lex_bufutf8" is experimental and may change or be removed without notice.
Indicates whether the octets in the lexer buffer ("PL_parser->linestr") should be
interpreted as the UTF-8 encoding of Unicode characters. If not, they should be
interpreted as Latin-1 characters. This is analogous to the "SvUTF8" flag for
scalars.
In UTF-8 mode, it is not guaranteed that the lexer buffer actually contains valid
UTF-8. Lexing code must be robust in the face of invalid encoding.
The actual "SvUTF8" flag of the "PL_parser->linestr" scalar is significant, but not
the whole story regarding the input character encoding. Normally, when a file is
being read, the scalar contains octets and its "SvUTF8" flag is off, but the octets
should be interpreted as UTF-8 if the "use utf8" pragma is in effect. During a string
eval, however, the scalar may have the "SvUTF8" flag on, and in this case its octets
should be interpreted as UTF-8 unless the "use bytes" pragma is in effect. This logic
may change in the future; use this function instead of implementing the logic
yourself.
bool lex_bufutf8()
"lex_discard_to"
NOTE: "lex_discard_to" is experimental and may change or be removed without notice.
Discards the first part of the "PL_parser->linestr" buffer, up to "ptr". The
remaining content of the buffer will be moved, and all pointers into the buffer
updated appropriately. "ptr" must not be later in the buffer than the position of
"PL_parser->bufptr": it is not permitted to discard text that has yet to be lexed.
Normally it is not necessarily to do this directly, because it suffices to use the
implicit discarding behaviour of "lex_next_chunk" and things based on it. However, if
a token stretches across multiple lines, and the lexing code has kept multiple lines
of text in the buffer for that purpose, then after completion of the token it would be
wise to explicitly discard the now-unneeded earlier lines, to avoid future multi-line
tokens growing the buffer without bound.
void lex_discard_to(char *ptr)
"lex_grow_linestr"
NOTE: "lex_grow_linestr" is experimental and may change or be removed without notice.
Reallocates the lexer buffer ("PL_parser->linestr") to accommodate at least "len"
octets (including terminating "NUL"). Returns a pointer to the reallocated buffer.
This is necessary before making any direct modification of the buffer that would
increase its length. "lex_stuff_pvn" provides a more convenient way to insert text
into the buffer.
Do not use "SvGROW" or "sv_grow" directly on "PL_parser->linestr"; this function
updates all of the lexer's variables that point directly into the buffer.
char * lex_grow_linestr(STRLEN len)
"lex_next_chunk"
NOTE: "lex_next_chunk" is experimental and may change or be removed without notice.
Reads in the next chunk of text to be lexed, appending it to "PL_parser->linestr".
This should be called when lexing code has looked to the end of the current chunk and
wants to know more. It is usual, but not necessary, for lexing to have consumed the
entirety of the current chunk at this time.
If "PL_parser->bufptr" is pointing to the very end of the current chunk (i.e., the
current chunk has been entirely consumed), normally the current chunk will be
discarded at the same time that the new chunk is read in. If "flags" has the
"LEX_KEEP_PREVIOUS" bit set, the current chunk will not be discarded. If the current
chunk has not been entirely consumed, then it will not be discarded regardless of the
flag.
Returns true if some new text was added to the buffer, or false if the buffer has
reached the end of the input text.
bool lex_next_chunk(U32 flags)
"lex_peek_unichar"
NOTE: "lex_peek_unichar" is experimental and may change or be removed without notice.
Looks ahead one (Unicode) character in the text currently being lexed. Returns the
codepoint (unsigned integer value) of the next character, or -1 if lexing has reached
the end of the input text. To consume the peeked character, use "lex_read_unichar".
If the next character is in (or extends into) the next chunk of input text, the next
chunk will be read in. Normally the current chunk will be discarded at the same time,
but if "flags" has the "LEX_KEEP_PREVIOUS" bit set, then the current chunk will not be
discarded.
If the input is being interpreted as UTF-8 and a UTF-8 encoding error is encountered,
an exception is generated.
I32 lex_peek_unichar(U32 flags)
"lex_read_space"
NOTE: "lex_read_space" is experimental and may change or be removed without notice.
Reads optional spaces, in Perl style, in the text currently being lexed. The spaces
may include ordinary whitespace characters and Perl-style comments. "#line"
directives are processed if encountered. "PL_parser->bufptr" is moved past the
spaces, so that it points at a non-space character (or the end of the input text).
If spaces extend into the next chunk of input text, the next chunk will be read in.
Normally the current chunk will be discarded at the same time, but if "flags" has the
"LEX_KEEP_PREVIOUS" bit set, then the current chunk will not be discarded.
void lex_read_space(U32 flags)
"lex_read_to"
NOTE: "lex_read_to" is experimental and may change or be removed without notice.
Consume text in the lexer buffer, from "PL_parser->bufptr" up to "ptr". This advances
"PL_parser->bufptr" to match "ptr", performing the correct bookkeeping whenever a
newline character is passed. This is the normal way to consume lexed text.
Interpretation of the buffer's octets can be abstracted out by using the slightly
higher-level functions "lex_peek_unichar" and "lex_read_unichar".
void lex_read_to(char *ptr)
"lex_read_unichar"
NOTE: "lex_read_unichar" is experimental and may change or be removed without notice.
Reads the next (Unicode) character in the text currently being lexed. Returns the
codepoint (unsigned integer value) of the character read, and moves
"PL_parser->bufptr" past the character, or returns -1 if lexing has reached the end of
the input text. To non-destructively examine the next character, use
"lex_peek_unichar" instead.
If the next character is in (or extends into) the next chunk of input text, the next
chunk will be read in. Normally the current chunk will be discarded at the same time,
but if "flags" has the "LEX_KEEP_PREVIOUS" bit set, then the current chunk will not be
discarded.
If the input is being interpreted as UTF-8 and a UTF-8 encoding error is encountered,
an exception is generated.
I32 lex_read_unichar(U32 flags)
"lex_start"
NOTE: "lex_start" is experimental and may change or be removed without notice.
Creates and initialises a new lexer/parser state object, supplying a context in which
to lex and parse from a new source of Perl code. A pointer to the new state object is
placed in "PL_parser". An entry is made on the save stack so that upon unwinding, the
new state object will be destroyed and the former value of "PL_parser" will be
restored. Nothing else need be done to clean up the parsing context.
The code to be parsed comes from "line" and "rsfp". "line", if non-null, provides a
string (in SV form) containing code to be parsed. A copy of the string is made, so
subsequent modification of "line" does not affect parsing. "rsfp", if non-null,
provides an input stream from which code will be read to be parsed. If both are non-
null, the code in "line" comes first and must consist of complete lines of input, and
"rsfp" supplies the remainder of the source.
The "flags" parameter is reserved for future use. Currently it is only used by perl
internally, so extensions should always pass zero.
void lex_start(SV *line, PerlIO *rsfp, U32 flags)
"lex_stuff_pv"
NOTE: "lex_stuff_pv" is experimental and may change or be removed without notice.
Insert characters into the lexer buffer ("PL_parser->linestr"), immediately after the
current lexing point ("PL_parser->bufptr"), reallocating the buffer if necessary.
This means that lexing code that runs later will see the characters as if they had
appeared in the input. It is not recommended to do this as part of normal parsing,
and most uses of this facility run the risk of the inserted characters being
interpreted in an unintended manner.
The string to be inserted is represented by octets starting at "pv" and continuing to
the first nul. These octets are interpreted as either UTF-8 or Latin-1, according to
whether the "LEX_STUFF_UTF8" flag is set in "flags". The characters are recoded for
the lexer buffer, according to how the buffer is currently being interpreted
("lex_bufutf8"). If it is not convenient to nul-terminate a string to be inserted,
the "lex_stuff_pvn" function is more appropriate.
void lex_stuff_pv(const char *pv, U32 flags)
"lex_stuff_pvn"
NOTE: "lex_stuff_pvn" is experimental and may change or be removed without notice.
Insert characters into the lexer buffer ("PL_parser->linestr"), immediately after the
current lexing point ("PL_parser->bufptr"), reallocating the buffer if necessary.
This means that lexing code that runs later will see the characters as if they had
appeared in the input. It is not recommended to do this as part of normal parsing,
and most uses of this facility run the risk of the inserted characters being
interpreted in an unintended manner.
The string to be inserted is represented by "len" octets starting at "pv". These
octets are interpreted as either UTF-8 or Latin-1, according to whether the
"LEX_STUFF_UTF8" flag is set in "flags". The characters are recoded for the lexer
buffer, according to how the buffer is currently being interpreted ("lex_bufutf8").
If a string to be inserted is available as a Perl scalar, the "lex_stuff_sv" function
is more convenient.
void lex_stuff_pvn(const char *pv, STRLEN len, U32 flags)
"lex_stuff_pvs"
NOTE: "lex_stuff_pvs" is experimental and may change or be removed without notice.
Like "lex_stuff_pvn", but takes a literal string instead of a string/length pair.
void lex_stuff_pvs("pv", U32 flags)
"lex_stuff_sv"
NOTE: "lex_stuff_sv" is experimental and may change or be removed without notice.
Insert characters into the lexer buffer ("PL_parser->linestr"), immediately after the
current lexing point ("PL_parser->bufptr"), reallocating the buffer if necessary.
This means that lexing code that runs later will see the characters as if they had
appeared in the input. It is not recommended to do this as part of normal parsing,
and most uses of this facility run the risk of the inserted characters being
interpreted in an unintended manner.
The string to be inserted is the string value of "sv". The characters are recoded for
the lexer buffer, according to how the buffer is currently being interpreted
("lex_bufutf8"). If a string to be inserted is not already a Perl scalar, the
"lex_stuff_pvn" function avoids the need to construct a scalar.
void lex_stuff_sv(SV *sv, U32 flags)
"lex_unstuff"
NOTE: "lex_unstuff" is experimental and may change or be removed without notice.
Discards text about to be lexed, from "PL_parser->bufptr" up to "ptr". Text following
"ptr" will be moved, and the buffer shortened. This hides the discarded text from any
lexing code that runs later, as if the text had never appeared.
This is not the normal way to consume lexed text. For that, use "lex_read_to".
void lex_unstuff(char *ptr)
"parse_arithexpr"
NOTE: "parse_arithexpr" is experimental and may change or be removed without notice.
Parse a Perl arithmetic expression. This may contain operators of precedence down to
the bit shift operators. The expression must be followed (and thus terminated) either
by a comparison or lower-precedence operator or by something that would normally
terminate an expression such as semicolon. If "flags" has the "PARSE_OPTIONAL" bit
set, then the expression is optional, otherwise it is mandatory. It is up to the
caller to ensure that the dynamic parser state ("PL_parser" et al) is correctly set to
reflect the source of the code to be parsed and the lexical context for the
expression.
The op tree representing the expression is returned. If an optional expression is
absent, a null pointer is returned, otherwise the pointer will be non-null.
If an error occurs in parsing or compilation, in most cases a valid op tree is
returned anyway. The error is reflected in the parser state, normally resulting in a
single exception at the top level of parsing which covers all the compilation errors
that occurred. Some compilation errors, however, will throw an exception immediately.
OP * parse_arithexpr(U32 flags)
"parse_barestmt"
NOTE: "parse_barestmt" is experimental and may change or be removed without notice.
Parse a single unadorned Perl statement. This may be a normal imperative statement or
a declaration that has compile-time effect. It does not include any label or other
affixture. It is up to the caller to ensure that the dynamic parser state
("PL_parser" et al) is correctly set to reflect the source of the code to be parsed
and the lexical context for the statement.
The op tree representing the statement is returned. This may be a null pointer if the
statement is null, for example if it was actually a subroutine definition (which has
compile-time side effects). If not null, it will be ops directly implementing the
statement, suitable to pass to "newSTATEOP". It will not normally include a
"nextstate" or equivalent op (except for those embedded in a scope contained entirely
within the statement).
If an error occurs in parsing or compilation, in most cases a valid op tree (most
likely null) is returned anyway. The error is reflected in the parser state, normally
resulting in a single exception at the top level of parsing which covers all the
compilation errors that occurred. Some compilation errors, however, will throw an
exception immediately.
The "flags" parameter is reserved for future use, and must always be zero.
OP * parse_barestmt(U32 flags)
"parse_block"
NOTE: "parse_block" is experimental and may change or be removed without notice.
Parse a single complete Perl code block. This consists of an opening brace, a
sequence of statements, and a closing brace. The block constitutes a lexical scope,
so "my" variables and various compile-time effects can be contained within it. It is
up to the caller to ensure that the dynamic parser state ("PL_parser" et al) is
correctly set to reflect the source of the code to be parsed and the lexical context
for the statement.
The op tree representing the code block is returned. This is always a real op, never
a null pointer. It will normally be a "lineseq" list, including "nextstate" or
equivalent ops. No ops to construct any kind of runtime scope are included by virtue
of it being a block.
If an error occurs in parsing or compilation, in most cases a valid op tree (most
likely null) is returned anyway. The error is reflected in the parser state, normally
resulting in a single exception at the top level of parsing which covers all the
compilation errors that occurred. Some compilation errors, however, will throw an
exception immediately.
The "flags" parameter is reserved for future use, and must always be zero.
OP * parse_block(U32 flags)
"parse_fullexpr"
NOTE: "parse_fullexpr" is experimental and may change or be removed without notice.
Parse a single complete Perl expression. This allows the full expression grammar,
including the lowest-precedence operators such as "or". The expression must be
followed (and thus terminated) by a token that an expression would normally be
terminated by: end-of-file, closing bracketing punctuation, semicolon, or one of the
keywords that signals a postfix expression-statement modifier. If "flags" has the
"PARSE_OPTIONAL" bit set, then the expression is optional, otherwise it is mandatory.
It is up to the caller to ensure that the dynamic parser state ("PL_parser" et al) is
correctly set to reflect the source of the code to be parsed and the lexical context
for the expression.
The op tree representing the expression is returned. If an optional expression is
absent, a null pointer is returned, otherwise the pointer will be non-null.
If an error occurs in parsing or compilation, in most cases a valid op tree is
returned anyway. The error is reflected in the parser state, normally resulting in a
single exception at the top level of parsing which covers all the compilation errors
that occurred. Some compilation errors, however, will throw an exception immediately.
OP * parse_fullexpr(U32 flags)
"parse_fullstmt"
NOTE: "parse_fullstmt" is experimental and may change or be removed without notice.
Parse a single complete Perl statement. This may be a normal imperative statement or
a declaration that has compile-time effect, and may include optional labels. It is up
to the caller to ensure that the dynamic parser state ("PL_parser" et al) is correctly
set to reflect the source of the code to be parsed and the lexical context for the
statement.
The op tree representing the statement is returned. This may be a null pointer if the
statement is null, for example if it was actually a subroutine definition (which has
compile-time side effects). If not null, it will be the result of a "newSTATEOP"
call, normally including a "nextstate" or equivalent op.
If an error occurs in parsing or compilation, in most cases a valid op tree (most
likely null) is returned anyway. The error is reflected in the parser state, normally
resulting in a single exception at the top level of parsing which covers all the
compilation errors that occurred. Some compilation errors, however, will throw an
exception immediately.
The "flags" parameter is reserved for future use, and must always be zero.
OP * parse_fullstmt(U32 flags)
"parse_label"
NOTE: "parse_label" is experimental and may change or be removed without notice.
Parse a single label, possibly optional, of the type that may prefix a Perl statement.
It is up to the caller to ensure that the dynamic parser state ("PL_parser" et al) is
correctly set to reflect the source of the code to be parsed. If "flags" has the
"PARSE_OPTIONAL" bit set, then the label is optional, otherwise it is mandatory.
The name of the label is returned in the form of a fresh scalar. If an optional label
is absent, a null pointer is returned.
If an error occurs in parsing, which can only occur if the label is mandatory, a valid
label is returned anyway. The error is reflected in the parser state, normally
resulting in a single exception at the top level of parsing which covers all the
compilation errors that occurred.
SV * parse_label(U32 flags)
"parse_listexpr"
NOTE: "parse_listexpr" is experimental and may change or be removed without notice.
Parse a Perl list expression. This may contain operators of precedence down to the
comma operator. The expression must be followed (and thus terminated) either by a
low-precedence logic operator such as "or" or by something that would normally
terminate an expression such as semicolon. If "flags" has the "PARSE_OPTIONAL" bit
set, then the expression is optional, otherwise it is mandatory. It is up to the
caller to ensure that the dynamic parser state ("PL_parser" et al) is correctly set to
reflect the source of the code to be parsed and the lexical context for the
expression.
The op tree representing the expression is returned. If an optional expression is
absent, a null pointer is returned, otherwise the pointer will be non-null.
If an error occurs in parsing or compilation, in most cases a valid op tree is
returned anyway. The error is reflected in the parser state, normally resulting in a
single exception at the top level of parsing which covers all the compilation errors
that occurred. Some compilation errors, however, will throw an exception immediately.
OP * parse_listexpr(U32 flags)
"parse_stmtseq"
NOTE: "parse_stmtseq" is experimental and may change or be removed without notice.
Parse a sequence of zero or more Perl statements. These may be normal imperative
statements, including optional labels, or declarations that have compile-time effect,
or any mixture thereof. The statement sequence ends when a closing brace or end-of-
file is encountered in a place where a new statement could have validly started. It
is up to the caller to ensure that the dynamic parser state ("PL_parser" et al) is
correctly set to reflect the source of the code to be parsed and the lexical context
for the statements.
The op tree representing the statement sequence is returned. This may be a null
pointer if the statements were all null, for example if there were no statements or if
there were only subroutine definitions (which have compile-time side effects). If not
null, it will be a "lineseq" list, normally including "nextstate" or equivalent ops.
If an error occurs in parsing or compilation, in most cases a valid op tree is
returned anyway. The error is reflected in the parser state, normally resulting in a
single exception at the top level of parsing which covers all the compilation errors
that occurred. Some compilation errors, however, will throw an exception immediately.
The "flags" parameter is reserved for future use, and must always be zero.
OP * parse_stmtseq(U32 flags)
"parse_subsignature"
NOTE: "parse_subsignature" is experimental and may change or be removed without
notice.
Parse a subroutine signature declaration. This is the contents of the parentheses
following a named or anonymous subroutine declaration when the "signatures" feature is
enabled. Note that this function neither expects nor consumes the opening and closing
parentheses around the signature; it is the caller's job to handle these.
This function must only be called during parsing of a subroutine; after
"start_subparse" has been called. It might allocate lexical variables on the pad for
the current subroutine.
The op tree to unpack the arguments from the stack at runtime is returned. This op
tree should appear at the beginning of the compiled function. The caller may wish to
use "op_append_list" to build their function body after it, or splice it together with
the body before calling "newATTRSUB".
The "flags" parameter is reserved for future use, and must always be zero.
OP * parse_subsignature(U32 flags)
"parse_termexpr"
NOTE: "parse_termexpr" is experimental and may change or be removed without notice.
Parse a Perl term expression. This may contain operators of precedence down to the
assignment operators. The expression must be followed (and thus terminated) either by
a comma or lower-precedence operator or by something that would normally terminate an
expression such as semicolon. If "flags" has the "PARSE_OPTIONAL" bit set, then the
expression is optional, otherwise it is mandatory. It is up to the caller to ensure
that the dynamic parser state ("PL_parser" et al) is correctly set to reflect the
source of the code to be parsed and the lexical context for the expression.
The op tree representing the expression is returned. If an optional expression is
absent, a null pointer is returned, otherwise the pointer will be non-null.
If an error occurs in parsing or compilation, in most cases a valid op tree is
returned anyway. The error is reflected in the parser state, normally resulting in a
single exception at the top level of parsing which covers all the compilation errors
that occurred. Some compilation errors, however, will throw an exception immediately.
OP * parse_termexpr(U32 flags)
"PL_parser"
Pointer to a structure encapsulating the state of the parsing operation currently in
progress. The pointer can be locally changed to perform a nested parse without
interfering with the state of an outer parse. Individual members of "PL_parser" have
their own documentation.
"PL_parser->bufend"
NOTE: "PL_parser->bufend" is experimental and may change or be removed without notice.
Direct pointer to the end of the chunk of text currently being lexed, the end of the
lexer buffer. This is equal to "SvPVX(PL_parser->linestr) +
SvCUR(PL_parser->linestr)". A "NUL" character (zero octet) is always located at the
end of the buffer, and does not count as part of the buffer's contents.
"PL_parser->bufptr"
NOTE: "PL_parser->bufptr" is experimental and may change or be removed without notice.
Points to the current position of lexing inside the lexer buffer. Characters around
this point may be freely examined, within the range delimited by
SvPVX("PL_parser->linestr") and "PL_parser->bufend". The octets of the buffer may be
intended to be interpreted as either UTF-8 or Latin-1, as indicated by "lex_bufutf8".
Lexing code (whether in the Perl core or not) moves this pointer past the characters
that it consumes. It is also expected to perform some bookkeeping whenever a newline
character is consumed. This movement can be more conveniently performed by the
function "lex_read_to", which handles newlines appropriately.
Interpretation of the buffer's octets can be abstracted out by using the slightly
higher-level functions "lex_peek_unichar" and "lex_read_unichar".
"PL_parser->linestart"
NOTE: "PL_parser->linestart" is experimental and may change or be removed without
notice.
Points to the start of the current line inside the lexer buffer. This is useful for
indicating at which column an error occurred, and not much else. This must be updated
by any lexing code that consumes a newline; the function "lex_read_to" handles this
detail.
"PL_parser->linestr"
NOTE: "PL_parser->linestr" is experimental and may change or be removed without
notice.
Buffer scalar containing the chunk currently under consideration of the text currently
being lexed. This is always a plain string scalar (for which "SvPOK" is true). It is
not intended to be used as a scalar by normal scalar means; instead refer to the
buffer directly by the pointer variables described below.
The lexer maintains various "char*" pointers to things in the "PL_parser->linestr"
buffer. If "PL_parser->linestr" is ever reallocated, all of these pointers must be
updated. Don't attempt to do this manually, but rather use "lex_grow_linestr" if you
need to reallocate the buffer.
The content of the text chunk in the buffer is commonly exactly one complete line of
input, up to and including a newline terminator, but there are situations where it is
otherwise. The octets of the buffer may be intended to be interpreted as either UTF-8
or Latin-1. The function "lex_bufutf8" tells you which. Do not use the "SvUTF8" flag
on this scalar, which may disagree with it.
For direct examination of the buffer, the variable "PL_parser->bufend" points to the
end of the buffer. The current lexing position is pointed to by "PL_parser->bufptr".
Direct use of these pointers is usually preferable to examination of the scalar
through normal scalar means.
"suspend_compcv"
Implements part of the concept of a "suspended compilation CV", which can be used to
pause the parser and compiler during parsing a CV in order to come back to it later
on.
This function saves the current state of the subroutine under compilation
("PL_compcv") into the supplied buffer. This should be used initially to create the
state in the buffer, as the final thing before a "LEAVE" within a block.
ENTER;
start_subparse(0);
...
suspend_compcv(&buffer);
LEAVE;
Once suspended, the "resume_compcv_final" or "resume_compcv_and_save" function can
later be used to continue the parsing from the point this stopped.
void suspend_compcv(struct suspended_compcv *buffer)
"wrap_infix_plugin"
NOTE: "wrap_infix_plugin" is experimental and may change or be removed without notice.
NOTE: This API exists entirely for the purpose of making the CPAN module
"XS::Parse::Infix" work. It is not expected that additional modules will make use of
it; rather, that they should use "XS::Parse::Infix" to provide parsing of new infix
operators.
Puts a C function into the chain of infix plugins. This is the preferred way to
manipulate the "PL_infix_plugin" variable. "new_plugin" is a pointer to the C
function that is to be added to the infix plugin chain, and "old_plugin_p" points to a
storage location where a pointer to the next function in the chain will be stored.
The value of "new_plugin" is written into the "PL_infix_plugin" variable, while the
value previously stored there is written to *old_plugin_p.
Direct access to "PL_infix_plugin" should be avoided.
void wrap_infix_plugin(Perl_infix_plugin_t new_plugin,
Perl_infix_plugin_t *old_plugin_p)
"wrap_keyword_plugin"
NOTE: "wrap_keyword_plugin" is experimental and may change or be removed without
notice.
Puts a C function into the chain of keyword plugins. This is the preferred way to
manipulate the "PL_keyword_plugin" variable. "new_plugin" is a pointer to the C
function that is to be added to the keyword plugin chain, and "old_plugin_p" points to
the storage location where a pointer to the next function in the chain will be stored.
The value of "new_plugin" is written into the "PL_keyword_plugin" variable, while the
value previously stored there is written to *old_plugin_p.
"PL_keyword_plugin" is global to an entire process, and a module wishing to hook
keyword parsing may find itself invoked more than once per process, typically in
different threads. To handle that situation, this function is idempotent. The
location *old_plugin_p must initially (once per process) contain a null pointer. A C
variable of static duration (declared at file scope, typically also marked "static" to
give it internal linkage) will be implicitly initialised appropriately, if it does not
have an explicit initialiser. This function will only actually modify the plugin
chain if it finds *old_plugin_p to be null. This function is also thread safe on the
small scale. It uses appropriate locking to avoid race conditions in accessing
"PL_keyword_plugin".
When this function is called, the function referenced by "new_plugin" must be ready to
be called, except for *old_plugin_p being unfilled. In a threading situation,
"new_plugin" may be called immediately, even before this function has returned.
*old_plugin_p will always be appropriately set before "new_plugin" is called. If
"new_plugin" decides not to do anything special with the identifier that it is given
(which is the usual case for most calls to a keyword plugin), it must chain the plugin
function referenced by *old_plugin_p.
Taken all together, XS code to install a keyword plugin should typically look
something like this:
static Perl_keyword_plugin_t next_keyword_plugin;
static OP *my_keyword_plugin(pTHX_
char *keyword_ptr, STRLEN keyword_len, OP **op_ptr)
{
if (memEQs(keyword_ptr, keyword_len,
"my_new_keyword")) {
...
} else {
return next_keyword_plugin(aTHX_
keyword_ptr, keyword_len, op_ptr);
}
}
BOOT:
wrap_keyword_plugin(my_keyword_plugin,
&next_keyword_plugin);
Direct access to "PL_keyword_plugin" should be avoided.
void wrap_keyword_plugin(Perl_keyword_plugin_t new_plugin,
Perl_keyword_plugin_t *old_plugin_p)
Locales
"DECLARATION_FOR_LC_NUMERIC_MANIPULATION"
This macro should be used as a statement. It declares a private variable (whose name
begins with an underscore) that is needed by the other macros in this section.
Failing to include this correctly should lead to a syntax error. For compatibility
with C89 C compilers it should be placed in a block before any executable statements.
void DECLARATION_FOR_LC_NUMERIC_MANIPULATION
"foldEQ_locale"
Returns true if the leading "len" bytes of the strings "s1" and "s2" are the same
case-insensitively in the current locale; false otherwise.
I32 foldEQ_locale(const char *a, const char *b, I32 len)
"HAS_DUPLOCALE"
This symbol, if defined, indicates that the "duplocale" routine is available to
duplicate a locale object.
"HAS_FREELOCALE"
This symbol, if defined, indicates that the "freelocale" routine is available to
deallocates the resources associated with a locale object.
"HAS_LC_MONETARY_2008"
This symbol, if defined, indicates that the localeconv routine is available and has
the additional members added in "POSIX" 1003.1-2008.
"HAS_LOCALECONV"
This symbol, if defined, indicates that the "localeconv" routine is available for
numeric and monetary formatting conventions.
"HAS_LOCALECONV_L"
This symbol, if defined, indicates that the "localeconv_l" routine is available to
query certain information about a locale.
"HAS_NEWLOCALE"
This symbol, if defined, indicates that the "newlocale" routine is available to return
a new locale object or modify an existing locale object.
"HAS_NL_LANGINFO"
This symbol, if defined, indicates that the "nl_langinfo" routine is available to
return locale data. You will also need langinfo.h and therefore "I_LANGINFO".
"HAS_NL_LANGINFO_L"
This symbol, if defined, indicates that the "nl_langinfo_l" routine is available to
return locale data. You will also need langinfo.h and therefore "I_LANGINFO".
"HAS_QUERYLOCALE"
This symbol, if defined, indicates that the "querylocale" routine is available to
return the name of the locale for a category mask.
"HAS_SETLOCALE"
This symbol, if defined, indicates that the "setlocale" routine is available to handle
locale-specific ctype implementations.
"HAS_SETLOCALE_R"
This symbol, if defined, indicates that the "setlocale_r" routine is available to
setlocale re-entrantly.
"HAS_USELOCALE"
This symbol, if defined, indicates that the "uselocale" routine is available to set
the current locale for the calling thread.
"I_LANGINFO"
This symbol, if defined, indicates that langinfo.h exists and should be included.
#ifdef I_LANGINFO
#include <langinfo.h>
#endif
"I_LOCALE"
This symbol, if defined, indicates to the C program that it should include locale.h.
#ifdef I_LOCALE
#include <locale.h>
#endif
"IN_LOCALE"
Evaluates to TRUE if the plain locale pragma without a parameter ("use locale") is in
effect.
bool IN_LOCALE
"IN_LOCALE_COMPILETIME"
Evaluates to TRUE if, when compiling a perl program (including an "eval") if the plain
locale pragma without a parameter ("use locale") is in effect.
bool IN_LOCALE_COMPILETIME
"IN_LOCALE_RUNTIME"
Evaluates to TRUE if, when executing a perl program (including an "eval") if the plain
locale pragma without a parameter ("use locale") is in effect.
bool IN_LOCALE_RUNTIME
"I_XLOCALE"
This symbol, if defined, indicates to the C program that the header xlocale.h is
available. See also "NEED_XLOCALE_H"
#ifdef I_XLOCALE
#include <xlocale.h>
#endif
"NEED_XLOCALE_H"
This symbol, if defined, indicates that the C program should include xlocale.h to get
newlocale() and its friends.
"Perl_langinfo"
"Perl_langinfo8"
"Perl_langinfo" is an (almost) drop-in replacement for the system nl_langinfo(3),
taking the same "item" parameter values, and returning the same information. But it
is more thread-safe than regular nl_langinfo(), and hides the quirks of Perl's locale
handling from your code, and can be used on systems that lack a native "nl_langinfo".
However, you should instead use either the improved version of this, "Perl_langinfo8",
or even better, "sv_langinfo". The latter returns an SV, handling all the possible
non-standard returns of nl_langinfo(), including the UTF8ness of any returned string.
"Perl_langinfo8" is identical to "Perl_langinfo" except for an additional parameter, a
pointer to a variable declared as ""utf8ness_t"", into which it returns to you how you
should treat the returned string with regards to it being encoded in UTF-8 or not.
These two functions share private per-thread memory that will be changed the next time
either one of them is called with any input, but not before.
Concerning the differences between these and plain nl_langinfo():
a. "Perl_langinfo8" has an extra parameter, described above. Besides this, the other
reason they aren't quite a drop-in replacement is actually an advantage. The
"const"ness of the return allows the compiler to catch attempts to write into the
returned buffer, which is illegal and could cause run-time crashes.
b. They deliver the correct results for the "RADIXCHAR" and "THOUSEP" items, without
you having to write extra code. The reason for the extra code would be because
these are from the "LC_NUMERIC" locale category, which is normally kept set by
Perl so that the radix is a dot, and the separator is the empty string, no matter
what the underlying locale is supposed to be, and so to get the expected results,
you have to temporarily toggle into the underlying locale, and later toggle back.
(You could use plain "nl_langinfo" and "STORE_LC_NUMERIC_FORCE_TO_UNDERLYING" for
this but then you wouldn't get the other advantages of Perl_langinfo(); not
keeping "LC_NUMERIC" in the C (or equivalent) locale would break a lot of CPAN,
which is expecting the radix (decimal point) character to be a dot.)
c. The system function they replace can have its static return buffer trashed, not
only by a subsequent call to that function, but by a "freelocale", "setlocale", or
other locale change. The returned buffer of these functions is not changed until
the next call to one or the other, so the buffer is never in a trashed state.
d. The return buffer is per-thread, so it also is never overwritten by a call to
these functions from another thread; unlike the function it replaces.
e. But most importantly, they work on systems that don't have "nl_langinfo", such as
Windows, hence making your code more portable. Of the fifty-some possible items
specified by the POSIX 2008 standard,
<https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/langinfo.h.html>, only
one is completely unimplemented, though on non-Windows platforms, another
significant one is not fully implemented). They use various techniques to recover
the other items, including calling localeconv(3), and strftime(3), both of which
are specified in C89, so should be always be available. Later strftime() versions
have additional capabilities. If an item is not available on your system, this
returns either the value associated with the C locale, or simply "", whichever is
more appropriate.
It is important to note that, when called with an item that is recovered by using
"localeconv", the buffer from any previous explicit call to localeconv(3) will be
overwritten. But you shouldn't be using "localeconv" anyway because it is is very
much not thread-safe, and suffers from the same problems outlined in item 'b.'
above for the fields it returns that are controlled by the LC_NUMERIC locale
category. Instead, avoid all of those problems by calling "Perl_localeconv",
which is thread-safe; or by using the methods given in perlcall to call
POSIX::localeconv(), which is also thread-safe.
The details for those items which may deviate from what this emulation returns and
what a native nl_langinfo() would return are specified in I18N::Langinfo.
const char * Perl_langinfo (const nl_item item)
const char * Perl_langinfo8(const nl_item item,
utf8ness_t *utf8ness)
"PERL_LC_ALL_CATEGORY_POSITIONS_INIT"
This symbol, when defined, gives the C initializer for an array whose element [0] is
the first category in the string returned by "setlocale(LC_ALL, NULL)" when not all
categories are the same, on systems that use a positional notation. After element [0]
is "LC_ALL_SEPARATOR", then the category given by element [1] and so on.
"PERL_LC_ALL_SEPARATOR"
This symbol, if defined, gives the string returned by "setlocale(LC_ALL, NULL)" to
separate categories that are in different locales on systems that use a positional
notation as opposed to 'name=value' pairs. An example on some platforms could be the
'/' in "C/"de_DE"/C/"en_UK"/C/C"
"PERL_LC_ALL_USES_NAME_VALUE_PAIRS"
This symbol, if defined, indicates to the C program that the string returned by
"setlocale(LC_ALL, NULL)" uses 'name=value;' pairs to indicate what each category's
locale is when they aren't all set to the same locale. For example,
""LC_NUMERIC"=C;"LC_CTYPE"="de_DE";..." When not defined, the system uses positional
notation.
"Perl_localeconv"
This is a thread-safe version of the libc localeconv(3). It is the same as
POSIX::localeconv (returning a hash of the localeconv() fields), but directly callable
from XS code. The hash is mortalized, so must be dealt with immediately.
HV * Perl_localeconv(pTHX)
"Perl_setlocale"
This is an (almost) drop-in replacement for the system setlocale(3), taking the same
parameters, and returning the same information, except that it returns the correct
underlying "LC_NUMERIC" locale. Regular "setlocale" will instead return "C" if the
underlying locale has a non-dot decimal point character, or a non-empty thousands
separator for displaying floating point numbers. This is because perl keeps that
locale category such that it has a dot and empty separator, changing the locale
briefly during the operations where the underlying one is required. "Perl_setlocale"
knows about this, and compensates; regular "setlocale" doesn't.
Another reason it isn't completely a drop-in replacement is that it is declared to
return "const char *", whereas the system setlocale omits the "const" (presumably
because its API was specified long ago, and can't be updated; it is illegal to change
the information "setlocale" returns; doing so leads to segfaults.)
Finally, "Perl_setlocale" works under all circumstances, whereas plain "setlocale" can
be completely ineffective on some platforms under some configurations.
Changing the locale is not a good idea when more than one thread is running, except on
systems where the predefined variable "${^SAFE_LOCALES}" is non-zero. This is because
on such systems the locale is global to the whole process and not local to just the
thread calling the function. So changing it in one thread instantaneously changes it
in all. On some such systems, the system setlocale() is ineffective, returning the
wrong information, and failing to actually change the locale. z/OS refuses to try to
change the locale once a second thread is created. "Perl_setlocale", should give you
accurate results of what actually happened on these problematic platforms, returning
NULL if the system forbade the locale change.
The return points to a per-thread static buffer, which is overwritten the next time
"Perl_setlocale" is called from the same thread.
const char * Perl_setlocale(const int category,
const char *locale)
"RESTORE_LC_NUMERIC"
This is used in conjunction with one of the macros "STORE_LC_NUMERIC_SET_TO_NEEDED"
and "STORE_LC_NUMERIC_FORCE_TO_UNDERLYING" to properly restore the "LC_NUMERIC" state.
A call to "DECLARATION_FOR_LC_NUMERIC_MANIPULATION" must have been made to declare at
compile time a private variable used by this macro and the two "STORE" ones. This
macro should be called as a single statement, not an expression, but with an empty
argument list, like this:
{
DECLARATION_FOR_LC_NUMERIC_MANIPULATION;
...
RESTORE_LC_NUMERIC();
...
}
void RESTORE_LC_NUMERIC()
"SETLOCALE_ACCEPTS_ANY_LOCALE_NAME"
This symbol, if defined, indicates that the setlocale routine is available and it
accepts any input locale name as valid.
"STORE_LC_NUMERIC_FORCE_TO_UNDERLYING"
This is used by XS code that is "LC_NUMERIC" locale-aware to force the locale for
category "LC_NUMERIC" to be what perl thinks is the current underlying locale. (The
perl interpreter could be wrong about what the underlying locale actually is if some C
or XS code has called the C library function setlocale(3) behind its back; calling
"sync_locale" before calling this macro will update perl's records.)
A call to "DECLARATION_FOR_LC_NUMERIC_MANIPULATION" must have been made to declare at
compile time a private variable used by this macro. This macro should be called as a
single statement, not an expression, but with an empty argument list, like this:
{
DECLARATION_FOR_LC_NUMERIC_MANIPULATION;
...
STORE_LC_NUMERIC_FORCE_TO_UNDERLYING();
...
RESTORE_LC_NUMERIC();
...
}
The private variable is used to save the current locale state, so that the requisite
matching call to "RESTORE_LC_NUMERIC" can restore it.
On threaded perls not operating with thread-safe functionality, this macro uses a
mutex to force a critical section. Therefore the matching RESTORE should be close by,
and guaranteed to be called.
void STORE_LC_NUMERIC_FORCE_TO_UNDERLYING()
"STORE_LC_NUMERIC_SET_TO_NEEDED"
This is used to help wrap XS or C code that is "LC_NUMERIC" locale-aware. This locale
category is generally kept set to a locale where the decimal radix character is a dot,
and the separator between groups of digits is empty. This is because most XS code
that reads floating point numbers is expecting them to have this syntax.
This macro makes sure the current "LC_NUMERIC" state is set properly, to be aware of
locale if the call to the XS or C code from the Perl program is from within the scope
of a "use locale"; or to ignore locale if the call is instead from outside such scope.
This macro is the start of wrapping the C or XS code; the wrap ending is done by
calling the "RESTORE_LC_NUMERIC" macro after the operation. Otherwise the state can
be changed that will adversely affect other XS code.
A call to "DECLARATION_FOR_LC_NUMERIC_MANIPULATION" must have been made to declare at
compile time a private variable used by this macro. This macro should be called as a
single statement, not an expression, but with an empty argument list, like this:
{
DECLARATION_FOR_LC_NUMERIC_MANIPULATION;
...
STORE_LC_NUMERIC_SET_TO_NEEDED();
...
RESTORE_LC_NUMERIC();
...
}
On threaded perls not operating with thread-safe functionality, this macro uses a
mutex to force a critical section. Therefore the matching RESTORE should be close by,
and guaranteed to be called; see "WITH_LC_NUMERIC_SET_TO_NEEDED" for a more contained
way to ensure that.
void STORE_LC_NUMERIC_SET_TO_NEEDED()
"STORE_LC_NUMERIC_SET_TO_NEEDED_IN"
Same as "STORE_LC_NUMERIC_SET_TO_NEEDED" with in_lc_numeric provided as the
precalculated value of IN_LC(LC_NUMERIC). It is the caller's responsibility to ensure
that the status of "PL_compiling" and "PL_hints" cannot have changed since the
precalculation.
void STORE_LC_NUMERIC_SET_TO_NEEDED_IN(bool in_lc_numeric)
"sv_langinfo"
This is the preferred interface for accessing the data that nl_langinfo(3) provides
(or Perl's emulation of it on platforms lacking it), returning an SV. Unlike, the
earlier-defined interfaces to this ("Perl_langinfo" and "Perl_langinfo8"), which
return strings, the UTF8ness of the result is automatically handled for you. And like
them, it is thread-safe and automatically handles getting the proper values for the
"RADIXCHAR" and "THOUSEP" items (that calling the plain libc nl_langinfo() could give
the wrong results for). Like them, this also doesn't play well with the libc
localeconv(); use POSIX::localeconv() instead.
There are a few deviations from what a native nl_langinfo() would return and what this
returns on platforms that don't implement that function. These are detailed in
I18N::Langinfo.
SV * sv_langinfo(const nl_item item)
"switch_to_global_locale"
This function copies the locale state of the calling thread into the program's global
locale, and converts the thread to use that global locale.
It is intended so that Perl can safely be used with C libraries that access the global
locale and which can't be converted to not access it. Effectively, this means
libraries that call setlocale(3) on non-Windows systems. (For portability, it is a
good idea to use it on Windows as well.)
A downside of using it is that it disables the services that Perl provides to hide
locale gotchas from your code. The service you most likely will miss regards the
radix character (decimal point) in floating point numbers. Code executed after this
function is called can no longer just assume that this character is correct for the
current circumstances.
To return to Perl control, and restart the gotcha prevention services, call
"sync_locale". Behavior is undefined for any pure Perl code that executes while the
switch is in effect.
The global locale and the per-thread locales are independent. As long as just one
thread converts to the global locale, everything works smoothly. But if more than one
does, they can easily interfere with each other, and races are likely. On Windows
systems prior to Visual Studio 15 (at which point Microsoft fixed a bug), races can
occur (even if only one thread has been converted to the global locale), but only if
you use the following operations:
POSIX::localeconv
I18N::Langinfo, items "CRNCYSTR" and "THOUSEP"
"sv_langinfo" in perlapi, items "CRNCYSTR" and "THOUSEP"
The first item is not fixable (except by upgrading to a later Visual Studio release),
but it would be possible to work around the latter two items by having Perl change its
algorithm for calculating these to use Windows API functions (likely "GetNumberFormat"
and "GetCurrencyFormat"); patches welcome.
XS code should never call plain "setlocale", but should instead be converted to either
call "Perl_setlocale" (which is a drop-in for the system "setlocale") or use the
methods given in perlcall to call "POSIX::setlocale". Either one will transparently
properly handle all cases of single- vs multi-thread, POSIX 2008-supported or not.
void switch_to_global_locale()
"sync_locale"
This function copies the state of the program global locale into the calling thread,
and converts that thread to using per-thread locales, if it wasn't already, and the
platform supports them. The LC_NUMERIC locale is toggled into the standard state
(using the C locale's conventions), if not within the lexical scope of "use locale".
Perl will now consider itself to have control of the locale.
Since unthreaded perls have only a global locale, this function is a no-op without
threads.
This function is intended for use with C libraries that do locale manipulation. It
allows Perl to accommodate the use of them. Call this function before transferring
back to Perl space so that it knows what state the C code has left things in.
XS code should not manipulate the locale on its own. Instead, "Perl_setlocale" can be
used at any time to query or change the locale (though changing the locale is
antisocial and dangerous on multi-threaded systems that don't have multi-thread safe
locale operations. (See "Multi-threaded operation" in perllocale).
Using the libc setlocale(3) function should be avoided. Nevertheless, certain non-
Perl libraries called from XS, do call it, and their behavior may not be able to be
changed. This function, along with "switch_to_global_locale", can be used to get
seamless behavior in these circumstances, as long as only one thread is involved.
If the library has an option to turn off its locale manipulation, doing that is
preferable to using this mechanism. "Gtk" is such a library.
The return value is a boolean: TRUE if the global locale at the time of call was in
effect for the caller; and FALSE if a per-thread locale was in effect.
bool sync_locale()
"WITH_LC_NUMERIC_SET_TO_NEEDED"
This macro invokes the supplied statement or block within the context of a
"STORE_LC_NUMERIC_SET_TO_NEEDED" .. "RESTORE_LC_NUMERIC" pair if required, so eg:
WITH_LC_NUMERIC_SET_TO_NEEDED(
SNPRINTF_G(fv, ebuf, sizeof(ebuf), precis)
);
is equivalent to:
{
#ifdef USE_LOCALE_NUMERIC
DECLARATION_FOR_LC_NUMERIC_MANIPULATION;
STORE_LC_NUMERIC_SET_TO_NEEDED();
#endif
SNPRINTF_G(fv, ebuf, sizeof(ebuf), precis);
#ifdef USE_LOCALE_NUMERIC
RESTORE_LC_NUMERIC();
#endif
}
void WITH_LC_NUMERIC_SET_TO_NEEDED(block)
"WITH_LC_NUMERIC_SET_TO_NEEDED_IN"
Same as "WITH_LC_NUMERIC_SET_TO_NEEDED" with in_lc_numeric provided as the
precalculated value of IN_LC(LC_NUMERIC). It is the caller's responsibility to ensure
that the status of "PL_compiling" and "PL_hints" cannot have changed since the
precalculation.
void WITH_LC_NUMERIC_SET_TO_NEEDED_IN(bool in_lc_numeric, block)
Magic
"Magic" is special data attached to SV structures in order to give them "magical"
properties. When any Perl code tries to read from, or assign to, an SV marked as magical,
it calls the 'get' or 'set' function associated with that SV's magic. A get is called
prior to reading an SV, in order to give it a chance to update its internal value (get on
$. writes the line number of the last read filehandle into the SV's IV slot), while set is
called after an SV has been written to, in order to allow it to make use of its changed
value (set on $/ copies the SV's new value to the PL_rs global variable).
Magic is implemented as a linked list of MAGIC structures attached to the SV. Each MAGIC
struct holds the type of the magic, a pointer to an array of functions that implement the
get(), set(), length() etc functions, plus space for some flags and pointers. For
example, a tied variable has a MAGIC structure that contains a pointer to the object
associated with the tie.
"mg_clear"
Clear something magical that the SV represents. See "sv_magic".
int mg_clear(SV *sv)
"mg_copy"
Copies the magic from one SV to another. See "sv_magic".
int mg_copy(SV *sv, SV *nsv, const char *key, I32 klen)
"MGf_COPY"
"MGf_DUP"
"MGf_LOCAL"
Described in perlguts.
"mg_find"
Finds the magic pointer for "type" matching the SV. See "sv_magic".
MAGIC * mg_find(const SV *sv, int type)
"mg_findext"
Finds the magic pointer of "type" with the given "vtbl" for the "SV". See
"sv_magicext".
MAGIC * mg_findext(const SV *sv, int type, const MGVTBL *vtbl)
"mg_free"
Free any magic storage used by the SV. See "sv_magic".
int mg_free(SV *sv)
"mg_freeext"
Remove any magic of type "how" using virtual table "vtbl" from the SV "sv". See
"sv_magic".
"mg_freeext(sv, how, NULL)" is equivalent to "mg_free_type(sv, how)".
void mg_freeext(SV *sv, int how, const MGVTBL *vtbl)
"mg_free_type"
Remove any magic of type "how" from the SV "sv". See "sv_magic".
void mg_free_type(SV *sv, int how)
"mg_get"
Do magic before a value is retrieved from the SV. The type of SV must be >=
"SVt_PVMG". See "sv_magic".
int mg_get(SV *sv)
"mg_magical"
Turns on the magical status of an SV. See "sv_magic".
void mg_magical(SV *sv)
"mg_set"
Do magic after a value is assigned to the SV. See "sv_magic".
int mg_set(SV *sv)
"MGVTBL"
Described in perlguts.
"PERL_MAGIC_arylen"
"PERL_MAGIC_arylen_p"
"PERL_MAGIC_backref"
"PERL_MAGIC_bm"
"PERL_MAGIC_checkcall"
"PERL_MAGIC_collxfrm"
"PERL_MAGIC_dbfile"
"PERL_MAGIC_dbline"
"PERL_MAGIC_debugvar"
"PERL_MAGIC_defelem"
"PERL_MAGIC_destruct"
"PERL_MAGIC_env"
"PERL_MAGIC_envelem"
"PERL_MAGIC_ext"
"PERL_MAGIC_extvalue"
"PERL_MAGIC_fm"
"PERL_MAGIC_hints"
"PERL_MAGIC_hintselem"
"PERL_MAGIC_hook"
"PERL_MAGIC_hookelem"
"PERL_MAGIC_isa"
"PERL_MAGIC_isaelem"
"PERL_MAGIC_lvref"
"PERL_MAGIC_nkeys"
"PERL_MAGIC_nonelem"
"PERL_MAGIC_overload_table"
"PERL_MAGIC_pos"
"PERL_MAGIC_qr"
"PERL_MAGIC_regdata"
"PERL_MAGIC_regdatum"
"PERL_MAGIC_regex_global"
"PERL_MAGIC_rhash"
"PERL_MAGIC_shared"
"PERL_MAGIC_shared_scalar"
"PERL_MAGIC_sig"
"PERL_MAGIC_sigelem"
"PERL_MAGIC_substr"
"PERL_MAGIC_sv"
"PERL_MAGIC_symtab"
"PERL_MAGIC_taint"
"PERL_MAGIC_tied"
"PERL_MAGIC_tiedelem"
"PERL_MAGIC_tiedscalar"
"PERL_MAGIC_utf8"
"PERL_MAGIC_uvar"
"PERL_MAGIC_uvar_elem"
"PERL_MAGIC_vec"
"PERL_MAGIC_vstring"
Described in perlguts.
"SvTIED_obj"
Described in perlinterp.
SvTIED_obj(SV *sv, MAGIC *mg)
Memory Management
"dump_mstats"
When enabled by compiling with "-DDEBUGGING_MSTATS", print out statistics about malloc
as two lines of numbers, one showing the length of the free list for each size
category, the second showing the number of mallocs - frees for each size category.
"s", if not NULL, is used as a phrase to include in the output, such as
"after compilation".
void dump_mstats(const char *s)
"HASATTRIBUTE_MALLOC"
Can we handle "GCC" attribute for malloc-style functions.
"HAS_MALLOC_GOOD_SIZE"
This symbol, if defined, indicates that the "malloc_good_size" routine is available
for use.
"HAS_MALLOC_SIZE"
This symbol, if defined, indicates that the "malloc_size" routine is available for
use.
"I_MALLOCMALLOC"
This symbol, if defined, indicates to the C program that it should include
malloc/malloc.h.
#ifdef I_MALLOCMALLOC
#include <mallocmalloc.h>
#endif
"MYMALLOC"
This symbol, if defined, indicates that we're using our own malloc.
"Newx"
"safemalloc"
The XSUB-writer's interface to the C "malloc" function.
Memory obtained by this should ONLY be freed with "Safefree".
In 5.9.3, Newx() and friends replace the older New() API, and drops the first
parameter, x, a debug aid which allowed callers to identify themselves. This aid has
been superseded by a new build option, PERL_MEM_LOG (see "PERL_MEM_LOG" in
perlhacktips). The older API is still there for use in XS modules supporting older
perls.
void Newx (void* ptr, int nitems, type)
void* safemalloc(size_t size)
"Newxc"
The XSUB-writer's interface to the C "malloc" function, with cast. See also "Newx".
Memory obtained by this should ONLY be freed with "Safefree".
void Newxc(void* ptr, int nitems, type, cast)
"Newxz"
"safecalloc"
The XSUB-writer's interface to the C "calloc" function. The allocated memory is
zeroed with "memzero". See also "Newx".
Memory obtained by this should ONLY be freed with "Safefree".
void Newxz (void* ptr, int nitems, type)
void* safecalloc(size_t nitems, size_t item_size)
"PERL_MALLOC_WRAP"
This symbol, if defined, indicates that we'd like malloc wrap checks.
"Renew"
"saferealloc"
The XSUB-writer's interface to the C "realloc" function.
Memory obtained by this should ONLY be freed with "Safefree".
void Renew (void* ptr, int nitems, type)
void* saferealloc(void *ptr, size_t size)
"Renewc"
The XSUB-writer's interface to the C "realloc" function, with cast.
Memory obtained by this should ONLY be freed with "Safefree".
void Renewc(void* ptr, int nitems, type, cast)
"Safefree"
The XSUB-writer's interface to the C "free" function.
This should ONLY be used on memory obtained using "Newx" and friends.
void Safefree(void* ptr)
"safesyscalloc"
Safe version of system's calloc()
Malloc_t safesyscalloc(MEM_SIZE elements, MEM_SIZE size)
"safesysfree"
Safe version of system's free()
Free_t safesysfree(Malloc_t where)
"safesysmalloc"
Paranoid version of system's malloc()
Malloc_t safesysmalloc(MEM_SIZE nbytes)
"safesysrealloc"
Paranoid version of system's realloc()
Malloc_t safesysrealloc(Malloc_t where, MEM_SIZE nbytes)
MRO
These functions are related to the method resolution order of perl classes Also see
perlmroapi.
"HvMROMETA"
Described in perlmroapi.
struct mro_meta * HvMROMETA(HV *hv)
"mro_get_from_name"
Returns the previously registered mro with the given "name", or NULL if not
registered. See ""mro_register"".
NOTE: "mro_get_from_name" must be explicitly called as "Perl_mro_get_from_name" with
an "aTHX_" parameter.
const struct mro_alg * Perl_mro_get_from_name(pTHX_ SV *name)
"mro_get_linear_isa"
Returns the mro linearisation for the given stash. By default, this will be whatever
"mro_get_linear_isa_dfs" returns unless some other MRO is in effect for the stash.
The return value is a read-only AV* whose values are string SVs giving class names.
You are responsible for SvREFCNT_inc() on the return value if you plan to store it
anywhere semi-permanently (otherwise it might be deleted out from under you the next
time the cache is invalidated).
AV * mro_get_linear_isa(HV *stash)
"MRO_GET_PRIVATE_DATA"
Described in perlmroapi.
SV* MRO_GET_PRIVATE_DATA(struct mro_meta *const smeta,
const struct mro_alg *const which)
"mro_method_changed_in"
Invalidates method caching on any child classes of the given stash, so that they might
notice the changes in this one.
Ideally, all instances of "PL_sub_generation++" in perl source outside of mro.c should
be replaced by calls to this.
Perl automatically handles most of the common ways a method might be redefined.
However, there are a few ways you could change a method in a stash without the cache
code noticing, in which case you need to call this method afterwards:
1) Directly manipulating the stash HV entries from XS code.
2) Assigning a reference to a readonly scalar constant into a stash entry in order to
create a constant subroutine (like constant.pm does).
This same method is available from pure perl via, mro::method_changed_in(classname).
void mro_method_changed_in(HV *stash)
"mro_register"
Registers a custom mro plugin. See perlmroapi for details on this and other mro
functions.
NOTE: "mro_register" must be explicitly called as "Perl_mro_register" with an "aTHX_"
parameter.
void Perl_mro_register(pTHX_ const struct mro_alg *mro)
"mro_set_mro"
Set "meta" to the value contained in the registered mro plugin whose name is "name".
Croaks if "name" hasn't been registered
NOTE: "mro_set_mro" must be explicitly called as "Perl_mro_set_mro" with an "aTHX_"
parameter.
void Perl_mro_set_mro(pTHX_ struct mro_meta * const meta,
SV * const name)
"mro_set_private_data"
Described in perlmroapi.
NOTE: "mro_set_private_data" must be explicitly called as "Perl_mro_set_private_data"
with an "aTHX_" parameter.
SV * Perl_mro_set_private_data(pTHX_
struct mro_meta * const smeta,
const struct mro_alg * const which,
SV * const data)
Multicall Functions
"dMULTICALL"
Declare local variables for a multicall. See "LIGHTWEIGHT CALLBACKS" in perlcall.
dMULTICALL;
"MULTICALL"
Make a lightweight callback. See "LIGHTWEIGHT CALLBACKS" in perlcall.
MULTICALL;
"POP_MULTICALL"
Closing bracket for a lightweight callback. See "LIGHTWEIGHT CALLBACKS" in perlcall.
POP_MULTICALL;
"PUSH_MULTICALL"
Opening bracket for a lightweight callback. See "LIGHTWEIGHT CALLBACKS" in perlcall.
PUSH_MULTICALL(CV* the_cv);
Numeric Functions
"Atol"
"DEPRECATED!" It is planned to remove "Atol" from a future release of Perl. Do not
use it for new code; remove it from existing code.
Described in perlhacktips.
Atol(const char * nptr)
"Atoul"
"DEPRECATED!" It is planned to remove "Atoul" from a future release of Perl. Do not
use it for new code; remove it from existing code.
Described in perlhacktips.
Atoul(const char * nptr)
"Drand01"
This macro is to be used to generate uniformly distributed random numbers over the
range [0., 1.[. You may have to supply an 'extern double drand48();' in your program
since SunOS 4.1.3 doesn't provide you with anything relevant in its headers. See
"HAS_DRAND48_PROTO".
double Drand01()
"Gconvert"
This preprocessor macro is defined to convert a floating point number to a string
without a trailing decimal point. This emulates the behavior of sprintf("%g"), but is
sometimes much more efficient. If gconvert() is not available, but gcvt() drops the
trailing decimal point, then gcvt() is used. If all else fails, a macro using
sprintf("%g") is used. Arguments for the Gconvert macro are: value, number of digits,
whether trailing zeros should be retained, and the output buffer. The usual values
are:
d_Gconvert='gconvert((x),(n),(t),(b))'
d_Gconvert='gcvt((x),(n),(b))'
d_Gconvert='sprintf((b),"%.*g",(n),(x))'
The last two assume trailing zeros should not be kept.
char * Gconvert(double x, Size_t n, bool t, char * b)
"grok_atoUV"
parse a string, looking for a decimal unsigned integer.
On entry, "pv" points to the beginning of the string; "valptr" points to a UV that
will receive the converted value, if found; "endptr" is either NULL or points to a
variable that points to one byte beyond the point in "pv" that this routine should
examine. If "endptr" is NULL, "pv" is assumed to be NUL-terminated.
Returns FALSE if "pv" doesn't represent a valid unsigned integer value (with no
leading zeros). Otherwise it returns TRUE, and sets *valptr to that value.
If you constrain the portion of "pv" that is looked at by this function (by passing a
non-NULL "endptr"), and if the initial bytes of that portion form a valid value, it
will return TRUE, setting *endptr to the byte following the final digit of the value.
But if there is no constraint at what's looked at, all of "pv" must be valid in order
for TRUE to be returned. *endptr is unchanged from its value on input if FALSE is
returned;
The only characters this accepts are the decimal digits '0'..'9'.
As opposed to atoi(3) or strtol(3), "grok_atoUV" does NOT allow optional leading
whitespace, nor negative inputs. If such features are required, the calling code
needs to explicitly implement those.
Note that this function returns FALSE for inputs that would overflow a UV, or have
leading zeros. Thus a single 0 is accepted, but not 00 nor 01, 002, etc.
Background: "atoi" has severe problems with illegal inputs, it cannot be used for
incremental parsing, and therefore should be avoided "atoi" and "strtol" are also
affected by locale settings, which can also be seen as a bug (global state controlled
by user environment).
bool grok_atoUV(const char *pv, UV *valptr, const char **endptr)
"grok_bin"
converts a string representing a binary number to numeric form.
On entry "start" and *len_p give the string to scan, *flags gives conversion flags,
and "result" should be "NULL" or a pointer to an NV. The scan stops at the end of the
string, or at just before the first invalid character. Unless
"PERL_SCAN_SILENT_ILLDIGIT" is set in *flags, encountering an invalid character
(except NUL) will also trigger a warning. On return *len_p is set to the length of
the scanned string, and *flags gives output flags.
If the value is <= "UV_MAX" it is returned as a UV, the output flags are clear, and
nothing is written to *result. If the value is > "UV_MAX", "grok_bin" returns
"UV_MAX", sets "PERL_SCAN_GREATER_THAN_UV_MAX" in the output flags, and writes an
approximation of the correct value into *result (which is an NV; or the approximation
is discarded if "result" is NULL).
The binary number may optionally be prefixed with "0b" or "b" unless
"PERL_SCAN_DISALLOW_PREFIX" is set in *flags on entry.
If "PERL_SCAN_ALLOW_UNDERSCORES" is set in *flags then any or all pairs of digits may
be separated from each other by a single underscore; also a single leading underscore
is accepted.
UV grok_bin(const char *start, STRLEN *len_p, I32 *flags,
NV *result)
"grok_hex"
converts a string representing a hex number to numeric form.
On entry "start" and *len_p give the string to scan, *flags gives conversion flags,
and "result" should be "NULL" or a pointer to an NV. The scan stops at the end of the
string, or at just before the first invalid character. Unless
"PERL_SCAN_SILENT_ILLDIGIT" is set in *flags, encountering an invalid character
(except NUL) will also trigger a warning. On return *len_p is set to the length of
the scanned string, and *flags gives output flags.
If the value is <= "UV_MAX" it is returned as a UV, the output flags are clear, and
nothing is written to *result. If the value is > "UV_MAX", "grok_hex" returns
"UV_MAX", sets "PERL_SCAN_GREATER_THAN_UV_MAX" in the output flags, and writes an
approximation of the correct value into *result (which is an NV; or the approximation
is discarded if "result" is NULL).
The hex number may optionally be prefixed with "0x" or "x" unless
"PERL_SCAN_DISALLOW_PREFIX" is set in *flags on entry.
If "PERL_SCAN_ALLOW_UNDERSCORES" is set in *flags then any or all pairs of digits may
be separated from each other by a single underscore; also a single leading underscore
is accepted.
UV grok_hex(const char *start, STRLEN *len_p, I32 *flags,
NV *result)
"grok_infnan"
Helper for grok_number(), accepts various ways of spelling "infinity" or "not a
number", and returns one of the following flag combinations:
IS_NUMBER_INFINITY
IS_NUMBER_NAN
IS_NUMBER_INFINITY | IS_NUMBER_NEG
IS_NUMBER_NAN | IS_NUMBER_NEG
0
possibly |-ed with "IS_NUMBER_TRAILING".
If an infinity or a not-a-number is recognized, *sp will point to one byte past the
end of the recognized string. If the recognition fails, zero is returned, and *sp
will not move.
int grok_infnan(const char **sp, const char *send)
"grok_number"
Identical to grok_number_flags() with "flags" set to zero.
int grok_number(const char *pv, STRLEN len, UV *valuep)
"grok_number_flags"
Recognise (or not) a number. The type of the number is returned (0 if unrecognised),
otherwise it is a bit-ORed combination of "IS_NUMBER_IN_UV",
"IS_NUMBER_GREATER_THAN_UV_MAX", "IS_NUMBER_NOT_INT", "IS_NUMBER_NEG",
"IS_NUMBER_INFINITY", "IS_NUMBER_NAN" (defined in perl.h).
If the value of the number can fit in a UV, it is returned in *valuep.
"IS_NUMBER_IN_UV" will be set to indicate that *valuep is valid, "IS_NUMBER_IN_UV"
will never be set unless *valuep is valid, but *valuep may have been assigned to
during processing even though "IS_NUMBER_IN_UV" is not set on return. If "valuep" is
"NULL", "IS_NUMBER_IN_UV" will be set for the same cases as when "valuep" is
non-"NULL", but no actual assignment (or SEGV) will occur.
"IS_NUMBER_NOT_INT" will be set with "IS_NUMBER_IN_UV" if trailing decimals were seen
(in which case *valuep gives the true value truncated to an integer), and
"IS_NUMBER_NEG" if the number is negative (in which case *valuep holds the absolute
value). "IS_NUMBER_IN_UV" is not set if "e" notation was used or the number is larger
than a UV.
"flags" allows only "PERL_SCAN_TRAILING", which allows for trailing non-numeric text
on an otherwise successful grok, setting "IS_NUMBER_TRAILING" on the result.
int grok_number_flags(const char *pv, STRLEN len, UV *valuep,
U32 flags)
"GROK_NUMERIC_RADIX"
A synonym for "grok_numeric_radix"
bool GROK_NUMERIC_RADIX(NN const char **sp, NN const char *send)
"grok_numeric_radix"
Scan and skip for a numeric decimal separator (radix).
bool grok_numeric_radix(const char **sp, const char *send)
"grok_oct"
converts a string representing an octal number to numeric form.
On entry "start" and *len_p give the string to scan, *flags gives conversion flags,
and "result" should be "NULL" or a pointer to an NV. The scan stops at the end of the
string, or at just before the first invalid character. Unless
"PERL_SCAN_SILENT_ILLDIGIT" is set in *flags, encountering an invalid character
(except NUL) will also trigger a warning. On return *len_p is set to the length of
the scanned string, and *flags gives output flags.
If the value is <= "UV_MAX" it is returned as a UV, the output flags are clear, and
nothing is written to *result. If the value is > "UV_MAX", "grok_oct" returns
"UV_MAX", sets "PERL_SCAN_GREATER_THAN_UV_MAX" in the output flags, and writes an
approximation of the correct value into *result (which is an NV; or the approximation
is discarded if "result" is NULL).
If "PERL_SCAN_ALLOW_UNDERSCORES" is set in *flags then any or all pairs of digits may
be separated from each other by a single underscore; also a single leading underscore
is accepted.
The "PERL_SCAN_DISALLOW_PREFIX" flag is always treated as being set for this function.
UV grok_oct(const char *start, STRLEN *len_p, I32 *flags,
NV *result)
"isinfnan"
Perl_isinfnan() is a utility function that returns true if the NV argument is either
an infinity or a "NaN", false otherwise. To test in more detail, use Perl_isinf() and
Perl_isnan().
This is also the logical inverse of Perl_isfinite().
bool isinfnan(NV nv)
"my_atof"
"atof"(3), but properly works with Perl locale handling, accepting a dot radix
character always, but also the current locale's radix character if and only if called
from within the lexical scope of a Perl "use locale" statement.
N.B. "s" must be NUL terminated.
NV my_atof(const char *s)
"my_strtod"
This function is equivalent to the libc strtod() function, and is available even on
platforms that lack plain strtod(). Its return value is the best available precision
depending on platform capabilities and Configure options.
It properly handles the locale radix character, meaning it expects a dot except when
called from within the scope of "use locale", in which case the radix character should
be that specified by the current locale.
The synonym Strtod() may be used instead.
NV my_strtod(const char * const s, char **e)
"PERL_ABS"
Typeless "abs" or "fabs", etc. (The usage below indicates it is for integers, but it
works for any type.) Use instead of these, since the C library ones force their
argument to be what it is expecting, potentially leading to disaster. But also beware
that this evaluates its argument twice, so no "x++".
int PERL_ABS(int x)
"Perl_acos"
"Perl_asin"
"Perl_atan"
"Perl_atan2"
"Perl_ceil"
"Perl_cos"
"Perl_cosh"
"Perl_exp"
"Perl_floor"
"Perl_fmod"
"Perl_frexp"
"Perl_isfinite"
"Perl_isinf"
"Perl_isnan"
"Perl_ldexp"
"Perl_log"
"Perl_log10"
"Perl_modf"
"Perl_pow"
"Perl_sin"
"Perl_sinh"
"Perl_sqrt"
"Perl_tan"
"Perl_tanh"
These perform the corresponding mathematical operation on the operand(s), using the
libc function designed for the task that has just enough precision for an NV on this
platform. If no such function with sufficient precision exists, the highest precision
one available is used.
NV Perl_acos (NV x)
NV Perl_asin (NV x)
NV Perl_atan (NV x)
NV Perl_atan2 (NV x, NV y)
NV Perl_ceil (NV x)
NV Perl_cos (NV x)
NV Perl_cosh (NV x)
NV Perl_exp (NV x)
NV Perl_floor (NV x)
NV Perl_fmod (NV x, NV y)
NV Perl_frexp (NV x, int *exp)
IV Perl_isfinite(NV x)
IV Perl_isinf (NV x)
IV Perl_isnan (NV x)
NV Perl_ldexp (NV x, int exp)
NV Perl_log (NV x)
NV Perl_log10 (NV x)
NV Perl_modf (NV x, NV *iptr)
NV Perl_pow (NV x, NV y)
NV Perl_sin (NV x)
NV Perl_sinh (NV x)
NV Perl_sqrt (NV x)
NV Perl_tan (NV x)
NV Perl_tanh (NV x)
"Perl_signbit"
NOTE: "Perl_signbit" is experimental and may change or be removed without notice.
Return a non-zero integer if the sign bit on an NV is set, and 0 if it is not.
If Configure detects this system has a signbit() that will work with our NVs, then we
just use it via the "#define" in perl.h. Otherwise, fall back on this implementation.
The main use of this function is catching -0.0.
"Configure" notes: This function is called 'Perl_signbit' instead of a plain
'signbit' because it is easy to imagine a system having a signbit() function or macro
that doesn't happen to work with our particular choice of NVs. We shouldn't just
re-"#define" "signbit" as "Perl_signbit" and expect the standard system headers to be
happy. Also, this is a no-context function (no "pTHX_") because Perl_signbit() is
usually re-"#defined" in perl.h as a simple macro call to the system's signbit().
Users should just always call Perl_signbit().
int Perl_signbit(NV f)
"PL_hexdigit"
This array, indexed by an integer, converts that value into the character that
represents it. For example, if the input is 8, the return will be a string whose
first character is '8'. What is actually returned is a pointer into a string. All
you are interested in is the first character of that string. To get uppercase letters
(for the values 10..15), add 16 to the index. Hence, "PL_hexdigit[11]" is 'b', and
"PL_hexdigit[11+16]" is 'B'. Adding 16 to an index whose representation is '0'..'9'
yields the same as not adding 16. Indices outside the range 0..31 result in (bad)
undedefined behavior.
"READ_XDIGIT"
Returns the value of an ASCII-range hex digit and advances the string pointer.
Behaviour is only well defined when isXDIGIT(*str) is true.
U8 READ_XDIGIT(char str*)
"scan_bin"
For backwards compatibility. Use "grok_bin" instead.
NV scan_bin(const char *start, STRLEN len, STRLEN *retlen)
"scan_hex"
For backwards compatibility. Use "grok_hex" instead.
NV scan_hex(const char *start, STRLEN len, STRLEN *retlen)
"scan_oct"
For backwards compatibility. Use "grok_oct" instead.
NV scan_oct(const char *start, STRLEN len, STRLEN *retlen)
"seedDrand01"
This symbol defines the macro to be used in seeding the random number generator (see
"Drand01").
void seedDrand01(Rand_seed_t x)
"Strtod"
This is a synonym for "my_strtod".
NV Strtod(NN const char * const s, NULLOK char ** e)
"Strtol"
Platform and configuration independent "strtol". This expands to the appropriate
"strotol"-like function based on the platform and Configure options>. For example it
could expand to "strtoll" or "strtoq" instead of "strtol".
NV Strtol(NN const char * const s, NULLOK char ** e, int base)
"Strtoul"
Platform and configuration independent "strtoul". This expands to the appropriate
"strotoul"-like function based on the platform and Configure options>. For example it
could expand to "strtoull" or "strtouq" instead of "strtoul".
NV Strtoul(NN const char * const s, NULLOK char ** e, int base)
Optrees
"alloccopstash"
NOTE: "alloccopstash" is experimental and may change or be removed without notice.
Available only under threaded builds, this function allocates an entry in
"PL_stashpad" for the stash passed to it.
PADOFFSET alloccopstash(HV *hv)
"BINOP"
Described in perlguts.
"block_end"
Handles compile-time scope exit. "floor" is the savestack index returned by
"block_start", and "seq" is the body of the block. Returns the block, possibly
modified.
OP * block_end(I32 floor, OP *seq)
"block_start"
Handles compile-time scope entry. Arranges for hints to be restored on block exit and
also handles pad sequence numbers to make lexical variables scope right. Returns a
savestack index for use with "block_end".
int block_start(int full)
"ck_entersub_args_list"
Performs the default fixup of the arguments part of an "entersub" op tree. This
consists of applying list context to each of the argument ops. This is the standard
treatment used on a call marked with "&", or a method call, or a call through a
subroutine reference, or any other call where the callee can't be identified at
compile time, or a call where the callee has no prototype.
OP * ck_entersub_args_list(OP *entersubop)
"ck_entersub_args_proto"
Performs the fixup of the arguments part of an "entersub" op tree based on a
subroutine prototype. This makes various modifications to the argument ops, from
applying context up to inserting "refgen" ops, and checking the number and syntactic
types of arguments, as directed by the prototype. This is the standard treatment used
on a subroutine call, not marked with "&", where the callee can be identified at
compile time and has a prototype.
"protosv" supplies the subroutine prototype to be applied to the call. It may be a
normal defined scalar, of which the string value will be used. Alternatively, for
convenience, it may be a subroutine object (a "CV*" that has been cast to "SV*") which
has a prototype. The prototype supplied, in whichever form, does not need to match
the actual callee referenced by the op tree.
If the argument ops disagree with the prototype, for example by having an unacceptable
number of arguments, a valid op tree is returned anyway. The error is reflected in
the parser state, normally resulting in a single exception at the top level of parsing
which covers all the compilation errors that occurred. In the error message, the
callee is referred to by the name defined by the "namegv" parameter.
OP * ck_entersub_args_proto(OP *entersubop, GV *namegv,
SV *protosv)
"ck_entersub_args_proto_or_list"
Performs the fixup of the arguments part of an "entersub" op tree either based on a
subroutine prototype or using default list-context processing. This is the standard
treatment used on a subroutine call, not marked with "&", where the callee can be
identified at compile time.
"protosv" supplies the subroutine prototype to be applied to the call, or indicates
that there is no prototype. It may be a normal scalar, in which case if it is defined
then the string value will be used as a prototype, and if it is undefined then there
is no prototype. Alternatively, for convenience, it may be a subroutine object (a
"CV*" that has been cast to "SV*"), of which the prototype will be used if it has one.
The prototype (or lack thereof) supplied, in whichever form, does not need to match
the actual callee referenced by the op tree.
If the argument ops disagree with the prototype, for example by having an unacceptable
number of arguments, a valid op tree is returned anyway. The error is reflected in
the parser state, normally resulting in a single exception at the top level of parsing
which covers all the compilation errors that occurred. In the error message, the
callee is referred to by the name defined by the "namegv" parameter.
OP * ck_entersub_args_proto_or_list(OP *entersubop, GV *namegv,
SV *protosv)
"cv_const_sv"
If "cv" is a constant sub eligible for inlining, returns the constant value returned
by the sub. Otherwise, returns "NULL".
Constant subs can be created with "newCONSTSUB" or as described in "Constant
Functions" in perlsub.
SV * cv_const_sv(const CV * const cv)
"cv_get_call_checker"
The original form of "cv_get_call_checker_flags", which does not return checker flags.
When using a checker function returned by this function, it is only safe to call it
with a genuine GV as its "namegv" argument.
void cv_get_call_checker(CV *cv, Perl_call_checker *ckfun_p,
SV **ckobj_p)
"cv_get_call_checker_flags"
Retrieves the function that will be used to fix up a call to "cv". Specifically, the
function is applied to an "entersub" op tree for a subroutine call, not marked with
"&", where the callee can be identified at compile time as "cv".
The C-level function pointer is returned in *ckfun_p, an SV argument for it is
returned in *ckobj_p, and control flags are returned in *ckflags_p. The function is
intended to be called in this manner:
entersubop = (*ckfun_p)(aTHX_ entersubop, namegv, (*ckobj_p));
In this call, "entersubop" is a pointer to the "entersub" op, which may be replaced by
the check function, and "namegv" supplies the name that should be used by the check
function to refer to the callee of the "entersub" op if it needs to emit any
diagnostics. It is permitted to apply the check function in non-standard situations,
such as to a call to a different subroutine or to a method call.
"namegv" may not actually be a GV. If the "CALL_CHECKER_REQUIRE_GV" bit is clear in
*ckflags_p, it is permitted to pass a CV or other SV instead, anything that can be
used as the first argument to "cv_name". If the "CALL_CHECKER_REQUIRE_GV" bit is set
in *ckflags_p then the check function requires "namegv" to be a genuine GV.
By default, the check function is Perl_ck_entersub_args_proto_or_list, the SV
parameter is "cv" itself, and the "CALL_CHECKER_REQUIRE_GV" flag is clear. This
implements standard prototype processing. It can be changed, for a particular
subroutine, by "cv_set_call_checker_flags".
If the "CALL_CHECKER_REQUIRE_GV" bit is set in "gflags" then it indicates that the
caller only knows about the genuine GV version of "namegv", and accordingly the
corresponding bit will always be set in *ckflags_p, regardless of the check function's
recorded requirements. If the "CALL_CHECKER_REQUIRE_GV" bit is clear in "gflags" then
it indicates the caller knows about the possibility of passing something other than a
GV as "namegv", and accordingly the corresponding bit may be either set or clear in
*ckflags_p, indicating the check function's recorded requirements.
"gflags" is a bitset passed into "cv_get_call_checker_flags", in which only the
"CALL_CHECKER_REQUIRE_GV" bit currently has a defined meaning (for which see above).
All other bits should be clear.
void cv_get_call_checker_flags(CV *cv, U32 gflags,
Perl_call_checker *ckfun_p,
SV **ckobj_p, U32 *ckflags_p)
"cv_set_call_checker"
The original form of "cv_set_call_checker_flags", which passes it the
"CALL_CHECKER_REQUIRE_GV" flag for backward-compatibility. The effect of that flag
setting is that the check function is guaranteed to get a genuine GV as its "namegv"
argument.
void cv_set_call_checker(CV *cv, Perl_call_checker ckfun,
SV *ckobj)
"cv_set_call_checker_flags"
Sets the function that will be used to fix up a call to "cv". Specifically, the
function is applied to an "entersub" op tree for a subroutine call, not marked with
"&", where the callee can be identified at compile time as "cv".
The C-level function pointer is supplied in "ckfun", an SV argument for it is supplied
in "ckobj", and control flags are supplied in "ckflags". The function should be
defined like this:
STATIC OP * ckfun(pTHX_ OP *op, GV *namegv, SV *ckobj)
It is intended to be called in this manner:
entersubop = ckfun(aTHX_ entersubop, namegv, ckobj);
In this call, "entersubop" is a pointer to the "entersub" op, which may be replaced by
the check function, and "namegv" supplies the name that should be used by the check
function to refer to the callee of the "entersub" op if it needs to emit any
diagnostics. It is permitted to apply the check function in non-standard situations,
such as to a call to a different subroutine or to a method call.
"namegv" may not actually be a GV. For efficiency, perl may pass a CV or other SV
instead. Whatever is passed can be used as the first argument to "cv_name". You can
force perl to pass a GV by including "CALL_CHECKER_REQUIRE_GV" in the "ckflags".
"ckflags" is a bitset, in which only the "CALL_CHECKER_REQUIRE_GV" bit currently has a
defined meaning (for which see above). All other bits should be clear.
The current setting for a particular CV can be retrieved by
"cv_get_call_checker_flags".
void cv_set_call_checker_flags(CV *cv, Perl_call_checker ckfun,
SV *ckobj, U32 ckflags)
"finalize_optree"
This function finalizes the optree. Should be called directly after the complete
optree is built. It does some additional checking which can't be done in the normal
"ck_"xxx functions and makes the tree thread-safe.
void finalize_optree(OP *o)
"forbid_outofblock_ops"
NOTE: "forbid_outofblock_ops" is experimental and may change or be removed without
notice.
Checks an optree that implements a block, to ensure there are no control-flow ops that
attempt to leave the block. Any "OP_RETURN" is forbidden, as is any "OP_GOTO". Loops
are analysed, so any LOOPEX op ("OP_NEXT", "OP_LAST" or "OP_REDO") that affects a loop
that contains it within the block are permitted, but those that do not are forbidden.
If any of these forbidden constructions are detected, an exception is thrown by using
the op name and the blockname argument to construct a suitable message.
This function alone is not sufficient to ensure the optree does not perform any of
these forbidden activities during runtime, as it might call a different function that
performs a non-local LOOPEX, or a string-eval() that performs a "goto", or various
other things. It is intended purely as a compile-time check for those that could be
detected statically. Additional runtime checks may be required depending on the
circumstance it is used for.
Note currently that all "OP_GOTO" ops are forbidden, even in cases where they might
otherwise be safe to execute. This may be permitted in a later version.
void forbid_outofblock_ops(OP *o, const char *blockname)
"LINKLIST"
Given the root of an optree, link the tree in execution order using the "op_next"
pointers and return the first op executed. If this has already been done, it will not
be redone, and "o->op_next" will be returned. If "o->op_next" is not already set, "o"
should be at least an "UNOP".
OP* LINKLIST(OP *o)
"LISTOP"
Described in perlguts.
"LOGOP"
Described in perlguts.
"LOOP"
Described in perlguts.
"newANONATTRSUB"
Construct a nameless (anonymous) Perl subroutine, also performing some surrounding
jobs.
This is the same as ""newATTRSUB_x"" in perlintern with its "o_is_gv" parameter set to
FALSE, and its "o" parameter to NULL. For more details, see ""newATTRSUB_x"" in
perlintern.
OP * newANONATTRSUB(I32 floor, OP *proto, OP *attrs, OP *block)
"newANONHASH"
Constructs, checks, and returns an anonymous hash op.
OP * newANONHASH(OP *o)
"newANONLIST"
Constructs, checks, and returns an anonymous list op.
OP * newANONLIST(OP *o)
"newANONSUB"
Construct a nameless (anonymous) Perl subroutine without attributes, also performing
some surrounding jobs.
This is the same as ""newATTRSUB_x"" in perlintern with its "o_is_gv" parameter set to
FALSE, and its "o" and "attrs" parameters to NULL. For more details, see
""newATTRSUB_x"" in perlintern.
OP * newANONSUB(I32 floor, OP *proto, OP *block)
"newARGDEFELEMOP"
Constructs and returns a new "OP_ARGDEFELEM" op which provides a defaulting expression
given by "expr" for the signature parameter at the index given by "argindex". The
expression optree is consumed by this function and becomes part of the returned
optree.
OP * newARGDEFELEMOP(I32 flags, OP *expr, I32 argindex)
"newASSIGNOP"
Constructs, checks, and returns an assignment op. "left" and "right" supply the
parameters of the assignment; they are consumed by this function and become part of
the constructed op tree.
If "optype" is "OP_ANDASSIGN", "OP_ORASSIGN", or "OP_DORASSIGN", then a suitable
conditional optree is constructed. If "optype" is the opcode of a binary operator,
such as "OP_BIT_OR", then an op is constructed that performs the binary operation and
assigns the result to the left argument. Either way, if "optype" is non-zero then
"flags" has no effect.
If "optype" is zero, then a plain scalar or list assignment is constructed. Which
type of assignment it is is automatically determined. "flags" gives the eight bits of
"op_flags", except that "OPf_KIDS" will be set automatically, and, shifted up eight
bits, the eight bits of "op_private", except that the bit with value 1 or 2 is
automatically set as required.
OP * newASSIGNOP(I32 flags, OP *left, I32 optype, OP *right)
"newATTRSUB"
Construct a Perl subroutine, also performing some surrounding jobs, returning a
pointer to the constructed subroutine.
This is the same as ""newATTRSUB_x"" in perlintern with its "o_is_gv" parameter set to
FALSE. This means that if "o" is null, the new sub will be anonymous; otherwise the
name will be derived from "o" in the way described (as with all other details) in
""newATTRSUB_x"" in perlintern.
CV * newATTRSUB(I32 floor, OP *o, OP *proto, OP *attrs,
OP *block)
"newAVREF"
Constructs, checks, and returns an arrary reference op.
OP * newAVREF(OP *o)
"newBINOP"
Constructs, checks, and returns an op of any binary type. "type" is the opcode.
"flags" gives the eight bits of "op_flags", except that "OPf_KIDS" will be set
automatically, and, shifted up eight bits, the eight bits of "op_private", except that
the bit with value 1 or 2 is automatically set as required. "first" and "last" supply
up to two ops to be the direct children of the binary op; they are consumed by this
function and become part of the constructed op tree.
OP * newBINOP(I32 type, I32 flags, OP *first, OP *last)
"newCONDOP"
Constructs, checks, and returns a conditional-expression ("cond_expr") op. "flags"
gives the eight bits of "op_flags", except that "OPf_KIDS" will be set automatically,
and, shifted up eight bits, the eight bits of "op_private", except that the bit with
value 1 is automatically set. "first" supplies the expression selecting between the
two branches, and "trueop" and "falseop" supply the branches; they are consumed by
this function and become part of the constructed op tree.
OP * newCONDOP(I32 flags, OP *first, OP *trueop, OP *falseop)
"newCONSTSUB"
"newCONSTSUB_flags"
Construct a constant subroutine, also performing some surrounding jobs. A scalar
constant-valued subroutine is eligible for inlining at compile-time, and in Perl code
can be created by "sub FOO () { 123 }". Other kinds of constant subroutine have other
treatment.
The subroutine will have an empty prototype and will ignore any arguments when called.
Its constant behaviour is determined by "sv". If "sv" is null, the subroutine will
yield an empty list. If "sv" points to a scalar, the subroutine will always yield
that scalar. If "sv" points to an array, the subroutine will always yield a list of
the elements of that array in list context, or the number of elements in the array in
scalar context. This function takes ownership of one counted reference to the scalar
or array, and will arrange for the object to live as long as the subroutine does. If
"sv" points to a scalar then the inlining assumes that the value of the scalar will
never change, so the caller must ensure that the scalar is not subsequently written
to. If "sv" points to an array then no such assumption is made, so it is ostensibly
safe to mutate the array or its elements, but whether this is really supported has not
been determined.
The subroutine will have "CvFILE" set according to "PL_curcop". Other aspects of the
subroutine will be left in their default state. The caller is free to mutate the
subroutine beyond its initial state after this function has returned.
If "name" is null then the subroutine will be anonymous, with its "CvGV" referring to
an "__ANON__" glob. If "name" is non-null then the subroutine will be named
accordingly, referenced by the appropriate glob.
"name" is a string, giving a sigilless symbol name. For "/newCONSTSUB", "name" is
NUL-terminated, interpreted as Latin-1.
For "/newCONSTSUB_flags", "name" has length "len" bytes, hence may contain embedded
NULs. It is interpreted as UTF-8 if "flags" has the "SVf_UTF8" bit set, and Latin-1
otherwise. "flags" should not have bits set other than "SVf_UTF8".
The name may be either qualified or unqualified. If the name is unqualified then it
defaults to being in the stash specified by "stash" if that is non-null, or to
"PL_curstash" if "stash" is null. The symbol is always added to the stash if
necessary, with "GV_ADDMULTI" semantics.
If there is already a subroutine of the specified name, then the new sub will replace
the existing one in the glob. A warning may be generated about the redefinition.
If the subroutine has one of a few special names, such as "BEGIN" or "END", then it
will be claimed by the appropriate queue for automatic running of phase-related
subroutines. In this case the relevant glob will be left not containing any
subroutine, even if it did contain one before. Execution of the subroutine will
likely be a no-op, unless "sv" was a tied array or the caller modified the subroutine
in some interesting way before it was executed. In the case of "BEGIN", the treatment
is buggy: the sub will be executed when only half built, and may be deleted
prematurely, possibly causing a crash.
The function returns a pointer to the constructed subroutine. If the sub is anonymous
then ownership of one counted reference to the subroutine is transferred to the
caller. If the sub is named then the caller does not get ownership of a reference.
In most such cases, where the sub has a non-phase name, the sub will be alive at the
point it is returned by virtue of being contained in the glob that names it. A phase-
named subroutine will usually be alive by virtue of the reference owned by the phase's
automatic run queue. A "BEGIN" subroutine may have been destroyed already by the time
this function returns, but currently bugs occur in that case before the caller gets
control. It is the caller's responsibility to ensure that it knows which of these
situations applies.
CV * newCONSTSUB (HV *stash, const char *name, SV *sv)
CV * newCONSTSUB_flags(HV *stash, const char *name, STRLEN len,
U32 flags, SV *sv)
"newCVREF"
Constructs, checks, and returns a code reference op.
OP * newCVREF(I32 flags, OP *o)
"newDEFEROP"
NOTE: "newDEFEROP" is experimental and may change or be removed without notice.
Constructs and returns a deferred-block statement that implements the "defer"
semantics. The "block" optree is consumed by this function and becomes part of the
returned optree.
The "flags" argument carries additional flags to set on the returned op, including the
"op_private" field.
OP * newDEFEROP(I32 flags, OP *block)
"newDEFSVOP"
Constructs and returns an op to access $_.
OP * newDEFSVOP()
"newFOROP"
Constructs, checks, and returns an op tree expressing a "foreach" loop (iteration
through a list of values). This is a heavyweight loop, with structure that allows
exiting the loop by "last" and suchlike.
"sv" optionally supplies the variable(s) that will be aliased to each item in turn; if
null, it defaults to $_. "expr" supplies the list of values to iterate over. "block"
supplies the main body of the loop, and "cont" optionally supplies a "continue" block
that operates as a second half of the body. All of these optree inputs are consumed
by this function and become part of the constructed op tree.
"flags" gives the eight bits of "op_flags" for the "leaveloop" op and, shifted up
eight bits, the eight bits of "op_private" for the "leaveloop" op, except that (in
both cases) some bits will be set automatically.
OP * newFOROP(I32 flags, OP *sv, OP *expr, OP *block, OP *cont)
"newGIVENOP"
Constructs, checks, and returns an op tree expressing a "given" block. "cond"
supplies the expression to whose value $_ will be locally aliased, and "block"
supplies the body of the "given" construct; they are consumed by this function and
become part of the constructed op tree. "defsv_off" must be zero (it used to identity
the pad slot of lexical $_).
OP * newGIVENOP(OP *cond, OP *block, PADOFFSET defsv_off)
"newGVOP"
Constructs, checks, and returns an op of any type that involves an embedded reference
to a GV. "type" is the opcode. "flags" gives the eight bits of "op_flags". "gv"
identifies the GV that the op should reference; calling this function does not
transfer ownership of any reference to it.
OP * newGVOP(I32 type, I32 flags, GV *gv)
"newGVREF"
Constructs, checks, and returns a glob reference op.
OP * newGVREF(I32 type, OP *o)
"newHVREF"
Constructs, checks, and returns a hash reference op.
OP * newHVREF(OP *o)
"newLISTOP"
Constructs, checks, and returns an op of any list type. "type" is the opcode.
"flags" gives the eight bits of "op_flags", except that "OPf_KIDS" will be set
automatically if required. "first" and "last" supply up to two ops to be direct
children of the list op; they are consumed by this function and become part of the
constructed op tree.
For most list operators, the check function expects all the kid ops to be present
already, so calling "newLISTOP(OP_JOIN, ...)" (e.g.) is not appropriate. What you
want to do in that case is create an op of type "OP_LIST", append more children to it,
and then call "op_convert_list". See "op_convert_list" for more information.
If a compiletime-known fixed list of child ops is required, the "newLISTOPn" function
can be used as a convenient shortcut, avoiding the need to create a temporary plain
"OP_LIST" in a new variable.
OP * newLISTOP(I32 type, I32 flags, OP *first, OP *last)
"newLISTOPn"
Constructs, checks, and returns an op of any list type. "type" is the opcode.
"flags" gives the eight bits of "op_flags", except that "OPf_KIDS" will be set
automatically if required. The variable number of arguments after "flags" must all be
OP pointers, terminated by a final "NULL" pointer. These will all be consumed as
direct children of the list op and become part of the constructed op tree.
Do not forget to end the arguments list with a "NULL" pointer.
This function is useful as a shortcut to performing the sequence of newLISTOP(),
op_append_elem() on each element and final op_convert_list() in the case where a
compiletime-known fixed sequence of child ops is required. If a variable number of
elements are required, or for splicing in an entire sub-list of child ops, see instead
"newLISTOP" and "op_convert_list".
OP * newLISTOPn(I32 type, I32 flags, ...)
"newLOGOP"
Constructs, checks, and returns a logical (flow control) op. "type" is the opcode.
"flags" gives the eight bits of "op_flags", except that "OPf_KIDS" will be set
automatically, and, shifted up eight bits, the eight bits of "op_private", except that
the bit with value 1 is automatically set. "first" supplies the expression
controlling the flow, and "other" supplies the side (alternate) chain of ops; they are
consumed by this function and become part of the constructed op tree.
OP * newLOGOP(I32 optype, I32 flags, OP *first, OP *other)
"newLOOPEX"
Constructs, checks, and returns a loop-exiting op (such as "goto" or "last"). "type"
is the opcode. "label" supplies the parameter determining the target of the op; it is
consumed by this function and becomes part of the constructed op tree.
OP * newLOOPEX(I32 type, OP *label)
"newLOOPOP"
Constructs, checks, and returns an op tree expressing a loop. This is only a loop in
the control flow through the op tree; it does not have the heavyweight loop structure
that allows exiting the loop by "last" and suchlike. "flags" gives the eight bits of
"op_flags" for the top-level op, except that some bits will be set automatically as
required. "expr" supplies the expression controlling loop iteration, and "block"
supplies the body of the loop; they are consumed by this function and become part of
the constructed op tree. "debuggable" is currently unused and should always be 1.
OP * newLOOPOP(I32 flags, I32 debuggable, OP *expr, OP *block)
"newMETHOP"
Constructs, checks, and returns an op of method type with a method name evaluated at
runtime. "type" is the opcode. "flags" gives the eight bits of "op_flags", except
that "OPf_KIDS" will be set automatically, and, shifted up eight bits, the eight bits
of "op_private", except that the bit with value 1 is automatically set.
"dynamic_meth" supplies an op which evaluates method name; it is consumed by this
function and become part of the constructed op tree. Supported optypes: "OP_METHOD".
OP * newMETHOP(I32 type, I32 flags, OP *dynamic_meth)
"newMETHOP_named"
Constructs, checks, and returns an op of method type with a constant method name.
"type" is the opcode. "flags" gives the eight bits of "op_flags", and, shifted up
eight bits, the eight bits of "op_private". "const_meth" supplies a constant method
name; it must be a shared COW string. Supported optypes: "OP_METHOD_NAMED".
OP * newMETHOP_named(I32 type, I32 flags, SV * const_meth)
"newNULLLIST"
Constructs, checks, and returns a new "stub" op, which represents an empty list
expression.
OP * newNULLLIST()
"newOP"
Constructs, checks, and returns an op of any base type (any type that has no extra
fields). "type" is the opcode. "flags" gives the eight bits of "op_flags", and,
shifted up eight bits, the eight bits of "op_private".
OP * newOP(I32 optype, I32 flags)
"newPADOP"
Constructs, checks, and returns an op of any type that involves a reference to a pad
element. "type" is the opcode. "flags" gives the eight bits of "op_flags". A pad
slot is automatically allocated, and is populated with "sv"; this function takes
ownership of one reference to it.
This function only exists if Perl has been compiled to use ithreads.
OP * newPADOP(I32 type, I32 flags, SV *sv)
"newPMOP"
Constructs, checks, and returns an op of any pattern matching type. "type" is the
opcode. "flags" gives the eight bits of "op_flags" and, shifted up eight bits, the
eight bits of "op_private".
OP * newPMOP(I32 type, I32 flags)
"newPVOP"
Constructs, checks, and returns an op of any type that involves an embedded C-level
pointer (PV). "type" is the opcode. "flags" gives the eight bits of "op_flags".
"pv" supplies the C-level pointer. Depending on the op type, the memory referenced by
"pv" may be freed when the op is destroyed. If the op is of a freeing type, "pv" must
have been allocated using "PerlMemShared_malloc".
OP * newPVOP(I32 type, I32 flags, char *pv)
"newRANGE"
Constructs and returns a "range" op, with subordinate "flip" and "flop" ops. "flags"
gives the eight bits of "op_flags" for the "flip" op and, shifted up eight bits, the
eight bits of "op_private" for both the "flip" and "range" ops, except that the bit
with value 1 is automatically set. "left" and "right" supply the expressions
controlling the endpoints of the range; they are consumed by this function and become
part of the constructed op tree.
OP * newRANGE(I32 flags, OP *left, OP *right)
"newSLICEOP"
Constructs, checks, and returns an "lslice" (list slice) op. "flags" gives the eight
bits of "op_flags", except that "OPf_KIDS" will be set automatically, and, shifted up
eight bits, the eight bits of "op_private", except that the bit with value 1 or 2 is
automatically set as required. "listval" and "subscript" supply the parameters of the
slice; they are consumed by this function and become part of the constructed op tree.
OP * newSLICEOP(I32 flags, OP *subscript, OP *listop)
"newSTATEOP"
Constructs a state op (COP). The state op is normally a "nextstate" op, but will be a
"dbstate" op if debugging is enabled for currently-compiled code. The state op is
populated from "PL_curcop" (or "PL_compiling"). If "label" is non-null, it supplies
the name of a label to attach to the state op; this function takes ownership of the
memory pointed at by "label", and will free it. "flags" gives the eight bits of
"op_flags" for the state op.
If "o" is null, the state op is returned. Otherwise the state op is combined with "o"
into a "lineseq" list op, which is returned. "o" is consumed by this function and
becomes part of the returned op tree.
OP * newSTATEOP(I32 flags, char *label, OP *o)
"newSUB"
Construct a Perl subroutine without attributes, and also performing some surrounding
jobs, returning a pointer to the constructed subroutine.
This is the same as ""newATTRSUB_x"" in perlintern with its "o_is_gv" parameter set to
FALSE, and its "attrs" parameter to NULL. This means that if "o" is null, the new sub
will be anonymous; otherwise the name will be derived from "o" in the way described
(as with all other details) in ""newATTRSUB_x"" in perlintern.
CV * newSUB(I32 floor, OP *o, OP *proto, OP *block)
"newSVOP"
Constructs, checks, and returns an op of any type that involves an embedded SV.
"type" is the opcode. "flags" gives the eight bits of "op_flags". "sv" gives the SV
to embed in the op; this function takes ownership of one reference to it.
OP * newSVOP(I32 type, I32 flags, SV *sv)
"newSVREF"
Constructs, checks, and returns a scalar reference op.
OP * newSVREF(OP *o)
"newTRYCATCHOP"
NOTE: "newTRYCATCHOP" is experimental and may change or be removed without notice.
Constructs and returns a conditional execution statement that implements the
"try"/"catch" semantics. First the op tree in "tryblock" is executed, inside a
context that traps exceptions. If an exception occurs then the optree in "catchblock"
is executed, with the trapped exception set into the lexical variable given by
"catchvar" (which must be an op of type "OP_PADSV"). All the optrees are consumed by
this function and become part of the returned op tree.
The "flags" argument is currently ignored.
OP * newTRYCATCHOP(I32 flags, OP *tryblock, OP *catchvar,
OP *catchblock)
"newUNOP"
Constructs, checks, and returns an op of any unary type. "type" is the opcode.
"flags" gives the eight bits of "op_flags", except that "OPf_KIDS" will be set
automatically if required, and, shifted up eight bits, the eight bits of "op_private",
except that the bit with value 1 is automatically set. "first" supplies an optional
op to be the direct child of the unary op; it is consumed by this function and become
part of the constructed op tree.
OP * newUNOP(I32 type, I32 flags, OP *first)
"newUNOP_AUX"
Similar to "newUNOP", but creates an "UNOP_AUX" struct instead, with "op_aux"
initialised to "aux"
OP * newUNOP_AUX(I32 type, I32 flags, OP *first,
UNOP_AUX_item *aux)
"newWHENOP"
Constructs, checks, and returns an op tree expressing a "when" block. "cond" supplies
the test expression, and "block" supplies the block that will be executed if the test
evaluates to true; they are consumed by this function and become part of the
constructed op tree. "cond" will be interpreted DWIMically, often as a comparison
against $_, and may be null to generate a "default" block.
OP * newWHENOP(OP *cond, OP *block)
"newWHILEOP"
Constructs, checks, and returns an op tree expressing a "while" loop. This is a
heavyweight loop, with structure that allows exiting the loop by "last" and suchlike.
"loop" is an optional preconstructed "enterloop" op to use in the loop; if it is null
then a suitable op will be constructed automatically. "expr" supplies the loop's
controlling expression. "block" supplies the main body of the loop, and "cont"
optionally supplies a "continue" block that operates as a second half of the body.
All of these optree inputs are consumed by this function and become part of the
constructed op tree.
"flags" gives the eight bits of "op_flags" for the "leaveloop" op and, shifted up
eight bits, the eight bits of "op_private" for the "leaveloop" op, except that (in
both cases) some bits will be set automatically. "debuggable" is currently unused and
should always be 1. "has_my" can be supplied as true to force the loop body to be
enclosed in its own scope.
OP * newWHILEOP(I32 flags, I32 debuggable, LOOP *loop, OP *expr,
OP *block, OP *cont, I32 has_my)
"newXS"
Used by "xsubpp" to hook up XSUBs as Perl subs. "filename" needs to be static
storage, as it is used directly as CvFILE(), without a copy being made.
"OA_BASEOP"
"OA_BINOP"
"OA_COP"
"OA_LISTOP"
"OA_LOGOP"
"OA_LOOP"
"OA_PADOP"
"OA_PMOP"
"OA_PVOP_OR_SVOP"
"OA_SVOP"
"OA_UNOP"
Described in perlguts.
"OP"
Described in perlguts.
"op_append_elem"
Append an item to the list of ops contained directly within a list-type op, returning
the lengthened list. "first" is the list-type op, and "last" is the op to append to
the list. "optype" specifies the intended opcode for the list. If "first" is not
already a list of the right type, it will be upgraded into one. If either "first" or
"last" is null, the other is returned unchanged.
OP * op_append_elem(I32 optype, OP *first, OP *last)
"op_append_list"
Concatenate the lists of ops contained directly within two list-type ops, returning
the combined list. "first" and "last" are the list-type ops to concatenate. "optype"
specifies the intended opcode for the list. If either "first" or "last" is not
already a list of the right type, it will be upgraded into one. If either "first" or
"last" is null, the other is returned unchanged.
OP * op_append_list(I32 optype, OP *first, OP *last)
"OP_CLASS"
Return the class of the provided OP: that is, which of the *OP structures it uses.
For core ops this currently gets the information out of "PL_opargs", which does not
always accurately reflect the type used; in v5.26 onwards, see also the function
"op_class" which can do a better job of determining the used type.
For custom ops the type is returned from the registration, and it is up to the
registree to ensure it is accurate. The value returned will be one of the "OA_"*
constants from op.h.
U32 OP_CLASS(OP *o)
"op_contextualize"
Applies a syntactic context to an op tree representing an expression. "o" is the op
tree, and "context" must be "G_SCALAR", "G_LIST", or "G_VOID" to specify the context
to apply. The modified op tree is returned.
OP * op_contextualize(OP *o, I32 context)
"op_convert_list"
Converts "o" into a list op if it is not one already, and then converts it into the
specified "type", calling its check function, allocating a target if it needs one, and
folding constants.
A list-type op is usually constructed one kid at a time via "newLISTOP",
"op_prepend_elem" and "op_append_elem". Then finally it is passed to
"op_convert_list" to make it the right type.
OP * op_convert_list(I32 optype, I32 flags, OP *o)
"OP_DESC"
Return a short description of the provided OP.
const char * OP_DESC(OP *o)
"op_force_list"
Promotes o and any siblings to be an "OP_LIST" if it is not already. If a new
"OP_LIST" op was created, its first child will be "OP_PUSHMARK". The returned node
itself will be nulled, leaving only its children.
This is often what you want to do before putting the optree into list context; as
o = op_contextualize(op_force_list(o), G_LIST);
OP * op_force_list(OP *o)
"op_free"
Free an op and its children. Only use this when an op is no longer linked to from any
optree.
Remember that any op with "OPf_KIDS" set is expected to have a valid "op_first"
pointer. If you are attempting to free an op but preserve its child op, make sure to
clear that flag before calling op_free(). For example:
OP *kid = o->op_first; o->op_first = NULL;
o->op_flags &= ~OPf_KIDS;
op_free(o);
void op_free(OP *arg)
"OpHAS_SIBLING"
Returns true if "o" has a sibling
bool OpHAS_SIBLING(OP *o)
"OpLASTSIB_set"
Marks "o" as having no further siblings and marks o as having the specified parent.
See also "OpMORESIB_set" and "OpMAYBESIB_set". For a higher-level interface, see
"op_sibling_splice".
void OpLASTSIB_set(OP *o, OP *parent)
"op_linklist"
This function is the implementation of the "LINKLIST" macro. It should not be called
directly.
OP * op_linklist(OP *o)
"op_lvalue"
NOTE: "op_lvalue" is experimental and may change or be removed without notice.
Propagate lvalue ("modifiable") context to an op and its children. "type" represents
the context type, roughly based on the type of op that would do the modifying,
although local() is represented by "OP_NULL", because it has no op type of its own (it
is signalled by a flag on the lvalue op).
This function detects things that can't be modified, such as "$x+1", and generates
errors for them. For example, "$x+1 = 2" would cause it to be called with an op of
type "OP_ADD" and a "type" argument of "OP_SASSIGN".
It also flags things that need to behave specially in an lvalue context, such as "$$x
= 5" which might have to vivify a reference in $x.
OP * op_lvalue(OP *o, I32 type)
"OpMAYBESIB_set"
Conditionally does "OpMORESIB_set" or "OpLASTSIB_set" depending on whether "sib" is
non-null. For a higher-level interface, see "op_sibling_splice".
void OpMAYBESIB_set(OP *o, OP *sib, OP *parent)
"OpMORESIB_set"
Sets the sibling of "o" to the non-zero value "sib". See also "OpLASTSIB_set" and
"OpMAYBESIB_set". For a higher-level interface, see "op_sibling_splice".
void OpMORESIB_set(OP *o, OP *sib)
"OP_NAME"
Return the name of the provided OP. For core ops this looks up the name from the
op_type; for custom ops from the op_ppaddr.
const char * OP_NAME(OP *o)
"op_null"
Neutralizes an op when it is no longer needed, but is still linked to from other ops.
void op_null(OP *o)
"op_parent"
Returns the parent OP of "o", if it has a parent. Returns "NULL" otherwise.
OP * op_parent(OP *o)
"op_prepend_elem"
Prepend an item to the list of ops contained directly within a list-type op, returning
the lengthened list. "first" is the op to prepend to the list, and "last" is the
list-type op. "optype" specifies the intended opcode for the list. If "last" is not
already a list of the right type, it will be upgraded into one. If either "first" or
"last" is null, the other is returned unchanged.
OP * op_prepend_elem(I32 optype, OP *first, OP *last)
"op_scope"
NOTE: "op_scope" is experimental and may change or be removed without notice.
Wraps up an op tree with some additional ops so that at runtime a dynamic scope will
be created. The original ops run in the new dynamic scope, and then, provided that
they exit normally, the scope will be unwound. The additional ops used to create and
unwind the dynamic scope will normally be an "enter"/"leave" pair, but a "scope" op
may be used instead if the ops are simple enough to not need the full dynamic scope
structure.
OP * op_scope(OP *o)
"OpSIBLING"
Returns the sibling of "o", or "NULL" if there is no sibling
OP* OpSIBLING(OP *o)
"op_sibling_splice"
A general function for editing the structure of an existing chain of op_sibling nodes.
By analogy with the perl-level splice() function, allows you to delete zero or more
sequential nodes, replacing them with zero or more different nodes. Performs the
necessary op_first/op_last housekeeping on the parent node and op_sibling manipulation
on the children. The last deleted node will be marked as the last node by updating
the op_sibling/op_sibparent or op_moresib field as appropriate.
Note that op_next is not manipulated, and nodes are not freed; that is the
responsibility of the caller. It also won't create a new list op for an empty list
etc; use higher-level functions like op_append_elem() for that.
"parent" is the parent node of the sibling chain. It may passed as "NULL" if the
splicing doesn't affect the first or last op in the chain.
"start" is the node preceding the first node to be spliced. Node(s) following it will
be deleted, and ops will be inserted after it. If it is "NULL", the first node
onwards is deleted, and nodes are inserted at the beginning.
"del_count" is the number of nodes to delete. If zero, no nodes are deleted. If -1
or greater than or equal to the number of remaining kids, all remaining kids are
deleted.
"insert" is the first of a chain of nodes to be inserted in place of the nodes. If
"NULL", no nodes are inserted.
The head of the chain of deleted ops is returned, or "NULL" if no ops were deleted.
For example:
action before after returns
------ ----- ----- -------
P P
splice(P, A, 2, X-Y-Z) | | B-C
A-B-C-D A-X-Y-Z-D
P P
splice(P, NULL, 1, X-Y) | | A
A-B-C-D X-Y-B-C-D
P P
splice(P, NULL, 3, NULL) | | A-B-C
A-B-C-D D
P P
splice(P, B, 0, X-Y) | | NULL
A-B-C-D A-B-X-Y-C-D
For lower-level direct manipulation of "op_sibparent" and "op_moresib", see
"OpMORESIB_set", "OpLASTSIB_set", "OpMAYBESIB_set".
OP * op_sibling_splice(OP *parent, OP *start, int del_count,
OP *insert)
"optimize_optree"
This function applies some optimisations to the optree in top-down order. It is
called before the peephole optimizer, which processes ops in execution order. Note
that finalize_optree() also does a top-down scan, but is called *after* the peephole
optimizer.
void optimize_optree(OP *o)
"OP_TYPE_IS"
Returns true if the given OP is not a "NULL" pointer and if it is of the given type.
The negation of this macro, "OP_TYPE_ISNT" is also available as well as
"OP_TYPE_IS_NN" and "OP_TYPE_ISNT_NN" which elide the NULL pointer check.
bool OP_TYPE_IS(OP *o, Optype type)
"OP_TYPE_IS_OR_WAS"
Returns true if the given OP is not a NULL pointer and if it is of the given type or
used to be before being replaced by an OP of type OP_NULL.
The negation of this macro, "OP_TYPE_ISNT_AND_WASNT" is also available as well as
"OP_TYPE_IS_OR_WAS_NN" and "OP_TYPE_ISNT_AND_WASNT_NN" which elide the "NULL" pointer
check.
bool OP_TYPE_IS_OR_WAS(OP *o, Optype type)
"op_wrap_finally"
NOTE: "op_wrap_finally" is experimental and may change or be removed without notice.
Wraps the given "block" optree fragment in its own scoped block, arranging for the
"finally" optree fragment to be invoked when leaving that block for any reason. Both
optree fragments are consumed and the combined result is returned.
OP * op_wrap_finally(OP *block, OP *finally)
"peep_t"
Described in perlguts.
"Perl_cpeep_t"
Described in perlguts.
"PL_opfreehook"
When non-"NULL", the function pointed by this variable will be called each time an OP
is freed with the corresponding OP as the argument. This allows extensions to free
any extra attribute they have locally attached to an OP. It is also assured to first
fire for the parent OP and then for its kids.
When you replace this variable, it is considered a good practice to store the possibly
previously installed hook and that you recall it inside your own.
On threaded perls, each thread has an independent copy of this variable; each
initialized at creation time with the current value of the creating thread's copy.
Perl_ophook_t PL_opfreehook
"PL_peepp"
Pointer to the per-subroutine peephole optimiser. This is a function that gets called
at the end of compilation of a Perl subroutine (or equivalently independent piece of
Perl code) to perform fixups of some ops and to perform small-scale optimisations.
The function is called once for each subroutine that is compiled, and is passed, as
sole parameter, a pointer to the op that is the entry point to the subroutine. It
modifies the op tree in place.
The peephole optimiser should never be completely replaced. Rather, add code to it by
wrapping the existing optimiser. The basic way to do this can be seen in "Compile
pass 3: peephole optimization" in perlguts. If the new code wishes to operate on ops
throughout the subroutine's structure, rather than just at the top level, it is likely
to be more convenient to wrap the "PL_rpeepp" hook.
On threaded perls, each thread has an independent copy of this variable; each
initialized at creation time with the current value of the creating thread's copy.
peep_t PL_peepp
"PL_rpeepp"
Pointer to the recursive peephole optimiser. This is a function that gets called at
the end of compilation of a Perl subroutine (or equivalently independent piece of Perl
code) to perform fixups of some ops and to perform small-scale optimisations. The
function is called once for each chain of ops linked through their "op_next" fields;
it is recursively called to handle each side chain. It is passed, as sole parameter,
a pointer to the op that is at the head of the chain. It modifies the op tree in
place.
The peephole optimiser should never be completely replaced. Rather, add code to it by
wrapping the existing optimiser. The basic way to do this can be seen in "Compile
pass 3: peephole optimization" in perlguts. If the new code wishes to operate only on
ops at a subroutine's top level, rather than throughout the structure, it is likely to
be more convenient to wrap the "PL_peepp" hook.
On threaded perls, each thread has an independent copy of this variable; each
initialized at creation time with the current value of the creating thread's copy.
peep_t PL_rpeepp
"PMOP"
Described in perlguts.
"rv2cv_op_cv"
Examines an op, which is expected to identify a subroutine at runtime, and attempts to
determine at compile time which subroutine it identifies. This is normally used
during Perl compilation to determine whether a prototype can be applied to a function
call. "cvop" is the op being considered, normally an "rv2cv" op. A pointer to the
identified subroutine is returned, if it could be determined statically, and a null
pointer is returned if it was not possible to determine statically.
Currently, the subroutine can be identified statically if the RV that the "rv2cv" is
to operate on is provided by a suitable "gv" or "const" op. A "gv" op is suitable if
the GV's CV slot is populated. A "const" op is suitable if the constant value must be
an RV pointing to a CV. Details of this process may change in future versions of
Perl. If the "rv2cv" op has the "OPpENTERSUB_AMPER" flag set then no attempt is made
to identify the subroutine statically: this flag is used to suppress compile-time
magic on a subroutine call, forcing it to use default runtime behaviour.
If "flags" has the bit "RV2CVOPCV_MARK_EARLY" set, then the handling of a GV reference
is modified. If a GV was examined and its CV slot was found to be empty, then the
"gv" op has the "OPpEARLY_CV" flag set. If the op is not optimised away, and the CV
slot is later populated with a subroutine having a prototype, that flag eventually
triggers the warning "called too early to check prototype".
If "flags" has the bit "RV2CVOPCV_RETURN_NAME_GV" set, then instead of returning a
pointer to the subroutine it returns a pointer to the GV giving the most appropriate
name for the subroutine in this context. Normally this is just the "CvGV" of the
subroutine, but for an anonymous ("CvANON") subroutine that is referenced through a GV
it will be the referencing GV. The resulting "GV*" is cast to "CV*" to be returned.
A null pointer is returned as usual if there is no statically-determinable subroutine.
CV * rv2cv_op_cv(OP *cvop, U32 flags)
"UNOP"
Described in perlguts.
"XOP"
Described in perlguts.
Pack and Unpack
"packlist"
The engine implementing pack() Perl function.
void packlist(SV *cat, const char *pat, const char *patend,
SV **beglist, SV **endlist)
"unpackstring"
The engine implementing the unpack() Perl function.
Using the template "pat..patend", this function unpacks the string "s..strend" into a
number of mortal SVs, which it pushes onto the perl argument (@_) stack (so you will
need to issue a "PUTBACK" before and "SPAGAIN" after the call to this function). It
returns the number of pushed elements.
The "strend" and "patend" pointers should point to the byte following the last
character of each string.
Although this function returns its values on the perl argument stack, it doesn't take
any parameters from that stack (and thus in particular there's no need to do a
"PUSHMARK" before calling it, unlike "call_pv" for example).
SSize_t unpackstring(const char *pat, const char *patend,
const char *s, const char *strend,
U32 flags)
Pad Data Structures
"CvPADLIST"
NOTE: "CvPADLIST" is experimental and may change or be removed without notice.
CV's can have CvPADLIST(cv) set to point to a PADLIST. This is the CV's scratchpad,
which stores lexical variables and opcode temporary and per-thread values.
For these purposes "formats" are a kind-of CV; eval""s are too (except they're not
callable at will and are always thrown away after the eval"" is done executing).
Require'd files are simply evals without any outer lexical scope.
XSUBs do not have a "CvPADLIST". "dXSTARG" fetches values from "PL_curpad", but that
is really the callers pad (a slot of which is allocated by every entersub). Do not get
or set "CvPADLIST" if a CV is an XSUB (as determined by CvISXSUB()), "CvPADLIST" slot
is reused for a different internal purpose in XSUBs.
The PADLIST has a C array where pads are stored.
The 0th entry of the PADLIST is a PADNAMELIST which represents the "names" or rather
the "static type information" for lexicals. The individual elements of a PADNAMELIST
are PADNAMEs. Future refactorings might stop the PADNAMELIST from being stored in the
PADLIST's array, so don't rely on it. See "PadlistNAMES".
The CvDEPTH'th entry of a PADLIST is a PAD (an AV) which is the stack frame at that
depth of recursion into the CV. The 0th slot of a frame AV is an AV which is @_.
Other entries are storage for variables and op targets.
Iterating over the PADNAMELIST iterates over all possible pad items. Pad slots for
targets ("SVs_PADTMP") and GVs end up having &PL_padname_undef "names", while slots
for constants have &PL_padname_const "names" (see "pad_alloc"). That
&PL_padname_undef and &PL_padname_const are used is an implementation detail subject
to change. To test for them, use "!PadnamePV(name)" and
"PadnamePV(name) && !PadnameLEN(name)", respectively.
Only "my"/"our" variable slots get valid names. The rest are op targets/GVs/constants
which are statically allocated or resolved at compile time. These don't have names by
which they can be looked up from Perl code at run time through eval"" the way
"my"/"our" variables can be. Since they can't be looked up by "name" but only by
their index allocated at compile time (which is usually in "PL_op->op_targ"), wasting
a name SV for them doesn't make sense.
The pad names in the PADNAMELIST have their PV holding the name of the variable. The
"COP_SEQ_RANGE_LOW" and "_HIGH" fields form a range (low+1..high inclusive) of cop_seq
numbers for which the name is valid. During compilation, these fields may hold the
special value PERL_PADSEQ_INTRO to indicate various stages:
COP_SEQ_RANGE_LOW _HIGH
----------------- -----
PERL_PADSEQ_INTRO 0 variable not yet introduced:
{ my ($x
valid-seq# PERL_PADSEQ_INTRO variable in scope:
{ my ($x);
valid-seq# valid-seq# compilation of scope complete:
{ my ($x); .... }
When a lexical var hasn't yet been introduced, it already exists from the perspective
of duplicate declarations, but not for variable lookups, e.g.
my ($x, $x); # '"my" variable $x masks earlier declaration'
my $x = $x; # equal to my $x = $::x;
For typed lexicals "PadnameTYPE" points at the type stash. For "our" lexicals,
"PadnameOURSTASH" points at the stash of the associated global (so that duplicate
"our" declarations in the same package can be detected). "PadnameGEN" is sometimes
used to store the generation number during compilation.
If "PadnameOUTER" is set on the pad name, then that slot in the frame AV is a
REFCNT'ed reference to a lexical from "outside". Such entries are sometimes referred
to as 'fake'. In this case, the name does not use 'low' and 'high' to store a cop_seq
range, since it is in scope throughout. Instead 'high' stores some flags containing
info about the real lexical (is it declared in an anon, and is it capable of being
instantiated multiple times?), and for fake ANONs, 'low' contains the index within the
parent's pad where the lexical's value is stored, to make cloning quicker.
If the 'name' is "&" the corresponding entry in the PAD is a CV representing a
possible closure.
Note that formats are treated as anon subs, and are cloned each time write is called
(if necessary).
The flag "SVs_PADSTALE" is cleared on lexicals each time the my() is executed, and set
on scope exit. This allows the "Variable $x is not available" warning to be generated
in evals, such as
{ my $x = 1; sub f { eval '$x'} } f();
For state vars, "SVs_PADSTALE" is overloaded to mean 'not yet initialised', but this
internal state is stored in a separate pad entry.
PADLIST * CvPADLIST(CV *cv)
"pad_add_name_pvs"
Exactly like "pad_add_name_pvn", but takes a literal string instead of a string/length
pair.
PADOFFSET pad_add_name_pvs("name", U32 flags, HV *typestash,
HV *ourstash)
"PadARRAY"
NOTE: "PadARRAY" is experimental and may change or be removed without notice.
The C array of pad entries.
SV ** PadARRAY(PAD * pad)
"pad_findmy_pvs"
Exactly like "pad_findmy_pvn", but takes a literal string instead of a string/length
pair.
PADOFFSET pad_findmy_pvs("name", U32 flags)
"PadlistARRAY"
NOTE: "PadlistARRAY" is experimental and may change or be removed without notice.
The C array of a padlist, containing the pads. Only subscript it with numbers >= 1,
as the 0th entry is not guaranteed to remain usable.
PAD ** PadlistARRAY(PADLIST * padlist)
"PadlistMAX"
NOTE: "PadlistMAX" is experimental and may change or be removed without notice.
The index of the last allocated space in the padlist. Note that the last pad may be
in an earlier slot. Any entries following it will be "NULL" in that case.
SSize_t PadlistMAX(PADLIST * padlist)
"PadlistNAMES"
NOTE: "PadlistNAMES" is experimental and may change or be removed without notice.
The names associated with pad entries.
PADNAMELIST * PadlistNAMES(PADLIST * padlist)
"PadlistNAMESARRAY"
NOTE: "PadlistNAMESARRAY" is experimental and may change or be removed without notice.
The C array of pad names.
PADNAME ** PadlistNAMESARRAY(PADLIST * padlist)
"PadlistNAMESMAX"
NOTE: "PadlistNAMESMAX" is experimental and may change or be removed without notice.
The index of the last pad name.
SSize_t PadlistNAMESMAX(PADLIST * padlist)
"PadlistREFCNT"
NOTE: "PadlistREFCNT" is experimental and may change or be removed without notice.
The reference count of the padlist. Currently this is always 1.
U32 PadlistREFCNT(PADLIST * padlist)
"PadMAX"
NOTE: "PadMAX" is experimental and may change or be removed without notice.
The index of the last pad entry.
SSize_t PadMAX(PAD * pad)
"PadnameLEN"
NOTE: "PadnameLEN" is experimental and may change or be removed without notice.
The length of the name.
STRLEN PadnameLEN(PADNAME * pn)
"PadnamelistARRAY"
NOTE: "PadnamelistARRAY" is experimental and may change or be removed without notice.
The C array of pad names.
PADNAME ** PadnamelistARRAY(PADNAMELIST * pnl)
"PadnamelistMAX"
NOTE: "PadnamelistMAX" is experimental and may change or be removed without notice.
The index of the last pad name.
SSize_t PadnamelistMAX(PADNAMELIST * pnl)
"PadnamelistREFCNT"
NOTE: "PadnamelistREFCNT" is experimental and may change or be removed without notice.
The reference count of the pad name list.
SSize_t PadnamelistREFCNT(PADNAMELIST * pnl)
"PadnamelistREFCNT_dec"
NOTE: "PadnamelistREFCNT_dec" is experimental and may change or be removed without
notice.
Lowers the reference count of the pad name list.
void PadnamelistREFCNT_dec(PADNAMELIST * pnl)
"PadnamePV"
NOTE: "PadnamePV" is experimental and may change or be removed without notice.
The name stored in the pad name struct. This returns "NULL" for a target slot.
char * PadnamePV(PADNAME * pn)
"PadnameREFCNT"
NOTE: "PadnameREFCNT" is experimental and may change or be removed without notice.
The reference count of the pad name.
SSize_t PadnameREFCNT(PADNAME * pn)
"PadnameREFCNT_dec"
NOTE: "PadnameREFCNT_dec" is experimental and may change or be removed without notice.
Lowers the reference count of the pad name.
void PadnameREFCNT_dec(PADNAME * pn)
"PadnameREFCNT_inc"
NOTE: "PadnameREFCNT_inc" is experimental and may change or be removed without notice.
Increases the reference count of the pad name. Returns the pad name itself.
PADNAME * PadnameREFCNT_inc(PADNAME * pn)
"PadnameSV"
NOTE: "PadnameSV" is experimental and may change or be removed without notice.
Returns the pad name as a mortal SV.
SV * PadnameSV(PADNAME * pn)
"PadnameUTF8"
NOTE: "PadnameUTF8" is experimental and may change or be removed without notice.
Whether PadnamePV is in UTF-8. Currently, this is always true.
bool PadnameUTF8(PADNAME * pn)
"pad_new"
Create a new padlist, updating the global variables for the currently-compiling
padlist to point to the new padlist. The following flags can be OR'ed together:
padnew_CLONE this pad is for a cloned CV
padnew_SAVE save old globals on the save stack
padnew_SAVESUB also save extra stuff for start of sub
PADLIST * pad_new(int flags)
"PL_comppad"
NOTE: "PL_comppad" is experimental and may change or be removed without notice.
During compilation, this points to the array containing the values part of the pad for
the currently-compiling code. (At runtime a CV may have many such value arrays; at
compile time just one is constructed.) At runtime, this points to the array
containing the currently-relevant values for the pad for the currently-executing code.
"PL_comppad_name"
NOTE: "PL_comppad_name" is experimental and may change or be removed without notice.
During compilation, this points to the array containing the names part of the pad for
the currently-compiling code.
"PL_curpad"
NOTE: "PL_curpad" is experimental and may change or be removed without notice.
Points directly to the body of the "PL_comppad" array. (I.e., this is
PadARRAY(PL_comppad).)
"SVs_PADMY"
"DEPRECATED!" It is planned to remove "SVs_PADMY" from a future release of Perl. Do
not use it for new code; remove it from existing code.
Described in perlguts.
"SVs_PADTMP"
Described in perlguts.
Password and Group access
"GRPASSWD"
This symbol, if defined, indicates to the C program that "struct group" in grp.h
contains "gr_passwd".
"HAS_ENDGRENT"
This symbol, if defined, indicates that the getgrent routine is available for
finalizing sequential access of the group database.
"HAS_ENDGRENT_R"
This symbol, if defined, indicates that the "endgrent_r" routine is available to
endgrent re-entrantly.
"HAS_ENDPWENT"
This symbol, if defined, indicates that the "endpwent" routine is available for
finalizing sequential access of the passwd database.
"HAS_ENDPWENT_R"
This symbol, if defined, indicates that the "endpwent_r" routine is available to
endpwent re-entrantly.
"HAS_GETGRENT"
This symbol, if defined, indicates that the "getgrent" routine is available for
sequential access of the group database.
"HAS_GETGRENT_R"
This symbol, if defined, indicates that the "getgrent_r" routine is available to
getgrent re-entrantly.
"HAS_GETPWENT"
This symbol, if defined, indicates that the "getpwent" routine is available for
sequential access of the passwd database. If this is not available, the older getpw()
function may be available.
"HAS_GETPWENT_R"
This symbol, if defined, indicates that the "getpwent_r" routine is available to
getpwent re-entrantly.
"HAS_SETGRENT"
This symbol, if defined, indicates that the "setgrent" routine is available for
initializing sequential access of the group database.
"HAS_SETGRENT_R"
This symbol, if defined, indicates that the "setgrent_r" routine is available to
setgrent re-entrantly.
"HAS_SETPWENT"
This symbol, if defined, indicates that the "setpwent" routine is available for
initializing sequential access of the passwd database.
"HAS_SETPWENT_R"
This symbol, if defined, indicates that the "setpwent_r" routine is available to
setpwent re-entrantly.
"PWAGE"
This symbol, if defined, indicates to the C program that "struct passwd" contains
"pw_age".
"PWCHANGE"
This symbol, if defined, indicates to the C program that "struct passwd" contains
"pw_change".
"PWCLASS"
This symbol, if defined, indicates to the C program that "struct passwd" contains
"pw_class".
"PWCOMMENT"
This symbol, if defined, indicates to the C program that "struct passwd" contains
"pw_comment".
"PWEXPIRE"
This symbol, if defined, indicates to the C program that "struct passwd" contains
"pw_expire".
"PWGECOS"
This symbol, if defined, indicates to the C program that "struct passwd" contains
"pw_gecos".
"PWPASSWD"
This symbol, if defined, indicates to the C program that "struct passwd" contains
"pw_passwd".
"PWQUOTA"
This symbol, if defined, indicates to the C program that "struct passwd" contains
"pw_quota".
Paths to system commands
"CSH"
This symbol, if defined, contains the full pathname of csh.
"LOC_SED"
This symbol holds the complete pathname to the sed program.
"SH_PATH"
This symbol contains the full pathname to the shell used on this on this system to
execute Bourne shell scripts. Usually, this will be /bin/sh, though it's possible
that some systems will have /bin/ksh, /bin/pdksh, /bin/ash, /bin/bash, or even
something such as D:/bin/sh.exe.
Prototype information
"CRYPT_R_PROTO"
This symbol encodes the prototype of "crypt_r". It is zero if "d_crypt_r" is undef,
and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_crypt_r" is defined.
"CTERMID_R_PROTO"
This symbol encodes the prototype of "ctermid_r". It is zero if "d_ctermid_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_ctermid_r" is
defined.
"DRAND48_R_PROTO"
This symbol encodes the prototype of "drand48_r". It is zero if "d_drand48_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_drand48_r" is
defined.
"ENDGRENT_R_PROTO"
This symbol encodes the prototype of "endgrent_r". It is zero if "d_endgrent_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_endgrent_r" is
defined.
"ENDHOSTENT_R_PROTO"
This symbol encodes the prototype of "endhostent_r". It is zero if "d_endhostent_r"
is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if
"d_endhostent_r" is defined.
"ENDNETENT_R_PROTO"
This symbol encodes the prototype of "endnetent_r". It is zero if "d_endnetent_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_endnetent_r" is
defined.
"ENDPROTOENT_R_PROTO"
This symbol encodes the prototype of "endprotoent_r". It is zero if "d_endprotoent_r"
is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if
"d_endprotoent_r" is defined.
"ENDPWENT_R_PROTO"
This symbol encodes the prototype of "endpwent_r". It is zero if "d_endpwent_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_endpwent_r" is
defined.
"ENDSERVENT_R_PROTO"
This symbol encodes the prototype of "endservent_r". It is zero if "d_endservent_r"
is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if
"d_endservent_r" is defined.
"GDBMNDBM_H_USES_PROTOTYPES"
This symbol, if defined, indicates that gdbm/ndbm.h uses real "ANSI" C prototypes
instead of K&R style function declarations without any parameter information. While
"ANSI" C prototypes are supported in C++, K&R style function declarations will yield
errors.
"GDBM_NDBM_H_USES_PROTOTYPES"
This symbol, if defined, indicates that <gdbm-ndbm.h> uses real "ANSI" C prototypes
instead of K&R style function declarations without any parameter information. While
"ANSI" C prototypes are supported in C++, K&R style function declarations will yield
errors.
"GETGRENT_R_PROTO"
This symbol encodes the prototype of "getgrent_r". It is zero if "d_getgrent_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_getgrent_r" is
defined.
"GETGRGID_R_PROTO"
This symbol encodes the prototype of "getgrgid_r". It is zero if "d_getgrgid_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_getgrgid_r" is
defined.
"GETGRNAM_R_PROTO"
This symbol encodes the prototype of "getgrnam_r". It is zero if "d_getgrnam_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_getgrnam_r" is
defined.
"GETHOSTBYADDR_R_PROTO"
This symbol encodes the prototype of "gethostbyaddr_r". It is zero if
"d_gethostbyaddr_r" is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of
reentr.h if "d_gethostbyaddr_r" is defined.
"GETHOSTBYNAME_R_PROTO"
This symbol encodes the prototype of "gethostbyname_r". It is zero if
"d_gethostbyname_r" is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of
reentr.h if "d_gethostbyname_r" is defined.
"GETHOSTENT_R_PROTO"
This symbol encodes the prototype of "gethostent_r". It is zero if "d_gethostent_r"
is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if
"d_gethostent_r" is defined.
"GETLOGIN_R_PROTO"
This symbol encodes the prototype of "getlogin_r". It is zero if "d_getlogin_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_getlogin_r" is
defined.
"GETNETBYADDR_R_PROTO"
This symbol encodes the prototype of "getnetbyaddr_r". It is zero if
"d_getnetbyaddr_r" is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h
if "d_getnetbyaddr_r" is defined.
"GETNETBYNAME_R_PROTO"
This symbol encodes the prototype of "getnetbyname_r". It is zero if
"d_getnetbyname_r" is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h
if "d_getnetbyname_r" is defined.
"GETNETENT_R_PROTO"
This symbol encodes the prototype of "getnetent_r". It is zero if "d_getnetent_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_getnetent_r" is
defined.
"GETPROTOBYNAME_R_PROTO"
This symbol encodes the prototype of "getprotobyname_r". It is zero if
"d_getprotobyname_r" is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of
reentr.h if "d_getprotobyname_r" is defined.
"GETPROTOBYNUMBER_R_PROTO"
This symbol encodes the prototype of "getprotobynumber_r". It is zero if
"d_getprotobynumber_r" is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of
reentr.h if "d_getprotobynumber_r" is defined.
"GETPROTOENT_R_PROTO"
This symbol encodes the prototype of "getprotoent_r". It is zero if "d_getprotoent_r"
is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if
"d_getprotoent_r" is defined.
"GETPWENT_R_PROTO"
This symbol encodes the prototype of "getpwent_r". It is zero if "d_getpwent_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_getpwent_r" is
defined.
"GETPWNAM_R_PROTO"
This symbol encodes the prototype of "getpwnam_r". It is zero if "d_getpwnam_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_getpwnam_r" is
defined.
"GETPWUID_R_PROTO"
This symbol encodes the prototype of "getpwuid_r". It is zero if "d_getpwuid_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_getpwuid_r" is
defined.
"GETSERVBYNAME_R_PROTO"
This symbol encodes the prototype of "getservbyname_r". It is zero if
"d_getservbyname_r" is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of
reentr.h if "d_getservbyname_r" is defined.
"GETSERVBYPORT_R_PROTO"
This symbol encodes the prototype of "getservbyport_r". It is zero if
"d_getservbyport_r" is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of
reentr.h if "d_getservbyport_r" is defined.
"GETSERVENT_R_PROTO"
This symbol encodes the prototype of "getservent_r". It is zero if "d_getservent_r"
is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if
"d_getservent_r" is defined.
"GETSPNAM_R_PROTO"
This symbol encodes the prototype of "getspnam_r". It is zero if "d_getspnam_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_getspnam_r" is
defined.
"HAS_DBMINIT_PROTO"
This symbol, if defined, indicates that the system provides a prototype for the
dbminit() function. Otherwise, it is up to the program to supply one. A good guess
is
extern int dbminit(char *);
"HAS_DRAND48_PROTO"
This symbol, if defined, indicates that the system provides a prototype for the
drand48() function. Otherwise, it is up to the program to supply one. A good guess
is
extern double drand48(void);
"HAS_FLOCK_PROTO"
This symbol, if defined, indicates that the system provides a prototype for the
flock() function. Otherwise, it is up to the program to supply one. A good guess is
extern int flock(int, int);
"HAS_GETHOST_PROTOS"
This symbol, if defined, indicates that netdb.h includes prototypes for gethostent(),
gethostbyname(), and gethostbyaddr(). Otherwise, it is up to the program to guess
them. See netdbtype.U (part of metaconfig) for probing for various "Netdb_xxx_t"
types.
"HAS_GETNET_PROTOS"
This symbol, if defined, indicates that netdb.h includes prototypes for getnetent(),
getnetbyname(), and getnetbyaddr(). Otherwise, it is up to the program to guess them.
See netdbtype.U (part of metaconfig) for probing for various "Netdb_xxx_t" types.
"HAS_GETPROTO_PROTOS"
This symbol, if defined, indicates that netdb.h includes prototypes for getprotoent(),
getprotobyname(), and getprotobyaddr(). Otherwise, it is up to the program to guess
them. See netdbtype.U (part of metaconfig) for probing for various "Netdb_xxx_t"
types.
"HAS_GETSERV_PROTOS"
This symbol, if defined, indicates that netdb.h includes prototypes for getservent(),
getservbyname(), and getservbyaddr(). Otherwise, it is up to the program to guess
them. See netdbtype.U (part of metaconfig) for probing for various "Netdb_xxx_t"
types.
"HAS_MODFL_PROTO"
This symbol, if defined, indicates that the system provides a prototype for the
modfl() function. Otherwise, it is up to the program to supply one.
"HAS_SBRK_PROTO"
This symbol, if defined, indicates that the system provides a prototype for the sbrk()
function. Otherwise, it is up to the program to supply one. Good guesses are
extern void* sbrk(int);
extern void* sbrk(size_t);
"HAS_SETRESGID_PROTO"
This symbol, if defined, indicates that the system provides a prototype for the
setresgid() function. Otherwise, it is up to the program to supply one. Good guesses
are
extern int setresgid(uid_t ruid, uid_t euid, uid_t suid);
"HAS_SETRESUID_PROTO"
This symbol, if defined, indicates that the system provides a prototype for the
setresuid() function. Otherwise, it is up to the program to supply one. Good guesses
are
extern int setresuid(uid_t ruid, uid_t euid, uid_t suid);
"HAS_SHMAT_PROTOTYPE"
This symbol, if defined, indicates that the sys/shm.h includes a prototype for
shmat(). Otherwise, it is up to the program to guess one. "Shmat_t" "shmat(int,
Shmat_t, int)" is a good guess, but not always right so it should be emitted by the
program only when "HAS_SHMAT_PROTOTYPE" is not defined to avoid conflicting defs.
"HAS_SOCKATMARK_PROTO"
This symbol, if defined, indicates that the system provides a prototype for the
sockatmark() function. Otherwise, it is up to the program to supply one. A good
guess is
extern int sockatmark(int);
"HAS_SYSCALL_PROTO"
This symbol, if defined, indicates that the system provides a prototype for the
syscall() function. Otherwise, it is up to the program to supply one. Good guesses
are
extern int syscall(int, ...);
extern int syscall(long, ...);
"HAS_TELLDIR_PROTO"
This symbol, if defined, indicates that the system provides a prototype for the
telldir() function. Otherwise, it is up to the program to supply one. A good guess
is
extern long telldir(DIR*);
"NDBM_H_USES_PROTOTYPES"
This symbol, if defined, indicates that ndbm.h uses real "ANSI" C prototypes instead
of K&R style function declarations without any parameter information. While "ANSI" C
prototypes are supported in C++, K&R style function declarations will yield errors.
"RANDOM_R_PROTO"
This symbol encodes the prototype of "random_r". It is zero if "d_random_r" is undef,
and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_random_r" is defined.
"READDIR_R_PROTO"
This symbol encodes the prototype of "readdir_r". It is zero if "d_readdir_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_readdir_r" is
defined.
"SETGRENT_R_PROTO"
This symbol encodes the prototype of "setgrent_r". It is zero if "d_setgrent_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_setgrent_r" is
defined.
"SETHOSTENT_R_PROTO"
This symbol encodes the prototype of "sethostent_r". It is zero if "d_sethostent_r"
is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if
"d_sethostent_r" is defined.
"SETLOCALE_R_PROTO"
This symbol encodes the prototype of "setlocale_r". It is zero if "d_setlocale_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_setlocale_r" is
defined.
"SETNETENT_R_PROTO"
This symbol encodes the prototype of "setnetent_r". It is zero if "d_setnetent_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_setnetent_r" is
defined.
"SETPROTOENT_R_PROTO"
This symbol encodes the prototype of "setprotoent_r". It is zero if "d_setprotoent_r"
is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if
"d_setprotoent_r" is defined.
"SETPWENT_R_PROTO"
This symbol encodes the prototype of "setpwent_r". It is zero if "d_setpwent_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_setpwent_r" is
defined.
"SETSERVENT_R_PROTO"
This symbol encodes the prototype of "setservent_r". It is zero if "d_setservent_r"
is undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if
"d_setservent_r" is defined.
"SRANDOM_R_PROTO"
This symbol encodes the prototype of "srandom_r". It is zero if "d_srandom_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_srandom_r" is
defined.
"SRAND48_R_PROTO"
This symbol encodes the prototype of "srand48_r". It is zero if "d_srand48_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_srand48_r" is
defined.
"STRERROR_R_PROTO"
This symbol encodes the prototype of "strerror_r". It is zero if "d_strerror_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_strerror_r" is
defined.
"TMPNAM_R_PROTO"
This symbol encodes the prototype of "tmpnam_r". It is zero if "d_tmpnam_r" is undef,
and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_tmpnam_r" is defined.
"TTYNAME_R_PROTO"
This symbol encodes the prototype of "ttyname_r". It is zero if "d_ttyname_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_ttyname_r" is
defined.
Reference-counted stack manipulation
Functions for pushing and pulling items on the stack when the stack is reference counted.
They are intended as replacements for the old PUSHs, POPi, EXTEND etc pp macros within pp
functions.
"rpp_context"
NOTE: "rpp_context" is experimental and may change or be removed without notice.
Impose void, scalar or list context on the stack. First, pop "extra" items off the
stack, then when "gimme" is: "G_LIST": return as-is. "G_VOID": pop everything
back to "mark" "G_SCALAR": move the top stack item (or &PL_sv_undef if none) to
"mark+1" and free everything above it.
void rpp_context(SV **mark, U8 gimme, SSize_t extra)
"rpp_extend"
NOTE: "rpp_extend" is experimental and may change or be removed without notice.
Ensures that there is space on the stack to push "n" items, extending it if necessary.
void rpp_extend(SSize_t n)
"rpp_invoke_xs"
NOTE: "rpp_invoke_xs" is experimental and may change or be removed without notice.
Call the XS function associated with "cv". Wraps the call if necessary to handle XS
functions which are not aware of reference-counted stacks.
void rpp_invoke_xs(CV *cv)
"rpp_is_lone"
NOTE: "rpp_is_lone" is experimental and may change or be removed without notice.
Indicates whether the stacked SV "sv" (assumed to be not yet popped off the stack) is
only kept alive due to a single reference from the argument stack and/or and the temps
stack.
This can used for example to decide whether the copying of return values in rvalue
context can be skipped, or whether it shouldn't be assigned to in lvalue context.
bool rpp_is_lone(SV *sv)
"rpp_popfree_1_NN"
NOTE: "rpp_popfree_1_NN" is experimental and may change or be removed without notice.
A variant of rpp_popfree_1() which assumes that the pointer being popped off the stack
is non-NULL.
void rpp_popfree_1_NN()
"rpp_popfree_2_NN"
NOTE: "rpp_popfree_2_NN" is experimental and may change or be removed without notice.
A variant of rpp_popfree_2() which assumes that the two pointers being popped off the
stack are non-NULL.
void rpp_popfree_2_NN()
"rpp_popfree_to"
NOTE: "rpp_popfree_to" is experimental and may change or be removed without notice.
Pop and free all items on the argument stack above "sp". On return, "PL_stack_sp" will
be equal to "sp".
void rpp_popfree_to(SV **sp)
"rpp_popfree_to_NN"
NOTE: "rpp_popfree_to_NN" is experimental and may change or be removed without notice.
A variant of rpp_popfree_to() which assumes that all the pointers being popped off the
stack are non-NULL.
void rpp_popfree_to_NN(SV **sp)
"rpp_popfree_1"
NOTE: "rpp_popfree_1" is experimental and may change or be removed without notice.
Pop and free the top item on the argument stack and update "PL_stack_sp".
void rpp_popfree_1()
"rpp_popfree_2"
NOTE: "rpp_popfree_2" is experimental and may change or be removed without notice.
Pop and free the top two items on the argument stack and update "PL_stack_sp".
void rpp_popfree_2()
"rpp_pop_1_norc"
NOTE: "rpp_pop_1_norc" is experimental and may change or be removed without notice.
Pop and return the top item off the argument stack and update "PL_stack_sp". It's
similar to rpp_popfree_1(), except that it actually returns a value, and it doesn't
decrement the SV's reference count. On non-"PERL_RC_STACK" builds it actually
increments the SV's reference count.
This is useful in cases where the popped value is immediately embedded somewhere e.g.
via av_store(), allowing you skip decrementing and then immediately incrementing the
reference count again (and risk prematurely freeing the SV if it had a RC of 1). On
non-RC builds, the reference count bookkeeping still works too, which is why it should
be used rather than a simple "*PL_stack_sp--".
SV * rpp_pop_1_norc()
"rpp_push_1_norc"
NOTE: "rpp_push_1_norc" is experimental and may change or be removed without notice.
Push "sv" onto the stack without incrementing its reference count, and update
"PL_stack_sp". On non-PERL_RC_STACK builds, mortalise too.
This is most useful where an SV has just been created and already has a reference
count of 1, but has not yet been anchored anywhere.
void rpp_push_1_norc(SV *sv)
"rpp_push_1"
"rpp_push_IMM"
"rpp_push_2"
"rpp_xpush_1"
"rpp_xpush_IMM"
"rpp_xpush_2"
NOTE: all these forms are experimental and may change or be removed without notice.
Push one or two SVs onto the stack, incrementing their reference counts and updating
"PL_stack_sp". With the "x" variants, it extends the stack first. The "IMM" variants
assume that the single argument is an immortal such as <&PL_sv_undef> and, for
efficiency, will skip incrementing its reference count.
void rpp_push_1 (SV *sv)
void rpp_push_IMM (SV *sv)
void rpp_push_2 (SV *sv1, SV *sv2)
void rpp_xpush_1 (SV *sv)
void rpp_xpush_IMM(SV *sv)
void rpp_xpush_2 (SV *sv1, SV *sv2)
"rpp_replace_at"
NOTE: "rpp_replace_at" is experimental and may change or be removed without notice.
Replace the SV at address sp within the stack with "sv", while suitably adjusting
reference counts. Equivalent to "*sp = sv", except with proper reference count
handling.
void rpp_replace_at(SV **sp, SV *sv)
"rpp_replace_at_NN"
NOTE: "rpp_replace_at_NN" is experimental and may change or be removed without notice.
A variant of rpp_replace_at() which assumes that the SV pointer on the stack is non-
NULL.
void rpp_replace_at_NN(SV **sp, SV *sv)
"rpp_replace_at_norc"
NOTE: "rpp_replace_at_norc" is experimental and may change or be removed without
notice.
Replace the SV at address sp within the stack with "sv", while suitably adjusting the
reference count of the old SV. Equivalent to "*sp = sv", except with proper reference
count handling.
"sv"'s reference count doesn't get incremented. On non-"PERL_RC_STACK" builds, it gets
mortalised too.
This is most useful where an SV has just been created and already has a reference
count of 1, but has not yet been anchored anywhere.
void rpp_replace_at_norc(SV **sp, SV *sv)
"rpp_replace_at_norc_NN"
NOTE: "rpp_replace_at_norc_NN" is experimental and may change or be removed without
notice.
A variant of rpp_replace_at_norc() which assumes that the SV pointer on the stack is
non-NULL.
void rpp_replace_at_norc_NN(SV **sp, SV *sv)
"rpp_replace_1_1"
"rpp_replace_1_1_NN"
"rpp_replace_1_IMM_NN"
NOTE: all these forms are experimental and may change or be removed without notice.
Replace the current top stack item with "sv", while suitably adjusting reference
counts. Equivalent to rpp_popfree_1(); rpp_push_1(sv), but is more efficient and
handles both SVs being the same.
The "_NN" variant assumes that the pointer on the stack to the SV being freed is non-
NULL.
The "IMM_NN" variant is like the "_NN" variant, but in addition, assumes that the
single argument is an immortal such as <&PL_sv_undef> and, for efficiency, will skip
incrementing its reference count.
void rpp_replace_1_1(SV *sv)
"rpp_replace_2_1"
"rpp_replace_2_1_NN"
"rpp_replace_2_IMM_NN"
NOTE: all these forms are experimental and may change or be removed without notice.
Replace the current top to stacks item with "sv", while suitably adjusting reference
counts. Equivalent to rpp_popfree_2(); rpp_push_1(sv), but is more efficient and
handles SVs being the same.
The "_NN" variant assumes that the pointers on the stack to the SVs being freed are
non-NULL.
The "IMM_NN" variant is like the "_NN" variant, but in addition, assumes that the
single argument is an immortal such as <&PL_sv_undef> and, for efficiency, will skip
incrementing its reference count.
void rpp_replace_2_1(SV *sv)
"rpp_stack_is_rc"
NOTE: "rpp_stack_is_rc" is experimental and may change or be removed without notice.
Returns a boolean value indicating whether the stack is currently reference-counted.
Note that if the stack is split (bottom half RC, top half non-RC), this function
returns false, even if the top half currently contains zero items.
bool rpp_stack_is_rc()
"rpp_try_AMAGIC_1"
"rpp_try_AMAGIC_2"
NOTE: both forms are experimental and may change or be removed without notice.
Check whether either of the one or two SVs at the top of the stack is magical or a
ref, and in either case handle it specially: invoke get magic, call an overload
method, or replace a ref with a temporary numeric value, as appropriate. If this
function returns true, it indicates that the correct return value is already on the
stack. Intended to be used at the beginning of the PP function for unary or binary
ops.
bool rpp_try_AMAGIC_1(int method, int flags)
"XSPP_wrapped"
NOTE: "XSPP_wrapped" is experimental and may change or be removed without notice.
Declare and wrap a non-reference-counted PP-style function. On traditional perl
builds where the stack isn't reference-counted, this just produces a function
declaration like
OP * xsppw_name(pTHX)
Conversely, in ref-counted builds it creates xsppw_name() as a small wrapper function
which calls the real function via a wrapper which processes the args and return values
to ensure that reference counts are properly handled for code which uses old-style
dSP, PUSHs(), POPs() etc, which don't adjust the reference counts of the items they
manipulate.
xsppw_nargs indicates how many arguments the function consumes off the stack. It can
be a constant value or an expression, such as
((PL_op->op_flags & OPf_STACKED) ? 2 : 1)
Alternatively if xsppw_nlists is 1, it indicates that the PP function consumes a list
(or - rarely - if 2, consumes two lists, like pp_aassign()), as indicated by the top
markstack position.
This is intended as a temporary fix when converting XS code to run under PERL_RC_STACK
builds. In the longer term, the PP function should be rewritten to replace PUSHs() etc
with rpp_push_1() etc.
XSPP_wrapped(xsppw_name, I32 xsppw_nargs, I32 xsppw_nlists)
REGEXP Functions
"pregcomp"
Described in perlreguts.
REGEXP * pregcomp(SV * const pattern, const U32 flags)
"pregexec"
Described in perlreguts.
I32 pregexec(REGEXP * const prog, char *stringarg, char *strend,
char *strbeg, SSize_t minend, SV *screamer,
U32 nosave)
"re_compile"
Compile the regular expression pattern "pattern", returning a pointer to the compiled
object for later matching with the internal regex engine.
This function is typically used by a custom regexp engine ".comp()" function to hand
off to the core regexp engine those patterns it doesn't want to handle itself
(typically passing through the same flags it was called with). In almost all other
cases, a regexp should be compiled by calling ""pregcomp"" to compile using the
currently active regexp engine.
If "pattern" is already a "REGEXP", this function does nothing but return a pointer to
the input. Otherwise the PV is extracted and treated like a string representing a
pattern. See perlre.
The possible flags for "rx_flags" are documented in perlreapi. Their names all begin
with "RXf_".
REGEXP * re_compile(SV * const pattern, U32 orig_rx_flags)
"re_dup_guts"
Duplicate a regexp.
This routine is expected to clone a given regexp structure. It is only compiled under
USE_ITHREADS.
After all of the core data stored in struct regexp is duplicated the
"regexp_engine.dupe" method is used to copy any private data stored in the *pprivate
pointer. This allows extensions to handle any duplication they need to do.
void re_dup_guts(const REGEXP *sstr, REGEXP *dstr,
CLONE_PARAMS *param)
"REGEX_LOCALE_CHARSET"
Described in perlreapi.
"REGEXP"
Described in perlreapi.
"regexp_engine"
When a regexp is compiled, its "engine" field is then set to point at the appropriate
structure, so that when it needs to be used Perl can find the right routines to do so.
In order to install a new regexp handler, $^H{regcomp} is set to an integer which
(when casted appropriately) resolves to one of these structures. When compiling, the
"comp" method is executed, and the resulting "regexp" structure's engine field is
expected to point back at the same structure.
The pTHX_ symbol in the definition is a macro used by Perl under threading to provide
an extra argument to the routine holding a pointer back to the interpreter that is
executing the regexp. So under threading all routines get an extra argument.
"regexp_paren_pair"
Described in perlreapi.
"regmatch_info"
Some basic information about the current match that is created by Perl_regexec_flags
and then passed to regtry(), regmatch() etc. It is allocated as a local var on the
stack, so nothing should be stored in it that needs preserving or clearing up on
croak(). For that, see the aux_info and aux_info_eval members of the regmatch_state
union.
"REXEC_COPY_SKIP_POST"
"REXEC_COPY_SKIP_PRE"
"REXEC_COPY_STR"
Described in perlreapi.
"RXapif_ALL"
"RXapif_CLEAR"
"RXapif_DELETE"
"RXapif_EXISTS"
"RXapif_FETCH"
"RXapif_FIRSTKEY"
"RXapif_NEXTKEY"
"RXapif_ONE"
"RXapif_REGNAME"
"RXapif_REGNAMES"
"RXapif_REGNAMES_COUNT"
"RXapif_SCALAR"
"RXapif_STORE"
Described in perlreapi.
"RX_BUFF_IDX_CARET_FULLMATCH"
"RX_BUFF_IDX_CARET_POSTMATCH"
"RX_BUFF_IDX_CARET_PREMATCH"
"RX_BUFF_IDX_FULLMATCH"
"RX_BUFF_IDX_POSTMATCH"
"RX_BUFF_IDX_PREMATCH"
Described in perlreapi.
"RXf_NO_INPLACE_SUBST"
"RXf_NULL"
"RXf_SKIPWHITE"
"RXf_SPLIT"
"RXf_START_ONLY"
"RXf_WHITE"
Described in perlreapi.
"RXf_PMf_EXTENDED"
"RXf_PMf_FOLD"
"RXf_PMf_KEEPCOPY"
"RXf_PMf_MULTILINE"
"RXf_PMf_SINGLELINE"
Described in perlreapi.
"RX_MATCH_COPIED"
Described in perlreapi.
RX_MATCH_COPIED(const REGEXP * rx_sv)
"struct regexp"
Described in perlreapi.
"SvRX"
Convenience macro to get the REGEXP from a SV. This is approximately equivalent to
the following snippet:
if (SvMAGICAL(sv))
mg_get(sv);
if (SvROK(sv))
sv = MUTABLE_SV(SvRV(sv));
if (SvTYPE(sv) == SVt_REGEXP)
return (REGEXP*) sv;
"NULL" will be returned if a REGEXP* is not found.
REGEXP * SvRX(SV *sv)
"SvRXOK"
Returns a boolean indicating whether the SV (or the one it references) is a REGEXP.
If you want to do something with the REGEXP* later use SvRX instead and check for
NULL.
bool SvRXOK(SV* sv)
"SV_SAVED_COPY"
Described in perlreapi.
Reports and Formats
These are used in the simple report generation feature of Perl. See perlform.
"IoBOTTOM_GV"
Described in perlguts.
GV * IoBOTTOM_GV(IO *io)
"IoBOTTOM_NAME"
Described in perlguts.
char * IoBOTTOM_NAME(IO *io)
"IoFMT_GV"
Described in perlguts.
GV * IoFMT_GV(IO *io)
"IoFMT_NAME"
Described in perlguts.
char * IoFMT_NAME(IO *io)
"IoLINES"
Described in perlguts.
IV IoLINES(IO *io)
"IoLINES_LEFT"
Described in perlguts.
IV IoLINES_LEFT(IO *io)
"IoPAGE"
Described in perlguts.
IV IoPAGE(IO *io)
"IoPAGE_LEN"
Described in perlguts.
IV IoPAGE_LEN(IO *io)
"IoTOP_GV"
Described in perlguts.
GV * IoTOP_GV(IO *io)
"IoTOP_NAME"
Described in perlguts.
char * IoTOP_NAME(IO *io)
Signals
"HAS_SIGINFO_SI_ADDR"
This symbol, if defined, indicates that "siginfo_t" has the "si_addr" member
"HAS_SIGINFO_SI_BAND"
This symbol, if defined, indicates that "siginfo_t" has the "si_band" member
"HAS_SIGINFO_SI_ERRNO"
This symbol, if defined, indicates that "siginfo_t" has the "si_errno" member
"HAS_SIGINFO_SI_PID"
This symbol, if defined, indicates that "siginfo_t" has the "si_pid" member
"HAS_SIGINFO_SI_STATUS"
This symbol, if defined, indicates that "siginfo_t" has the "si_status" member
"HAS_SIGINFO_SI_UID"
This symbol, if defined, indicates that "siginfo_t" has the "si_uid" member
"HAS_SIGINFO_SI_VALUE"
This symbol, if defined, indicates that "siginfo_t" has the "si_value" member
"PERL_SIGNALS_UNSAFE_FLAG"
If this bit in "PL_signals" is set, the system is uing the pre-Perl 5.8 unsafe
signals. See "PERL_SIGNALS" in perlrun and "Deferred Signals (Safe Signals)" in
perlipc.
U32 PERL_SIGNALS_UNSAFE_FLAG
"rsignal"
A wrapper for the C library functions sigaction(2) or signal(2). Use this instead of
those libc functions, as the Perl version gives the safest available implementation,
and knows things that interact with the rest of the perl interpreter.
Sighandler_t rsignal(int i, Sighandler_t t)
"rsignal_state"
Returns a the current signal handler for signal "signo". See ""rsignal"".
Sighandler_t rsignal_state(int i)
"Sigjmp_buf"
This is the buffer type to be used with Sigsetjmp and Siglongjmp.
"Siglongjmp"
This macro is used in the same way as siglongjmp(), but will invoke traditional
longjmp() if siglongjmp isn't available. See "HAS_SIGSETJMP".
void Siglongjmp(jmp_buf env, int val)
"SIG_NAME"
This symbol contains a list of signal names in order of signal number. This is
intended to be used as a static array initialization, like this:
char *sig_name[] = { SIG_NAME };
The signals in the list are separated with commas, and each signal is surrounded by
double quotes. There is no leading "SIG" in the signal name, i.e. "SIGQUIT" is known
as ""QUIT"". Gaps in the signal numbers (up to "NSIG") are filled in with "NUMnn",
etc., where nn is the actual signal number (e.g. "NUM37"). The signal number for
"sig_name[i]" is stored in "sig_num[i]". The last element is 0 to terminate the list
with a "NULL". This corresponds to the 0 at the end of the "sig_name_init" list.
Note that this variable is initialized from the "sig_name_init", not from "sig_name"
(which is unused).
"SIG_NUM"
This symbol contains a list of signal numbers, in the same order as the "SIG_NAME"
list. It is suitable for static array initialization, as in:
int sig_num[] = { SIG_NUM };
The signals in the list are separated with commas, and the indices within that list
and the "SIG_NAME" list match, so it's easy to compute the signal name from a number
or vice versa at the price of a small dynamic linear lookup. Duplicates are allowed,
but are moved to the end of the list. The signal number corresponding to
"sig_name[i]" is "sig_number[i]". if (i < "NSIG") then "sig_number[i]" == i. The
last element is 0, corresponding to the 0 at the end of the "sig_name_init" list.
Note that this variable is initialized from the "sig_num_init", not from "sig_num"
(which is unused).
"Sigsetjmp"
This macro is used in the same way as sigsetjmp(), but will invoke traditional
setjmp() if sigsetjmp isn't available. See "HAS_SIGSETJMP".
int Sigsetjmp(jmp_buf env, int savesigs)
"SIG_SIZE"
This variable contains the number of elements of the "SIG_NAME" and "SIG_NUM" arrays,
excluding the final "NULL" entry.
"whichsig"
"whichsig_pv"
"whichsig_pvn"
"whichsig_sv"
These all convert a signal name into its corresponding signal number; returning -1 if
no corresponding number was found.
They differ only in the source of the signal name:
"whichsig_pv" takes the name from the "NUL"-terminated string starting at "sig".
"whichsig" is merely a different spelling, a synonym, of "whichsig_pv".
"whichsig_pvn" takes the name from the string starting at "sig", with length "len"
bytes.
"whichsig_sv" takes the name from the PV stored in the SV "sigsv".
I32 whichsig (const char *sig)
I32 whichsig_pv (const char *sig)
I32 whichsig_pvn(const char *sig, STRLEN len)
I32 whichsig_sv (SV *sigsv)
Site configuration
These variables give details as to where various libraries, installation destinations,
etc., go, as well as what various installation options were selected
"ARCHLIB"
This variable, if defined, holds the name of the directory in which the user wants to
put architecture-dependent public library files for perl5. It is most often a local
directory such as /usr/local/lib. Programs using this variable must be prepared to
deal with filename expansion. If "ARCHLIB" is the same as "PRIVLIB", it is not
defined, since presumably the program already searches "PRIVLIB".
"ARCHLIB_EXP"
This symbol contains the ~name expanded version of "ARCHLIB", to be used in programs
that are not prepared to deal with ~ expansion at run-time.
"ARCHNAME"
This symbol holds a string representing the architecture name. It may be used to
construct an architecture-dependant pathname where library files may be held under a
private library, for instance.
"BIN"
This symbol holds the path of the bin directory where the package will be installed.
Program must be prepared to deal with ~name substitution.
"BIN_EXP"
This symbol is the filename expanded version of the "BIN" symbol, for programs that do
not want to deal with that at run-time.
"INSTALL_USR_BIN_PERL"
This symbol, if defined, indicates that Perl is to be installed also as /usr/bin/perl.
"MULTIARCH"
This symbol, if defined, signifies that the build process will produce some binary
files that are going to be used in a cross-platform environment. This is the case for
example with the NeXT "fat" binaries that contain executables for several "CPUs".
"PERL_INC_VERSION_LIST"
This variable specifies the list of subdirectories in over which perl.c:incpush() and
lib/lib.pm will automatically search when adding directories to @"INC", in a format
suitable for a C initialization string. See the "inc_version_list" entry in
Porting/Glossary for more details.
"PERL_OTHERLIBDIRS"
This variable contains a colon-separated set of paths for the perl binary to search
for additional library files or modules. These directories will be tacked to the end
of @"INC". Perl will automatically search below each path for version- and
architecture-specific directories. See "PERL_INC_VERSION_LIST" for more details.
"PERL_RELOCATABLE_INC"
This symbol, if defined, indicates that we'd like to relocate entries in @"INC" at run
time based on the location of the perl binary.
"PERL_TARGETARCH"
This symbol, if defined, indicates the target architecture Perl has been cross-
compiled to. Undefined if not a cross-compile.
"PERL_USE_DEVEL"
This symbol, if defined, indicates that Perl was configured with "-Dusedevel", to
enable development features. This should not be done for production builds.
"PERL_VENDORARCH"
If defined, this symbol contains the name of a private library. The library is
private in the sense that it needn't be in anyone's execution path, but it should be
accessible by the world. It may have a ~ on the front. The standard distribution
will put nothing in this directory. Vendors who distribute perl may wish to place
their own architecture-dependent modules and extensions in this directory with
MakeMaker Makefile.PL INSTALLDIRS=vendor
or equivalent. See "INSTALL" for details.
"PERL_VENDORARCH_EXP"
This symbol contains the ~name expanded version of "PERL_VENDORARCH", to be used in
programs that are not prepared to deal with ~ expansion at run-time.
"PERL_VENDORLIB_EXP"
This symbol contains the ~name expanded version of "VENDORLIB", to be used in programs
that are not prepared to deal with ~ expansion at run-time.
"PERL_VENDORLIB_STEM"
This define is "PERL_VENDORLIB_EXP" with any trailing version-specific component
removed. The elements in "inc_version_list" ("inc_version_list".U (part of
metaconfig)) can be tacked onto this variable to generate a list of directories to
search.
"PRIVLIB"
This symbol contains the name of the private library for this package. The library is
private in the sense that it needn't be in anyone's execution path, but it should be
accessible by the world. The program should be prepared to do ~ expansion.
"PRIVLIB_EXP"
This symbol contains the ~name expanded version of "PRIVLIB", to be used in programs
that are not prepared to deal with ~ expansion at run-time.
"SITEARCH"
This symbol contains the name of the private library for this package. The library is
private in the sense that it needn't be in anyone's execution path, but it should be
accessible by the world. The program should be prepared to do ~ expansion. The
standard distribution will put nothing in this directory. After perl has been
installed, users may install their own local architecture-dependent modules in this
directory with
MakeMaker Makefile.PL
or equivalent. See "INSTALL" for details.
"SITEARCH_EXP"
This symbol contains the ~name expanded version of "SITEARCH", to be used in programs
that are not prepared to deal with ~ expansion at run-time.
"SITELIB"
This symbol contains the name of the private library for this package. The library is
private in the sense that it needn't be in anyone's execution path, but it should be
accessible by the world. The program should be prepared to do ~ expansion. The
standard distribution will put nothing in this directory. After perl has been
installed, users may install their own local architecture-independent modules in this
directory with
MakeMaker Makefile.PL
or equivalent. See "INSTALL" for details.
"SITELIB_EXP"
This symbol contains the ~name expanded version of "SITELIB", to be used in programs
that are not prepared to deal with ~ expansion at run-time.
"SITELIB_STEM"
This define is "SITELIB_EXP" with any trailing version-specific component removed.
The elements in "inc_version_list" ("inc_version_list".U (part of metaconfig)) can be
tacked onto this variable to generate a list of directories to search.
"STARTPERL"
This variable contains the string to put in front of a perl script to make sure (one
hopes) that it runs with perl and not some shell.
"USE_64_BIT_ALL"
This symbol, if defined, indicates that 64-bit integers should be used when available.
If not defined, the native integers will be used (be they 32 or 64 bits). The maximal
possible 64-bitness is employed: LP64 or "ILP64", meaning that you will be able to use
more than 2 gigabytes of memory. This mode is even more binary incompatible than
"USE_64_BIT_INT". You may not be able to run the resulting executable in a 32-bit
"CPU" at all or you may need at least to reboot your OS to 64-bit mode.
"USE_64_BIT_INT"
This symbol, if defined, indicates that 64-bit integers should be used when available.
If not defined, the native integers will be employed (be they 32 or 64 bits). The
minimal possible 64-bitness is used, just enough to get 64-bit integers into Perl.
This may mean using for example "long longs", while your memory may still be limited
to 2 gigabytes.
"USE_BSD_GETPGRP"
This symbol, if defined, indicates that getpgrp needs one arguments whereas "USG" one
needs none.
"USE_BSD_SETPGRP"
This symbol, if defined, indicates that setpgrp needs two arguments whereas "USG" one
needs none. See also "HAS_SETPGID" for a "POSIX" interface.
"USE_C_BACKTRACE"
This symbol, if defined, indicates that Perl should be built with support for
backtrace.
"USE_CPLUSPLUS"
This symbol, if defined, indicates that a C++ compiler was used to compiled Perl and
will be used to compile extensions.
"USE_CROSS_COMPILE"
This symbol, if defined, indicates that Perl is being cross-compiled.
"USE_DTRACE"
This symbol, if defined, indicates that Perl should be built with support for DTrace.
"USE_DYNAMIC_LOADING"
This symbol, if defined, indicates that dynamic loading of some sort is available.
"USE_FAST_STDIO"
This symbol, if defined, indicates that Perl should be built to use 'fast stdio'.
Defaults to define in Perls 5.8 and earlier, to undef later.
"USE_ITHREADS"
This symbol, if defined, indicates that Perl should be built to use the interpreter-
based threading implementation.
"USE_KERN_PROC_PATHNAME"
This symbol, if defined, indicates that we can use sysctl with "KERN_PROC_PATHNAME" to
get a full path for the executable, and hence convert $^X to an absolute path.
"USE_LARGE_FILES"
This symbol, if defined, indicates that large file support should be used when
available.
"USE_LONG_DOUBLE"
This symbol, if defined, indicates that long doubles should be used when available.
"USE_MORE_BITS"
This symbol, if defined, indicates that 64-bit interfaces and long doubles should be
used when available.
"USE_NSGETEXECUTABLEPATH"
This symbol, if defined, indicates that we can use "_NSGetExecutablePath" and realpath
to get a full path for the executable, and hence convert $^X to an absolute path.
"USE_PERLIO"
This symbol, if defined, indicates that the PerlIO abstraction should be used
throughout. If not defined, stdio should be used in a fully backward compatible
manner.
"USE_QUADMATH"
This symbol, if defined, indicates that the quadmath library should be used when
available.
"USE_REENTRANT_API"
This symbol, if defined, indicates that Perl should try to use the various "_r"
versions of library functions. This is extremely experimental.
"USE_SEMCTL_SEMID_DS"
This symbol, if defined, indicates that "struct semid_ds" * is used for semctl
"IPC_STAT".
"USE_SEMCTL_SEMUN"
This symbol, if defined, indicates that "union semun" is used for semctl "IPC_STAT".
"USE_SITECUSTOMIZE"
This symbol, if defined, indicates that sitecustomize should be used.
"USE_SOCKS"
This symbol, if defined, indicates that Perl should be built to use socks.
"USE_STAT_BLOCKS"
This symbol is defined if this system has a stat structure declaring "st_blksize" and
"st_blocks".
"USE_STDIO_BASE"
This symbol is defined if the "_base" field (or similar) of the stdio "FILE" structure
can be used to access the stdio buffer for a file handle. If this is defined, then
the FILE_base(fp) macro will also be defined and should be used to access this field.
Also, the FILE_bufsiz(fp) macro will be defined and should be used to determine the
number of bytes in the buffer. "USE_STDIO_BASE" will never be defined unless
"USE_STDIO_PTR" is.
"USE_STDIO_PTR"
This symbol is defined if the "_ptr" and "_cnt" fields (or similar) of the stdio
"FILE" structure can be used to access the stdio buffer for a file handle. If this is
defined, then the FILE_ptr(fp) and FILE_cnt(fp) macros will also be defined and should
be used to access these fields.
"USE_STRICT_BY_DEFAULT"
This symbol, if defined, enables additional defaults. At this time it only enables
implicit strict by default.
"USE_THREADS"
This symbol, if defined, indicates that Perl should be built to use threads. At
present, it is a synonym for and "USE_ITHREADS", but eventually the source ought to be
changed to use this to mean "_any_" threading implementation.
Sockets configuration values
"HAS_SOCKADDR_IN6"
This symbol, if defined, indicates the availability of "struct sockaddr_in6";
"HAS_SOCKADDR_SA_LEN"
This symbol, if defined, indicates that the "struct sockaddr" structure has a member
called "sa_len", indicating the length of the structure.
"HAS_SOCKADDR_STORAGE"
This symbol, if defined, indicates the availability of "struct sockaddr_storage";
"HAS_SOCKATMARK"
This symbol, if defined, indicates that the "sockatmark" routine is available to test
whether a socket is at the out-of-band mark.
"HAS_SOCKET"
This symbol, if defined, indicates that the "BSD" "socket" interface is supported.
"HAS_SOCKETPAIR"
This symbol, if defined, indicates that the "BSD" socketpair() call is supported.
"HAS_SOCKS5_INIT"
This symbol, if defined, indicates that the "socks5_init" routine is available to
initialize "SOCKS" 5.
"I_SOCKS"
This symbol, if defined, indicates that socks.h exists and should be included.
#ifdef I_SOCKS
#include <socks.h>
#endif
"I_SYS_SOCKIO"
This symbol, if defined, indicates the sys/sockio.h should be included to get socket
ioctl options, like "SIOCATMARK".
#ifdef I_SYS_SOCKIO
#include <sys_sockio.h>
#endif
Source Filters
"apply_builtin_cv_attributes"
Given an OP_LIST containing attribute definitions, filter it for known builtin
attributes to apply to the cv, returning a possibly-smaller list containing just the
remaining ones.
OP * apply_builtin_cv_attributes(CV *cv, OP *attrlist)
"filter_add"
Described in perlfilter.
SV * filter_add(filter_t funcp, SV *datasv)
"filter_del"
Delete most recently added instance of the filter function argument
void filter_del(filter_t funcp)
"filter_read"
Described in perlfilter.
I32 filter_read(int idx, SV *buf_sv, int maxlen)
"scan_vstring"
Returns a pointer to the next character after the parsed vstring, as well as updating
the passed in sv.
Function must be called like
sv = sv_2mortal(newSV(5));
s = scan_vstring(s,e,sv);
where s and e are the start and end of the string. The sv should already be large
enough to store the vstring passed in, for performance reasons.
This function may croak if fatal warnings are enabled in the calling scope, hence the
sv_2mortal in the example (to prevent a leak). Make sure to do SvREFCNT_inc
afterwards if you use sv_2mortal.
char * scan_vstring(const char *s, const char * const e, SV *sv)
"start_subparse"
Set things up for parsing a subroutine.
If "is_format" is non-zero, the input is to be considered a format sub (a specialised
sub used to implement perl's "format" feature); else a normal "sub".
"flags" are added to the flags for "PL_compcv". "flags" may include the
"CVf_IsMETHOD" bit, which causes the new subroutine to be a method.
This returns the value of "PL_savestack_ix" that was in effect upon entry to the
function;
I32 start_subparse(I32 is_format, U32 flags)
Stack Manipulation Macros
"dMARK"
Declare a stack marker variable, "mark", for the XSUB. See "MARK" and "dORIGMARK".
dMARK;
"dORIGMARK"
Saves the original stack mark for the XSUB. See "ORIGMARK".
dORIGMARK;
"dSP"
Declares a local copy of perl's stack pointer for the XSUB, available via the "SP"
macro. See "SP".
dSP;
"dTARGET"
Declare that this function uses "TARG", and initializes it
dTARGET;
"EXTEND"
Used to extend the argument stack for an XSUB's return values. Once used, guarantees
that there is room for at least "nitems" to be pushed onto the stack.
void EXTEND(SP, SSize_t nitems)
"MARK"
Stack marker variable for the XSUB. See "dMARK".
"mPUSHi"
Push an integer onto the stack. The stack must have room for this element. Does not
use "TARG". See also "PUSHi", "mXPUSHi" and "XPUSHi".
void mPUSHi(IV iv)
"mPUSHn"
Push a double onto the stack. The stack must have room for this element. Does not
use "TARG". See also "PUSHn", "mXPUSHn" and "XPUSHn".
void mPUSHn(NV nv)
"mPUSHp"
Push a string onto the stack. The stack must have room for this element. The "len"
indicates the length of the string. Does not use "TARG". See also "PUSHp", "mXPUSHp"
and "XPUSHp".
void mPUSHp(char* str, STRLEN len)
"mPUSHpvs"
A variation on "mPUSHp" that takes a literal string and calculates its size directly.
void mPUSHpvs("literal string")
"mPUSHs"
Push an SV onto the stack and mortalizes the SV. The stack must have room for this
element. Does not use "TARG". See also "PUSHs" and "mXPUSHs".
void mPUSHs(SV* sv)
"mPUSHu"
Push an unsigned integer onto the stack. The stack must have room for this element.
Does not use "TARG". See also "PUSHu", "mXPUSHu" and "XPUSHu".
void mPUSHu(UV uv)
"mXPUSHi"
Push an integer onto the stack, extending the stack if necessary. Does not use
"TARG". See also "XPUSHi", "mPUSHi" and "PUSHi".
void mXPUSHi(IV iv)
"mXPUSHn"
Push a double onto the stack, extending the stack if necessary. Does not use "TARG".
See also "XPUSHn", "mPUSHn" and "PUSHn".
void mXPUSHn(NV nv)
"mXPUSHp"
Push a string onto the stack, extending the stack if necessary. The "len" indicates
the length of the string. Does not use "TARG". See also "XPUSHp", "mPUSHp" and
"PUSHp".
void mXPUSHp(char* str, STRLEN len)
"mXPUSHpvs"
A variation on "mXPUSHp" that takes a literal string and calculates its size directly.
void mXPUSHpvs("literal string")
"mXPUSHs"
Push an SV onto the stack, extending the stack if necessary and mortalizes the SV.
Does not use "TARG". See also "XPUSHs" and "mPUSHs".
void mXPUSHs(SV* sv)
"mXPUSHu"
Push an unsigned integer onto the stack, extending the stack if necessary. Does not
use "TARG". See also "XPUSHu", "mPUSHu" and "PUSHu".
void mXPUSHu(UV uv)
"newXSproto"
Used by "xsubpp" to hook up XSUBs as Perl subs. Adds Perl prototypes to the subs.
"ORIGMARK"
The original stack mark for the XSUB. See "dORIGMARK".
"PL_markstack"
Described in perlguts.
"PL_markstack_ptr"
Described in perlguts.
"PL_savestack"
Described in perlguts.
"PL_savestack_ix"
Described in perlguts.
"PL_scopestack"
Described in perlguts.
"PL_scopestack_ix"
Described in perlguts.
"PL_scopestack_name"
Described in perlguts.
"PL_stack_base"
Described in perlguts.
"PL_stack_sp"
Described in perlguts.
"PL_tmps_floor"
Described in perlguts.
"PL_tmps_ix"
Described in perlguts.
"PL_tmps_stack"
Described in perlguts.
"POPi"
Pops an integer off the stack.
IV POPi
"POPl"
Pops a long off the stack.
long POPl
"POPn"
Pops a double off the stack.
NV POPn
"POPp"
Pops a string off the stack.
char* POPp
"POPpbytex"
Pops a string off the stack which must consist of bytes i.e. characters < 256.
char* POPpbytex
"POPpx"
Pops a string off the stack. Identical to POPp. There are two names for historical
reasons.
char* POPpx
"POPs"
Pops an SV off the stack.
SV* POPs
"POPu"
Pops an unsigned integer off the stack.
UV POPu
"POPul"
Pops an unsigned long off the stack.
long POPul
"PUSHi"
Push an integer onto the stack. The stack must have room for this element. Handles
'set' magic. Uses "TARG", so "dTARGET" or "dXSTARG" should be called to declare it.
Do not call multiple "TARG"-oriented macros to return lists from XSUB's - see "mPUSHi"
instead. See also "XPUSHi" and "mXPUSHi".
void PUSHi(IV iv)
"PUSHMARK"
Opening bracket for arguments on a callback. See "PUTBACK" and perlcall.
void PUSHMARK(SP)
"PUSHmortal"
Push a new mortal SV onto the stack. The stack must have room for this element. Does
not use "TARG". See also "PUSHs", "XPUSHmortal" and "XPUSHs".
void PUSHmortal
"PUSHn"
Push a double onto the stack. The stack must have room for this element. Handles
'set' magic. Uses "TARG", so "dTARGET" or "dXSTARG" should be called to declare it.
Do not call multiple "TARG"-oriented macros to return lists from XSUB's - see "mPUSHn"
instead. See also "XPUSHn" and "mXPUSHn".
void PUSHn(NV nv)
"PUSHp"
Push a string onto the stack. The stack must have room for this element. The "len"
indicates the length of the string. Handles 'set' magic. Uses "TARG", so "dTARGET"
or "dXSTARG" should be called to declare it. Do not call multiple "TARG"-oriented
macros to return lists from XSUB's - see "mPUSHp" instead. See also "XPUSHp" and
"mXPUSHp".
void PUSHp(char* str, STRLEN len)
"PUSHpvs"
A variation on "PUSHp" that takes a literal string and calculates its size directly.
void PUSHpvs("literal string")
"PUSHs"
Push an SV onto the stack. The stack must have room for this element. Does not
handle 'set' magic. Does not use "TARG". See also "PUSHmortal", "XPUSHs", and
"XPUSHmortal".
void PUSHs(SV* sv)
"PUSHu"
Push an unsigned integer onto the stack. The stack must have room for this element.
Handles 'set' magic. Uses "TARG", so "dTARGET" or "dXSTARG" should be called to
declare it. Do not call multiple "TARG"-oriented macros to return lists from XSUB's -
see "mPUSHu" instead. See also "XPUSHu" and "mXPUSHu".
void PUSHu(UV uv)
"PUTBACK"
Closing bracket for XSUB arguments. This is usually handled by "xsubpp". See
"PUSHMARK" and perlcall for other uses.
PUTBACK;
"SAVEt_INT"
Described in perlguts.
"SP"
Stack pointer. This is usually handled by "xsubpp". See "dSP" and "SPAGAIN".
"SPAGAIN"
Refetch the stack pointer. Used after a callback. See perlcall.
SPAGAIN;
"SSNEW"
"SSNEWa"
"SSNEWat"
"SSNEWt"
These each temporarily allocate data on the savestack, returning an SSize_t index into
the savestack, because a pointer would get broken if the savestack is moved on
reallocation. Use ""SSPTR"" to convert the returned index into a pointer.
The forms differ in that plain "SSNEW" allocates "size" bytes; "SSNEWt" and "SSNEWat"
allocate "size" objects, each of which is type "type"; and <SSNEWa> and "SSNEWat" make
sure to align the new data to an "align" boundary. The most useful value for the
alignment is likely to be ""MEM_ALIGNBYTES"". The alignment will be preserved through
savestack reallocation only if realloc returns data aligned to a size divisible by
"align"!
SSize_t SSNEW (Size_t size)
SSize_t SSNEWa (Size_t size, Size_t align)
SSize_t SSNEWat(Size_t size, type, Size_t align)
SSize_t SSNEWt (Size_t size, type)
"SSPTR"
"SSPTRt"
These convert the "index" returned by L/<"SSNEW"> and kin into actual pointers.
The difference is that "SSPTR" casts the result to "type", and "SSPTRt" casts it to a
pointer of that "type".
type SSPTR (SSize_t index, type)
type * SSPTRt(SSize_t index, type)
"TARG"
"TARG" is short for "target". It is an entry in the pad that an OPs "op_targ" refers
to. It is scratchpad space, often used as a return value for the OP, but some use it
for other purposes.
TARG;
"TOPs"
Described in perlguts.
"XPUSHi"
Push an integer onto the stack, extending the stack if necessary. Handles 'set'
magic. Uses "TARG", so "dTARGET" or "dXSTARG" should be called to declare it. Do not
call multiple "TARG"-oriented macros to return lists from XSUB's - see "mXPUSHi"
instead. See also "PUSHi" and "mPUSHi".
void XPUSHi(IV iv)
"XPUSHmortal"
Push a new mortal SV onto the stack, extending the stack if necessary. Does not use
"TARG". See also "XPUSHs", "PUSHmortal" and "PUSHs".
void XPUSHmortal
"XPUSHn"
Push a double onto the stack, extending the stack if necessary. Handles 'set' magic.
Uses "TARG", so "dTARGET" or "dXSTARG" should be called to declare it. Do not call
multiple "TARG"-oriented macros to return lists from XSUB's - see "mXPUSHn" instead.
See also "PUSHn" and "mPUSHn".
void XPUSHn(NV nv)
"XPUSHp"
Push a string onto the stack, extending the stack if necessary. The "len" indicates
the length of the string. Handles 'set' magic. Uses "TARG", so "dTARGET" or
"dXSTARG" should be called to declare it. Do not call multiple "TARG"-oriented macros
to return lists from XSUB's - see "mXPUSHp" instead. See also "PUSHp" and "mPUSHp".
void XPUSHp(char* str, STRLEN len)
"XPUSHpvs"
A variation on "XPUSHp" that takes a literal string and calculates its size directly.
void XPUSHpvs("literal string")
"XPUSHs"
Push an SV onto the stack, extending the stack if necessary. Does not handle 'set'
magic. Does not use "TARG". See also "XPUSHmortal", "PUSHs" and "PUSHmortal".
void XPUSHs(SV* sv)
"XPUSHu"
Push an unsigned integer onto the stack, extending the stack if necessary. Handles
'set' magic. Uses "TARG", so "dTARGET" or "dXSTARG" should be called to declare it.
Do not call multiple "TARG"-oriented macros to return lists from XSUB's - see
"mXPUSHu" instead. See also "PUSHu" and "mPUSHu".
void XPUSHu(UV uv)
"XS_APIVERSION_BOOTCHECK"
Macro to verify that the perl api version an XS module has been compiled against
matches the api version of the perl interpreter it's being loaded into.
XS_APIVERSION_BOOTCHECK;
"XSRETURN"
Return from XSUB, indicating number of items on the stack. This is usually handled by
"xsubpp".
void XSRETURN(int nitems)
"XSRETURN_EMPTY"
Return an empty list from an XSUB immediately.
XSRETURN_EMPTY;
"XSRETURN_IV"
Return an integer from an XSUB immediately. Uses "XST_mIV".
void XSRETURN_IV(IV iv)
"XSRETURN_NO"
Return &PL_sv_no from an XSUB immediately. Uses "XST_mNO".
XSRETURN_NO;
"XSRETURN_NV"
Return a double from an XSUB immediately. Uses "XST_mNV".
void XSRETURN_NV(NV nv)
"XSRETURN_PV"
Return a copy of a string from an XSUB immediately. Uses "XST_mPV".
void XSRETURN_PV(char* str)
"XSRETURN_UNDEF"
Return &PL_sv_undef from an XSUB immediately. Uses "XST_mUNDEF".
XSRETURN_UNDEF;
"XSRETURN_UV"
Return an integer from an XSUB immediately. Uses "XST_mUV".
void XSRETURN_UV(IV uv)
"XSRETURN_YES"
Return &PL_sv_yes from an XSUB immediately. Uses "XST_mYES".
XSRETURN_YES;
"XST_mIV"
Place an integer into the specified position "pos" on the stack. The value is stored
in a new mortal SV.
void XST_mIV(int pos, IV iv)
"XST_mNO"
Place &PL_sv_no into the specified position "pos" on the stack.
void XST_mNO(int pos)
"XST_mNV"
Place a double into the specified position "pos" on the stack. The value is stored in
a new mortal SV.
void XST_mNV(int pos, NV nv)
"XST_mPV"
Place a copy of a string into the specified position "pos" on the stack. The value is
stored in a new mortal SV.
void XST_mPV(int pos, char* str)
"XST_mUNDEF"
Place &PL_sv_undef into the specified position "pos" on the stack.
void XST_mUNDEF(int pos)
"XST_mUV"
Place an unsigned integer into the specified position "pos" on the stack. The value
is stored in a new mortal SV.
void XST_mUV(int pos, UV uv)
"XST_mYES"
Place &PL_sv_yes into the specified position "pos" on the stack.
void XST_mYES(int pos)
"XS_VERSION"
The version identifier for an XS module. This is usually handled automatically by
"ExtUtils::MakeMaker". See "XS_VERSION_BOOTCHECK".
"XS_VERSION_BOOTCHECK"
Macro to verify that a PM module's $VERSION variable matches the XS module's
"XS_VERSION" variable. This is usually handled automatically by "xsubpp". See "The
VERSIONCHECK: Keyword" in perlxs.
XS_VERSION_BOOTCHECK;
String Handling
See also "Unicode Support".
"CAT2"
This macro concatenates 2 tokens together.
token CAT2(token x, token y)
"Copy"
"CopyD"
The XSUB-writer's interface to the C "memcpy" function. The "src" is the source,
"dest" is the destination, "nitems" is the number of items, and "type" is the type.
May fail on overlapping copies. See also "Move".
"CopyD" is like "Copy" but returns "dest". Useful for encouraging compilers to tail-
call optimise.
void Copy (void* src, void* dest, int nitems, type)
void * CopyD(void* src, void* dest, int nitems, type)
"delimcpy"
Copy a source buffer to a destination buffer, stopping at (but not including) the
first occurrence in the source of an unescaped (defined below) delimiter byte,
"delim". The source is the bytes between "from" and "from_end" - 1. Similarly, the
dest is "to" up to "to_end".
The number of bytes copied is written to *retlen.
Returns the position of the first uncopied "delim" in the "from" buffer, but if there
is no such occurrence before "from_end", then "from_end" is returned, and the entire
buffer "from" .. "from_end" - 1 is copied.
If there is room in the destination available after the copy, an extra terminating
safety "NUL" byte is appended (not included in the returned length).
The error case is if the destination buffer is not large enough to accommodate
everything that should be copied. In this situation, a value larger than
"to_end" - "to" is written to *retlen, and as much of the source as fits will be
written to the destination. Not having room for the safety "NUL" is not considered an
error.
In the following examples, let "x" be the delimiter, and 0 represent a "NUL" byte (NOT
the digit 0). Then we would have
Source Destination
abcxdef abc0
provided the destination buffer is at least 4 bytes long.
An escaped delimiter is one which is immediately preceded by a single backslash.
Escaped delimiters are copied, and the copy continues past the delimiter; the
backslash is not copied:
Source Destination
abc\xdef abcxdef0
(provided the destination buffer is at least 8 bytes long).
It's actually somewhat more complicated than that. A sequence of any odd number of
backslashes escapes the following delimiter, and the copy continues with exactly one
of the backslashes stripped.
Source Destination
abc\xdef abcxdef0
abc\\\xdef abc\\xdef0
abc\\\\\xdef abc\\\\xdef0
(as always, if the destination is large enough)
An even number of preceding backslashes does not escape the delimiter, so that the
copy stops just before it, and includes all the backslashes (no stripping; zero is
considered even):
Source Destination
abcxdef abc0
abc\\xdef abc\\0
abc\\\\xdef abc\\\\0
char * delimcpy(char *to, const char *to_end, const char *from,
const char *from_end, const int delim,
I32 *retlen)
"do_join"
This performs a Perl "join", placing the joined output into "sv".
The elements to join are in SVs, stored in a C array of pointers to SVs, from **mark
to "**sp - 1". Hence *mark is a reference to the first SV. Each SV will be coerced
into a PV if not one already.
"delim" contains the string (or coerced into a string) that is to separate each of the
joined elements.
If any component is in UTF-8, the result will be as well, and all non-UTF-8 components
will be converted to UTF-8 as necessary.
Magic and tainting are handled.
void do_join(SV *sv, SV *delim, SV **mark, SV **sp)
"do_sprintf"
This performs a Perl "sprintf" placing the string output into "sv".
The elements to format are in SVs, stored in a C array of pointers to SVs of length
"len"> and beginning at **sarg. The element referenced by *sarg is the format.
Magic and tainting are handled.
void do_sprintf(SV *sv, SSize_t len, SV **sarg)
"fbm_compile"
Analyzes the string in order to make fast searches on it using fbm_instr() -- the
Boyer-Moore algorithm.
void fbm_compile(SV *sv, U32 flags)
"fbm_instr"
Returns the location of the SV in the string delimited by "big" and "bigend"
("bigend") is the char following the last char). It returns "NULL" if the string
can't be found. The "sv" does not have to be "fbm_compiled", but the search will not
be as fast then.
char * fbm_instr(unsigned char *big, unsigned char *bigend,
SV *littlestr, U32 flags)
"foldEQ"
Returns true if the leading "len" bytes of the strings "s1" and "s2" are the same
case-insensitively; false otherwise. Uppercase and lowercase ASCII range bytes match
themselves and their opposite case counterparts. Non-cased and non-ASCII range bytes
match only themselves.
I32 foldEQ(const char *a, const char *b, I32 len)
"ibcmp"
This is a synonym for "(! foldEQ())"
I32 ibcmp(const char *a, const char *b, I32 len)
"ibcmp_locale"
This is a synonym for "(! foldEQ_locale())"
I32 ibcmp_locale(const char *a, const char *b, I32 len)
"ibcmp_utf8"
This is a synonym for "(! foldEQ_utf8())"
I32 ibcmp_utf8(const char *s1, char **pe1, UV l1, bool u1,
const char *s2, char **pe2, UV l2, bool u2)
"instr"
Same as strstr(3), which finds and returns a pointer to the first occurrence of the
NUL-terminated substring "little" in the NUL-terminated string "big", returning NULL
if not found. The terminating NUL bytes are not compared.
char * instr(const char *big, const char *little)
"memCHRs"
Returns the position of the first occurrence of the byte "c" in the literal string
"list", or NULL if "c" doesn't appear in "list". All bytes are treated as unsigned
char. Thus this macro can be used to determine if "c" is in a set of particular
characters. Unlike strchr(3), it works even if "c" is "NUL" (and the set doesn't
include "NUL").
bool memCHRs("list", char c)
"memEQ"
Test two buffers (which may contain embedded "NUL" characters, to see if they are
equal. The "len" parameter indicates the number of bytes to compare. Returns true or
false. It is undefined behavior if either of the buffers doesn't contain at least
"len" bytes.
bool memEQ(char* s1, char* s2, STRLEN len)
"memEQs"
Like "memEQ", but the second string is a literal enclosed in double quotes, "l1" gives
the number of bytes in "s1". Returns true or false.
bool memEQs(char* s1, STRLEN l1, "s2")
"memNE"
Test two buffers (which may contain embedded "NUL" characters, to see if they are not
equal. The "len" parameter indicates the number of bytes to compare. Returns true or
false. It is undefined behavior if either of the buffers doesn't contain at least
"len" bytes.
bool memNE(char* s1, char* s2, STRLEN len)
"memNEs"
Like "memNE", but the second string is a literal enclosed in double quotes, "l1" gives
the number of bytes in "s1". Returns true or false.
bool memNEs(char* s1, STRLEN l1, "s2")
"Move"
"MoveD"
The XSUB-writer's interface to the C "memmove" function. The "src" is the source,
"dest" is the destination, "nitems" is the number of items, and "type" is the type.
Can do overlapping moves. See also "Copy".
"MoveD" is like "Move" but returns "dest". Useful for encouraging compilers to tail-
call optimise.
void Move (void* src, void* dest, int nitems, type)
void * MoveD(void* src, void* dest, int nitems, type)
"my_snprintf"
The C library "snprintf" functionality, if available and standards-compliant (uses
"vsnprintf", actually). However, if the "vsnprintf" is not available, will
unfortunately use the unsafe "vsprintf" which can overrun the buffer (there is an
overrun check, but that may be too late). Consider using "sv_vcatpvf" instead, or
getting "vsnprintf".
int my_snprintf(char *buffer, const Size_t len,
const char *format, ...)
"my_sprintf"
"DEPRECATED!" It is planned to remove "my_sprintf" from a future release of Perl. Do
not use it for new code; remove it from existing code.
Do NOT use this due to the possibility of overflowing "buffer". Instead use
my_snprintf()
int my_sprintf(NN char *buffer, NN const char *pat, ...)
"my_strnlen"
The C library "strnlen" if available, or a Perl implementation of it.
my_strnlen() computes the length of the string, up to "maxlen" bytes. It will never
attempt to address more than "maxlen" bytes, making it suitable for use with strings
that are not guaranteed to be NUL-terminated.
Size_t my_strnlen(const char *str, Size_t maxlen)
"my_vsnprintf"
The C library "vsnprintf" if available and standards-compliant. However, if the
"vsnprintf" is not available, will unfortunately use the unsafe "vsprintf" which can
overrun the buffer (there is an overrun check, but that may be too late). Consider
using "sv_vcatpvf" instead, or getting "vsnprintf".
int my_vsnprintf(char *buffer, const Size_t len,
const char *format, va_list ap)
"NewCopy"
Combines Newx() and Copy() into a single macro. Dest will be allocated using Newx()
and then src will be copied into it.
void NewCopy(void* src, void* dest, int nitems, type)
"ninstr"
Find the first (leftmost) occurrence of a sequence of bytes within another sequence.
This is the Perl version of strstr(), extended to handle arbitrary sequences,
potentially containing embedded "NUL" characters ("NUL" is what the initial "n" in the
function name stands for; some systems have an equivalent, memmem(), but with a
somewhat different API).
Another way of thinking about this function is finding a needle in a haystack. "big"
points to the first byte in the haystack. "big_end" points to one byte beyond the
final byte in the haystack. "little" points to the first byte in the needle.
"little_end" points to one byte beyond the final byte in the needle. All the
parameters must be non-"NULL".
The function returns "NULL" if there is no occurrence of "little" within "big". If
"little" is the empty string, "big" is returned.
Because this function operates at the byte level, and because of the inherent
characteristics of UTF-8 (or UTF-EBCDIC), it will work properly if both the needle and
the haystack are strings with the same UTF-8ness, but not if the UTF-8ness differs.
char * ninstr(const char *big, const char *bigend,
const char *little, const char *lend)
"Nullch"
Null character pointer. (No longer available when "PERL_CORE" is defined.)
"PL_na"
A scratch pad variable in which to store a "STRLEN" value. If would have been better
named something like "PL_temp_strlen".
It is is typically used with "SvPV" when one is actually planning to discard the
returned length, (hence the length is "Not Applicable", which is how this variable got
its name).
BUT BEWARE, if this is used in a situation where something that is using it is in a
call stack with something else that is using it, this variable would get zapped,
leading to hard-to-diagnose errors.
It is usually more efficient to either declare a local variable and use that instead,
or to use the "SvPV_nolen" macro.
STRLEN PL_na
"rninstr"
Like "ninstr", but instead finds the final (rightmost) occurrence of a sequence of
bytes within another sequence, returning "NULL" if there is no such occurrence.
char * rninstr(const char *big, const char *bigend,
const char *little, const char *lend)
"savepv"
Perl's version of strdup(). Returns a pointer to a newly allocated string which is a
duplicate of "pv". The size of the string is determined by strlen(), which means it
may not contain embedded "NUL" characters and must have a trailing "NUL". To prevent
memory leaks, the memory allocated for the new string needs to be freed when no longer
needed. This can be done with the "Safefree" function, or "SAVEFREEPV".
On some platforms, Windows for example, all allocated memory owned by a thread is
deallocated when that thread ends. So if you need that not to happen, you need to use
the shared memory functions, such as "savesharedpv".
char * savepv(const char *pv)
"savepvn"
Perl's version of what strndup() would be if it existed. Returns a pointer to a newly
allocated string which is a duplicate of the first "len" bytes from "pv", plus a
trailing "NUL" byte. The memory allocated for the new string can be freed with the
Safefree() function.
On some platforms, Windows for example, all allocated memory owned by a thread is
deallocated when that thread ends. So if you need that not to happen, you need to use
the shared memory functions, such as "savesharedpvn".
char * savepvn(const char *pv, Size_t len)
"savepvs"
Like "savepvn", but takes a literal string instead of a string/length pair.
char* savepvs("literal string")
"savesharedpv"
A version of savepv() which allocates the duplicate string in memory which is shared
between threads.
char * savesharedpv(const char *pv)
"savesharedpvn"
A version of savepvn() which allocates the duplicate string in memory which is shared
between threads. (With the specific difference that a "NULL" pointer is not
acceptable)
char * savesharedpvn(const char * const pv, const STRLEN len)
"savesharedpvs"
A version of savepvs() which allocates the duplicate string in memory which is shared
between threads.
char* savesharedpvs("literal string")
"savesharedsvpv"
A version of savesharedpv() which allocates the duplicate string in memory which is
shared between threads.
char * savesharedsvpv(SV *sv)
"savesvpv"
A version of savepv()/savepvn() which gets the string to duplicate from the passed in
SV using SvPV()
On some platforms, Windows for example, all allocated memory owned by a thread is
deallocated when that thread ends. So if you need that not to happen, you need to use
the shared memory functions, such as "savesharedsvpv".
char * savesvpv(SV *sv)
"strEQ"
Test two "NUL"-terminated strings to see if they are equal. Returns true or false.
bool strEQ(char* s1, char* s2)
"strGE"
Test two "NUL"-terminated strings to see if the first, "s1", is greater than or equal
to the second, "s2". Returns true or false.
bool strGE(char* s1, char* s2)
"strGT"
Test two "NUL"-terminated strings to see if the first, "s1", is greater than the
second, "s2". Returns true or false.
bool strGT(char* s1, char* s2)
"STRINGIFY"
This macro surrounds its token with double quotes.
string STRINGIFY(token x)
"strLE"
Test two "NUL"-terminated strings to see if the first, "s1", is less than or equal to
the second, "s2". Returns true or false.
bool strLE(char* s1, char* s2)
"STRLEN"
Described in perlguts.
"strLT"
Test two "NUL"-terminated strings to see if the first, "s1", is less than the second,
"s2". Returns true or false.
bool strLT(char* s1, char* s2)
"strNE"
Test two "NUL"-terminated strings to see if they are different. Returns true or
false.
bool strNE(char* s1, char* s2)
"strnEQ"
Test two "NUL"-terminated strings to see if they are equal. The "len" parameter
indicates the number of bytes to compare. Returns true or false. (A wrapper for
"strncmp").
bool strnEQ(char* s1, char* s2, STRLEN len)
"strnNE"
Test two "NUL"-terminated strings to see if they are different. The "len" parameter
indicates the number of bytes to compare. Returns true or false. (A wrapper for
"strncmp").
bool strnNE(char* s1, char* s2, STRLEN len)
"STR_WITH_LEN"
Returns two comma separated tokens of the input literal string, and its length. This
is convenience macro which helps out in some API calls. Note that it can't be used as
an argument to macros or functions that under some configurations might be macros,
which means that it requires the full Perl_xxx(aTHX_ ...) form for any API calls where
it's used.
pair STR_WITH_LEN("literal string")
"Zero"
"ZeroD"
The XSUB-writer's interface to the C "memzero" function. The "dest" is the
destination, "nitems" is the number of items, and "type" is the type.
"ZeroD" is like "Zero" but returns "dest". Useful for encouraging compilers to tail-
call optimise.
void Zero (void* dest, int nitems, type)
void * ZeroD(void* dest, int nitems, type)
SV Flags
"SVt_IV"
Type flag for scalars. See "svtype".
"SVt_NULL"
Type flag for scalars. See "svtype".
"SVt_NV"
Type flag for scalars. See "svtype".
"SVt_PV"
Type flag for scalars. See "svtype".
"SVt_PVAV"
Type flag for arrays. See "svtype".
"SVt_PVCV"
Type flag for subroutines. See "svtype".
"SVt_PVFM"
Type flag for formats. See "svtype".
"SVt_PVGV"
Type flag for typeglobs. See "svtype".
"SVt_PVHV"
Type flag for hashes. See "svtype".
"SVt_PVIO"
Type flag for I/O objects. See "svtype".
"SVt_PVIV"
Type flag for scalars. See "svtype".
"SVt_PVLV"
Type flag for scalars. See "svtype".
"SVt_PVMG"
Type flag for scalars. See "svtype".
"SVt_PVNV"
Type flag for scalars. See "svtype".
"SVt_PVOBJ"
NOTE: "SVt_PVOBJ" is experimental and may change or be removed without notice.
Type flag for object instances. See "svtype".
"SVt_REGEXP"
Type flag for regular expressions. See "svtype".
"svtype"
An enum of flags for Perl types. These are found in the file sv.h in the "svtype"
enum. Test these flags with the "SvTYPE" macro.
The types are:
SVt_NULL
SVt_IV
SVt_NV
SVt_RV
SVt_PV
SVt_PVIV
SVt_PVNV
SVt_PVMG
SVt_INVLIST
SVt_REGEXP
SVt_PVGV
SVt_PVLV
SVt_PVAV
SVt_PVHV
SVt_PVCV
SVt_PVFM
SVt_PVIO
SVt_PVOBJ
These are most easily explained from the bottom up.
"SVt_PVOBJ" is for object instances of the new `use feature 'class'` kind. "SVt_PVIO"
is for I/O objects, "SVt_PVFM" for formats, "SVt_PVCV" for subroutines, "SVt_PVHV" for
hashes and "SVt_PVAV" for arrays.
All the others are scalar types, that is, things that can be bound to a "$" variable.
For these, the internal types are mostly orthogonal to types in the Perl language.
Hence, checking "SvTYPE(sv) < SVt_PVAV" is the best way to see whether something is a
scalar.
"SVt_PVGV" represents a typeglob. If "!SvFAKE(sv)", then it is a real, incoercible
typeglob. If SvFAKE(sv), then it is a scalar to which a typeglob has been assigned.
Assigning to it again will stop it from being a typeglob. "SVt_PVLV" represents a
scalar that delegates to another scalar behind the scenes. It is used, e.g., for the
return value of "substr" and for tied hash and array elements. It can hold any scalar
value, including a typeglob. "SVt_REGEXP" is for regular expressions. "SVt_INVLIST"
is for Perl core internal use only.
"SVt_PVMG" represents a "normal" scalar (not a typeglob, regular expression, or
delegate). Since most scalars do not need all the internal fields of a PVMG, we save
memory by allocating smaller structs when possible. All the other types are just
simpler forms of "SVt_PVMG", with fewer internal fields. "SVt_NULL" can only hold
undef. "SVt_IV" can hold undef, an integer, or a reference. ("SVt_RV" is an alias
for "SVt_IV", which exists for backward compatibility.) "SVt_NV" can hold undef or a
double. (In builds that support headless NVs, these could also hold a reference via a
suitable offset, in the same way that SVt_IV does, but this is not currently supported
and seems to be a rare use case.) "SVt_PV" can hold "undef", a string, or a reference.
"SVt_PVIV" is a superset of "SVt_PV" and "SVt_IV". "SVt_PVNV" is a superset of
"SVt_PV" and "SVt_NV". "SVt_PVMG" can hold anything "SVt_PVNV" can hold, but it may
also be blessed or magical.
SV Handling
"AV_FROM_REF"
"CV_FROM_REF"
"HV_FROM_REF"
The "*V_FROM_REF" macros extract the SvRV() from a given reference SV and return a
suitably-cast to pointer to the referenced SV. When running under "-DDEBUGGING",
assertions are also applied that check that ref is definitely a reference SV that
refers to an SV of the right type.
AV * AV_FROM_REF(SV * ref)
CV * CV_FROM_REF(SV * ref)
HV * HV_FROM_REF(SV * ref)
"BOOL_INTERNALS_sv_isbool"
Checks if a SvBoolFlagsOK() sv is a bool. Note that it is the caller's responsibility
to ensure that the sv is SvBoolFlagsOK() before calling this. This is only useful in
specialized logic like serialization code where performance is critical and the flags
have already been checked to be correct. Almost always you should be using
sv_isbool(sv) instead.
bool BOOL_INTERNALS_sv_isbool(SV* sv)
"BOOL_INTERNALS_sv_isbool_false"
Checks if a SvBoolFlagsOK() sv is a false bool. Note that it is the caller's
responsibility to ensure that the sv is SvBoolFlagsOK() before calling this. This is
only useful in specialized logic like serialization code where performance is critical
and the flags have already been checked to be correct. This is NOT what you should use
to check if an SV is "false", for that you should be using "!SvTRUE(sv)" instead.
bool BOOL_INTERNALS_sv_isbool_false(SV* sv)
"BOOL_INTERNALS_sv_isbool_true"
Checks if a SvBoolFlagsOK() sv is a true bool. Note that it is the caller's
responsibility to ensure that the sv is SvBoolFlagsOK() before calling this. This is
only useful in specialized logic like serialization code where performance is critical
and the flags have already been checked to be correct. This is NOT what you should use
to check if an SV is "true", for that you should be using SvTRUE(sv) instead.
bool BOOL_INTERNALS_sv_isbool_true(SV* sv)
"boolSV"
Returns a true SV if "b" is a true value, or a false SV if "b" is 0.
See also "PL_sv_yes" and "PL_sv_no".
SV * boolSV(bool b)
"croak_xs_usage"
A specialised variant of croak() for emitting the usage message for xsubs
croak_xs_usage(cv, "eee_yow");
works out the package name and subroutine name from "cv", and then calls croak().
Hence if "cv" is &ouch::awk, it would call "croak" as:
diag_listed_as: SKIPME
Perl_croak(aTHX_ "Usage: %" SVf "::%" SVf "(%s)", "ouch" "awk",
"eee_yow");
void croak_xs_usage(const CV * const cv,
const char * const params)
"DEFSV"
Returns the SV associated with $_
SV * DEFSV
"DEFSV_set"
Associate "sv" with $_
void DEFSV_set(SV * sv)
"get_sv"
Returns the SV of the specified Perl scalar. "flags" are passed to ""gv_fetchpv"".
If "GV_ADD" is set and the Perl variable does not exist then it will be created. If
"flags" is zero and the variable does not exist then NULL is returned.
NOTE: the perl_get_sv() form is deprecated.
SV * get_sv(const char *name, I32 flags)
"isGV_with_GP"
Returns a boolean as to whether or not "sv" is a GV with a pointer to a GP (glob
pointer).
bool isGV_with_GP(SV * sv)
"looks_like_number"
Test if the content of an SV looks like a number (or is a number). "Inf" and
"Infinity" are treated as numbers (so will not issue a non-numeric warning), even if
your atof() doesn't grok them. Get-magic is ignored.
I32 looks_like_number(SV * const sv)
"MUTABLE_AV"
"MUTABLE_CV"
"MUTABLE_GV"
"MUTABLE_HV"
"MUTABLE_IO"
"MUTABLE_PTR"
"MUTABLE_SV"
The "MUTABLE_*"() macros cast pointers to the types shown, in such a way (compiler
permitting) that casting away const-ness will give a warning; e.g.:
const SV *sv = ...;
AV *av1 = (AV*)sv; <== BAD: the const has been silently
cast away
AV *av2 = MUTABLE_AV(sv); <== GOOD: it may warn
"MUTABLE_PTR" is the base macro used to derive new casts. The other already-built-in
ones return pointers to what their names indicate.
AV * MUTABLE_AV (AV * p)
CV * MUTABLE_CV (CV * p)
GV * MUTABLE_GV (GV * p)
HV * MUTABLE_HV (HV * p)
IO * MUTABLE_IO (IO * p)
void * MUTABLE_PTR(void * p)
SV * MUTABLE_SV (SV * p)
"newRV"
"newRV_inc"
These are identical. They create an RV wrapper for an SV. The reference count for
the original SV is incremented.
SV * newRV(SV * const sv)
"newRV_noinc"
Creates an RV wrapper for an SV. The reference count for the original SV is not
incremented.
SV * newRV_noinc(SV * const tmpRef)
"newSV"
Creates a new SV. A non-zero "len" parameter indicates the number of bytes of
preallocated string space the SV should have. An extra byte for a trailing "NUL" is
also reserved. ("SvPOK" is not set for the SV even if string space is allocated.)
The reference count for the new SV is set to 1.
In 5.9.3, newSV() replaces the older NEWSV() API, and drops the first parameter, x, a
debug aid which allowed callers to identify themselves. This aid has been superseded
by a new build option, "PERL_MEM_LOG" (see "PERL_MEM_LOG" in perlhacktips). The older
API is still there for use in XS modules supporting older perls.
SV * newSV(const STRLEN len)
"newSVbool"
Creates a new SV boolean.
SV * newSVbool(const bool bool_val)
"newSV_false"
Creates a new SV that is a boolean false.
SV * newSV_false()
"newSVhek"
Creates a new SV from the hash key structure. It will generate scalars that point to
the shared string table where possible. Returns a new (undefined) SV if "hek" is
NULL.
SV * newSVhek(const HEK * const hek)
"newSVhek_mortal"
Creates a new mortal SV from the hash key structure. It will generate scalars that
point to the shared string table where possible. Returns a new (undefined) SV if
"hek" is NULL.
This is more efficient than using sv_2mortal(newSVhek( ... ))
SV * newSVhek_mortal(const HEK * const hek)
"newSViv"
Creates a new SV and copies an integer into it. The reference count for the SV is set
to 1.
SV * newSViv(const IV i)
"newSVnv"
Creates a new SV and copies a floating point value into it. The reference count for
the SV is set to 1.
SV * newSVnv(const NV n)
"newSVpadname"
NOTE: "newSVpadname" is experimental and may change or be removed without notice.
Creates a new SV containing the pad name.
SV* newSVpadname(PADNAME *pn)
"newSVpv"
Creates a new SV and copies a string (which may contain "NUL" ("\0") characters) into
it. The reference count for the SV is set to 1. If "len" is zero, Perl will compute
the length using strlen(), (which means if you use this option, that "s" can't have
embedded "NUL" characters and has to have a terminating "NUL" byte).
This function can cause reliability issues if you are likely to pass in empty strings
that are not null terminated, because it will run strlen on the string and potentially
run past valid memory.
Using "newSVpvn" is a safer alternative for non "NUL" terminated strings. For string
literals use "newSVpvs" instead. This function will work fine for "NUL" terminated
strings, but if you want to avoid the if statement on whether to call "strlen" use
"newSVpvn" instead (calling "strlen" yourself).
SV * newSVpv(const char * const s, const STRLEN len)
"newSVpvf"
Creates a new SV and initializes it with the string formatted like "sv_catpvf".
NOTE: "newSVpvf" must be explicitly called as "Perl_newSVpvf" with an "aTHX_"
parameter.
SV * Perl_newSVpvf(pTHX_ const char * const pat, ...)
"newSVpvf_nocontext"
Like "newSVpvf" but does not take a thread context ("aTHX") parameter, so is used in
situations where the caller doesn't already have the thread context.
SV * newSVpvf_nocontext(const char * const pat, ...)
"newSVpvn"
Creates a new SV and copies a string into it, which may contain "NUL" characters
("\0") and other binary data. The reference count for the SV is set to 1. Note that
if "len" is zero, Perl will create a zero length (Perl) string. You are responsible
for ensuring that the source buffer is at least "len" bytes long. If the "buffer"
argument is NULL the new SV will be undefined.
SV * newSVpvn(const char * const buffer, const STRLEN len)
"newSVpvn_flags"
Creates a new SV and copies a string (which may contain "NUL" ("\0") characters) into
it. The reference count for the SV is set to 1. Note that if "len" is zero, Perl
will create a zero length string. You are responsible for ensuring that the source
string is at least "len" bytes long. If the "s" argument is NULL the new SV will be
undefined. Currently the only flag bits accepted are "SVf_UTF8" and "SVs_TEMP". If
"SVs_TEMP" is set, then sv_2mortal() is called on the result before returning. If
"SVf_UTF8" is set, "s" is considered to be in UTF-8 and the "SVf_UTF8" flag will be
set on the new SV. newSVpvn_utf8() is a convenience wrapper for this function,
defined as
#define newSVpvn_utf8(s, len, u) \
newSVpvn_flags((s), (len), (u) ? SVf_UTF8 : 0)
SV * newSVpvn_flags(const char * const s, const STRLEN len,
const U32 flags)
"newSVpvn_share"
Creates a new SV with its "SvPVX_const" pointing to a shared string in the string
table. If the string does not already exist in the table, it is created first. Turns
on the "SvIsCOW" flag (or "READONLY" and "FAKE" in 5.16 and earlier). If the "hash"
parameter is non-zero, that value is used; otherwise the hash is computed. The
string's hash can later be retrieved from the SV with the "SvSHARED_HASH" macro. The
idea here is that as the string table is used for shared hash keys these strings will
have "SvPVX_const == HeKEY" and hash lookup will avoid string compare.
SV * newSVpvn_share(const char *s, I32 len, U32 hash)
"newSVpvn_utf8"
Creates a new SV and copies a string (which may contain "NUL" ("\0") characters) into
it. If "utf8" is true, calls "SvUTF8_on" on the new SV. Implemented as a wrapper
around "newSVpvn_flags".
SV* newSVpvn_utf8(const char* s, STRLEN len, U32 utf8)
"newSVpvs"
Like "newSVpvn", but takes a literal string instead of a string/length pair.
SV* newSVpvs("literal string")
"newSVpvs_flags"
Like "newSVpvn_flags", but takes a literal string instead of a string/length pair.
SV* newSVpvs_flags("literal string", U32 flags)
"newSVpv_share"
Like "newSVpvn_share", but takes a "NUL"-terminated string instead of a string/length
pair.
SV * newSVpv_share(const char *s, U32 hash)
"newSVpvs_share"
Like "newSVpvn_share", but takes a literal string instead of a string/length pair and
omits the hash parameter.
SV* newSVpvs_share("literal string")
"newSVrv"
Creates a new SV for the existing RV, "rv", to point to. If "rv" is not an RV then it
will be upgraded to one. If "classname" is non-null then the new SV will be blessed
in the specified package. The new SV is returned and its reference count is 1. The
reference count 1 is owned by "rv". See also newRV_inc() and newRV_noinc() for
creating a new RV properly.
SV * newSVrv(SV * const rv, const char * const classname)
"newSVsv"
"newSVsv_flags"
"newSVsv_nomg"
These create a new SV which is an exact duplicate of the original SV (using
"sv_setsv".)
They differ only in that "newSVsv" performs 'get' magic; "newSVsv_nomg" skips any
magic; and "newSVsv_flags" allows you to explicitly set a "flags" parameter.
SV * newSVsv (SV * const old)
SV * newSVsv_flags(SV * const old, I32 flags)
SV * newSVsv_nomg (SV * const old)
"newSV_true"
Creates a new SV that is a boolean true.
SV * newSV_true()
"newSV_type"
Creates a new SV, of the type specified. The reference count for the new SV is set to
1.
SV * newSV_type(const svtype type)
"newSV_type_mortal"
Creates a new mortal SV, of the type specified. The reference count for the new SV is
set to 1.
This is equivalent to
SV* sv = sv_2mortal(newSV_type(<some type>)) and
SV* sv = sv_newmortal();
sv_upgrade(sv, <some_type>) but should be more efficient than both of them.
(Unless sv_2mortal is inlined at some point in the future.)
SV * newSV_type_mortal(const svtype type)
"newSVuv"
Creates a new SV and copies an unsigned integer into it. The reference count for the
SV is set to 1.
SV * newSVuv(const UV u)
"Nullsv"
Null SV pointer. (No longer available when "PERL_CORE" is defined.)
"PL_sv_no"
This is the "false" SV. It is readonly. See "PL_sv_yes". Always refer to this as
&PL_sv_no.
SV PL_sv_no
"PL_sv_undef"
This is the "undef" SV. It is readonly. Always refer to this as &PL_sv_undef.
SV PL_sv_undef
"PL_sv_yes"
This is the "true" SV. It is readonly. See "PL_sv_no". Always refer to this as
&PL_sv_yes.
SV PL_sv_yes
"PL_sv_zero"
This readonly SV has a zero numeric value and a "0" string value. It's similar to
"PL_sv_no" except for its string value. Can be used as a cheap alternative to
mXPUSHi(0) for example. Always refer to this as &PL_sv_zero. Introduced in 5.28.
SV PL_sv_zero
"SAVE_DEFSV"
Localize $_. See "Localizing changes" in perlguts.
void SAVE_DEFSV
"sortsv"
In-place sort an array of SV pointers with the given comparison routine.
Currently this always uses mergesort. See "sortsv_flags" for a more flexible routine.
void sortsv(SV **array, size_t num_elts, SVCOMPARE_t cmp)
"sortsv_flags"
In-place sort an array of SV pointers with the given comparison routine, with various
SORTf_* flag options.
void sortsv_flags(SV **array, size_t num_elts, SVCOMPARE_t cmp,
U32 flags)
"SV"
Described in perlguts.
"SvAMAGIC"
Returns a boolean as to whether "sv" has overloading (active magic) enabled or not.
bool SvAMAGIC(SV * sv)
"SvAMAGIC_off"
Indicate that "sv" has overloading (active magic) disabled.
void SvAMAGIC_off(SV *sv)
"SvAMAGIC_on"
Indicate that "sv" has overloading (active magic) enabled.
void SvAMAGIC_on(SV *sv)
"sv_backoff"
Remove any string offset. You should normally use the "SvOOK_off" macro wrapper
instead.
void sv_backoff(SV * const sv)
"sv_bless"
Blesses an SV into a specified package. The SV must be an RV. The package must be
designated by its stash (see "gv_stashpv"). The reference count of the SV is
unaffected.
SV * sv_bless(SV * const sv, HV * const stash)
"SvBoolFlagsOK"
Returns a bool indicating whether the SV has the right flags set such that it is safe
to call BOOL_INTERNALS_sv_isbool() or BOOL_INTERNALS_sv_isbool_true() or
BOOL_INTERNALS_sv_isbool_false(). Currently equivalent to SvIandPOK(sv) or "SvIOK(sv)
&& SvPOK(sv)". Serialization may want to unroll this check. If so you are strongly
recommended to add code like "assert(SvBoolFlagsOK(sv));" before calling using any of
the BOOL_INTERNALS macros.
U32 SvBoolFlagsOK(SV* sv)
"sv_catpv"
"sv_catpv_flags"
"sv_catpv_mg"
"sv_catpv_nomg"
These concatenate the "NUL"-terminated string "sstr" onto the end of the string which
is in the SV. If the SV has the UTF-8 status set, then the bytes appended should be
valid UTF-8.
They differ only in how they handle magic:
"sv_catpv_mg" performs both 'get' and 'set' magic.
"sv_catpv" performs only 'get' magic.
"sv_catpv_nomg" skips all magic.
"sv_catpv_flags" has an extra "flags" parameter which allows you to specify any
combination of magic handling (using "SV_GMAGIC" and/or "SV_SMAGIC"), and to also
override the UTF-8 handling. By supplying the "SV_CATUTF8" flag, the appended string
is forced to be interpreted as UTF-8; by supplying instead the "SV_CATBYTES" flag, it
will be interpreted as just bytes. Either the SV or the string appended will be
upgraded to UTF-8 if necessary.
void sv_catpv (SV * const dsv, const char *sstr)
void sv_catpv_flags(SV *dsv, const char *sstr, const I32 flags)
void sv_catpv_mg (SV * const dsv, const char * const sstr)
void sv_catpv_nomg (SV * const dsv, const char *sstr)
"sv_catpvf"
"sv_catpvf_mg"
"sv_catpvf_mg_nocontext"
"sv_catpvf_nocontext"
These process their arguments like "sprintf", and append the formatted output to an
SV. As with "sv_vcatpvfn", argument reordering is not supporte when called with a
non-null C-style variable argument list.
If the appended data contains "wide" characters (including, but not limited to, SVs
with a UTF-8 PV formatted with %s, and characters >255 formatted with %c), the
original SV might get upgraded to UTF-8.
If the original SV was UTF-8, the pattern should be valid UTF-8; if the original SV
was bytes, the pattern should be too.
All perform 'get' magic, but only "sv_catpvf_mg" and "sv_catpvf_mg_nocontext" perform
'set' magic.
"sv_catpvf_nocontext" and "sv_catpvf_mg_nocontext" do not take a thread context
("aTHX") parameter, so are used in situations where the caller doesn't already have
the thread context.
NOTE: "sv_catpvf" must be explicitly called as "Perl_sv_catpvf" with an "aTHX_"
parameter.
NOTE: "sv_catpvf_mg" must be explicitly called as "Perl_sv_catpvf_mg" with an "aTHX_"
parameter.
void Perl_sv_catpvf (pTHX_ SV * const sv,
const char * const pat, ...)
void Perl_sv_catpvf_mg (pTHX_ SV * const sv,
const char * const pat, ...)
void sv_catpvf_mg_nocontext(SV * const sv,
const char * const pat, ...)
void sv_catpvf_nocontext (SV * const sv,
const char * const pat, ...)
"sv_catpvn"
"sv_catpvn_flags"
"sv_catpvn_mg"
"sv_catpvn_nomg"
These concatenate the "len" bytes of the string beginning at "ptr" onto the end of the
string which is in "dsv". The caller must make sure "ptr" contains at least "len"
bytes.
For all but "sv_catpvn_flags", the string appended is assumed to be valid UTF-8 if the
SV has the UTF-8 status set, and a string of bytes otherwise.
They differ in that:
"sv_catpvn_mg" performs both 'get' and 'set' magic on "dsv".
"sv_catpvn" performs only 'get' magic.
"sv_catpvn_nomg" skips all magic.
"sv_catpvn_flags" has an extra "flags" parameter which allows you to specify any
combination of magic handling (using "SV_GMAGIC" and/or "SV_SMAGIC") and to also
override the UTF-8 handling. By supplying the "SV_CATBYTES" flag, the appended string
is interpreted as plain bytes; by supplying instead the "SV_CATUTF8" flag, it will be
interpreted as UTF-8, and the "dsv" will be upgraded to UTF-8 if necessary.
"sv_catpvn", "sv_catpvn_mg", and "sv_catpvn_nomg" are implemented in terms of
"sv_catpvn_flags".
void sv_catpvn (SV *dsv, const char *sstr, STRLEN len)
void sv_catpvn_flags(SV * const dsv, const char *sstr,
const STRLEN len, const I32 flags)
void sv_catpvn_mg (SV *dsv, const char *sstr, STRLEN len)
void sv_catpvn_nomg (SV *dsv, const char *sstr, STRLEN len)
"sv_catpvs"
Like "sv_catpvn", but takes a literal string instead of a string/length pair.
void sv_catpvs(SV* sv, "literal string")
"sv_catpvs_flags"
Like "sv_catpvn_flags", but takes a literal string instead of a string/length pair.
void sv_catpvs_flags(SV* sv, "literal string", I32 flags)
"sv_catpvs_mg"
Like "sv_catpvn_mg", but takes a literal string instead of a string/length pair.
void sv_catpvs_mg(SV* sv, "literal string")
"sv_catpvs_nomg"
Like "sv_catpvn_nomg", but takes a literal string instead of a string/length pair.
void sv_catpvs_nomg(SV* sv, "literal string")
"sv_catsv"
"sv_catsv_flags"
"sv_catsv_mg"
"sv_catsv_nomg"
These concatenate the string from SV "sstr" onto the end of the string in SV "dsv".
If "sstr" is null, these are no-ops; otherwise only "dsv" is modified.
They differ only in what magic they perform:
"sv_catsv_mg" performs 'get' magic on both SVs before the copy, and 'set' magic on
"dsv" afterwards.
"sv_catsv" performs just 'get' magic, on both SVs.
"sv_catsv_nomg" skips all magic.
"sv_catsv_flags" has an extra "flags" parameter which allows you to use "SV_GMAGIC"
and/or "SV_SMAGIC" to specify any combination of magic handling (although either both
or neither SV will have 'get' magic applied to it.)
"sv_catsv", "sv_catsv_mg", and "sv_catsv_nomg" are implemented in terms of
"sv_catsv_flags".
void sv_catsv (SV *dsv, SV *sstr)
void sv_catsv_flags(SV * const dsv, SV * const sstr,
const I32 flags)
void sv_catsv_mg (SV *dsv, SV *sstr)
void sv_catsv_nomg (SV *dsv, SV *sstr)
"SV_CHECK_THINKFIRST"
Remove any encumbrances from "sv", that need to be taken care of before it is
modifiable. For example if it is Copy on Write (COW), now is the time to make that
copy.
If you know that you are about to change the PV value of "sv", instead use
""SV_CHECK_THINKFIRST_COW_DROP"" to avoid the write that would be immediately written
again.
void SV_CHECK_THINKFIRST(SV * sv)
"SV_CHECK_THINKFIRST_COW_DROP"
Call this when you are about to replace the PV value in "sv", which is potentially
copy-on-write. It stops any sharing with other SVs, so that no Copy on Write (COW)
actually happens. This COW would be useless, as it would immediately get changed to
something else. This function also removes any other encumbrances that would be
problematic when changing "sv".
void SV_CHECK_THINKFIRST_COW_DROP(SV * sv)
"sv_chop"
Efficient removal of characters from the beginning of the string buffer. SvPOK(sv),
or at least SvPOKp(sv), must be true and "ptr" must be a pointer to somewhere inside
the string buffer. "ptr" becomes the first character of the adjusted string. Uses
the "OOK" hack. On return, only SvPOK(sv) and SvPOKp(sv) among the "OK" flags will be
true.
Beware: after this function returns, "ptr" and SvPVX_const(sv) may no longer refer to
the same chunk of data.
The unfortunate similarity of this function's name to that of Perl's "chop" operator
is strictly coincidental. This function works from the left; "chop" works from the
right.
void sv_chop(SV * const sv, const char * const ptr)
"sv_clear"
Clear an SV: call any destructors, free up any memory used by the body, and free the
body itself. The SV's head is not freed, although its type is set to all 1's so that
it won't inadvertently be assumed to be live during global destruction etc. This
function should only be called when "REFCNT" is zero. Most of the time you'll want to
call "SvREFCNT_dec" instead.
void sv_clear(SV * const orig_sv)
"sv_cmp"
Compares the strings in two SVs. Returns -1, 0, or 1 indicating whether the string in
"sv1" is less than, equal to, or greater than the string in "sv2". Is UTF-8 and
'use bytes' aware, handles get magic, and will coerce its args to strings if
necessary. See also "sv_cmp_locale".
I32 sv_cmp(SV * const sv1, SV * const sv2)
"sv_cmp_flags"
Compares the strings in two SVs. Returns -1, 0, or 1 indicating whether the string in
"sv1" is less than, equal to, or greater than the string in "sv2". Is UTF-8 and
'use bytes' aware and will coerce its args to strings if necessary. If the flags has
the "SV_GMAGIC" bit set, it handles get magic. See also "sv_cmp_locale_flags".
I32 sv_cmp_flags(SV * const sv1, SV * const sv2, const U32 flags)
"sv_cmp_locale"
Compares the strings in two SVs in a locale-aware manner. Is UTF-8 and 'use bytes'
aware, handles get magic, and will coerce its args to strings if necessary. See also
"sv_cmp".
I32 sv_cmp_locale(SV * const sv1, SV * const sv2)
"sv_cmp_locale_flags"
Compares the strings in two SVs in a locale-aware manner. Is UTF-8 and 'use bytes'
aware and will coerce its args to strings if necessary. If the flags contain
"SV_GMAGIC", it handles get magic. See also "sv_cmp_flags".
I32 sv_cmp_locale_flags(SV * const sv1, SV * const sv2,
const U32 flags)
"sv_collxfrm"
This calls "sv_collxfrm_flags" with the SV_GMAGIC flag. See "sv_collxfrm_flags".
char * sv_collxfrm(SV * const sv, STRLEN * const nxp)
"sv_collxfrm_flags"
Add Collate Transform magic to an SV if it doesn't already have it. If the flags
contain "SV_GMAGIC", it handles get-magic.
Any scalar variable may carry "PERL_MAGIC_collxfrm" magic that contains the scalar
data of the variable, but transformed to such a format that a normal memory comparison
can be used to compare the data according to the locale settings.
char * sv_collxfrm_flags(SV * const sv, STRLEN * const nxp,
I32 const flags)
"sv_copypv"
"sv_copypv_flags"
"sv_copypv_nomg"
These copy a stringified representation of the source SV into the destination SV.
They automatically perform coercion of numeric values into strings. Guaranteed to
preserve the "UTF8" flag even from overloaded objects. Similar in nature to
"sv_2pv[_flags]" but they operate directly on an SV instead of just the string.
Mostly they use ""sv_2pv_flags"" to do the work, except when that would lose the
UTF-8'ness of the PV.
The three forms differ only in whether or not they perform 'get magic' on "sv".
"sv_copypv_nomg" skips 'get magic'; "sv_copypv" performs it; and "sv_copypv_flags"
either performs it (if the "SV_GMAGIC" bit is set in "flags") or doesn't (if that bit
is cleared).
void sv_copypv (SV * const dsv, SV * const ssv)
void sv_copypv_flags(SV * const dsv, SV * const ssv,
const I32 flags)
void sv_copypv_nomg (SV * const dsv, SV * const ssv)
"SvCUR"
Returns the length, in bytes, of the PV inside the SV. Note that this may not match
Perl's "length"; for that, use sv_len_utf8(sv). See "SvLEN" also.
STRLEN SvCUR(SV* sv)
"SvCUR_set"
Sets the current length, in bytes, of the C string which is in the SV. See "SvCUR"
and "SvIV_set">.
void SvCUR_set(SV* sv, STRLEN len)
"sv_2cv"
Using various gambits, try to get a CV from an SV; in addition, try if possible to set
*st and *gvp to the stash and GV associated with it. The flags in "lref" are passed
to "gv_fetchsv".
CV * sv_2cv(SV *sv, HV ** const st, GV ** const gvp,
const I32 lref)
"sv_dec"
"sv_dec_nomg"
These auto-decrement the value in the SV, doing string to numeric conversion if
necessary. They both handle operator overloading.
They differ only in that:
"sv_dec" handles 'get' magic; "sv_dec_nomg" skips 'get' magic.
void sv_dec(SV * const sv)
"sv_derived_from"
Exactly like "sv_derived_from_pv", but doesn't take a "flags" parameter.
bool sv_derived_from(SV *sv, const char * const name)
"sv_derived_from_hv"
Exactly like "sv_derived_from_pvn", but takes the name string as the "HvNAME" of the
given HV (which would presumably represent a stash).
bool sv_derived_from_hv(SV *sv, HV *hv)
"sv_derived_from_pv"
Exactly like "sv_derived_from_pvn", but takes a nul-terminated string instead of a
string/length pair.
bool sv_derived_from_pv(SV *sv, const char * const name,
U32 flags)
"sv_derived_from_pvn"
Returns a boolean indicating whether the SV is derived from the specified class at the
C level. To check derivation at the Perl level, call isa() as a normal Perl method.
Currently, the only significant value for "flags" is SVf_UTF8.
bool sv_derived_from_pvn(SV *sv, const char * const name,
const STRLEN len, U32 flags)
"sv_derived_from_sv"
Exactly like "sv_derived_from_pvn", but takes the name string in the form of an SV
instead of a string/length pair. This is the advised form.
bool sv_derived_from_sv(SV *sv, SV *namesv, U32 flags)
"sv_does"
Like "sv_does_pv", but doesn't take a "flags" parameter.
bool sv_does(SV *sv, const char * const name)
"sv_does_pv"
Like "sv_does_sv", but takes a nul-terminated string instead of an SV.
bool sv_does_pv(SV *sv, const char * const name, U32 flags)
"sv_does_pvn"
Like "sv_does_sv", but takes a string/length pair instead of an SV.
bool sv_does_pvn(SV *sv, const char * const name,
const STRLEN len, U32 flags)
"sv_does_sv"
Returns a boolean indicating whether the SV performs a specific, named role. The SV
can be a Perl object or the name of a Perl class.
bool sv_does_sv(SV *sv, SV *namesv, U32 flags)
"SvEND"
Returns a pointer to the spot just after the last character in the string which is in
the SV, where there is usually a trailing "NUL" character (even though Perl scalars do
not strictly require it). See "SvCUR". Access the character as "*(SvEND(sv))".
Warning: If "SvCUR" is equal to "SvLEN", then "SvEND" points to unallocated memory.
char* SvEND(SV* sv)
"sv_eq"
"sv_eq_flags"
These each return a boolean indicating whether or not the strings in the two SVs are
equal. If 'use bytes' is in effect, the comparison is byte-by-byte; otherwise
character-by-character. Each will coerce its args to strings if necessary.
They differ only in that "sv_eq" always processes get magic, while "sv_eq_flags"
processes get magic only when the "flags" parameter has the "SV_GMAGIC" bit set.
These functions do not handle operator overloading. For versions that do, see instead
"sv_streq" or "sv_streq_flags".
I32 sv_eq (SV *sv1, SV *sv2)
I32 sv_eq_flags(SV *sv1, SV *sv2, const U32 flags)
"sv_force_normal"
Undo various types of fakery on an SV: if the PV is a shared string, make a private
copy; if we're a ref, stop refing; if we're a glob, downgrade to an "xpvmg". See also
"sv_force_normal_flags".
void sv_force_normal(SV *sv)
"sv_force_normal_flags"
Undo various types of fakery on an SV, where fakery means "more than" a string: if the
PV is a shared string, make a private copy; if we're a ref, stop refing; if we're a
glob, downgrade to an "xpvmg"; if we're a copy-on-write scalar, this is the on-write
time when we do the copy, and is also used locally; if this is a vstring, drop the
vstring magic. If "SV_COW_DROP_PV" is set then a copy-on-write scalar drops its PV
buffer (if any) and becomes "SvPOK_off" rather than making a copy. (Used where this
scalar is about to be set to some other value.) In addition, the "flags" parameter
gets passed to sv_unref_flags() when unreffing. "sv_force_normal" calls this function
with flags set to 0.
This function is expected to be used to signal to perl that this SV is about to be
written to, and any extra book-keeping needs to be taken care of. Hence, it croaks on
read-only values.
void sv_force_normal_flags(SV * const sv, const U32 flags)
"sv_free"
Decrement an SV's reference count, and if it drops to zero, call "sv_clear" to invoke
destructors and free up any memory used by the body; finally, deallocating the SV's
head itself. Normally called via a wrapper macro "SvREFCNT_dec".
void sv_free(SV * const sv)
"SvGAMAGIC"
Returns true if the SV has get magic or overloading. If either is true then the
scalar is active data, and has the potential to return a new value every time it is
accessed. Hence you must be careful to only read it once per user logical operation
and work with that returned value. If neither is true then the scalar's value cannot
change unless written to.
U32 SvGAMAGIC(SV* sv)
"sv_get_backrefs"
NOTE: "sv_get_backrefs" is experimental and may change or be removed without notice.
If "sv" is the target of a weak reference then it returns the back references
structure associated with the sv; otherwise return "NULL".
When returning a non-null result the type of the return is relevant. If it is an AV
then the elements of the AV are the weak reference RVs which point at this item. If it
is any other type then the item itself is the weak reference.
See also Perl_sv_add_backref(), Perl_sv_del_backref(), Perl_sv_kill_backrefs()
SV * sv_get_backrefs(SV * const sv)
"SvGETMAGIC"
Invokes "mg_get" on an SV if it has 'get' magic. For example, this will call "FETCH"
on a tied variable. As of 5.37.1, this function is guaranteed to evaluate its
argument exactly once.
void SvGETMAGIC(SV *sv)
"sv_gets"
Get a line from the filehandle and store it into the SV, optionally appending to the
currently-stored string. If "append" is not 0, the line is appended to the SV instead
of overwriting it. "append" should be set to the byte offset that the appended string
should start at in the SV (typically, SvCUR(sv) is a suitable choice).
char * sv_gets(SV * const sv, PerlIO * const fp, I32 append)
"SvGROW"
Expands the character buffer in the SV so that it has room for the indicated number of
bytes (remember to reserve space for an extra trailing "NUL" character). Calls
"sv_grow" to perform the expansion if necessary. Returns a pointer to the character
buffer. SV must be of type >= "SVt_PV". One alternative is to call "sv_grow" if you
are not sure of the type of SV.
You might mistakenly think that "len" is the number of bytes to add to the existing
size, but instead it is the total size "sv" should be.
char * SvGROW(SV* sv, STRLEN len)
"SvIandPOK"
Returns a bool indicating whether the SV is both SvPOK() and SvIOK() at the same time.
Equivalent to "SvIOK(sv) && SvPOK(sv)" but more efficient.
U32 SvIandPOK(SV* sv)
"SvIandPOK_off"
Unsets the PV and IV status of an SV in one operation. Equivalent to "SvIOK_off(sv);
SvPK_off(v);" but more efficient.
void SvIandPOK_off(SV* sv)
"SvIandPOK_on"
Tells an SV that is a string and a number in one operation. Equivalent to
"SvIOK_on(sv); SvPOK_on(sv);" but more efficient.
void SvIandPOK_on(SV* sv)
"sv_inc"
"sv_inc_nomg"
These auto-increment the value in the SV, doing string to numeric conversion if
necessary. They both handle operator overloading.
They differ only in that "sv_inc" performs 'get' magic; "sv_inc_nomg" skips any magic.
void sv_inc(SV * const sv)
"sv_insert"
"sv_insert_flags"
These insert and/or replace a string at the specified offset/length within the SV.
Similar to the Perl substr() function, with "littlelen" bytes starting at "little"
replacing "len" bytes of the string in "bigstr" starting at "offset". They handle get
magic.
"sv_insert_flags" is identical to plain "sv_insert", but the extra "flags" are passed
to the "SvPV_force_flags" operation that is internally applied to "bigstr".
void sv_insert (SV * const bigstr, const STRLEN offset,
const STRLEN len, const char * const little,
const STRLEN littlelen)
void sv_insert_flags(SV * const bigstr, const STRLEN offset,
const STRLEN len, const char *little,
const STRLEN littlelen, const U32 flags)
"sv_2io"
Using various gambits, try to get an IO from an SV: the IO slot if its a GV; or the
recursive result if we're an RV; or the IO slot of the symbol named after the PV if
we're a string.
'Get' magic is ignored on the "sv" passed in, but will be called on SvRV(sv) if "sv"
is an RV.
IO * sv_2io(SV * const sv)
"SvIOK"
Returns a U32 value indicating whether the SV contains an integer.
U32 SvIOK(SV* sv)
"SvIOK_notUV"
Returns a boolean indicating whether the SV contains a signed integer.
bool SvIOK_notUV(SV* sv)
"SvIOK_off"
Unsets the IV status of an SV.
void SvIOK_off(SV* sv)
"SvIOK_on"
Tells an SV that it is an integer.
void SvIOK_on(SV* sv)
"SvIOK_only"
Tells an SV that it is an integer and disables all other "OK" bits.
void SvIOK_only(SV* sv)
"SvIOK_only_UV"
Tells an SV that it is an unsigned integer and disables all other "OK" bits.
void SvIOK_only_UV(SV* sv)
"SvIOKp"
Returns a U32 value indicating whether the SV contains an integer. Checks the private
setting. Use "SvIOK" instead.
U32 SvIOKp(SV* sv)
"SvIOK_UV"
Returns a boolean indicating whether the SV contains an integer that must be
interpreted as unsigned. A non-negative integer whose value is within the range of
both an IV and a UV may be flagged as either "SvUOK" or "SvIOK".
bool SvIOK_UV(SV* sv)
"sv_isa"
Returns a boolean indicating whether the SV is blessed into the specified class.
This does not check for subtypes or method overloading. Use "sv_isa_sv" to verify an
inheritance relationship in the same way as the "isa" operator by respecting any isa()
method overloading; or "sv_derived_from_sv" to test directly on the actual object
type.
int sv_isa(SV *sv, const char * const name)
"sv_isa_sv"
Returns a boolean indicating whether the SV is an object reference and is derived from
the specified class, respecting any isa() method overloading it may have. Returns
false if "sv" is not a reference to an object, or is not derived from the specified
class.
This is the function used to implement the behaviour of the "isa" operator.
Does not invoke magic on "sv".
Not to be confused with the older "sv_isa" function, which does not use an overloaded
isa() method, nor will check subclassing.
bool sv_isa_sv(SV *sv, SV *namesv)
"SvIsBOOL"
Returns true if the SV is one of the special boolean constants (PL_sv_yes or
PL_sv_no), or is a regular SV whose last assignment stored a copy of one.
bool SvIsBOOL(SV* sv)
"SvIsCOW"
Returns a U32 value indicating whether the SV is Copy-On-Write (either shared hash key
scalars, or full Copy On Write scalars if 5.9.0 is configured for COW).
U32 SvIsCOW(SV* sv)
"SvIsCOW_shared_hash"
Returns a boolean indicating whether the SV is Copy-On-Write shared hash key scalar.
bool SvIsCOW_shared_hash(SV* sv)
"sv_isobject"
Returns a boolean indicating whether the SV is an RV pointing to a blessed object. If
the SV is not an RV, or if the object is not blessed, then this will return false.
int sv_isobject(SV *sv)
"SvIV"
"SvIV_nomg"
"SvIVx"
These each coerce the given SV to IV and return it. The returned value in many
circumstances will get stored in "sv"'s IV slot, but not in all cases. (Use
"sv_setiv" to make sure it does).
As of 5.37.1, all are guaranteed to evaluate "sv" only once.
"SvIVx" is now identical to "SvIV", but prior to 5.37.1, it was the only form
guaranteed to evaluate "sv" only once.
"SvIV_nomg" is the same as "SvIV", but does not perform 'get' magic.
IV SvIV(SV *sv)
"sv_2iv_flags"
Return the integer value of an SV, doing any necessary string conversion. If "flags"
has the "SV_GMAGIC" bit set, does an mg_get() first. Normally used via the SvIV(sv)
and SvIVx(sv) macros.
IV sv_2iv_flags(SV * const sv, const I32 flags)
"SvIV_set"
Set the value of the IV pointer in sv to val. It is possible to perform the same
function of this macro with an lvalue assignment to "SvIVX". With future Perls,
however, it will be more efficient to use "SvIV_set" instead of the lvalue assignment
to "SvIVX".
void SvIV_set(SV* sv, IV val)
"SvIVX"
Returns the raw value in the SV's IV slot, without checks or conversions. Only use
when you are sure "SvIOK" is true. See also "SvIV".
IV SvIVX(SV* sv)
"SvLEN"
Returns the size of the string buffer in the SV, not including any part attributable
to "SvOOK". See "SvCUR".
STRLEN SvLEN(SV* sv)
"sv_len"
Returns the length of the string in the SV. Handles magic and type coercion and sets
the UTF8 flag appropriately. See also "SvCUR", which gives raw access to the
"xpv_cur" slot.
STRLEN sv_len(SV * const sv)
"SvLEN_set"
Set the size of the string buffer for the SV. See "SvLEN".
void SvLEN_set(SV* sv, STRLEN len)
"sv_len_utf8"
"sv_len_utf8_nomg"
These return the number of characters in the string in an SV, counting wide UTF-8
bytes as a single character. Both handle type coercion. They differ only in that
"sv_len_utf8" performs 'get' magic; "sv_len_utf8_nomg" skips any magic.
STRLEN sv_len_utf8(SV * const sv)
"SvLOCK"
Arranges for a mutual exclusion lock to be obtained on "sv" if a suitable module has
been loaded.
void SvLOCK(SV* sv)
"sv_magic"
Adds magic to an SV. First upgrades "sv" to type "SVt_PVMG" if necessary, then adds a
new magic item of type "how" to the head of the magic list.
See "sv_magicext" (which "sv_magic" now calls) for a description of the handling of
the "name" and "namlen" arguments.
You need to use "sv_magicext" to add magic to "SvREADONLY" SVs and also to add more
than one instance of the same "how".
void sv_magic(SV * const sv, SV * const obj, const int how,
const char * const name, const I32 namlen)
"sv_magicext"
Adds magic to an SV, upgrading it if necessary. Applies the supplied "vtable" and
returns a pointer to the magic added.
Note that "sv_magicext" will allow things that "sv_magic" will not. In particular,
you can add magic to "SvREADONLY" SVs, and add more than one instance of the same
"how".
If "namlen" is greater than zero then a "savepvn" copy of "name" is stored, if
"namlen" is zero then "name" is stored as-is and - as another special case - if "(name
&& namlen == HEf_SVKEY)" then "name" is assumed to contain an SV* and is stored as-is
with its "REFCNT" incremented.
(This is now used as a subroutine by "sv_magic".)
MAGIC * sv_magicext(SV * const sv, SV * const obj, const int how,
const MGVTBL * const vtbl,
const char * const name, const I32 namlen)
"SvMAGIC_set"
Set the value of the MAGIC pointer in "sv" to val. See "SvIV_set".
void SvMAGIC_set(SV* sv, MAGIC* val)
"sv_2mortal"
Marks an existing SV as mortal. The SV will be destroyed "soon", either by an
explicit call to "FREETMPS", or by an implicit call at places such as statement
boundaries. SvTEMP() is turned on which means that the SV's string buffer can be
"stolen" if this SV is copied. See also "sv_newmortal" and "sv_mortalcopy".
SV * sv_2mortal(SV * const sv)
"sv_mortalcopy"
Creates a new SV which is a copy of the original SV (using "sv_setsv"). The new SV is
marked as mortal. It will be destroyed "soon", either by an explicit call to
"FREETMPS", or by an implicit call at places such as statement boundaries. See also
"sv_newmortal" and "sv_2mortal".
SV * sv_mortalcopy(SV * const oldsv)
"sv_mortalcopy_flags"
Like "sv_mortalcopy", but the extra "flags" are passed to the "sv_setsv_flags".
SV * sv_mortalcopy_flags(SV * const oldsv, U32 flags)
"sv_newmortal"
Creates a new null SV which is mortal. The reference count of the SV is set to 1. It
will be destroyed "soon", either by an explicit call to "FREETMPS", or by an implicit
call at places such as statement boundaries. See also "sv_mortalcopy" and
"sv_2mortal".
SV * sv_newmortal()
"SvNIOK"
Returns a U32 value indicating whether the SV contains a number, integer or double.
U32 SvNIOK(SV* sv)
"SvNIOK_off"
Unsets the NV/IV status of an SV.
void SvNIOK_off(SV* sv)
"SvNIOKp"
Returns a U32 value indicating whether the SV contains a number, integer or double.
Checks the private setting. Use "SvNIOK" instead.
U32 SvNIOKp(SV* sv)
"SvNOK"
Returns a U32 value indicating whether the SV contains a double.
U32 SvNOK(SV* sv)
"SvNOK_off"
Unsets the NV status of an SV.
void SvNOK_off(SV* sv)
"SvNOK_on"
Tells an SV that it is a double.
void SvNOK_on(SV* sv)
"SvNOK_only"
Tells an SV that it is a double and disables all other OK bits.
void SvNOK_only(SV* sv)
"SvNOKp"
Returns a U32 value indicating whether the SV contains a double. Checks the private
setting. Use "SvNOK" instead.
U32 SvNOKp(SV* sv)
"sv_nolocking"
"DEPRECATED!" It is planned to remove "sv_nolocking" from a future release of Perl.
Do not use it for new code; remove it from existing code.
Dummy routine which "locks" an SV when there is no locking module present. Exists to
avoid test for a "NULL" function pointer and because it could potentially warn under
some level of strict-ness.
"Superseded" by sv_nosharing().
void sv_nolocking(SV *sv)
"sv_nounlocking"
"DEPRECATED!" It is planned to remove "sv_nounlocking" from a future release of Perl.
Do not use it for new code; remove it from existing code.
Dummy routine which "unlocks" an SV when there is no locking module present. Exists
to avoid test for a "NULL" function pointer and because it could potentially warn
under some level of strict-ness.
"Superseded" by sv_nosharing().
void sv_nounlocking(SV *sv)
"sv_numeq"
A convenient shortcut for calling "sv_numeq_flags" with the "SV_GMAGIC" flag. This
function basically behaves like the Perl code "$sv1 == $sv2".
bool sv_numeq(SV *sv1, SV *sv2)
"sv_numeq_flags"
Returns a boolean indicating whether the numbers in the two SVs are identical. If the
flags argument has the "SV_GMAGIC" bit set, it handles get-magic too. Will coerce its
args to numbers if necessary. Treats "NULL" as undef.
If flags does not have the "SV_SKIP_OVERLOAD" bit set, an attempt to use "=="
overloading will be made. If such overloading does not exist or the flag is set, then
regular numerical comparison will be used instead.
bool sv_numeq_flags(SV *sv1, SV *sv2, const U32 flags)
"SvNV"
"SvNV_nomg"
"SvNVx"
These each coerce the given SV to NV and return it. The returned value in many
circumstances will get stored in "sv"'s NV slot, but not in all cases. (Use
"sv_setnv" to make sure it does).
As of 5.37.1, all are guaranteed to evaluate "sv" only once.
"SvNVx" is now identical to "SvNV", but prior to 5.37.1, it was the only form
guaranteed to evaluate "sv" only once.
"SvNV_nomg" is the same as "SvNV", but does not perform 'get' magic.
NV SvNV(SV *sv)
"sv_2nv_flags"
Return the num value of an SV, doing any necessary string or integer conversion. If
"flags" has the "SV_GMAGIC" bit set, does an mg_get() first. Normally used via the
SvNV(sv) and SvNVx(sv) macros.
NV sv_2nv_flags(SV * const sv, const I32 flags)
"SvNV_set"
Set the value of the NV pointer in "sv" to val. See "SvIV_set".
void SvNV_set(SV* sv, NV val)
"SvNVX"
Returns the raw value in the SV's NV slot, without checks or conversions. Only use
when you are sure "SvNOK" is true. See also "SvNV".
NV SvNVX(SV* sv)
"SvOK"
Returns a U32 value indicating whether the value is defined. This is only meaningful
for scalars.
U32 SvOK(SV* sv)
"SvOOK"
Returns a U32 indicating whether the pointer to the string buffer is offset. This
hack is used internally to speed up removal of characters from the beginning of a
"SvPV". When "SvOOK" is true, then the start of the allocated string buffer is
actually SvOOK_offset() bytes before "SvPVX". This offset used to be stored in
"SvIVX", but is now stored within the spare part of the buffer.
U32 SvOOK(SV* sv)
"SvOOK_off"
Remove any string offset.
void SvOOK_off(SV * sv)
"SvOOK_offset"
Reads into "len" the offset from "SvPVX" back to the true start of the allocated
buffer, which will be non-zero if "sv_chop" has been used to efficiently remove
characters from start of the buffer. Implemented as a macro, which takes the address
of "len", which must be of type "STRLEN". Evaluates "sv" more than once. Sets "len"
to 0 if SvOOK(sv) is false.
void SvOOK_offset(SV*sv, STRLEN len)
"SvPOK"
Returns a U32 value indicating whether the SV contains a character string.
U32 SvPOK(SV* sv)
"SvPOK_off"
Unsets the PV status of an SV.
void SvPOK_off(SV* sv)
"SvPOK_on"
Tells an SV that it is a string.
void SvPOK_on(SV* sv)
"SvPOK_only"
Tells an SV that it is a string and disables all other "OK" bits. Will also turn off
the UTF-8 status.
void SvPOK_only(SV* sv)
"SvPOK_only_UTF8"
Tells an SV that it is a string and disables all other "OK" bits, and leaves the UTF-8
status as it was.
void SvPOK_only_UTF8(SV* sv)
"SvPOKp"
Returns a U32 value indicating whether the SV contains a character string. Checks the
private setting. Use "SvPOK" instead.
U32 SvPOKp(SV* sv)
"sv_pos_b2u"
Converts the value pointed to by "offsetp" from a count of bytes from the start of the
string, to a count of the equivalent number of UTF-8 chars. Handles magic and type
coercion.
Use "sv_pos_b2u_flags" in preference, which correctly handles strings longer than 2Gb.
void sv_pos_b2u(SV * const sv, I32 * const offsetp)
"sv_pos_b2u_flags"
Converts "offset" from a count of bytes from the start of the string, to a count of
the equivalent number of UTF-8 chars. Handles type coercion. "flags" is passed to
"SvPV_flags", and usually should be "SV_GMAGIC|SV_CONST_RETURN" to handle magic.
STRLEN sv_pos_b2u_flags(SV * const sv, STRLEN const offset,
U32 flags)
"sv_pos_u2b"
Converts the value pointed to by "offsetp" from a count of UTF-8 chars from the start
of the string, to a count of the equivalent number of bytes; if "lenp" is non-zero, it
does the same to "lenp", but this time starting from the offset, rather than from the
start of the string. Handles magic and type coercion.
Use "sv_pos_u2b_flags" in preference, which correctly handles strings longer than 2Gb.
void sv_pos_u2b(SV * const sv, I32 * const offsetp,
I32 * const lenp)
"sv_pos_u2b_flags"
Converts the offset from a count of UTF-8 chars from the start of the string, to a
count of the equivalent number of bytes; if "lenp" is non-zero, it does the same to
"lenp", but this time starting from "offset", rather than from the start of the
string. Handles type coercion. "flags" is passed to "SvPV_flags", and usually should
be "SV_GMAGIC|SV_CONST_RETURN" to handle magic.
STRLEN sv_pos_u2b_flags(SV * const sv, STRLEN uoffset,
STRLEN * const lenp, U32 flags)
"SvPV"
"SvPV_const"
"SvPV_flags"
"SvPV_flags_const"
"SvPV_flags_mutable"
"SvPV_mutable"
"SvPV_nolen"
"SvPV_nolen_const"
"SvPV_nomg"
"SvPV_nomg_const"
"SvPV_nomg_const_nolen"
"SvPV_nomg_nolen"
"SvPVbyte"
"SvPVbyte_nolen"
"SvPVbyte_nomg"
"SvPVbyte_or_null"
"SvPVbyte_or_null_nomg"
"SvPVbytex"
"SvPVbytex_nolen"
"SvPVutf8"
"SvPVutf8_nolen"
"SvPVutf8_nomg"
"SvPVutf8_or_null"
"SvPVutf8_or_null_nomg"
"SvPVutf8x"
"SvPVx"
"SvPVx_const"
"SvPVx_nolen"
"SvPVx_nolen_const"
These each return a pointer to the string in "sv", or a stringified form of "sv" if it
does not contain a string. The SV may cache the stringified version becoming "SvPOK".
This is a very basic and common operation, so there are lots of slightly different
versions of it.
Note that there is no guarantee that the return value of SvPV(sv), for example, is
equal to SvPVX(sv), or that SvPVX(sv) contains valid data, or that successive calls to
SvPV(sv) (or another of these forms) will return the same pointer value each time.
This is due to the way that things like overloading and Copy-On-Write are handled. In
these cases, the return value may point to a temporary buffer or similar. If you
absolutely need the "SvPVX" field to be valid (for example, if you intend to write to
it), then see "SvPV_force".
The differences between the forms are:
The forms with neither "byte" nor "utf8" in their names (e.g., "SvPV" or "SvPV_nolen")
can expose the SV's internal string buffer. If that buffer consists entirely of bytes
0-255 and includes any bytes above 127, then you MUST consult "SvUTF8" to determine
the actual code points the string is meant to contain. Generally speaking, it is
probably safer to prefer "SvPVbyte", "SvPVutf8", and the like. See "How do I pass a
Perl string to a C library?" in perlguts for more details.
The forms with "flags" in their names allow you to use the "flags" parameter to
specify to process 'get' magic (by setting the "SV_GMAGIC" flag) or to skip 'get'
magic (by clearing it). The other forms process 'get' magic, except for the ones with
"nomg" in their names, which skip 'get' magic.
The forms that take a "len" parameter will set that variable to the byte length of the
resultant string (these are macros, so don't use &len).
The forms with "nolen" in their names indicate they don't have a "len" parameter.
They should be used only when it is known that the PV is a C string, terminated by a
NUL byte, and without intermediate NUL characters; or when you don't care about its
length.
The forms with "const" in their names return "const char *" so that the compiler will
hopefully complain if you were to try to modify the contents of the string (unless you
cast away const yourself).
The other forms return a mutable pointer so that the string is modifiable by the
caller; this is emphasized for the ones with "mutable" in their names.
As of 5.38, all forms are guaranteed to evaluate "sv" exactly once. For earlier
Perls, use a form whose name ends with "x" for single evaluation.
"SvPVutf8" is like "SvPV", but converts "sv" to UTF-8 first if not already UTF-8.
Similarly, the other forms with "utf8" in their names correspond to their respective
forms without.
"SvPVutf8_or_null" and "SvPVutf8_or_null_nomg" don't have corresponding non-"utf8"
forms. Instead they are like "SvPVutf8_nomg", but when "sv" is undef, they return
"NULL".
"SvPVbyte" is like "SvPV", but converts "sv" to byte representation first if currently
encoded as UTF-8. If "sv" cannot be downgraded from UTF-8, it croaks. Similarly, the
other forms with "byte" in their names correspond to their respective forms without.
"SvPVbyte_or_null" doesn't have a corresponding non-"byte" form. Instead it is like
"SvPVbyte", but when "sv" is undef, it returns "NULL".
char* SvPV (SV* sv, STRLEN len)
const char* SvPV_const (SV* sv, STRLEN len)
char* SvPV_flags (SV* sv, STRLEN len, U32 flags)
const char* SvPV_flags_const (SV* sv, STRLEN len, U32 flags)
char* SvPV_flags_mutable (SV* sv, STRLEN len, U32 flags)
char* SvPV_mutable (SV* sv, STRLEN len)
char* SvPV_nolen (SV* sv)
const char* SvPV_nolen_const (SV* sv)
char* SvPV_nomg (SV* sv, STRLEN len)
const char* SvPV_nomg_const (SV* sv, STRLEN len)
const char* SvPV_nomg_const_nolen(SV* sv)
char* SvPV_nomg_nolen (SV* sv)
char* SvPVbyte (SV* sv, STRLEN len)
char* SvPVbyte_nolen (SV* sv)
char* SvPVbyte_nomg (SV* sv, STRLEN len)
char* SvPVbyte_or_null (SV* sv, STRLEN len)
char* SvPVbyte_or_null_nomg(SV* sv, STRLEN len)
char* SvPVbytex (SV* sv, STRLEN len)
char* SvPVbytex_nolen (SV* sv)
char* SvPVutf8 (SV* sv, STRLEN len)
char* SvPVutf8_nolen (SV* sv)
char* SvPVutf8_nomg (SV* sv, STRLEN len)
char* SvPVutf8_or_null (SV* sv, STRLEN len)
char* SvPVutf8_or_null_nomg(SV* sv, STRLEN len)
char* SvPVutf8x (SV* sv, STRLEN len)
char* SvPVx (SV* sv, STRLEN len)
const char* SvPVx_const (SV* sv, STRLEN len)
char* SvPVx_nolen (SV* sv)
const char* SvPVx_nolen_const (SV* sv)
"sv_2pv"
"sv_2pv_flags"
These implement the various forms of the ""SvPV"" in perlapi macros. The macros are
the preferred interface.
These return a pointer to the string value of an SV (coercing it to a string if
necessary), and set *lp to its length in bytes.
The forms differ in that plain "sv_2pvbyte" always processes 'get' magic; and
"sv_2pvbyte_flags" processes 'get' magic if and only if "flags" contains "SV_GMAGIC".
char * sv_2pv (SV *sv, STRLEN *lp)
char * sv_2pv_flags(SV * const sv, STRLEN * const lp,
const U32 flags)
"sv_2pvbyte"
"sv_2pvbyte_flags"
These implement the various forms of the ""SvPVbyte"" in perlapi macros. The macros
are the preferred interface.
These return a pointer to the byte-encoded representation of the SV, and set *lp to
its length. If the SV is marked as being encoded as UTF-8, it will be downgraded, if
possible, to a byte string. If the SV cannot be downgraded, they croak.
The forms differ in that plain "sv_2pvbyte" always processes 'get' magic; and
"sv_2pvbyte_flags" processes 'get' magic if and only if "flags" contains "SV_GMAGIC".
char * sv_2pvbyte (SV *sv, STRLEN * const lp)
char * sv_2pvbyte_flags(SV *sv, STRLEN * const lp,
const U32 flags)
"SvPVCLEAR"
Ensures that sv is a SVt_PV and that its SvCUR is 0, and that it is properly null
terminated. Equivalent to sv_setpvs(""), but more efficient.
char * SvPVCLEAR(SV* sv)
"SvPVCLEAR_FRESH"
Like SvPVCLEAR, but optimized for newly-minted SVt_PV/PVIV/PVNV/PVMG that already have
a PV buffer allocated, but no SvTHINKFIRST.
char * SvPVCLEAR_FRESH(SV* sv)
"SvPV_force"
"SvPV_force_flags"
"SvPV_force_flags_mutable"
"SvPV_force_flags_nolen"
"SvPV_force_mutable"
"SvPV_force_nolen"
"SvPV_force_nomg"
"SvPV_force_nomg_nolen"
"SvPVbyte_force"
"SvPVbytex_force"
"SvPVutf8_force"
"SvPVutf8x_force"
"SvPVx_force"
These are like "SvPV", returning the string in the SV, but will force the SV into
containing a string ("SvPOK"), and only a string ("SvPOK_only"), by hook or by crook.
You need to use one of these "force" routines if you are going to update the "SvPVX"
directly.
Note that coercing an arbitrary scalar into a plain PV will potentially strip useful
data from it. For example if the SV was "SvROK", then the referent will have its
reference count decremented, and the SV itself may be converted to an "SvPOK" scalar
with a string buffer containing a value such as "ARRAY(0x1234)".
The differences between the forms are:
The forms with "flags" in their names allow you to use the "flags" parameter to
specify to perform 'get' magic (by setting the "SV_GMAGIC" flag) or to skip 'get'
magic (by clearing it). The other forms do perform 'get' magic, except for the ones
with "nomg" in their names, which skip 'get' magic.
The forms that take a "len" parameter will set that variable to the byte length of the
resultant string (these are macros, so don't use &len).
The forms with "nolen" in their names indicate they don't have a "len" parameter.
They should be used only when it is known that the PV is a C string, terminated by a
NUL byte, and without intermediate NUL characters; or when you don't care about its
length.
The forms with "mutable" in their names are effectively the same as those without, but
the name emphasizes that the string is modifiable by the caller, which it is in all
the forms.
"SvPVutf8_force" is like "SvPV_force", but converts "sv" to UTF-8 first if not already
UTF-8.
"SvPVutf8x_force" is like "SvPVutf8_force", but guarantees to evaluate "sv" only once;
use the more efficient "SvPVutf8_force" otherwise.
"SvPVbyte_force" is like "SvPV_force", but converts "sv" to byte representation first
if currently encoded as UTF-8. If the SV cannot be downgraded from UTF-8, this
croaks.
"SvPVbytex_force" is like "SvPVbyte_force", but guarantees to evaluate "sv" only once;
use the more efficient "SvPVbyte_force" otherwise.
char* SvPV_force (SV* sv, STRLEN len)
char* SvPV_force_flags (SV * sv, STRLEN len, U32 flags)
char* SvPV_force_flags_mutable(SV * sv, STRLEN len, U32 flags)
char* SvPV_force_flags_nolen (SV * sv, U32 flags)
char* SvPV_force_mutable (SV * sv, STRLEN len)
char* SvPV_force_nolen (SV* sv)
char* SvPV_force_nomg (SV* sv, STRLEN len)
char* SvPV_force_nomg_nolen (SV * sv)
char* SvPVbyte_force (SV * sv, STRLEN len)
char* SvPVbytex_force (SV * sv, STRLEN len)
char* SvPVutf8_force (SV * sv, STRLEN len)
char* SvPVutf8x_force (SV * sv, STRLEN len)
char* SvPVx_force (SV* sv, STRLEN len)
"SvPV_free"
Frees the PV buffer in "sv", leaving things in a precarious state, so should only be
used as part of a larger operation
void SvPV_free(SV * sv)
"sv_pvn_force_flags"
Get a sensible string out of the SV somehow. If "flags" has the "SV_GMAGIC" bit set,
will "mg_get" on "sv" if appropriate, else not. "sv_pvn_force" and
"sv_pvn_force_nomg" are implemented in terms of this function. You normally want to
use the various wrapper macros instead: see "SvPV_force" and "SvPV_force_nomg".
char * sv_pvn_force_flags(SV * const sv, STRLEN * const lp,
const U32 flags)
"SvPV_renew"
Low level micro optimization of "SvGROW". It is generally better to use "SvGROW"
instead. This is because "SvPV_renew" ignores potential issues that "SvGROW" handles.
"sv" needs to have a real "PV" that is unencumbered by things like COW. Using
"SV_CHECK_THINKFIRST" or "SV_CHECK_THINKFIRST_COW_DROP" before calling this should
clean it up, but why not just use "SvGROW" if you're not sure about the provenance?
void SvPV_renew(SV* sv, STRLEN len)
"SvPV_set"
This is probably not what you want to use, you probably wanted "sv_usepvn_flags" or
"sv_setpvn" or "sv_setpvs".
Set the value of the PV pointer in "sv" to the Perl allocated "NUL"-terminated string
"val". See also "SvIV_set".
Remember to free the previous PV buffer. There are many things to check. Beware that
the existing pointer may be involved in copy-on-write or other mischief, so do
SvOOK_off(sv) and use "sv_force_normal" or "SvPV_force" (or check the "SvIsCOW" flag)
first to make sure this modification is safe. Then finally, if it is not a COW, call
"SvPV_free" to free the previous PV buffer.
void SvPV_set(SV* sv, char* val)
"SvPV_shrink_to_cur"
Trim any trailing unused memory in the PV of "sv", which needs to have a real "PV"
that is unencumbered by things like COW. Think first before using this functionality.
Is the space saving really worth giving up COW? Will the needed size of "sv" stay the
same?
If the answers are both yes, then use ""SV_CHECK_THINKFIRST"" or
""SV_CHECK_THINKFIRST_COW_DROP"" before calling this.
void SvPV_shrink_to_cur(SV* sv)
"sv_2pvutf8"
"sv_2pvutf8_flags"
These implement the various forms of the ""SvPVutf8"" in perlapi macros. The macros
are the preferred interface.
These return a pointer to the UTF-8-encoded representation of the SV, and set *lp to
its length in bytes. They may cause the SV to be upgraded to UTF-8 as a side-effect.
The forms differ in that plain "sv_2pvutf8" always processes 'get' magic; and
"sv_2pvutf8_flags" processes 'get' magic if and only if "flags" contains "SV_GMAGIC".
char * sv_2pvutf8 (SV *sv, STRLEN * const lp)
char * sv_2pvutf8_flags(SV *sv, STRLEN * const lp,
const U32 flags)
"SvPVX"
"SvPVX_const"
"SvPVX_mutable"
"SvPVXx"
These return a pointer to the physical string in the SV. The SV must contain a
string. Prior to 5.9.3 it is not safe to execute these unless the SV's type >=
"SVt_PV".
These are also used to store the name of an autoloaded subroutine in an XS AUTOLOAD
routine. See "Autoloading with XSUBs" in perlguts.
"SvPVXx" is identical to "SvPVX".
"SvPVX_mutable" is merely a synonym for "SvPVX", but its name emphasizes that the
string is modifiable by the caller.
"SvPVX_const" differs in that the return value has been cast so that the compiler will
complain if you were to try to modify the contents of the string, (unless you cast
away const yourself).
char* SvPVX (SV* sv)
const char* SvPVX_const (SV* sv)
char* SvPVX_mutable(SV* sv)
char* SvPVXx (SV* sv)
"SvPVXtrue"
Returns a boolean as to whether or not "sv" contains a PV that is considered TRUE.
FALSE is returned if "sv" doesn't contain a PV, or if the PV it does contain is zero
length, or consists of just the single character '0'. Every other PV value is
considered TRUE.
As of Perl v5.37.1, "sv" is evaluated exactly once; in earlier releases, it could be
evaluated more than once.
bool SvPVXtrue(SV *sv)
"SvREADONLY"
Returns true if the argument is readonly, otherwise returns false. Exposed to perl
code via Internals::SvREADONLY().
U32 SvREADONLY(SV* sv)
"SvREADONLY_off"
Mark an object as not-readonly. Exactly what this mean depends on the object type.
Exposed to perl code via Internals::SvREADONLY().
U32 SvREADONLY_off(SV* sv)
"SvREADONLY_on"
Mark an object as readonly. Exactly what this means depends on the object type.
Exposed to perl code via Internals::SvREADONLY().
U32 SvREADONLY_on(SV* sv)
"sv_ref"
Returns a SV describing what the SV passed in is a reference to.
dst can be a SV to be set to the description or NULL, in which case a mortal SV is
returned.
If ob is true and the SV is blessed, the description is the class name, otherwise it
is the type of the SV, "SCALAR", "ARRAY" etc.
SV * sv_ref(SV *dst, const SV * const sv, const int ob)
"SvREFCNT"
Returns the value of the object's reference count. Exposed to perl code via
Internals::SvREFCNT().
U32 SvREFCNT(SV* sv)
"SvREFCNT_dec"
"SvREFCNT_dec_set_NULL"
"SvREFCNT_dec_ret_NULL"
"SvREFCNT_dec_NN"
These decrement the reference count of the given SV.
"SvREFCNT_dec_NN" may only be used when "sv" is known to not be "NULL".
The function SvREFCNT_dec_ret_NULL() is identical to the SvREFCNT_dec() except it
returns a NULL "SV *". It is used by SvREFCNT_dec_set_NULL() which is a macro which
will, when passed a non-NULL argument, decrement the reference count of its argument
and then set it to NULL. You can replace code of the following form:
if (sv) {
SvREFCNT_dec_NN(sv);
sv = NULL;
}
with
SvREFCNT_dec_set_NULL(sv);
void SvREFCNT_dec (SV *sv)
void SvREFCNT_dec_set_NULL(SV *sv)
SV * SvREFCNT_dec_ret_NULL(SV *sv)
void SvREFCNT_dec_NN (SV *sv)
"SvREFCNT_inc"
"SvREFCNT_inc_NN"
"SvREFCNT_inc_simple"
"SvREFCNT_inc_simple_NN"
"SvREFCNT_inc_simple_void"
"SvREFCNT_inc_simple_void_NN"
"SvREFCNT_inc_void"
"SvREFCNT_inc_void_NN"
These all increment the reference count of the given SV. The ones without "void" in
their names return the SV.
"SvREFCNT_inc" is the base operation; the rest are optimizations if various input
constraints are known to be true; hence, all can be replaced with "SvREFCNT_inc".
"SvREFCNT_inc_NN" can only be used if you know "sv" is not "NULL". Since we don't
have to check the NULLness, it's faster and smaller.
"SvREFCNT_inc_void" can only be used if you don't need the return value. The macro
doesn't need to return a meaningful value.
"SvREFCNT_inc_void_NN" can only be used if you both don't need the return value, and
you know that "sv" is not "NULL". The macro doesn't need to return a meaningful
value, or check for NULLness, so it's smaller and faster.
"SvREFCNT_inc_simple" can only be used with expressions without side effects. Since
we don't have to store a temporary value, it's faster.
"SvREFCNT_inc_simple_NN" can only be used with expressions without side effects and
you know "sv" is not "NULL". Since we don't have to store a temporary value, nor
check for NULLness, it's faster and smaller.
"SvREFCNT_inc_simple_void" can only be used with expressions without side effects and
you don't need the return value.
"SvREFCNT_inc_simple_void_NN" can only be used with expressions without side effects,
you don't need the return value, and you know "sv" is not "NULL".
SV * SvREFCNT_inc (SV *sv)
SV * SvREFCNT_inc_NN (SV *sv)
SV* SvREFCNT_inc_simple (SV* sv)
SV* SvREFCNT_inc_simple_NN (SV* sv)
void SvREFCNT_inc_simple_void (SV* sv)
void SvREFCNT_inc_simple_void_NN(SV* sv)
void SvREFCNT_inc_void (SV *sv)
void SvREFCNT_inc_void_NN (SV* sv)
"sv_reftype"
Returns a string describing what the SV is a reference to.
If ob is true and the SV is blessed, the string is the class name, otherwise it is the
type of the SV, "SCALAR", "ARRAY" etc.
const char * sv_reftype(const SV * const sv, const int ob)
"sv_replace"
Make the first argument a copy of the second, then delete the original. The target SV
physically takes over ownership of the body of the source SV and inherits its flags;
however, the target keeps any magic it owns, and any magic in the source is discarded.
Note that this is a rather specialist SV copying operation; most of the time you'll
want to use "sv_setsv" or one of its many macro front-ends.
void sv_replace(SV * const sv, SV * const nsv)
"sv_report_used"
Dump the contents of all SVs not yet freed (debugging aid).
void sv_report_used()
"sv_reset"
Underlying implementation for the "reset" Perl function. Note that the perl-level
function is vaguely deprecated.
void sv_reset(const char *s, HV * const stash)
"SvROK"
Tests if the SV is an RV.
U32 SvROK(SV* sv)
"SvROK_off"
Unsets the RV status of an SV.
void SvROK_off(SV* sv)
"SvROK_on"
Tells an SV that it is an RV.
void SvROK_on(SV* sv)
"SvRV"
Dereferences an RV to return the SV.
SV* SvRV(SV* sv)
"SvRV_set"
Set the value of the RV pointer in "sv" to val. See "SvIV_set".
void SvRV_set(SV* sv, SV* val)
"sv_rvunweaken"
Unweaken a reference: Clear the "SvWEAKREF" flag on this RV; remove the backreference
to this RV from the array of backreferences associated with the target SV, increment
the refcount of the target. Silently ignores "undef" and warns on non-weak
references.
SV * sv_rvunweaken(SV * const sv)
"sv_rvweaken"
Weaken a reference: set the "SvWEAKREF" flag on this RV; give the referred-to SV
"PERL_MAGIC_backref" magic if it hasn't already; and push a back-reference to this RV
onto the array of backreferences associated with that magic. If the RV is magical,
set magic will be called after the RV is cleared. Silently ignores "undef" and warns
on already-weak references.
SV * sv_rvweaken(SV * const sv)
"sv_setbool"
"sv_setbool_mg"
These set an SV to a true or false boolean value, upgrading first if necessary.
They differ only in that "sv_setbool_mg" handles 'set' magic; "sv_setbool" does not.
void sv_setbool(SV *sv, bool b)
"sv_set_bool"
Equivalent to "sv_setsv(sv, bool_val ? &Pl_sv_yes : &PL_sv_no)", but may be made more
efficient in the future. Doesn't handle set magic.
The perl equivalent is "$sv = !!$expr;".
Introduced in perl 5.35.11.
void sv_set_bool(SV *sv, const bool bool_val)
"sv_set_false"
Equivalent to "sv_setsv(sv, &PL_sv_no)", but may be made more efficient in the future.
Doesn't handle set magic.
The perl equivalent is "$sv = !1;".
Introduced in perl 5.35.11.
void sv_set_false(SV *sv)
"sv_setiv"
"sv_setiv_mg"
These copy an integer into the given SV, upgrading first if necessary.
They differ only in that "sv_setiv_mg" handles 'set' magic; "sv_setiv" does not.
void sv_setiv (SV * const sv, const IV num)
void sv_setiv_mg(SV * const sv, const IV i)
"SvSETMAGIC"
Invokes "mg_set" on an SV if it has 'set' magic. This is necessary after modifying a
scalar, in case it is a magical variable like $| or a tied variable (it calls
"STORE"). This macro evaluates its argument more than once.
void SvSETMAGIC(SV* sv)
"SvSetMagicSV"
"SvSetMagicSV_nosteal"
"SvSetSV"
"SvSetSV_nosteal"
if "dsv" is the same as "ssv", these do nothing. Otherwise they all call some form of
"sv_setsv". They may evaluate their arguments more than once.
The only differences are:
"SvSetMagicSV" and "SvSetMagicSV_nosteal" perform any required 'set' magic afterwards
on the destination SV; "SvSetSV" and "SvSetSV_nosteal" do not.
"SvSetSV_nosteal" "SvSetMagicSV_nosteal" call a non-destructive version of "sv_setsv".
void SvSetMagicSV(SV* dsv, SV* ssv)
"sv_setnv"
"sv_setnv_mg"
These copy a double into the given SV, upgrading first if necessary.
They differ only in that "sv_setnv_mg" handles 'set' magic; "sv_setnv" does not.
void sv_setnv(SV * const sv, const NV num)
"sv_setpv"
"sv_setpv_mg"
"sv_setpvn"
"sv_setpvn_fresh"
"sv_setpvn_mg"
"sv_setpvs"
"sv_setpvs_mg"
These copy a string into the SV "sv", making sure it is "SvPOK_only".
In the "pvs" forms, the string must be a C literal string, enclosed in double quotes.
In the "pvn" forms, the first byte of the string is pointed to by "ptr", and "len"
indicates the number of bytes to be copied, potentially including embedded "NUL"
characters.
In the plain "pv" forms, "ptr" points to a NUL-terminated C string. That is, it
points to the first byte of the string, and the copy proceeds up through the first
encountered "NUL" byte.
In the forms that take a "ptr" argument, if it is NULL, the SV will become undefined.
The UTF-8 flag is not changed by these functions.
A terminating NUL byte is guaranteed in the result.
The "_mg" forms handle 'set' magic; the other forms skip all magic.
"sv_setpvn_fresh" is a cut-down alternative to "sv_setpvn", intended ONLY to be used
with a fresh sv that has been upgraded to a SVt_PV, SVt_PVIV, SVt_PVNV, or SVt_PVMG.
void sv_setpv (SV * const sv, const char * const ptr)
void sv_setpv_mg (SV * const sv, const char * const ptr)
void sv_setpvn (SV * const sv, const char * const ptr,
const STRLEN len)
void sv_setpvn_fresh(SV * const sv, const char * const ptr,
const STRLEN len)
void sv_setpvn_mg (SV * const sv, const char * const ptr,
const STRLEN len)
void sv_setpvs (SV* sv, "literal string")
void sv_setpvs_mg (SV* sv, "literal string")
"sv_setpv_bufsize"
Sets the SV to be a string of "cur" bytes length, with at least "len" bytes available.
Ensures that there is a null byte at "SvEND".
Returns a char * pointer to the SvPV buffer.
The caller must set the first "cur" bytes of "sv" before the first use of its
contents. This means that if "cur" is zero, the SV is immediately fully formed and
ready to use, just like any other SV containing an empty string.
char * sv_setpv_bufsize(SV * const sv, const STRLEN cur,
const STRLEN len)
"sv_setpvf"
"sv_setpvf_mg"
"sv_setpvf_mg_nocontext"
"sv_setpvf_nocontext"
These work like "sv_catpvf" but copy the text into the SV instead of appending it.
The differences between these are:
"sv_setpvf_mg" and "sv_setpvf_mg_nocontext" perform 'set' magic; "sv_setpvf" and
"sv_setpvf_nocontext" skip all magic.
"sv_setpvf_nocontext" and "sv_setpvf_mg_nocontext" do not take a thread context
("aTHX") parameter, so are used in situations where the caller doesn't already have
the thread context.
The UTF-8 flag is not changed by these functions.
NOTE: "sv_setpvf" must be explicitly called as "Perl_sv_setpvf" with an "aTHX_"
parameter.
NOTE: "sv_setpvf_mg" must be explicitly called as "Perl_sv_setpvf_mg" with an "aTHX_"
parameter.
void Perl_sv_setpvf (pTHX_ SV * const sv,
const char * const pat, ...)
void Perl_sv_setpvf_mg (pTHX_ SV * const sv,
const char * const pat, ...)
void sv_setpvf_mg_nocontext(SV * const sv,
const char * const pat, ...)
void sv_setpvf_nocontext (SV * const sv,
const char * const pat, ...)
"sv_setref_iv"
Copies an integer into a new SV, optionally blessing the SV. The "rv" argument will
be upgraded to an RV. That RV will be modified to point to the new SV. The
"classname" argument indicates the package for the blessing. Set "classname" to
"NULL" to avoid the blessing. The new SV will have a reference count of 1, and the RV
will be returned.
SV * sv_setref_iv(SV * const rv, const char * const classname,
const IV iv)
"sv_setref_nv"
Copies a double into a new SV, optionally blessing the SV. The "rv" argument will be
upgraded to an RV. That RV will be modified to point to the new SV. The "classname"
argument indicates the package for the blessing. Set "classname" to "NULL" to avoid
the blessing. The new SV will have a reference count of 1, and the RV will be
returned.
SV * sv_setref_nv(SV * const rv, const char * const classname,
const NV nv)
"sv_setref_pv"
Copies a pointer into a new SV, optionally blessing the SV. The "rv" argument will be
upgraded to an RV. That RV will be modified to point to the new SV. If the "pv"
argument is "NULL", then "PL_sv_undef" will be placed into the SV. The "classname"
argument indicates the package for the blessing. Set "classname" to "NULL" to avoid
the blessing. The new SV will have a reference count of 1, and the RV will be
returned.
Do not use with other Perl types such as HV, AV, SV, CV, because those objects will
become corrupted by the pointer copy process.
Note that "sv_setref_pvn" copies the string while this copies the pointer.
SV * sv_setref_pv(SV * const rv, const char * const classname,
void * const pv)
"sv_setref_pvn"
Copies a string into a new SV, optionally blessing the SV. The length of the string
must be specified with "n". The "rv" argument will be upgraded to an RV. That RV
will be modified to point to the new SV. The "classname" argument indicates the
package for the blessing. Set "classname" to "NULL" to avoid the blessing. The new
SV will have a reference count of 1, and the RV will be returned.
Note that "sv_setref_pv" copies the pointer while this copies the string.
SV * sv_setref_pvn(SV * const rv, const char * const classname,
const char * const pv, const STRLEN n)
"sv_setref_pvs"
Like "sv_setref_pvn", but takes a literal string instead of a string/length pair.
SV * sv_setref_pvs(SV *const rv, const char *const classname,
"literal string")
"sv_setref_uv"
Copies an unsigned integer into a new SV, optionally blessing the SV. The "rv"
argument will be upgraded to an RV. That RV will be modified to point to the new SV.
The "classname" argument indicates the package for the blessing. Set "classname" to
"NULL" to avoid the blessing. The new SV will have a reference count of 1, and the RV
will be returned.
SV * sv_setref_uv(SV * const rv, const char * const classname,
const UV uv)
"sv_setrv_inc"
"sv_setrv_inc_mg"
As "sv_setrv_noinc" but increments the reference count of ref.
"sv_setrv_inc_mg" will invoke 'set' magic on the SV; "sv_setrv_inc" will not.
void sv_setrv_inc(SV * const sv, SV * const ref)
"sv_setrv_noinc"
"sv_setrv_noinc_mg"
Copies an SV pointer into the given SV as an SV reference, upgrading it if necessary.
After this, SvRV(sv) is equal to ref. This does not adjust the reference count of ref.
The reference ref must not be NULL.
"sv_setrv_noinc_mg" will invoke 'set' magic on the SV; "sv_setrv_noinc" will not.
void sv_setrv_noinc(SV * const sv, SV * const ref)
"sv_setsv"
"sv_setsv_flags"
"sv_setsv_mg"
"sv_setsv_nomg"
These copy the contents of the source SV "ssv" into the destination SV "dsv". "ssv"
may be destroyed if it is mortal, so don't use these functions if the source SV needs
to be reused. Loosely speaking, they perform a copy-by-value, obliterating any
previous content of the destination.
They differ only in that:
"sv_setsv" calls 'get' magic on "ssv", but skips 'set' magic on "dsv".
"sv_setsv_mg" calls both 'get' magic on "ssv" and 'set' magic on "dsv".
"sv_setsv_nomg" skips all magic.
"sv_setsv_flags" has a "flags" parameter which you can use to specify any combination
of magic handling, and also you can specify "SV_NOSTEAL" so that the buffers of temps
will not be stolen.
You probably want to instead use one of the assortment of wrappers, such as "SvSetSV",
"SvSetSV_nosteal", "SvSetMagicSV" and "SvSetMagicSV_nosteal".
"sv_setsv_flags" is the primary function for copying scalars, and most other copy-ish
functions and macros use it underneath.
void sv_setsv (SV *dsv, SV *ssv)
void sv_setsv_flags(SV *dsv, SV *ssv, const I32 flags)
void sv_setsv_mg (SV * const dsv, SV * const ssv)
void sv_setsv_nomg (SV *dsv, SV *ssv)
"sv_set_true"
Equivalent to "sv_setsv(sv, &PL_sv_yes)", but may be made more efficient in the
future. Doesn't handle set magic.
The perl equivalent is "$sv = !0;".
Introduced in perl 5.35.11.
void sv_set_true(SV *sv)
"sv_set_undef"
Equivalent to "sv_setsv(sv, &PL_sv_undef)", but more efficient. Doesn't handle set
magic.
The perl equivalent is "$sv = undef;". Note that it doesn't free any string buffer,
unlike "undef $sv".
Introduced in perl 5.25.12.
void sv_set_undef(SV *sv)
"sv_setuv"
"sv_setuv_mg"
These copy an unsigned integer into the given SV, upgrading first if necessary.
They differ only in that "sv_setuv_mg" handles 'set' magic; "sv_setuv" does not.
void sv_setuv (SV * const sv, const UV num)
void sv_setuv_mg(SV * const sv, const UV u)
"SvSHARE"
Arranges for "sv" to be shared between threads if a suitable module has been loaded.
void SvSHARE(SV* sv)
"SvSHARED_HASH"
Returns the hash for "sv" created by "newSVpvn_share".
struct hek* SvSHARED_HASH(SV * sv)
"SvSTASH"
Returns the stash of the SV.
HV* SvSTASH(SV* sv)
"SvSTASH_set"
Set the value of the STASH pointer in "sv" to val. See "SvIV_set".
void SvSTASH_set(SV* sv, HV* val)
"sv_streq"
A convenient shortcut for calling "sv_streq_flags" with the "SV_GMAGIC" flag. This
function basically behaves like the Perl code "$sv1 eq $sv2".
bool sv_streq(SV *sv1, SV *sv2)
"sv_streq_flags"
Returns a boolean indicating whether the strings in the two SVs are identical. If the
flags argument has the "SV_GMAGIC" bit set, it handles get-magic too. Will coerce its
args to strings if necessary. Treats "NULL" as undef. Correctly handles the UTF8 flag.
If flags does not have the "SV_SKIP_OVERLOAD" bit set, an attempt to use "eq"
overloading will be made. If such overloading does not exist or the flag is set, then
regular string comparison will be used instead.
bool sv_streq_flags(SV *sv1, SV *sv2, const U32 flags)
"SvTRUE"
"SvTRUE_NN"
"SvTRUE_nomg"
"SvTRUE_nomg_NN"
"SvTRUEx"
These return a boolean indicating whether Perl would evaluate the SV as true or false.
See "SvOK" for a defined/undefined test.
As of Perl 5.32, all are guaranteed to evaluate "sv" only once. Prior to that
release, only "SvTRUEx" guaranteed single evaluation; now "SvTRUEx" is identical to
"SvTRUE".
"SvTRUE_nomg" and "TRUE_nomg_NN" do not perform 'get' magic; the others do unless the
scalar is already "SvPOK", "SvIOK", or "SvNOK" (the public, not the private flags).
"SvTRUE_NN" is like "SvTRUE", but "sv" is assumed to be non-null (NN). If there is a
possibility that it is NULL, use plain "SvTRUE".
"SvTRUE_nomg_NN" is like "SvTRUE_nomg", but "sv" is assumed to be non-null (NN). If
there is a possibility that it is NULL, use plain "SvTRUE_nomg".
bool SvTRUE(SV *sv)
"SvTYPE"
Returns the type of the SV. See "svtype".
svtype SvTYPE(SV* sv)
"SvUNLOCK"
Releases a mutual exclusion lock on "sv" if a suitable module has been loaded.
void SvUNLOCK(SV* sv)
"sv_unmagic"
Removes all magic of type "type" from an SV.
int sv_unmagic(SV * const sv, const int type)
"sv_unmagicext"
Removes all magic of type "type" with the specified "vtbl" from an SV.
int sv_unmagicext(SV * const sv, const int type,
const MGVTBL *vtbl)
"sv_unref"
Unsets the RV status of the SV, and decrements the reference count of whatever was
being referenced by the RV. This can almost be thought of as a reversal of "newSVrv".
This is "sv_unref_flags" with the "flag" being zero. See "SvROK_off".
void sv_unref(SV *sv)
"sv_unref_flags"
Unsets the RV status of the SV, and decrements the reference count of whatever was
being referenced by the RV. This can almost be thought of as a reversal of "newSVrv".
The "cflags" argument can contain "SV_IMMEDIATE_UNREF" to force the reference count to
be decremented (otherwise the decrementing is conditional on the reference count being
different from one or the reference being a readonly SV). See "SvROK_off".
void sv_unref_flags(SV * const ref, const U32 flags)
"SvUOK"
Returns a boolean indicating whether the SV contains an integer that must be
interpreted as unsigned. A non-negative integer whose value is within the range of
both an IV and a UV may be flagged as either "SvUOK" or "SvIOK".
bool SvUOK(SV* sv)
"SvUPGRADE"
Used to upgrade an SV to a more complex form. Uses "sv_upgrade" to perform the
upgrade if necessary. See "svtype".
void SvUPGRADE(SV* sv, svtype type)
"sv_upgrade"
Upgrade an SV to a more complex form. Generally adds a new body type to the SV, then
copies across as much information as possible from the old body. It croaks if the SV
is already in a more complex form than requested. You generally want to use the
"SvUPGRADE" macro wrapper, which checks the type before calling "sv_upgrade", and
hence does not croak. See also "svtype".
void sv_upgrade(SV * const sv, svtype new_type)
"sv_usepvn"
"sv_usepvn_flags"
"sv_usepvn_mg"
These tell an SV to use "ptr" for its string value. Normally SVs have their string
stored inside the SV, but these tell the SV to use an external string instead.
"ptr" should point to memory that was allocated by ""Newx"". It must be the start of
a "Newx"-ed block of memory, and not a pointer to the middle of it (beware of "OOK"
and copy-on-write), and not be from a non-"Newx" memory allocator like "malloc". The
string length, "len", must be supplied. By default this function will ""Renew"" (i.e.
realloc, move) the memory pointed to by "ptr", so that the pointer should not be freed
or used by the programmer after giving it to "sv_usepvn", and neither should any
pointers from "behind" that pointer (e.g., "ptr" + 1) be used.
In the "sv_usepvn_flags" form, if "flags & SV_SMAGIC" is true, "SvSETMAGIC" is called
before returning. And if "flags & SV_HAS_TRAILING_NUL" is true, then "ptr[len]" must
be "NUL", and the realloc will be skipped (i.e., the buffer is actually at least 1
byte longer than "len", and already meets the requirements for storing in "SvPVX").
"sv_usepvn" is merely "sv_usepvn_flags" with "flags" set to 0, so 'set' magic is
skipped.
"sv_usepvn_mg" is merely "sv_usepvn_flags" with "flags" set to "SV_SMAGIC", so 'set'
magic is performed.
void sv_usepvn (SV *sv, char *ptr, STRLEN len)
void sv_usepvn_flags(SV * const sv, char *ptr, const STRLEN len,
const U32 flags)
void sv_usepvn_mg (SV *sv, char *ptr, STRLEN len)
"sv_utf8_decode"
If the PV of the SV is an octet sequence in Perl's extended UTF-8 and contains a
multiple-byte character, the "SvUTF8" flag is turned on so that it looks like a
character. If the PV contains only single-byte characters, the "SvUTF8" flag stays
off. Scans PV for validity and returns FALSE if the PV is invalid UTF-8.
bool sv_utf8_decode(SV * const sv)
"sv_utf8_downgrade"
"sv_utf8_downgrade_flags"
"sv_utf8_downgrade_nomg"
These attempt to convert the PV of an SV from characters to bytes. If the PV contains
a character that cannot fit in a byte, this conversion will fail; in this case,
"FALSE" is returned if "fail_ok" is true; otherwise they croak.
They are not a general purpose Unicode to byte encoding interface: use the "Encode"
extension for that.
They differ only in that:
"sv_utf8_downgrade" processes 'get' magic on "sv".
"sv_utf8_downgrade_nomg" does not.
"sv_utf8_downgrade_flags" has an additional "flags" parameter in which you can specify
"SV_GMAGIC" to process 'get' magic, or leave it cleared to not process 'get' magic.
bool sv_utf8_downgrade (SV * const sv, const bool fail_ok)
bool sv_utf8_downgrade_flags(SV * const sv, const bool fail_ok,
const U32 flags)
bool sv_utf8_downgrade_nomg (SV * const sv, const bool fail_ok)
"sv_utf8_encode"
Converts the PV of an SV to UTF-8, but then turns the "SvUTF8" flag off so that it
looks like octets again.
void sv_utf8_encode(SV * const sv)
"SvUTF8_off"
Unsets the UTF-8 status of an SV (the data is not changed, just the flag). Do not use
frivolously.
void SvUTF8_off(SV *sv)
"SvUTF8_on"
Turn on the UTF-8 status of an SV (the data is not changed, just the flag). Do not
use frivolously.
void SvUTF8_on(SV *sv)
"sv_utf8_upgrade"
"sv_utf8_upgrade_flags"
"sv_utf8_upgrade_flags_grow"
"sv_utf8_upgrade_nomg"
These convert the PV of an SV to its UTF-8-encoded form. The SV is forced to string
form if it is not already. They always set the "SvUTF8" flag to avoid future validity
checks even if the whole string is the same in UTF-8 as not. They return the number
of bytes in the converted string
The forms differ in just two ways. The main difference is whether or not they perform
'get magic' on "sv". "sv_utf8_upgrade_nomg" skips 'get magic'; "sv_utf8_upgrade"
performs it; and "sv_utf8_upgrade_flags" and "sv_utf8_upgrade_flags_grow" either
perform it (if the "SV_GMAGIC" bit is set in "flags") or don't (if that bit is
cleared).
The other difference is that "sv_utf8_upgrade_flags_grow" has an additional parameter,
"extra", which allows the caller to specify an amount of space to be reserved as spare
beyond what is needed for the actual conversion. This is used when the caller knows
it will soon be needing yet more space, and it is more efficient to request space from
the system in a single call. This form is otherwise identical to
"sv_utf8_upgrade_flags".
These are not a general purpose byte encoding to Unicode interface: use the Encode
extension for that.
The "SV_FORCE_UTF8_UPGRADE" flag is now ignored.
STRLEN sv_utf8_upgrade (SV *sv)
STRLEN sv_utf8_upgrade_flags (SV * const sv, const I32 flags)
STRLEN sv_utf8_upgrade_flags_grow(SV * const sv, const I32 flags,
STRLEN extra)
STRLEN sv_utf8_upgrade_nomg (SV *sv)
"SvUTF8"
Returns a U32 value indicating the UTF-8 status of an SV. If things are set-up
properly, this indicates whether or not the SV contains UTF-8 encoded data. You
should use this after a call to "SvPV" or one of its variants, in case any call to
string overloading updates the internal flag.
If you want to take into account the bytes pragma, use "DO_UTF8" instead.
U32 SvUTF8(SV* sv)
"SvUV"
"SvUV_nomg"
"SvUVx"
These each coerce the given SV to UV and return it. The returned value in many
circumstances will get stored in "sv"'s UV slot, but not in all cases. (Use
"sv_setuv" to make sure it does).
As of 5.37.1, all are guaranteed to evaluate "sv" only once.
"SvUVx" is now identical to "SvUV", but prior to 5.37.1, it was the only form
guaranteed to evaluate "sv" only once.
UV SvUV(SV *sv)
"sv_2uv_flags"
Return the unsigned integer value of an SV, doing any necessary string conversion. If
"flags" has the "SV_GMAGIC" bit set, does an mg_get() first. Normally used via the
SvUV(sv) and SvUVx(sv) macros.
UV sv_2uv_flags(SV * const sv, const I32 flags)
"SvUV_set"
Set the value of the UV pointer in "sv" to val. See "SvIV_set".
void SvUV_set(SV* sv, UV val)
"SvUVX"
Returns the raw value in the SV's UV slot, without checks or conversions. Only use
when you are sure "SvIOK" is true. See also "SvUV".
UV SvUVX(SV* sv)
"SvUVXx"
"DEPRECATED!" It is planned to remove "SvUVXx" from a future release of Perl. Do not
use it for new code; remove it from existing code.
This is an unnecessary synonym for "SvUVX"
UV SvUVXx(SV* sv)
"sv_vcatpvf"
"sv_vcatpvf_mg"
These process their arguments like "sv_vcatpvfn" called with a non-null C-style
variable argument list, and append the formatted output to "sv".
They differ only in that "sv_vcatpvf_mg" performs 'set' magic; "sv_vcatpvf" skips
'set' magic.
Both perform 'get' magic.
They are usually accessed via their frontends "sv_catpvf" and "sv_catpvf_mg".
void sv_vcatpvf(SV * const sv, const char * const pat,
va_list * const args)
"sv_vcatpvfn"
"sv_vcatpvfn_flags"
These process their arguments like vsprintf(3) and append the formatted output to an
SV. They use an array of SVs if the C-style variable argument list is missing
("NULL"). Argument reordering (using format specifiers like "%2$d" or "%*2$d") is
supported only when using an array of SVs; using a C-style "va_list" argument list
with a format string that uses argument reordering will yield an exception.
When running with taint checks enabled, they indicate via "maybe_tainted" if results
are untrustworthy (often due to the use of locales).
They assume that "pat" has the same utf8-ness as "sv". It's the caller's
responsibility to ensure that this is so.
They differ in that "sv_vcatpvfn_flags" has a "flags" parameter in which you can set
or clear the "SV_GMAGIC" and/or SV_SMAGIC flags, to specify which magic to handle or
not handle; whereas plain "sv_vcatpvfn" always specifies both 'get' and 'set' magic.
They are usually used via one of the frontends ""sv_vcatpvf"" and ""sv_vcatpvf_mg"".
void sv_vcatpvfn (SV * const sv, const char * const pat,
const STRLEN patlen, va_list * const args,
SV ** const svargs, const Size_t sv_count,
bool * const maybe_tainted)
void sv_vcatpvfn_flags(SV * const sv, const char * const pat,
const STRLEN patlen, va_list * const args,
SV ** const svargs, const Size_t sv_count,
bool * const maybe_tainted,
const U32 flags)
"SvVOK"
Returns a boolean indicating whether the SV contains a v-string.
bool SvVOK(SV* sv)
"sv_vsetpvf"
"sv_vsetpvf_mg"
These work like "sv_vcatpvf" but copy the text into the SV instead of appending it.
They differ only in that "sv_vsetpvf_mg" performs 'set' magic; "sv_vsetpvf" skips all
magic.
They are usually used via their frontends, "sv_setpvf" and "sv_setpvf_mg".
The UTF-8 flag is not changed by these functions.
void sv_vsetpvf(SV * const sv, const char * const pat,
va_list * const args)
"sv_vsetpvfn"
Works like "sv_vcatpvfn" but copies the text into the SV instead of appending it.
The UTF-8 flag is not changed by this function.
Usually used via one of its frontends ""sv_vsetpvf"" and ""sv_vsetpvf_mg"".
void sv_vsetpvfn(SV * const sv, const char * const pat,
const STRLEN patlen, va_list * const args,
SV ** const svargs, const Size_t sv_count,
bool * const maybe_tainted)
"SvVSTRING_mg"
Returns the vstring magic, or NULL if none
MAGIC* SvVSTRING_mg(SV * sv)
"vnewSVpvf"
Like "newSVpvf" but the arguments are an encapsulated argument list.
SV * vnewSVpvf(const char * const pat, va_list * const args)
Tainting
"SvTAINT"
Taints an SV if tainting is enabled, and if some input to the current expression is
tainted--usually a variable, but possibly also implicit inputs such as locale
settings. "SvTAINT" propagates that taintedness to the outputs of an expression in a
pessimistic fashion; i.e., without paying attention to precisely which outputs are
influenced by which inputs.
void SvTAINT(SV* sv)
"SvTAINTED"
Checks to see if an SV is tainted. Returns TRUE if it is, FALSE if not.
bool SvTAINTED(SV* sv)
"SvTAINTED_off"
Untaints an SV. Be very careful with this routine, as it short-circuits some of
Perl's fundamental security features. XS module authors should not use this function
unless they fully understand all the implications of unconditionally untainting the
value. Untainting should be done in the standard perl fashion, via a carefully
crafted regexp, rather than directly untainting variables.
void SvTAINTED_off(SV* sv)
"SvTAINTED_on"
Marks an SV as tainted if tainting is enabled.
void SvTAINTED_on(SV* sv)
Time
"ASCTIME_R_PROTO"
This symbol encodes the prototype of "asctime_r". It is zero if "d_asctime_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_asctime_r" is
defined.
"CTIME_R_PROTO"
This symbol encodes the prototype of "ctime_r". It is zero if "d_ctime_r" is undef,
and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_ctime_r" is defined.
"GMTIME_MAX"
This symbol contains the maximum value for the "time_t" offset that the system
function gmtime () accepts, and defaults to 0
"GMTIME_MIN"
This symbol contains the minimum value for the "time_t" offset that the system
function gmtime () accepts, and defaults to 0
"GMTIME_R_PROTO"
This symbol encodes the prototype of "gmtime_r". It is zero if "d_gmtime_r" is undef,
and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_gmtime_r" is defined.
"HAS_ASCTIME_R"
This symbol, if defined, indicates that the "asctime_r" routine is available to
asctime re-entrantly.
"HAS_ASCTIME64"
This symbol, if defined, indicates that the "asctime64" () routine is available to do
the 64bit variant of asctime ()
"HAS_CTIME_R"
This symbol, if defined, indicates that the "ctime_r" routine is available to ctime
re-entrantly.
"HAS_CTIME64"
This symbol, if defined, indicates that the "ctime64" () routine is available to do
the 64bit variant of ctime ()
"HAS_DIFFTIME"
This symbol, if defined, indicates that the "difftime" routine is available.
"HAS_DIFFTIME64"
This symbol, if defined, indicates that the "difftime64" () routine is available to do
the 64bit variant of difftime ()
"HAS_FUTIMES"
This symbol, if defined, indicates that the "futimes" routine is available to change
file descriptor time stamps with "struct timevals".
"HAS_GETITIMER"
This symbol, if defined, indicates that the "getitimer" routine is available to return
interval timers.
"HAS_GETTIMEOFDAY"
This symbol, if defined, indicates that the gettimeofday() system call is available
for a sub-second accuracy clock. Usually, the file sys/resource.h needs to be included
(see "I_SYS_RESOURCE"). The type "Timeval" should be used to refer to ""struct
timeval"".
"HAS_GMTIME_R"
This symbol, if defined, indicates that the "gmtime_r" routine is available to gmtime
re-entrantly.
"HAS_GMTIME64"
This symbol, if defined, indicates that the "gmtime64" () routine is available to do
the 64bit variant of gmtime ()
"HAS_LOCALTIME_R"
This symbol, if defined, indicates that the "localtime_r" routine is available to
localtime re-entrantly.
"HAS_LOCALTIME64"
This symbol, if defined, indicates that the "localtime64" () routine is available to
do the 64bit variant of localtime ()
"HAS_MKTIME"
This symbol, if defined, indicates that the "mktime" routine is available.
"HAS_MKTIME64"
This symbol, if defined, indicates that the "mktime64" () routine is available to do
the 64bit variant of mktime ()
"HAS_NANOSLEEP"
This symbol, if defined, indicates that the "nanosleep" system call is available to
sleep with 1E-9 sec accuracy.
"HAS_SETITIMER"
This symbol, if defined, indicates that the "setitimer" routine is available to set
interval timers.
"HAS_STRFTIME"
This symbol, if defined, indicates that the "strftime" routine is available to do time
formatting.
"HAS_TIME"
This symbol, if defined, indicates that the time() routine exists.
"HAS_TIMEGM"
This symbol, if defined, indicates that the "timegm" routine is available to do the
opposite of gmtime ()
"HAS_TIMES"
This symbol, if defined, indicates that the times() routine exists. Note that this
became obsolete on some systems ("SUNOS"), which now use getrusage(). It may be
necessary to include sys/times.h.
"HAS_TM_TM_GMTOFF"
This symbol, if defined, indicates to the C program that the "struct tm" has a
"tm_gmtoff" field.
"HAS_TM_TM_ZONE"
This symbol, if defined, indicates to the C program that the "struct tm" has a
"tm_zone" field.
"HAS_TZNAME"
This symbol, if defined, indicates that the "tzname[]" array is available to access
timezone names.
"HAS_USLEEP"
This symbol, if defined, indicates that the "usleep" routine is available to let the
process sleep on a sub-second accuracy.
"HAS_USLEEP_PROTO"
This symbol, if defined, indicates that the system provides a prototype for the
usleep() function. Otherwise, it is up to the program to supply one. A good guess is
extern int usleep(useconds_t);
"I_TIME"
This symbol is always defined, and indicates to the C program that it should include
time.h.
#ifdef I_TIME
#include <time.h>
#endif
"I_UTIME"
This symbol, if defined, indicates to the C program that it should include utime.h.
#ifdef I_UTIME
#include <utime.h>
#endif
"LOCALTIME_MAX"
This symbol contains the maximum value for the "time_t" offset that the system
function localtime () accepts, and defaults to 0
"LOCALTIME_MIN"
This symbol contains the minimum value for the "time_t" offset that the system
function localtime () accepts, and defaults to 0
"LOCALTIME_R_NEEDS_TZSET"
Many libc's "localtime_r" implementations do not call tzset, making them differ from
localtime(), and making timezone changes using $"ENV"{TZ} without explicitly calling
tzset impossible. This symbol makes us call tzset before "localtime_r"
"LOCALTIME_R_PROTO"
This symbol encodes the prototype of "localtime_r". It is zero if "d_localtime_r" is
undef, and one of the "REENTRANT_PROTO_T_ABC" macros of reentr.h if "d_localtime_r" is
defined.
"L_R_TZSET"
If localtime_r() needs tzset, it is defined in this define
"mini_mktime"
normalise "struct tm" values without the localtime() semantics (and overhead) of
mktime().
void mini_mktime(struct tm *ptm)
"sv_strftime_tm"
"my_strftime"
These implement the libc strftime().
On failure, they return NULL, and set "errno" to "EINVAL".
"sv_strftime_tm" is preferred, as it transparently handles the UTF-8ness of the
current locale, the input "fmt", and the returned result. Only if the current
"LC_TIME" locale is a UTF-8 one (and "use bytes" is not in effect) will the result be
marked as UTF-8.
"sv_strftime_tm" takes a pointer to a filled-in "struct tm" parameter. It ignores the
values of the "wday" and "yday" fields in it. The other fields give enough
information to accurately calculate these values, and are used for that purpose.
The caller assumes ownership of the returned SV with a reference count of 1.
"my_strftime" is kept for backwards compatibility. Knowing if its result should be
considered UTF-8 or not requires significant extra logic.
The return value is a pointer to the formatted result (which MUST be arranged to be
FREED BY THE CALLER). This allows this function to increase the buffer size as
needed, so that the caller doesn't have to worry about that, unlike libc strftime().
The "wday", "yday", and "isdst" parameters are ignored by "my_strftime". Daylight
savings time is never considered to exist, and the values returned for the other two
fields (if "fmt" even calls for them) are calculated from the other parameters,
without need for referencing these.
Note that both functions are always executed in the underlying "LC_TIME" locale of the
program, giving results based on that locale.
SV * sv_strftime_tm(SV *fmt, const struct tm *mytm)
char * my_strftime (const char *fmt, int sec, int min,
int hour, int mday, int mon, int year,
int wday, int yday, int isdst)
Typedef names
"DB_Hash_t"
This symbol contains the type of the prefix structure element in the db.h header file.
In older versions of DB, it was int, while in newer ones it is "size_t".
"DB_Prefix_t"
This symbol contains the type of the prefix structure element in the db.h header file.
In older versions of DB, it was int, while in newer ones it is "u_int32_t".
"Direntry_t"
This symbol is set to '"struct direct"' or '"struct dirent"' depending on whether
dirent is available or not. You should use this pseudo type to portably declare your
directory entries.
"Fpos_t"
This symbol holds the type used to declare file positions in libc. It can be
"fpos_t", long, uint, etc... It may be necessary to include sys/types.h to get any
typedef'ed information.
"Free_t"
This variable contains the return type of free(). It is usually void, but
occasionally int.
"Gid_t"
This symbol holds the return type of getgid() and the type of argument to setrgid()
and related functions. Typically, it is the type of group ids in the kernel. It can
be int, ushort, "gid_t", etc... It may be necessary to include sys/types.h to get any
typedef'ed information.
"Gid_t_f"
This symbol defines the format string used for printing a "Gid_t".
"Gid_t_sign"
This symbol holds the signedness of a "Gid_t". 1 for unsigned, -1 for signed.
"Gid_t_size"
This symbol holds the size of a "Gid_t" in bytes.
"Groups_t"
This symbol holds the type used for the second argument to getgroups() and
setgroups(). Usually, this is the same as gidtype ("gid_t") , but sometimes it isn't.
It can be int, ushort, "gid_t", etc... It may be necessary to include sys/types.h to
get any typedef'ed information. This is only required if you have getgroups() or
setgroups()..
"Malloc_t"
This symbol is the type of pointer returned by malloc and realloc.
"Mmap_t"
This symbol holds the return type of the mmap() system call (and simultaneously the
type of the first argument). Usually set to 'void *' or '"caddr_t"'.
"Mode_t"
This symbol holds the type used to declare file modes for systems calls. It is
usually "mode_t", but may be int or unsigned short. It may be necessary to include
sys/types.h to get any typedef'ed information.
"Netdb_hlen_t"
This symbol holds the type used for the 2nd argument to gethostbyaddr().
"Netdb_host_t"
This symbol holds the type used for the 1st argument to gethostbyaddr().
"Netdb_name_t"
This symbol holds the type used for the argument to gethostbyname().
"Netdb_net_t"
This symbol holds the type used for the 1st argument to getnetbyaddr().
"Off_t"
This symbol holds the type used to declare offsets in the kernel. It can be int,
long, "off_t", etc... It may be necessary to include sys/types.h to get any typedef'ed
information.
"Off_t_size"
This symbol holds the number of bytes used by the "Off_t".
"Pid_t"
This symbol holds the type used to declare process ids in the kernel. It can be int,
uint, "pid_t", etc... It may be necessary to include sys/types.h to get any typedef'ed
information.
"Rand_seed_t"
This symbol defines the type of the argument of the random seed function.
"Select_fd_set_t"
This symbol holds the type used for the 2nd, 3rd, and 4th arguments to select.
Usually, this is '"fd_set" *', if "HAS_FD_SET" is defined, and 'int *' otherwise.
This is only useful if you have select(), of course.
"Shmat_t"
This symbol holds the return type of the shmat() system call. Usually set to 'void *'
or 'char *'.
"Signal_t"
This symbol's value is either "void" or "int", corresponding to the appropriate return
type of a signal handler. Thus, you can declare a signal handler using ""Signal_t"
(*handler)()", and define the handler using ""Signal_t" handler(sig)".
"Size_t"
This symbol holds the type used to declare length parameters for string functions. It
is usually "size_t", but may be unsigned long, int, etc. It may be necessary to
include sys/types.h to get any typedef'ed information.
"Size_t_size"
This symbol holds the size of a "Size_t" in bytes.
"Sock_size_t"
This symbol holds the type used for the size argument of various socket calls (just
the base type, not the pointer-to).
"SSize_t"
This symbol holds the type used by functions that return a count of bytes or an error
condition. It must be a signed type. It is usually "ssize_t", but may be long or
int, etc. It may be necessary to include sys/types.h or unistd.h to get any
typedef'ed information. We will pick a type such that sizeof(SSize_t) ==
sizeof(Size_t).
"Time_t"
This symbol holds the type returned by time(). It can be long, or "time_t" on "BSD"
sites (in which case sys/types.h should be included).
"Uid_t"
This symbol holds the type used to declare user ids in the kernel. It can be int,
ushort, "uid_t", etc... It may be necessary to include sys/types.h to get any
typedef'ed information.
"Uid_t_f"
This symbol defines the format string used for printing a "Uid_t".
"Uid_t_sign"
This symbol holds the signedness of a "Uid_t". 1 for unsigned, -1 for signed.
"Uid_t_size"
This symbol holds the size of a "Uid_t" in bytes.
Unicode Support
"Unicode Support" in perlguts has an introduction to this API.
See also "Character classification", "Character case changing", and "String Handling".
Various functions outside this section also work specially with Unicode. Search for the
string "utf8" in this document.
"BOM_UTF8"
This is a macro that evaluates to a string constant of the UTF-8 bytes that define
the Unicode BYTE ORDER MARK (U+FEFF) for the platform that perl is compiled on. This
allows code to use a mnemonic for this character that works on both ASCII and EBCDIC
platforms. "sizeof(BOM_UTF8) - 1" can be used to get its length in bytes.
"bytes_cmp_utf8"
Compares the sequence of characters (stored as octets) in "b", "blen" with the
sequence of characters (stored as UTF-8) in "u", "ulen". Returns 0 if they are equal,
-1 or -2 if the first string is less than the second string, +1 or +2 if the first
string is greater than the second string.
-1 or +1 is returned if the shorter string was identical to the start of the longer
string. -2 or +2 is returned if there was a difference between characters within the
strings.
int bytes_cmp_utf8(const U8 *b, STRLEN blen, const U8 *u,
STRLEN ulen)
"bytes_from_utf8"
NOTE: "bytes_from_utf8" is experimental and may change or be removed without notice.
Converts a potentially UTF-8 encoded string "s" of length *lenp into native byte
encoding. On input, the boolean *is_utf8p gives whether or not "s" is actually
encoded in UTF-8.
Unlike "utf8_to_bytes" but like "bytes_to_utf8", this is non-destructive of the input
string.
Do nothing if *is_utf8p is 0, or if there are code points in the string not
expressible in native byte encoding. In these cases, *is_utf8p and *lenp are
unchanged, and the return value is the original "s".
Otherwise, *is_utf8p is set to 0, and the return value is a pointer to a newly created
string containing a downgraded copy of "s", and whose length is returned in *lenp,
updated. The new string is "NUL"-terminated. The caller is responsible for arranging
for the memory used by this string to get freed.
Upon successful return, the number of variants in the string can be computed by having
saved the value of *lenp before the call, and subtracting the after-call value of
*lenp from it.
U8 * bytes_from_utf8(const U8 *s, STRLEN *lenp, bool *is_utf8p)
"bytes_to_utf8"
NOTE: "bytes_to_utf8" is experimental and may change or be removed without notice.
Converts a string "s" of length *lenp bytes from the native encoding into UTF-8.
Returns a pointer to the newly-created string, and sets *lenp to reflect the new
length in bytes. The caller is responsible for arranging for the memory used by this
string to get freed.
Upon successful return, the number of variants in the string can be computed by having
saved the value of *lenp before the call, and subtracting it from the after-call value
of *lenp.
A "NUL" character will be written after the end of the string.
If you want to convert to UTF-8 from encodings other than the native (Latin1 or
EBCDIC), see "sv_recode_to_utf8"().
U8 * bytes_to_utf8(const U8 *s, STRLEN *lenp)
"DO_UTF8"
Returns a bool giving whether or not the PV in "sv" is to be treated as being encoded
in UTF-8.
You should use this after a call to SvPV() or one of its variants, in case any call to
string overloading updates the internal UTF-8 encoding flag.
bool DO_UTF8(SV* sv)
"foldEQ_utf8"
Returns true if the leading portions of the strings "s1" and "s2" (either or both of
which may be in UTF-8) are the same case-insensitively; false otherwise. How far into
the strings to compare is determined by other input parameters.
If "u1" is true, the string "s1" is assumed to be in UTF-8-encoded Unicode; otherwise
it is assumed to be in native 8-bit encoding. Correspondingly for "u2" with respect
to "s2".
If the byte length "l1" is non-zero, it says how far into "s1" to check for fold
equality. In other words, "s1"+"l1" will be used as a goal to reach. The scan will
not be considered to be a match unless the goal is reached, and scanning won't
continue past that goal. Correspondingly for "l2" with respect to "s2".
If "pe1" is non-"NULL" and the pointer it points to is not "NULL", that pointer is
considered an end pointer to the position 1 byte past the maximum point in "s1" beyond
which scanning will not continue under any circumstances. (This routine assumes that
UTF-8 encoded input strings are not malformed; malformed input can cause it to read
past "pe1"). This means that if both "l1" and "pe1" are specified, and "pe1" is less
than "s1"+"l1", the match will never be successful because it can never get as far as
its goal (and in fact is asserted against). Correspondingly for "pe2" with respect to
"s2".
At least one of "s1" and "s2" must have a goal (at least one of "l1" and "l2" must be
non-zero), and if both do, both have to be reached for a successful match. Also, if
the fold of a character is multiple characters, all of them must be matched (see tr21
reference below for 'folding').
Upon a successful match, if "pe1" is non-"NULL", it will be set to point to the
beginning of the next character of "s1" beyond what was matched. Correspondingly for
"pe2" and "s2".
For case-insensitiveness, the "casefolding" of Unicode is used instead of
upper/lowercasing both the characters, see <https://www.unicode.org/reports/tr21/>
(Case Mappings).
I32 foldEQ_utf8(const char *s1, char **pe1, UV l1, bool u1,
const char *s2, char **pe2, UV l2, bool u2)
"is_ascii_string"
This is a misleadingly-named synonym for "is_utf8_invariant_string". On ASCII-ish
platforms, the name isn't misleading: the ASCII-range characters are exactly the UTF-8
invariants. But EBCDIC machines have more invariants than just the ASCII characters,
so "is_utf8_invariant_string" is preferred.
bool is_ascii_string(const U8 * const s, STRLEN len)
"isC9_STRICT_UTF8_CHAR"
Evaluates to non-zero if the first few bytes of the string starting at "s" and looking
no further than "e - 1" are well-formed UTF-8 that represents some Unicode non-
surrogate code point; otherwise it evaluates to 0. If non-zero, the value gives how
many bytes starting at "s" comprise the code point's representation. Any bytes
remaining before "e", but beyond the ones needed to form the first code point in "s",
are not examined.
The largest acceptable code point is the Unicode maximum 0x10FFFF. This differs from
"isSTRICT_UTF8_CHAR" only in that it accepts non-character code points. This
corresponds to Unicode Corrigendum #9
<http://www.unicode.org/versions/corrigendum9.html>. which said that non-character
code points are merely discouraged rather than completely forbidden in open
interchange. See "Noncharacter code points" in perlunicode.
Use "isUTF8_CHAR" to check for Perl's extended UTF-8; and "isUTF8_CHAR_flags" for a
more customized definition.
Use "is_c9strict_utf8_string", "is_c9strict_utf8_string_loc", and
"is_c9strict_utf8_string_loclen" to check entire strings.
Size_t isC9_STRICT_UTF8_CHAR(const U8 * const s0,
const U8 * const e)
"is_c9strict_utf8_string"
Returns TRUE if the first "len" bytes of string "s" form a valid UTF-8-encoded string
that conforms to Unicode Corrigendum #9
<http://www.unicode.org/versions/corrigendum9.html>; otherwise it returns FALSE. If
"len" is 0, it will be calculated using strlen(s) (which means if you use this option,
that "s" can't have embedded "NUL" characters and has to have a terminating "NUL"
byte). Note that all characters being ASCII constitute 'a valid UTF-8 string'.
This function returns FALSE for strings containing any code points above the Unicode
max of 0x10FFFF or surrogate code points, but accepts non-character code points per
Corrigendum #9 <http://www.unicode.org/versions/corrigendum9.html>.
See also "is_utf8_invariant_string", "is_utf8_invariant_string_loc", "is_utf8_string",
"is_utf8_string_flags", "is_utf8_string_loc", "is_utf8_string_loc_flags",
"is_utf8_string_loclen", "is_utf8_string_loclen_flags",
"is_utf8_fixed_width_buf_flags", "is_utf8_fixed_width_buf_loc_flags",
"is_utf8_fixed_width_buf_loclen_flags", "is_strict_utf8_string",
"is_strict_utf8_string_loc", "is_strict_utf8_string_loclen",
"is_c9strict_utf8_string_loc", and "is_c9strict_utf8_string_loclen".
bool is_c9strict_utf8_string(const U8 *s, STRLEN len)
"is_c9strict_utf8_string_loc"
Like "is_c9strict_utf8_string" but stores the location of the failure (in the case of
"utf8ness failure") or the location "s"+"len" (in the case of "utf8ness success") in
the "ep" pointer.
See also "is_c9strict_utf8_string_loclen".
bool is_c9strict_utf8_string_loc(const U8 *s, STRLEN len,
const U8 **ep)
"is_c9strict_utf8_string_loclen"
Like "is_c9strict_utf8_string" but stores the location of the failure (in the case of
"utf8ness failure") or the location "s"+"len" (in the case of "utf8ness success") in
the "ep" pointer, and the number of UTF-8 encoded characters in the "el" pointer.
See also "is_c9strict_utf8_string_loc".
bool is_c9strict_utf8_string_loclen(const U8 *s, STRLEN len,
const U8 **ep, STRLEN *el)
"is_invariant_string"
This is a somewhat misleadingly-named synonym for "is_utf8_invariant_string".
"is_utf8_invariant_string" is preferred, as it indicates under what conditions the
string is invariant.
bool is_invariant_string(const U8 * const s, STRLEN len)
"isSTRICT_UTF8_CHAR"
Evaluates to non-zero if the first few bytes of the string starting at "s" and looking
no further than "e - 1" are well-formed UTF-8 that represents some Unicode code point
completely acceptable for open interchange between all applications; otherwise it
evaluates to 0. If non-zero, the value gives how many bytes starting at "s" comprise
the code point's representation. Any bytes remaining before "e", but beyond the ones
needed to form the first code point in "s", are not examined.
The largest acceptable code point is the Unicode maximum 0x10FFFF, and must not be a
surrogate nor a non-character code point. Thus this excludes any code point from
Perl's extended UTF-8.
This is used to efficiently decide if the next few bytes in "s" is legal Unicode-
acceptable UTF-8 for a single character.
Use "isC9_STRICT_UTF8_CHAR" to use the Unicode Corrigendum #9
<http://www.unicode.org/versions/corrigendum9.html> definition of allowable code
points; "isUTF8_CHAR" to check for Perl's extended UTF-8; and "isUTF8_CHAR_flags" for
a more customized definition.
Use "is_strict_utf8_string", "is_strict_utf8_string_loc", and
"is_strict_utf8_string_loclen" to check entire strings.
Size_t isSTRICT_UTF8_CHAR(const U8 * const s0,
const U8 * const e)
"is_strict_utf8_string"
Returns TRUE if the first "len" bytes of string "s" form a valid UTF-8-encoded string
that is fully interchangeable by any application using Unicode rules; otherwise it
returns FALSE. If "len" is 0, it will be calculated using strlen(s) (which means if
you use this option, that "s" can't have embedded "NUL" characters and has to have a
terminating "NUL" byte). Note that all characters being ASCII constitute 'a valid
UTF-8 string'.
This function returns FALSE for strings containing any code points above the Unicode
max of 0x10FFFF, surrogate code points, or non-character code points.
See also "is_utf8_invariant_string", "is_utf8_invariant_string_loc", "is_utf8_string",
"is_utf8_string_flags", "is_utf8_string_loc", "is_utf8_string_loc_flags",
"is_utf8_string_loclen", "is_utf8_string_loclen_flags",
"is_utf8_fixed_width_buf_flags", "is_utf8_fixed_width_buf_loc_flags",
"is_utf8_fixed_width_buf_loclen_flags", "is_strict_utf8_string_loc",
"is_strict_utf8_string_loclen", "is_c9strict_utf8_string",
"is_c9strict_utf8_string_loc", and "is_c9strict_utf8_string_loclen".
bool is_strict_utf8_string(const U8 *s, STRLEN len)
"is_strict_utf8_string_loc"
Like "is_strict_utf8_string" but stores the location of the failure (in the case of
"utf8ness failure") or the location "s"+"len" (in the case of "utf8ness success") in
the "ep" pointer.
See also "is_strict_utf8_string_loclen".
bool is_strict_utf8_string_loc(const U8 *s, STRLEN len,
const U8 **ep)
"is_strict_utf8_string_loclen"
Like "is_strict_utf8_string" but stores the location of the failure (in the case of
"utf8ness failure") or the location "s"+"len" (in the case of "utf8ness success") in
the "ep" pointer, and the number of UTF-8 encoded characters in the "el" pointer.
See also "is_strict_utf8_string_loc".
bool is_strict_utf8_string_loclen(const U8 *s, STRLEN len,
const U8 **ep, STRLEN *el)
"isUTF8_CHAR"
Evaluates to non-zero if the first few bytes of the string starting at "s" and looking
no further than "e - 1" are well-formed UTF-8, as extended by Perl, that represents
some code point; otherwise it evaluates to 0. If non-zero, the value gives how many
bytes starting at "s" comprise the code point's representation. Any bytes remaining
before "e", but beyond the ones needed to form the first code point in "s", are not
examined.
The code point can be any that will fit in an IV on this machine, using Perl's
extension to official UTF-8 to represent those higher than the Unicode maximum of
0x10FFFF. That means that this macro is used to efficiently decide if the next few
bytes in "s" is legal UTF-8 for a single character.
Use "isSTRICT_UTF8_CHAR" to restrict the acceptable code points to those defined by
Unicode to be fully interchangeable across applications; "isC9_STRICT_UTF8_CHAR" to
use the Unicode Corrigendum #9 <http://www.unicode.org/versions/corrigendum9.html>
definition of allowable code points; and "isUTF8_CHAR_flags" for a more customized
definition.
Use "is_utf8_string", "is_utf8_string_loc", and "is_utf8_string_loclen" to check
entire strings.
Note also that a UTF-8 "invariant" character (i.e. ASCII on non-EBCDIC machines) is a
valid UTF-8 character.
Size_t isUTF8_CHAR(const U8 * const s0, const U8 * const e)
"is_utf8_char_buf"
This is identical to the macro "isUTF8_CHAR" in perlapi.
STRLEN is_utf8_char_buf(const U8 *buf, const U8 *buf_end)
"isUTF8_CHAR_flags"
Evaluates to non-zero if the first few bytes of the string starting at "s" and looking
no further than "e - 1" are well-formed UTF-8, as extended by Perl, that represents
some code point, subject to the restrictions given by "flags"; otherwise it evaluates
to 0. If non-zero, the value gives how many bytes starting at "s" comprise the code
point's representation. Any bytes remaining before "e", but beyond the ones needed to
form the first code point in "s", are not examined.
If "flags" is 0, this gives the same results as "isUTF8_CHAR"; if "flags" is
"UTF8_DISALLOW_ILLEGAL_INTERCHANGE", this gives the same results as
"isSTRICT_UTF8_CHAR"; and if "flags" is "UTF8_DISALLOW_ILLEGAL_C9_INTERCHANGE", this
gives the same results as "isC9_STRICT_UTF8_CHAR". Otherwise "flags" may be any
combination of the "UTF8_DISALLOW_foo" flags understood by "utf8n_to_uvchr", with the
same meanings.
The three alternative macros are for the most commonly needed validations; they are
likely to run somewhat faster than this more general one, as they can be inlined into
your code.
Use "is_utf8_string_flags", "is_utf8_string_loc_flags", and
"is_utf8_string_loclen_flags" to check entire strings.
Size_t isUTF8_CHAR_flags(const U8 * const s0, const U8 * const e,
const U32 flags)
"is_utf8_fixed_width_buf_flags"
Returns TRUE if the fixed-width buffer starting at "s" with length "len" is entirely
valid UTF-8, subject to the restrictions given by "flags"; otherwise it returns FALSE.
If "flags" is 0, any well-formed UTF-8, as extended by Perl, is accepted without
restriction. If the final few bytes of the buffer do not form a complete code point,
this will return TRUE anyway, provided that "is_utf8_valid_partial_char_flags" returns
TRUE for them.
If "flags" in non-zero, it can be any combination of the "UTF8_DISALLOW_foo" flags
accepted by "utf8n_to_uvchr", and with the same meanings.
This function differs from "is_utf8_string_flags" only in that the latter returns
FALSE if the final few bytes of the string don't form a complete code point.
bool is_utf8_fixed_width_buf_flags(const U8 * const s,
STRLEN len, const U32 flags)
"is_utf8_fixed_width_buf_loc_flags"
Like "is_utf8_fixed_width_buf_flags" but stores the location of the failure in the
"ep" pointer. If the function returns TRUE, *ep will point to the beginning of any
partial character at the end of the buffer; if there is no partial character *ep will
contain "s"+"len".
See also "is_utf8_fixed_width_buf_loclen_flags".
bool is_utf8_fixed_width_buf_loc_flags(const U8 * const s,
STRLEN len, const U8 **ep,
const U32 flags)
"is_utf8_fixed_width_buf_loclen_flags"
Like "is_utf8_fixed_width_buf_loc_flags" but stores the number of complete, valid
characters found in the "el" pointer.
bool is_utf8_fixed_width_buf_loclen_flags(const U8 * const s,
STRLEN len,
const U8 **ep,
STRLEN *el,
const U32 flags)
"is_utf8_invariant_string"
Returns TRUE if the first "len" bytes of the string "s" are the same regardless of the
UTF-8 encoding of the string (or UTF-EBCDIC encoding on EBCDIC machines); otherwise it
returns FALSE. That is, it returns TRUE if they are UTF-8 invariant. On ASCII-ish
machines, all the ASCII characters and only the ASCII characters fit this definition.
On EBCDIC machines, the ASCII-range characters are invariant, but so also are the C1
controls.
If "len" is 0, it will be calculated using strlen(s), (which means if you use this
option, that "s" can't have embedded "NUL" characters and has to have a terminating
"NUL" byte).
See also "is_utf8_string", "is_utf8_string_flags", "is_utf8_string_loc",
"is_utf8_string_loc_flags", "is_utf8_string_loclen", "is_utf8_string_loclen_flags",
"is_utf8_fixed_width_buf_flags", "is_utf8_fixed_width_buf_loc_flags",
"is_utf8_fixed_width_buf_loclen_flags", "is_strict_utf8_string",
"is_strict_utf8_string_loc", "is_strict_utf8_string_loclen",
"is_c9strict_utf8_string", "is_c9strict_utf8_string_loc", and
"is_c9strict_utf8_string_loclen".
bool is_utf8_invariant_string(const U8 * const s, STRLEN len)
"is_utf8_invariant_string_loc"
Like "is_utf8_invariant_string" but upon failure, stores the location of the first
UTF-8 variant character in the "ep" pointer; if all characters are UTF-8 invariant,
this function does not change the contents of *ep.
bool is_utf8_invariant_string_loc(const U8 * const s, STRLEN len,
const U8 **ep)
"is_utf8_string"
Returns TRUE if the first "len" bytes of string "s" form a valid Perl-extended-UTF-8
string; returns FALSE otherwise. If "len" is 0, it will be calculated using strlen(s)
(which means if you use this option, that "s" can't have embedded "NUL" characters and
has to have a terminating "NUL" byte). Note that all characters being ASCII
constitute 'a valid UTF-8 string'.
This function considers Perl's extended UTF-8 to be valid. That means that code
points above Unicode, surrogates, and non-character code points are considered valid
by this function. Use "is_strict_utf8_string", "is_c9strict_utf8_string", or
"is_utf8_string_flags" to restrict what code points are considered valid.
See also "is_utf8_invariant_string", "is_utf8_invariant_string_loc",
"is_utf8_string_loc", "is_utf8_string_loclen", "is_utf8_fixed_width_buf_flags",
"is_utf8_fixed_width_buf_loc_flags", "is_utf8_fixed_width_buf_loclen_flags",
bool is_utf8_string(const U8 *s, STRLEN len)
"is_utf8_string_flags"
Returns TRUE if the first "len" bytes of string "s" form a valid UTF-8 string, subject
to the restrictions imposed by "flags"; returns FALSE otherwise. If "len" is 0, it
will be calculated using strlen(s) (which means if you use this option, that "s" can't
have embedded "NUL" characters and has to have a terminating "NUL" byte). Note that
all characters being ASCII constitute 'a valid UTF-8 string'.
If "flags" is 0, this gives the same results as "is_utf8_string"; if "flags" is
"UTF8_DISALLOW_ILLEGAL_INTERCHANGE", this gives the same results as
"is_strict_utf8_string"; and if "flags" is "UTF8_DISALLOW_ILLEGAL_C9_INTERCHANGE",
this gives the same results as "is_c9strict_utf8_string". Otherwise "flags" may be
any combination of the "UTF8_DISALLOW_foo" flags understood by "utf8n_to_uvchr", with
the same meanings.
See also "is_utf8_invariant_string", "is_utf8_invariant_string_loc", "is_utf8_string",
"is_utf8_string_loc", "is_utf8_string_loc_flags", "is_utf8_string_loclen",
"is_utf8_string_loclen_flags", "is_utf8_fixed_width_buf_flags",
"is_utf8_fixed_width_buf_loc_flags", "is_utf8_fixed_width_buf_loclen_flags",
"is_strict_utf8_string", "is_strict_utf8_string_loc", "is_strict_utf8_string_loclen",
"is_c9strict_utf8_string", "is_c9strict_utf8_string_loc", and
"is_c9strict_utf8_string_loclen".
bool is_utf8_string_flags(const U8 *s, STRLEN len,
const U32 flags)
"is_utf8_string_loc"
Like "is_utf8_string" but stores the location of the failure (in the case of "utf8ness
failure") or the location "s"+"len" (in the case of "utf8ness success") in the "ep"
pointer.
See also "is_utf8_string_loclen".
bool is_utf8_string_loc(const U8 *s, const STRLEN len,
const U8 **ep)
"is_utf8_string_loc_flags"
Like "is_utf8_string_flags" but stores the location of the failure (in the case of
"utf8ness failure") or the location "s"+"len" (in the case of "utf8ness success") in
the "ep" pointer.
See also "is_utf8_string_loclen_flags".
bool is_utf8_string_loc_flags(const U8 *s, STRLEN len,
const U8 **ep, const U32 flags)
"is_utf8_string_loclen"
Like "is_utf8_string" but stores the location of the failure (in the case of "utf8ness
failure") or the location "s"+"len" (in the case of "utf8ness success") in the "ep"
pointer, and the number of UTF-8 encoded characters in the "el" pointer.
See also "is_utf8_string_loc".
bool is_utf8_string_loclen(const U8 *s, STRLEN len,
const U8 **ep, STRLEN *el)
"is_utf8_string_loclen_flags"
Like "is_utf8_string_flags" but stores the location of the failure (in the case of
"utf8ness failure") or the location "s"+"len" (in the case of "utf8ness success") in
the "ep" pointer, and the number of UTF-8 encoded characters in the "el" pointer.
See also "is_utf8_string_loc_flags".
bool is_utf8_string_loclen_flags(const U8 *s, STRLEN len,
const U8 **ep, STRLEN *el,
const U32 flags)
"is_utf8_valid_partial_char"
Returns 0 if the sequence of bytes starting at "s" and looking no further than "e - 1"
is the UTF-8 encoding, as extended by Perl, for one or more code points. Otherwise,
it returns 1 if there exists at least one non-empty sequence of bytes that when
appended to sequence "s", starting at position "e" causes the entire sequence to be
the well-formed UTF-8 of some code point; otherwise returns 0.
In other words this returns TRUE if "s" points to a partial UTF-8-encoded code point.
This is useful when a fixed-length buffer is being tested for being well-formed UTF-8,
but the final few bytes in it don't comprise a full character; that is, it is split
somewhere in the middle of the final code point's UTF-8 representation. (Presumably
when the buffer is refreshed with the next chunk of data, the new first bytes will
complete the partial code point.) This function is used to verify that the final
bytes in the current buffer are in fact the legal beginning of some code point, so
that if they aren't, the failure can be signalled without having to wait for the next
read.
bool is_utf8_valid_partial_char(const U8 * const s0,
const U8 * const e)
"is_utf8_valid_partial_char_flags"
Like "is_utf8_valid_partial_char", it returns a boolean giving whether or not the
input is a valid UTF-8 encoded partial character, but it takes an extra parameter,
"flags", which can further restrict which code points are considered valid.
If "flags" is 0, this behaves identically to "is_utf8_valid_partial_char". Otherwise
"flags" can be any combination of the "UTF8_DISALLOW_foo" flags accepted by
"utf8n_to_uvchr". If there is any sequence of bytes that can complete the input
partial character in such a way that a non-prohibited character is formed, the
function returns TRUE; otherwise FALSE. Non character code points cannot be
determined based on partial character input. But many of the other possible excluded
types can be determined from just the first one or two bytes.
bool is_utf8_valid_partial_char_flags(const U8 * const s0,
const U8 * const e,
const U32 flags)
"LATIN1_TO_NATIVE"
Returns the native equivalent of the input Latin-1 code point (including ASCII and
control characters) given by "ch". Thus, LATIN1_TO_NATIVE(66) on EBCDIC platforms
returns 194. These each represent the character "B" on their respective platforms.
On ASCII platforms no conversion is needed, so this macro expands to just its input,
adding no time nor space requirements to the implementation.
For conversion of code points potentially larger than will fit in a character, use
"UNI_TO_NATIVE".
U8 LATIN1_TO_NATIVE(U8 ch)
"NATIVE_TO_LATIN1"
Returns the Latin-1 (including ASCII and control characters) equivalent of the input
native code point given by "ch". Thus, NATIVE_TO_LATIN1(193) on EBCDIC platforms
returns 65. These each represent the character "A" on their respective platforms. On
ASCII platforms no conversion is needed, so this macro expands to just its input,
adding no time nor space requirements to the implementation.
For conversion of code points potentially larger than will fit in a character, use
"NATIVE_TO_UNI".
U8 NATIVE_TO_LATIN1(U8 ch)
"NATIVE_TO_UNI"
Returns the Unicode equivalent of the input native code point given by "ch". Thus,
NATIVE_TO_UNI(195) on EBCDIC platforms returns 67. These each represent the character
"C" on their respective platforms. On ASCII platforms no conversion is needed, so
this macro expands to just its input, adding no time nor space requirements to the
implementation.
UV NATIVE_TO_UNI(UV ch)
"pv_uni_display"
Build to the scalar "dsv" a displayable version of the UTF-8 encoded string "spv",
length "len", the displayable version being at most "pvlim" bytes long (if longer, the
rest is truncated and "..." will be appended).
The "flags" argument can have "UNI_DISPLAY_ISPRINT" set to display isPRINT()able
characters as themselves, "UNI_DISPLAY_BACKSLASH" to display the "\\[nrfta\\]" as the
backslashed versions (like "\n") ("UNI_DISPLAY_BACKSLASH" is preferred over
"UNI_DISPLAY_ISPRINT" for "\\"). "UNI_DISPLAY_QQ" (and its alias "UNI_DISPLAY_REGEX")
have both "UNI_DISPLAY_BACKSLASH" and "UNI_DISPLAY_ISPRINT" turned on.
Additionally, there is now "UNI_DISPLAY_BACKSPACE" which allows "\b" for a backspace,
but only when "UNI_DISPLAY_BACKSLASH" also is set.
The pointer to the PV of the "dsv" is returned.
See also "sv_uni_display".
char * pv_uni_display(SV *dsv, const U8 *spv, STRLEN len,
STRLEN pvlim, UV flags)
"REPLACEMENT_CHARACTER_UTF8"
This is a macro that evaluates to a string constant of the UTF-8 bytes that define
the Unicode REPLACEMENT CHARACTER (U+FFFD) for the platform that perl is compiled on.
This allows code to use a mnemonic for this character that works on both ASCII and
EBCDIC platforms. "sizeof(REPLACEMENT_CHARACTER_UTF8) - 1" can be used to get its
length in bytes.
"sv_cat_decode"
"encoding" is assumed to be an "Encode" object, the PV of "ssv" is assumed to be
octets in that encoding and decoding the input starts from the position which
"(PV + *offset)" pointed to. "dsv" will be concatenated with the decoded UTF-8 string
from "ssv". Decoding will terminate when the string "tstr" appears in decoding output
or the input ends on the PV of "ssv". The value which "offset" points will be
modified to the last input position on "ssv".
Returns TRUE if the terminator was found, else returns FALSE.
bool sv_cat_decode(SV *dsv, SV *encoding, SV *ssv, int *offset,
char *tstr, int tlen)
"sv_recode_to_utf8"
"encoding" is assumed to be an "Encode" object, on entry the PV of "sv" is assumed to
be octets in that encoding, and "sv" will be converted into Unicode (and UTF-8).
If "sv" already is UTF-8 (or if it is not "POK"), or if "encoding" is not a reference,
nothing is done to "sv". If "encoding" is not an "Encode::XS" Encoding object, bad
things will happen. (See encoding and Encode.)
The PV of "sv" is returned.
char * sv_recode_to_utf8(SV *sv, SV *encoding)
"sv_uni_display"
Build to the scalar "dsv" a displayable version of the scalar "sv", the displayable
version being at most "pvlim" bytes long (if longer, the rest is truncated and "..."
will be appended).
The "flags" argument is as in "pv_uni_display"().
The pointer to the PV of the "dsv" is returned.
char * sv_uni_display(SV *dsv, SV *ssv, STRLEN pvlim, UV flags)
"UNICODE_IS_NONCHAR"
Returns a boolean as to whether or not "uv" is one of the Unicode non-character code
points
bool UNICODE_IS_NONCHAR(const UV uv)
"UNICODE_IS_REPLACEMENT"
Returns a boolean as to whether or not "uv" is the Unicode REPLACEMENT CHARACTER
bool UNICODE_IS_REPLACEMENT(const UV uv)
"UNICODE_IS_SUPER"
Returns a boolean as to whether or not "uv" is above the maximum legal Unicode code
point of U+10FFFF.
bool UNICODE_IS_SUPER(const UV uv)
"UNICODE_IS_SURROGATE"
Returns a boolean as to whether or not "uv" is one of the Unicode surrogate code
points
bool UNICODE_IS_SURROGATE(const UV uv)
"UNICODE_REPLACEMENT"
Evaluates to 0xFFFD, the code point of the Unicode REPLACEMENT CHARACTER
"UNI_TO_NATIVE"
Returns the native equivalent of the input Unicode code point given by "ch". Thus,
UNI_TO_NATIVE(68) on EBCDIC platforms returns 196. These each represent the character
"D" on their respective platforms. On ASCII platforms no conversion is needed, so
this macro expands to just its input, adding no time nor space requirements to the
implementation.
UV UNI_TO_NATIVE(UV ch)
"UTF8_CHK_SKIP"
This is a safer version of "UTF8SKIP", but still not as safe as "UTF8_SAFE_SKIP".
This version doesn't blindly assume that the input string pointed to by "s" is well-
formed, but verifies that there isn't a NUL terminating character before the expected
end of the next character in "s". The length "UTF8_CHK_SKIP" returns stops just
before any such NUL.
Perl tends to add NULs, as an insurance policy, after the end of strings in SV's, so
it is likely that using this macro will prevent inadvertent reading beyond the end of
the input buffer, even if it is malformed UTF-8.
This macro is intended to be used by XS modules where the inputs could be malformed,
and it isn't feasible to restructure to use the safer "UTF8_SAFE_SKIP", for example
when interfacing with a C library.
STRLEN UTF8_CHK_SKIP(char* s)
"utf8_distance"
Returns the number of UTF-8 characters between the UTF-8 pointers "a" and "b".
WARNING: use only if you *know* that the pointers point inside the same UTF-8 buffer.
IV utf8_distance(const U8 *a, const U8 *b)
"utf8_hop"
Return the UTF-8 pointer "s" displaced by "off" characters, either forward (if "off"
is positive) or backward (if negative). "s" does not need to be pointing to the
starting byte of a character. If it isn't, one count of "off" will be used up to get
to the start of the next character for forward hops, and to the start of the current
character for negative ones.
WARNING: Prefer "utf8_hop_safe" to this one.
Do NOT use this function unless you know "off" is within the UTF-8 data pointed to by
"s" and that on entry "s" is aligned on the first byte of a character or just after
the last byte of a character.
U8 * utf8_hop(const U8 *s, SSize_t off)
"utf8_hop_back"
Return the UTF-8 pointer "s" displaced by up to "off" characters, backward. "s" does
not need to be pointing to the starting byte of a character. If it isn't, one count
of "off" will be used up to get to that start.
"off" must be non-positive.
"s" must be after or equal to "start".
When moving backward it will not move before "start".
Will not exceed this limit even if the string is not valid "UTF-8".
U8 * utf8_hop_back(const U8 *s, SSize_t off, const U8 *start)
"utf8_hop_forward"
Return the UTF-8 pointer "s" displaced by up to "off" characters, forward. "s" does
not need to be pointing to the starting byte of a character. If it isn't, one count
of "off" will be used up to get to the start of the next character.
"off" must be non-negative.
"s" must be before or equal to "end".
When moving forward it will not move beyond "end".
Will not exceed this limit even if the string is not valid "UTF-8".
U8 * utf8_hop_forward(const U8 *s, SSize_t off, const U8 *end)
"utf8_hop_safe"
Return the UTF-8 pointer "s" displaced by up to "off" characters, either forward or
backward. "s" does not need to be pointing to the starting byte of a character. If
it isn't, one count of "off" will be used up to get to the start of the next character
for forward hops, and to the start of the current character for negative ones.
When moving backward it will not move before "start".
When moving forward it will not move beyond "end".
Will not exceed those limits even if the string is not valid "UTF-8".
U8 * utf8_hop_safe(const U8 *s, SSize_t off, const U8 *start,
const U8 *end)
"UTF8_IS_INVARIANT"
Evaluates to 1 if the byte "c" represents the same character when encoded in UTF-8 as
when not; otherwise evaluates to 0. UTF-8 invariant characters can be copied as-is
when converting to/from UTF-8, saving time.
In spite of the name, this macro gives the correct result if the input string from
which "c" comes is not encoded in UTF-8.
See "UVCHR_IS_INVARIANT" for checking if a UV is invariant.
bool UTF8_IS_INVARIANT(char c)
"UTF8_IS_NONCHAR"
Evaluates to non-zero if the first few bytes of the string starting at "s" and looking
no further than "e - 1" are well-formed UTF-8 that represents one of the Unicode non-
character code points; otherwise it evaluates to 0. If non-zero, the value gives how
many bytes starting at "s" comprise the code point's representation.
bool UTF8_IS_NONCHAR(const U8 *s, const U8 *e)
"UTF8_IS_REPLACEMENT"
Evaluates to non-zero if the first few bytes of the string starting at "s" and looking
no further than "e - 1" are well-formed UTF-8 that represents the Unicode REPLACEMENT
CHARACTER; otherwise it evaluates to 0. If non-zero, the value gives how many bytes
starting at "s" comprise the code point's representation.
bool UTF8_IS_REPLACEMENT(const U8 *s, const U8 *e)
"UTF8_IS_SUPER"
Recall that Perl recognizes an extension to UTF-8 that can encode code points larger
than the ones defined by Unicode, which are 0..0x10FFFF.
This macro evaluates to non-zero if the first few bytes of the string starting at "s"
and looking no further than "e - 1" are from this UTF-8 extension; otherwise it
evaluates to 0. If non-zero, the return is how many bytes starting at "s" comprise
the code point's representation.
0 is returned if the bytes are not well-formed extended UTF-8, or if they represent a
code point that cannot fit in a UV on the current platform. Hence this macro can give
different results when run on a 64-bit word machine than on one with a 32-bit word
size.
Note that it is illegal in Perl to have code points that are larger than what can fit
in an IV on the current machine; and illegal in Unicode to have any that this macro
matches
bool UTF8_IS_SUPER(const U8 *s, const U8 *e)
"UTF8_IS_SURROGATE"
Evaluates to non-zero if the first few bytes of the string starting at "s" and looking
no further than "e - 1" are well-formed UTF-8 that represents one of the Unicode
surrogate code points; otherwise it evaluates to 0. If non-zero, the value gives how
many bytes starting at "s" comprise the code point's representation.
bool UTF8_IS_SURROGATE(const U8 *s, const U8 *e)
"utf8_length"
Returns the number of characters in the sequence of UTF-8-encoded bytes starting at
"s" and ending at the byte just before "e". If <s> and <e> point to the same place,
it returns 0 with no warning raised.
If "e < s" or if the scan would end up past "e", it raises a UTF8 warning and returns
the number of valid characters.
STRLEN utf8_length(const U8 *s0, const U8 *e)
"UTF8_MAXBYTES"
The maximum width of a single UTF-8 encoded character, in bytes.
NOTE: Strictly speaking Perl's UTF-8 should not be called UTF-8 since UTF-8 is an
encoding of Unicode, and Unicode's upper limit, 0x10FFFF, can be expressed with 4
bytes. However, Perl thinks of UTF-8 as a way to encode non-negative integers in a
binary format, even those above Unicode.
"UTF8_MAXBYTES_CASE"
The maximum number of UTF-8 bytes a single Unicode character can
uppercase/lowercase/titlecase/fold into.
"utf8ness_t"
This typedef is used by several core functions that return PV strings, to indicate the
UTF-8ness of those strings.
(If you write a new function, you probably should instead return the PV in an SV with
the UTF-8 flag of the SV properly set, rather than use this mechanism.)
The possible values this can be are:
"UTF8NESS_YES"
This means the string definitely should be treated as a sequence of UTF-8-encoded
characters.
Most code that needs to handle this typedef should be of the form:
if (utf8ness_flag == UTF8NESS_YES) {
treat as utf8; // like turning on an SV UTF-8 flag
}
"UTF8NESS_NO"
This means the string definitely should be treated as a sequence of bytes, not
encoded as UTF-8.
"UTF8NESS_IMMATERIAL"
This means it is equally valid to treat the string as bytes, or as UTF-8
characters; use whichever way you want. This happens when the string consists
entirely of characters which have the same representation whether encoded in UTF-8
or not.
"UTF8NESS_UNKNOWN"
This means it is unknown how the string should be treated. No core function will
ever return this value to a non-core caller. Instead, it is used by the caller to
initialize a variable to a non-legal value. A typical call will look like:
utf8ness_t string_is_utf8 = UTF8NESS_UNKNOWN
const char * string = foo(arg1, arg2, ..., &string_is_utf8);
if (string_is_utf8 == UTF8NESS_YES) {
do something for UTF-8;
}
The following relationships hold between the enum values:
"0 <= enum value <= UTF8NESS_IMMATERIAL"
the string may be treated in code as non-UTF8
"UTF8NESS_IMMATERIAL <= <enum value"
the string may be treated in code as encoded in UTF-8
"utf8n_to_uvchr"
THIS FUNCTION SHOULD BE USED IN ONLY VERY SPECIALIZED CIRCUMSTANCES. Most code should
use "utf8_to_uvchr_buf"() rather than call this directly.
Bottom level UTF-8 decode routine. Returns the native code point value of the first
character in the string "s", which is assumed to be in UTF-8 (or UTF-EBCDIC) encoding,
and no longer than "curlen" bytes; *retlen (if "retlen" isn't NULL) will be set to the
length, in bytes, of that character.
The value of "flags" determines the behavior when "s" does not point to a well-formed
UTF-8 character. If "flags" is 0, encountering a malformation causes zero to be
returned and *retlen is set so that ("s" + *retlen) is the next possible position in
"s" that could begin a non-malformed character. Also, if UTF-8 warnings haven't been
lexically disabled, a warning is raised. Some UTF-8 input sequences may contain
multiple malformations. This function tries to find every possible one in each call,
so multiple warnings can be raised for the same sequence.
Various ALLOW flags can be set in "flags" to allow (and not warn on) individual types
of malformations, such as the sequence being overlong (that is, when there is a
shorter sequence that can express the same code point; overlong sequences are
expressly forbidden in the UTF-8 standard due to potential security issues). Another
malformation example is the first byte of a character not being a legal first byte.
See utf8.h for the list of such flags. Even if allowed, this function generally
returns the Unicode REPLACEMENT CHARACTER when it encounters a malformation. There
are flags in utf8.h to override this behavior for the overlong malformations, but
don't do that except for very specialized purposes.
The "UTF8_CHECK_ONLY" flag overrides the behavior when a non-allowed (by other flags)
malformation is found. If this flag is set, the routine assumes that the caller will
raise a warning, and this function will silently just set "retlen" to -1 (cast to
"STRLEN") and return zero.
Note that this API requires disambiguation between successful decoding a "NUL"
character, and an error return (unless the "UTF8_CHECK_ONLY" flag is set), as in both
cases, 0 is returned, and, depending on the malformation, "retlen" may be set to 1.
To disambiguate, upon a zero return, see if the first byte of "s" is 0 as well. If
so, the input was a "NUL"; if not, the input had an error. Or you can use
"utf8n_to_uvchr_error".
Certain code points are considered problematic. These are Unicode surrogates, Unicode
non-characters, and code points above the Unicode maximum of 0x10FFFF. By default
these are considered regular code points, but certain situations warrant special
handling for them, which can be specified using the "flags" parameter. If "flags"
contains "UTF8_DISALLOW_ILLEGAL_INTERCHANGE", all three classes are treated as
malformations and handled as such. The flags "UTF8_DISALLOW_SURROGATE",
"UTF8_DISALLOW_NONCHAR", and "UTF8_DISALLOW_SUPER" (meaning above the legal Unicode
maximum) can be set to disallow these categories individually.
"UTF8_DISALLOW_ILLEGAL_INTERCHANGE" restricts the allowed inputs to the strict UTF-8
traditionally defined by Unicode. Use "UTF8_DISALLOW_ILLEGAL_C9_INTERCHANGE" to use
the strictness definition given by Unicode Corrigendum #9
<https://www.unicode.org/versions/corrigendum9.html>. The difference between
traditional strictness and C9 strictness is that the latter does not forbid non-
character code points. (They are still discouraged, however.) For more discussion
see "Noncharacter code points" in perlunicode.
The flags "UTF8_WARN_ILLEGAL_INTERCHANGE", "UTF8_WARN_ILLEGAL_C9_INTERCHANGE",
"UTF8_WARN_SURROGATE", "UTF8_WARN_NONCHAR", and "UTF8_WARN_SUPER" will cause warning
messages to be raised for their respective categories, but otherwise the code points
are considered valid (not malformations). To get a category to both be treated as a
malformation and raise a warning, specify both the WARN and DISALLOW flags. (But note
that warnings are not raised if lexically disabled nor if "UTF8_CHECK_ONLY" is also
specified.)
Extremely high code points were never specified in any standard, and require an
extension to UTF-8 to express, which Perl does. It is likely that programs written in
something other than Perl would not be able to read files that contain these; nor
would Perl understand files written by something that uses a different extension. For
these reasons, there is a separate set of flags that can warn and/or disallow these
extremely high code points, even if other above-Unicode ones are accepted. They are
the "UTF8_WARN_PERL_EXTENDED" and "UTF8_DISALLOW_PERL_EXTENDED" flags. For more
information see "UTF8_GOT_PERL_EXTENDED". Of course "UTF8_DISALLOW_SUPER" will treat
all above-Unicode code points, including these, as malformations. (Note that the
Unicode standard considers anything above 0x10FFFF to be illegal, but there are
standards predating it that allow up to 0x7FFF_FFFF (2**31 -1))
A somewhat misleadingly named synonym for "UTF8_WARN_PERL_EXTENDED" is retained for
backward compatibility: "UTF8_WARN_ABOVE_31_BIT". Similarly,
"UTF8_DISALLOW_ABOVE_31_BIT" is usable instead of the more accurately named
"UTF8_DISALLOW_PERL_EXTENDED". The names are misleading because these flags can apply
to code points that actually do fit in 31 bits. This happens on EBCDIC platforms, and
sometimes when the overlong malformation is also present. The new names accurately
describe the situation in all cases.
All other code points corresponding to Unicode characters, including private use and
those yet to be assigned, are never considered malformed and never warn.
UV utf8n_to_uvchr(const U8 *s, STRLEN curlen, STRLEN *retlen,
const U32 flags)
"utf8n_to_uvchr_error"
THIS FUNCTION SHOULD BE USED IN ONLY VERY SPECIALIZED CIRCUMSTANCES. Most code should
use "utf8_to_uvchr_buf"() rather than call this directly.
This function is for code that needs to know what the precise malformation(s) are when
an error is found. If you also need to know the generated warning messages, use
"utf8n_to_uvchr_msgs"() instead.
It is like "utf8n_to_uvchr" but it takes an extra parameter placed after all the
others, "errors". If this parameter is 0, this function behaves identically to
"utf8n_to_uvchr". Otherwise, "errors" should be a pointer to a "U32" variable, which
this function sets to indicate any errors found. Upon return, if *errors is 0, there
were no errors found. Otherwise, *errors is the bit-wise "OR" of the bits described
in the list below. Some of these bits will be set if a malformation is found, even if
the input "flags" parameter indicates that the given malformation is allowed; those
exceptions are noted:
"UTF8_GOT_PERL_EXTENDED"
The input sequence is not standard UTF-8, but a Perl extension. This bit is set
only if the input "flags" parameter contains either the
"UTF8_DISALLOW_PERL_EXTENDED" or the "UTF8_WARN_PERL_EXTENDED" flags.
Code points above 0x7FFF_FFFF (2**31 - 1) were never specified in any standard,
and so some extension must be used to express them. Perl uses a natural extension
to UTF-8 to represent the ones up to 2**36-1, and invented a further extension to
represent even higher ones, so that any code point that fits in a 64-bit word can
be represented. Text using these extensions is not likely to be portable to non-
Perl code. We lump both of these extensions together and refer to them as Perl
extended UTF-8. There exist other extensions that people have invented,
incompatible with Perl's.
On EBCDIC platforms starting in Perl v5.24, the Perl extension for representing
extremely high code points kicks in at 0x3FFF_FFFF (2**30 -1), which is lower than
on ASCII. Prior to that, code points 2**31 and higher were simply
unrepresentable, and a different, incompatible method was used to represent code
points between 2**30 and 2**31 - 1.
On both platforms, ASCII and EBCDIC, "UTF8_GOT_PERL_EXTENDED" is set if Perl
extended UTF-8 is used.
In earlier Perls, this bit was named "UTF8_GOT_ABOVE_31_BIT", which you still may
use for backward compatibility. That name is misleading, as this flag may be set
when the code point actually does fit in 31 bits. This happens on EBCDIC
platforms, and sometimes when the overlong malformation is also present. The new
name accurately describes the situation in all cases.
"UTF8_GOT_CONTINUATION"
The input sequence was malformed in that the first byte was a UTF-8 continuation
byte.
"UTF8_GOT_EMPTY"
The input "curlen" parameter was 0.
"UTF8_GOT_LONG"
The input sequence was malformed in that there is some other sequence that
evaluates to the same code point, but that sequence is shorter than this one.
Until Unicode 3.1, it was legal for programs to accept this malformation, but it
was discovered that this created security issues.
"UTF8_GOT_NONCHAR"
The code point represented by the input UTF-8 sequence is for a Unicode non-
character code point. This bit is set only if the input "flags" parameter
contains either the "UTF8_DISALLOW_NONCHAR" or the "UTF8_WARN_NONCHAR" flags.
"UTF8_GOT_NON_CONTINUATION"
The input sequence was malformed in that a non-continuation type byte was found in
a position where only a continuation type one should be. See also
"UTF8_GOT_SHORT".
"UTF8_GOT_OVERFLOW"
The input sequence was malformed in that it is for a code point that is not
representable in the number of bits available in an IV on the current platform.
"UTF8_GOT_SHORT"
The input sequence was malformed in that "curlen" is smaller than required for a
complete sequence. In other words, the input is for a partial character sequence.
"UTF8_GOT_SHORT" and "UTF8_GOT_NON_CONTINUATION" both indicate a too short
sequence. The difference is that "UTF8_GOT_NON_CONTINUATION" indicates always
that there is an error, while "UTF8_GOT_SHORT" means that an incomplete sequence
was looked at. If no other flags are present, it means that the sequence was
valid as far as it went. Depending on the application, this could mean one of
three things:
• The "curlen" length parameter passed in was too small, and the function was
prevented from examining all the necessary bytes.
• The buffer being looked at is based on reading data, and the data received so
far stopped in the middle of a character, so that the next read will read the
remainder of this character. (It is up to the caller to deal with the split
bytes somehow.)
• This is a real error, and the partial sequence is all we're going to get.
"UTF8_GOT_SUPER"
The input sequence was malformed in that it is for a non-Unicode code point; that
is, one above the legal Unicode maximum. This bit is set only if the input
"flags" parameter contains either the "UTF8_DISALLOW_SUPER" or the
"UTF8_WARN_SUPER" flags.
"UTF8_GOT_SURROGATE"
The input sequence was malformed in that it is for a -Unicode UTF-16 surrogate
code point. This bit is set only if the input "flags" parameter contains either
the "UTF8_DISALLOW_SURROGATE" or the "UTF8_WARN_SURROGATE" flags.
To do your own error handling, call this function with the "UTF8_CHECK_ONLY" flag to
suppress any warnings, and then examine the *errors return.
UV utf8n_to_uvchr_error(const U8 *s, STRLEN curlen,
STRLEN *retlen, const U32 flags,
U32 *errors)
"utf8n_to_uvchr_msgs"
THIS FUNCTION SHOULD BE USED IN ONLY VERY SPECIALIZED CIRCUMSTANCES. Most code should
use "utf8_to_uvchr_buf"() rather than call this directly.
This function is for code that needs to know what the precise malformation(s) are when
an error is found, and wants the corresponding warning and/or error messages to be
returned to the caller rather than be displayed. All messages that would have been
displayed if all lexical warnings are enabled will be returned.
It is just like "utf8n_to_uvchr_error" but it takes an extra parameter placed after
all the others, "msgs". If this parameter is 0, this function behaves identically to
"utf8n_to_uvchr_error". Otherwise, "msgs" should be a pointer to an "AV *" variable,
in which this function creates a new AV to contain any appropriate messages. The
elements of the array are ordered so that the first message that would have been
displayed is in the 0th element, and so on. Each element is a hash with three key-
value pairs, as follows:
"text"
The text of the message as a "SVpv".
"warn_categories"
The warning category (or categories) packed into a "SVuv".
"flag"
A single flag bit associated with this message, in a "SVuv". The bit corresponds
to some bit in the *errors return value, such as "UTF8_GOT_LONG".
It's important to note that specifying this parameter as non-null will cause any
warnings this function would otherwise generate to be suppressed, and instead be
placed in *msgs. The caller can check the lexical warnings state (or not) when
choosing what to do with the returned messages.
If the flag "UTF8_CHECK_ONLY" is passed, no warnings are generated, and hence no AV is
created.
The caller, of course, is responsible for freeing any returned AV.
UV utf8n_to_uvchr_msgs(const U8 *s, STRLEN curlen,
STRLEN *retlen, const U32 flags,
U32 *errors, AV **msgs)
"UTF8_SAFE_SKIP"
returns 0 if "s >= e"; otherwise returns the number of bytes in the UTF-8 encoded
character whose first byte is pointed to by "s". But it never returns beyond "e".
On DEBUGGING builds, it asserts that "s <= e".
STRLEN UTF8_SAFE_SKIP(char* s, char* e)
"UTF8SKIP"
returns the number of bytes a non-malformed UTF-8 encoded character whose first
(perhaps only) byte is pointed to by "s".
If there is a possibility of malformed input, use instead:
"UTF8_SAFE_SKIP" if you know the maximum ending pointer in the buffer pointed to by
"s"; or
"UTF8_CHK_SKIP" if you don't know it.
It is better to restructure your code so the end pointer is passed down so that you
know what it actually is at the point of this call, but if that isn't possible,
"UTF8_CHK_SKIP" can minimize the chance of accessing beyond the end of the input
buffer.
STRLEN UTF8SKIP(char* s)
"UTF8_SKIP"
This is a synonym for "UTF8SKIP"
STRLEN UTF8_SKIP(char* s)
"utf8_to_bytes"
NOTE: "utf8_to_bytes" is experimental and may change or be removed without notice.
Converts a string "s" of length *lenp from UTF-8 into native byte encoding. Unlike
"bytes_to_utf8", this over-writes the original string, and updates *lenp to contain
the new length. Returns zero on failure (leaving "s" unchanged) setting *lenp to -1.
Upon successful return, the number of variants in the string can be computed by having
saved the value of *lenp before the call, and subtracting the after-call value of
*lenp from it.
If you need a copy of the string, see "bytes_from_utf8".
U8 * utf8_to_bytes(U8 *s, STRLEN *lenp)
"utf8_to_uvchr"
"DEPRECATED!" It is planned to remove "utf8_to_uvchr" from a future release of Perl.
Do not use it for new code; remove it from existing code.
Returns the native code point of the first character in the string "s" which is
assumed to be in UTF-8 encoding; "retlen" will be set to the length, in bytes, of that
character.
Some, but not all, UTF-8 malformations are detected, and in fact, some malformed input
could cause reading beyond the end of the input buffer, which is why this function is
deprecated. Use "utf8_to_uvchr_buf" instead.
If "s" points to one of the detected malformations, and UTF8 warnings are enabled,
zero is returned and *retlen is set (if "retlen" isn't "NULL") to -1. If those
warnings are off, the computed value if well-defined (or the Unicode REPLACEMENT
CHARACTER, if not) is silently returned, and *retlen is set (if "retlen" isn't NULL)
so that ("s" + *retlen) is the next possible position in "s" that could begin a non-
malformed character. See "utf8n_to_uvchr" for details on when the REPLACEMENT
CHARACTER is returned.
UV utf8_to_uvchr(const U8 *s, STRLEN *retlen)
"utf8_to_uvchr_buf"
Returns the native code point of the first character in the string "s" which is
assumed to be in UTF-8 encoding; "send" points to 1 beyond the end of "s". *retlen
will be set to the length, in bytes, of that character.
If "s" does not point to a well-formed UTF-8 character and UTF8 warnings are enabled,
zero is returned and *retlen is set (if "retlen" isn't "NULL") to -1. If those
warnings are off, the computed value, if well-defined (or the Unicode REPLACEMENT
CHARACTER if not), is silently returned, and *retlen is set (if "retlen" isn't "NULL")
so that ("s" + *retlen) is the next possible position in "s" that could begin a non-
malformed character. See "utf8n_to_uvchr" for details on when the REPLACEMENT
CHARACTER is returned.
UV utf8_to_uvchr_buf(const U8 *s, const U8 *send, STRLEN *retlen)
"UVCHR_IS_INVARIANT"
Evaluates to 1 if the representation of code point "cp" is the same whether or not it
is encoded in UTF-8; otherwise evaluates to 0. UTF-8 invariant characters can be
copied as-is when converting to/from UTF-8, saving time. "cp" is Unicode if above
255; otherwise is platform-native.
bool UVCHR_IS_INVARIANT(UV cp)
"UVCHR_SKIP"
returns the number of bytes required to represent the code point "cp" when encoded as
UTF-8. "cp" is a native (ASCII or EBCDIC) code point if less than 255; a Unicode code
point otherwise.
STRLEN UVCHR_SKIP(UV cp)
"uvchr_to_utf8_flags"
Adds the UTF-8 representation of the native code point "uv" to the end of the string
"d"; "d" should have at least "UVCHR_SKIP(uv)+1" (up to "UTF8_MAXBYTES+1") free bytes
available. The return value is the pointer to the byte after the end of the new
character. In other words,
d = uvchr_to_utf8_flags(d, uv, flags);
or, in most cases,
d = uvchr_to_utf8_flags(d, uv, 0);
This is the Unicode-aware way of saying
*(d++) = uv;
If "flags" is 0, this function accepts any code point from 0.."IV_MAX" as input.
"IV_MAX" is typically 0x7FFF_FFFF in a 32-bit word.
Specifying "flags" can further restrict what is allowed and not warned on, as follows:
If "uv" is a Unicode surrogate code point and "UNICODE_WARN_SURROGATE" is set, the
function will raise a warning, provided UTF8 warnings are enabled. If instead
"UNICODE_DISALLOW_SURROGATE" is set, the function will fail and return NULL. If both
flags are set, the function will both warn and return NULL.
Similarly, the "UNICODE_WARN_NONCHAR" and "UNICODE_DISALLOW_NONCHAR" flags affect how
the function handles a Unicode non-character.
And likewise, the "UNICODE_WARN_SUPER" and "UNICODE_DISALLOW_SUPER" flags affect the
handling of code points that are above the Unicode maximum of 0x10FFFF. Languages
other than Perl may not be able to accept files that contain these.
The flag "UNICODE_WARN_ILLEGAL_INTERCHANGE" selects all three of the above WARN flags;
and "UNICODE_DISALLOW_ILLEGAL_INTERCHANGE" selects all three DISALLOW flags.
"UNICODE_DISALLOW_ILLEGAL_INTERCHANGE" restricts the allowed inputs to the strict
UTF-8 traditionally defined by Unicode. Similarly,
"UNICODE_WARN_ILLEGAL_C9_INTERCHANGE" and "UNICODE_DISALLOW_ILLEGAL_C9_INTERCHANGE"
are shortcuts to select the above-Unicode and surrogate flags, but not the non-
character ones, as defined in Unicode Corrigendum #9
<https://www.unicode.org/versions/corrigendum9.html>. See "Noncharacter code points"
in perlunicode.
Extremely high code points were never specified in any standard, and require an
extension to UTF-8 to express, which Perl does. It is likely that programs written in
something other than Perl would not be able to read files that contain these; nor
would Perl understand files written by something that uses a different extension. For
these reasons, there is a separate set of flags that can warn and/or disallow these
extremely high code points, even if other above-Unicode ones are accepted. They are
the "UNICODE_WARN_PERL_EXTENDED" and "UNICODE_DISALLOW_PERL_EXTENDED" flags. For more
information see "UTF8_GOT_PERL_EXTENDED". Of course "UNICODE_DISALLOW_SUPER" will
treat all above-Unicode code points, including these, as malformations. (Note that
the Unicode standard considers anything above 0x10FFFF to be illegal, but there are
standards predating it that allow up to 0x7FFF_FFFF (2**31 -1))
A somewhat misleadingly named synonym for "UNICODE_WARN_PERL_EXTENDED" is retained for
backward compatibility: "UNICODE_WARN_ABOVE_31_BIT". Similarly,
"UNICODE_DISALLOW_ABOVE_31_BIT" is usable instead of the more accurately named
"UNICODE_DISALLOW_PERL_EXTENDED". The names are misleading because on EBCDIC
platforms,these flags can apply to code points that actually do fit in 31 bits. The
new names accurately describe the situation in all cases.
U8 * uvchr_to_utf8_flags(U8 *d, UV uv, UV flags)
"uvchr_to_utf8_flags_msgs"
THIS FUNCTION SHOULD BE USED IN ONLY VERY SPECIALIZED CIRCUMSTANCES.
Most code should use ""uvchr_to_utf8_flags"()" rather than call this directly.
This function is for code that wants any warning and/or error messages to be returned
to the caller rather than be displayed. All messages that would have been displayed
if all lexical warnings are enabled will be returned.
It is just like "uvchr_to_utf8_flags" but it takes an extra parameter placed after all
the others, "msgs". If this parameter is 0, this function behaves identically to
"uvchr_to_utf8_flags". Otherwise, "msgs" should be a pointer to an "HV *" variable,
in which this function creates a new HV to contain any appropriate messages. The hash
has three key-value pairs, as follows:
"text"
The text of the message as a "SVpv".
"warn_categories"
The warning category (or categories) packed into a "SVuv".
"flag"
A single flag bit associated with this message, in a "SVuv". The bit corresponds
to some bit in the *errors return value, such as "UNICODE_GOT_SURROGATE".
It's important to note that specifying this parameter as non-null will cause any
warnings this function would otherwise generate to be suppressed, and instead be
placed in *msgs. The caller can check the lexical warnings state (or not) when
choosing what to do with the returned messages.
The caller, of course, is responsible for freeing any returned HV.
U8 * uvchr_to_utf8_flags_msgs(U8 *d, UV uv, UV flags, HV **msgs)
"uvchr_to_utf8"
Adds the UTF-8 representation of the native code point "uv" to the end of the string
"d"; "d" should have at least "UVCHR_SKIP(uv)+1" (up to "UTF8_MAXBYTES+1") free bytes
available. The return value is the pointer to the byte after the end of the new
character. In other words,
d = uvchr_to_utf8(d, uv);
is the recommended wide native character-aware way of saying
*(d++) = uv;
This function accepts any code point from 0.."IV_MAX" as input. "IV_MAX" is typically
0x7FFF_FFFF in a 32-bit word.
It is possible to forbid or warn on non-Unicode code points, or those that may be
problematic by using "uvchr_to_utf8_flags".
U8 * uvchr_to_utf8(U8 *d, UV uv)
Utility Functions
"C_ARRAY_END"
Returns a pointer to one element past the final element of the input C array.
void * C_ARRAY_END(void *a)
"C_ARRAY_LENGTH"
Returns the number of elements in the input C array (so you want your zero-based
indices to be less than but not equal to).
STRLEN C_ARRAY_LENGTH(void *a)
"getcwd_sv"
Fill "sv" with current working directory
int getcwd_sv(SV *sv)
"IN_PERL_COMPILETIME"
Returns 1 if this macro is being called during the compilation phase of the program;
otherwise 0;
bool IN_PERL_COMPILETIME
"IN_PERL_RUNTIME"
Returns 1 if this macro is being called during the execution phase of the program;
otherwise 0;
bool IN_PERL_RUNTIME
"IS_SAFE_SYSCALL"
Same as "is_safe_syscall".
bool IS_SAFE_SYSCALL(NN const char *pv, STRLEN len,
NN const char *what, NN const char *op_name)
"is_safe_syscall"
Test that the given "pv" (with length "len") doesn't contain any internal "NUL"
characters. If it does, set "errno" to "ENOENT", optionally warn using the "syscalls"
category, and return FALSE.
Return TRUE if the name is safe.
"what" and "op_name" are used in any warning.
Used by the IS_SAFE_SYSCALL() macro.
bool is_safe_syscall(const char *pv, STRLEN len,
const char *what, const char *op_name)
"my_setenv"
A wrapper for the C library setenv(3). Don't use the latter, as the perl version has
desirable safeguards
void my_setenv(const char *nam, const char *val)
"newPADxVOP"
Constructs, checks and returns an op containing a pad offset. "type" is the opcode,
which should be one of "OP_PADSV", "OP_PADAV", "OP_PADHV" or "OP_PADCV". The returned
op will have the "op_targ" field set by the "padix" argument.
This is convenient when constructing a large optree in nested function calls, as it
avoids needing to store the pad op directly to set the "op_targ" field as a side-
effect. For example
o = op_append_elem(OP_LINESEQ, o,
newPADxVOP(OP_PADSV, 0, padix));
OP * newPADxVOP(I32 type, I32 flags, PADOFFSET padix)
"phase_name"
Returns the given phase's name as a NUL-terminated string.
For example, to print a stack trace that includes the current interpreter phase you
might do:
const char* phase_name = phase_name(PL_phase);
mess("This is weird. (Perl phase: %s)", phase_name);
const char * const phase_name(enum perl_phase)
"Poison"
PoisonWith(0xEF) for catching access to freed memory.
void Poison(void* dest, int nitems, type)
"PoisonFree"
PoisonWith(0xEF) for catching access to freed memory.
void PoisonFree(void* dest, int nitems, type)
"PoisonNew"
PoisonWith(0xAB) for catching access to allocated but uninitialized memory.
void PoisonNew(void* dest, int nitems, type)
"PoisonWith"
Fill up memory with a byte pattern (a byte repeated over and over again) that
hopefully catches attempts to access uninitialized memory.
void PoisonWith(void* dest, int nitems, type, U8 byte)
"StructCopy"
This is an architecture-independent macro that does a shallow copy of one structure to
another.
void StructCopy(type *src, type *dest, type)
"sv_destroyable"
Dummy routine which reports that object can be destroyed when there is no sharing
module present. It ignores its single SV argument, and returns 'true'. Exists to
avoid test for a "NULL" function pointer and because it could potentially warn under
some level of strict-ness.
bool sv_destroyable(SV *sv)
"sv_nosharing"
Dummy routine which "shares" an SV when there is no sharing module present. Or
"locks" it. Or "unlocks" it. In other words, ignores its single SV argument. Exists
to avoid test for a "NULL" function pointer and because it could potentially warn
under some level of strict-ness.
void sv_nosharing(SV *sv)
Versioning
"new_version"
Returns a new version object based on the passed in SV:
SV *sv = new_version(SV *ver);
Does not alter the passed in ver SV. See "upg_version" if you want to upgrade the SV.
SV * new_version(SV *ver)
"PERL_REVISION"
"DEPRECATED!" It is planned to remove "PERL_REVISION" from a future release of Perl.
Do not use it for new code; remove it from existing code.
The major number component of the perl interpreter currently being compiled or
executing. This has been 5 from 1993 into 2020.
Instead use one of the version comparison macros. See "PERL_VERSION_EQ".
"PERL_SUBVERSION"
"DEPRECATED!" It is planned to remove "PERL_SUBVERSION" from a future release of
Perl. Do not use it for new code; remove it from existing code.
The micro number component of the perl interpreter currently being compiled or
executing. In stable releases this gives the dot release number for maintenance
updates. In development releases this gives a tag for a snapshot of the status at
various points in the development cycle.
Instead use one of the version comparison macros. See "PERL_VERSION_EQ".
"PERL_VERSION"
"DEPRECATED!" It is planned to remove "PERL_VERSION" from a future release of Perl.
Do not use it for new code; remove it from existing code.
The minor number component of the perl interpreter currently being compiled or
executing. Between 1993 into 2020, this has ranged from 0 to 33.
Instead use one of the version comparison macros. See "PERL_VERSION_EQ".
"PERL_VERSION_EQ"
"PERL_VERSION_GE"
"PERL_VERSION_GT"
"PERL_VERSION_LE"
"PERL_VERSION_LT"
"PERL_VERSION_NE"
Returns whether or not the perl currently being compiled has the specified
relationship to the perl given by the parameters. For example,
#if PERL_VERSION_GT(5,24,2)
code that will only be compiled on perls after v5.24.2
#else
fallback code
#endif
Note that this is usable in making compile-time decisions
You may use the special value '*' for the final number to mean ALL possible values for
it. Thus,
#if PERL_VERSION_EQ(5,31,'*')
means all perls in the 5.31 series. And
#if PERL_VERSION_NE(5,24,'*')
means all perls EXCEPT 5.24 ones. And
#if PERL_VERSION_LE(5,9,'*')
is effectively
#if PERL_VERSION_LT(5,10,0)
This means you don't have to think so much when converting from the existing
deprecated "PERL_VERSION" to using this macro:
#if PERL_VERSION <= 9
becomes
#if PERL_VERSION_LE(5,9,'*')
bool PERL_VERSION_EQ(const U8 major, const U8 minor,
const U8 patch)
"prescan_version"
Validate that a given string can be parsed as a version object, but doesn't actually
perform the parsing. Can use either strict or lax validation rules. Can optionally
set a number of hint variables to save the parsing code some time when tokenizing.
const char * prescan_version(const char *s, bool strict,
const char **errstr, bool *sqv,
int *ssaw_decimal, int *swidth,
bool *salpha)
"scan_version"
Returns a pointer to the next character after the parsed version string, as well as
upgrading the passed in SV to an RV.
Function must be called with an already existing SV like
sv = newSV(0);
s = scan_version(s, SV *sv, bool qv);
Performs some preprocessing to the string to ensure that it has the correct
characteristics of a version. Flags the object if it contains an underscore (which
denotes this is an alpha version). The boolean qv denotes that the version should be
interpreted as if it had multiple decimals, even if it doesn't.
const char * scan_version(const char *s, SV *rv, bool qv)
"upg_version"
In-place upgrade of the supplied SV to a version object.
SV *sv = upg_version(SV *sv, bool qv);
Returns a pointer to the upgraded SV. Set the boolean qv if you want to force this SV
to be interpreted as an "extended" version.
SV * upg_version(SV *ver, bool qv)
"vcmp"
Version object aware cmp. Both operands must already have been converted into version
objects.
int vcmp(SV *lhv, SV *rhv)
"vnormal"
Accepts a version object and returns the normalized string representation. Call like:
sv = vnormal(rv);
NOTE: you can pass either the object directly or the SV contained within the RV.
The SV returned has a refcount of 1.
SV * vnormal(SV *vs)
"vnumify"
Accepts a version object and returns the normalized floating point representation.
Call like:
sv = vnumify(rv);
NOTE: you can pass either the object directly or the SV contained within the RV.
The SV returned has a refcount of 1.
SV * vnumify(SV *vs)
"vstringify"
In order to maintain maximum compatibility with earlier versions of Perl, this
function will return either the floating point notation or the multiple dotted
notation, depending on whether the original version contained 1 or more dots,
respectively.
The SV returned has a refcount of 1.
SV * vstringify(SV *vs)
"vverify"
Validates that the SV contains valid internal structure for a version object. It may
be passed either the version object (RV) or the hash itself (HV). If the structure is
valid, it returns the HV. If the structure is invalid, it returns NULL.
SV *hv = vverify(sv);
Note that it only confirms the bare minimum structure (so as not to get confused by
derived classes which may contain additional hash entries):
• The SV is an HV or a reference to an HV
• The hash contains a "version" key
• The "version" key has a reference to an AV as its value
SV * vverify(SV *vs)
Warning and Dieing
In all these calls, the "U32 wn" parameters are warning category constants. You can see
the ones currently available in "Category Hierarchy" in warnings, just capitalize all
letters in the names and prefix them by "WARN_". So, for example, the category "void"
used in a perl program becomes "WARN_VOID" when used in XS code and passed to one of the
calls below.
"ckWARN"
"ckWARN2"
"ckWARN3"
"ckWARN4"
These return a boolean as to whether or not warnings are enabled for any of the
warning category(ies) parameters: "w", "w1", ....
Should any of the categories by default be enabled even if not within the scope of
"use warnings", instead use the "ckWARN_d" macros.
The categories must be completely independent, one may not be subclassed from the
other.
bool ckWARN (U32 w)
bool ckWARN2(U32 w1, U32 w2)
bool ckWARN3(U32 w1, U32 w2, U32 w3)
bool ckWARN4(U32 w1, U32 w2, U32 w3, U32 w4)
"ckWARN_d"
"ckWARN2_d"
"ckWARN3_d"
"ckWARN4_d"
Like "ckWARN", but for use if and only if the warning category(ies) is by default
enabled even if not within the scope of "use warnings".
bool ckWARN_d (U32 w)
bool ckWARN2_d(U32 w1, U32 w2)
bool ckWARN3_d(U32 w1, U32 w2, U32 w3)
bool ckWARN4_d(U32 w1, U32 w2, U32 w3, U32 w4)
"ck_warner"
"ck_warner_d"
If none of the warning categories given by "err" are enabled, do nothing; otherwise
call "warner" or "warner_nocontext" with the passed-in parameters;.
"err" must be one of the "packWARN", "packWARN2", "packWARN3", "packWARN4" macros
populated with the appropriate number of warning categories.
The two forms differ only in that "ck_warner_d" should be used if warnings for any of
the categories are by default enabled.
NOTE: "ck_warner" must be explicitly called as "Perl_ck_warner" with an "aTHX_"
parameter.
NOTE: "ck_warner_d" must be explicitly called as "Perl_ck_warner_d" with an "aTHX_"
parameter.
void Perl_ck_warner(pTHX_ U32 err, const char *pat, ...)
"CLEAR_ERRSV"
Clear the contents of $@, setting it to the empty string.
This replaces any read-only SV with a fresh SV and removes any magic.
void CLEAR_ERRSV()
"croak"
"croak_nocontext"
These are XS interfaces to Perl's "die" function.
They take a sprintf-style format pattern and argument list, which are used to generate
a string message. If the message does not end with a newline, then it will be
extended with some indication of the current location in the code, as described for
"mess_sv".
The error message will be used as an exception, by default returning control to the
nearest enclosing "eval", but subject to modification by a $SIG{__DIE__} handler. In
any case, these croak functions never return normally.
For historical reasons, if "pat" is null then the contents of "ERRSV" ($@) will be
used as an error message or object instead of building an error message from
arguments. If you want to throw a non-string object, or build an error message in an
SV yourself, it is preferable to use the "croak_sv" function, which does not involve
clobbering "ERRSV".
The two forms differ only in that "croak_nocontext" does not take a thread context
("aTHX") parameter. It is usually preferred as it takes up fewer bytes of code than
plain "Perl_croak", and time is rarely a critical resource when you are about to throw
an exception.
NOTE: "croak" must be explicitly called as "Perl_croak" with an "aTHX_" parameter.
void Perl_croak (pTHX_ const char *pat, ...)
void croak_nocontext(const char *pat, ...)
"croak_no_modify"
This encapsulates a common reason for dying, generating terser object code than using
the generic "Perl_croak". It is exactly equivalent to "Perl_croak(aTHX_ "%s",
PL_no_modify)" (which expands to something like "Modification of a read-only value
attempted").
Less code used on exception code paths reduces CPU cache pressure.
void croak_no_modify()
"croak_sv"
This is an XS interface to Perl's "die" function.
"baseex" is the error message or object. If it is a reference, it will be used as-is.
Otherwise it is used as a string, and if it does not end with a newline then it will
be extended with some indication of the current location in the code, as described for
"mess_sv".
The error message or object will be used as an exception, by default returning control
to the nearest enclosing "eval", but subject to modification by a $SIG{__DIE__}
handler. In any case, the "croak_sv" function never returns normally.
To die with a simple string message, the "croak" function may be more convenient.
void croak_sv(SV *baseex)
"die"
"die_nocontext"
These behave the same as "croak", except for the return type. They should be used
only where the "OP *" return type is required. They never actually return.
The two forms differ only in that "die_nocontext" does not take a thread context
("aTHX") parameter, so is used in situations where the caller doesn't already have the
thread context.
NOTE: "die" must be explicitly called as "Perl_die" with an "aTHX_" parameter.
OP * Perl_die (pTHX_ const char *pat, ...)
OP * die_nocontext(const char *pat, ...)
"die_sv"
This behaves the same as "croak_sv", except for the return type. It should be used
only where the "OP *" return type is required. The function never actually returns.
OP * die_sv(SV *baseex)
"ERRSV"
Returns the SV for $@, creating it if needed.
SV * ERRSV
"fatal_warner"
Like "warner" except that it acts as if fatal warnings are enabled for the warning.
If called when there are pending compilation errors this function may return.
This is currently used to generate "used only once" fatal warnings since the COP where
the name being reported is no longer the current COP when the warning is generated and
may be useful for similar cases.
"err" must be one of the "packWARN", "packWARN2", "packWARN3", "packWARN4" macros
populated with the appropriate number of warning categories.
NOTE: "fatal_warner" must be explicitly called as "Perl_fatal_warner" with an "aTHX_"
parameter.
void Perl_fatal_warner(pTHX_ U32 err, const char *pat, ...)
"packWARN"
"packWARN2"
"packWARN3"
"packWARN4"
These macros are used to pack warning categories into a single U32 to pass to macros
and functions that take a warning category parameter. The number of categories to
pack is given by the name, with a corresponding number of category parameters passed.
U32 packWARN (U32 w1)
U32 packWARN2(U32 w1, U32 w2)
U32 packWARN3(U32 w1, U32 w2, U32 w3)
U32 packWARN4(U32 w1, U32 w2, U32 w3, U32 w4)
"SANE_ERRSV"
Clean up ERRSV so we can safely set it.
This replaces any read-only SV with a fresh writable copy and removes any magic.
void SANE_ERRSV()
"vcroak"
This is an XS interface to Perl's "die" function.
"pat" and "args" are a sprintf-style format pattern and encapsulated argument list.
These are used to generate a string message. If the message does not end with a
newline, then it will be extended with some indication of the current location in the
code, as described for "mess_sv".
The error message will be used as an exception, by default returning control to the
nearest enclosing "eval", but subject to modification by a $SIG{__DIE__} handler. In
any case, the "croak" function never returns normally.
For historical reasons, if "pat" is null then the contents of "ERRSV" ($@) will be
used as an error message or object instead of building an error message from
arguments. If you want to throw a non-string object, or build an error message in an
SV yourself, it is preferable to use the "croak_sv" function, which does not involve
clobbering "ERRSV".
void vcroak(const char *pat, va_list *args)
"vfatal_warner"
This is like "fatal_warner" but "args" are an encapsulated argument list.
void vfatal_warner(U32 err, const char *pat, va_list *args)
"vwarn"
This is an XS interface to Perl's "warn" function.
This is like "warn", but "args" are an encapsulated argument list.
Unlike with "vcroak", "pat" is not permitted to be null.
void vwarn(const char *pat, va_list *args)
"vwarner"
This is like "warner", but "args" are an encapsulated argument list.
void vwarner(U32 err, const char *pat, va_list *args)
"warn"
"warn_nocontext"
These are XS interfaces to Perl's "warn" function.
They take a sprintf-style format pattern and argument list, which are used to
generate a string message. If the message does not end with a newline, then it will
be extended with some indication of the current location in the code, as described for
"mess_sv".
The error message or object will by default be written to standard error, but this is
subject to modification by a $SIG{__WARN__} handler.
Unlike with "croak", "pat" is not permitted to be null.
The two forms differ only in that "warn_nocontext" does not take a thread context
("aTHX") parameter, so is used in situations where the caller doesn't already have the
thread context.
NOTE: "warn" must be explicitly called as "Perl_warn" with an "aTHX_" parameter.
void Perl_warn (pTHX_ const char *pat, ...)
void warn_nocontext(const char *pat, ...)
"warner"
"warner_nocontext"
These output a warning of the specified category (or categories) given by "err", using
the sprintf-style format pattern "pat", and argument list.
"err" must be one of the "packWARN", "packWARN2", "packWARN3", "packWARN4" macros
populated with the appropriate number of warning categories. If any of the warning
categories they specify is fatal, a fatal exception is thrown.
In any event a message is generated by the pattern and arguments. If the message does
not end with a newline, then it will be extended with some indication of the current
location in the code, as described for "mess_sv".
The error message or object will by default be written to standard error, but this is
subject to modification by a $SIG{__WARN__} handler.
"pat" is not permitted to be null.
The two forms differ only in that "warner_nocontext" does not take a thread context
("aTHX") parameter, so is used in situations where the caller doesn't already have the
thread context.
These functions differ from the similarly named "warn" functions, in that the latter
are for XS code to unconditionally display a warning, whereas these are for code that
may be compiling a perl program, and does extra checking to see if the warning should
be fatal.
NOTE: "warner" must be explicitly called as "Perl_warner" with an "aTHX_" parameter.
void Perl_warner (pTHX_ U32 err, const char *pat, ...)
void warner_nocontext(U32 err, const char *pat, ...)
"warn_sv"
This is an XS interface to Perl's "warn" function.
"baseex" is the error message or object. If it is a reference, it will be used as-is.
Otherwise it is used as a string, and if it does not end with a newline then it will
be extended with some indication of the current location in the code, as described for
"mess_sv".
The error message or object will by default be written to standard error, but this is
subject to modification by a $SIG{__WARN__} handler.
To warn with a simple string message, the "warn" function may be more convenient.
void warn_sv(SV *baseex)
XS
xsubpp compiles XS code into C. See "xsubpp" in perlutil.
"aMY_CXT"
Described in perlxs.
"_aMY_CXT"
Described in perlxs.
"aMY_CXT_"
Described in perlxs.
"ax"
Variable which is setup by "xsubpp" to indicate the stack base offset, used by the
"ST", "XSprePUSH" and "XSRETURN" macros. The "dMARK" macro must be called prior to
setup the "MARK" variable.
Stack_off_t ax
"CLASS"
Variable which is setup by "xsubpp" to indicate the class name for a C++ XS
constructor. This is always a "char*". See "THIS".
char* CLASS
"dAX"
Sets up the "ax" variable. This is usually handled automatically by "xsubpp" by
calling "dXSARGS".
dAX;
"dAXMARK"
Sets up the "ax" variable and stack marker variable "mark". This is usually handled
automatically by "xsubpp" by calling "dXSARGS".
dAXMARK;
"dITEMS"
Sets up the "items" variable. This is usually handled automatically by "xsubpp" by
calling "dXSARGS".
dITEMS;
"dMY_CXT"
Described in perlxs.
"dMY_CXT_SV"
Now a placeholder that declares nothing
dMY_CXT_SV;
"dUNDERBAR"
Sets up any variable needed by the "UNDERBAR" macro. It used to define "padoff_du",
but it is currently a noop. However, it is strongly advised to still use it for
ensuring past and future compatibility.
dUNDERBAR;
"dXSARGS"
Sets up stack and mark pointers for an XSUB, calling "dSP" and "dMARK". Sets up the
"ax" and "items" variables by calling "dAX" and "dITEMS". This is usually handled
automatically by "xsubpp".
dXSARGS;
"dXSI32"
Sets up the "ix" variable for an XSUB which has aliases. This is usually handled
automatically by "xsubpp".
dXSI32;
"items"
Variable which is setup by "xsubpp" to indicate the number of items on the stack. See
"Variable-length Parameter Lists" in perlxs.
Stack_off_t items
"ix"
Variable which is setup by "xsubpp" to indicate which of an XSUB's aliases was used to
invoke it. See "The ALIAS: Keyword" in perlxs.
I32 ix
"MY_CXT"
Described in perlxs.
"MY_CXT_CLONE"
Described in perlxs.
"MY_CXT_INIT"
Described in perlxs.
"pMY_CXT"
Described in perlxs.
"_pMY_CXT"
Described in perlxs.
"pMY_CXT_"
Described in perlxs.
"RETVAL"
Variable which is setup by "xsubpp" to hold the return value for an XSUB. This is
always the proper type for the XSUB. See "The RETVAL Variable" in perlxs.
type RETVAL
"ST"
Used to access elements on the XSUB's stack.
SV* ST(int ix)
"START_MY_CXT"
Described in perlxs.
"THIS"
Variable which is setup by "xsubpp" to designate the object in a C++ XSUB. This is
always the proper type for the C++ object. See "CLASS" and "Using XS With C++" in
perlxs.
type THIS
"UNDERBAR"
The SV* corresponding to the $_ variable. Works even if there is a lexical $_ in
scope.
"XS"
Macro to declare an XSUB and its C parameter list. This is handled by "xsubpp". It
is the same as using the more explicit "XS_EXTERNAL" macro; the latter is preferred.
"XS_EXTERNAL"
Macro to declare an XSUB and its C parameter list explicitly exporting the symbols.
"XS_INTERNAL"
Macro to declare an XSUB and its C parameter list without exporting the symbols. This
is handled by "xsubpp" and generally preferable over exporting the XSUB symbols
unnecessarily.
"XSPROTO"
Macro used by "XS_INTERNAL" and "XS_EXTERNAL" to declare a function prototype. You
probably shouldn't be using this directly yourself.
Undocumented elements
The following functions have been flagged as part of the public API, but are currently
undocumented. Use them at your own risk, as the interfaces are subject to change.
Functions that are not listed in this document are not intended for public use, and should
NOT be used under any circumstances.
If you feel you need to use one of these functions, first send email to
perl5-porters@perl.org <mailto:perl5-porters@perl.org>. It may be that there is a good
reason for the function not being documented, and it should be removed from this list; or
it may just be that no one has gotten around to documenting it. In the latter case, you
will be asked to submit a patch to document the function. Once your patch is accepted, it
will indicate that the interface is stable (unless it is explicitly marked otherwise) and
usable by you.
clone_params_del do_open PERL_BUILD_DATE sv_dup
clone_params_new do_openn resume_compcv sv_dup_inc
Next are the API-flagged elements that are considered experimental. Using one of these is
even more risky than plain undocumented ones. They are listed here because they should be
listed somewhere (so their existence doesn't get lost) and this is the best place for
them.
apply_attrs_string hv_store_flags thread_locale_init
gv_fetchmethod_pv_flags leave_adjust_stacks thread_locale_term
gv_fetchmethod_pvn_flags newXS_flags
gv_fetchmethod_sv_flags savetmps
Finally are deprecated undocumented API elements. Do not use any for new code; remove all
occurrences of all of these from existing code.
There are currently no items of this type
AUTHORS
Until May 1997, this document was maintained by Jeff Okamoto <okamoto@corp.hp.com>. It is
now maintained as part of Perl itself.
With lots of help and suggestions from Dean Roehrich, Malcolm Beattie, Andreas Koenig,
Paul Hudson, Ilya Zakharevich, Paul Marquess, Neil Bowers, Matthew Green, Tim Bunce,
Spider Boardman, Ulrich Pfeifer, Stephen McCamant, and Gurusamy Sarathy.
API Listing originally by Dean Roehrich <roehrich@cray.com>.
Updated to be autogenerated from comments in the source by Benjamin Stuhl.
SEE ALSO
config.h, perlapio, perlcall, perlclib, perlembed, perlfilter, perlguts, perlhacktips,
perlintern, perlinterp, perliol, perlmroapi, perlreapi, perlreguts, perlxs