Provided by: perl-doc_5.30.0-9ubuntu0.5_all 
NAME
perlapi - autogenerated documentation for the perl public API
DESCRIPTION
This file contains the documentation of the perl public API generated by embed.pl, specifically a listing
of functions, macros, flags, and variables that may be used by extension writers. At the end is a list
of functions which have yet to be documented. The interfaces of those are subject to change without
notice. Anything not listed here 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 can 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 somethimes 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 listing below is alphabetical, case insensitive.
Array Manipulation Functions
av_clear
Frees the 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_create_and_push
NOTE: this function is experimental and may change or be removed without notice.
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.
void av_create_and_push(AV **const avp,
SV *const val)
av_create_and_unshift_one
NOTE: this function is experimental and may change or be removed without notice.
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.
SV** av_create_and_unshift_one(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. The "key" is the index to which the array should be extended.
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()".
int AvFILL(AV* av)
av_fill Set the highest index in the array to the given number, equivalent to Perl's "$#array = $fill;".
The number of elements in the array will be "fill + 1" after "av_fill()" returns. If the array
was previously shorter, then the additional elements appended are set to NULL. If the array was
longer, then the excess elements are freed. "av_fill(av, -1)" is the same as "av_clear(av)".
void av_fill(AV *av, SSize_t fill)
av_len Same as "av_top_index". Note that, unlike what the name implies, it returns the highest index in
the array, so to get the size of the array you need to use "av_len(av) + 1". This is unlike
"sv_len", which returns what you would expect.
SSize_t av_len(AV *av)
av_make Creates a new AV and populates it with a list of SVs. The SVs are copied into the array, so they
may be freed after the call to "av_make". The new AV will have a reference count of 1.
Perl equivalent: "my @new_array = ($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_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
Same as "av_top_index()".
int av_tindex(AV* av)
av_top_index
Returns the highest index in the array. The number of elements in the array is
"av_top_index(av) + 1". Returns -1 if the array is empty.
The Perl equivalent for this is $#myarray.
(A slightly shorter form is "av_tindex".)
SSize_t av_top_index(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 $num);"
void av_unshift(AV *av, SSize_t num)
get_av Returns the AV of the specified Perl global or package array with the given name (so it won't
work on lexical variables). "flags" are passed to "gv_fetchpv". If "GV_ADD" is set and the Perl
variable does not exist then it will be created. If "flags" is zero and the variable does not
exist then NULL is returned.
Perl equivalent: "@{"$name"}".
NOTE: the perl_ form of this function is deprecated.
AV* get_av(const char *name, I32 flags)
newAV Creates a new AV. The reference count is set to 1.
Perl equivalent: "my @array;".
AV* newAV()
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)
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_ form of this function is deprecated.
I32 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_ form of this function is deprecated.
I32 call_method(const char* methname, I32 flags)
call_pv Performs a callback to the specified Perl sub. See perlcall.
NOTE: the perl_ form of this function is deprecated.
I32 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_ form of this function is deprecated.
I32 call_sv(SV* sv, volatile I32 flags)
ENTER Opening bracket on a callback. See "LEAVE" and perlcall.
ENTER;
ENTER_with_name(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_ form of this function 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.
NOTE: the perl_ form of this function is deprecated.
I32 eval_sv(SV* sv, I32 flags)
FREETMPS
Closing bracket for temporaries on a callback. See "SAVETMPS" and perlcall.
FREETMPS;
LEAVE Closing bracket on a callback. See "ENTER" and perlcall.
LEAVE;
LEAVE_with_name(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);
SAVETMPS
Opening bracket for temporaries on a callback. See "FREETMPS" and perlcall.
SAVETMPS;
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 Converts the specified character to foldcase. If the input is anything but an ASCII uppercase
character, that input character itself is returned. Variant "toFOLD_A" is equivalent. (There is
no equivalent "to_FOLD_L1" for the full Latin1 range, as the full generality of "toFOLD_uvchr" is
needed there.)
U8 toFOLD(U8 ch)
toFOLD_utf8
This is like "toFOLD_utf8_safe", but doesn't have the "e" parameter The function therefore can't
check if it is reading beyond the end of the string. Starting in Perl v5.30, it will take the
"e" parameter, becoming a synonym for "toFOLD_utf8_safe". At that time every program that uses
it will have to be changed to successfully compile. In the meantime, the first runtime call to
"toFOLD_utf8" from each call point in the program will raise a deprecation warning, enabled by
default. You can convert your program now to use "toFOLD_utf8_safe", and avoid the warnings, and
get an extra measure of protection, or you can wait until v5.30, when you'll be forced to add the
"e" parameter.
UV toFOLD_utf8(U8* p, U8* s, STRLEN* lenp)
toFOLD_utf8_safe
Converts the first UTF-8 encoded character in the sequence starting at "p" and extending no
further than "e - 1" to its foldcase version, and stores that in UTF-8 in "s", and its length in
bytes in "lenp". Note that the buffer pointed to by "s" needs to be at least
"UTF8_MAXBYTES_CASE+1" bytes since the foldcase version may be longer than the original
character.
The first code point of the foldcased version is returned (but note, as explained at the top of
this section, that there may be more).
The suffix "_safe" in the function's name indicates 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 the REPLACEMENT CHARACTER, at the discretion of the implementation,
and subject to change in future releases.
UV toFOLD_utf8_safe(U8* p, U8* e, U8* s,
STRLEN* lenp)
toFOLD_uvchr
Converts the code point "cp" to its foldcase version, and stores that in UTF-8 in "s", and its
length in bytes in "lenp". The code point is interpreted as native if less than 256; otherwise
as Unicode. Note that the buffer pointed to by "s" needs to be at least "UTF8_MAXBYTES_CASE+1"
bytes since the foldcase version may be longer than the original character.
The first code point of the foldcased version is returned (but note, as explained at the top of
this section, that there may be more).
UV toFOLD_uvchr(UV cp, U8* s, STRLEN* lenp)
toLOWER Converts the specified character to lowercase. If the input is anything but an ASCII uppercase
character, that input character itself is returned. Variant "toLOWER_A" is equivalent.
U8 toLOWER(U8 ch)
toLOWER_L1
Converts the specified Latin1 character to lowercase. The results are undefined if the input
doesn't fit in a byte.
U8 toLOWER_L1(U8 ch)
toLOWER_LC
Converts the specified character to lowercase using the current locale's rules, if possible;
otherwise returns the input character itself.
U8 toLOWER_LC(U8 ch)
toLOWER_utf8
This is like "toLOWER_utf8_safe", but doesn't have the "e" parameter The function therefore
can't check if it is reading beyond the end of the string. Starting in Perl v5.30, it will take
the "e" parameter, becoming a synonym for "toLOWER_utf8_safe". At that time every program that
uses it will have to be changed to successfully compile. In the meantime, the first runtime call
to "toLOWER_utf8" from each call point in the program will raise a deprecation warning, enabled
by default. You can convert your program now to use "toLOWER_utf8_safe", and avoid the warnings,
and get an extra measure of protection, or you can wait until v5.30, when you'll be forced to add
the "e" parameter.
UV toLOWER_utf8(U8* p, U8* s, STRLEN* lenp)
toLOWER_utf8_safe
Converts the first UTF-8 encoded character in the sequence starting at "p" and extending no
further than "e - 1" to its lowercase version, and stores that in UTF-8 in "s", and its length in
bytes in "lenp". Note that the buffer pointed to by "s" needs to be at least
"UTF8_MAXBYTES_CASE+1" bytes since the lowercase version may be longer than the original
character.
The first code point of the lowercased version is returned (but note, as explained at the top of
this section, that there may be more).
The suffix "_safe" in the function's name indicates 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 the REPLACEMENT CHARACTER, at the discretion of the implementation,
and subject to change in future releases.
UV toLOWER_utf8_safe(U8* p, U8* e, U8* s,
STRLEN* lenp)
toLOWER_uvchr
Converts the code point "cp" to its lowercase version, and stores that in UTF-8 in "s", and its
length in bytes in "lenp". The code point is interpreted as native if less than 256; otherwise
as Unicode. Note that the buffer pointed to by "s" needs to be at least "UTF8_MAXBYTES_CASE+1"
bytes since the lowercase version may be longer than the original character.
The first code point of the lowercased version is returned (but note, as explained at the top of
this section, that there may be more).
UV toLOWER_uvchr(UV cp, U8* s, STRLEN* lenp)
toTITLE Converts the specified character to titlecase. If the input is anything but an ASCII lowercase
character, that input character itself is returned. Variant "toTITLE_A" is equivalent. (There
is no "toTITLE_L1" for the full Latin1 range, as the full generality of "toTITLE_uvchr" is needed
there. Titlecase is not a concept used in locale handling, so there is no functionality for
that.)
U8 toTITLE(U8 ch)
toTITLE_utf8
This is like "toLOWER_utf8_safe", but doesn't have the "e" parameter The function therefore
can't check if it is reading beyond the end of the string. Starting in Perl v5.30, it will take
the "e" parameter, becoming a synonym for "toTITLE_utf8_safe". At that time every program that
uses it will have to be changed to successfully compile. In the meantime, the first runtime call
to "toTITLE_utf8" from each call point in the program will raise a deprecation warning, enabled
by default. You can convert your program now to use "toTITLE_utf8_safe", and avoid the warnings,
and get an extra measure of protection, or you can wait until v5.30, when you'll be forced to add
the "e" parameter.
UV toTITLE_utf8(U8* p, U8* s, STRLEN* lenp)
toTITLE_utf8_safe
Converts the first UTF-8 encoded character in the sequence starting at "p" and extending no
further than "e - 1" to its titlecase version, and stores that in UTF-8 in "s", and its length in
bytes in "lenp". Note that the buffer pointed to by "s" needs to be at least
"UTF8_MAXBYTES_CASE+1" bytes since the titlecase version may be longer than the original
character.
The first code point of the titlecased version is returned (but note, as explained at the top of
this section, that there may be more).
The suffix "_safe" in the function's name indicates 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 the REPLACEMENT CHARACTER, at the discretion of the implementation,
and subject to change in future releases.
UV toTITLE_utf8_safe(U8* p, U8* e, U8* s,
STRLEN* lenp)
toTITLE_uvchr
Converts the code point "cp" to its titlecase version, and stores that in UTF-8 in "s", and its
length in bytes in "lenp". The code point is interpreted as native if less than 256; otherwise
as Unicode. Note that the buffer pointed to by "s" needs to be at least "UTF8_MAXBYTES_CASE+1"
bytes since the titlecase version may be longer than the original character.
The first code point of the titlecased version is returned (but note, as explained at the top of
this section, that there may be more).
UV toTITLE_uvchr(UV cp, U8* s, STRLEN* lenp)
toUPPER Converts the specified character to uppercase. If the input is anything but an ASCII lowercase
character, that input character itself is returned. Variant "toUPPER_A" is equivalent.
U8 toUPPER(U8 ch)
toUPPER_utf8
This is like "toUPPER_utf8_safe", but doesn't have the "e" parameter The function therefore
can't check if it is reading beyond the end of the string. Starting in Perl v5.30, it will take
the "e" parameter, becoming a synonym for "toUPPER_utf8_safe". At that time every program that
uses it will have to be changed to successfully compile. In the meantime, the first runtime call
to "toUPPER_utf8" from each call point in the program will raise a deprecation warning, enabled
by default. You can convert your program now to use "toUPPER_utf8_safe", and avoid the warnings,
and get an extra measure of protection, or you can wait until v5.30, when you'll be forced to add
the "e" parameter.
UV toUPPER_utf8(U8* p, U8* s, STRLEN* lenp)
toUPPER_utf8_safe
Converts the first UTF-8 encoded character in the sequence starting at "p" and extending no
further than "e - 1" to its uppercase version, and stores that in UTF-8 in "s", and its length in
bytes in "lenp". Note that the buffer pointed to by "s" needs to be at least
"UTF8_MAXBYTES_CASE+1" bytes since the uppercase version may be longer than the original
character.
The first code point of the uppercased version is returned (but note, as explained at the top of
this section, that there may be more).
The suffix "_safe" in the function's name indicates 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 the REPLACEMENT CHARACTER, at the discretion of the implementation,
and subject to change in future releases.
UV toUPPER_utf8_safe(U8* p, U8* e, U8* s,
STRLEN* lenp)
toUPPER_uvchr
Converts the code point "cp" to its uppercase version, and stores that in UTF-8 in "s", and its
length in bytes in "lenp". The code point is interpreted as native if less than 256; otherwise
as Unicode. Note that the buffer pointed to by "s" needs to be at least "UTF8_MAXBYTES_CASE+1"
bytes since the uppercase version may be longer than the original character.
The first code point of the uppercased version is returned (but note, as explained at the top of
this section, that there may be more.)
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 an octet (either a "char" or a "U8") as input and returns a
boolean as to whether or not the character represented by that octet 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).
Variant "isFOO_uvchr" is like the "isFOO_L1" variant, but accepts any UV code point as input. 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.
Variant "isFOO_utf8_safe" is like "isFOO_uvchr", but is used for UTF-8 encoded strings. Each call
classifies one character, even if the string contains many. This variant takes two parameters. The
first, "p", is a pointer to the first byte of the character to be classified. (Recall that it may take
more than one byte to represent a character in UTF-8 strings.) 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. The
suffix "_safe" in the function's name indicates 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_utf8" is like "isFOO_utf8_safe", but takes just a single parameter, "p", which has the
same meaning as the corresponding parameter does in "isFOO_utf8_safe". The function therefore can't
check if it is reading beyond the end of the string. Starting in Perl v5.30, it will take a second
parameter, becoming a synonym for "isFOO_utf8_safe". At that time every program that uses it will have
to be changed to successfully compile. In the meantime, the first runtime call to "isFOO_utf8" from each
call point in the program will raise a deprecation warning, enabled by default. You can convert your
program now to use "isFOO_utf8_safe", and avoid the warnings, and get an extra measure of protection, or
you can wait until v5.30, when you'll be forced to add the "e" parameter.
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" is like "isFOO_LC", but is defined on any UV. It returns the same as "isFOO_LC"
for input code points less than 256, and returns the hard-coded, not-affected-by-locale, Unicode results
for larger ones.
Variant "isFOO_LC_utf8_safe" is like "isFOO_LC_uvchr", but is used for UTF-8 encoded strings. Each call
classifies one character, even if the string contains many. This variant takes two parameters. The
first, "p", is a pointer to the first byte of the character to be classified. (Recall that it may take
more than one byte to represent a character in UTF-8 strings.) 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. The
suffix "_safe" in the function's name indicates 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_utf8" is like "isFOO_LC_utf8_safe", but takes just a single parameter, "p", which has
the same meaning as the corresponding parameter does in "isFOO_LC_utf8_safe". The function therefore
can't check if it is reading beyond the end of the string. Starting in Perl v5.30, it will take a second
parameter, becoming a synonym for "isFOO_LC_utf8_safe". At that time every program that uses it will
have to be changed to successfully compile. In the meantime, the first runtime call to "isFOO_LC_utf8"
from each call point in the program will raise a deprecation warning, enabled by default. You can
convert your program now to use "isFOO_LC_utf8_safe", and avoid the warnings, and get an extra measure of
protection, or you can wait until v5.30, when you'll be forced to add the "e" parameter.
isALPHA Returns a boolean indicating whether the specified character is an alphabetic character,
analogous to "m/[[:alpha:]]/". See the top of this section for an explanation of variants
"isALPHA_A", "isALPHA_L1", "isALPHA_uvchr", "isALPHA_utf8_safe", "isALPHA_LC",
"isALPHA_LC_uvchr", and "isALPHA_LC_utf8_safe".
bool isALPHA(char ch)
isALPHANUMERIC
Returns a boolean indicating whether the specified character is a either an alphabetic character
or decimal digit, analogous to "m/[[:alnum:]]/". See the top of this section for an explanation
of variants "isALPHANUMERIC_A", "isALPHANUMERIC_L1", "isALPHANUMERIC_uvchr",
"isALPHANUMERIC_utf8_safe", "isALPHANUMERIC_LC", "isALPHANUMERIC_LC_uvchr", and
"isALPHANUMERIC_LC_utf8_safe".
bool isALPHANUMERIC(char ch)
isASCII 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 variants
"isASCII_uvchr", "isASCII_utf8_safe", "isASCII_LC", "isASCII_LC_uvchr", and
"isASCII_LC_utf8_safe". 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_safe" will work properly on any string encoded or not in UTF-8.
bool isASCII(char ch)
isBLANK 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 variants
"isBLANK_A", "isBLANK_L1", "isBLANK_uvchr", "isBLANK_utf8_safe", "isBLANK_LC",
"isBLANK_LC_uvchr", and "isBLANK_LC_utf8_safe". 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(char ch)
isCNTRL 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 variants "isCNTRL_A",
"isCNTRL_L1", "isCNTRL_uvchr", "isCNTRL_utf8_safe", "isCNTRL_LC", "isCNTRL_LC_uvchr", and
"isCNTRL_LC_utf8_safe" On EBCDIC platforms, you almost always want to use the "isCNTRL_L1"
variant.
bool isCNTRL(char ch)
isDIGIT 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 variants "isDIGIT_uvchr", "isDIGIT_utf8_safe",
"isDIGIT_LC", "isDIGIT_LC_uvchr", and "isDIGIT_LC_utf8_safe".
bool isDIGIT(char ch)
isGRAPH 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 variants "isGRAPH_A",
"isGRAPH_L1", "isGRAPH_uvchr", "isGRAPH_utf8_safe", "isGRAPH_LC", "isGRAPH_LC_uvchr", and
"isGRAPH_LC_utf8_safe".
bool isGRAPH(char ch)
isIDCONT
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 variants
"isIDCONT_A", "isIDCONT_L1", "isIDCONT_uvchr", "isIDCONT_utf8_safe", "isIDCONT_LC",
"isIDCONT_LC_uvchr", and "isIDCONT_LC_utf8_safe".
bool isIDCONT(char ch)
isIDFIRST
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 variants "isIDFIRST_A",
"isIDFIRST_L1", "isIDFIRST_uvchr", "isIDFIRST_utf8_safe", "isIDFIRST_LC", "isIDFIRST_LC_uvchr",
and "isIDFIRST_LC_utf8_safe".
bool isIDFIRST(char ch)
isLOWER 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 variants "isLOWER_A",
"isLOWER_L1", "isLOWER_uvchr", "isLOWER_utf8_safe", "isLOWER_LC", "isLOWER_LC_uvchr", and
"isLOWER_LC_utf8_safe".
bool isLOWER(char ch)
isOCTAL 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(char ch)
isPRINT 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 variants "isPRINT_A",
"isPRINT_L1", "isPRINT_uvchr", "isPRINT_utf8_safe", "isPRINT_LC", "isPRINT_LC_uvchr", and
"isPRINT_LC_utf8_safe".
bool isPRINT(char ch)
isPSXSPC
(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 variants "isPSXSPC_A", "isPSXSPC_L1", "isPSXSPC_uvchr", "isPSXSPC_utf8_safe", "isPSXSPC_LC",
"isPSXSPC_LC_uvchr", and "isPSXSPC_LC_utf8_safe".
bool isPSXSPC(char ch)
isPUNCT 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 variants "isPUNCT_A", "isPUNCT_L1",
"isPUNCT_uvchr", "isPUNCT_utf8_safe", "isPUNCT_LC", "isPUNCT_LC_uvchr", and
"isPUNCT_LC_utf8_safe".
bool isPUNCT(char ch)
isSPACE 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 variants "isSPACE_A", "isSPACE_L1", "isSPACE_uvchr",
"isSPACE_utf8_safe", "isSPACE_LC", "isSPACE_LC_uvchr", and "isSPACE_LC_utf8_safe".
bool isSPACE(char ch)
isUPPER 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 variants "isUPPER_A",
"isUPPER_L1", "isUPPER_uvchr", "isUPPER_utf8_safe", "isUPPER_LC", "isUPPER_LC_uvchr", and
"isUPPER_LC_utf8_safe".
bool isUPPER(char ch)
isWORDCHAR
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). "isALNUM()" is a synonym provided for backward compatibility, even though a word
character includes more than the standard C language meaning of alphanumeric. See the top of
this section for an explanation of variants "isWORDCHAR_A", "isWORDCHAR_L1", "isWORDCHAR_uvchr",
and "isWORDCHAR_utf8_safe". "isWORDCHAR_LC", "isWORDCHAR_LC_uvchr", and
"isWORDCHAR_LC_utf8_safe" are also as described there, but additionally include the platform's
native underscore.
bool isWORDCHAR(char ch)
isXDIGIT
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 variants "isXDIGIT_uvchr",
"isXDIGIT_utf8_safe", "isXDIGIT_LC", "isXDIGIT_LC_uvchr", and "isXDIGIT_LC_utf8_safe".
bool isXDIGIT(char ch)
Cloning an interpreter
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;", reason to keep it around is if you want to
dup some of your own variable who are outside the graph perl scans, an example of this code is in
threads.xs create.
"CLONEf_CLONE_HOST" - This is a win32 thing, it is ignored on unix, it tells perls 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
)
Compile-time scope hooks
BhkDISABLE
NOTE: this function 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, which)
BhkENABLE
NOTE: this function 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, which)
BhkENTRY_set
NOTE: this function 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, which, void *ptr)
blockhook_register
NOTE: this function 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: this function must be explicitly called as Perl_blockhook_register with an aTHX_ parameter.
void Perl_blockhook_register(pTHX_ BHK *hk)
COP Hint Hashes
cophh_2hv
NOTE: this function 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_copy
NOTE: this function 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
NOTE: this function is experimental and may change or be removed without notice.
Like "cophh_delete_pvn", but takes a nul-terminated string instead of a string/length pair.
COPHH * cophh_delete_pv(const COPHH *cophh,
const char *key, U32 hash,
U32 flags)
cophh_delete_pvn
NOTE: this function is experimental and may change or be removed without notice.
Delete a key and its associated value from the cop hints hash "cophh", and returns 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 key is specified by "keypv" and "keylen". If "flags" has the "COPHH_KEY_UTF8" bit set, the
key octets are interpreted as UTF-8, otherwise they are interpreted as Latin-1. "hash" is a
precomputed hash of the key string, or zero if it has not been precomputed.
COPHH * cophh_delete_pvn(COPHH *cophh,
const char *keypv,
STRLEN keylen, U32 hash,
U32 flags)
cophh_delete_pvs
NOTE: this function is experimental and may change or be removed without notice.
Like "cophh_delete_pvn", but takes a literal string instead of a string/length pair, and no
precomputed hash.
COPHH * cophh_delete_pvs(const COPHH *cophh,
"literal string" key,
U32 flags)
cophh_delete_sv
NOTE: this function is experimental and may change or be removed without notice.
Like "cophh_delete_pvn", but takes a Perl scalar instead of a string/length pair.
COPHH * cophh_delete_sv(const COPHH *cophh, SV *key,
U32 hash, U32 flags)
cophh_fetch_pv
NOTE: this function is experimental and may change or be removed without notice.
Like "cophh_fetch_pvn", but takes a nul-terminated string instead of a string/length pair.
SV * cophh_fetch_pv(const COPHH *cophh,
const char *key, U32 hash,
U32 flags)
cophh_fetch_pvn
NOTE: this function is experimental and may change or be removed without notice.
Look up the entry in the cop hints hash "cophh" with the key specified by "keypv" and "keylen".
If "flags" has the "COPHH_KEY_UTF8" bit set, the key octets are interpreted as UTF-8, otherwise
they are interpreted as Latin-1. "hash" is a precomputed hash of the key string, or zero if it
has not been precomputed. Returns a mortal scalar copy of the value associated with the key, or
&PL_sv_placeholder if there is no value associated with the key.
SV * cophh_fetch_pvn(const COPHH *cophh,
const char *keypv,
STRLEN keylen, U32 hash,
U32 flags)
cophh_fetch_pvs
NOTE: this function is experimental and may change or be removed without notice.
Like "cophh_fetch_pvn", but takes a literal string instead of a string/length pair, and no
precomputed hash.
SV * cophh_fetch_pvs(const COPHH *cophh,
"literal string" key, U32 flags)
cophh_fetch_sv
NOTE: this function is experimental and may change or be removed without notice.
Like "cophh_fetch_pvn", but takes a Perl scalar instead of a string/length pair.
SV * cophh_fetch_sv(const COPHH *cophh, SV *key,
U32 hash, U32 flags)
cophh_free
NOTE: this function 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_new_empty
NOTE: this function 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
NOTE: this function is experimental and may change or be removed without notice.
Like "cophh_store_pvn", but takes a nul-terminated string instead of a string/length pair.
COPHH * cophh_store_pv(const COPHH *cophh,
const char *key, U32 hash,
SV *value, U32 flags)
cophh_store_pvn
NOTE: this function is experimental and may change or be removed without notice.
Stores a value, associated with a key, in the cop hints hash "cophh", and returns 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 key is specified by "keypv" and "keylen". If "flags" has the "COPHH_KEY_UTF8" bit set, the
key octets are interpreted as UTF-8, otherwise they are interpreted as Latin-1. "hash" is a
precomputed hash of the key string, or zero if it has not been precomputed.
"value" is the scalar value to store for this key. "value" is copied by this function, which
thus does not take ownership of any reference to it, and 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.
COPHH * cophh_store_pvn(COPHH *cophh, const char *keypv,
STRLEN keylen, U32 hash,
SV *value, U32 flags)
cophh_store_pvs
NOTE: this function is experimental and may change or be removed without notice.
Like "cophh_store_pvn", but takes a literal string instead of a string/length pair, and no
precomputed hash.
COPHH * cophh_store_pvs(const COPHH *cophh,
"literal string" key, SV *value,
U32 flags)
cophh_store_sv
NOTE: this function is experimental and may change or be removed without notice.
Like "cophh_store_pvn", but takes a Perl scalar instead of a string/length pair.
COPHH * cophh_store_sv(const COPHH *cophh, SV *key,
U32 hash, SV *value, U32 flags)
COP Hint Reading
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)
cop_hints_fetch_pv
Like "cop_hints_fetch_pvn", but takes a nul-terminated string instead of a string/length pair.
SV * cop_hints_fetch_pv(const COP *cop,
const char *key, U32 hash,
U32 flags)
cop_hints_fetch_pvn
Look up the hint entry in the cop "cop" with the key specified by "keypv" and "keylen". If
"flags" has the "COPHH_KEY_UTF8" bit set, the key octets are interpreted as UTF-8, otherwise they
are interpreted as Latin-1. "hash" is a precomputed hash of the key string, or zero if it has
not been precomputed. Returns a mortal scalar copy of the value associated with the key, or
&PL_sv_placeholder if there is no value associated with the key.
SV * cop_hints_fetch_pvn(const COP *cop,
const char *keypv,
STRLEN keylen, U32 hash,
U32 flags)
cop_hints_fetch_pvs
Like "cop_hints_fetch_pvn", but takes a literal string instead of a string/length pair, and no
precomputed hash.
SV * cop_hints_fetch_pvs(const COP *cop,
"literal string" key,
U32 flags)
cop_hints_fetch_sv
Like "cop_hints_fetch_pvn", but takes a Perl scalar instead of a string/length pair.
SV * cop_hints_fetch_sv(const COP *cop, SV *key,
U32 hash, U32 flags)
Custom Operators
custom_op_register
Register a custom op. See "Custom Operators" in perlguts.
NOTE: this function 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)
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.
NOTE: this function must be explicitly called as Perl_custom_op_xop with an aTHX_ parameter.
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, which)
XopENABLE
Reenable a member of the XOP which has been disabled.
void XopENABLE(XOP *xop, 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
retreive a "XOP *" from a "OP *", use the more efficient "XopENTRYCUSTOM" instead.
XopENTRY(XOP *xop, 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, 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, which, value)
XopFLAGS
Return the XOP's flags.
U32 XopFLAGS(XOP *xop)
CV Manipulation Functions
This section documents functions to manipulate CVs which are code-values, or 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
)
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 Uses "strlen" to get the length of "name", then calls "get_cvn_flags".
NOTE: the perl_ form of this function is deprecated.
CV* get_cv(const char* name, I32 flags)
get_cvn_flags
Returns 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.
NOTE: the perl_ form of this function is deprecated.
CV* get_cvn_flags(const char* name, STRLEN len,
I32 flags)
xsubpp" variables and internal functions
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.
I32 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;
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.
I32 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
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.
(whatever) RETVAL
ST Used to access elements on the XSUB's stack.
SV* ST(int ix)
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.
(whatever) 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.
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.
Debugging Utilities
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_packsubs
Dumps the optrees for all visible subroutines in "stash".
void dump_packsubs(const HV* stash)
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)
sv_dump Dumps the contents of an SV to the "STDERR" filehandle.
For an example of its output, see Devel::Peek.
void sv_dump(SV* sv)
Display and Dump functions
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.
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, const STRLEN max,
STRLEN * const escaped,
const 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)
Embedding Functions
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()
find_rundefsvoffset
DEPRECATED! It is planned to remove this function from a future release of Perl. Do not use it
for new code; remove it from existing code.
Until the lexical $_ feature was removed, this function would find the position of the lexical $_
in the pad of the currently-executing function and return the offset in the current pad, or
"NOT_IN_PAD".
Now it always returns "NOT_IN_PAD".
NOTE: the perl_ form of this function is deprecated.
PADOFFSET find_rundefsvoffset()
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
Loads 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".
void load_module(U32 flags, SV* name, SV* ver, ...)
newPADNAMELIST
NOTE: this function 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: this function 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 "PADNAMEt_OUTER" flag already set.
PADNAME * newPADNAMEouter(PADNAME *outer)
newPADNAMEpvn
NOTE: this function 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, 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, 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
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: this function 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: this function 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: this function 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_setsv
Set the value at offset "po" in the current (compiling or executing) pad. Use the macro
"PAD_SETSV()" rather than calling this function directly.
void pad_setsv(PADOFFSET po, SV *sv)
pad_sv Get the value at offset "po" in the current (compiling or executing) pad. Use macro "PAD_SV"
instead of calling this function directly.
SV * pad_sv(PADOFFSET po)
pad_tidy
NOTE: this function 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_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_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. A historical bug is preserved for the time being: if the Perl built-in "exit"
is called during this function's execution, with a type of exit entailing a zero exit code under
the host operating system's conventions, then this function returns zero rather than a non-zero
value. This bug, [perl #2754], leads to "perl_run" being called (and therefore "INIT" blocks and
the main program running) despite a call to "exit". It has been preserved because a popular
module-installing module has come to rely on it and needs time to be fixed. This issue is [perl
#132577], and the original bug is due to be fixed in Perl 5.30.
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)
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_ form of this function is deprecated.
void require_pv(const char* pv)
Exception Handling (simple) Macros
dXCPT Set up necessary local variables for exception handling. See "Exception Handling" in perlguts.
dXCPT;
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.
Functions in file pp_sort.c
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)
Functions in file scope.c
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)
Functions in file vutil.c
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)
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)
Gimme" Values
G_ARRAY Used to indicate list context. See "GIMME_V", "GIMME" and perlcall.
G_DISCARD
Indicates that arguments returned from a callback should be discarded. See perlcall.
G_EVAL Used to force a Perl "eval" wrapper around a callback. See perlcall.
GIMME A backward-compatible version of "GIMME_V" which can only return "G_SCALAR" or "G_ARRAY"; 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_ARRAY"
for void, scalar or list context, respectively. See perlcall for a usage example.
U32 GIMME_V
G_NOARGS
Indicates that no arguments are being sent to a callback. See perlcall.
G_SCALAR
Used to indicate scalar context. See "GIMME_V", "GIMME", and perlcall.
G_VOID Used to indicate void context. See "GIMME_V" and perlcall.
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_keyword_plugin
NOTE: this function 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".
GV Functions
A GV is a structure which corresponds to 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.
GvAV Return the AV from the GV.
AV* GvAV(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_fetchmeth
Like "gv_fetchmeth_pvn", but lacks a flags parameter.
GV* gv_fetchmeth(HV* stash, const char* name,
STRLEN len, I32 level)
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_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_fetchmeth_pv
Exactly like "gv_fetchmeth_pvn", but takes a nul-terminated string instead of a string/length
pair.
GV* gv_fetchmeth_pv(HV* stash, const char* name,
I32 level, U32 flags)
gv_fetchmeth_pvn
Returns the glob with the given "name" and a defined subroutine or "NULL". The glob lives in the
given "stash", or in the stashes accessible via @ISA and "UNIVERSAL::".
The argument "level" should be either 0 or -1. If "level==0", as a side-effect creates a glob
with the given "name" in the given "stash" which in the case of success contains an alias for the
subroutine, and sets up caching info for this glob.
The only significant values for "flags" are "GV_SUPER" and "SVf_UTF8".
"GV_SUPER" indicates that we want to look up the method in the superclasses of the "stash".
The GV returned from "gv_fetchmeth" 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.
GV* gv_fetchmeth_pvn(HV* stash, const char* name,
STRLEN len, 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_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_sv
Exactly like "gv_fetchmeth_pvn", but takes the name string in the form of an SV instead of a
string/length pair.
GV* gv_fetchmeth_sv(HV* stash, SV* namesv,
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)
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_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
SVf_UTF8
GV_NOADD_NOINIT
GV_NOINIT
GV_NOEXPAND
GV_ADDMG
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("literal string" 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.
SV* GvSV(GV* gv)
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)
Handy Values
Nullav Null AV pointer.
(deprecated - use "(AV *)NULL" instead)
Nullch Null character pointer. (No longer available when "PERL_CORE" is defined.)
Nullcv Null CV pointer.
(deprecated - use "(CV *)NULL" instead)
Nullhv Null HV pointer.
(deprecated - use "(HV *)NULL" instead)
Nullsv Null SV pointer. (No longer available when "PERL_CORE" is defined.)
Hash Manipulation Functions
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.
cop_fetch_label
NOTE: this function is experimental and may change or be removed without notice.
Returns the label attached to a cop. The flags pointer may be set to "SVf_UTF8" or 0.
const char * cop_fetch_label(COP *const cop,
STRLEN *len, U32 *flags)
cop_store_label
NOTE: this function 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.
void cop_store_label(COP *const cop,
const char *label, STRLEN len,
U32 flags)
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 and the
variable does not exist then "NULL" is returned.
NOTE: the perl_ form of this function is deprecated.
HV* get_hv(const char *name, I32 flags)
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_assert
Check that a hash is in an internally consistent state.
void hv_assert(HV *hv)
hv_bucket_ratio
NOTE: this function 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 the 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 *ohv)
hv_delete
Deletes a key/value pair in the hash. The value's SV is removed from the hash, made mortal, and
returned to the caller. 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. 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)
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
Returns a boolean indicating whether the specified hash key 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)
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
Returns the SV which corresponds to the specified key in the hash. 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. 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)
hv_fetchs
Like "hv_fetch", but takes a literal string instead of a string/length pair.
SV** hv_fetchs(HV* tb, "literal string" 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_fill Returns the number of hash buckets that happen to be in use.
This function is wrapped by the macro "HvFILL".
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 hv_fill(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_iternextsv
Performs an "hv_iternext", "hv_iterkey", and "hv_iterval" in one operation.
SV* hv_iternextsv(HV *hv, char **key, I32 *retlen)
hv_iternext_flags
NOTE: this function 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_iterval
Returns the value from the current position of the hash iterator. See "hv_iterkey".
SV* hv_iterval(HV *hv, HE *entry)
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.
STRLEN HvNAMELEN(HV *stash)
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
Stores an SV in a hash. The hash key is specified as "key" and 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.
The "hash" parameter is the precomputed hash value; if it is zero then Perl will compute it.
The return value 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 it can be
dereferenced to get the original "SV*". 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" 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)
hv_stores
Like "hv_store", but takes a literal string instead of a string/length pair and omits the hash
parameter.
SV** hv_stores(HV* tb, "literal string" 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()
Hook manipulation
These functions provide convenient and thread-safe means of manipulating hook variables.
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)
Lexer interface
This is the lower layer of the Perl parser, managing characters and tokens.
lex_bufutf8
NOTE: this function 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: this function 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: this function 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: this function 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: this function 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: this function 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: this function 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: this function 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: this function 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: this function 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: this function 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: this function 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("literal string" pv, U32 flags)
lex_stuff_sv
NOTE: this function 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: this function 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: this function 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: this function 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: this function 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: this function 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: this function 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: this function 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: this function 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: this function 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_termexpr
NOTE: this function 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: this function 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: this function 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: this function 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: this function 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.
wrap_keyword_plugin
NOTE: this function 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_plugin, 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
)
Locale-related functions and macros
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
Perl_langinfo
This 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".
Expanding on these:
• The reason it isn't quite a drop-in replacement is actually an advantage. The only
difference is that it returns "const char *", whereas plain "nl_langinfo()" returns "char *",
but you are (only by documentation) forbidden to write into the buffer. By declaring this
"const", the compiler enforces this restriction, so if it is violated, you know at
compilation time, rather than getting segfaults at runtime.
• It delivers 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.)
• The system function it replaces can have its static return buffer trashed, not only by a
subesequent call to that function, but by a "freelocale", "setlocale", or other locale
change. The returned buffer of this function is not changed until the next call to it, so
the buffer is never in a trashed state.
• Its return buffer is per-thread, so it also is never overwritten by a call to this function
from another thread; unlike the function it replaces.
• But most importantly, it works on systems that don't have "nl_langinfo", such as Windows,
hence makes your code more portable. Of the fifty-some possible items specified by the POSIX
2008 standard, <http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/langinfo.h.html>,
only one is completely unimplemented, though on non-Windows platforms, another significant
one is also not implemented). It uses 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; ""
is returned for those not available on your system.
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" will be overwritten.
This means you must save that buffer's contents if you need to access them after a call to
this function. (But note that you might not want to be using "localeconv()" directly anyway,
because of issues like the ones listed in the second item of this list (above) for
"RADIXCHAR" and "THOUSEP". You can use the methods given in perlcall to call "localeconv" in
POSIX and avoid all the issues, but then you have a hash to unpack).
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.
When using "Perl_langinfo" on systems that don't have a native "nl_langinfo()", you must
#include "perl_langinfo.h"
before the "perl.h" "#include". You can replace your "langinfo.h" "#include" with this one.
(Doing it this way keeps out the symbols that plain "langinfo.h" would try to import into the
namespace for code that doesn't need it.)
The original impetus for "Perl_langinfo()" was so that code that needs to find out the current
currency symbol, floating point radix character, or digit grouping separator can use, on all
systems, the simpler and more thread-friendly "nl_langinfo" API instead of localeconv(3) which is
a pain to make thread-friendly. For other fields returned by "localeconv", it is better to use
the methods given in perlcall to call "POSIX::localeconv()", which is thread-friendly.
const char* Perl_langinfo(const nl_item item)
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.
"Perl_setlocale" should not be used to change the locale except on systems where the predefined
variable "${^SAFE_LOCALES}" is 1. On some such systems, the system "setlocale()" is ineffective,
returning the wrong information, and failing to actually change the locale. "Perl_setlocale",
however works properly in all circumstances.
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()
STORE_LC_NUMERIC_FORCE_TO_UNDERLYING
This is used by XS code that 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.
void STORE_LC_NUMERIC_SET_TO_NEEDED()
switch_to_global_locale
On systems without locale support, or on typical single-threaded builds, or on platforms that do
not support per-thread locale operations, this function does nothing. On such systems that do
have locale support, only a locale global to the whole program is available.
On multi-threaded builds on systems that do have per-thread locale operations, this function
converts the thread it is running in to use the global locale. This is for code that has not yet
or cannot be updated to handle multi-threaded locale operation. As long as only a single thread
is so-converted, everything works fine, as all the other threads continue to ignore the global
one, so only this thread looks at it.
However, on Windows systems this isn't quite true prior to Visual Studio 15, at which point
Microsoft fixed a bug. A race can occur if you use the following operations on earlier Windows
platforms:
POSIX::localeconv
I18N::Langinfo, items "CRNCYSTR" and "THOUSEP"
"Perl_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 using the Windows API functions
"GetNumberFormat" and "GetCurrencyFormat"; patches welcome.
Without this function call, threads that use the setlocale(3) system function will not work
properly, as all the locale-sensitive functions will look at the per-thread locale, and
"setlocale" will have no effect on this thread.
Perl code should convert 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.
Non-Perl libraries, such as "gtk", that call the system "setlocale" can continue to work if this
function is called before transferring control to the library.
Upon return from the code that needs to use the global locale, "sync_locale()" should be called
to restore the safe multi-thread operation.
void switch_to_global_locale()
sync_locale
"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 system
setlocale(3) should be avoided. Nevertheless, certain non-Perl libraries called from XS, such as
"Gtk" do so, and this can't be changed. When the locale is changed by XS code that didn't use
"Perl_setlocale", Perl needs to be told that the locale has changed. Use this function to do so,
before returning to Perl.
The return value is a boolean: TRUE if the global locale at the time of call was in effect; and
FALSE if a per-thread locale was in effect. This can be used by the caller that needs to restore
things as-they-were to decide whether or not to call "Perl_switch_to_global_locale".
bool sync_locale()
Magical Functions
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)
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_length
DEPRECATED! It is planned to remove this function from a future release of Perl. Do not use it
for new code; remove it from existing code.
Reports on the SV's length in bytes, calling length magic if available, but does not set the UTF8
flag on "sv". It will fall back to 'get' magic if there is no 'length' magic, but with no
indication as to whether it called 'get' magic. It assumes "sv" is a "PVMG" or higher. Use
"sv_len()" instead.
U32 mg_length(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)
SvGETMAGIC
Invokes "mg_get" on an SV if it has 'get' magic. For example, this will call "FETCH" on a tied
variable. This macro evaluates its argument more than once.
void SvGETMAGIC(SV* sv)
SvLOCK Arranges for a mutual exclusion lock to be obtained on "sv" if a suitable module has been loaded.
void SvLOCK(SV* sv)
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
Like "SvSetSV", but does any set magic required afterwards.
void SvSetMagicSV(SV* dsv, SV* ssv)
SvSetMagicSV_nosteal
Like "SvSetSV_nosteal", but does any set magic required afterwards.
void SvSetMagicSV_nosteal(SV* dsv, SV* ssv)
SvSetSV Calls "sv_setsv" if "dsv" is not the same as "ssv". May evaluate arguments more than once. Does
not handle 'set' magic on the destination SV.
void SvSetSV(SV* dsv, SV* ssv)
SvSetSV_nosteal
Calls a non-destructive version of "sv_setsv" if "dsv" is not the same as "ssv". May evaluate
arguments more than once.
void SvSetSV_nosteal(SV* dsv, SV* ssv)
SvSHARE Arranges for "sv" to be shared between threads if a suitable module has been loaded.
void SvSHARE(SV* sv)
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)
SvUNLOCK
Releases a mutual exclusion lock on "sv" if a suitable module has been loaded.
void SvUNLOCK(SV* sv)
Memory Management
Copy 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".
void Copy(void* src, void* dest, int nitems, type)
CopyD Like "Copy" but returns "dest". Useful for encouraging compilers to tail-call optimise.
void * CopyD(void* src, void* dest, int nitems, type)
Move 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".
void Move(void* src, void* dest, int nitems, type)
MoveD Like "Move" but returns "dest". Useful for encouraging compilers to tail-call optimise.
void * MoveD(void* src, void* dest, int nitems, type)
Newx 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)
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 The XSUB-writer's interface to the C "malloc" 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)
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)
Renew 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)
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)
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". 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 "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, I32 len)
savepvs Like "savepvn", but takes a literal string instead of a string/length pair.
char* savepvs("literal string" s)
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" s)
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)
StructCopy
This is an architecture-independent macro to copy one structure to another.
void StructCopy(type *src, type *dest, type)
Zero 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.
void Zero(void* dest, int nitems, type)
ZeroD Like "Zero" but returns dest. Useful for encouraging compilers to tail-call optimise.
void * ZeroD(void* dest, int nitems, type)
Miscellaneous Functions
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)
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)
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)
form Takes a sprintf-style format pattern and conventional (non-SV) arguments and returns the
formatted string.
(char *) Perl_form(pTHX_ const char* pat, ...)
can be used any place a string (char *) is required:
char * s = Perl_form("%d.%d",major,minor);
Uses a single private buffer so if you want to format several strings you must explicitly copy
the earlier strings away (and free the copies when you are done).
char* form(const char* pat, ...)
getcwd_sv
Fill "sv" with current working directory
int getcwd_sv(SV* sv)
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)
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)
is_safe_syscall
Test that the given "pv" doesn't contain any internal "NUL" characters. If it does, set "errno"
to "ENOENT", optionally warn, and return FALSE.
Return TRUE if the name is safe.
Used by the "IS_SAFE_SYSCALL()" macro.
bool is_safe_syscall(const char *pv, STRLEN len,
const char *what,
const char *op_name)
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 zero if equal, or non-zero if
non-equal.
bool memEQ(char* s1, char* s2, STRLEN len)
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 zero if non-equal, or non-zero
if equal.
bool memNE(char* s1, char* s2, STRLEN len)
mess Take a sprintf-style format pattern and 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".
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 * mess(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)
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_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" characters. 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" characters 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)
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" characters. It will will never
attempt to address more than "maxlen" characters, 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 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)
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(char * big, char * bigend, char * little,
char * little_end)
PERL_SYS_INIT
Provides system-specific tune up of the C runtime environment necessary to run Perl interpreters.
This should be called only once, before creating any Perl interpreters.
void PERL_SYS_INIT(int *argc, char*** argv)
PERL_SYS_INIT3
Provides system-specific tune up of the C runtime environment necessary to run Perl interpreters.
This should be called only once, before creating any Perl interpreters.
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()
quadmath_format_needed
"quadmath_format_needed()" returns true if the "format" string seems to contain at least one non-
Q-prefixed "%[efgaEFGA]" format specifier, or returns false otherwise.
The format specifier detection is not complete printf-syntax detection, but it should catch most
common cases.
If true is returned, those arguments should in theory be processed with "quadmath_snprintf()",
but in case there is more than one such format specifier (see "quadmath_format_single"), and if
there is anything else beyond that one (even just a single byte), they cannot be processed
because "quadmath_snprintf()" is very strict, accepting only one format spec, and nothing else.
In this case, the code should probably fail.
bool quadmath_format_needed(const char* format)
quadmath_format_single
"quadmath_snprintf()" is very strict about its "format" string and will fail, returning -1, if
the format is invalid. It accepts exactly one format spec.
"quadmath_format_single()" checks that the intended single spec looks sane: begins with "%", has
only one "%", ends with "[efgaEFGA]", and has "Q" before it. This is not a full "printf syntax
check", just the basics.
Returns the format if it is valid, NULL if not.
"quadmath_format_single()" can and will actually patch in the missing "Q", if necessary. In this
case it will return the modified copy of the format, which the caller will need to free.
See also "quadmath_format_needed".
const char* quadmath_format_single(const char* format)
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*)
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(char * big, char * bigend,
char * little, char * little_end)
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)
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)
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)
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)
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)
MRO Functions
These functions are related to the method resolution order of perl classes
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*.
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_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.
void mro_register(const struct mro_alg *mro)
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;
Numeric functions
grok_bin
converts a string representing a binary number to numeric form.
On entry "start" and *len 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 the first
invalid character. Unless "PERL_SCAN_SILENT_ILLDIGIT" is set in *flags, encountering an invalid
character will also trigger a warning. On return *len 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 the value to *result (or the
value 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 the binary
number may use "_" characters to separate digits.
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 the first
invalid character. Unless "PERL_SCAN_SILENT_ILLDIGIT" is set in *flags, encountering an invalid
character will also trigger a warning. On return *len 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 the value to *result (or the
value 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 the hex number
may use "_" characters to separate digits.
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
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 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 the first
invalid character. Unless "PERL_SCAN_SILENT_ILLDIGIT" is set in *flags, encountering an 8 or 9
will also trigger a warning. On return *len 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 the value to *result (or the
value is discarded if "result" is "NULL").
If "PERL_SCAN_ALLOW_UNDERSCORES" is set in *flags then the octal number may use "_" characters to
separate digits.
UV grok_oct(const char* start, STRLEN* len_p,
I32* flags, NV *result)
isinfnan
"Perl_isinfnan()" is 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_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 Strod() may be used instead.
NV my_strtod(const char * const s, char ** e)
Perl_signbit
NOTE: this function 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)
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)
Obsolete backwards compatibility functions
Some of these are also deprecated. You can exclude these from your compiled Perl by adding this option
to Configure: "-Accflags='-DNO_MATHOMS'"
custom_op_desc
Return the description of a given custom op. This was once used by the "OP_DESC" macro, but is
no longer: it has only been kept for compatibility, and should not be used.
const char * custom_op_desc(const OP *o)
custom_op_name
Return the name for a given custom op. This was once used by the "OP_NAME" macro, but is no
longer: it has only been kept for compatibility, and should not be used.
const char * custom_op_name(const OP *o)
gv_fetchmethod
See "gv_fetchmethod_autoload".
GV* gv_fetchmethod(HV* stash, const char* name)
is_utf8_char
DEPRECATED! It is planned to remove this function from a future release of Perl. Do not use it
for new code; remove it from existing code.
Tests if some arbitrary number of bytes begins in a valid UTF-8 character. Note that an
INVARIANT (i.e. ASCII on non-EBCDIC machines) character is a valid UTF-8 character. The actual
number of bytes in the UTF-8 character will be returned if it is valid, otherwise 0.
This function is deprecated due to the possibility that malformed input could cause reading
beyond the end of the input buffer. Use "isUTF8_CHAR" instead.
STRLEN is_utf8_char(const U8 *s)
is_utf8_char_buf
This is identical to the macro "isUTF8_CHAR".
STRLEN is_utf8_char_buf(const U8 *buf,
const U8 *buf_end)
pack_cat
The engine implementing "pack()" Perl function. Note: parameters "next_in_list" and "flags" are
not used. This call should not be used; use "packlist" instead.
void pack_cat(SV *cat, const char *pat,
const char *patend, SV **beglist,
SV **endlist, SV ***next_in_list,
U32 flags)
pad_compname_type
Looks up the type of the lexical variable at position "po" in the currently-compiling pad. If
the variable is typed, the stash of the class to which it is typed is returned. If not, "NULL"
is returned.
HV * pad_compname_type(PADOFFSET po)
sv_2pvbyte_nolen
Return a pointer to the byte-encoded representation of the SV. May cause the SV to be downgraded
from UTF-8 as a side-effect.
Usually accessed via the "SvPVbyte_nolen" macro.
char* sv_2pvbyte_nolen(SV* sv)
sv_2pvutf8_nolen
Return a pointer to the UTF-8-encoded representation of the SV. May cause the SV to be upgraded
to UTF-8 as a side-effect.
Usually accessed via the "SvPVutf8_nolen" macro.
char* sv_2pvutf8_nolen(SV* sv)
sv_2pv_nolen
Like "sv_2pv()", but doesn't return the length too. You should usually use the macro wrapper
"SvPV_nolen(sv)" instead.
char* sv_2pv_nolen(SV* sv)
sv_catpvn_mg
Like "sv_catpvn", but also handles 'set' magic.
void sv_catpvn_mg(SV *sv, const char *ptr,
STRLEN len)
sv_catsv_mg
Like "sv_catsv", but also handles 'set' magic.
void sv_catsv_mg(SV *dsv, SV *ssv)
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_iv A private implementation of the "SvIVx" macro for compilers which can't cope with complex macro
expressions. Always use the macro instead.
IV sv_iv(SV* sv)
sv_nolocking
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
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_nv A private implementation of the "SvNVx" macro for compilers which can't cope with complex macro
expressions. Always use the macro instead.
NV sv_nv(SV* sv)
sv_pv Use the "SvPV_nolen" macro instead
char* sv_pv(SV *sv)
sv_pvbyte
Use "SvPVbyte_nolen" instead.
char* sv_pvbyte(SV *sv)
sv_pvbyten
A private implementation of the "SvPVbyte" macro for compilers which can't cope with complex
macro expressions. Always use the macro instead.
char* sv_pvbyten(SV *sv, STRLEN *lp)
sv_pvn A private implementation of the "SvPV" macro for compilers which can't cope with complex macro
expressions. Always use the macro instead.
char* sv_pvn(SV *sv, STRLEN *lp)
sv_pvutf8
Use the "SvPVutf8_nolen" macro instead
char* sv_pvutf8(SV *sv)
sv_pvutf8n
A private implementation of the "SvPVutf8" macro for compilers which can't cope with complex
macro expressions. Always use the macro instead.
char* sv_pvutf8n(SV *sv, STRLEN *lp)
sv_taint
Taint an SV. Use "SvTAINTED_on" instead.
void sv_taint(SV* sv)
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_usepvn
Tells an SV to use "ptr" to find its string value. Implemented by calling "sv_usepvn_flags" with
"flags" of 0, hence does not handle 'set' magic. See "sv_usepvn_flags".
void sv_usepvn(SV* sv, char* ptr, STRLEN len)
sv_usepvn_mg
Like "sv_usepvn", but also handles 'set' magic.
void sv_usepvn_mg(SV *sv, char *ptr, STRLEN len)
sv_uv A private implementation of the "SvUVx" macro for compilers which can't cope with complex macro
expressions. Always use the macro instead.
UV sv_uv(SV* sv)
unpack_str
The engine implementing "unpack()" Perl function. Note: parameters "strbeg", "new_s" and "ocnt"
are not used. This call should not be used, use "unpackstring" instead.
SSize_t unpack_str(const char *pat, const char *patend,
const char *s, const char *strbeg,
const char *strend, char **new_s,
I32 ocnt, U32 flags)
utf8_to_uvuni
DEPRECATED! It is planned to remove this function from a future release of Perl. Do not use it
for new code; remove it from existing code.
Returns the Unicode 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 one reason why this function is
deprecated. The other is that only in extremely limited circumstances should the Unicode versus
native code point be of any interest to you. See "utf8_to_uvuni_buf" for alternatives.
If "s" points to one of the detected malformations, and UTF8 warnings are enabled, zero is
returned and *retlen is set (if "retlen" doesn't point to 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_uvuni(const U8 *s, STRLEN *retlen)
Optree construction
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)
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)
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 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)
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.
OP * newLISTOP(I32 type, I32 flags, OP *first,
OP *last)
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 type, 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 *first)
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 type, 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 *listval)
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)
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)
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)
Optree Manipulation Functions
alloccopstash
NOTE: this function 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)
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
)
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)
newCONSTSUB
Behaves like "newCONSTSUB_flags", except that "name" is nul-terminated rather than of counted
length, and no flags are set. (This means that "name" is always interpreted as Latin-1.)
CV * newCONSTSUB(HV *stash, const char *name, SV *sv)
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 of length "len" bytes giving a sigilless symbol
name, in UTF-8 if "flags" has the "SVf_UTF8" bit set and in Latin-1 otherwise. 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.
"flags" should not have bits set other than "SVf_UTF8".
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_flags(HV *stash, const char *name,
STRLEN len, U32 flags, SV *sv)
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.
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_ARRAY", 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 type, I32 flags, OP *o)
OP_DESC Return a short description of the provided OP.
const char * OP_DESC(OP *o)
op_free Free an op. Only use this when an op is no longer linked to from any optree.
void op_free(OP *o)
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: this function 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: this function 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 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)
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)
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)
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: this function 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("literal string" name,
U32 flags, HV *typestash,
HV *ourstash)
PadARRAY
NOTE: this function 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("literal string" name,
U32 flags)
PadlistARRAY
NOTE: this function 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: this function 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: this function is experimental and may change or be removed without notice.
The names associated with pad entries.
PADNAMELIST * PadlistNAMES(PADLIST padlist)
PadlistNAMESARRAY
NOTE: this function is experimental and may change or be removed without notice.
The C array of pad names.
PADNAME ** PadlistNAMESARRAY(PADLIST padlist)
PadlistNAMESMAX
NOTE: this function is experimental and may change or be removed without notice.
The index of the last pad name.
SSize_t PadlistNAMESMAX(PADLIST padlist)
PadlistREFCNT
NOTE: this function 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: this function is experimental and may change or be removed without notice.
The index of the last pad entry.
SSize_t PadMAX(PAD pad)
PadnameLEN
NOTE: this function is experimental and may change or be removed without notice.
The length of the name.
STRLEN PadnameLEN(PADNAME pn)
PadnamelistARRAY
NOTE: this function is experimental and may change or be removed without notice.
The C array of pad names.
PADNAME ** PadnamelistARRAY(PADNAMELIST pnl)
PadnamelistMAX
NOTE: this function is experimental and may change or be removed without notice.
The index of the last pad name.
SSize_t PadnamelistMAX(PADNAMELIST pnl)
PadnamelistREFCNT
NOTE: this function 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: this function 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: this function 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: this function 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: this function is experimental and may change or be removed without notice.
Lowers the reference count of the pad name.
void PadnameREFCNT_dec(PADNAME pn)
PadnameSV
NOTE: this function is experimental and may change or be removed without notice.
Returns the pad name as a mortal SV.
SV * PadnameSV(PADNAME pn)
PadnameUTF8
NOTE: this function 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: this function 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: this function 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: this function 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)".)
Per-Interpreter Variables
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.
HV* PL_modglobal
PL_na A convenience variable which is typically used with "SvPV" when one doesn't care about the length
of the string. 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
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.
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.
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.
peep_t PL_rpeepp
PL_sv_no
This is the "false" SV. See "PL_sv_yes". Always refer to this as &PL_sv_no.
SV PL_sv_no
PL_sv_undef
This is the "undef" SV. Always refer to this as &PL_sv_undef.
SV PL_sv_undef
PL_sv_yes
This is the "true" SV. 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
REGEXP Functions
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)
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;
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)
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)
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)
ORIGMARK
The original stack mark for the XSUB. See "dORIGMARK".
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)
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;
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;
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)
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)
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_mYES
Place &PL_sv_yes into the specified position "pos" on the stack.
void XST_mYES(int pos)
SV Flags
SVt_INVLIST
Type flag for scalars. See "svtype".
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_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
These are most easily explained from the bottom up.
"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 any of those or a double. "SVt_PV" can only hold "undef" or a string.
"SVt_PVIV" is a superset of "SVt_PV" and "SVt_IV". "SVt_PVNV" is similar. "SVt_PVMG" can hold
anything "SVt_PVNV" can hold, but it can, but does not have to, be blessed or magical.
SV Manipulation Functions
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:
Perl_croak(aTHX_ "Usage: %" SVf "::%" SVf "(%s)", "ouch" "awk",
"eee_yow");
void croak_xs_usage(const CV *const cv,
const char *const params)
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_ form of this function is deprecated.
SV* get_sv(const char *name, I32 flags)
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)
newRV_inc
Creates an RV wrapper for an SV. The reference count for the original SV is incremented.
SV* newRV_inc(SV* 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)
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)
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: this function 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".
SV* newSVpvf(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" s)
newSVpvs_flags
Like "newSVpvn_flags", but takes a literal string instead of a string/length pair.
SV* newSVpvs_flags("literal string" s, 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" s)
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 Creates a new SV which is an exact duplicate of the original SV. (Uses "sv_setsv".)
SV* newSVsv(SV *const old)
newSVsv_nomg
Like "newSVsv" but does not process get magic.
SV* newSVsv_nomg(SV *const old)
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)
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)
sv_2bool
This macro is only used by "sv_true()" or its macro equivalent, and only if the latter's argument
is neither "SvPOK", "SvIOK" nor "SvNOK". It calls "sv_2bool_flags" with the "SV_GMAGIC" flag.
bool sv_2bool(SV *const sv)
sv_2bool_flags
This function is only used by "sv_true()" and friends, and only if the latter's argument is
neither "SvPOK", "SvIOK" nor "SvNOK". If the flags contain "SV_GMAGIC", then it does an
"mg_get()" first.
bool sv_2bool_flags(SV *sv, I32 flags)
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_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)
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)
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_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)
sv_2pvbyte
Return a pointer to the byte-encoded representation of the SV, and set *lp to its length. May
cause the SV to be downgraded from UTF-8 as a side-effect.
Usually accessed via the "SvPVbyte" macro.
char* sv_2pvbyte(SV *sv, STRLEN *const lp)
sv_2pvutf8
Return a pointer to the UTF-8-encoded representation of the SV, and set *lp to its length. May
cause the SV to be upgraded to UTF-8 as a side-effect.
Usually accessed via the "SvPVutf8" macro.
char* sv_2pvutf8(SV *sv, STRLEN *const lp)
sv_2pv_flags
Returns a pointer to the string value of an SV, and sets *lp to its length. If flags has the
"SV_GMAGIC" bit set, does an "mg_get()" first. Coerces "sv" to a string if necessary. Normally
invoked via the "SvPV_flags" macro. "sv_2pv()" and "sv_2pv_nomg" usually end up here too.
char* sv_2pv_flags(SV *const sv, STRLEN *const lp,
const I32 flags)
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)
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)
sv_catpv
Concatenates the "NUL"-terminated string 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. Handles 'get' magic,
but not 'set' magic. See "sv_catpv_mg".
void sv_catpv(SV *const sv, const char* ptr)
sv_catpvf
Processes its arguments like "sprintf", and appends the formatted output to an SV. As with
"sv_vcatpvfn" called with a non-null C-style variable argument list, argument reordering is not
supported. 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. Handles 'get' magic, but not 'set' magic. See "sv_catpvf_mg". 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.
void sv_catpvf(SV *const sv, const char *const pat,
...)
sv_catpvf_mg
Like "sv_catpvf", but also handles 'set' magic.
void sv_catpvf_mg(SV *const sv,
const char *const pat, ...)
sv_catpvn
Concatenates the string onto the end of the string which is in the SV. "len" indicates number of
bytes to copy. If the SV has the UTF-8 status set, then the bytes appended should be valid
UTF-8. Handles 'get' magic, but not 'set' magic. See "sv_catpvn_mg".
void sv_catpvn(SV *dsv, const char *sstr, STRLEN len)
sv_catpvn_flags
Concatenates the string onto the end of the string which is in the SV. The "len" indicates
number of bytes to copy.
By default, 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. One can force the appended string to be interpreted as UTF-8 by
supplying the "SV_CATUTF8" flag, and as bytes by supplying the "SV_CATBYTES" flag; the SV or the
string appended will be upgraded to UTF-8 if necessary.
If "flags" has the "SV_SMAGIC" bit set, will "mg_set" on "dsv" afterwards if appropriate.
"sv_catpvn" and "sv_catpvn_nomg" are implemented in terms of this function.
void sv_catpvn_flags(SV *const dstr,
const char *sstr,
const STRLEN len,
const I32 flags)
sv_catpvn_nomg
Like "sv_catpvn" but doesn't process magic.
void sv_catpvn_nomg(SV* sv, const char* ptr,
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" s)
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" s,
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" s)
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" s)
sv_catpv_flags
Concatenates the "NUL"-terminated string 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. If "flags" has the
"SV_SMAGIC" bit set, will "mg_set" on the modified SV if appropriate.
void sv_catpv_flags(SV *dstr, const char *sstr,
const I32 flags)
sv_catpv_mg
Like "sv_catpv", but also handles 'set' magic.
void sv_catpv_mg(SV *const sv, const char *const ptr)
sv_catpv_nomg
Like "sv_catpv" but doesn't process magic.
void sv_catpv_nomg(SV* sv, const char* ptr)
sv_catsv
Concatenates the string from SV "ssv" onto the end of the string in SV "dsv". If "ssv" is null,
does nothing; otherwise modifies only "dsv". Handles 'get' magic on both SVs, but no 'set'
magic. See "sv_catsv_mg" and "sv_catsv_nomg".
void sv_catsv(SV *dstr, SV *sstr)
sv_catsv_flags
Concatenates the string from SV "ssv" onto the end of the string in SV "dsv". If "ssv" is null,
does nothing; otherwise modifies only "dsv". If "flags" has the "SV_GMAGIC" bit set, will call
"mg_get" on both SVs if appropriate. If "flags" has the "SV_SMAGIC" bit set, "mg_set" will be
called on the modified SV afterward, if appropriate. "sv_catsv", "sv_catsv_nomg", and
"sv_catsv_mg" are implemented in terms of this function.
void sv_catsv_flags(SV *const dsv, SV *const ssv,
const I32 flags)
sv_catsv_nomg
Like "sv_catsv" but doesn't process magic.
void sv_catsv_nomg(SV* dsv, SV* ssv)
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 "sv_free()" (or its macro wrapper
"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
Copies a stringified representation of the source SV into the destination SV. Automatically
performs any necessary "mg_get" and coercion of numeric values into strings. Guaranteed to
preserve "UTF8" flag even from overloaded objects. Similar in nature to "sv_2pv[_flags]" but
operates directly on an SV instead of just the string. Mostly uses "sv_2pv_flags" to do its
work, except when that would lose the UTF-8'ness of the PV.
void sv_copypv(SV *const dsv, SV *const ssv)
sv_copypv_flags
Implementation of "sv_copypv" and "sv_copypv_nomg". Calls get magic iff flags has the
"SV_GMAGIC" bit set.
void sv_copypv_flags(SV *const dsv, SV *const ssv,
const I32 flags)
sv_copypv_nomg
Like "sv_copypv", but doesn't invoke get magic first.
void sv_copypv_nomg(SV *const dsv, SV *const ssv)
SvCUR Returns the length of the string which is in the SV. See "SvLEN".
STRLEN SvCUR(SV* sv)
SvCUR_set
Set the current length of the string which is in the SV. See "SvCUR" and "SvIV_set">.
void SvCUR_set(SV* sv, STRLEN len)
sv_dec Auto-decrement of the value in the SV, doing string to numeric conversion if necessary. Handles
'get' magic and operator overloading.
void sv_dec(SV *const sv)
sv_dec_nomg
Auto-decrement of the value in the SV, doing string to numeric conversion if necessary. Handles
operator overloading. Skips handling 'get' magic.
void sv_dec_nomg(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_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.
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 Returns a boolean indicating whether the strings in the two SVs are identical. Is UTF-8 and
'use bytes' aware, handles get magic, and will coerce its args to strings if necessary.
I32 sv_eq(SV* sv1, SV* sv2)
sv_eq_flags
Returns a boolean indicating whether the strings in the two SVs are identical. Is UTF-8 and
'use bytes' aware and coerces its args to strings if necessary. If the flags has the "SV_GMAGIC"
bit set, it handles get-magic, too.
I32 sv_eq_flags(SV* sv1, SV* sv2, const U32 flags)
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_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)
sv_get_backrefs
NOTE: this function 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)
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)
sv_grow Expands the character buffer in the SV. If necessary, uses "sv_unref" and upgrades the SV to
"SVt_PV". Returns a pointer to the character buffer. Use the "SvGROW" wrapper instead.
char* sv_grow(SV *const sv, STRLEN newlen)
sv_inc Auto-increment of the value in the SV, doing string to numeric conversion if necessary. Handles
'get' magic and operator overloading.
void sv_inc(SV *const sv)
sv_inc_nomg
Auto-increment of the value in the SV, doing string to numeric conversion if necessary. Handles
operator overloading. Skips handling 'get' magic.
void sv_inc_nomg(SV *const sv)
sv_insert
Inserts and/or replaces 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". Handles get magic.
void sv_insert(SV *const bigstr, const STRLEN offset,
const STRLEN len,
const char *const little,
const STRLEN littlelen)
sv_insert_flags
Same as "sv_insert", but the extra "flags" are passed to the "SvPV_force_flags" that applies to
"bigstr".
void sv_insert_flags(SV *const bigstr,
const STRLEN offset,
const STRLEN len,
const char *little,
const STRLEN littlelen,
const U32 flags)
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
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; use "sv_derived_from" to verify an inheritance relationship.
int sv_isa(SV* sv, const char *const name)
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 Coerces the given SV to IV and returns 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).
See "SvIVx" for a version which guarantees to evaluate "sv" only once.
IV SvIV(SV* sv)
SvIV_nomg
Like "SvIV" but doesn't process magic.
IV SvIV_nomg(SV* sv)
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)
SvIVx Coerces the given SV to IV and returns 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).
This form guarantees to evaluate "sv" only once. Only use this if "sv" is an expression with
side effects, otherwise use the more efficient "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
Returns the number of characters in the string in an SV, counting wide UTF-8 bytes as a single
character. Handles magic and type coercion.
STRLEN sv_len_utf8(SV *const 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_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_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()
sv_newref
Increment an SV's reference count. Use the "SvREFCNT_inc()" wrapper instead.
SV* sv_newref(SV *const sv)
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)
SvNV Coerces the given SV to NV and returns 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).
See "SvNVx" for a version which guarantees to evaluate "sv" only once.
NV SvNV(SV* sv)
SvNV_nomg
Like "SvNV" but doesn't process magic.
NV SvNV_nomg(SV* sv)
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)
SvNVx Coerces the given SV to NV and returns 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).
This form guarantees to evaluate "sv" only once. Only use this if "sv" is an expression with
side effects, otherwise use the more efficient "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_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 Returns a pointer to the string in the SV, or a stringified form of the SV if the SV does not
contain a string. The SV may cache the stringified version becoming "SvPOK". Handles 'get'
magic. The "len" variable will be set to the length of the string (this is a macro, so don't use
&len). See also "SvPVx" for a version which guarantees to evaluate "sv" only once.
Note that there is no guarantee that the return value of "SvPV()" is equal to "SvPVX(sv)", or
that "SvPVX(sv)" contains valid data, or that successive calls to "SvPV(sv)" 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".
char* SvPV(SV* sv, STRLEN len)
SvPVbyte
Like "SvPV", but converts "sv" to byte representation first if necessary.
char* SvPVbyte(SV* sv, STRLEN len)
SvPVbyte_force
Like "SvPV_force", but converts "sv" to byte representation first if necessary.
char* SvPVbyte_force(SV* sv, STRLEN len)
SvPVbyte_nolen
Like "SvPV_nolen", but converts "sv" to byte representation first if necessary.
char* SvPVbyte_nolen(SV* sv)
sv_pvbyten_force
The backend for the "SvPVbytex_force" macro. Always use the macro instead.
char* sv_pvbyten_force(SV *const sv, STRLEN *const lp)
SvPVbytex
Like "SvPV", but converts "sv" to byte representation first if necessary. Guarantees to evaluate
"sv" only once; use the more efficient "SvPVbyte" otherwise.
char* SvPVbytex(SV* sv, STRLEN len)
SvPVbytex_force
Like "SvPV_force", but converts "sv" to byte representation first if necessary. Guarantees to
evaluate "sv" only once; use the more efficient "SvPVbyte_force" otherwise.
char* SvPVbytex_force(SV* sv, STRLEN len)
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)
SvPV_force
Like "SvPV" but will force the SV into containing a string ("SvPOK"), and only a string
("SvPOK_only"), by hook or by crook. You need force if you are going to update the "SvPVX"
directly. Processes get magic.
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)".
char* SvPV_force(SV* sv, STRLEN len)
SvPV_force_nomg
Like "SvPV_force", but doesn't process get magic.
char* SvPV_force_nomg(SV* sv, STRLEN len)
SvPV_nolen
Like "SvPV" but doesn't set a length variable.
char* SvPV_nolen(SV* sv)
SvPV_nomg
Like "SvPV" but doesn't process magic.
char* SvPV_nomg(SV* sv, STRLEN len)
SvPV_nomg_nolen
Like "SvPV_nolen" but doesn't process magic.
char* SvPV_nomg_nolen(SV* sv)
sv_pvn_force
Get a sensible string out of the SV somehow. A private implementation of the "SvPV_force" macro
for compilers which can't cope with complex macro expressions. Always use the macro instead.
char* sv_pvn_force(SV* sv, STRLEN* lp)
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 I32 flags)
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)
SvPVutf8
Like "SvPV", but converts "sv" to UTF-8 first if necessary.
char* SvPVutf8(SV* sv, STRLEN len)
sv_pvutf8n_force
The backend for the "SvPVutf8x_force" macro. Always use the macro instead.
char* sv_pvutf8n_force(SV *const sv, STRLEN *const lp)
SvPVutf8x
Like "SvPV", but converts "sv" to UTF-8 first if necessary. Guarantees to evaluate "sv" only
once; use the more efficient "SvPVutf8" otherwise.
char* SvPVutf8x(SV* sv, STRLEN len)
SvPVutf8x_force
Like "SvPV_force", but converts "sv" to UTF-8 first if necessary. Guarantees to evaluate "sv"
only once; use the more efficient "SvPVutf8_force" otherwise.
char* SvPVutf8x_force(SV* sv, STRLEN len)
SvPVutf8_force
Like "SvPV_force", but converts "sv" to UTF-8 first if necessary.
char* SvPVutf8_force(SV* sv, STRLEN len)
SvPVutf8_nolen
Like "SvPV_nolen", but converts "sv" to UTF-8 first if necessary.
char* SvPVutf8_nolen(SV* sv)
SvPVX Returns 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 this macro unless the SV's type >= "SVt_PV".
This is also used to store the name of an autoloaded subroutine in an XS AUTOLOAD routine. See
"Autoloading with XSUBs" in perlguts.
char* SvPVX(SV* sv)
SvPVx A version of "SvPV" which guarantees to evaluate "sv" only once. Only use this if "sv" is an
expression with side effects, otherwise use the more efficient "SvPV".
char* SvPVx(SV* sv, STRLEN len)
SvREADONLY
Returns true if the argument is readonly, otherwise returns false. Exposed to 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
Decrements the reference count of the given SV. "sv" may be "NULL".
void SvREFCNT_dec(SV* sv)
SvREFCNT_dec_NN
Same as "SvREFCNT_dec", but 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.
void SvREFCNT_dec_NN(SV* sv)
SvREFCNT_inc
Increments the reference count of the given SV, returning the SV.
All of the following "SvREFCNT_inc"* macros are optimized versions of "SvREFCNT_inc", and can be
replaced with "SvREFCNT_inc".
SV* SvREFCNT_inc(SV* sv)
SvREFCNT_inc_NN
Same as "SvREFCNT_inc", but 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.
SV* SvREFCNT_inc_NN(SV* sv)
SvREFCNT_inc_simple
Same as "SvREFCNT_inc", but can only be used with expressions without side effects. Since we
don't have to store a temporary value, it's faster.
SV* SvREFCNT_inc_simple(SV* sv)
SvREFCNT_inc_simple_NN
Same as "SvREFCNT_inc_simple", but 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.
SV* SvREFCNT_inc_simple_NN(SV* sv)
SvREFCNT_inc_simple_void
Same as "SvREFCNT_inc_simple", but can only be used if you don't need the return value. The
macro doesn't need to return a meaningful value.
void SvREFCNT_inc_simple_void(SV* sv)
SvREFCNT_inc_simple_void_NN
Same as "SvREFCNT_inc", but can only be used if you 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.
void SvREFCNT_inc_simple_void_NN(SV* sv)
SvREFCNT_inc_void
Same as "SvREFCNT_inc", but can only be used if you don't need the return value. The macro
doesn't need to return a meaningful value.
void SvREFCNT_inc_void(SV* sv)
SvREFCNT_inc_void_NN
Same as "SvREFCNT_inc", but can only be used if you 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.
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_setiv
Copies an integer into the given SV, upgrading first if necessary. Does not handle 'set' magic.
See also "sv_setiv_mg".
void sv_setiv(SV *const sv, const IV num)
sv_setiv_mg
Like "sv_setiv", but also handles 'set' magic.
void sv_setiv_mg(SV *const sv, const IV i)
sv_setnv
Copies a double into the given SV, upgrading first if necessary. Does not handle 'set' magic.
See also "sv_setnv_mg".
void sv_setnv(SV *const sv, const NV num)
sv_setnv_mg
Like "sv_setnv", but also handles 'set' magic.
void sv_setnv_mg(SV *const sv, const NV num)
sv_setpv
Copies a string into an SV. The string must be terminated with a "NUL" character, and not
contain embeded "NUL"'s. Does not handle 'set' magic. See "sv_setpv_mg".
void sv_setpv(SV *const sv, const char *const ptr)
sv_setpvf
Works like "sv_catpvf" but copies the text into the SV instead of appending it. Does not handle
'set' magic. See "sv_setpvf_mg".
void sv_setpvf(SV *const sv, const char *const pat,
...)
sv_setpvf_mg
Like "sv_setpvf", but also handles 'set' magic.
void sv_setpvf_mg(SV *const sv,
const char *const pat, ...)
sv_setpviv
Copies an integer into the given SV, also updating its string value. Does not handle 'set'
magic. See "sv_setpviv_mg".
void sv_setpviv(SV *const sv, const IV num)
sv_setpviv_mg
Like "sv_setpviv", but also handles 'set' magic.
void sv_setpviv_mg(SV *const sv, const IV iv)
sv_setpvn
Copies a string (possibly containing embedded "NUL" characters) into an SV. The "len" parameter
indicates the number of bytes to be copied. If the "ptr" argument is NULL the SV will become
undefined. Does not handle 'set' magic. See "sv_setpvn_mg".
void sv_setpvn(SV *const sv, const char *const ptr,
const STRLEN len)
sv_setpvn_mg
Like "sv_setpvn", but also handles 'set' magic.
void sv_setpvn_mg(SV *const sv,
const char *const ptr,
const STRLEN len)
sv_setpvs
Like "sv_setpvn", but takes a literal string instead of a string/length pair.
void sv_setpvs(SV* sv, "literal string" s)
sv_setpvs_mg
Like "sv_setpvn_mg", but takes a literal string instead of a string/length pair.
void sv_setpvs_mg(SV* sv, "literal string" s)
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.
char * sv_setpv_bufsize(SV *const sv, const STRLEN cur,
const STRLEN len)
sv_setpv_mg
Like "sv_setpv", but also handles 'set' magic.
void sv_setpv_mg(SV *const sv, const char *const ptr)
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("literal string" s)
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_setsv
Copies the contents of the source SV "ssv" into the destination SV "dsv". The source SV may be
destroyed if it is mortal, so don't use this function if the source SV needs to be reused. Does
not handle 'set' magic on destination SV. Calls 'get' magic on source SV. Loosely speaking, it
performs a copy-by-value, obliterating any previous content of the destination.
You probably want to use one of the assortment of wrappers, such as "SvSetSV", "SvSetSV_nosteal",
"SvSetMagicSV" and "SvSetMagicSV_nosteal".
void sv_setsv(SV *dstr, SV *sstr)
sv_setsv_flags
Copies the contents of the source SV "ssv" into the destination SV "dsv". The source SV may be
destroyed if it is mortal, so don't use this function if the source SV needs to be reused. Does
not handle 'set' magic. Loosely speaking, it performs a copy-by-value, obliterating any previous
content of the destination. If the "flags" parameter has the "SV_GMAGIC" bit set, will "mg_get"
on "ssv" if appropriate, else not. If the "flags" parameter has the "SV_NOSTEAL" bit set then
the buffers of temps will not be stolen. "sv_setsv" and "sv_setsv_nomg" are implemented in terms
of this function.
You probably want to use one of the assortment of wrappers, such as "SvSetSV", "SvSetSV_nosteal",
"SvSetMagicSV" and "SvSetMagicSV_nosteal".
This is the primary function for copying scalars, and most other copy-ish functions and macros
use this underneath.
void sv_setsv_flags(SV *dstr, SV *sstr,
const I32 flags)
sv_setsv_mg
Like "sv_setsv", but also handles 'set' magic.
void sv_setsv_mg(SV *const dstr, SV *const sstr)
sv_setsv_nomg
Like "sv_setsv" but doesn't process magic.
void sv_setsv_nomg(SV* dsv, SV* ssv)
sv_setuv
Copies an unsigned integer into the given SV, upgrading first if necessary. Does not handle
'set' magic. See also "sv_setuv_mg".
void sv_setuv(SV *const sv, const UV num)
sv_setuv_mg
Like "sv_setuv", but also handles 'set' magic.
void sv_setuv_mg(SV *const sv, const UV u)
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)
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)
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)
sv_tainted
Test an SV for taintedness. Use "SvTAINTED" instead.
bool sv_tainted(SV *const 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)
SvTRUE Returns a boolean indicating whether Perl would evaluate the SV as true or false. See "SvOK" for
a defined/undefined test. Handles 'get' magic unless the scalar is already "SvPOK", "SvIOK" or
"SvNOK" (the public, not the private flags).
bool SvTRUE(SV* sv)
sv_true Returns true if the SV has a true value by Perl's rules. Use the "SvTRUE" macro instead, which
may call "sv_true()" or may instead use an in-line version.
I32 sv_true(SV *const sv)
SvTRUE_nomg
Returns a boolean indicating whether Perl would evaluate the SV as true or false. See "SvOK" for
a defined/undefined test. Does not handle 'get' magic.
bool SvTRUE_nomg(SV* sv)
SvTYPE Returns the type of the SV. See "svtype".
svtype SvTYPE(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,
MGVTBL *vtbl)
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)
sv_untaint
Untaint an SV. Use "SvTAINTED_off" instead.
void sv_untaint(SV *const sv)
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
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_flags
Tells an SV to use "ptr" to find its string value. Normally the string is stored inside the SV,
but sv_usepvn allows the SV to use an outside string. "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 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.
If "flags & SV_SMAGIC" is true, will call "SvSETMAGIC". 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").
void sv_usepvn_flags(SV *const sv, char* ptr,
const STRLEN len,
const U32 flags)
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)
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
Attempts 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, either returns false or, if
"fail_ok" is not true, croaks.
This is not a general purpose Unicode to byte encoding interface: use the "Encode" extension for
that.
bool sv_utf8_downgrade(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)
sv_utf8_upgrade
Converts the PV of an SV to its UTF-8-encoded form. Forces the SV to string form if it is not
already. Will "mg_get" on "sv" if appropriate. Always sets the "SvUTF8" flag to avoid future
validity checks even if the whole string is the same in UTF-8 as not. Returns the number of
bytes in the converted string
This is not a general purpose byte encoding to Unicode interface: use the Encode extension for
that.
STRLEN sv_utf8_upgrade(SV *sv)
sv_utf8_upgrade_flags
Converts the PV of an SV to its UTF-8-encoded form. Forces the SV to string form if it is not
already. Always sets the SvUTF8 flag to avoid future validity checks even if all the bytes are
invariant in UTF-8. If "flags" has "SV_GMAGIC" bit set, will "mg_get" on "sv" if appropriate,
else not.
The "SV_FORCE_UTF8_UPGRADE" flag is now ignored.
Returns the number of bytes in the converted string.
This is not a general purpose byte encoding to Unicode interface: use the Encode extension for
that.
STRLEN sv_utf8_upgrade_flags(SV *const sv,
const I32 flags)
sv_utf8_upgrade_flags_grow
Like "sv_utf8_upgrade_flags", but has an additional parameter "extra", which is the number of
unused bytes the string of "sv" is guaranteed to have free after it upon return. This allows the
caller to reserve extra space that it intends to fill, to avoid extra grows.
"sv_utf8_upgrade", "sv_utf8_upgrade_nomg", and "sv_utf8_upgrade_flags" are implemented in terms
of this function.
Returns the number of bytes in the converted string (not including the spares).
STRLEN sv_utf8_upgrade_flags_grow(SV *const sv,
const I32 flags,
STRLEN extra)
sv_utf8_upgrade_nomg
Like "sv_utf8_upgrade", but doesn't do magic on "sv".
STRLEN sv_utf8_upgrade_nomg(SV *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)
SvUV Coerces the given SV to UV and returns 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).
See "SvUVx" for a version which guarantees to evaluate "sv" only once.
UV SvUV(SV* sv)
SvUV_nomg
Like "SvUV" but doesn't process magic.
UV SvUV_nomg(SV* sv)
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)
SvUVx Coerces the given SV to UV and returns 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).
This form guarantees to evaluate "sv" only once. Only use this if "sv" is an expression with
side effects, otherwise use the more efficient "SvUV".
UV SvUVx(SV* sv)
sv_vcatpvf
Processes its arguments like "sv_vcatpvfn" called with a non-null C-style variable argument list,
and appends the formatted output to an SV. Does not handle 'set' magic. See "sv_vcatpvf_mg".
Usually used via its frontend "sv_catpvf".
void sv_vcatpvf(SV *const sv, const char *const pat,
va_list *const args)
sv_vcatpvfn
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)
sv_vcatpvfn_flags
Processes its arguments like "vsprintf" and appends the formatted output to an SV. Uses 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, indicates via "maybe_tainted" if results are
untrustworthy (often due to the use of locales).
If called as "sv_vcatpvfn" or flags has the "SV_GMAGIC" bit set, calls get magic.
It assumes that pat has the same utf8-ness as sv. It's the caller's responsibility to ensure
that this is so.
Usually used via one of its frontends "sv_vcatpvf" and "sv_vcatpvf_mg".
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)
sv_vcatpvf_mg
Like "sv_vcatpvf", but also handles 'set' magic.
Usually used via its frontend "sv_catpvf_mg".
void sv_vcatpvf_mg(SV *const sv,
const char *const pat,
va_list *const args)
SvVOK Returns a boolean indicating whether the SV contains a v-string.
bool SvVOK(SV* sv)
sv_vsetpvf
Works like "sv_vcatpvf" but copies the text into the SV instead of appending it. Does not handle
'set' magic. See "sv_vsetpvf_mg".
Usually used via its frontend "sv_setpvf".
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.
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)
sv_vsetpvf_mg
Like "sv_vsetpvf", but also handles 'set' magic.
Usually used via its frontend "sv_setpvf_mg".
void sv_vsetpvf_mg(SV *const sv,
const char *const pat,
va_list *const args)
Unicode Support
"Unicode Support" in perlguts has an introduction to this API.
See also "Character classification", and "Character case changing". 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: this function 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: this function 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 <http://www.unicode.org/unicode/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)
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)
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.
STRLEN isC9_STRICT_UTF8_CHAR(const U8 *s, const U8 *e)
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)
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_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_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_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_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_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_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 s,
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 s, const U8 * const e,
const U32 flags
)
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.
STRLEN isUTF8_CHAR(const U8 *s, const U8 *e)
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.
STRLEN isUTF8_CHAR_flags(const U8 *s, const U8 *e,
const U32 flags)
pv_uni_display
Build to the scalar "dsv" a displayable version of the 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.
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 cpan/Encode/encoding.pm 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)
to_utf8_fold
DEPRECATED! It is planned to remove this function from a future release of Perl. Do not use it
for new code; remove it from existing code.
Instead use "toFOLD_utf8_safe".
UV to_utf8_fold(const U8 *p, U8* ustrp,
STRLEN *lenp)
to_utf8_lower
DEPRECATED! It is planned to remove this function from a future release of Perl. Do not use it
for new code; remove it from existing code.
Instead use "toLOWER_utf8_safe".
UV to_utf8_lower(const U8 *p, U8* ustrp,
STRLEN *lenp)
to_utf8_title
DEPRECATED! It is planned to remove this function from a future release of Perl. Do not use it
for new code; remove it from existing code.
Instead use "toTITLE_utf8_safe".
UV to_utf8_title(const U8 *p, U8* ustrp,
STRLEN *lenp)
to_utf8_upper
DEPRECATED! It is planned to remove this function from a future release of Perl. Do not use it
for new code; remove it from existing code.
Instead use "toUPPER_utf8_safe".
UV to_utf8_upper(const U8 *p, U8* ustrp,
STRLEN *lenp)
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
<http://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 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
NOTE: this function is experimental and may change or be removed without notice.
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 lexcial 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)
utf8n_to_uvuni
Instead use "utf8_to_uvchr_buf", or rarely, "utf8n_to_uvchr".
This function was useful for code that wanted to handle both EBCDIC and ASCII platforms with
Unicode properties, but starting in Perl v5.20, the distinctions between the platforms have
mostly been made invisible to most code, so this function is quite unlikely to be what you want.
If you do need this precise functionality, use instead "NATIVE_TO_UNI(utf8_to_uvchr_buf(...))"
or "NATIVE_TO_UNI(utf8n_to_uvchr(...))".
UV utf8n_to_uvuni(const U8 *s, STRLEN curlen,
STRLEN *retlen, U32 flags)
UTF8SKIP
returns the number of bytes in the UTF-8 encoded character whose first (perhaps only) byte is
pointed to by "s".
STRLEN UTF8SKIP(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 or backward.
WARNING: do not use the following 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 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.
"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.
"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.
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_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 value gives 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 to have code points that are larger than what can fit in an IV on the
current machine.
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* s, const U8 *e)
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)
utf8_to_bytes
NOTE: this function 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 this function 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)
utf8_to_uvuni_buf
DEPRECATED! It is planned to remove this function from a future release of Perl. Do not use it
for new code; remove it from existing code.
Only in very rare circumstances should code need to be dealing in Unicode (as opposed to native)
code points. In those few cases, use "NATIVE_TO_UNI(utf8_to_uvchr_buf(...))" instead. If you
are not absolutely sure this is one of those cases, then assume it isn't and use plain
"utf8_to_uvchr_buf" instead.
Returns the Unicode (not-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_uvuni_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
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)
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
<http://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
NOTE: this function is experimental and may change or be removed without notice.
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)
uvoffuni_to_utf8_flags
THIS FUNCTION SHOULD BE USED IN ONLY VERY SPECIALIZED CIRCUMSTANCES. Instead, Almost all code
should use "uvchr_to_utf8" or "uvchr_to_utf8_flags".
This function is like them, but the input is a strict Unicode (as opposed to native) code point.
Only in very rare circumstances should code not be using the native code point.
For details, see the description for "uvchr_to_utf8_flags".
U8* uvoffuni_to_utf8_flags(U8 *d, UV uv,
const UV flags)
uvuni_to_utf8_flags
Instead you almost certainly want to use "uvchr_to_utf8" or "uvchr_to_utf8_flags".
This function is a deprecated synonym for "uvoffuni_to_utf8_flags", which itself, while not
deprecated, should be used only in isolated circumstances. These functions were useful for code
that wanted to handle both EBCDIC and ASCII platforms with Unicode properties, but starting in
Perl v5.20, the distinctions between the platforms have mostly been made invisible to most code,
so this function is quite unlikely to be what you want.
U8* uvuni_to_utf8_flags(U8 *d, UV uv, UV flags)
valid_utf8_to_uvchr
Like "utf8_to_uvchr_buf", but should only be called when it is known that the next character in
the input UTF-8 string "s" is well-formed (e.g., it passes "isUTF8_CHAR". Surrogates, non-
character code points, and non-Unicode code points are allowed.
UV valid_utf8_to_uvchr(const U8 *s, STRLEN *retlen)
Variables created by "xsubpp" and "xsubpp" internal functions
newXSproto
Used by "xsubpp" to hook up XSUBs as Perl subs. Adds Perl prototypes to the subs.
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;
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;
Warning and Dieing
ckWARN Returns a boolean as to whether or not warnings are enabled for the warning category "w". If the
category is by default enabled even if not within the scope of "use warnings", instead use the
"ckWARN_d" macro.
bool ckWARN(U32 w)
ckWARN2 Like "ckWARN", but takes two warnings categories as input, and returns TRUE if either is enabled.
If either category is by default enabled even if not within the scope of "use warnings", instead
use the "ckWARN2_d" macro. The categories must be completely independent, one may not be
subclassed from the other.
bool ckWARN2(U32 w1, U32 w2)
ckWARN3 Like "ckWARN2", but takes three warnings categories as input, and returns TRUE if any is enabled.
If any of the categories is by default enabled even if not within the scope of "use warnings",
instead use the "ckWARN3_d" macro. The categories must be completely independent, one may not be
subclassed from any other.
bool ckWARN3(U32 w1, U32 w2, U32 w3)
ckWARN4 Like "ckWARN3", but takes four warnings categories as input, and returns TRUE if any is enabled.
If any of the categories is by default enabled even if not within the scope of "use warnings",
instead use the "ckWARN4_d" macro. The categories must be completely independent, one may not be
subclassed from any other.
bool ckWARN4(U32 w1, U32 w2, U32 w3, U32 w4)
ckWARN_d
Like "ckWARN", but for use if and only if the warning category is by default enabled even if not
within the scope of "use warnings".
bool ckWARN_d(U32 w)
ckWARN2_d
Like "ckWARN2", but for use if and only if either warning category is by default enabled even if
not within the scope of "use warnings".
bool ckWARN2_d(U32 w1, U32 w2)
ckWARN3_d
Like "ckWARN3", but for use if and only if any of the warning categories is by default enabled
even if not within the scope of "use warnings".
bool ckWARN3_d(U32 w1, U32 w2, U32 w3)
ckWARN4_d
Like "ckWARN4", but for use if and only if any of the warning categories is by default enabled
even if not within the scope of "use warnings".
bool ckWARN4_d(U32 w1, U32 w2, U32 w3, U32 w4)
croak This is an XS interface to Perl's "die" function.
Take a sprintf-style format pattern and 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 croak(const char *pat, ...)
croak_no_modify
Exactly equivalent to "Perl_croak(aTHX_ "%s", PL_no_modify)", but generates terser object code
than using "Perl_croak". 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 Behaves the same as "croak", except for the return type. It should be used only where the "OP *"
return type is required. The function never actually returns.
OP * die(const char *pat, ...)
die_sv 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)
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)
vwarn This is an XS interface to Perl's "warn" 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 or object will by default be written to standard error, but this is subject to
modification by a $SIG{__WARN__} handler.
Unlike with "vcroak", "pat" is not permitted to be null.
void vwarn(const char *pat, va_list *args)
warn This is an XS interface to Perl's "warn" function.
Take a sprintf-style format pattern and 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 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.
void warn(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)
Undocumented functions
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.
GetVars
Gv_AMupdate
PerlIO_clearerr
PerlIO_close
PerlIO_context_layers
PerlIO_eof
PerlIO_error
PerlIO_fileno
PerlIO_fill
PerlIO_flush
PerlIO_get_base
PerlIO_get_bufsiz
PerlIO_get_cnt
PerlIO_get_ptr
PerlIO_read
PerlIO_seek
PerlIO_set_cnt
PerlIO_set_ptrcnt
PerlIO_setlinebuf
PerlIO_stderr
PerlIO_stdin
PerlIO_stdout
PerlIO_tell
PerlIO_unread
PerlIO_write
_variant_byte_number
amagic_call
amagic_deref_call
any_dup
atfork_lock
atfork_unlock
av_arylen_p
av_iter_p
block_gimme
call_atexit
call_list
calloc
cast_i32
cast_iv
cast_ulong
cast_uv
ck_warner
ck_warner_d
ckwarn
ckwarn_d
clear_defarray
clone_params_del
clone_params_new
croak_memory_wrap
croak_nocontext
csighandler
cx_dump
cx_dup
cxinc
deb
deb_nocontext
debop
debprofdump
debstack
debstackptrs
delimcpy
despatch_signals
die_nocontext
dirp_dup
do_aspawn
do_binmode
do_close
do_gv_dump
do_gvgv_dump
do_hv_dump
do_join
do_magic_dump
do_op_dump
do_open
do_open9
do_openn
do_pmop_dump
do_spawn
do_spawn_nowait
do_sprintf
do_sv_dump
doing_taint
doref
dounwind
dowantarray
dump_eval
dump_form
dump_indent
dump_mstats
dump_sub
dump_vindent
filter_add
filter_del
filter_read
foldEQ_latin1
form_nocontext
fp_dup
fprintf_nocontext
free_global_struct
free_tmps
get_context
get_mstats
get_op_descs
get_op_names
get_ppaddr
get_vtbl
gp_dup
gp_free
gp_ref
gv_AVadd
gv_HVadd
gv_IOadd
gv_SVadd
gv_add_by_type
gv_autoload4
gv_autoload_pv
gv_autoload_pvn
gv_autoload_sv
gv_check
gv_dump
gv_efullname
gv_efullname3
gv_efullname4
gv_fetchfile
gv_fetchfile_flags
gv_fetchpv
gv_fetchpvn_flags
gv_fetchsv
gv_fullname
gv_fullname3
gv_fullname4
gv_handler
gv_name_set
he_dup
hek_dup
hv_common
hv_common_key_len
hv_delayfree_ent
hv_eiter_p
hv_eiter_set
hv_free_ent
hv_ksplit
hv_name_set
hv_placeholders_get
hv_placeholders_set
hv_rand_set
hv_riter_p
hv_riter_set
ibcmp_utf8
init_global_struct
init_stacks
init_tm
instr
is_lvalue_sub
leave_scope
load_module_nocontext
magic_dump
malloc
markstack_grow
mess_nocontext
mfree
mg_dup
mg_size
mini_mktime
moreswitches
mro_get_from_name
mro_get_private_data
mro_set_mro
mro_set_private_data
my_atof
my_atof2
my_atof3
my_chsize
my_cxt_index
my_cxt_init
my_dirfd
my_exit
my_failure_exit
my_fflush_all
my_fork
my_lstat
my_pclose
my_popen
my_popen_list
my_setenv
my_socketpair
my_stat
my_strftime
newANONATTRSUB
newANONHASH
newANONLIST
newANONSUB
newATTRSUB
newAVREF
newCVREF
newFORM
newGVREF
newGVgen
newGVgen_flags
newHVREF
newHVhv
newIO
newMYSUB
newPROG
newRV
newSUB
newSVREF
newSVpvf_nocontext
newSVsv_flags
new_stackinfo
op_refcnt_lock
op_refcnt_unlock
parser_dup
perl_alloc_using
perl_clone_using
pmop_dump
pop_scope
pregcomp
pregexec
pregfree
pregfree2
printf_nocontext
ptr_table_fetch
ptr_table_free
ptr_table_new
ptr_table_split
ptr_table_store
push_scope
re_compile
re_dup_guts
re_intuit_start
re_intuit_string
realloc
reentrant_free
reentrant_init
reentrant_retry
reentrant_size
ref
reg_named_buff_all
reg_named_buff_exists
reg_named_buff_fetch
reg_named_buff_firstkey
reg_named_buff_nextkey
reg_named_buff_scalar
regdump
regdupe_internal
regexec_flags
regfree_internal
reginitcolors
regnext
repeatcpy
rsignal
rsignal_state
runops_debug
runops_standard
rvpv_dup
safesyscalloc
safesysfree
safesysmalloc
safesysrealloc
save_I16
save_I32
save_I8
save_adelete
save_aelem
save_aelem_flags
save_alloc
save_aptr
save_ary
save_bool
save_clearsv
save_delete
save_destructor
save_destructor_x
save_freeop
save_freepv
save_freesv
save_generic_pvref
save_generic_svref
save_hash
save_hdelete
save_helem
save_helem_flags
save_hints
save_hptr
save_int
save_item
save_iv
save_list
save_long
save_mortalizesv
save_nogv
save_op
save_padsv_and_mortalize
save_pptr
save_pushi32ptr
save_pushptr
save_pushptrptr
save_re_context
save_scalar
save_set_svflags
save_shared_pvref
save_sptr
save_svref
save_vptr
savestack_grow
savestack_grow_cnt
scan_num
scan_vstring
seed
set_context
share_hek
si_dup
ss_dup
stack_grow
start_subparse
str_to_version
sv_2iv
sv_2pv
sv_2uv
sv_catpvf_mg_nocontext
sv_catpvf_nocontext
sv_dup
sv_dup_inc
sv_peek
sv_pvn_nomg
sv_setpvf_mg_nocontext
sv_setpvf_nocontext
sys_init
sys_init3
sys_intern_clear
sys_intern_dup
sys_intern_init
sys_term
taint_env
taint_proper
unlnk
unsharepvn
uvuni_to_utf8
vdeb
vform
vload_module
vnewSVpvf
vwarner
warn_nocontext
warner
warner_nocontext
whichsig
whichsig_pv
whichsig_pvn
whichsig_sv
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
perlguts, perlxs, perlxstut, perlintern
perl v5.30.0 2023-11-23 PERLAPI(1)