Provided by: perl-doc_5.40.0-8_all 
NAME
perldiag - various Perl diagnostics
DESCRIPTION
These messages are classified as follows (listed in increasing order of desperation):
(W) A warning (optional).
(D) A deprecation (enabled by default).
(S) A severe warning (enabled by default).
(F) A fatal error (trappable).
(P) An internal error you should never see (trappable).
(X) A very fatal error (nontrappable).
(A) An alien error message (not generated by Perl).
The majority of messages from the first three classifications above (W, D & S) can be
controlled using the "warnings" pragma.
If a message can be controlled by the "warnings" pragma, its warning category is included
with the classification letter in the description below. E.g. "(W closed)" means a
warning in the "closed" category.
Optional warnings are enabled by using the "warnings" pragma or the -w and -W switches.
Warnings may be captured by setting $SIG{__WARN__} to a reference to a routine that will
be called on each warning instead of printing it. See perlvar.
Severe warnings are always enabled, unless they are explicitly disabled with the
"warnings" pragma or the -X switch.
Trappable errors may be trapped using the eval operator. See "eval" in perlfunc. In
almost all cases, warnings may be selectively disabled or promoted to fatal errors using
the "warnings" pragma. See warnings.
The messages are in alphabetical order, without regard to upper or lower-case. Some of
these messages are generic. Spots that vary are denoted with a %s or other printf-style
escape. These escapes are ignored by the alphabetical order, as are all characters other
than letters. To look up your message, just ignore anything that is not a letter.
accept() on closed socket %s
(W closed) You tried to do an accept on a closed socket. Did you forget to check the
return value of your socket() call? See "accept" in perlfunc.
ADJUST is experimental
(S experimental::class) This warning is emitted if you use the "ADJUST" keyword of
"use feature 'class'". This keyword is currently experimental and its behaviour may
change in future releases of Perl.
Aliasing via reference is experimental
(S experimental::refaliasing) This warning is emitted if you use a reference
constructor on the left-hand side of an assignment to alias one variable to another.
Simply suppress the warning if you want to use the feature, but know that in doing so
you are taking the risk of using an experimental feature which may change or be
removed in a future Perl version:
no warnings "experimental::refaliasing";
use feature "refaliasing";
\$x = \$y;
'%c' allowed only after types %s in %s
(F) The modifiers '!', '<' and '>' are allowed in pack() or unpack() only after
certain types. See "pack" in perlfunc.
alpha->numify() is lossy
(W numeric) An alpha version can not be numified without losing information.
Ambiguous call resolved as CORE::%s(), qualify as such or use &
(W ambiguous) A subroutine you have declared has the same name as a Perl keyword, and
you have used the name without qualification for calling one or the other. Perl
decided to call the builtin because the subroutine is not imported.
To force interpretation as a subroutine call, either put an ampersand before the
subroutine name, or qualify the name with its package. Alternatively, you can import
the subroutine (or pretend that it's imported with the "use subs" pragma).
To silently interpret it as the Perl operator, use the "CORE::" prefix on the operator
(e.g. CORE::log($x)) or declare the subroutine to be an object method (see "Subroutine
Attributes" in perlsub or attributes).
Ambiguous range in transliteration operator
(F) You wrote something like "tr/a-z-0//" which doesn't mean anything at all. To
include a "-" character in a transliteration, put it either first or last. (In the
past, "tr/a-z-0//" was synonymous with "tr/a-y//", which was probably not what you
would have expected.)
Ambiguous use of %s resolved as %s
(S ambiguous) You said something that may not be interpreted the way you thought.
Normally it's pretty easy to disambiguate it by supplying a missing quote, operator,
parenthesis pair or declaration.
Ambiguous use of -%s resolved as -&%s()
(S ambiguous) You wrote something like "-foo", which might be the string "-foo", or a
call to the function "foo", negated. If you meant the string, just write "-foo". If
you meant the function call, write "-foo()".
Ambiguous use of %c resolved as operator %c
(S ambiguous) "%", "&", and "*" are both infix operators (modulus, bitwise and, and
multiplication) and initial special characters (denoting hashes, subroutines and
typeglobs), and you said something like "*foo * foo" that might be interpreted as
either of them. We assumed you meant the infix operator, but please try to make it
more clear -- in the example given, you might write "*foo * foo()" if you really meant
to multiply a glob by the result of calling a function.
Ambiguous use of %c{%s} resolved to %c%s
(W ambiguous) You wrote something like "@{foo}", which might be asking for the
variable @foo, or it might be calling a function named foo, and dereferencing it as an
array reference. If you wanted the variable, you can just write @foo. If you wanted
to call the function, write "@{foo()}" ... or you could just not have a variable and a
function with the same name, and save yourself a lot of trouble.
Ambiguous use of %c{%s[...]} resolved to %c%s[...]
Ambiguous use of %c{%s{...}} resolved to %c%s{...}
(W ambiguous) You wrote something like "${foo[2]}" (where foo represents the name of a
Perl keyword), which might be looking for element number 2 of the array named @foo, in
which case please write $foo[2], or you might have meant to pass an anonymous arrayref
to the function named foo, and then do a scalar deref on the value it returns. If you
meant that, write "${foo([2])}".
In regular expressions, the "${foo[2]}" syntax is sometimes necessary to disambiguate
between array subscripts and character classes. "/$length[2345]/", for instance, will
be interpreted as $length followed by the character class "[2345]". If an array
subscript is what you want, you can avoid the warning by changing "/${length[2345]}/"
to the unsightly "/${\$length[2345]}/", by renaming your array to something that does
not coincide with a built-in keyword, or by simply turning off warnings with "no
warnings 'ambiguous';".
'|' and '<' may not both be specified on command line
(F) An error peculiar to VMS. Perl does its own command line redirection, and found
that STDIN was a pipe, and that you also tried to redirect STDIN using '<'. Only one
STDIN stream to a customer, please.
'|' and '>' may not both be specified on command line
(F) An error peculiar to VMS. Perl does its own command line redirection, and thinks
you tried to redirect stdout both to a file and into a pipe to another command. You
need to choose one or the other, though nothing's stopping you from piping into a
program or Perl script which 'splits' output into two streams, such as
open(OUT,">$ARGV[0]") or die "Can't write to $ARGV[0]: $!";
while (<STDIN>) {
print;
print OUT;
}
close OUT;
Applying %s to %s will act on scalar(%s)
(W misc) The pattern match ("//"), substitution ("s///"), and transliteration
("tr///") operators work on scalar values. If you apply one of them to an array or a
hash, it will convert the array or hash to a scalar value (the length of an array, or
the population info of a hash) and then work on that scalar value. This is probably
not what you meant to do. See "grep" in perlfunc and "map" in perlfunc for
alternatives.
Arg too short for msgsnd
(F) msgsnd() requires a string at least as long as sizeof(long).
Argument "%s" isn't numeric%s
(W numeric) The indicated string was fed as an argument to an operator that expected a
numeric value instead. If you're fortunate the message will identify which operator
was so unfortunate.
Note that for the "Inf" and "NaN" (infinity and not-a-number) the definition of
"numeric" is somewhat unusual: the strings themselves (like "Inf") are considered
numeric, and anything following them is considered non-numeric.
Argument list not closed for PerlIO layer "%s"
(W layer) When pushing a layer with arguments onto the Perl I/O system you forgot the
) that closes the argument list. (Layers take care of transforming data between
external and internal representations.) Perl stopped parsing the layer list at this
point and did not attempt to push this layer. If your program didn't explicitly
request the failing operation, it may be the result of the value of the environment
variable PERLIO.
Argument "%s" treated as 0 in increment (++)
(W numeric) The indicated string was fed as an argument to the "++" operator which
expects either a number or a string matching "/^[a-zA-Z]*[0-9]*\z/". See "Auto-
increment and Auto-decrement" in perlop for details.
Array passed to stat will be coerced to a scalar%s
(W syntax) You called stat() on an array, but the array will be coerced to a scalar -
the number of elements in the array.
A signature parameter must start with '$', '@' or '%'
(F) Each subroutine signature parameter declaration must start with a valid sigil; for
example:
sub foo ($x, $, $y = 1, @z) {}
A slurpy parameter may not have a default value
(F) Only scalar subroutine signature parameters may have a default value; for example:
sub foo ($x = 1) {} # legal
sub foo (@x = (1)) {} # invalid
sub foo (%x = (a => b)) {} # invalid
assertion botched: %s
(X) The malloc package that comes with Perl had an internal failure.
Assertion %s failed: file "%s", line %d
(X) A general assertion failed. The file in question must be examined.
Assigned value is not a reference
(F) You tried to assign something that was not a reference to an lvalue reference
(e.g., "\$x = $y"). If you meant to make $x an alias to $y, use "\$x = \$y".
Assigned value is not %s reference
(F) You tried to assign a reference to a reference constructor, but the two references
were not of the same type. You cannot alias a scalar to an array, or an array to a
hash; the two types must match.
\$x = \@y; # error
\@x = \%y; # error
$y = [];
\$x = $y; # error; did you mean \$y?
Assigning non-zero to $[ is no longer possible
(F) When the "array_base" feature is disabled (e.g., and under "use v5.16;", and as of
Perl 5.30) the special variable $[, which is deprecated, is now a fixed zero value.
Assignment to both a list and a scalar
(F) If you assign to a conditional operator, the 2nd and 3rd arguments must either
both be scalars or both be lists. Otherwise Perl won't know which context to supply
to the right side.
Assuming NOT a POSIX class since %s in regex; marked by <-- HERE in m/%s/
(W regexp) You had something like these:
[[:alnum]]
[[:digit:xyz]
They look like they might have been meant to be the POSIX classes "[:alnum:]" or
"[:digit:]". If so, they should be written:
[[:alnum:]]
[[:digit:]xyz]
Since these aren't legal POSIX class specifications, but are legal bracketed character
classes, Perl treats them as the latter. In the first example, it matches the
characters ":", "[", "a", "l", "m", "n", and "u".
If these weren't meant to be POSIX classes, this warning message is spurious, and can
be suppressed by reordering things, such as
[[al:num]]
or
[[:munla]]
<> at require-statement should be quotes
(F) You wrote "require <file>" when you should have written "require 'file'".
Attempt to access disallowed key '%s' in a restricted hash
(F) The failing code has attempted to get or set a key which is not in the current set
of allowed keys of a restricted hash.
Attempt to bless into a freed package
(F) You wrote "bless $foo" with one argument after somehow causing the current package
to be freed. Perl cannot figure out what to do, so it throws up its hands in despair.
Attempt to bless into a class
(F) You are attempting to call "bless" with a package name that is a new-style
"class". This is not necessary, as instances created by the constructor are already
in the correct class. Instances cannot be created by other means, such as "bless".
Attempt to bless into a reference
(F) The CLASSNAME argument to the bless() operator is expected to be the name of the
package to bless the resulting object into. You've supplied instead a reference to
something: perhaps you wrote
bless $self, $proto;
when you intended
bless $self, ref($proto) || $proto;
If you actually want to bless into the stringified version of the reference supplied,
you need to stringify it yourself, for example by:
bless $self, "$proto";
Attempt to clear deleted array
(S debugging) An array was assigned to when it was being freed. Freed values are not
supposed to be visible to Perl code. This can also happen if XS code calls "av_clear"
from a custom magic callback on the array.
Attempt to delete disallowed key '%s' from a restricted hash
(F) The failing code attempted to delete from a restricted hash a key which is not in
its key set.
Attempt to delete readonly key '%s' from a restricted hash
(F) The failing code attempted to delete a key whose value has been declared readonly
from a restricted hash.
Attempt to free non-arena SV: 0x%x
(S internal) All SV objects are supposed to be allocated from arenas that will be
garbage collected on exit. An SV was discovered to be outside any of those arenas.
Attempt to free nonexistent shared string '%s'%s
(S internal) Perl maintains a reference-counted internal table of strings to optimize
the storage and access of hash keys and other strings. This indicates someone tried
to decrement the reference count of a string that can no longer be found in the table.
Attempt to free temp prematurely: SV 0x%x
(S debugging) Mortalized values are supposed to be freed by the free_tmps() routine.
This indicates that something else is freeing the SV before the free_tmps() routine
gets a chance, which means that the free_tmps() routine will be freeing an
unreferenced scalar when it does try to free it.
Attempt to free unreferenced glob pointers
(S internal) The reference counts got screwed up on symbol aliases.
Attempt to free unreferenced scalar: SV 0x%x
(S internal) Perl went to decrement the reference count of a scalar to see if it would
go to 0, and discovered that it had already gone to 0 earlier, and should have been
freed, and in fact, probably was freed. This could indicate that SvREFCNT_dec() was
called too many times, or that SvREFCNT_inc() was called too few times, or that the SV
was mortalized when it shouldn't have been, or that memory has been corrupted.
Attempt to pack pointer to temporary value
(W pack) You tried to pass a temporary value (like the result of a function, or a
computed expression) to the "p" pack() template. This means the result contains a
pointer to a location that could become invalid anytime, even before the end of the
current statement. Use literals or global values as arguments to the "p" pack()
template to avoid this warning.
Attempt to reload %s aborted.
(F) You tried to load a file with "use" or "require" that failed to compile once
already. Perl will not try to compile this file again unless you delete its entry
from %INC. See "require" in perlfunc and "%INC" in perlvar.
Attempt to set length of freed array
(W misc) You tried to set the length of an array which has been freed. You can do
this by storing a reference to the scalar representing the last index of an array and
later assigning through that reference. For example
$r = do {my @a; \$#a};
$$r = 503
Attempt to use reference as lvalue in substr
(W substr) You supplied a reference as the first argument to substr() used as an
lvalue, which is pretty strange. Perhaps you forgot to dereference it first. See
"substr" in perlfunc.
Attribute prototype(%s) discards earlier prototype attribute in same sub
(W misc) A sub was declared as sub foo : prototype(A) : prototype(B) {}, for example.
Since each sub can only have one prototype, the earlier declaration(s) are discarded
while the last one is applied.
av_reify called on tied array
(S debugging) This indicates that something went wrong and Perl got very confused
about @_ or @DB::args being tied.
Bad arg length for %s, is %u, should be %d
(F) You passed a buffer of the wrong size to one of msgctl(), semctl() or shmctl().
In C parlance, the correct sizes are, respectively, sizeof(struct msqid_ds *),
sizeof(struct semid_ds *), and sizeof(struct shmid_ds *).
Bad evalled substitution pattern
(F) You've used the "/e" switch to evaluate the replacement for a substitution, but
perl found a syntax error in the code to evaluate, most likely an unexpected right
brace '}'.
Bad filehandle: %s
(F) A symbol was passed to something wanting a filehandle, but the symbol has no
filehandle associated with it. Perhaps you didn't do an open(), or did it in another
package.
Bad free() ignored
(S malloc) An internal routine called free() on something that had never been
malloc()ed in the first place. Mandatory, but can be disabled by setting environment
variable "PERL_BADFREE" to 0.
This message can be seen quite often with DB_File on systems with "hard" dynamic
linking, like "AIX" and "OS/2". It is a bug of "Berkeley DB" which is left unnoticed
if "DB" uses forgiving system malloc().
Bad infix plugin result (%zd) - did not consume entire identifier <%s>
(F) A plugin using the "PL_infix_plugin" mechanism to parse an infix keyword consumed
part of a named identifier operator name but did not consume all of it. This is not
permitted as it leads to fragile parsing results.
Badly placed ()'s
(A) You've accidentally run your script through csh instead of Perl. Check the #!
line, or manually feed your script into Perl yourself.
Bad name after %s
(F) You started to name a symbol by using a package prefix, and then didn't finish the
symbol. In particular, you can't interpolate outside of quotes, so
$var = 'myvar';
$sym = mypack::$var;
is not the same as
$var = 'myvar';
$sym = "mypack::$var";
Bad plugin affecting keyword '%s'
(F) An extension using the keyword plugin mechanism violated the plugin API.
Bad realloc() ignored
(S malloc) An internal routine called realloc() on something that had never been
malloc()ed in the first place. Mandatory, but can be disabled by setting the
environment variable "PERL_BADFREE" to 1.
Bad symbol for %s
(P) An internal request asked to add an entry of the named type to something that
wasn't a symbol table entry.
Bad symbol for scalar
(P) An internal request asked to add a scalar entry to something that wasn't a symbol
table entry.
Bareword found in conditional
(W bareword) The compiler found a bareword where it expected a conditional, which
often indicates that an || or && was parsed as part of the last argument of the
previous construct, for example:
open FOO || die;
It may also indicate a misspelled constant that has been interpreted as a bareword:
use constant TYPO => 1;
if (TYOP) { print "foo" }
The "strict" pragma is useful in avoiding such errors.
Bareword in require contains "%s"
Bareword in require maps to disallowed filename "%s"
Bareword in require maps to empty filename
(F) The bareword form of require has been invoked with a filename which could not have
been generated by a valid bareword permitted by the parser. You shouldn't be able to
get this error from Perl code, but XS code may throw it if it passes an invalid module
name to "Perl_load_module".
Bareword in require must not start with a double-colon: "%s"
(F) In "require Bare::Word", the bareword is not allowed to start with a double-colon.
Write "require ::Foo::Bar" as "require Foo::Bar" instead.
Bareword "%s" not allowed while "strict subs" in use
(F) With "strict subs" in use, a bareword is only allowed as a subroutine identifier,
in curly brackets or to the left of the "=>" symbol. Perhaps you need to predeclare a
subroutine?
Bareword "%s" refers to nonexistent package
(W bareword) You used a qualified bareword of the form "Foo::", but the compiler saw
no other uses of that namespace before that point. Perhaps you need to predeclare a
package?
Bareword filehandle "%s" not allowed under 'no feature "bareword_filehandles"'
(F) You attempted to use a bareword filehandle with the "bareword_filehandles" feature
disabled.
Only the built-in handles "STDIN", "STDOUT", "STDERR", "ARGV", "ARGVOUT" and "DATA"
can be used with the "bareword_filehandles" feature disabled.
BEGIN failed--compilation aborted
(F) An untrapped exception was raised while executing a BEGIN subroutine. Compilation
stops immediately and the interpreter is exited.
BEGIN not safe after errors--compilation aborted
(F) Perl found a "BEGIN {}" subroutine (or a "use" directive, which implies a "BEGIN
{}") after one or more compilation errors had already occurred. Since the intended
environment for the "BEGIN {}" could not be guaranteed (due to the errors), and since
subsequent code likely depends on its correct operation, Perl just gave up.
\%d better written as $%d
(W syntax) Outside of patterns, backreferences live on as variables. The use of
backslashes is grandfathered on the right-hand side of a substitution, but
stylistically it's better to use the variable form because other Perl programmers will
expect it, and it works better if there are more than 9 backreferences.
Binary number > 0b11111111111111111111111111111111 non-portable
(W portable) The binary number you specified is larger than 2**32-1 (4294967295) and
therefore non-portable between systems. See perlport for more on portability
concerns.
bind() on closed socket %s
(W closed) You tried to do a bind on a closed socket. Did you forget to check the
return value of your socket() call? See "bind" in perlfunc.
binmode() on closed filehandle %s
(W unopened) You tried binmode() on a filehandle that was never opened. Check your
control flow and number of arguments.
Bit vector size > 32 non-portable
(W portable) Using bit vector sizes larger than 32 is non-portable.
Bizarre copy of %s
(P) Perl detected an attempt to copy an internal value that is not copiable.
Bizarre SvTYPE [%d]
(P) When starting a new thread or returning values from a thread, Perl encountered an
invalid data type.
Both or neither range ends should be Unicode in regex; marked by <-- HERE in m/%s/
(W regexp) (only under "use re 'strict'" or within "(?[...])")
In a bracketed character class in a regular expression pattern, you had a range which
has exactly one end of it specified using "\N{}", and the other end is specified using
a non-portable mechanism. Perl treats the range as a Unicode range, that is, all the
characters in it are considered to be the Unicode characters, and which may be
different code points on some platforms Perl runs on. For example, "[\N{U+06}-\x08]"
is treated as if you had instead said "[\N{U+06}-\N{U+08}]", that is it matches the
characters whose code points in Unicode are 6, 7, and 8. But that "\x08" might
indicate that you meant something different, so the warning gets raised.
Buffer overflow in prime_env_iter: %s
(W internal) A warning peculiar to VMS. While Perl was preparing to iterate over
%ENV, it encountered a logical name or symbol definition which was too long, so it was
truncated to the string shown.
Built-in function '%s' is experimental
(S experimental::builtin) A call is being made to a function in the "builtin::"
namespace, which is currently experimental. The existence or nature of the function
may be subject to change in a future version of Perl.
builtin::import can only be called at compile time
(F) The "import" method of the "builtin" package was invoked when no code is currently
being compiled. Since this method is used to introduce new lexical subroutines into
the scope currently being compiled, this is not going to have any effect.
Builtin version bundle "%s" is not supported by Perl
(F) You attempted to "use builtin :ver" for a version number that is either older than
5.39 (when the ability was added), or newer than the current perl version.
Callback called exit
(F) A subroutine invoked from an external package via call_sv() exited by calling
exit.
%s() called too early to check prototype
(W prototype) You've called a function that has a prototype before the parser saw a
definition or declaration for it, and Perl could not check that the call conforms to
the prototype. You need to either add an early prototype declaration for the
subroutine in question, or move the subroutine definition ahead of the call to get
proper prototype checking. Alternatively, if you are certain that you're calling the
function correctly, you may put an ampersand before the name to avoid the warning.
See perlsub.
Cannot assign :param(%s) to field %s because that name is already in use
(F) An attempt was made to apply a parameter name to a field, when the name is already
being used by another field in the same class, or one of its parent classes. This
would cause a name clash so is not allowed.
Cannot chr %f
(F) You passed an invalid number (like an infinity or not-a-number) to "chr".
Cannot complete in-place edit of %s: %s
(F) Your perl script appears to have changed directory while performing an in-place
edit of a file specified by a relative path, and your system doesn't include the
directory relative POSIX functions needed to handle that.
Cannot compress %f in pack
(F) You tried compressing an infinity or not-a-number as an unsigned integer with BER,
which makes no sense.
Cannot compress integer in pack
(F) An argument to pack("w",...) was too large to compress. The BER compressed
integer format can only be used with positive integers, and you attempted to compress
a very large number (> 1e308). See "pack" in perlfunc.
Cannot compress negative numbers in pack
(F) An argument to pack("w",...) was negative. The BER compressed integer format can
only be used with positive integers. See "pack" in perlfunc.
Cannot convert a reference to %s to typeglob
(F) You manipulated Perl's symbol table directly, stored a reference in it, then tried
to access that symbol via conventional Perl syntax. The access triggers Perl to
autovivify that typeglob, but it there is no legal conversion from that type of
reference to a typeglob.
Cannot copy to %s
(P) Perl detected an attempt to copy a value to an internal type that cannot be
directly assigned to.
Cannot create class %s as it already has a non-empty @ISA
(F) An attempt was made to create a class out of a package that already has an @ISA
array, and the array is not empty. This is not permitted, as it would lead to a class
with inconsistent inheritance.
Cannot create an object of incomplete class "%s"
(F) An attempt was made to create an object of a class where the start of the class
definition has been seen, but the class has not been completed.
This can happen for a failed eval, or if you attempt to create an object at compile
time before the class is complete:
eval "class Foo {"; Foo->new; # error
class Bar { BEGIN { Bar->new } }; # error
Cannot find encoding "%s"
(S io) You tried to apply an encoding that did not exist to a filehandle, either with
open() or binmode().
Cannot invoke a method of "%s" on an instance of "%s"
(F) You tried to directly call a "method" subroutine of one class by passing in a
value that is an instance of a different class. This is not permitted, as the method
would not have access to the correct instance fields.
Cannot invoke method on a non-instance
(F) You tried to directly call a "method" subroutine of a class by passing in a value
that is not an instance of that class. This is not permitted, as the method would not
then have access to its instance fields.
Cannot open %s as a dirhandle: it is already open as a filehandle
(F) You tried to use opendir() to associate a dirhandle to a symbol (glob or scalar)
that already holds a filehandle. Since this idiom might render your code confusing,
it was deprecated in Perl 5.10. As of Perl 5.28, it is a fatal error.
Cannot open %s as a filehandle: it is already open as a dirhandle
(F) You tried to use open() to associate a filehandle to a symbol (glob or scalar)
that already holds a dirhandle. Since this idiom might render your code confusing, it
was deprecated in Perl 5.10. As of Perl 5.28, it is a fatal error.
Cannot '%s' outside of a 'class'
(F) You attempted to use one of the keywords that only makes sense inside a "class"
definition, at a location that is not inside such a class.
Cannot pack %f with '%c'
(F) You tried converting an infinity or not-a-number to an integer, which makes no
sense.
Cannot printf %f with '%c'
(F) You tried printing an infinity or not-a-number as a character (%c), which makes no
sense. Maybe you meant '%s', or just stringifying it?
Cannot reopen existing class "%s"
(F) You tried to begin a "class" definition for a class that already exists. A class
may only have one definition block.
Cannot set tied @DB::args
(F) "caller" tried to set @DB::args, but found it tied. Tying @DB::args is not
supported. (Before this error was added, it used to crash.)
Cannot tie unreifiable array
(P) You somehow managed to call "tie" on an array that does not keep a reference count
on its arguments and cannot be made to do so. Such arrays are not even supposed to be
accessible to Perl code, but are only used internally.
Cannot use __CLASS__ outside of a method or field initializer expression
(F) A "__CLASS__" expression yields the class name of the object instance executing
the current method, and therefore it can only be placed inside an actual method (or
method-like expression, such as a field initializer expression).
Cannot yet reorder sv_vcatpvfn() arguments from va_list
(F) Some XS code tried to use sv_vcatpvfn() or a related function with a format string
that specifies explicit indexes for some of the elements, and using a C-style
variable-argument list (a "va_list"). This is not currently supported. XS authors
wanting to do this must instead construct a C array of "SV*" scalars containing the
arguments.
Can only compress unsigned integers in pack
(F) An argument to pack("w",...) was not an integer. The BER compressed integer
format can only be used with positive integers, and you attempted to compress
something else. See "pack" in perlfunc.
Can't "%s" out of a "defer" block
(F) An attempt was made to jump out of the scope of a "defer" block by using a
control-flow statement such as "return", "goto" or a loop control. This is not
permitted.
Can't "%s" out of a "finally" block
(F) Similar to above, but involving a "finally" block at the end of a "try"/"catch"
construction rather than a "defer" block.
Can't bless an object reference
(F) You attempted to call "bless" on a value that already refers to a real object
instance.
Can't bless non-reference value
(F) Only hard references may be blessed. This is how Perl "enforces" encapsulation of
objects. See perlobj.
Can't "break" in a loop topicalizer
(F) You called "break", but you're in a "foreach" block rather than a "given" block.
You probably meant to use "next" or "last".
Can't "break" outside a given block
(F) You called "break", but you're not inside a "given" block.
Can't call destructor for 0x%p in global destruction
(S) This should not happen. Internals code has set up a destructor using
"mortal_destructor_sv" or "mortal_destructor_x" which is firing during global
destruction. Please attempt to reduce the code that triggers this warning down to a
small an example as possible and then report the problem to
<https://github.com/Perl/perl5/issues/new/choose>
Can't call method "%s" on an undefined value
(F) You used the syntax of a method call, but the slot filled by the object reference
or package name contains an undefined value. Something like this will reproduce the
error:
$BADREF = undef;
process $BADREF 1,2,3;
$BADREF->process(1,2,3);
Can't call method "%s" on unblessed reference
(F) A method call must know in what package it's supposed to run. It ordinarily finds
this out from the object reference you supply, but you didn't supply an object
reference in this case. A reference isn't an object reference until it has been
blessed. See perlobj.
Can't call method "%s" without a package or object reference
(F) You used the syntax of a method call, but the slot filled by the object reference
or package name contains an expression that returns a defined value which is neither
an object reference nor a package name. Something like this will reproduce the error:
$BADREF = 42;
process $BADREF 1,2,3;
$BADREF->process(1,2,3);
Can't call mro_isa_changed_in() on anonymous symbol table
(P) Perl got confused as to whether a hash was a plain hash or a symbol table hash
when trying to update @ISA caches.
Can't call mro_method_changed_in() on anonymous symbol table
(F) An XS module tried to call "mro_method_changed_in" on a hash that was not attached
to the symbol table.
Can't chdir to %s
(F) You called "perl -x/foo/bar", but /foo/bar is not a directory that you can chdir
to, possibly because it doesn't exist.
Can't coerce %s to %s in %s
(F) Certain types of SVs, in particular real symbol table entries (typeglobs), can't
be forced to stop being what they are. So you can't say things like:
*foo += 1;
You CAN say
$foo = *foo;
$foo += 1;
but then $foo no longer contains a glob.
Can't "continue" outside a when block
(F) You called "continue", but you're not inside a "when" or "default" block.
can't convert empty path
(F) On Cygwin, you called a path conversion function with an empty path. Only non-
empty paths are legal.
Can't create pipe mailbox
(P) An error peculiar to VMS. The process is suffering from exhausted quotas or other
plumbing problems.
Can't declare %s in "%s"
(F) Only scalar, array, and hash variables may be declared as "my", "our" or "state"
variables. They must have ordinary identifiers as names.
Can't "default" outside a topicalizer
(F) You have used a "default" block that is neither inside a "foreach" loop nor a
"given" block. (Note that this error is issued on exit from the "default" block, so
you won't get the error if you use an explicit "continue".)
Can't determine class of operator %s, assuming BASEOP
(S) This warning indicates something wrong in the internals of perl. Perl was trying
to find the class (e.g. LISTOP) of a particular OP, and was unable to do so. This is
likely to be due to a bug in the perl internals, or due to a bug in XS code which
manipulates perl optrees.
Can't do inplace edit: %s is not a regular file
(S inplace) You tried to use the -i switch on a special file, such as a file in /dev,
a FIFO or an uneditable directory. The file was ignored.
Can't do inplace edit on %s: %s
(S inplace) The creation of the new file failed for the indicated reason.
Can't do inplace edit: %s would not be unique
(S inplace) Your filesystem does not support filenames longer than 14 characters and
Perl was unable to create a unique filename during inplace editing with the -i switch.
The file was ignored.
Can't do %s("%s") on non-UTF-8 locale; resolved to "%s".
(W locale) You are 1) running under ""use locale""; 2) the current locale is not a
UTF-8 one; 3) you tried to do the designated case-change operation on the specified
Unicode character; and 4) the result of this operation would mix Unicode and locale
rules, which likely conflict. Mixing of different rule types is forbidden, so the
operation was not done; instead the result is the indicated value, which is the best
available that uses entirely Unicode rules. That turns out to almost always be the
original character, unchanged.
It is generally a bad idea to mix non-UTF-8 locales and Unicode, and this issue is one
of the reasons why. This warning is raised when Unicode rules would normally cause
the result of this operation to contain a character that is in the range specified by
the locale, 0..255, and hence is subject to the locale's rules, not Unicode's.
If you are using locale purely for its characteristics related to things like its
numeric and time formatting (and not "LC_CTYPE"), consider using a restricted form of
the locale pragma (see "The "use locale" pragma" in perllocale) like
""use locale ':not_characters'"".
Note that failed case-changing operations done as a result of case-insensitive "/i"
regular expression matching will show up in this warning as having the "fc" operation
(as that is what the regular expression engine calls behind the scenes.)
Can't do waitpid with flags
(F) This machine doesn't have either waitpid() or wait4(), so only waitpid() without
flags is emulated.
Can't emulate -%s on #! line
(F) The #! line specifies a switch that doesn't make sense at this point. For
example, it'd be kind of silly to put a -x on the #! line.
Can't %s %s-endian %ss on this platform
(F) Your platform's byte-order is neither big-endian nor little-endian, or it has a
very strange pointer size. Packing and unpacking big- or little-endian floating point
values and pointers may not be possible. See "pack" in perlfunc.
Can't exec "%s": %s
(W exec) A system(), exec(), or piped open call could not execute the named program
for the indicated reason. Typical reasons include: the permissions were wrong on the
file, the file wasn't found in $ENV{PATH}, the executable in question was compiled for
another architecture, or the #! line in a script points to an interpreter that can't
be run for similar reasons. (Or maybe your system doesn't support #! at all.)
Can't exec %s
(F) Perl was trying to execute the indicated program for you because that's what the
#! line said. If that's not what you wanted, you may need to mention "perl" on the #!
line somewhere.
Can't execute %s
(F) You used the -S switch, but the copies of the script to execute found in the PATH
did not have correct permissions.
Can't find an opnumber for "%s"
(F) A string of a form "CORE::word" was given to prototype(), but there is no builtin
with the name "word".
Can't find label %s
(F) You said to goto a label that isn't mentioned anywhere that it's possible for us
to go to. See "goto" in perlfunc.
Can't find %s on PATH
(F) You used the -S switch, but the script to execute could not be found in the PATH.
Can't find %s on PATH, '.' not in PATH
(F) You used the -S switch, but the script to execute could not be found in the PATH,
or at least not with the correct permissions. The script exists in the current
directory, but PATH prohibits running it.
Can't find string terminator %s anywhere before EOF
(F) Perl strings can stretch over multiple lines. This message means that the closing
delimiter was omitted. Because bracketed quotes count nesting levels, the following
is missing its final parenthesis:
print q(The character '(' starts a side comment.);
If you're getting this error from a here-document, you may have included unseen
whitespace before or after your closing tag or there may not be a linebreak after it.
A good programmer's editor will have a way to help you find these characters (or lack
of characters). See perlop for the full details on here-documents.
Can't find Unicode property definition "%s"
Can't find Unicode property definition "%s" in regex; marked by <-- HERE in m/%s/
(F) The named property which you specified via "\p" or "\P" is not one known to Perl.
Perhaps you misspelled the name? See "Properties accessible through \p{} and \P{}" in
perluniprops for a complete list of available official properties. If it is a user-
defined property it must have been defined by the time the regular expression is
matched.
If you didn't mean to use a Unicode property, escape the "\p", either by "\\p" (just
the "\p") or by "\Q\p" (the rest of the string, or until "\E").
Can't fork: %s
(F) A fatal error occurred while trying to fork while opening a pipeline.
Can't fork, trying again in 5 seconds
(W pipe) A fork in a piped open failed with EAGAIN and will be retried after five
seconds.
Can't get filespec - stale stat buffer?
(S) A warning peculiar to VMS. This arises because of the difference between access
checks under VMS and under the Unix model Perl assumes. Under VMS, access checks are
done by filename, rather than by bits in the stat buffer, so that ACLs and other
protections can be taken into account. Unfortunately, Perl assumes that the stat
buffer contains all the necessary information, and passes it, instead of the filespec,
to the access-checking routine. It will try to retrieve the filespec using the device
name and FID present in the stat buffer, but this works only if you haven't made a
subsequent call to the CRTL stat() routine, because the device name is overwritten
with each call. If this warning appears, the name lookup failed, and the access-
checking routine gave up and returned FALSE, just to be conservative. (Note: The
access-checking routine knows about the Perl "stat" operator and file tests, so you
shouldn't ever see this warning in response to a Perl command; it arises only if some
internal code takes stat buffers lightly.)
Can't get pipe mailbox device name
(P) An error peculiar to VMS. After creating a mailbox to act as a pipe, Perl can't
retrieve its name for later use.
Can't get SYSGEN parameter value for MAXBUF
(P) An error peculiar to VMS. Perl asked $GETSYI how big you want your mailbox
buffers to be, and didn't get an answer.
Can't "goto" into a binary or list expression
(F) A "goto" statement was executed to jump into the middle of a binary or list
expression. You can't get there from here. The reason for this restriction is that
the interpreter would get confused as to how many arguments there are, resulting in
stack corruption or crashes. This error occurs in cases such as these:
goto F;
print do { F: }; # Can't jump into the arguments to print
goto G;
$x + do { G: $y }; # How is + supposed to get its first operand?
Can't "goto" into a "defer" block
(F) A "goto" statement was executed to jump into the scope of a "defer" block. This
is not permitted.
Can't "goto" into a "given" block
(F) A "goto" statement was executed to jump into the middle of a "given" block. You
can't get there from here. See "goto" in perlfunc.
Can't "goto" into the middle of a foreach loop
(F) A "goto" statement was executed to jump into the middle of a foreach loop. You
can't get there from here. See "goto" in perlfunc.
Can't "goto" out of a pseudo block
(F) A "goto" statement was executed to jump out of what might look like a block,
except that it isn't a proper block. This usually occurs if you tried to jump out of
a sort() block or subroutine, which is a no-no. See "goto" in perlfunc.
Can't goto subroutine from an eval-%s
(F) The "goto subroutine" call can't be used to jump out of an eval "string" or block.
Can't goto subroutine from a sort sub (or similar callback)
(F) The "goto subroutine" call can't be used to jump out of the comparison sub for a
sort(), or from a similar callback (such as the reduce() function in List::Util).
Can't goto subroutine outside a subroutine
(F) The deeply magical "goto subroutine" call can only replace one subroutine call for
another. It can't manufacture one out of whole cloth. In general you should be
calling it out of only an AUTOLOAD routine anyway. See "goto" in perlfunc.
Can't ignore signal CHLD, forcing to default
(W signal) Perl has detected that it is being run with the SIGCHLD signal (sometimes
known as SIGCLD) disabled. Since disabling this signal will interfere with proper
determination of exit status of child processes, Perl has reset the signal to its
default value. This situation typically indicates that the parent program under which
Perl may be running (e.g. cron) is being very careless.
Can't kill a non-numeric process ID
(F) Process identifiers must be (signed) integers. It is a fatal error to attempt to
kill() an undefined, empty-string or otherwise non-numeric process identifier.
Can't "last" outside a loop block
(F) A "last" statement was executed to break out of the current block, except that
there's this itty bitty problem called there isn't a current block. Note that an "if"
or "else" block doesn't count as a "loopish" block, as doesn't a block given to
sort(), map() or grep(). You can usually double the curlies to get the same effect
though, because the inner curlies will be considered a block that loops once. See
"last" in perlfunc.
Can't linearize anonymous symbol table
(F) Perl tried to calculate the method resolution order (MRO) of a package, but failed
because the package stash has no name.
Can't load '%s' for module %s
(F) The module you tried to load failed to load a dynamic extension. This may either
mean that you upgraded your version of perl to one that is incompatible with your old
dynamic extensions (which is known to happen between major versions of perl), or (more
likely) that your dynamic extension was built against an older version of the library
that is installed on your system. You may need to rebuild your old dynamic
extensions.
Can't localize lexical variable %s
(F) You used local on a variable name that was previously declared as a lexical
variable using "my" or "state". This is not allowed. If you want to localize a
package variable of the same name, qualify it with the package name.
Can't localize through a reference
(F) You said something like "local $$ref", which Perl can't currently handle, because
when it goes to restore the old value of whatever $ref pointed to after the scope of
the local() is finished, it can't be sure that $ref will still be a reference.
Can't locate %s
(F) You said to "do" (or "require", or "use") a file that couldn't be found. Perl
looks for the file in all the locations mentioned in @INC, unless the file name
included the full path to the file. Perhaps you need to set the PERL5LIB or PERL5OPT
environment variable to say where the extra library is, or maybe the script needs to
add the library name to @INC. Or maybe you just misspelled the name of the file. See
"require" in perlfunc and lib.
Can't locate auto/%s.al in @INC
(F) A function (or method) was called in a package which allows autoload, but there is
no function to autoload. Most probable causes are a misprint in a function/method
name or a failure to "AutoSplit" the file, say, by doing "make install".
Can't locate loadable object for module %s in @INC
(F) The module you loaded is trying to load an external library, like for example,
foo.so or bar.dll, but the DynaLoader module was unable to locate this library. See
DynaLoader.
Can't locate object method "%s" via package "%s"
(F) You called a method correctly, and it correctly indicated a package functioning as
a class, but that package doesn't define that particular method, nor does any of its
base classes. See perlobj.
Can't locate object method "%s" via package "%s" (perhaps you forgot to load "%s"?)
(F) You called a method on a class that did not exist, and the method could not be
found in UNIVERSAL. This often means that a method requires a package that has not
been loaded.
Can't locate object method "INC", nor "INCDIR" nor string overload via package "%s" %s in
@INC
(F) You pushed an object, either directly or via an array reference hook, into @INC,
but the object doesn't support any known hook methods, nor a string overload and is
also not a blessed CODE reference. In short the "require" function does not know what
to do with the object. See also "require" in perlfunc.
Attempt to call undefined %s method with arguments ("%s"%s) via package "%s" (Perhaps you
forgot to load the package?)
(D deprecated::missing_import_called_with_args) You called the import() or unimport()
method of a class that has no import method defined in its inheritance graph, and
passed an argument to the method. This is very often the sign of a mispelled package
name in a use or require statement that has silently succeded due to a case
insensitive file system.
Another common reason this may happen is when mistakenly attempting to import or
unimport a symbol from a class definition or package which does not use "Exporter" or
otherwise define its own "import" or "unimport" method.
Can't locate package %s for @%s::ISA
(W syntax) The @ISA array contained the name of another package that doesn't seem to
exist.
Can't locate PerlIO%s
(F) You tried to use in open() a PerlIO layer that does not exist, e.g. open(FH,
">:nosuchlayer", "somefile").
Can't make list assignment to %ENV on this system
(F) List assignment to %ENV is not supported on some systems, notably VMS.
Can't make loaded symbols global on this platform while loading %s
(S) A module passed the flag 0x01 to DynaLoader::dl_load_file() to request that
symbols from the stated file are made available globally within the process, but that
functionality is not available on this platform. Whilst the module likely will still
work, this may prevent the perl interpreter from loading other XS-based extensions
which need to link directly to functions defined in the C or XS code in the stated
file.
Can't modify %s in %s
(F) You aren't allowed to assign to the item indicated, or otherwise try to change it,
such as with an auto-increment.
Can't modify non-lvalue subroutine call of &%s
Can't modify non-lvalue subroutine call of &%s in %s
(F) Subroutines meant to be used in lvalue context should be declared as such. See
"Lvalue subroutines" in perlsub.
Can't modify reference to %s in %s assignment
(F) Only a limited number of constructs can be used as the argument to a reference
constructor on the left-hand side of an assignment, and what you used was not one of
them. See "Assigning to References" in perlref.
Can't modify reference to localized parenthesized array in list assignment
(F) Assigning to "\local(@array)" or "\(local @array)" is not supported, as it is not
clear exactly what it should do. If you meant to make @array refer to some other
array, use "\@array = \@other_array". If you want to make the elements of @array
aliases of the scalars referenced on the right-hand side, use "\(@array) =
@scalar_refs".
Can't modify reference to parenthesized hash in list assignment
(F) Assigning to "\(%hash)" is not supported. If you meant to make %hash refer to
some other hash, use "\%hash = \%other_hash". If you want to make the elements of
%hash into aliases of the scalars referenced on the right-hand side, use a hash slice:
"\@hash{@keys} = @those_scalar_refs".
Can't msgrcv to read-only var
(F) The target of a msgrcv must be modifiable to be used as a receive buffer.
Can't "next" outside a loop block
(F) A "next" statement was executed to reiterate the current block, but there isn't a
current block. Note that an "if" or "else" block doesn't count as a "loopish" block,
as doesn't a block given to sort(), map() or grep(). You can usually double the
curlies to get the same effect though, because the inner curlies will be considered a
block that loops once. See "next" in perlfunc.
Can't open %s: %s
(S inplace) The implicit opening of a file through use of the "<>" filehandle, either
implicitly under the "-n" or "-p" command-line switches, or explicitly, failed for the
indicated reason. Usually this is because you don't have read permission for a file
which you named on the command line.
(F) You tried to call perl with the -e switch, but /dev/null (or your operating
system's equivalent) could not be opened.
Can't open a reference
(W io) You tried to open a scalar reference for reading or writing, using the 3-arg
open() syntax:
open FH, '>', $ref;
but your version of perl is compiled without perlio, and this form of open is not
supported.
Can't open bidirectional pipe
(W pipe) You tried to say "open(CMD, "|cmd|")", which is not supported. You can try
any of several modules in the Perl library to do this, such as IPC::Open2.
Alternately, direct the pipe's output to a file using ">", and then read it in under a
different file handle.
Can't open error file %s as stderr
(F) An error peculiar to VMS. Perl does its own command line redirection, and
couldn't open the file specified after '2>' or '2>>' on the command line for writing.
Can't open input file %s as stdin
(F) An error peculiar to VMS. Perl does its own command line redirection, and
couldn't open the file specified after '<' on the command line for reading.
Can't open output file %s as stdout
(F) An error peculiar to VMS. Perl does its own command line redirection, and
couldn't open the file specified after '>' or '>>' on the command line for writing.
Can't open output pipe (name: %s)
(P) An error peculiar to VMS. Perl does its own command line redirection, and
couldn't open the pipe into which to send data destined for stdout.
Can't open perl script "%s": %s
(F) The script you specified can't be opened for the indicated reason.
If you're debugging a script that uses #!, and normally relies on the shell's $PATH
search, the -S option causes perl to do that search, so you don't have to type the
path or `which $scriptname`.
Can't read CRTL environ
(S) A warning peculiar to VMS. Perl tried to read an element of %ENV from the CRTL's
internal environment array and discovered the array was missing. You need to figure
out where your CRTL misplaced its environ or define PERL_ENV_TABLES (see perlvms) so
that environ is not searched.
Can't redeclare "%s" in "%s"
(F) A "my", "our" or "state" declaration was found within another declaration, such as
"my ($x, my($y), $z)" or "our (my $x)".
Can't "redo" outside a loop block
(F) A "redo" statement was executed to restart the current block, but there isn't a
current block. Note that an "if" or "else" block doesn't count as a "loopish" block,
as doesn't a block given to sort(), map() or grep(). You can usually double the
curlies to get the same effect though, because the inner curlies will be considered a
block that loops once. See "redo" in perlfunc.
Can't remove %s: %s, skipping file
(S inplace) You requested an inplace edit without creating a backup file. Perl was
unable to remove the original file to replace it with the modified file. The file was
left unmodified.
Can't rename in-place work file '%s' to '%s': %s
(F) When closed implicitly, the temporary file for in-place editing couldn't be
renamed to the original filename.
Can't rename %s to %s: %s, skipping file
(F) The rename done by the -i switch failed for some reason, probably because you
don't have write permission to the directory.
Can't reopen input pipe (name: %s) in binary mode
(P) An error peculiar to VMS. Perl thought stdin was a pipe, and tried to reopen it
to accept binary data. Alas, it failed.
Can't represent character for Ox%X on this platform
(F) There is a hard limit to how big a character code point can be due to the
fundamental properties of UTF-8, especially on EBCDIC platforms. The given code point
exceeds that. The only work-around is to not use such a large code point.
Can't reset %ENV on this system
(F) You called reset('E') or similar, which tried to reset all variables in the
current package beginning with "E". In the main package, that includes %ENV.
Resetting %ENV is not supported on some systems, notably VMS.
Can't resolve method "%s" overloading "%s" in package "%s"
(F)(P) Error resolving overloading specified by a method name (as opposed to a
subroutine reference): no such method callable via the package. If the method name is
"???", this is an internal error.
Can't return %s from lvalue subroutine
(F) Perl detected an attempt to return illegal lvalues (such as temporary or readonly
values) from a subroutine used as an lvalue. This is not allowed.
Can't return outside a subroutine
(F) The return statement was executed in mainline code, that is, where there was no
subroutine call to return out of. See perlsub.
Can't return %s to lvalue scalar context
(F) You tried to return a complete array or hash from an lvalue subroutine, but you
called the subroutine in a way that made Perl think you meant to return only one
value. You probably meant to write parentheses around the call to the subroutine,
which tell Perl that the call should be in list context.
Can't take log of %g
(F) For ordinary real numbers, you can't take the logarithm of a negative number or
zero. There's a Math::Complex package that comes standard with Perl, though, if you
really want to do that for the negative numbers.
Can't take sqrt of %g
(F) For ordinary real numbers, you can't take the square root of a negative number.
There's a Math::Complex package that comes standard with Perl, though, if you really
want to do that.
Can't undef active subroutine
(F) You can't undefine a routine that's currently running. You can, however, redefine
it while it's running, and you can even undef the redefined subroutine while the old
routine is running. Go figure.
Can't unweaken a nonreference
(F) You attempted to unweaken something that was not a reference. Only references can
be unweakened.
Can't upgrade %s (%d) to %d
(P) The internal sv_upgrade routine adds "members" to an SV, making it into a more
specialized kind of SV. The top several SV types are so specialized, however, that
they cannot be interconverted. This message indicates that such a conversion was
attempted.
Can't use '%c' after -mname
(F) You tried to call perl with the -m switch, but you put something other than "="
after the module name.
Can't use a hash as a reference
(F) You tried to use a hash as a reference, as in "%foo->{"bar"}" or
"%$ref->{"hello"}". Versions of perl <= 5.22.0 used to allow this syntax, but
shouldn't have. This was deprecated in perl 5.6.1.
Can't use an array as a reference
(F) You tried to use an array as a reference, as in "@foo->[23]" or "@$ref->[99]".
Versions of perl <= 5.22.0 used to allow this syntax, but shouldn't have. This was
deprecated in perl 5.6.1.
Can't use anonymous symbol table for method lookup
(F) The internal routine that does method lookup was handed a symbol table that
doesn't have a name. Symbol tables can become anonymous for example by undefining
stashes: "undef %Some::Package::".
Can't use an undefined value as %s reference
(F) A value used as either a hard reference or a symbolic reference must be a defined
value. This helps to delurk some insidious errors.
Can't use bareword ("%s") as %s ref while "strict refs" in use
(F) Only hard references are allowed by "strict refs". Symbolic references are
disallowed. See perlref.
Can't use %! because Errno.pm is not available
(F) The first time the "%!" hash is used, perl automatically loads the Errno.pm
module. The Errno module is expected to tie the %! hash to provide symbolic names for
$! errno values.
Can't use both '<' and '>' after type '%c' in %s
(F) A type cannot be forced to have both big-endian and little-endian byte-order at
the same time, so this combination of modifiers is not allowed. See "pack" in
perlfunc.
Can't use 'defined(@array)' (Maybe you should just omit the defined()?)
(F) defined() is not useful on arrays because it checks for an undefined scalar value.
If you want to see if the array is empty, just use "if (@array) { # not empty }" for
example.
Can't use 'defined(%hash)' (Maybe you should just omit the defined()?)
(F) defined() is not usually right on hashes.
Although "defined %hash" is false on a plain not-yet-used hash, it becomes true in
several non-obvious circumstances, including iterators, weak references, stash names,
even remaining true after "undef %hash". These things make "defined %hash" fairly
useless in practice, so it now generates a fatal error.
If a check for non-empty is what you wanted then just put it in boolean context (see
"Scalar values" in perldata):
if (%hash) {
# not empty
}
If you had "defined %Foo::Bar::QUUX" to check whether such a package variable exists
then that's never really been reliable, and isn't a good way to enquire about the
features of a package, or whether it's loaded, etc.
Can't use %s for loop variable
(P) The parser got confused when trying to parse a "foreach" loop.
Can't use global %s in %s
(F) You tried to declare a magical variable as a lexical variable. This is not
allowed, because the magic can be tied to only one location (namely the global
variable) and it would be incredibly confusing to have variables in your program that
looked like magical variables but weren't.
Can't use '%c' in a group with different byte-order in %s
(F) You attempted to force a different byte-order on a type that is already inside a
group with a byte-order modifier. For example you cannot force little-endianness on a
type that is inside a big-endian group.
Can't use "my %s" in sort comparison
(F) The global variables $a and $b are reserved for sort comparisons. You mentioned
$a or $b in the same line as the <=> or cmp operator, and the variable had earlier
been declared as a lexical variable. Either qualify the sort variable with the
package name, or rename the lexical variable.
Can't use %s ref as %s ref
(F) You've mixed up your reference types. You have to dereference a reference of the
type needed. You can use the ref() function to test the type of the reference, if
need be.
Can't use string ("%s") as %s ref while "strict refs" in use
Can't use string ("%s"...) as %s ref while "strict refs" in use
(F) You've told Perl to dereference a string, something which "use strict" blocks to
prevent it happening accidentally. See "Symbolic references" in perlref. This can be
triggered by an "@" or "$" in a double-quoted string immediately before interpolating
a variable, for example in "user @$twitter_id", which says to treat the contents of
$twitter_id as an array reference; use a "\" to have a literal "@" symbol followed by
the contents of $twitter_id: "user \@$twitter_id".
Can't use subscript on %s
(F) The compiler tried to interpret a bracketed expression as a subscript. But to the
left of the brackets was an expression that didn't look like a hash or array
reference, or anything else subscriptable.
Can't use \%c to mean $%c in expression
(W syntax) In an ordinary expression, backslash is a unary operator that creates a
reference to its argument. The use of backslash to indicate a backreference to a
matched substring is valid only as part of a regular expression pattern. Trying to do
this in ordinary Perl code produces a value that prints out looking like
SCALAR(0xdecaf). Use the $1 form instead.
Can't weaken a nonreference
(F) You attempted to weaken something that was not a reference. Only references can
be weakened.
Can't "when" outside a topicalizer
(F) You have used a when() block that is neither inside a "foreach" loop nor a "given"
block. (Note that this error is issued on exit from the "when" block, so you won't
get the error if the match fails, or if you use an explicit "continue".)
Can't x= to read-only value
(F) You tried to repeat a constant value (often the undefined value) with an
assignment operator, which implies modifying the value itself. Perhaps you need to
copy the value to a temporary, and repeat that.
catch block requires a (VAR)
(F) You tried to use the "try" and "catch" syntax of "use feature 'try'" but did not
include the error variable in the "catch" block. The parenthesized variable name is
not optional, unlike in some other forms of syntax you may be familiar with from CPAN
modules or other languages.
The required syntax is
try { ... }
catch ($var) { ... }
Changing use VERSION while another use VERSION is in scope is now deprecated
(W deprecated) Once you have a "use VERSION" statement in scope, any "use VERSION"
statement that requests a different version is now deprecated, due to the increasing
complexity of swapping from one prevailing version to another.
It is suggested that you do not try to mix multiple different version declarations
within the same file as it leads to complex behaviours about the visibility of
features and builtin functions, as well as confusing human readers.
If it is essential to have different "use VERSION" declarations in different regions
of the same file, you should surround each one by its own enclosing scope so the two
do not mix.
{
use v5.20;
...
}
{
use v5.36;
...
}
Character following "\c" must be printable ASCII
(F) In "\cX", X must be a printable (non-control) ASCII character.
Note that ASCII characters that don't map to control characters are discouraged, and
will generate the warning (when enabled) ""\c%c" is more clearly written simply as
"%s"".
Character following \%c must be '{' or a single-character Unicode property name in regex;
marked by <-- HERE in m/%s/
(F) (In the above the %c is replaced by either "p" or "P".) You specified something
that isn't a legal Unicode property name. Most Unicode properties are specified by
"\p{...}". But if the name is a single character one, the braces may be omitted.
Character in 'C' format wrapped in pack
(W pack) You said
pack("C", $x)
where $x is either less than 0 or more than 255; the "C" format is only for encoding
native operating system characters (ASCII, EBCDIC, and so on) and not for Unicode
characters, so Perl behaved as if you meant
pack("C", $x & 255)
If you actually want to pack Unicode codepoints, use the "U" format instead.
Character in 'c' format wrapped in pack
(W pack) You said
pack("c", $x)
where $x is either less than -128 or more than 127; the "c" format is only for
encoding native operating system characters (ASCII, EBCDIC, and so on) and not for
Unicode characters, so Perl behaved as if you meant
pack("c", $x & 255);
If you actually want to pack Unicode codepoints, use the "U" format instead.
Character in '%c' format wrapped in unpack
(W unpack) You tried something like
unpack("H", "\x{2a1}")
where the format expects to process a byte (a character with a value below 256), but a
higher value was provided instead. Perl uses the value modulus 256 instead, as if you
had provided:
unpack("H", "\x{a1}")
Character in 'W' format wrapped in pack
(W pack) You said
pack("U0W", $x)
where $x is either less than 0 or more than 255. However, "U0"-mode expects all
values to fall in the interval [0, 255], so Perl behaved as if you meant:
pack("U0W", $x & 255)
Character(s) in '%c' format wrapped in pack
(W pack) You tried something like
pack("u", "\x{1f3}b")
where the format expects to process a sequence of bytes (character with a value below
256), but some of the characters had a higher value. Perl uses the character values
modulus 256 instead, as if you had provided:
pack("u", "\x{f3}b")
Character(s) in '%c' format wrapped in unpack
(W unpack) You tried something like
unpack("s", "\x{1f3}b")
where the format expects to process a sequence of bytes (character with a value below
256), but some of the characters had a higher value. Perl uses the character values
modulus 256 instead, as if you had provided:
unpack("s", "\x{f3}b")
charnames alias definitions may not contain a sequence of multiple spaces; marked by
<-- HERE in %s
(F) You defined a character name which had multiple space characters in a row. Change
them to single spaces. Usually these names are defined in the ":alias" import
argument to "use charnames", but they could be defined by a translator installed into
$^H{charnames}. See "CUSTOM ALIASES" in charnames.
chdir() on unopened filehandle %s
(W unopened) You tried chdir() on a filehandle that was never opened.
"\c%c" is more clearly written simply as "%s"
(W syntax) The "\cX" construct is intended to be a way to specify non-printable
characters. You used it for a printable one, which is better written as simply
itself, perhaps preceded by a backslash for non-word characters. Doing it the way you
did is not portable between ASCII and EBCDIC platforms.
Class already has a superclass, cannot add another
(F) You attempted to specify a second superclass for a "class" by using the ":isa"
attribute, when one is already specified. Unlike classes whose instances are created
with "bless", classes created via the "class" keyword cannot have more than one
superclass.
Class attribute %s requires a value
(F) You specified an attribute for a class that would require a value to be passed in
parentheses, but did not provide one. Remember that whitespace is not permitted
between the attribute name and its value; you must write this as
class Example::Class :attr(VALUE) ...
class is experimental
(S experimental::class) This warning is emitted if you use the "class" keyword of "use
feature 'class'". This keyword is currently experimental and its behaviour may change
in future releases of Perl.
Class :isa attribute requires a class but "%s" is not one
(F) When creating a subclass using the "class" ":isa" attribute, the named superclass
must also be a real class created using the "class" keyword.
Cloning substitution context is unimplemented
(F) Creating a new thread inside the "s///" operator is not supported.
closedir() attempted on invalid dirhandle %s
(W io) The dirhandle you tried to close is either closed or not really a dirhandle.
Check your control flow.
close() on unopened filehandle %s
(W unopened) You tried to close a filehandle that was never opened.
Closure prototype called
(F) If a closure has attributes, the subroutine passed to an attribute handler is the
prototype that is cloned when a new closure is created. This subroutine cannot be
called.
\C no longer supported in regex; marked by <-- HERE in m/%s/
(F) The \C character class used to allow a match of single byte within a multi-byte
utf-8 character, but was removed in v5.24 as it broke encapsulation and its
implementation was extremely buggy. If you really need to process the individual
bytes, you probably want to convert your string to one where each underlying byte is
stored as a character, with utf8::encode().
Code missing after '/'
(F) You had a (sub-)template that ends with a '/'. There must be another template
code following the slash. See "pack" in perlfunc.
Code point 0x%X is not Unicode, and not portable
(S non_unicode portable) You had a code point that has never been in any standard, so
it is likely that languages other than Perl will NOT understand it. This code point
also will not fit in a 32-bit word on ASCII platforms and therefore is non-portable
between systems.
At one time, it was legal in some standards to have code points up to 0x7FFF_FFFF, but
not higher, and this code point is higher.
Acceptance of these code points is a Perl extension, and you should expect that
nothing other than Perl can handle them; Perl itself on EBCDIC platforms before v5.24
does not handle them.
Perl also makes no guarantees that the representation of these code points won't
change at some point in the future, say when machines become available that have
larger than a 64-bit word. At that time, files containing any of these, written by an
older Perl might require conversion before being readable by a newer Perl.
Code point 0x%X is not Unicode, may not be portable
(S non_unicode) You had a code point above the Unicode maximum of U+10FFFF.
Perl allows strings to contain a superset of Unicode code points, but these may not be
accepted by other languages/systems. Further, even if these languages/systems accept
these large code points, they may have chosen a different representation for them than
the UTF-8-like one that Perl has, which would mean files are not exchangeable between
them and Perl.
On EBCDIC platforms, code points above 0x3FFF_FFFF have a different representation in
Perl v5.24 than before, so any file containing these that was written before that
version will require conversion before being readable by a later Perl.
%s: Command not found
(A) You've accidentally run your script through csh or another shell instead of Perl.
Check the #! line, or manually feed your script into Perl yourself. The #! line at
the top of your file could look like
#!/usr/bin/perl
%s: command not found
(A) You've accidentally run your script through bash or another shell instead of Perl.
Check the #! line, or manually feed your script into Perl yourself. The #! line at
the top of your file could look like
#!/usr/bin/perl
%s: command not found: %s
(A) You've accidentally run your script through zsh or another shell instead of Perl.
Check the #! line, or manually feed your script into Perl yourself. The #! line at
the top of your file could look like
#!/usr/bin/perl
Compilation failed in require
(F) Perl could not compile a file specified in a "require" statement. Perl uses this
generic message when none of the errors that it encountered were severe enough to halt
compilation immediately.
connect() on closed socket %s
(W closed) You tried to do a connect on a closed socket. Did you forget to check the
return value of your socket() call? See "connect" in perlfunc.
Constant(%s): Call to &{$^H{%s}} did not return a defined value
(F) The subroutine registered to handle constant overloading (see overload) or a
custom charnames handler (see "CUSTOM TRANSLATORS" in charnames) returned an undefined
value.
Constant(%s): $^H{%s} is not defined
(F) The parser found inconsistencies while attempting to define an overloaded
constant. Perhaps you forgot to load the corresponding overload pragma?
Constant is not %s reference
(F) A constant value (perhaps declared using the "use constant" pragma) is being
dereferenced, but it amounts to the wrong type of reference. The message indicates
the type of reference that was expected. This usually indicates a syntax error in
dereferencing the constant value. See "Constant Functions" in perlsub and constant.
Constants from lexical variables potentially modified elsewhere are no longer permitted
(F) You wrote something like
my $var;
$sub = sub () { $var };
but $var is referenced elsewhere and could be modified after the "sub" expression is
evaluated. Either it is explicitly modified elsewhere ("$var = 3") or it is passed to
a subroutine or to an operator like "printf" or "map", which may or may not modify the
variable.
Traditionally, Perl has captured the value of the variable at that point and turned
the subroutine into a constant eligible for inlining. In those cases where the
variable can be modified elsewhere, this breaks the behavior of closures, in which the
subroutine captures the variable itself, rather than its value, so future changes to
the variable are reflected in the subroutine's return value.
This usage was deprecated, and as of Perl 5.32 is no longer allowed, making it
possible to change the behavior in the future.
If you intended for the subroutine to be eligible for inlining, then make sure the
variable is not referenced elsewhere, possibly by copying it:
my $var2 = $var;
$sub = sub () { $var2 };
If you do want this subroutine to be a closure that reflects future changes to the
variable that it closes over, add an explicit "return":
my $var;
$sub = sub () { return $var };
Constant subroutine %s redefined
(W redefine)(S) You redefined a subroutine which had previously been eligible for
inlining. See "Constant Functions" in perlsub for commentary and workarounds.
Constant subroutine %s undefined
(W misc) You undefined a subroutine which had previously been eligible for inlining.
See "Constant Functions" in perlsub for commentary and workarounds.
Constant(%s) unknown
(F) The parser found inconsistencies either while attempting to define an overloaded
constant, or when trying to find the character name specified in the "\N{...}" escape.
Perhaps you forgot to load the corresponding overload pragma?
:const is not permitted on named subroutines
(F) The "const" attribute causes an anonymous subroutine to be run and its value
captured at the time that it is cloned. Named subroutines are not cloned like this,
so the attribute does not make sense on them.
Copy method did not return a reference
(F) The method which overloads "=" is buggy. See "Copy Constructor" in overload.
&CORE::%s cannot be called directly
(F) You tried to call a subroutine in the "CORE::" namespace with &foo syntax or
through a reference. Some subroutines in this package cannot yet be called that way,
but must be called as barewords. Something like this will work:
BEGIN { *shove = \&CORE::push; }
shove @array, 1,2,3; # pushes on to @array
CORE::%s is not a keyword
(F) The CORE:: namespace is reserved for Perl keywords.
Corrupted regexp opcode %d > %d
(P) This is either an error in Perl, or, if you're using one, your custom regular
expression engine. If not the latter, report the problem to
<https://github.com/Perl/perl5/issues/new/choose>.
corrupted regexp pointers
(P) The regular expression engine got confused by what the regular expression compiler
gave it.
corrupted regexp program
(P) The regular expression engine got passed a regexp program without a valid magic
number.
Corrupt malloc ptr 0x%x at 0x%x
(P) The malloc package that comes with Perl had an internal failure.
Count after length/code in unpack
(F) You had an unpack template indicating a counted-length string, but you have also
specified an explicit size for the string. See "pack" in perlfunc.
Declaring references is experimental
(S experimental::declared_refs) This warning is emitted if you use a reference
constructor on the right-hand side of "my", "state", "our", or "local". Simply
suppress the warning if you want to use the feature, but know that in doing so you are
taking the risk of using an experimental feature which may change or be removed in a
future Perl version:
no warnings "experimental::declared_refs";
use feature "declared_refs";
$fooref = my \$foo;
Deep recursion on anonymous subroutine
Deep recursion on subroutine "%s"
(W recursion) This subroutine has called itself (directly or indirectly) 100 times
more than it has returned. This probably indicates an infinite recursion, unless
you're writing strange benchmark programs, in which case it indicates something else.
This threshold can be changed from 100, by recompiling the perl binary, setting the C
pre-processor macro "PERL_SUB_DEPTH_WARN" to the desired value.
(?(DEFINE)....) does not allow branches in regex; marked by <-- HERE in m/%s/
(F) You used something like "(?(DEFINE)...|..)" which is illegal. The most likely
cause of this error is that you left out a parenthesis inside of the "...." part.
The <-- HERE shows whereabouts in the regular expression the problem was discovered.
%s defines neither package nor VERSION--version check failed
(F) You said something like "use Module 42" but in the Module file there are neither
package declarations nor a $VERSION.
delete argument is not a HASH or ARRAY element or slice
(F) The argument to "delete" must be either a hash or array element, such as:
$foo{$bar}
$ref->{"susie"}[12]
or a hash or array slice, such as:
@foo[$bar, $baz, $xyzzy]
$ref->[12]->@{"susie", "queue"}
or a hash key/value or array index/value slice, such as:
%foo[$bar, $baz, $xyzzy]
$ref->[12]->%{"susie", "queue"}
Delimiter for here document is too long
(F) In a here document construct like "<<FOO", the label "FOO" is too long for Perl to
handle. You have to be seriously twisted to write code that triggers this error.
DESTROY created new reference to dead object '%s'
(F) A DESTROY() method created a new reference to the object which is just being
DESTROYed. Perl is confused, and prefers to abort rather than to create a dangling
reference.
Did not produce a valid header
See "500 Server error".
%s did not return a true value
(F) A required (or used) file must return a true value to indicate that it compiled
correctly and ran its initialization code correctly. It's traditional to end such a
file with a "1;", though any true value would do. See "require" in perlfunc.
(Did you mean &%s instead?)
(W misc) You probably referred to an imported subroutine &FOO as $FOO or some such.
(Did you mean "local" instead of "our"?)
(W shadow) Remember that "our" does not localize the declared global variable. You
have declared it again in the same lexical scope, which seems superfluous.
(Did you mean $ or @ instead of %?)
(W) You probably said %hash{$key} when you meant $hash{$key} or @hash{@keys}. On the
other hand, maybe you just meant %hash and got carried away.
Died
(F) You passed die() an empty string (the equivalent of "die """) or you called it
with no args and $@ was empty.
Document contains no data
See "500 Server error".
%s does not define %s::VERSION--version check failed
(F) You said something like "use Module 42" but the Module did not define a $VERSION.
'/' does not take a repeat count in %s
(F) You cannot put a repeat count of any kind right after the '/' code. See "pack" in
perlfunc.
do "%s" failed, '.' is no longer in @INC; did you mean do "./%s"?
(D deprecated::dot_in_inc) Previously " do "somefile"; " would search the current
directory for the specified file. Since perl v5.26.0, . has been removed from @INC by
default, so this is no longer true. To search the current directory (and only the
current directory) you can write " do "./somefile"; ".
'%s' does not appear to be an imported builtin function
(F) An attempt was made to remove a previously-imported lexical from builtin by using
the "unimport" method (likely via "no builtin ..." syntax), but the requested
function has not been imported into the current scope.
Don't know how to get file name
(P) "PerlIO_getname", a perl internal I/O function specific to VMS, was somehow called
on another platform. This should not happen.
Don't know how to handle magic of type \%o
(P) The internal handling of magical variables has been cursed.
Downgrading a use VERSION declaration to below v5.11 is not permitted
(F) A "use VERSION" statement that requests a version below v5.11 (when the effects of
"use strict" would be disabled) has been found after a previous declaration of one
having a larger number (which would have enabled these effects). Because of a change
to the way that "use VERSION" interacts with the strictness flags, this is no longer
supported.
(Do you need to predeclare %s?)
(S syntax) This is an educated guess made in conjunction with the message "%s found
where operator expected". It often means a subroutine or module name is being
referenced that hasn't been declared yet. This may be because of ordering problems in
your file, or because of a missing "sub", "package", "require", or "use" statement.
If you're referencing something that isn't defined yet, you don't actually have to
define the subroutine or package before the current location. You can use an empty
"sub foo;" or "package FOO;" to enter a "forward" declaration.
dump() must be written as CORE::dump() as of Perl 5.30
(F) You used the obsolete dump() built-in function. That was deprecated in Perl
5.8.0. As of Perl 5.30 it must be written in fully qualified format: CORE::dump().
See "dump" in perlfunc.
dump is not supported
(F) Your machine doesn't support dump/undump.
Duplicate free() ignored
(S malloc) An internal routine called free() on something that had already been freed.
Duplicate modifier '%c' after '%c' in %s
(W unpack) You have applied the same modifier more than once after a type in a pack
template. See "pack" in perlfunc.
each on anonymous %s will always start from the beginning
(W syntax) You called each on an anonymous hash or array. Since a new hash or array
is created each time, each() will restart iterating over your hash or array every
time.
elseif should be elsif
(S syntax) There is no keyword "elseif" in Perl because Larry thinks it's ugly. Your
code will be interpreted as an attempt to call a method named "elseif" for the class
returned by the following block. This is unlikely to be what you want.
Empty \%c in regex; marked by <-- HERE in m/%s/
Empty \%c{}
Empty \%c{} in regex; marked by <-- HERE in m/%s/
(F) You used something like "\b{}", "\B{}", "\o{}", "\p", "\P", or "\x" without
specifying anything for it to operate on.
Unfortunately, for backwards compatibility reasons, an empty "\x" is legal outside
"use re 'strict'" and expands to a NUL character.
Empty (?) without any modifiers in regex; marked by <-- HERE in m/%s/
(W regexp) (only under "use re 'strict'") "(?)" does nothing, so perhaps this is a
typo.
${^ENCODING} is no longer supported
(F) The special variable "${^ENCODING}", formerly used to implement the "encoding"
pragma, is no longer supported as of Perl 5.26.0.
Setting it to anything other than "undef" is a fatal error as of Perl 5.28.
${^HOOK}{%s} may only be a CODE reference or undef
(F) You attempted to assign something other than undef or a CODE ref to "%{^HOOK}".
Hooks may only be CODE refs. See "%{^HOOK}" in perlvar for details.
Attempt to set unknown hook '%s' in %{^HOOK}
(F) You attempted to assign something other than undef or a CODE ref to "%{^HOOK}".
Hooks may only be CODE refs. See "%{^HOOK}" in perlvar for details.
entering effective %s failed
(F) While under the "use filetest" pragma, switching the real and effective uids or
gids failed.
%ENV is aliased to %s
(F) You're running under taint mode, and the %ENV variable has been aliased to another
hash, so it doesn't reflect anymore the state of the program's environment. This is
potentially insecure.
Error converting file specification %s
(F) An error peculiar to VMS. Because Perl may have to deal with file specifications
in either VMS or Unix syntax, it converts them to a single form when it must operate
on them directly. Either you've passed an invalid file specification to Perl, or
you've found a case the conversion routines don't handle. Drat.
Error %s in expansion of %s
(F) An error was encountered in handling a user-defined property ("User-Defined
Character Properties" in perlunicode). These are programmer written subroutines,
hence subject to errors that may prevent them from compiling or running. The calls to
these subs are "eval"'d, and if there is a failure, this message is raised, using the
contents of $@ from the failed "eval".
Another possibility is that tainted data was encountered somewhere in the chain of
expanding the property. If so, the message wording will indicate that this is the
problem. See "Insecure user-defined property %s".
Eval-group in insecure regular expression
(F) Perl detected tainted data when trying to compile a regular expression that
contains the "(?{ ... })" zero-width assertion, which is unsafe. See "(?{ code })" in
perlre, and perlsec.
Eval-group not allowed at runtime, use re 'eval' in regex m/%s/
(F) Perl tried to compile a regular expression containing the "(?{ ... })" zero-width
assertion at run time, as it would when the pattern contains interpolated values.
Since that is a security risk, it is not allowed. If you insist, you may still do
this by using the "re 'eval'" pragma or by explicitly building the pattern from an
interpolated string at run time and using that in an eval(). See "(?{ code })" in
perlre.
Eval-group not allowed, use re 'eval' in regex m/%s/
(F) A regular expression contained the "(?{ ... })" zero-width assertion, but that
construct is only allowed when the "use re 'eval'" pragma is in effect. See "(?{ code
})" in perlre.
EVAL without pos change exceeded limit in regex; marked by <-- HERE in m/%s/
(F) You used a pattern that nested too many EVAL calls without consuming any text.
Restructure the pattern so that text is consumed.
The <-- HERE shows whereabouts in the regular expression the problem was discovered.
Excessively long <> operator
(F) The contents of a <> operator may not exceed the maximum size of a Perl
identifier. If you're just trying to glob a long list of filenames, try using the
glob() operator, or put the filenames into a variable and glob that.
exec? I'm not *that* kind of operating system
(F) The "exec" function is not implemented on some systems, e.g. Catamount. See
perlport.
%sExecution of %s aborted due to compilation errors.
(F) The final summary message when a Perl compilation fails.
Execution of %s aborted due to compilation errors.
(F) The final summary message when a Perl compilation fails.
exists argument is not a HASH or ARRAY element or a subroutine
(F) The argument to "exists" must be a hash or array element or a subroutine with an
ampersand, such as:
$foo{$bar}
$ref->{"susie"}[12]
&do_something
exists argument is not a subroutine name
(F) The argument to "exists" for "exists &sub" must be a subroutine name, and not a
subroutine call. "exists &sub()" will generate this error.
Exiting eval via %s
(W exiting) You are exiting an eval by unconventional means, such as a goto, or a loop
control statement.
Exiting format via %s
(W exiting) You are exiting a format by unconventional means, such as a goto, or a
loop control statement.
Exiting pseudo-block via %s
(W exiting) You are exiting a rather special block construct (like a sort block or
subroutine) by unconventional means, such as a goto, or a loop control statement. See
"sort" in perlfunc.
Exiting subroutine via %s
(W exiting) You are exiting a subroutine by unconventional means, such as a goto, or a
loop control statement.
Exiting substitution via %s
(W exiting) You are exiting a substitution by unconventional means, such as a return,
a goto, or a loop control statement.
Expected %s reference in export_lexically
(F) The type of a reference given to "export_lexically" in builtin did not match the
sigil of the preceding name, or the value was not a reference at all.
Expecting close bracket in regex; marked by <-- HERE in m/%s/
(F) You wrote something like
(?13
to denote a capturing group of the form "(?PARNO)", but omitted the ")".
Expecting interpolated extended charclass in regex; marked by <-- HERE in m/%s/
(F) It looked like you were attempting to interpolate an already-compiled extended
character class, like so:
my $thai_or_lao = qr/(?[ \p{Thai} + \p{Lao} ])/;
...
qr/(?[ \p{Digit} & $thai_or_lao ])/;
But the marked code isn't syntactically correct to be such an interpolated class.
Experimental aliasing via reference not enabled
(F) To do aliasing via references, you must first enable the feature:
no warnings "experimental::refaliasing";
use feature "refaliasing";
\$x = \$y;
Experimental %s on scalar is now forbidden
(F) An experimental feature added in Perl 5.14 allowed "each", "keys", "push", "pop",
"shift", "splice", "unshift", and "values" to be called with a scalar argument. This
experiment is considered unsuccessful, and has been removed. The "postderef" feature
may meet your needs better.
Experimental subroutine signatures not enabled
(F) To use subroutine signatures, you must first enable them:
use feature "signatures";
sub foo ($left, $right) { ... }
Explicit blessing to '' (assuming package main)
(W misc) You are blessing a reference to a zero length string. This has the effect of
blessing the reference into the package main. This is usually not what you want.
Consider providing a default target package, e.g. bless($ref, $p || 'MyPackage');
export_lexically can only be called at compile time
(F) "export_lexically" in builtin was called at runtime. Because it creates new names
in the lexical scope currently being compiled, it can only be called from code inside
"BEGIN" block in that scope.
%s: Expression syntax
(A) You've accidentally run your script through csh instead of Perl. Check the #!
line, or manually feed your script into Perl yourself.
%s failed--call queue aborted
(F) An untrapped exception was raised while executing a UNITCHECK, CHECK, INIT, or END
subroutine. Processing of the remainder of the queue of such routines has been
prematurely ended.
Failed to close in-place work file %s: %s
(F) Closing an output file from in-place editing, as with the "-i" command-line
switch, failed.
False [] range "%s" in regex; marked by <-- HERE in m/%s/
(W regexp)(F) A character class range must start and end at a literal character, not
another character class like "\d" or "[:alpha:]". The "-" in your false range is
interpreted as a literal "-". In a "(?[...])" construct, this is an error, rather
than a warning. Consider quoting the "-", "\-". The <-- HERE shows whereabouts in
the regular expression the problem was discovered. See perlre.
Fatal VMS error (status=%d) at %s, line %d
(P) An error peculiar to VMS. Something untoward happened in a VMS system service or
RTL routine; Perl's exit status should provide more details. The filename in "at %s"
and the line number in "line %d" tell you which section of the Perl source code is
distressed.
fcntl is not implemented
(F) Your machine apparently doesn't implement fcntl(). What is this, a PDP-11 or
something?
FETCHSIZE returned a negative value
(F) A tied array claimed to have a negative number of elements, which is not possible.
Field already has a parameter name, cannot add another
(F) A field may have at most one application of the ":param" attribute to assign a
parameter name to it; once applied a second one is not allowed.
Field attribute %s requires a value
(F) You specified an attribute for a field that would require a value to be passed in
parentheses, but did not provide one. Remember that whitespace is not permitted
between the attribute name and its value; you must write this as
field $var :attr(VALUE) ...
field is experimental
(S experimental::class) This warning is emitted if you use the "field" keyword of "use
feature 'class'". This keyword is currently experimental and its behaviour may change
in future releases of Perl.
Field %s is not accessible outside a method
(F) An attempt was made to access a field variable of a class from code that does not
appear inside the body of a "method" subroutine. This is not permitted, as only
methods will have access to the fields of an instance.
Field %s of "%s" is not accessible in a method of "%s"
(F) An attempt was made to access a field variable of a class, from a method of
another class nested inside the one that actually defined it. This is not permitted,
as only methods defined by a given class are permitted to access fields of that class.
Field too wide in 'u' format in pack
(W pack) Each line in an uuencoded string starts with a length indicator which can't
encode values above 63. So there is no point in asking for a line length bigger than
that. Perl will behave as if you specified "u63" as the format.
Filehandle %s opened only for input
(W io) You tried to write on a read-only filehandle. If you intended it to be a read-
write filehandle, you needed to open it with "+<" or "+>" or "+>>" instead of with "<"
or nothing. If you intended only to write the file, use ">" or ">>". See "open" in
perlfunc.
Filehandle %s opened only for output
(W io) You tried to read from a filehandle opened only for writing, If you intended it
to be a read/write filehandle, you needed to open it with "+<" or "+>" or "+>>"
instead of with ">". If you intended only to read from the file, use "<". See "open"
in perlfunc. Another possibility is that you attempted to open filedescriptor 0 (also
known as STDIN) for output (maybe you closed STDIN earlier?).
Filehandle %s reopened as %s only for input
(W io) You opened for reading a filehandle that got the same filehandle id as STDOUT
or STDERR. This occurred because you closed STDOUT or STDERR previously.
Filehandle STDIN reopened as %s only for output
(W io) You opened for writing a filehandle that got the same filehandle id as STDIN.
This occurred because you closed STDIN previously.
Filehandle STD%s reopened as %s only for input
(W io) You opened for reading a filehandle that got the same filehandle id as STDOUT
or STDERR. This occurred because you closed the handle previously.
Final $ should be \$ or $name
(F) You must now decide whether the final $ in a string was meant to be a literal
dollar sign, or was meant to introduce a variable name that happens to be missing. So
you have to put either the backslash or the name.
defer is experimental
(S experimental::defer) The "defer" block modifier is experimental. If you want to use
the feature, disable the warning with "no warnings 'experimental::defer'", but know
that in doing so you are taking the risk that your code may break in a future Perl
version.
flock() on closed filehandle %s
(W closed) The filehandle you're attempting to flock() got itself closed some time
before now. Check your control flow. flock() operates on filehandles. Are you
attempting to call flock() on a dirhandle by the same name?
for my (...) is experimental
(S experimental::for_list) This warning is emitted if you use "for" to iterate
multiple values at a time. This syntax is currently experimental and its behaviour may
change in future releases of Perl.
Forked open '%s' not meaningful in <>
(S inplace) You had "|-" or "-|" in @ARGV and tried to use "<>" to read from it.
Previously this would fork and produce a confusing error message.
Format not terminated
(F) A format must be terminated by a line with a solitary dot. Perl got to the end of
your file without finding such a line.
Format %s redefined
(W redefine) You redefined a format. To suppress this warning, say
{
no warnings 'redefine';
eval "format NAME =...";
}
Found = in conditional, should be ==
(W syntax) You said
if ($foo = 123)
when you meant
if ($foo == 123)
(or something like that).
%s found where operator expected
(S syntax) The Perl lexer knows whether to expect a term or an operator. If it sees
what it knows to be a term when it was expecting to see an operator, it gives you this
warning. Usually it indicates that an operator or delimiter was omitted, such as a
semicolon.
gdbm store returned %d, errno %d, key "%s"
(S) A warning from the GDBM_File extension that a store failed.
gethostent not implemented
(F) Your C library apparently doesn't implement gethostent(), probably because if it
did, it'd feel morally obligated to return every hostname on the Internet.
get%sname() on closed socket %s
(W closed) You tried to get a socket or peer socket name on a closed socket. Did you
forget to check the return value of your socket() call?
getpwnam returned invalid UIC %#o for user "%s"
(S) A warning peculiar to VMS. The call to "sys$getuai" underlying the "getpwnam"
operator returned an invalid UIC.
getsockopt() on closed socket %s
(W closed) You tried to get a socket option on a closed socket. Did you forget to
check the return value of your socket() call? See "getsockopt" in perlfunc.
get_layers: unknown argument '%s'
(F) You called PerlIO::get_layers() with an unknown argument. Legal arguments are
provided in key/value pairs, with the keys being one of "input", "output" or "detail",
followed by a boolean.
given is deprecated
(D deprecated::smartmatch) "given" depends on smartmatch, which is deprecated. It will
be removed in Perl 5.42. See the explanation under "Experimental Details on given and
when" in perlsyn.
Global symbol "%s" requires explicit package name (did you forget to declare "my %s"?)
(F) You've said "use strict" or "use strict vars", which indicates that all variables
must either be lexically scoped (using "my" or "state"), declared beforehand using
"our", or explicitly qualified to say which package the global variable is in (using
"::").
glob failed (%s)
(S glob) Something went wrong with the external program(s) used for "glob" and
"<*.c>". Usually, this means that you supplied a "glob" pattern that caused the
external program to fail and exit with a nonzero status. If the message indicates
that the abnormal exit resulted in a coredump, this may also mean that your csh (C
shell) is broken. If so, you should change all of the csh-related variables in
config.sh: If you have tcsh, make the variables refer to it as if it were csh (e.g.
"full_csh='/usr/bin/tcsh'"); otherwise, make them all empty (except that "d_csh"
should be 'undef') so that Perl will think csh is missing. In either case, after
editing config.sh, run "./Configure -S" and rebuild Perl.
Glob not terminated
(F) The lexer saw a left angle bracket in a place where it was expecting a term, so
it's looking for the corresponding right angle bracket, and not finding it. Chances
are you left some needed parentheses out earlier in the line, and you really meant a
"less than".
gmtime(%f) failed
(W overflow) You called "gmtime" with a number that it could not handle: too large,
too small, or NaN. The returned value is "undef".
gmtime(%f) too large
(W overflow) You called "gmtime" with a number that was larger than it can reliably
handle and "gmtime" probably returned the wrong date. This warning is also triggered
with NaN (the special not-a-number value).
gmtime(%f) too small
(W overflow) You called "gmtime" with a number that was smaller than it can reliably
handle and "gmtime" probably returned the wrong date.
Got an error from DosAllocMem
(P) An error peculiar to OS/2. Most probably you're using an obsolete version of
Perl, and this should not happen anyway.
goto must have label
(F) Unlike with "next" or "last", you're not allowed to goto an unspecified
destination. See "goto" in perlfunc.
Goto undefined subroutine%s
(F) You tried to call a subroutine with "goto &sub" syntax, but the indicated
subroutine hasn't been defined, or if it was, it has since been undefined.
Group name must start with a non-digit word character in regex; marked by <-- HERE in
m/%s/
(F) Group names must follow the rules for perl identifiers, meaning they must start
with a non-digit word character. A common cause of this error is using (?&0) instead
of (?0). See perlre.
()-group starts with a count
(F) A ()-group started with a count. A count is supposed to follow something: a
template character or a ()-group. See "pack" in perlfunc.
%s had compilation errors.
(F) The final summary message when a "perl -c" fails.
Had to create %s unexpectedly
(S internal) A routine asked for a symbol from a symbol table that ought to have
existed already, but for some reason it didn't, and had to be created on an emergency
basis to prevent a core dump.
%s has too many errors
(F) The parser has given up trying to parse the program after 10 errors. Further
error messages would likely be uninformative.
Hexadecimal float: exponent overflow
(W overflow) The hexadecimal floating point has a larger exponent than the floating
point supports.
Hexadecimal float: exponent underflow
(W overflow) The hexadecimal floating point has a smaller exponent than the floating
point supports. With the IEEE 754 floating point, this may also mean that the
subnormals (formerly known as denormals) are being used, which may or may not be an
error.
Hexadecimal float: internal error (%s)
(F) Something went horribly bad in hexadecimal float handling.
Hexadecimal float: mantissa overflow
(W overflow) The hexadecimal floating point literal had more bits in the mantissa (the
part between the 0x and the exponent, also known as the fraction or the significand)
than the floating point supports.
Hexadecimal float: precision loss
(W overflow) The hexadecimal floating point had internally more digits than could be
output. This can be caused by unsupported long double formats, or by 64-bit integers
not being available (needed to retrieve the digits under some configurations).
Hexadecimal float: unsupported long double format
(F) You have configured Perl to use long doubles but the internals of the long double
format are unknown; therefore the hexadecimal float output is impossible.
Hexadecimal number > 0xffffffff non-portable
(W portable) The hexadecimal number you specified is larger than 2**32-1 (4294967295)
and therefore non-portable between systems. See perlport for more on portability
concerns.
Identifier too long
(F) Perl limits identifiers (names for variables, functions, etc.) to about 250
characters for simple names, and somewhat more for compound names (like $A::B).
You've exceeded Perl's limits. Future versions of Perl are likely to eliminate these
arbitrary limitations.
Ignoring zero length \N{} in character class in regex; marked by <-- HERE in m/%s/
(W regexp) Named Unicode character escapes ("\N{...}") may return a zero-length
sequence. When such an escape is used in a character class its behavior is not well
defined. Check that the correct escape has been used, and the correct charname
handler is in scope.
Illegal %s digit '%c' ignored
(W digit) Here %s is one of "binary", "octal", or "hex". You may have tried to use a
digit other than one that is legal for the given type, such as only 0 and 1 for
binary. For octals, this is raised only if the illegal character is an '8' or '9'.
For hex, 'A' - 'F' and 'a' - 'f' are legal. Interpretation of the number stopped just
before the offending digit or character.
Illegal binary digit '%c'
(F) You used a digit other than 0 or 1 in a binary number.
Illegal character after '_' in prototype for %s : %s
(W illegalproto) An illegal character was found in a prototype declaration. The '_'
in a prototype must be followed by a ';', indicating the rest of the parameters are
optional, or one of '@' or '%', since those two will accept 0 or more final
parameters.
Illegal character \%o (carriage return)
(F) Perl normally treats carriage returns in the program text as it would any other
whitespace, which means you should never see this error when Perl was built using
standard options. For some reason, your version of Perl appears to have been built
without this support. Talk to your Perl administrator.
Illegal character following sigil in a subroutine signature
(F) A parameter in a subroutine signature contained an unexpected character following
the "$", "@" or "%" sigil character. Normally the sigil should be followed by the
variable name or "=" etc. Perhaps you are trying use a prototype while in the scope
of "use feature 'signatures'"? For example:
sub foo ($$) {} # legal - a prototype
use feature 'signatures;
sub foo ($$) {} # illegal - was expecting a signature
sub foo ($x, $y)
:prototype($$) {} # legal
Illegal character in prototype for %s : %s
(W illegalproto) An illegal character was found in a prototype declaration. Legal
characters in prototypes are $, @, %, *, ;, [, ], &, \, and +. Perhaps you were
trying to write a subroutine signature but didn't enable that feature first ("use
feature 'signatures'"), so your signature was instead interpreted as a bad prototype.
Illegal declaration of anonymous subroutine
(F) When using the "sub" keyword to construct an anonymous subroutine, you must always
specify a block of code. See perlsub.
Illegal declaration of subroutine %s
(F) A subroutine was not declared correctly. See perlsub.
Illegal division by zero
(F) You tried to divide a number by 0. Either something was wrong in your logic, or
you need to put a conditional in to guard against meaningless input.
Illegal modulus zero
(F) You tried to divide a number by 0 to get the remainder. Most numbers don't take
to this kindly.
Illegal number of bits in vec
(F) The number of bits in vec() (the third argument) must be a power of two from 1 to
32 (or 64, if your platform supports that).
Illegal octal digit '%c'
(F) You used an 8 or 9 in an octal number.
Illegal operator following parameter in a subroutine signature
(F) A parameter in a subroutine signature, was followed by something other than "="
introducing a default, "," or ")".
use feature 'signatures';
sub foo ($=1) {} # legal
sub foo ($x = 1) {} # legal
sub foo ($x += 1) {} # illegal
sub foo ($x == 1) {} # illegal
Illegal pattern in regex; marked by <-- HERE in m/%s/
(F) You wrote something like
(?+foo)
The "+" is valid only when followed by digits, indicating a capturing group. See
"(?PARNO)".
Illegal suidscript
(F) The script run under suidperl was somehow illegal.
Illegal switch in PERL5OPT: -%c
(X) The PERL5OPT environment variable may only be used to set the following switches:
-[CDIMUdmtw].
Illegal user-defined property name
(F) You specified a Unicode-like property name in a regular expression pattern (using
"\p{}" or "\P{}") that Perl knows isn't an official Unicode property, and was likely
meant to be a user-defined property name, but it can't be one of those, as they must
begin with either "In" or "Is". Check the spelling. See also "Can't find Unicode
property definition "%s"".
Ill-formed CRTL environ value "%s"
(W internal) A warning peculiar to VMS. Perl tried to read the CRTL's internal
environ array, and encountered an element without the "=" delimiter used to separate
keys from values. The element is ignored.
Ill-formed message in prime_env_iter: |%s|
(W internal) A warning peculiar to VMS. Perl tried to read a logical name or CLI
symbol definition when preparing to iterate over %ENV, and didn't see the expected
delimiter between key and value, so the line was ignored.
(in cleanup) %s
(W misc) This prefix usually indicates that a DESTROY() method raised the indicated
exception. Since destructors are usually called by the system at arbitrary points
during execution, and often a vast number of times, the warning is issued only once
for any number of failures that would otherwise result in the same message being
repeated.
Failure of user callbacks dispatched using the "G_KEEPERR" flag could also result in
this warning. See "G_KEEPERR" in perlcall.
Implicit use of @_ in %s with signatured subroutine is experimental
(S experimental::args_array_with_signatures) An expression that implicitly involves
the @_ arguments array was found in a subroutine that uses a signature. This is
experimental because the interaction between the arguments array and parameter
handling via signatures is not guaranteed to remain stable in any future version of
Perl, and such code should be avoided.
Incomplete expression within '(?[ ])' in regex; marked by <-- HERE in m/%s/
(F) There was a syntax error within the "(?[ ])". This can happen if the expression
inside the construct was completely empty, or if there are too many or few operands
for the number of operators. Perl is not smart enough to give you a more precise
indication as to what is wrong.
Inconsistent hierarchy during C3 merge of class '%s': merging failed on parent '%s'
(F) The method resolution order (MRO) of the given class is not C3-consistent, and you
have enabled the C3 MRO for this class. See the C3 documentation in mro for more
information.
Indentation on line %d of here-doc doesn't match delimiter
(F) You have an indented here-document where one or more of its lines have whitespace
at the beginning that does not match the closing delimiter.
For example, line 2 below is wrong because it does not have at least 2 spaces, but
lines 1 and 3 are fine because they have at least 2:
if ($something) {
print <<~EOF;
Line 1
Line 2 not
Line 3
EOF
}
Note that tabs and spaces are compared strictly, meaning 1 tab will not match 8
spaces.
Infinite recursion in regex
(F) You used a pattern that references itself without consuming any input text. You
should check the pattern to ensure that recursive patterns either consume text or
fail.
Infinite recursion in user-defined property
(F) A user-defined property ("User-Defined Character Properties" in perlunicode) can
depend on the definitions of other user-defined properties. If the chain of
dependencies leads back to this property, infinite recursion would occur, were it not
for the check that raised this error.
Restructure your property definitions to avoid this.
Infinite recursion via empty pattern
(F) You tried to use the empty pattern inside of a regex code block, for instance
"/(?{ s!!! })/", which resulted in re-executing the same pattern, which is an infinite
loop which is broken by throwing an exception.
Initialization of state variables in list currently forbidden
(F) "state" only permits initializing a single variable, specified without
parentheses. So "state $x = 42" and "state @x = qw(a b c)" are allowed, but not
"state ($x) = 42" or "(state $x) = 42". To initialize more than one "state" variable,
initialize them one at a time.
%%s[%s] in scalar context better written as $%s[%s]
(W syntax) In scalar context, you've used an array index/value slice (indicated by %)
to select a single element of an array. Generally it's better to ask for a scalar
value (indicated by $). The difference is that $foo[&bar] always behaves like a
scalar, both in the value it returns and when evaluating its argument, while
%foo[&bar] provides a list context to its subscript, which can do weird things if
you're expecting only one subscript. When called in list context, it also returns the
index (what &bar returns) in addition to the value.
%%s{%s} in scalar context better written as $%s{%s}
(W syntax) In scalar context, you've used a hash key/value slice (indicated by %) to
select a single element of a hash. Generally it's better to ask for a scalar value
(indicated by $). The difference is that $foo{&bar} always behaves like a scalar,
both in the value it returns and when evaluating its argument, while @foo{&bar} and
provides a list context to its subscript, which can do weird things if you're
expecting only one subscript. When called in list context, it also returns the key in
addition to the value.
Insecure dependency in %s
(F) You tried to do something that the tainting mechanism didn't like. The tainting
mechanism is turned on when you're running setuid or setgid, or when you specify -T to
turn it on explicitly. The tainting mechanism labels all data that's derived directly
or indirectly from the user, who is considered to be unworthy of your trust. If any
such data is used in a "dangerous" operation, you get this error. See perlsec for
more information.
Insecure directory in %s
(F) You can't use system(), exec(), or a piped open in a setuid or setgid script if
$ENV{PATH} contains a directory that is writable by the world. Also, the PATH must
not contain any relative directory. See perlsec.
Insecure $ENV{%s} while running %s
(F) You can't use system(), exec(), or a piped open in a setuid or setgid script if
any of $ENV{PATH}, $ENV{IFS}, $ENV{CDPATH}, $ENV{ENV}, $ENV{BASH_ENV} or $ENV{TERM}
are derived from data supplied (or potentially supplied) by the user. The script must
set the path to a known value, using trustworthy data. See perlsec.
Insecure user-defined property %s
(F) Perl detected tainted data when trying to compile a regular expression that
contains a call to a user-defined character property function, i.e. "\p{IsFoo}" or
"\p{InFoo}". See "User-Defined Character Properties" in perlunicode and perlsec.
Integer overflow in format string for %s
(F) The indexes and widths specified in the format string of printf() or sprintf() are
too large. The numbers must not overflow the size of integers for your architecture.
Integer overflow in %s number
(S overflow) The hexadecimal, octal or binary number you have specified either as a
literal or as an argument to hex() or oct() is too big for your architecture, and has
been converted to a floating point number. On a 32-bit architecture the largest
hexadecimal, octal or binary number representable without overflow is 0xFFFFFFFF,
037777777777, or 0b11111111111111111111111111111111 respectively. Note that Perl
transparently promotes all numbers to a floating point representation
internally--subject to loss of precision errors in subsequent operations.
Integer overflow in srand
(S overflow) The number you have passed to srand is too big to fit in your
architecture's integer representation. The number has been replaced with the largest
integer supported (0xFFFFFFFF on 32-bit architectures). This means you may be getting
less randomness than you expect, because different random seeds above the maximum will
return the same sequence of random numbers.
Integer overflow in version
Integer overflow in version %d
(W overflow) Some portion of a version initialization is too large for the size of
integers for your architecture. This is not a warning because there is no rational
reason for a version to try and use an element larger than typically 2**32. This is
usually caused by trying to use some odd mathematical operation as a version, like
100/9.
Internal disaster in regex; marked by <-- HERE in m/%s/
(P) Something went badly wrong in the regular expression parser. The <-- HERE shows
whereabouts in the regular expression the problem was discovered.
Internal inconsistency in tracking vforks
(S) A warning peculiar to VMS. Perl keeps track of the number of times you've called
"fork" and "exec", to determine whether the current call to "exec" should affect the
current script or a subprocess (see "exec LIST" in perlvms). Somehow, this count has
become scrambled, so Perl is making a guess and treating this "exec" as a request to
terminate the Perl script and execute the specified command.
internal %<num>p might conflict with future printf extensions
(S internal) Perl's internal routine that handles "printf" and "sprintf" formatting
follows a slightly different set of rules when called from C or XS code.
Specifically, formats consisting of digits followed by "p" (e.g., "%7p") are reserved
for future use. If you see this message, then an XS module tried to call that routine
with one such reserved format.
Internal urp in regex; marked by <-- HERE in m/%s/
(P) Something went badly awry in the regular expression parser. The <-- HERE shows
whereabouts in the regular expression the problem was discovered.
%s (...) interpreted as function
(W syntax) You've run afoul of the rule that says that any list operator followed by
parentheses turns into a function, with all the list operators arguments found inside
the parentheses. See "Terms and List Operators (Leftward)" in perlop.
In '(?...)', the '(' and '?' must be adjacent in regex; marked by <-- HERE in m/%s/
(F) The two-character sequence "(?" in this context in a regular expression pattern
should be an indivisible token, with nothing intervening between the "(" and the "?",
but you separated them with whitespace.
In '(*...)', the '(' and '*' must be adjacent in regex; marked by <-- HERE in m/%s/
(F) The two-character sequence "(*" in this context in a regular expression pattern
should be an indivisible token, with nothing intervening between the "(" and the "*",
but you separated them. Fix the pattern and retry.
Invalid %s attribute: %s
(F) The indicated attribute for a subroutine or variable was not recognized by Perl or
by a user-supplied handler. See attributes.
Invalid %s attributes: %s
(F) The indicated attributes for a subroutine or variable were not recognized by Perl
or by a user-supplied handler. See attributes.
Invalid character in charnames alias definition; marked by <-- HERE in '%s
(F) You tried to create a custom alias for a character name, with the ":alias" option
to "use charnames" and the specified character in the indicated name isn't valid. See
"CUSTOM ALIASES" in charnames.
Invalid \0 character in %s for %s: %s\0%s
(W syscalls) Embedded \0 characters in pathnames or other system call arguments
produce a warning as of 5.20. The parts after the \0 were formerly ignored by system
calls.
Invalid character in \N{...}; marked by <-- HERE in \N{%s}
(F) Only certain characters are valid for character names. The indicated one isn't.
See "CUSTOM ALIASES" in charnames.
Invalid conversion in %s: "%s"
(W printf) Perl does not understand the given format conversion. See "sprintf" in
perlfunc.
Invalid escape in the specified encoding in regex; marked by <-- HERE in m/%s/
(W regexp)(F) The numeric escape (for example "\xHH") of value < 256 didn't correspond
to a single character through the conversion from the encoding specified by the
encoding pragma. The escape was replaced with REPLACEMENT CHARACTER (U+FFFD) instead,
except within "(?[ ])", where it is a fatal error. The <-- HERE shows whereabouts
in the regular expression the escape was discovered.
Invalid hexadecimal number in \N{U+...}
Invalid hexadecimal number in \N{U+...} in regex; marked by <-- HERE in m/%s/
(F) The character constant represented by "..." is not a valid hexadecimal number.
Either it is empty, or you tried to use a character other than 0 - 9 or A - F, a - f
in a hexadecimal number.
Invalid module name %s with -%c option: contains single ':'
(F) The module argument to perl's -m and -M command-line options cannot contain single
colons in the module name, but only in the arguments after "=". In other words,
-MFoo::Bar=:baz is ok, but -MFoo:Bar=baz is not.
Invalid mro name: '%s'
(F) You tried to "mro::set_mro("classname", "foo")" or "use mro 'foo'", where "foo" is
not a valid method resolution order (MRO). Currently, the only valid ones supported
are "dfs" and "c3", unless you have loaded a module that is a MRO plugin. See mro and
perlmroapi.
Invalid negative number (%s) in chr
(W utf8) You passed a negative number to "chr". Negative numbers are not valid
character numbers, so it returns the Unicode replacement character (U+FFFD).
Invalid number '%s' for -C option.
(F) You supplied a number to the -C option that either has extra leading zeroes or
overflows perl's unsigned integer representation.
invalid option -D%c, use -D'' to see choices
(S debugging) Perl was called with invalid debugger flags. Call perl with the -D
option with no flags to see the list of acceptable values. See also "-Dletters" in
perlrun.
Invalid quantifier in {,} in regex; marked by <-- HERE in m/%s/
(F) The pattern looks like a {min,max} quantifier, but the min or max could not be
parsed as a valid number - either it has leading zeroes, or it represents too big a
number to cope with. The <-- HERE shows where in the regular expression the problem
was discovered. See perlre.
Invalid [] range "%s" in regex; marked by <-- HERE in m/%s/
(F) The range specified in a character class had a minimum character greater than the
maximum character. One possibility is that you forgot the "{}" from your ending
"\x{}" - "\x" without the curly braces can go only up to "ff". The <-- HERE shows
whereabouts in the regular expression the problem was discovered. See perlre.
Invalid range "%s" in transliteration operator
(F) The range specified in the tr/// or y/// operator had a minimum character greater
than the maximum character. See perlop.
Invalid reference to group in regex; marked by <-- HERE in m/%s/
(F) The capture group you specified can't possibly exist because the number you used
is not within the legal range of possible values for this machine.
Invalid separator character %s in attribute list
(F) Something other than a colon or whitespace was seen between the elements of an
attribute list. If the previous attribute had a parenthesised parameter list, perhaps
that list was terminated too soon. See attributes.
Invalid separator character %s in PerlIO layer specification %s
(W layer) When pushing layers onto the Perl I/O system, something other than a colon
or whitespace was seen between the elements of a layer list. If the previous
attribute had a parenthesised parameter list, perhaps that list was terminated too
soon.
Invalid strict version format (%s)
(F) A version number did not meet the "strict" criteria for versions. A "strict"
version number is a positive decimal number (integer or decimal-fraction) without
exponentiation or else a dotted-decimal v-string with a leading 'v' character and at
least three components. The parenthesized text indicates which criteria were not met.
See the version module for more details on allowed version formats.
Invalid type '%s' in %s
(F) The given character is not a valid pack or unpack type. See "pack" in perlfunc.
(W) The given character is not a valid pack or unpack type but used to be silently
ignored.
Invalid version bundle "%s"
(F) A version number that is used to specify an import bundle during a "use builtin
..." statement must be formatted as ":MAJOR.MINOR" with an optional third component,
which is ignored. Each component must be a number of 1 to 3 digits. No other
characters are permitted. The value that was specified does not conform to these
rules.
Invalid version format (%s)
(F) A version number did not meet the "lax" criteria for versions. A "lax" version
number is a positive decimal number (integer or decimal-fraction) without
exponentiation or else a dotted-decimal v-string. If the v-string has fewer than
three components, it must have a leading 'v' character. Otherwise, the leading 'v' is
optional. Both decimal and dotted-decimal versions may have a trailing "alpha"
component separated by an underscore character after a fractional or dotted-decimal
component. The parenthesized text indicates which criteria were not met. See the
version module for more details on allowed version formats.
Invalid version object
(F) The internal structure of the version object was invalid. Perhaps the internals
were modified directly in some way or an arbitrary reference was blessed into the
"version" class.
In '(*VERB...)', the '(' and '*' must be adjacent in regex; marked by <-- HERE in m/%s/
Inverting a character class which contains a multi-character sequence is illegal in regex;
marked by <-- HERE in m/%s/
(F) You wrote something like
qr/\P{name=KATAKANA LETTER AINU P}/
qr/[^\p{name=KATAKANA LETTER AINU P}]/
This name actually evaluates to a sequence of two Katakana characters, not just a
single one, and it is illegal to try to take the complement of a sequence.
(Mathematically it would mean any sequence of characters from 0 to infinity in length
that weren't these two in a row, and that is likely not of any real use.)
(F) The two-character sequence "(*" in this context in a regular expression pattern
should be an indivisible token, with nothing intervening between the "(" and the "*",
but you separated them.
ioctl is not implemented
(F) Your machine apparently doesn't implement ioctl(), which is pretty strange for a
machine that supports C.
ioctl() on unopened %s
(W unopened) You tried ioctl() on a filehandle that was never opened. Check your
control flow and number of arguments.
IO layers (like '%s') unavailable
(F) Your Perl has not been configured to have PerlIO, and therefore you cannot use IO
layers. To have PerlIO, Perl must be configured with 'useperlio'.
IO::Socket::atmark not implemented on this architecture
(F) Your machine doesn't implement the sockatmark() functionality, neither as a system
call nor an ioctl call (SIOCATMARK).
'%s' is an unknown bound type in regex; marked by <-- HERE in m/%s/
(F) You used "\b{...}" or "\B{...}" and the "..." is not known to Perl. The current
valid ones are given in "\b{}, \b, \B{}, \B" in perlrebackslash.
%s() isn't allowed on :utf8 handles
(F) The sysread(), recv(), syswrite() and send() operators are not allowed on handles
that have the ":utf8" layer, either explicitly, or implicitly, eg., with the
:encoding(UTF-16LE) layer.
Previously sysread() and recv() currently use only the ":utf8" flag for the stream,
ignoring the actual layers. Since sysread() and recv() did no UTF-8 validation they
can end up creating invalidly encoded scalars.
Similarly, syswrite() and send() used only the ":utf8" flag, otherwise ignoring any
layers. If the flag is set, both wrote the value UTF-8 encoded, even if the layer is
some different encoding, such as the example above.
Ideally, all of these operators would completely ignore the ":utf8" state, working
only with bytes, but this would result in silently breaking existing code.
"%s" is more clearly written simply as "%s" in regex; marked by <-- HERE in m/%s/
(W regexp) (only under "use re 'strict'" or within "(?[...])")
You specified a character that has the given plainer way of writing it, and which is
also portable to platforms running with different character sets.
$* is no longer supported as of Perl 5.30
(F) The special variable $*, deprecated in older perls, was removed in 5.10.0, is no
longer supported and is a fatal error as of Perl 5.30. In previous versions of perl
the use of $* enabled or disabled multi-line matching within a string.
Instead of using $* you should use the "/m" (and maybe "/s") regexp modifiers. You
can enable "/m" for a lexical scope (even a whole file) with "use re '/m'". (In older
versions: when $* was set to a true value then all regular expressions behaved as if
they were written using "/m".)
Use of this variable will be a fatal error in Perl 5.30.
$# is no longer supported as of Perl 5.30
(F) The special variable $#, deprecated in older perls, was removed as of 5.10.0, is
no longer supported and is a fatal error as of Perl 5.30. You should use the
printf/sprintf functions instead.
'%s' is not a code reference
(W overload) The second (fourth, sixth, ...) argument of overload::constant needs to
be a code reference. Either an anonymous subroutine, or a reference to a subroutine.
'%s' is not an overloadable type
(W overload) You tried to overload a constant type the overload package is unaware of.
'%s' is not recognised as a builtin function
(F) An attempt was made to "use" the builtin pragma module to create a lexical alias
for an unknown function name.
-i used with no filenames on the command line, reading from STDIN
(S inplace) The "-i" option was passed on the command line, indicating that the script
is intended to edit files in place, but no files were given. This is usually a
mistake, since editing STDIN in place doesn't make sense, and can be confusing because
it can make perl look like it is hanging when it is really just trying to read from
STDIN. You should either pass a filename to edit, or remove "-i" from the command
line. See perlrun for more details.
Junk on end of regexp in regex m/%s/
(P) The regular expression parser is confused.
\K not permitted in lookahead/lookbehind in regex; marked by <-- HERE in m/%s/
(F) Your regular expression used "\K" in a lookahead or lookbehind assertion, which
currently isn't permitted.
This may change in the future, see Support \K in lookarounds
<https://github.com/Perl/perl5/issues/18134>.
Label not found for "last %s"
(F) You named a loop to break out of, but you're not currently in a loop of that name,
not even if you count where you were called from. See "last" in perlfunc.
Label not found for "next %s"
(F) You named a loop to continue, but you're not currently in a loop of that name, not
even if you count where you were called from. See "last" in perlfunc.
Label not found for "redo %s"
(F) You named a loop to restart, but you're not currently in a loop of that name, not
even if you count where you were called from. See "last" in perlfunc.
leaving effective %s failed
(F) While under the "use filetest" pragma, switching the real and effective uids or
gids failed.
length/code after end of string in unpack
(F) While unpacking, the string buffer was already used up when an unpack length/code
combination tried to obtain more data. This results in an undefined value for the
length. See "pack" in perlfunc.
length() used on %s (did you mean "scalar(%s)"?)
(W syntax) You used length() on either an array or a hash when you probably wanted a
count of the items.
Array size can be obtained by doing:
scalar(@array);
The number of items in a hash can be obtained by doing:
scalar(keys %hash);
Lexing code attempted to stuff non-Latin-1 character into Latin-1 input
(F) An extension is attempting to insert text into the current parse (using
lex_stuff_pvn or similar), but tried to insert a character that couldn't be part of
the current input. This is an inherent pitfall of the stuffing mechanism, and one of
the reasons to avoid it. Where it is necessary to stuff, stuffing only plain ASCII is
recommended.
Lexing code internal error (%s)
(F) Lexing code supplied by an extension violated the lexer's API in a detectable way.
listen() on closed socket %s
(W closed) You tried to do a listen on a closed socket. Did you forget to check the
return value of your socket() call? See "listen" in perlfunc.
List form of piped open not implemented
(F) On some platforms, notably Windows, the three-or-more-arguments form of "open"
does not support pipes, such as "open($pipe, '|-', @args)". Use the two-argument
"open($pipe, '|prog arg1 arg2...')" form instead.
Literal vertical space in [] is illegal except under /x in regex; marked by <-- HERE in
m/%s/
(F) (only under "use re 'strict'" or within "(?[...])")
Likely you forgot the "/x" modifier or there was a typo in the pattern. For example,
did you really mean to match a form-feed? If so, all the ASCII vertical space control
characters are representable by escape sequences which won't present such a jarring
appearance as your pattern does when displayed.
\r carriage return
\f form feed
\n line feed
\cK vertical tab
%s: loadable library and perl binaries are mismatched (got %s handshake key %p, needed %p)
(P) A dynamic loading library ".so" or ".dll" was being loaded into the process that
was built against a different build of perl than the said library was compiled
against. Reinstalling the XS module will likely fix this error.
Locale '%s' contains (at least) the following characters which have unexpected meanings:
%s The Perl program will use the expected meanings
(W locale) You are using the named UTF-8 locale. UTF-8 locales are expected to have
very particular behavior, which most do. This message arises when perl found some
departures from the expectations, and is notifying you that the expected behavior
overrides these differences. In some cases the differences are caused by the locale
definition being defective, but the most common causes of this warning are when there
are ambiguities and conflicts in following the Standard, and the locale has chosen an
approach that differs from Perl's.
One of these is because that, contrary to the claims, Unicode is not completely locale
insensitive. Turkish and some related languages have two types of "I" characters.
One is dotted in both upper- and lowercase, and the other is dotless in both cases.
Unicode allows a locale to use either the Turkish rules, or the rules used in all
other instances, where there is only one type of "I", which is dotless in the
uppercase, and dotted in the lower. The perl core does not (yet) handle the Turkish
case, and this message warns you of that. Instead, the Unicode::Casing module allows
you to mostly implement the Turkish casing rules.
The other common cause is for the characters
$ + < = > ^ ` | ~
These are problematic. The C standard says that these should be considered
punctuation in the C locale (and the POSIX standard defers to the C standard), and
Unicode is generally considered a superset of the C locale. But Unicode has added an
extra category, "Symbol", and classifies these particular characters as being symbols.
Most UTF-8 locales have them treated as punctuation, so that ispunct(3) returns non-
zero for them. But a few locales have it return 0. Perl takes the first approach,
not using ispunct() at all (see Note [5] in perlrecharclass), and this message is
raised to notify you that you are getting Perl's approach, not the locale's.
Locale '%s' is unsupported, and may crash the interpreter
(S locale) The named locale is not supported by Perl, and using it leads to undefined
behavior, including potentially crashing the computer.
Currently the only locales that generate this severe warning are non-UTF-8 ones which
have characters that require more than one byte to represent (common in older East
Asian language locales). See perllocale.
Locale '%s' may not work well.%s
(W locale) You are using the named locale, which is a non-UTF-8 one, and which perl
has determined is not fully compatible with what it can handle. The second %s gives a
reason.
By far the most common reason is that the locale has characters in it that are
represented by more than one byte. The only such locales that Perl can handle are the
UTF-8 locales. Most likely the specified locale is a non-UTF-8 one for an East Asian
language such as Chinese or Japanese. If the locale is a superset of ASCII, the ASCII
portion of it may work in Perl.
Some essentially obsolete locales that aren't supersets of ASCII, mainly those in ISO
646 or other 7-bit locales, such as ASMO 449, can also have problems, depending on
what portions of the ASCII character set get changed by the locale and are also used
by the program. The warning message lists the determinable conflicting characters.
Note that not all incompatibilities are found.
If this happens to you, there's not much you can do except switch to use a different
locale or use Encode to translate from the locale into UTF-8; if that's impracticable,
you have been warned that some things may break.
This message is output once each time a bad locale is switched into within the scope
of "use locale", or on the first possibly-affected operation if the "use locale"
inherits a bad one. It is not raised for any operations from the POSIX module.
localtime(%f) failed
(W overflow) You called "localtime" with a number that it could not handle: too large,
too small, or NaN. The returned value is "undef".
localtime(%f) too large
(W overflow) You called "localtime" with a number that was larger than it can reliably
handle and "localtime" probably returned the wrong date. This warning is also
triggered with NaN (the special not-a-number value).
localtime(%f) too small
(W overflow) You called "localtime" with a number that was smaller than it can
reliably handle and "localtime" probably returned the wrong date.
Lookbehind longer than %d not implemented in regex m/%s/
(F) There is currently a limit on the length of string which lookbehind can handle.
This restriction may be eased in a future release.
Lost precision when %s %f by 1
(W imprecision) You attempted to increment or decrement a value by one, but the result
is too large for the underlying floating point representation to store accurately.
Hence, the target of "++" or "--" is increased or decreased by quite different value
than one, such as zero (i.e. the target is unchanged) or two, due to rounding. Perl
issues this warning because it has already switched from integers to floating point
when values are too large for integers, and now even floating point is insufficient.
You may wish to switch to using Math::BigInt explicitly.
lstat() on filehandle%s
(W io) You tried to do an lstat on a filehandle. What did you mean by that? lstat()
makes sense only on filenames. (Perl did a fstat() instead on the filehandle.)
lvalue attribute %s already-defined subroutine
(W misc) Although attributes.pm allows this, turning the lvalue attribute on or off on
a Perl subroutine that is already defined does not always work properly. It may or
may not do what you want, depending on what code is inside the subroutine, with exact
details subject to change between Perl versions. Only do this if you really know what
you are doing.
lvalue attribute ignored after the subroutine has been defined
(W misc) Using the ":lvalue" declarative syntax to make a Perl subroutine an lvalue
subroutine after it has been defined is not permitted. To make the subroutine an
lvalue subroutine, add the lvalue attribute to the definition, or put the "sub foo
:lvalue;" declaration before the definition.
See also attributes.pm.
Magical list constants are not supported
(F) You assigned a magical array to a stash element, and then tried to use the
subroutine from the same slot. You are asking Perl to do something it cannot do,
details subject to change between Perl versions.
Malformed integer in [] in pack
(F) Between the brackets enclosing a numeric repeat count only digits are permitted.
See "pack" in perlfunc.
Malformed integer in [] in unpack
(F) Between the brackets enclosing a numeric repeat count only digits are permitted.
See "pack" in perlfunc.
Malformed PERLLIB_PREFIX
(F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form
prefix1;prefix2
or
prefix1 prefix2
with nonempty prefix1 and prefix2. If "prefix1" is indeed a prefix of a builtin
library search path, prefix2 is substituted. The error may appear if components are
not found, or are too long. See "PERLLIB_PREFIX" in perlos2.
Malformed prototype for %s: %s
(F) You tried to use a function with a malformed prototype. The syntax of function
prototypes is given a brief compile-time check for obvious errors like invalid
characters. A more rigorous check is run when the function is called. Perhaps the
function's author was trying to write a subroutine signature but didn't enable that
feature first ("use feature 'signatures'"), so the signature was instead interpreted
as a bad prototype.
Malformed UTF-8 character%s
(S utf8)(F) Perl detected a string that should be UTF-8, but didn't comply with UTF-8
encoding rules, or represents a code point whose ordinal integer value doesn't fit
into the word size of the current platform (overflows). Details as to the exact
malformation are given in the variable, %s, part of the message.
One possible cause is that you set the UTF8 flag yourself for data that you thought to
be in UTF-8 but it wasn't (it was for example legacy 8-bit data). To guard against
this, you can use "Encode::decode('UTF-8', ...)".
If you use the :encoding(UTF-8) PerlIO layer for input, invalid byte sequences are
handled gracefully, but if you use ":utf8", the flag is set without validating the
data, possibly resulting in this error message.
See also "Handling Malformed Data" in Encode.
Malformed UTF-8 returned by \N{%s} immediately after '%s'
(F) The charnames handler returned malformed UTF-8.
Malformed UTF-8 string in "%s"
(F) This message indicates a bug either in the Perl core or in XS code. Such code was
trying to find out if a character, allegedly stored internally encoded as UTF-8, was
of a given type, such as being punctuation or a digit. But the character was not
encoded in legal UTF-8. The %s is replaced by a string that can be used by
knowledgeable people to determine what the type being checked against was.
Passing malformed strings was deprecated in Perl 5.18, and became fatal in Perl 5.26.
Malformed UTF-8 string in '%c' format in unpack
(F) You tried to unpack something that didn't comply with UTF-8 encoding rules and
perl was unable to guess how to make more progress.
Malformed UTF-8 string in pack
(F) You tried to pack something that didn't comply with UTF-8 encoding rules and perl
was unable to guess how to make more progress.
Malformed UTF-8 string in unpack
(F) You tried to unpack something that didn't comply with UTF-8 encoding rules and
perl was unable to guess how to make more progress.
Malformed UTF-16 surrogate
(F) Perl thought it was reading UTF-16 encoded character data but while doing it Perl
met a malformed Unicode surrogate.
Mandatory parameter follows optional parameter
(F) In a subroutine signature, you wrote something like "$x = undef, $y", making an
earlier parameter optional and a later one mandatory. Parameters are filled from left
to right, so it's impossible for the caller to omit an earlier one and pass a later
one. If you want to act as if the parameters are filled from right to left, declare
the rightmost optional and then shuffle the parameters around in the subroutine's
body.
Matched non-Unicode code point 0x%X against Unicode property; may not be portable
(S non_unicode) Perl allows strings to contain a superset of Unicode code points; each
code point may be as large as what is storable in a signed integer on your system, but
these may not be accepted by other languages/systems. This message occurs when you
matched a string containing such a code point against a regular expression pattern,
and the code point was matched against a Unicode property, "\p{...}" or "\P{...}".
Unicode properties are only defined on Unicode code points, so the result of this
match is undefined by Unicode, but Perl (starting in v5.20) treats non-Unicode code
points as if they were typical unassigned Unicode ones, and matched this one
accordingly. Whether a given property matches these code points or not is specified
in "Properties accessible through \p{} and \P{}" in perluniprops.
This message is suppressed (unless it has been made fatal) if it is immaterial to the
results of the match if the code point is Unicode or not. For example, the property
"\p{ASCII_Hex_Digit}" only can match the 22 characters "[0-9A-Fa-f]", so obviously all
other code points, Unicode or not, won't match it. (And "\P{ASCII_Hex_Digit}" will
match every code point except these 22.)
Getting this message indicates that the outcome of the match arguably should have been
the opposite of what actually happened. If you think that is the case, you may wish
to make the "non_unicode" warnings category fatal; if you agree with Perl's decision,
you may wish to turn off this category.
See "Beyond Unicode code points" in perlunicode for more information.
%s matches null string many times in regex; marked by <-- HERE in m/%s/
(W regexp) The pattern you've specified would be an infinite loop if the regular
expression engine didn't specifically check for that. The <-- HERE shows whereabouts
in the regular expression the problem was discovered. See perlre.
Maximal count of pending signals (%u) exceeded
(F) Perl aborted due to too high a number of signals pending. This usually indicates
that your operating system tried to deliver signals too fast (with a very high
priority), starving the perl process from resources it would need to reach a point
where it can process signals safely. (See "Deferred Signals (Safe Signals)" in
perlipc.)
"%s" may clash with future reserved word
(W) This warning may be due to running a perl5 script through a perl4 interpreter,
especially if the word that is being warned about is "use" or "my".
'%' may not be used in pack
(F) You can't pack a string by supplying a checksum, because the checksumming process
loses information, and you can't go the other way. See "unpack" in perlfunc.
Method for operation %s not found in package %s during blessing
(F) An attempt was made to specify an entry in an overloading table that doesn't
resolve to a valid subroutine. See overload.
method is experimental
(S experimental::class) This warning is emitted if you use the "method" keyword of
"use feature 'class'". This keyword is currently experimental and its behaviour may
change in future releases of Perl.
Method %s not permitted
See "500 Server error".
Method %s redefined
(W redefine) You redefined a method. To suppress this warning, say
{
no warnings 'redefine';
*name = method { ... };
}
Might be a runaway multi-line %s string starting on line %d
(S) An advisory indicating that the previous error may have been caused by a missing
delimiter on a string or pattern, because it eventually ended earlier on the current
line.
Mismatched brackets in template
(F) A pack template could not be parsed because pairs of "[...]" or "(...)" could not
be matched up. See "pack" in perlfunc.
Misplaced _ in number
(W syntax) An underscore (underbar) in a numeric constant did not separate two digits.
Missing argument for %n in %s
(F) A %n was used in a format string with no corresponding argument for perl to write
the current string length to.
Missing argument in %s
(W missing) You called a function with fewer arguments than other arguments you
supplied indicated would be needed.
Currently only emitted when a printf-type format required more arguments than were
supplied, but might be used in the future for other cases where we can statically
determine that arguments to functions are missing, e.g. for the "pack" in perlfunc
function.
Missing argument to -%c
(F) The argument to the indicated command line switch must follow immediately after
the switch, without intervening spaces.
Missing braces on \N{}
Missing braces on \N{} in regex; marked by <-- HERE in m/%s/
(F) Wrong syntax of character name literal "\N{charname}" within double-quotish
context. This can also happen when there is a space (or comment) between the "\N" and
the "{" in a regex with the "/x" modifier. This modifier does not change the
requirement that the brace immediately follow the "\N".
Missing braces on \o{}
(F) A "\o" must be followed immediately by a "{" in double-quotish context.
Missing comma after first argument to %s function
(F) While certain functions allow you to specify a filehandle or an "indirect object"
before the argument list, this ain't one of them.
Missing comma after first argument to return
(F) While certain operators allow you to specify a filehandle or an "indirect object"
before the argument list, "return" isn't one of them.
Missing command in piped open
(W pipe) You used the "open(FH, "| command")" or "open(FH, "command |")" construction,
but the command was missing or blank.
Missing control char name in \c
(F) A double-quoted string ended with "\c", without the required control character
name.
Missing ']' in prototype for %s : %s
(W illegalproto) A grouping was started with "[" but never closed with "]".
Missing name in "%s sub"
(F) The syntax for lexically scoped subroutines requires that they have a name with
which they can be found.
Missing $ on loop variable
(F) Apparently you've been programming in csh too much. Variables are always
mentioned with the $ in Perl, unlike in the shells, where it can vary from one line to
the next.
(Missing operator before %s?)
(S syntax) This is an educated guess made in conjunction with the message "%s found
where operator expected". Often the missing operator is a comma.
Missing or undefined argument to %s
(F) You tried to call "require" or "do" with no argument or with an undefined value as
an argument. Require expects either a package name or a file-specification as an
argument; do expects a filename. See "require EXPR" in perlfunc and "do EXPR" in
perlfunc.
Missing or undefined argument to %s via %{^HOOK}{require__before}
(F) A "%{^HOOK}{require__before}" hook rewrote the name of the file being compiled
with "require" or "do" with an empty string an undefined value which is forbidden.
See "%{^HOOK}" in perlvar and "require EXPR" in perlfunc.
Missing right brace on \%c{} in regex; marked by <-- HERE in m/%s/
(F) Missing right brace in "\x{...}", "\p{...}", "\P{...}", or "\N{...}".
Missing right brace on \N{}
Missing right brace on \N{} or unescaped left brace after \N
(F) "\N" has two meanings.
The traditional one has it followed by a name enclosed in braces, meaning the
character (or sequence of characters) given by that name. Thus "\N{ASTERISK}" is
another way of writing "*", valid in both double-quoted strings and regular expression
patterns. In patterns, it doesn't have the meaning an unescaped "*" does.
Starting in Perl 5.12.0, "\N" also can have an additional meaning (only) in patterns,
namely to match a non-newline character. (This is short for "[^\n]", and like "." but
is not affected by the "/s" regex modifier.)
This can lead to some ambiguities. When "\N" is not followed immediately by a left
brace, Perl assumes the "[^\n]" meaning. Also, if the braces form a valid quantifier
such as "\N{3}" or "\N{5,}", Perl assumes that this means to match the given quantity
of non-newlines (in these examples, 3; and 5 or more, respectively). In all other
case, where there is a "\N{" and a matching "}", Perl assumes that a character name is
desired.
However, if there is no matching "}", Perl doesn't know if it was mistakenly omitted,
or if "[^\n]{" was desired, and raises this error. If you meant the former, add the
right brace; if you meant the latter, escape the brace with a backslash, like so:
"\N\{"
Missing right curly or square bracket
(F) The lexer counted more opening curly or square brackets than closing ones. As a
general rule, you'll find it's missing near the place you were last editing.
(Missing semicolon on previous line?)
(S syntax) This is an educated guess made in conjunction with the message "%s found
where operator expected". Don't automatically put a semicolon on the previous line
just because you saw this message.
Modification of a read-only value attempted
(F) You tried, directly or indirectly, to change the value of a constant. You didn't,
of course, try "2 = 1", because the compiler catches that. But an easy way to do the
same thing is:
sub mod { $_[0] = 1 }
mod(2);
Another way is to assign to a substr() that's off the end of the string.
Yet another way is to assign to a "foreach" loop VAR when VAR is aliased to a constant
in the look LIST:
$x = 1;
foreach my $n ($x, 2) {
$n *= 2; # modifies the $x, but fails on attempt to
} # modify the 2
PerlIO::scalar will also produce this message as a warning if you attempt to open a
read-only scalar for writing.
Modification of non-creatable array value attempted, %s
(F) You tried to make an array value spring into existence, and the subscript was
probably negative, even counting from end of the array backwards.
Modification of non-creatable hash value attempted, %s
(P) You tried to make a hash value spring into existence, and it couldn't be created
for some peculiar reason.
Module name must be constant
(F) Only a bare module name is allowed as the first argument to a "use".
Module name required with -%c option
(F) The "-M" or "-m" options say that Perl should load some module, but you omitted
the name of the module. Consult perlrun for full details about "-M" and "-m".
More than one argument to '%s' open
(F) The "open" function has been asked to open multiple files. This can happen if you
are trying to open a pipe to a command that takes a list of arguments, but have
forgotten to specify a piped open mode. See "open" in perlfunc for details.
mprotect for COW string %p %u failed with %d
(S) You compiled perl with -DPERL_DEBUG_READONLY_COW (see "Copy on Write" in
perlguts), but a shared string buffer could not be made read-only.
mprotect for %p %u failed with %d
(S) You compiled perl with -DPERL_DEBUG_READONLY_OPS (see perlhacktips), but an op
tree could not be made read-only.
mprotect RW for COW string %p %u failed with %d
(S) You compiled perl with -DPERL_DEBUG_READONLY_COW (see "Copy on Write" in
perlguts), but a read-only shared string buffer could not be made mutable.
mprotect RW for %p %u failed with %d
(S) You compiled perl with -DPERL_DEBUG_READONLY_OPS (see perlhacktips), but a read-
only op tree could not be made mutable before freeing the ops.
msg%s not implemented
(F) You don't have System V message IPC on your system.
Multidimensional hash lookup is disabled
(F) You supplied a list of subscripts to a hash lookup under "no feature
"multidimensional";", eg:
$z = $foo{$x, $y};
which by default acts like:
$z = $foo{join($;, $x, $y)};
Multidimensional syntax %s not supported
(W syntax) Multidimensional arrays aren't written like $foo[1,2,3]. They're written
like "$foo[1][2][3]", as in C.
Multiple slurpy parameters not allowed
(F) In subroutine signatures, a slurpy parameter ("@" or "%") must be the last
parameter, and there must not be more than one of them; for example:
sub foo ($x, @y) {} # legal
sub foo ($x, @y, %) {} # invalid
'/' must follow a numeric type in unpack
(F) You had an unpack template that contained a '/', but this did not follow some
unpack specification producing a numeric value. See "pack" in perlfunc.
%s must not be a named sequence in transliteration operator
(F) Transliteration ("tr///" and "y///") transliterates individual characters. But a
named sequence by definition is more than an individual character, and hence doing
this operation on it doesn't make sense.
"my sub" not yet implemented
(F) Lexically scoped subroutines are not yet implemented. Don't try that yet.
"my" subroutine %s can't be in a package
(F) Lexically scoped subroutines aren't in a package, so it doesn't make sense to try
to declare one with a package qualifier on the front.
"my %s" used in sort comparison
(W syntax) The package variables $a and $b are used for sort comparisons. You used $a
or $b in as an operand to the "<=>" or "cmp" operator inside a sort comparison block,
and the variable had earlier been declared as a lexical variable. Either qualify the
sort variable with the package name, or rename the lexical variable.
"my" variable %s can't be in a package
(F) Lexically scoped variables aren't in a package, so it doesn't make sense to try to
declare one with a package qualifier on the front. Use local() if you want to
localize a package variable.
Name "%s::%s" used only once: possible typo
(W once) Typographical errors often show up as unique variable names. If you had a
good reason for having a unique name, then just mention it again somehow to suppress
the message. The "our" declaration is also provided for this purpose.
NOTE: This warning detects package symbols that have been used only once. This means
lexical variables will never trigger this warning. It also means that all of the
package variables $c, @c, %c, as well as *c, &c, sub c{}, c(), and c (the filehandle
or format) are considered the same; if a program uses $c only once but also uses any
of the others it will not trigger this warning. Symbols beginning with an underscore
and symbols using special identifiers (q.v. perldata) are exempt from this warning.
Need exactly 3 octal digits in regex; marked by <-- HERE in m/%s/
(F) Within "(?[ ])", all constants interpreted as octal need to be exactly 3 digits
long. This helps catch some ambiguities. If your constant is too short, add leading
zeros, like
(?[ [ \078 ] ]) # Syntax error!
(?[ [ \0078 ] ]) # Works
(?[ [ \007 8 ] ]) # Clearer
The maximum number this construct can express is "\777". If you need a larger one,
you need to use \o{} instead. If you meant two separate things, you need to separate
them:
(?[ [ \7776 ] ]) # Syntax error!
(?[ [ \o{7776} ] ]) # One meaning
(?[ [ \777 6 ] ]) # Another meaning
(?[ [ \777 \006 ] ]) # Still another
Negative '/' count in unpack
(F) The length count obtained from a length/code unpack operation was negative. See
"pack" in perlfunc.
Negative length
(F) You tried to do a read/write/send/recv operation with a buffer length that is less
than 0. This is difficult to imagine.
Negative offset to vec in lvalue context
(F) When "vec" is called in an lvalue context, the second argument must be greater
than or equal to zero.
Negative repeat count does nothing
(W numeric) You tried to execute the "x" repetition operator fewer than 0 times, which
doesn't make sense.
Nested quantifiers in regex; marked by <-- HERE in m/%s/
(F) You can't quantify a quantifier without intervening parentheses. So things like
** or +* or ?* are illegal. The <-- HERE shows whereabouts in the regular expression
the problem was discovered.
Note that the minimal matching quantifiers, "*?", "+?", and "??" appear to be nested
quantifiers, but aren't. See perlre.
%s never introduced
(S internal) The symbol in question was declared but somehow went out of scope before
it could possibly have been used.
next::method/next::can/maybe::next::method cannot find enclosing method
(F) "next::method" needs to be called within the context of a real method in a real
package, and it could not find such a context. See mro.
\N in a character class must be a named character: \N{...} in regex; marked by <-- HERE in
m/%s/
(F) The new (as of Perl 5.12) meaning of "\N" as "[^\n]" is not valid in a bracketed
character class, for the same reason that "." in a character class loses its
specialness: it matches almost everything, which is probably not what you want.
\N{} here is restricted to one character in regex; marked by <-- HERE in m/%s/
(F) Named Unicode character escapes ("\N{...}") may return a multi-character sequence.
Even though a character class is supposed to match just one character of input, perl
will match the whole thing correctly, except under certain conditions. These
currently are
When the class is inverted ("[^...]")
The mathematically logical behavior for what matches when inverting is very
different from what people expect, so we have decided to forbid it.
The escape is the beginning or final end point of a range
Similarly unclear is what should be generated when the "\N{...}" is used as one of
the end points of the range, such as in
[\x{41}-\N{ARABIC SEQUENCE YEH WITH HAMZA ABOVE WITH AE}]
What is meant here is unclear, as the "\N{...}" escape is a sequence of code
points, so this is made an error.
In a regex set
The syntax "(?[ ])" in a regular expression yields a list of single code points,
none can be a sequence.
No %s allowed while running setuid
(F) Certain operations are deemed to be too insecure for a setuid or setgid script to
even be allowed to attempt. Generally speaking there will be another way to do what
you want that is, if not secure, at least securable. See perlsec.
No code specified for -%c
(F) Perl's -e and -E command-line options require an argument. If you want to run an
empty program, pass the empty string as a separate argument or run a program
consisting of a single 0 or 1:
perl -e ""
perl -e0
perl -e1
No comma allowed after %s
(F) A list operator that has a filehandle or "indirect object" is not allowed to have
a comma between that and the following arguments. Otherwise it'd be just another one
of the arguments.
One possible cause for this is that you expected to have imported a constant to your
name space with use or import while no such importing took place, it may for example
be that your operating system does not support that particular constant. Hopefully
you did use an explicit import list for the constants you expect to see; please see
"use" in perlfunc and "import" in perlfunc. While an explicit import list would
probably have caught this error earlier it naturally does not remedy the fact that
your operating system still does not support that constant. Maybe you have a typo in
the constants of the symbol import list of use or import or in the constant name at
the line where this error was triggered?
No command into which to pipe on command line
(F) An error peculiar to VMS. Perl handles its own command line redirection, and
found a '|' at the end of the command line, so it doesn't know where you want to pipe
the output from this command.
No DB::DB routine defined
(F) The currently executing code was compiled with the -d switch, but for some reason
the current debugger (e.g. perl5db.pl or a "Devel::" module) didn't define a routine
to be called at the beginning of each statement.
No dbm on this machine
(P) This is counted as an internal error, because every machine should supply dbm
nowadays, because Perl comes with SDBM. See SDBM_File.
No DB::sub routine defined
(F) The currently executing code was compiled with the -d switch, but for some reason
the current debugger (e.g. perl5db.pl or a "Devel::" module) didn't define a "DB::sub"
routine to be called at the beginning of each ordinary subroutine call.
No digits found for %s literal
(F) No hexadecimal digits were found following "0x" or no binary digits were found
following "0b".
No directory specified for -I
(F) The -I command-line switch requires a directory name as part of the same argument.
Use -Ilib, for instance. -I lib won't work.
No error file after 2> or 2>> on command line
(F) An error peculiar to VMS. Perl handles its own command line redirection, and
found a '2>' or a '2>>' on the command line, but can't find the name of the file to
which to write data destined for stderr.
No group ending character '%c' found in template
(F) A pack or unpack template has an opening '(' or '[' without its matching
counterpart. See "pack" in perlfunc.
No input file after < on command line
(F) An error peculiar to VMS. Perl handles its own command line redirection, and
found a '<' on the command line, but can't find the name of the file from which to
read data for stdin.
No next::method '%s' found for %s
(F) "next::method" found no further instances of this method name in the remaining
packages of the MRO of this class. If you don't want it throwing an exception, use
"maybe::next::method" or "next::can". See mro.
Non-finite repeat count does nothing
(W numeric) You tried to execute the "x" repetition operator "Inf" (or "-Inf") or
"NaN" times, which doesn't make sense.
Non-hex character in regex; marked by <-- HERE in m/%s/
(F) In a regular expression, there was a non-hexadecimal character where a hex one was
expected, like
(?[ [ \xDG ] ])
(?[ [ \x{DEKA} ] ])
Non-hex character '%c' terminates \x early. Resolved as "%s"
(W digit) In parsing a hexadecimal numeric constant, a character was unexpectedly
encountered that isn't hexadecimal. The resulting value is as indicated.
Note that, within braces, every character starting with the first non-hexadecimal up
to the ending brace is ignored.
Non-octal character in regex; marked by <-- HERE in m/%s/
(F) In a regular expression, there was a non-octal character where an octal one was
expected, like
(?[ [ \o{1278} ] ])
Non-octal character '%c' terminates \o early. Resolved as "%s"
(W digit) In parsing an octal numeric constant, a character was unexpectedly
encountered that isn't octal. The resulting value is as indicated.
When not using "\o{...}", you wrote something like "\08", or "\179" in a double-
quotish string. The resolution is as indicated, with all but the last digit treated
as a single character, specified in octal. The last digit is the next character in
the string. To tell Perl that this is indeed what you want, you can use the "\o{ }"
syntax, or use exactly three digits to specify the octal for the character.
Note that, within braces, every character starting with the first non-octal up to the
ending brace is ignored.
"no" not allowed in expression
(F) The "no" keyword is recognized and executed at compile time, and returns no useful
value. See perlmod.
Non-string passed as bitmask
(W misc) A number has been passed as a bitmask argument to select(). Use the vec()
function to construct the file descriptor bitmasks for select. See "select" in
perlfunc.
No output file after > on command line
(F) An error peculiar to VMS. Perl handles its own command line redirection, and
found a lone '>' at the end of the command line, so it doesn't know where you wanted
to redirect stdout.
No output file after > or >> on command line
(F) An error peculiar to VMS. Perl handles its own command line redirection, and
found a '>' or a '>>' on the command line, but can't find the name of the file to
which to write data destined for stdout.
No package name allowed for subroutine %s in "our"
No package name allowed for variable %s in "our"
(F) Fully qualified subroutine and variable names are not allowed in "our"
declarations, because that doesn't make much sense under existing rules. Such syntax
is reserved for future extensions.
No Perl script found in input
(F) You called "perl -x", but no line was found in the file beginning with #! and
containing the word "perl".
No setregid available
(F) Configure didn't find anything resembling the setregid() call for your system.
No setreuid available
(F) Configure didn't find anything resembling the setreuid() call for your system.
No such class %s
(F) You provided a class qualifier in a "my", "our" or "state" declaration, but this
class doesn't exist at this point in your program.
No such class field "%s" in variable %s of type %s
(F) You tried to access a key from a hash through the indicated typed variable but
that key is not allowed by the package of the same type. The indicated package has
restricted the set of allowed keys using the fields pragma.
No such hook: %s
(F) You specified a signal hook that was not recognized by Perl. Currently, Perl
accepts "__DIE__" and "__WARN__" as valid signal hooks.
No such pipe open
(P) An error peculiar to VMS. The internal routine my_pclose() tried to close a pipe
which hadn't been opened. This should have been caught earlier as an attempt to close
an unopened filehandle.
No such signal: SIG%s
(W signal) You specified a signal name as a subscript to %SIG that was not recognized.
Say "kill -l" in your shell to see the valid signal names on your system.
No Unicode property value wildcard matches:
(W regexp) You specified a wildcard for a Unicode property value, but there is no
property value in the current Unicode release that matches it. Check your spelling.
Not a CODE reference
(F) Perl was trying to evaluate a reference to a code value (that is, a subroutine),
but found a reference to something else instead. You can use the ref() function to
find out what kind of ref it really was. See also perlref.
Not a GLOB reference
(F) Perl was trying to evaluate a reference to a "typeglob" (that is, a symbol table
entry that looks like *foo), but found a reference to something else instead. You can
use the ref() function to find out what kind of ref it really was. See perlref.
Not a HASH reference
(F) Perl was trying to evaluate a reference to a hash value, but found a reference to
something else instead. You can use the ref() function to find out what kind of ref
it really was. See perlref.
'#' not allowed immediately following a sigil in a subroutine signature
(F) In a subroutine signature definition, a comment following a sigil ("$", "@" or
"%"), needs to be separated by whitespace or a comma etc., in particular to avoid
confusion with the $# variable. For example:
# bad
sub f ($# ignore first arg
, $y) {}
# good
sub f ($, # ignore first arg
$y) {}
Not an ARRAY reference
(F) Perl was trying to evaluate a reference to an array value, but found a reference
to something else instead. You can use the ref() function to find out what kind of
ref it really was. See perlref.
Not a SCALAR reference
(F) Perl was trying to evaluate a reference to a scalar value, but found a reference
to something else instead. You can use the ref() function to find out what kind of
ref it really was. See perlref.
Not a subroutine reference
(F) Perl was trying to evaluate a reference to a code value (that is, a subroutine),
but found a reference to something else instead. You can use the ref() function to
find out what kind of ref it really was. See also perlref.
Not a subroutine reference in overload table
(F) An attempt was made to specify an entry in an overloading table that doesn't
somehow point to a valid subroutine. See overload.
Not enough arguments for %s
(F) The function requires more arguments than you specified.
Not enough format arguments
(W syntax) A format specified more picture fields than the next line supplied. See
perlform.
%s: not found
(A) You've accidentally run your script through the Bourne shell instead of Perl.
Check the #! line, or manually feed your script into Perl yourself.
no UTC offset information; assuming local time is UTC
(S) A warning peculiar to VMS. Perl was unable to find the local timezone offset, so
it's assuming that local system time is equivalent to UTC. If it's not, define the
logical name SYS$TIMEZONE_DIFFERENTIAL to translate to the number of seconds which
need to be added to UTC to get local time.
NULL OP IN RUN
(S debugging) Some internal routine called run() with a null opcode pointer.
Null picture in formline
(F) The first argument to formline must be a valid format picture specification. It
was found to be empty, which probably means you supplied it an uninitialized value.
See perlform.
NULL regexp parameter
(P) The internal pattern matching routines are out of their gourd.
Number too long
(F) Perl limits the representation of decimal numbers in programs to about 250
characters. You've exceeded that length. Future versions of Perl are likely to
eliminate this arbitrary limitation. In the meantime, try using scientific notation
(e.g. "1e6" instead of "1_000_000").
Number with no digits
(F) Perl was looking for a number but found nothing that looked like a number. This
happens, for example with "\o{}", with no number between the braces.
Numeric format result too large
(F) The length of the result of a numeric format supplied to sprintf() or printf()
would have been too large for the underlying C function to report. This limit is
typically 2GB.
Numeric variables with more than one digit may not start with '0'
(F) The only numeric variable which is allowed to start with a 0 is $0, and you
mentioned a variable that starts with 0 that has more than one digit. You probably
want to remove the leading 0, or if the intent was to express a variable name in octal
you should convert to decimal.
Octal number > 037777777777 non-portable
(W portable) The octal number you specified is larger than 2**32-1 (4294967295) and
therefore non-portable between systems. See perlport for more on portability
concerns.
Odd name/value argument for subroutine '%s'
(F) A subroutine using a slurpy hash parameter in its signature received an odd number
of arguments to populate the hash. It requires the arguments to be paired, with the
same number of keys as values. The caller of the subroutine is presumably at fault.
The message attempts to include the name of the called subroutine. If the subroutine
has been aliased, the subroutine's original name will be shown, regardless of what
name the caller used.
Odd number of arguments for overload::constant
(W overload) The call to overload::constant contained an odd number of arguments. The
arguments should come in pairs.
Odd number of arguments passed to "%s" constructor
(S) The constructor for the given class was called with an odd number of arguments.
Class constructors accept named arguments as a list and expect pairs of name followed
by value as if you were initialising a hash.
Odd number of elements in anonymous hash
(W misc) You specified an odd number of elements to initialize a hash, which is odd,
because hashes come in key/value pairs.
Odd number of elements in export_lexically
(F) A call to "export_lexically" in builtin contained an odd number of arguments.
This is not permitted, because each name must be paired with a valid reference value.
Odd number of elements in hash assignment
(W misc) You specified an odd number of elements to initialize a hash, which is odd,
because hashes come in key/value pairs.
Odd number of elements in hash field initialization
(W misc) You specified an odd number of elements to initialise a hash field of an
object. Hashes are initialised from a list of key/value pairs so there must be a
corresponding value to every key. The final missing value will be filled in with
undef instead.
Offset outside string
(W layer) You tried to do a read/write/send/recv/seek operation with an offset
pointing outside the buffer. This is difficult to imagine. The sole exceptions to
this are that zero padding will take place when going past the end of the string when
either sysread()ing a file, or when seeking past the end of a scalar opened for I/O
(in anticipation of future reads and to imitate the behavior with real files).
Old package separator "'" deprecated
(D deprecated::apostrophe_as_package_separator, syntax) You used the old package
separator "'" in a variable, subroutine or package name. Support for the old package
separator will be removed in Perl 5.42.
Old package separator used in string
(D deprecated::apostrophe_as_package_separator, syntax) You used the old package
separator, "'", in a variable named inside a double-quoted string; e.g., "In $name's
house". This is equivalent to "In $name::s house". If you meant the former, put a
backslash before the apostrophe ("In $name\'s house").
Support for the old package separator will be removed in Perl 5.42.
Only scalar fields can take a :param attribute
(F) You tried to apply the ":param" attribute to an array or hash field. Currently
this is not permitted.
%s() on unopened %s
(W unopened) An I/O operation was attempted on a filehandle that was never
initialized. You need to do an open(), a sysopen(), or a socket() call, or call a
constructor from the FileHandle package.
-%s on unopened filehandle %s
(W unopened) You tried to invoke a file test operator on a filehandle that isn't open.
Check your control flow. See also "-X" in perlfunc.
oops: oopsAV
(S internal) An internal warning that the grammar is screwed up.
oops: oopsHV
(S internal) An internal warning that the grammar is screwed up.
Operand with no preceding operator in regex; marked by <-- HERE in m/%s/
(F) You wrote something like
(?[ \p{Digit} \p{Thai} ])
There are two operands, but no operator giving how you want to combine them.
Operation "%s": no method found, %s
(F) An attempt was made to perform an overloaded operation for which no handler was
defined. While some handlers can be autogenerated in terms of other handlers, there
is no default handler for any operation, unless the "fallback" overloading key is
specified to be true. See overload.
Operation "%s" returns its argument for non-Unicode code point 0x%X
(S non_unicode) You performed an operation requiring Unicode rules on a code point
that is not in Unicode, so what it should do is not defined. Perl has chosen to have
it do nothing, and warn you.
If the operation shown is "ToFold", it means that case-insensitive matching in a
regular expression was done on the code point.
If you know what you are doing you can turn off this warning by "no warnings
'non_unicode';".
Operation "%s" returns its argument for UTF-16 surrogate U+%X
(S surrogate) You performed an operation requiring Unicode rules on a Unicode
surrogate. Unicode frowns upon the use of surrogates for anything but storing strings
in UTF-16, but rules are (reluctantly) defined for the surrogates, and they are to do
nothing for this operation. Because the use of surrogates can be dangerous, Perl
warns.
If the operation shown is "ToFold", it means that case-insensitive matching in a
regular expression was done on the code point.
If you know what you are doing you can turn off this warning by "no warnings
'surrogate';".
Operator or semicolon missing before %s
(S ambiguous) You used a variable or subroutine call where the parser was expecting an
operator. The parser has assumed you really meant to use an operator, but this is
highly likely to be incorrect. For example, if you say "*foo *foo" it will be
interpreted as if you said "*foo * 'foo'".
Optional parameter lacks default expression
(F) In a subroutine signature, you wrote something like "$x =", making a named
optional parameter without a default value. A nameless optional parameter is
permitted to have no default value, but a named one must have a specific default. You
probably want "$x = undef".
"our" variable %s redeclared
(W shadow) You seem to have already declared the same global once before in the
current lexical scope.
Out of memory!
(X) The malloc() function returned 0, indicating there was insufficient remaining
memory (or virtual memory) to satisfy the request. Perl has no option but to exit
immediately.
At least in Unix you may be able to get past this by increasing your process datasize
limits: in csh/tcsh use "limit" and "limit datasize n" (where "n" is the number of
kilobytes) to check the current limits and change them, and in ksh/bash/zsh use
"ulimit -a" and "ulimit -d n", respectively.
Out of memory during %s extend
(X) An attempt was made to extend an array, a list, or a string beyond the largest
possible memory allocation.
Out of memory during "large" request for %s
(F) The malloc() function returned 0, indicating there was insufficient remaining
memory (or virtual memory) to satisfy the request. However, the request was judged
large enough (compile-time default is 64K), so a possibility to shut down by trapping
this error is granted.
Out of memory during request for %s
(X)(F) The malloc() function returned 0, indicating there was insufficient remaining
memory (or virtual memory) to satisfy the request.
The request was judged to be small, so the possibility to trap it depends on the way
perl was compiled. By default it is not trappable. However, if compiled for this,
Perl may use the contents of $^M as an emergency pool after die()ing with this
message. In this case the error is trappable once, and the error message will include
the line and file where the failed request happened.
Out of memory during ridiculously large request
(F) You can't allocate more than 2^31+"small amount" bytes. This error is most likely
to be caused by a typo in the Perl program. e.g., $arr[time] instead of $arr[$time].
Out of memory during vec in lvalue context
(F) An attempt was made to extend a string beyond the largest possible memory
allocation by assigning to vec() called with a large second argument.
Out of memory for yacc stack
(F) The yacc parser wanted to grow its stack so it could continue parsing, but
realloc() wouldn't give it more memory, virtual or otherwise.
Out of memory in perl:%s
(X) A low-level memory allocation routine failed, indicating there was insufficient
remaining (virtual) memory to satisfy the request. Perl has no option but to exit
immediately.
At least in Unix you may be able to get past this by increasing your process datasize
limits: in csh/tcsh use "limit" and "limit datasize n" (where "n" is the number of
kilobytes) to check the current limits and change them, and in ksh/bash/zsh use
"ulimit -a" and "ulimit -d n", respectively.
'.' outside of string in pack
(F) The argument to a '.' in your template tried to move the working position to
before the start of the packed string being built.
'@' outside of string in unpack
(F) You had a template that specified an absolute position outside the string being
unpacked. See "pack" in perlfunc.
'@' outside of string with malformed UTF-8 in unpack
(F) You had a template that specified an absolute position outside the string being
unpacked. The string being unpacked was also invalid UTF-8. See "pack" in perlfunc.
overload arg '%s' is invalid
(W overload) The overload pragma was passed an argument it did not recognize. Did you
mistype an operator?
Overloaded dereference did not return a reference
(F) An object with an overloaded dereference operator was dereferenced, but the
overloaded operation did not return a reference. See overload.
Overloaded qr did not return a REGEXP
(F) An object with a "qr" overload was used as part of a match, but the overloaded
operation didn't return a compiled regexp. See overload.
%s package attribute may clash with future reserved word: %s
(W reserved) A lowercase attribute name was used that had a package-specific handler.
That name might have a meaning to Perl itself some day, even though it doesn't yet.
Perhaps you should use a mixed-case attribute name, instead. See attributes.
pack/unpack repeat count overflow
(F) You can't specify a repeat count so large that it overflows your signed integers.
See "pack" in perlfunc.
page overflow
(W io) A single call to write() produced more lines than can fit on a page. See
perlform.
panic: %s
(P) An internal error.
panic: attempt to call %s in %s
(P) One of the file test operators entered a code branch that calls an ACL related-
function, but that function is not available on this platform. Earlier checks mean
that it should not be possible to enter this branch on this platform.
panic: child pseudo-process was never scheduled
(P) A child pseudo-process in the ithreads implementation on Windows was not scheduled
within the time period allowed and therefore was not able to initialize properly.
panic: ck_grep, type=%u
(P) Failed an internal consistency check trying to compile a grep.
panic: corrupt saved stack index %ld
(P) The savestack was requested to restore more localized values than there are in the
savestack.
panic: del_backref
(P) Failed an internal consistency check while trying to reset a weak reference.
panic: fold_constants JMPENV_PUSH returned %d
(P) While attempting folding constants an exception other than an "eval" failure was
caught.
panic: frexp: %f
(P) The library function frexp() failed, making printf("%f") impossible.
panic: goto, type=%u, ix=%ld
(P) We popped the context stack to a context with the specified label, and then
discovered it wasn't a context we know how to do a goto in.
panic: gp_free failed to free glob pointer
(P) The internal routine used to clear a typeglob's entries tried repeatedly, but each
time something re-created entries in the glob. Most likely the glob contains an
object with a reference back to the glob and a destructor that adds a new object to
the glob.
panic: INTERPCASEMOD, %s
(P) The lexer got into a bad state at a case modifier.
panic: INTERPCONCAT, %s
(P) The lexer got into a bad state parsing a string with brackets.
panic: kid popen errno read
(F) A forked child returned an incomprehensible message about its errno.
panic: leave_scope inconsistency %u
(P) The savestack probably got out of sync. At least, there was an invalid enum on
the top of it.
panic: magic_killbackrefs
(P) Failed an internal consistency check while trying to reset all weak references to
an object.
panic: malloc, %s
(P) Something requested a negative number of bytes of malloc.
panic: memory wrap
(P) Something tried to allocate either more memory than possible or a negative amount.
panic: newFORLOOP, %s
(P) The parser failed an internal consistency check while trying to parse a "foreach"
loop.
panic: pad_alloc, %p!=%p
(P) The compiler got confused about which scratch pad it was allocating and freeing
temporaries and lexicals from.
panic: pad_free curpad, %p!=%p
(P) The compiler got confused about which scratch pad it was allocating and freeing
temporaries and lexicals from.
panic: pad_free po
(P) A zero scratch pad offset was detected internally. An attempt was made to free a
target that had not been allocated to begin with.
panic: pad_reset curpad, %p!=%p
(P) The compiler got confused about which scratch pad it was allocating and freeing
temporaries and lexicals from.
panic: pad_sv po
(P) A zero scratch pad offset was detected internally. Most likely an operator needed
a target but that target had not been allocated for whatever reason.
panic: pad_swipe curpad, %p!=%p
(P) The compiler got confused about which scratch pad it was allocating and freeing
temporaries and lexicals from.
panic: pad_swipe po
(P) An invalid scratch pad offset was detected internally.
panic: pp_iter, type=%u
(P) The foreach iterator got called in a non-loop context frame.
panic: pp_match%s
(P) The internal pp_match() routine was called with invalid operational data.
panic: realloc, %s
(P) Something requested a negative number of bytes of realloc.
panic: reference miscount on nsv in sv_replace() (%d != 1)
(P) The internal sv_replace() function was handed a new SV with a reference count
other than 1.
panic: restartop in %s
(P) Some internal routine requested a goto (or something like it), and didn't supply
the destination.
panic: return, type=%u
(P) We popped the context stack to a subroutine or eval context, and then discovered
it wasn't a subroutine or eval context.
panic: scan_num, %s
(P) scan_num() got called on something that wasn't a number.
panic: Sequence (?{...}): no code block found in regex m/%s/
(P) While compiling a pattern that has embedded (?{}) or (??{}) code blocks, perl
couldn't locate the code block that should have already been seen and compiled by perl
before control passed to the regex compiler.
panic: sv_chop %s
(P) The sv_chop() routine was passed a position that is not within the scalar's string
buffer.
panic: sv_insert, midend=%p, bigend=%p
(P) The sv_insert() routine was told to remove more string than there was string.
panic: top_env
(P) The compiler attempted to do a goto, or something weird like that.
panic: unexpected constant lvalue entersub entry via type/targ %d:%d
(P) When compiling a subroutine call in lvalue context, Perl failed an internal
consistency check. It encountered a malformed op tree.
panic: unimplemented op %s (#%d) called
(P) The compiler is screwed up and attempted to use an op that isn't permitted at run
time.
panic: unknown OA_*: %x
(P) The internal routine that handles arguments to &CORE::foo() subroutine calls was
unable to determine what type of arguments were expected.
panic: utf16_to_utf8: odd bytelen
(P) Something tried to call utf16_to_utf8 with an odd (as opposed to even) byte
length.
panic: utf16_to_utf8_reversed: odd bytelen
(P) Something tried to call utf16_to_utf8_reversed with an odd (as opposed to even)
byte length.
panic: yylex, %s
(P) The lexer got into a bad state while processing a case modifier.
Parentheses missing around "%s" list
(W parenthesis) You said something like
my $foo, $bar = @_;
when you meant
my ($foo, $bar) = @_;
Remember that "my", "our", "local" and "state" bind tighter than comma.
Parsing code internal error (%s)
(F) Parsing code supplied by an extension violated the parser's API in a detectable
way.
Pattern subroutine nesting without pos change exceeded limit in regex
(F) You used a pattern that uses too many nested subpattern calls without consuming
any text. Restructure the pattern so text is consumed before the nesting limit is
exceeded.
"-p" destination: %s
(F) An error occurred during the implicit output invoked by the "-p" command-line
switch. (This output goes to STDOUT unless you've redirected it with select().)
Perl API version %s of %s does not match %s
(F) The XS module in question was compiled against a different incompatible version of
Perl than the one that has loaded the XS module.
Perl folding rules are not up-to-date for 0x%X; please use the perlbug utility to report;
in regex; marked by <-- HERE in m/%s/
(S regexp) You used a regular expression with case-insensitive matching, and there is
a bug in Perl in which the built-in regular expression folding rules are not accurate.
This may lead to incorrect results. Please report this as a bug to
<https://github.com/Perl/perl5/issues/new/choose>.
Perl_my_%s() not available
(F) Your platform has very uncommon byte-order and integer size, so it was not
possible to set up some or all fixed-width byte-order conversion functions. This is
only a problem when you're using the '<' or '>' modifiers in (un)pack templates. See
"pack" in perlfunc.
Perl %s required (did you mean %s?)--this is only %s, stopped
(F) The code you are trying to run has asked for a newer version of Perl than you are
running. Perhaps "use 5.10" was written instead of "use 5.010" or "use v5.10".
Without the leading "v", the number is interpreted as a decimal, with every three
digits after the decimal point representing a part of the version number. So 5.10 is
equivalent to v5.100.
Perl %s required--this is only %s, stopped
(F) The module in question uses features of a version of Perl more recent than the
currently running version. How long has it been since you upgraded, anyway? See
"require" in perlfunc.
PERL_SH_DIR too long
(F) An error peculiar to OS/2. PERL_SH_DIR is the directory to find the "sh"-shell
in. See "PERL_SH_DIR" in perlos2.
PERL_SIGNALS illegal: "%s"
(X) See "PERL_SIGNALS" in perlrun for legal values.
Perls since %s too modern--this is %s, stopped
(F) The code you are trying to run claims it will not run on the version of Perl you
are using because it is too new. Maybe the code needs to be updated, or maybe it is
simply wrong and the version check should just be removed.
perl: warning: Non hex character in '$ENV{PERL_HASH_SEED}', seed only partially set
(S) PERL_HASH_SEED should match /^\s*(?:0x)?[0-9a-fA-F]+\s*\z/ but it contained a non
hex character. This could mean you are not using the hash seed you think you are.
perl: warning: Setting locale failed.
(S) The whole warning message will look something like:
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LC_ALL = "En_US",
LANG = (unset)
are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
Exactly what were the failed locale settings varies. In the above the settings were
that the LC_ALL was "En_US" and the LANG had no value. This error means that Perl
detected that you and/or your operating system supplier and/or system administrator
have set up the so-called locale system but Perl could not use those settings. This
was not dead serious, fortunately: there is a "default locale" called "C" that Perl
can and will use, and the script will be run. Before you really fix the problem,
however, you will get the same error message each time you run Perl. How to really
fix the problem can be found in perllocale section LOCALE PROBLEMS.
perl: warning: strange setting in '$ENV{PERL_PERTURB_KEYS}': '%s'
(S) Perl was run with the environment variable PERL_PERTURB_KEYS defined but
containing an unexpected value. The legal values of this setting are as follows.
Numeric | String | Result
--------+---------------+-----------------------------------------
0 | NO | Disables key traversal randomization
1 | RANDOM | Enables full key traversal randomization
2 | DETERMINISTIC | Enables repeatable key traversal
| | randomization
Both numeric and string values are accepted, but note that string values are case
sensitive. The default for this setting is "RANDOM" or 1.
pid %x not a child
(W exec) A warning peculiar to VMS. Waitpid() was asked to wait for a process which
isn't a subprocess of the current process. While this is fine from VMS' perspective,
it's probably not what you intended.
'P' must have an explicit size in unpack
(F) The unpack format P must have an explicit size, not "*".
POSIX class [:%s:] unknown in regex; marked by <-- HERE in m/%s/
(F) The class in the character class [: :] syntax is unknown. The <-- HERE shows
whereabouts in the regular expression the problem was discovered. Note that the POSIX
character classes do not have the "is" prefix the corresponding C interfaces have: in
other words, it's "[[:print:]]", not "isprint". See perlre.
POSIX getpgrp can't take an argument
(F) Your system has POSIX getpgrp(), which takes no argument, unlike the BSD version,
which takes a pid.
POSIX syntax [%c %c] belongs inside character classes%s in regex; marked by <-- HERE in
m/%s/
(W regexp) Perl thinks that you intended to write a POSIX character class, but didn't
use enough brackets. These POSIX class constructs [: :], [= =], and [. .] go inside
character classes, the [] are part of the construct, for example:
"qr/[012[:alpha:]345]/". What the regular expression pattern compiled to is probably
not what you were intending. For example, "qr/[:alpha:]/" compiles to a regular
bracketed character class consisting of the four characters ":", "a", "l", "h", and
"p". To specify the POSIX class, it should have been written "qr/[[:alpha:]]/".
Note that [= =] and [. .] are not currently implemented; they are simply placeholders
for future extensions and will cause fatal errors. The <-- HERE shows whereabouts in
the regular expression the problem was discovered. See perlre.
If the specification of the class was not completely valid, the message indicates
that.
POSIX syntax [. .] is reserved for future extensions in regex; marked by <-- HERE in m/%s/
(F) Within regular expression character classes ([]) the syntax beginning with "[."
and ending with ".]" is reserved for future extensions. If you need to represent
those character sequences inside a regular expression character class, just quote the
square brackets with the backslash: "\[." and ".\]". The <-- HERE shows whereabouts
in the regular expression the problem was discovered. See perlre.
POSIX syntax [= =] is reserved for future extensions in regex; marked by <-- HERE in m/%s/
(F) Within regular expression character classes ([]) the syntax beginning with "[="
and ending with "=]" is reserved for future extensions. If you need to represent
those character sequences inside a regular expression character class, just quote the
square brackets with the backslash: "\[=" and "=\]". The <-- HERE shows whereabouts
in the regular expression the problem was discovered. See perlre.
Possible attempt to put comments in qw() list
(W qw) qw() lists contain items separated by whitespace; as with literal strings,
comment characters are not ignored, but are instead treated as literal data. (You may
have used different delimiters than the parentheses shown here; braces are also
frequently used.)
You probably wrote something like this:
@list = qw(
a # a comment
b # another comment
);
when you should have written this:
@list = qw(
a
b
);
If you really want comments, build your list the old-fashioned way, with quotes and
commas:
@list = (
'a', # a comment
'b', # another comment
);
Possible attempt to separate words with commas
(W qw) qw() lists contain items separated by whitespace; therefore commas aren't
needed to separate the items. (You may have used different delimiters than the
parentheses shown here; braces are also frequently used.)
You probably wrote something like this:
qw! a, b, c !;
which puts literal commas into some of the list items. Write it without commas if you
don't want them to appear in your data:
qw! a b c !;
Possible memory corruption: %s overflowed 3rd argument
(F) An ioctl() or fcntl() returned more than Perl was bargaining for. Perl guesses a
reasonable buffer size, but puts a sentinel byte at the end of the buffer just in
case. This sentinel byte got clobbered, and Perl assumes that memory is now
corrupted. See "ioctl" in perlfunc.
Possible precedence issue with control flow operator (%s)
(W syntax) There is a possible problem with the mixing of a control flow operator
(e.g. "return") and a low-precedence operator like "or". Consider:
sub { return $x or $y; }
This is parsed as:
sub { (return $x) or $y; }
Which is effectively just:
sub { return $x; }
Either use parentheses or the high-precedence variant of the operator.
Note this may be also triggered for constructs like:
sub { 1 if die; }
Possible precedence problem on bitwise %s operator
(W precedence) Your program uses a bitwise logical operator in conjunction with a
numeric comparison operator, like this :
if ($x & $y == 0) { ... }
This expression is actually equivalent to "$x & ($y == 0)", due to the higher
precedence of "==". This is probably not what you want. (If you really meant to
write this, disable the warning, or, better, put the parentheses explicitly and write
"$x & ($y == 0)").
Possible unintended interpolation of $\ in regex
(W ambiguous) You said something like "m/$\/" in a regex. The regex "m/foo$\s+bar/m"
translates to: match the word 'foo', the output record separator (see "$\" in perlvar)
and the letter 's' (one time or more) followed by the word 'bar'.
If this is what you intended then you can silence the warning by using "m/${\}/" (for
example: "m/foo${\}s+bar/").
If instead you intended to match the word 'foo' at the end of the line followed by
whitespace and the word 'bar' on the next line then you can use "m/$(?)\/" (for
example: "m/foo$(?)\s+bar/").
Possible unintended interpolation of %s in string
(W ambiguous) You said something like '@foo' in a double-quoted string but there was
no array @foo in scope at the time. If you wanted a literal @foo, then write it as
\@foo; otherwise find out what happened to the array you apparently lost track of.
Precedence problem: open %s should be open(%s)
(S precedence) The old irregular construct
open FOO || die;
is now misinterpreted as
open(FOO || die);
because of the strict regularization of Perl 5's grammar into unary and list
operators. (The old open was a little of both.) You must put parentheses around the
filehandle, or use the new "or" operator instead of "||".
Premature end of script headers
See "500 Server error".
printf() on closed filehandle %s
(W closed) The filehandle you're writing to got itself closed sometime before now.
Check your control flow.
print() on closed filehandle %s
(W closed) The filehandle you're printing on got itself closed sometime before now.
Check your control flow.
Process terminated by SIG%s
(W) This is a standard message issued by OS/2 applications, while *nix applications
die in silence. It is considered a feature of the OS/2 port. One can easily disable
this by appropriate sighandlers, see "Signals" in perlipc. See also "Process
terminated by SIGTERM/SIGINT" in perlos2.
Prototype after '%c' for %s : %s
(W illegalproto) A character follows % or @ in a prototype. This is useless, since %
and @ gobble the rest of the subroutine arguments.
Prototype mismatch: %s vs %s
(S prototype) The subroutine being declared or defined had previously been declared or
defined with a different function prototype.
Prototype not terminated
(F) You've omitted the closing parenthesis in a function prototype definition.
Prototype '%s' overridden by attribute 'prototype(%s)' in %s
(W prototype) A prototype was declared in both the parentheses after the sub name and
via the prototype attribute. The prototype in parentheses is useless, since it will
be replaced by the prototype from the attribute before it's ever used.
%s on BEGIN block ignored
(W syntax) "BEGIN" blocks are executed immediately after they are parsed and then
thrown away. Any prototypes or attributes are therefore meaningless and are ignored.
You should remove them from the "BEGIN" block. Note this also means you cannot create
a constant called "BEGIN".
Quantifier follows nothing in regex; marked by <-- HERE in m/%s/
(F) You started a regular expression with a quantifier. Backslash it if you meant it
literally. The <-- HERE shows whereabouts in the regular expression the problem was
discovered. See perlre.
Quantifier in {,} bigger than %d in regex; marked by <-- HERE in m/%s/
(F) There is currently a limit to the size of the min and max values of the {min,max}
construct. The <-- HERE shows whereabouts in the regular expression the problem was
discovered. See perlre.
Quantifier {n,m} with n > m can't match in regex
Quantifier {n,m} with n > m can't match in regex; marked by <-- HERE in m/%s/
(W regexp) Minima should be less than or equal to maxima. If you really want your
regexp to match something 0 times, just put {0}.
Quantifier unexpected on zero-length expression in regex m/%s/
(W regexp) You applied a regular expression quantifier in a place where it makes no
sense, such as on a zero-width assertion. Try putting the quantifier inside the
assertion instead. For example, the way to match "abc" provided that it is followed
by three repetitions of "xyz" is "/abc(?=(?:xyz){3})/", not "/abc(?=xyz){3}/".
Range iterator outside integer range
(F) One (or both) of the numeric arguments to the range operator ".." are outside the
range which can be represented by integers internally. One possible workaround is to
force Perl to use magical string increment by prepending "0" to your numbers.
Ranges of ASCII printables should be some subset of "0-9", "A-Z", or "a-z" in regex;
marked by <-- HERE in m/%s/
(W regexp) (only under "use re 'strict'" or within "(?[...])")
Stricter rules help to find typos and other errors. Perhaps you didn't even intend a
range here, if the "-" was meant to be some other character, or should have been
escaped (like "\-"). If you did intend a range, the one that was used is not portable
between ASCII and EBCDIC platforms, and doesn't have an obvious meaning to a casual
reader.
[3-7] # OK; Obvious and portable
[d-g] # OK; Obvious and portable
[A-Y] # OK; Obvious and portable
[A-z] # WRONG; Not portable; not clear what is meant
[a-Z] # WRONG; Not portable; not clear what is meant
[%-.] # WRONG; Not portable; not clear what is meant
[\x41-Z] # WRONG; Not portable; not obvious to non-geek
(You can force portability by specifying a Unicode range, which means that the
endpoints are specified by "\N{...}", but the meaning may still not be obvious.) The
stricter rules require that ranges that start or stop with an ASCII character that is
not a control have all their endpoints be the literal character, and not some escape
sequence (like "\x41"), and the ranges must be all digits, or all uppercase letters,
or all lowercase letters.
Ranges of digits should be from the same group in regex; marked by <-- HERE in m/%s/
(W regexp) (only under "use re 'strict'" or within "(?[...])")
Stricter rules help to find typos and other errors. You included a range, and at
least one of the end points is a decimal digit. Under the stricter rules, when this
happens, both end points should be digits in the same group of 10 consecutive digits.
readdir() attempted on invalid dirhandle %s
(W io) The dirhandle you're reading from is either closed or not really a dirhandle.
Check your control flow.
readline() on closed filehandle %s
(W closed) The filehandle you're reading from got itself closed sometime before now.
Check your control flow.
readline() on unopened filehandle %s
(W unopened) The filehandle you're reading from was never opened. Check your control
flow.
read() on closed filehandle %s
(W closed) You tried to read from a closed filehandle.
read() on unopened filehandle %s
(W unopened) You tried to read from a filehandle that was never opened.
realloc() of freed memory ignored
(S malloc) An internal routine called realloc() on something that had already been
freed.
Recompile perl with -DDEBUGGING to use -D switch
(S debugging) You can't use the -D option unless the code to produce the desired
output is compiled into Perl, which entails some overhead, which is why it's currently
left out of your copy.
Recursive call to Perl_load_module in PerlIO_find_layer
(P) It is currently not permitted to load modules when creating a filehandle inside an
%INC hook. This can happen with "open my $fh, '<', \$scalar", which implicitly loads
PerlIO::scalar. Try loading PerlIO::scalar explicitly first.
Recursive inheritance detected in package '%s'
(F) While calculating the method resolution order (MRO) of a package, Perl believes it
found an infinite loop in the @ISA hierarchy. This is a crude check that bails out
after 100 levels of @ISA depth.
Redundant argument in %s
(W redundant) You called a function with more arguments than other arguments you
supplied indicated would be needed. Currently only emitted when a printf-type format
required fewer arguments than were supplied, but might be used in the future for e.g.
"pack" in perlfunc.
refcnt_dec: fd %d%s
refcnt: fd %d%s
refcnt_inc: fd %d%s
(P) Perl's I/O implementation failed an internal consistency check. If you see this
message, something is very wrong.
Reference found where even-sized list expected
(W misc) You gave a single reference where Perl was expecting a list with an even
number of elements (for assignment to a hash). This usually means that you used the
anon hash constructor when you meant to use parens. In any case, a hash requires
key/value pairs.
%hash = { one => 1, two => 2, }; # WRONG
%hash = [ qw/ an anon array / ]; # WRONG
%hash = ( one => 1, two => 2, ); # right
%hash = qw( one 1 two 2 ); # also fine
Reference is already weak
(W misc) You have attempted to weaken a reference that is already weak. Doing so has
no effect.
Reference is not weak
(W misc) You have attempted to unweaken a reference that is not weak. Doing so has no
effect.
Reference to invalid group 0 in regex; marked by <-- HERE in m/%s/
(F) You used "\g0" or similar in a regular expression. You may refer to capturing
parentheses only with strictly positive integers (normal backreferences) or with
strictly negative integers (relative backreferences). Using 0 does not make sense.
Reference to nonexistent group in regex; marked by <-- HERE in m/%s/
(F) You used something like "\7" in your regular expression, but there are not at
least seven sets of capturing parentheses in the expression. If you wanted to have
the character with ordinal 7 inserted into the regular expression, prepend zeroes to
make it three digits long: "\007"
The <-- HERE shows whereabouts in the regular expression the problem was discovered.
Reference to nonexistent named group in regex; marked by <-- HERE in m/%s/
(F) You used something like "\k'NAME'" or "\k<NAME>" in your regular expression, but
there is no corresponding named capturing parentheses such as "(?'NAME'...)" or
"(?<NAME>...)". Check if the name has been spelled correctly both in the
backreference and the declaration.
The <-- HERE shows whereabouts in the regular expression the problem was discovered.
Reference to nonexistent or unclosed group in regex; marked by <-- HERE in m/%s/
(F) You used something like "\g{-7}" in your regular expression, but there are not at
least seven sets of closed capturing parentheses in the expression before where the
"\g{-7}" was located.
The <-- HERE shows whereabouts in the regular expression the problem was discovered.
regexp memory corruption
(P) The regular expression engine got confused by what the regular expression compiler
gave it.
Regexp modifier "/%c" may appear a maximum of twice
Regexp modifier "%c" may appear a maximum of twice in regex; marked by <-- HERE in m/%s/
(F) The regular expression pattern had too many occurrences of the specified modifier.
Remove the extraneous ones.
Regexp modifier "%c" may not appear after the "-" in regex; marked by <-- HERE in m/%s/
(F) Turning off the given modifier has the side effect of turning on another one.
Perl currently doesn't allow this. Reword the regular expression to use the modifier
you want to turn on (and place it before the minus), instead of the one you want to
turn off.
Regexp modifier "/%c" may not appear twice
Regexp modifier "%c" may not appear twice in regex; marked by <-- HERE in m/%s/
(F) The regular expression pattern had too many occurrences of the specified modifier.
Remove the extraneous ones.
Regexp modifiers "/%c" and "/%c" are mutually exclusive
Regexp modifiers "%c" and "%c" are mutually exclusive in regex; marked by <-- HERE in
m/%s/
(F) The regular expression pattern had more than one of these mutually exclusive
modifiers. Retain only the modifier that is supposed to be there.
Regexp out of space in regex m/%s/
(P) A "can't happen" error, because safemalloc() should have caught it earlier.
Repeated format line will never terminate (~~ and @#)
(F) Your format contains the ~~ repeat-until-blank sequence and a numeric field that
will never go blank so that the repetition never terminates. You might use ^#
instead. See perlform.
Replacement list is longer than search list
(W misc) You have used a replacement list that is longer than the search list. So the
additional elements in the replacement list are meaningless.
Required parameter '%s' is missing for %s constructor
(F) You called the constructor for a class that has a required named parameter, but
did not pass that parameter at all.
'(*%s' requires a terminating ':' in regex; marked by <-- HERE in m/%s/
(F) You used a construct that needs a colon and pattern argument. Supply these or
check that you are using the right construct.
'%s' resolved to '\o{%s}%d'
As of Perl 5.32, this message is no longer generated. Instead, see "Non-octal
character '%c' terminates \o early. Resolved as "%s"". (W misc, regexp) You wrote
something like "\08", or "\179" in a double-quotish string. All but the last digit is
treated as a single character, specified in octal. The last digit is the next
character in the string. To tell Perl that this is indeed what you want, you can use
the "\o{ }" syntax, or use exactly three digits to specify the octal for the
character.
Reversed %s= operator
(W syntax) You wrote your assignment operator backwards. The = must always come last,
to avoid ambiguity with subsequent unary operators.
rewinddir() attempted on invalid dirhandle %s
(W io) The dirhandle you tried to do a rewinddir() on is either closed or not really a
dirhandle. Check your control flow.
Scalars leaked: %d
(S internal) Something went wrong in Perl's internal bookkeeping of scalars: not all
scalar variables were deallocated by the time Perl exited. What this usually
indicates is a memory leak, which is of course bad, especially if the Perl program is
intended to be long-running.
Scalar value @%s[%s] better written as $%s[%s]
(W syntax) You've used an array slice (indicated by @) to select a single element of
an array. Generally it's better to ask for a scalar value (indicated by $). The
difference is that $foo[&bar] always behaves like a scalar, both when assigning to it
and when evaluating its argument, while @foo[&bar] behaves like a list when you assign
to it, and provides a list context to its subscript, which can do weird things if
you're expecting only one subscript.
On the other hand, if you were actually hoping to treat the array element as a list,
you need to look into how references work, because Perl will not magically convert
between scalars and lists for you. See perlref.
Scalar value @%s{%s} better written as $%s{%s}
(W syntax) You've used a hash slice (indicated by @) to select a single element of a
hash. Generally it's better to ask for a scalar value (indicated by $). The
difference is that $foo{&bar} always behaves like a scalar, both when assigning to it
and when evaluating its argument, while @foo{&bar} behaves like a list when you assign
to it, and provides a list context to its subscript, which can do weird things if
you're expecting only one subscript.
On the other hand, if you were actually hoping to treat the hash element as a list,
you need to look into how references work, because Perl will not magically convert
between scalars and lists for you. See perlref.
Search pattern not terminated
(F) The lexer couldn't find the final delimiter of a // or m{} construct. Remember
that bracketing delimiters count nesting level. Missing the leading "$" from a
variable $m may cause this error.
Note that since Perl 5.10.0 a // can also be the defined-or construct, not just the
empty search pattern. Therefore code written in Perl 5.10.0 or later that uses the //
as the defined-or can be misparsed by pre-5.10.0 Perls as a non-terminated search
pattern.
seekdir() attempted on invalid dirhandle %s
(W io) The dirhandle you are doing a seekdir() on is either closed or not really a
dirhandle. Check your control flow.
%sseek() on unopened filehandle
(W unopened) You tried to use the seek() or sysseek() function on a filehandle that
was either never opened or has since been closed.
select not implemented
(F) This machine doesn't implement the select() system call.
Self-ties of arrays and hashes are not supported
(F) Self-ties are of arrays and hashes are not supported in the current
implementation.
Semicolon seems to be missing
(W semicolon) A nearby syntax error was probably caused by a missing semicolon, or
possibly some other missing operator, such as a comma.
semi-panic: attempt to dup freed string
(S internal) The internal newSVsv() routine was called to duplicate a scalar that had
previously been marked as free.
sem%s not implemented
(F) You don't have System V semaphore IPC on your system.
send() on closed socket %s
(W closed) The socket you're sending to got itself closed sometime before now. Check
your control flow.
Sequence "\c{" invalid
(F) These three characters may not appear in sequence in a double-quotish context.
This message is raised only on non-ASCII platforms (a different error message is
output on ASCII ones). If you were intending to specify a control character with this
sequence, you'll have to use a different way to specify it.
Sequence (? incomplete in regex; marked by <-- HERE in m/%s/
(F) A regular expression ended with an incomplete extension (?. The <-- HERE shows
whereabouts in the regular expression the problem was discovered. See perlre.
Sequence (?%c...) not implemented in regex; marked by <-- HERE in m/%s/
(F) A proposed regular expression extension has the character reserved but has not yet
been written. The <-- HERE shows whereabouts in the regular expression the problem
was discovered. See perlre.
Sequence (?%s...) not recognized in regex; marked by <-- HERE in m/%s/
(F) You used a regular expression extension that doesn't make sense. The <-- HERE
shows whereabouts in the regular expression the problem was discovered. This may
happen when using the "(?^...)" construct to tell Perl to use the default regular
expression modifiers, and you redundantly specify a default modifier. For other
causes, see perlre.
Sequence (?#... not terminated in regex m/%s/
(F) A regular expression comment must be terminated by a closing parenthesis.
Embedded parentheses aren't allowed. See perlre.
Sequence (?&... not terminated in regex; marked by <-- HERE in m/%s/
(F) A named reference of the form "(?&...)" was missing the final closing parenthesis
after the name. The <-- HERE shows whereabouts in the regular expression the problem
was discovered.
Sequence (?%c... not terminated in regex; marked by <-- HERE in m/%s/
(F) A named group of the form "(?'...')" or "(?<...>)" was missing the final closing
quote or angle bracket. The <-- HERE shows whereabouts in the regular expression the
problem was discovered.
Sequence (%s... not terminated in regex; marked by <-- HERE in m/%s/
(F) A lookahead assertion "(?=...)" or "(?!...)" or lookbehind assertion "(?<=...)" or
"(?<!...)" was missing the final closing parenthesis. The <-- HERE shows whereabouts
in the regular expression the problem was discovered.
Sequence (?(%c... not terminated in regex; marked by <-- HERE in m/%s/
(F) A named reference of the form "(?('...')...)" or "(?(<...>)...)" was missing the
final closing quote or angle bracket after the name. The <-- HERE shows whereabouts
in the regular expression the problem was discovered.
Sequence (?... not terminated in regex; marked by <-- HERE in m/%s/
(F) There was no matching closing parenthesis for the '('. The <-- HERE shows
whereabouts in the regular expression the problem was discovered.
Sequence \%s... not terminated in regex; marked by <-- HERE in m/%s/
(F) The regular expression expects a mandatory argument following the escape sequence
and this has been omitted or incorrectly written.
Sequence (?{...}) not terminated with ')'
(F) The end of the perl code contained within the {...} must be followed immediately
by a ')'.
Sequence (?P>... not terminated in regex; marked by <-- HERE in m/%s/
(F) A named reference of the form "(?P>...)" was missing the final closing parenthesis
after the name. The <-- HERE shows whereabouts in the regular expression the problem
was discovered.
Sequence (?P<... not terminated in regex; marked by <-- HERE in m/%s/
(F) A named group of the form "(?P<...>')" was missing the final closing angle
bracket. The <-- HERE shows whereabouts in the regular expression the problem was
discovered.
Sequence ?P=... not terminated in regex; marked by <-- HERE in m/%s/
(F) A named reference of the form "(?P=...)" was missing the final closing parenthesis
after the name. The <-- HERE shows whereabouts in the regular expression the problem
was discovered.
Sequence (?R) not terminated in regex m/%s/
(F) An "(?R)" or "(?0)" sequence in a regular expression was missing the final
parenthesis.
500 Server error
(A) This is the error message generally seen in a browser window when trying to run a
CGI program (including SSI) over the web. The actual error text varies widely from
server to server. The most frequently-seen variants are "500 Server error", "Method
(something) not permitted", "Document contains no data", "Premature end of script
headers", and "Did not produce a valid header".
This is a CGI error, not a Perl error.
You need to make sure your script is executable, is accessible by the user CGI is
running the script under (which is probably not the user account you tested it under),
does not rely on any environment variables (like PATH) from the user it isn't running
under, and isn't in a location where the CGI server can't find it, basically, more or
less. Please see the following for more information:
https://www.perl.org/CGI_MetaFAQ.html
http://www.htmlhelp.org/faq/cgifaq.html
http://www.w3.org/Security/Faq/
You should also look at perlfaq9.
setegid() not implemented
(F) You tried to assign to $), and your operating system doesn't support the setegid()
system call (or equivalent), or at least Configure didn't think so.
seteuid() not implemented
(F) You tried to assign to $>, and your operating system doesn't support the seteuid()
system call (or equivalent), or at least Configure didn't think so.
setpgrp can't take arguments
(F) Your system has the setpgrp() from BSD 4.2, which takes no arguments, unlike POSIX
setpgid(), which takes a process ID and process group ID.
setrgid() not implemented
(F) You tried to assign to $(, and your operating system doesn't support the setrgid()
system call (or equivalent), or at least Configure didn't think so.
setruid() not implemented
(F) You tried to assign to $<, and your operating system doesn't support the setruid()
system call (or equivalent), or at least Configure didn't think so.
setsockopt() on closed socket %s
(W closed) You tried to set a socket option on a closed socket. Did you forget to
check the return value of your socket() call? See "setsockopt" in perlfunc.
Setting $/ to a reference to %s is forbidden
(F) You assigned a reference to a scalar to $/ where the referenced item is not a
positive integer. In older perls this appeared to work the same as setting it to
"undef" but was in fact internally different, less efficient and with very bad luck
could have resulted in your file being split by a stringified form of the reference.
In Perl 5.20.0 this was changed so that it would be exactly the same as setting $/ to
undef, with the exception that this warning would be thrown.
You are recommended to change your code to set $/ to "undef" explicitly if you wish to
slurp the file. As of Perl 5.28 assigning $/ to a reference to an integer which isn't
positive is a fatal error.
Setting $/ to %s reference is forbidden
(F) You tried to assign a reference to a non integer to $/. In older Perls this would
have behaved similarly to setting it to a reference to a positive integer, where the
integer was the address of the reference. As of Perl 5.20.0 this is a fatal error, to
allow future versions of Perl to use non-integer refs for more interesting purposes.
shm%s not implemented
(F) You don't have System V shared memory IPC on your system.
!=~ should be !~
(W syntax) The non-matching operator is !~, not !=~. !=~ will be interpreted as the
!= (numeric not equal) and ~ (1's complement) operators: probably not what you
intended.
/%s/ should probably be written as "%s"
(W syntax) You have used a pattern where Perl expected to find a string, as in the
first argument to "join". Perl will treat the true or false result of matching the
pattern against $_ as the string, which is probably not what you had in mind.
shutdown() on closed socket %s
(W closed) You tried to do a shutdown on a closed socket. Seems a bit superfluous.
SIG%s handler "%s" not defined
(W signal) The signal handler named in %SIG doesn't, in fact, exist. Perhaps you put
it into the wrong package?
Slab leaked from cv %p
(S) If you see this message, then something is seriously wrong with the internal
bookkeeping of op trees. An op tree needed to be freed after a compilation error, but
could not be found, so it was leaked instead.
sleep(%u) too large
(W overflow) You called "sleep" with a number that was larger than it can reliably
handle and "sleep" probably slept for less time than requested.
Slurpy parameter not last
(F) In a subroutine signature, you put something after a slurpy (array or hash)
parameter. The slurpy parameter takes all the available arguments, so there can't be
any left to fill later parameters.
Smart matching a non-overloaded object breaks encapsulation
(F) You should not use the "~~" operator on an object that does not overload it: Perl
refuses to use the object's underlying structure for the smart match.
Smartmatch is deprecated
(D deprecated::smartmatch) This warning is emitted if you use the smartmatch ("~~")
operator. This is a deprecated feature. Particularly, its behavior is noticed for
being unnecessarily complex and unintuitive, and it will be removed in Perl 5.42.
Sorry, hash keys must be smaller than 2**31 bytes
(F) You tried to create a hash containing a very large key, where "very large" means
that it needs at least 2 gigabytes to store. Unfortunately, Perl doesn't yet handle
such large hash keys. You should reconsider your design to avoid hashing such a long
string directly.
sort is now a reserved word
(F) An ancient error message that almost nobody ever runs into anymore. But before
sort was a keyword, people sometimes used it as a filehandle.
Source filters apply only to byte streams
(F) You tried to activate a source filter (usually by loading a source filter module)
within a string passed to "eval". This is not permitted under the "unicode_eval"
feature. Consider using "evalbytes" instead. See feature.
splice() offset past end of array
(W misc) You attempted to specify an offset that was past the end of the array passed
to splice(). Splicing will instead commence at the end of the array, rather than past
it. If this isn't what you want, try explicitly pre-extending the array by assigning
$#array = $offset. See "splice" in perlfunc.
Split loop
(P) The split was looping infinitely. (Obviously, a split shouldn't iterate more
times than there are characters of input, which is what happened.) See "split" in
perlfunc.
Statement unlikely to be reached
(W exec) You did an exec() with some statement after it other than a die(). This is
almost always an error, because exec() never returns unless there was a failure. You
probably wanted to use system() instead, which does return. To suppress this warning,
put the exec() in a block by itself.
"state" subroutine %s can't be in a package
(F) Lexically scoped subroutines aren't in a package, so it doesn't make sense to try
to declare one with a package qualifier on the front.
"state %s" used in sort comparison
(W syntax) The package variables $a and $b are used for sort comparisons. You used $a
or $b in as an operand to the "<=>" or "cmp" operator inside a sort comparison block,
and the variable had earlier been declared as a lexical variable. Either qualify the
sort variable with the package name, or rename the lexical variable.
"state" variable %s can't be in a package
(F) Lexically scoped variables aren't in a package, so it doesn't make sense to try to
declare one with a package qualifier on the front. Use local() if you want to
localize a package variable.
stat() on unopened filehandle %s
(W unopened) You tried to use the stat() function on a filehandle that was either
never opened or has since been closed.
Strings with code points over 0xFF may not be mapped into in-memory file handles
(W utf8) You tried to open a reference to a scalar for read or append where the scalar
contained code points over 0xFF. In-memory files model on-disk files and can only
contain bytes.
Stub found while resolving method "%s" overloading "%s" in package "%s"
(P) Overloading resolution over @ISA tree may be broken by importation stubs. Stubs
should never be implicitly created, but explicit calls to "can" may break this.
Subroutine attributes must come before the signature
(F) When subroutine signatures are enabled, any subroutine attributes must come before
the signature. Note that this order was the opposite in versions 5.22..5.26. So:
sub foo :lvalue ($x, $y) { ... } # 5.20 and 5.28 +
sub foo ($x, $y) :lvalue { ... } # 5.22 .. 5.26
Subroutine "&%s" is not available
(W closure) During compilation, an inner named subroutine or eval is attempting to
capture an outer lexical subroutine that is not currently available. This can happen
for one of two reasons. First, the lexical subroutine may be declared in an outer
anonymous subroutine that has not yet been created. (Remember that named subs are
created at compile time, while anonymous subs are created at run-time.) For example,
sub { my sub a {...} sub f { \&a } }
At the time that f is created, it can't capture the current "a" sub, since the
anonymous subroutine hasn't been created yet. Conversely, the following won't give a
warning since the anonymous subroutine has by now been created and is live:
sub { my sub a {...} eval 'sub f { \&a }' }->();
The second situation is caused by an eval accessing a lexical subroutine that has gone
out of scope, for example,
sub f {
my sub a {...}
sub { eval '\&a' }
}
f()->();
Here, when the '\&a' in the eval is being compiled, f() is not currently being
executed, so its &a is not available for capture.
"%s" subroutine &%s masks earlier declaration in same %s
(W shadow) A "my" or "state" subroutine has been redeclared in the current scope or
statement, effectively eliminating all access to the previous instance. This is
almost always a typographical error. Note that the earlier subroutine will still
exist until the end of the scope or until all closure references to it are destroyed.
Subroutine %s redefined
(W redefine) You redefined a subroutine. To suppress this warning, say
{
no warnings 'redefine';
eval "sub name { ... }";
}
Subroutine "%s" will not stay shared
(W closure) An inner (nested) named subroutine is referencing a "my" subroutine
defined in an outer named subroutine.
When the inner subroutine is called, it will see the value of the outer subroutine's
lexical subroutine as it was before and during the *first* call to the outer
subroutine; in this case, after the first call to the outer subroutine is complete,
the inner and outer subroutines will no longer share a common value for the lexical
subroutine. In other words, it will no longer be shared. This will especially make a
difference if the lexical subroutines accesses lexical variables declared in its
surrounding scope.
This problem can usually be solved by making the inner subroutine anonymous, using the
"sub {}" syntax. When inner anonymous subs that reference lexical subroutines in
outer subroutines are created, they are automatically rebound to the current values of
such lexical subs.
Substitution loop
(P) The substitution was looping infinitely. (Obviously, a substitution shouldn't
iterate more times than there are characters of input, which is what happened.) See
the discussion of substitution in "Regexp Quote-Like Operators" in perlop.
Substitution pattern not terminated
(F) The lexer couldn't find the interior delimiter of an s/// or s{}{} construct.
Remember that bracketing delimiters count nesting level. Missing the leading "$" from
variable $s may cause this error.
Substitution replacement not terminated
(F) The lexer couldn't find the final delimiter of an s/// or s{}{} construct.
Remember that bracketing delimiters count nesting level. Missing the leading "$" from
variable $s may cause this error.
substr outside of string
(W substr)(F) You tried to reference a substr() that pointed outside of a string.
That is, the absolute value of the offset was larger than the length of the string.
See "substr" in perlfunc. This warning is fatal if substr is used in an lvalue
context (as the left hand side of an assignment or as a subroutine argument for
example).
sv_upgrade from type %d down to type %d
(P) Perl tried to force the upgrade of an SV to a type which was actually inferior to
its current type.
Switch (?(condition)... contains too many branches in regex; marked by <-- HERE in m/%s/
(F) A (?(condition)if-clause|else-clause) construct can have at most two branches (the
if-clause and the else-clause). If you want one or both to contain alternation, such
as using "this|that|other", enclose it in clustering parentheses:
(?(condition)(?:this|that|other)|else-clause)
The <-- HERE shows whereabouts in the regular expression the problem was discovered.
See perlre.
Switch condition not recognized in regex; marked by <-- HERE in m/%s/
(F) The condition part of a (?(condition)if-clause|else-clause) construct is not
known. The condition must be one of the following:
(1) (2) ... true if 1st, 2nd, etc., capture matched
(<NAME>) ('NAME') true if named capture matched
(?=...) (?<=...) true if subpattern matches
(?!...) (?<!...) true if subpattern fails to match
(?{ CODE }) true if code returns a true value
(R) true if evaluating inside recursion
(R1) (R2) ... true if directly inside capture group 1, 2, etc.
(R&NAME) true if directly inside named capture
(DEFINE) always false; for defining named subpatterns
The <-- HERE shows whereabouts in the regular expression the problem was discovered.
See perlre.
Switch (?(condition)... not terminated in regex; marked by <-- HERE in m/%s/
(F) You omitted to close a (?(condition)...) block somewhere in the pattern. Add a
closing parenthesis in the appropriate position. See perlre.
switching effective %s is not implemented
(F) While under the "use filetest" pragma, we cannot switch the real and effective
uids or gids.
syntax error
(F) Probably means you had a syntax error. Common reasons include:
A keyword is misspelled.
A semicolon is missing.
A comma is missing.
An opening or closing parenthesis is missing.
An opening or closing brace is missing.
A closing quote is missing.
Often there will be another error message associated with the syntax error giving more
information. (Sometimes it helps to turn on -w.) The error message itself often
tells you where it was in the line when it decided to give up. Sometimes the actual
error is several tokens before this, because Perl is good at understanding random
input. Occasionally the line number may be misleading, and once in a blue moon the
only way to figure out what's triggering the error is to call "perl -c" repeatedly,
chopping away half the program each time to see if the error went away. Sort of the
cybernetic version of 20 questions.
syntax error at line %d: '%s' unexpected
(A) You've accidentally run your script through the Bourne shell instead of Perl.
Check the #! line, or manually feed your script into Perl yourself.
syntax error in file %s at line %d, next 2 tokens "%s"
(F) This error is likely to occur if you run a perl5 script through a perl4
interpreter, especially if the next 2 tokens are "use strict" or "my $var" or "our
$var".
Syntax error in (?[...]) in regex; marked by <-- HERE in m/%s/
(F) Perl could not figure out what you meant inside this construct; this notifies you
that it is giving up trying.
%s syntax OK
(F) The final summary message when a "perl -c" succeeds.
sysread() on closed filehandle %s
(W closed) You tried to read from a closed filehandle.
sysread() on unopened filehandle %s
(W unopened) You tried to read from a filehandle that was never opened.
System V %s is not implemented on this machine
(F) You tried to do something with a function beginning with "sem", "shm", or "msg"
but that System V IPC is not implemented in your machine. In some machines the
functionality can exist but be unconfigured. Consult your system support.
syswrite() on closed filehandle %s
(W closed) The filehandle you're writing to got itself closed sometime before now.
Check your control flow.
"-T" and "-B" not implemented on filehandles
(F) Perl can't peek at the stdio buffer of filehandles when it doesn't know about your
kind of stdio. You'll have to use a filename instead.
Target of goto is too deeply nested
(F) You tried to use "goto" to reach a label that was too deeply nested for Perl to
reach. Perl is doing you a favor by refusing.
telldir() attempted on invalid dirhandle %s
(W io) The dirhandle you tried to telldir() is either closed or not really a
dirhandle. Check your control flow.
tell() on unopened filehandle
(W unopened) You tried to use the tell() function on a filehandle that was either
never opened or has since been closed.
The crypt() function is unimplemented due to excessive paranoia.
(F) Configure couldn't find the crypt() function on your machine, probably because
your vendor didn't supply it, probably because they think the U.S. Government thinks
it's a secret, or at least that they will continue to pretend that it is. And if you
quote me on that, I will deny it.
The experimental declared_refs feature is not enabled
(F) To declare references to variables, as in "my \%x", you must first enable the
feature:
no warnings "experimental::declared_refs";
use feature "declared_refs";
The %s function is unimplemented
(F) The function indicated isn't implemented on this architecture, according to the
probings of Configure.
The private_use feature is experimental
(S experimental::private_use) This feature is actually a hook for future use.
The stat preceding %s wasn't an lstat
(F) It makes no sense to test the current stat buffer for symbolic linkhood if the
last stat that wrote to the stat buffer already went past the symlink to get to the
real file. Use an actual filename instead.
The Unicode property wildcards feature is experimental
(S experimental::uniprop_wildcards) This feature is experimental and its behavior may
in any future release of perl. See "Wildcards in Property Values" in perlunicode.
The 'unique' attribute may only be applied to 'our' variables
(F) This attribute was never supported on "my" or "sub" declarations.
This Perl can't reset CRTL environ elements (%s)
This Perl can't set CRTL environ elements (%s=%s)
(W internal) Warnings peculiar to VMS. You tried to change or delete an element of
the CRTL's internal environ array, but your copy of Perl wasn't built with a CRTL that
contained the setenv() function. You'll need to rebuild Perl with a CRTL that does,
or redefine PERL_ENV_TABLES (see perlvms) so that the environ array isn't the target
of the change to %ENV which produced the warning.
This Perl has not been built with support for randomized hash key traversal but something
called Perl_hv_rand_set().
(F) Something has attempted to use an internal API call which depends on Perl being
compiled with the default support for randomized hash key traversal, but this Perl has
been compiled without it. You should report this warning to the relevant upstream
party, or recompile perl with default options.
This use of my() in false conditional is no longer allowed
(F) You used a declaration similar to "my $x if 0". There has been a long-standing
bug in Perl that causes a lexical variable not to be cleared at scope exit when its
declaration includes a false conditional. Some people have exploited this bug to
achieve a kind of static variable. Since we intend to fix this bug, we don't want
people relying on this behavior. You can achieve a similar static effect by declaring
the variable in a separate block outside the function, eg
sub f { my $x if 0; return $x++ }
becomes
{ my $x; sub f { return $x++ } }
Beginning with perl 5.10.0, you can also use "state" variables to have lexicals that
are initialized only once (see feature):
sub f { state $x; return $x++ }
This use of my() in a false conditional was deprecated beginning in Perl 5.10 and
became a fatal error in Perl 5.30.
Timeout waiting for another thread to define \p{%s}
(F) The first time a user-defined property ("User-Defined Character Properties" in
perlunicode) is used, its definition is looked up and converted into an internal form
for more efficient handling in subsequent uses. There could be a race if two or more
threads tried to do this processing nearly simultaneously. Instead, a critical
section is created around this task, locking out all but one thread from doing it.
This message indicates that the thread that is doing the conversion is taking an
unexpectedly long time. The timeout exists solely to prevent deadlock; it's long
enough that the system was likely thrashing and about to crash. There is no real
remedy but rebooting.
times not implemented
(F) Your version of the C library apparently doesn't do times(). I suspect you're not
running on Unix.
"-T" is on the #! line, it must also be used on the command line
(X) The #! line (or local equivalent) in a Perl script contains the -T option (or the
-t option), but Perl was not invoked with -T in its command line. This is an error
because, by the time Perl discovers a -T in a script, it's too late to properly taint
everything from the environment. So Perl gives up.
If the Perl script is being executed as a command using the #! mechanism (or its
local equivalent), this error can usually be fixed by editing the #! line so that the
-%c option is a part of Perl's first argument: e.g. change "perl -n -%c" to "perl -%c
-n".
If the Perl script is being executed as "perl scriptname", then the -%c option must
appear on the command line: "perl -%c scriptname".
To%s: illegal mapping '%s'
(F) You tried to define a customized To-mapping for lc(), lcfirst, uc(), or ucfirst()
(or their string-inlined versions), but you specified an illegal mapping. See "User-
Defined Character Properties" in perlunicode.
Too deeply nested ()-groups
(F) Your template contains ()-groups with a ridiculously deep nesting level.
Too few args to syscall
(F) There has to be at least one argument to syscall() to specify the system call to
call, silly dilly.
Too few arguments for subroutine '%s' (got %d; expected %d)
(F) A subroutine using a signature fewer arguments than required by the signature.
The caller of the subroutine is presumably at fault.
The message attempts to include the name of the called subroutine. If the subroutine
has been aliased, the subroutine's original name will be shown, regardless of what
name the caller used. It will also indicate the number of arguments given and the
number expected.
Too few arguments for subroutine '%s' (got %d; expected at least %d)
Similar to the previous message but for subroutines that accept a variable number of
arguments.
Too late for "-%s" option
(X) The #! line (or local equivalent) in a Perl script contains the -M, -m or -C
option.
In the case of -M and -m, this is an error because those options are not intended for
use inside scripts. Use the "use" pragma instead.
The -C option only works if it is specified on the command line as well (with the same
sequence of letters or numbers following). Either specify this option on the command
line, or, if your system supports it, make your script executable and run it directly
instead of passing it to perl.
Too late to run %s block
(W void) A CHECK or INIT block is being defined during run time proper, when the
opportunity to run them has already passed. Perhaps you are loading a file with
"require" or "do" when you should be using "use" instead. Or perhaps you should put
the "require" or "do" inside a BEGIN block.
Too many args to syscall
(F) Perl supports a maximum of only 14 args to syscall().
Too many arguments for %s
(F) The function requires fewer arguments than you specified.
Too many arguments for subroutine '%s' (got %d; expected %d)
(F) A subroutine using a signature received more arguments than permitted by the
signature. The caller of the subroutine is presumably at fault.
The message attempts to include the name of the called subroutine. If the subroutine
has been aliased, the subroutine's original name will be shown, regardless of what
name the caller used. It will also indicate the number of arguments given and the
number expected.
Too many arguments for subroutine '%s' (got %d; expected at most %d)
Similar to the previous message but for subroutines that accept a variable number of
arguments.
Too many nested open parens in regex; marked by <-- HERE in m/%s/
(F) You have exceeded the number of open "(" parentheses that haven't been matched by
corresponding closing ones. This limit prevents eating up too much memory. It is
initially set to 1000, but may be changed by setting "${^RE_COMPILE_RECURSION_LIMIT}"
to some other value. This may need to be done in a BEGIN block before the regular
expression pattern is compiled.
Too many nested BEGIN blocks, maximum of %d allowed
(F) You have executed code that nests too many BEGIN blocks inside of each other,
either explicitly as BEGIN{} or implicitly as use statements. This limit defaults to
a rather high number which should not be exceeded in normal circumstances, and
triggering likely indicates something is very wrong in your code. For instance
infinite recursion of eval and BEGIN blocks is known to trigger this error.
If you know that you have good reason to exceed the limit you can change it by setting
"${^MAX_NESTED_EVAL_BEGIN_BLOCKS}" to a different value from the default of 1000.
Too many capture groups (limit is %d) in regex m/%s/
(F) You have too many capture groups in your regex pattern. You need to rework your
pattern to use less capture groups.
Too many )'s
(A) You've accidentally run your script through csh instead of Perl. Check the #!
line, or manually feed your script into Perl yourself.
Too many ('s
(A) You've accidentally run your script through csh instead of Perl. Check the #!
line, or manually feed your script into Perl yourself.
Trailing \ in regex m/%s/
(F) The regular expression ends with an unbackslashed backslash. Backslash it. See
perlre.
Transliteration pattern not terminated
(F) The lexer couldn't find the interior delimiter of a tr/// or tr[][] or y/// or
y[][] construct. Missing the leading "$" from variables $tr or $y may cause this
error.
Transliteration replacement not terminated
(F) The lexer couldn't find the final delimiter of a tr///, tr[][], y/// or y[][]
construct.
Treating %s::INIT block as BEGIN block as workaround
(S) A package is using an old version of "Module::Install::DSL" to install, which
makes unsafe assumptions about when INIT blocks will be called. Because
"Module::Install::DSL" is used to install other modules and is difficult to upgrade we
have a special workaround in place to deal with this. Unless you are a maintainer of
an affected module you can ignore this warning. We emit it only as a sanity check.
'%s' trapped by operation mask
(F) You tried to use an operator from a Safe compartment in which it's disallowed.
See Safe.
truncate not implemented
(F) Your machine doesn't implement a file truncation mechanism that Configure knows
about.
try/catch/finally is experimental
(S experimental::try) This warning is emitted if you use the "try" and "catch" syntax
with a "finally" block. This syntax is currently experimental and its behaviour may
change in future releases of Perl.
Type of arg %d to &CORE::%s must be %s
(F) The subroutine in question in the CORE package requires its argument to be a hard
reference to data of the specified type. Overloading is ignored, so a reference to an
object that is not the specified type, but nonetheless has overloading to handle it,
will still not be accepted.
Type of arg %d to %s must be %s (not %s)
(F) This function requires the argument in that position to be of a certain type.
Arrays must be @NAME or "@{EXPR}". Hashes must be %NAME or "%{EXPR}". No implicit
dereferencing is allowed--use the {EXPR} forms as an explicit dereference. See
perlref.
umask not implemented
(F) Your machine doesn't implement the umask function and you tried to use it to
restrict permissions for yourself (EXPR & 0700).
UNIVERSAL does not export anything
(F) You asked UNIVERSAL to export something, but UNIVERSAL is the base class for all
classes and contains no exportable symbols.
Unbalanced context: %d more PUSHes than POPs
(S internal) The exit code detected an internal inconsistency in how many execution
contexts were entered and left.
Unbalanced saves: %d more saves than restores
(S internal) The exit code detected an internal inconsistency in how many values were
temporarily localized.
Unbalanced scopes: %d more ENTERs than LEAVEs
(S internal) The exit code detected an internal inconsistency in how many blocks were
entered and left.
Unbalanced string table refcount: (%d) for "%s"
(S internal) On exit, Perl found some strings remaining in the shared string table
used for copy on write and for hash keys. The entries should have been freed, so this
indicates a bug somewhere.
Unbalanced tmps: %d more allocs than frees
(S internal) The exit code detected an internal inconsistency in how many mortal
scalars were allocated and freed.
Undefined format "%s" called
(F) The format indicated doesn't seem to exist. Perhaps it's really in another
package? See perlform.
Undefined sort subroutine "%s" called
(F) The sort comparison routine specified doesn't seem to exist. Perhaps it's in a
different package? See "sort" in perlfunc.
Undefined subroutine &%s called
(F) The subroutine indicated hasn't been defined, or if it was, it has since been
undefined.
Undefined subroutine called
(F) The anonymous subroutine you're trying to call hasn't been defined, or if it was,
it has since been undefined.
Undefined subroutine in sort
(F) The sort comparison routine specified is declared but doesn't seem to have been
defined yet. See "sort" in perlfunc.
Undefined top format "%s" called
(F) The format indicated doesn't seem to exist. Perhaps it's really in another
package? See perlform.
Undefined value assigned to typeglob
(W misc) An undefined value was assigned to a typeglob, a la "*foo = undef". This
does nothing. It's possible that you really mean "undef *foo".
%s: Undefined variable
(A) You've accidentally run your script through csh instead of Perl. Check the #!
line, or manually feed your script into Perl yourself.
Unescaped left brace in regex is illegal here in regex; marked by <-- HERE in m/%s/
(F) The simple rule to remember, if you want to match a literal "{" character (U+007B
"LEFT CURLY BRACKET") in a regular expression pattern, is to escape each literal
instance of it in some way. Generally easiest is to precede it with a backslash, like
"\{" or enclose it in square brackets ("[{]"). If the pattern delimiters are also
braces, any matching right brace ("}") should also be escaped to avoid confusing the
parser, for example,
qr{abc\{def\}ghi}
Forcing literal "{" characters to be escaped enables the Perl language to be extended
in various ways in future releases. To avoid needlessly breaking existing code, the
restriction is not enforced in contexts where there are unlikely to ever be extensions
that could conflict with the use there of "{" as a literal. Those that are not
potentially ambiguous do not warn; those that are do raise a non-deprecation warning.
The contexts where no warnings or errors are raised are:
• as the first character in a pattern, or following "^" indicating to anchor the
match to the beginning of a line.
• as the first character following a "|" indicating alternation.
• as the first character in a parenthesized grouping like
/foo({bar)/
/foo(?:{bar)/
• as the first character following a quantifier
/\s*{/
Unescaped left brace in regex is passed through in regex; marked by <-- HERE in m/%s/
(W regexp) The simple rule to remember, if you want to match a literal "{" character
(U+007B "LEFT CURLY BRACKET") in a regular expression pattern, is to escape each
literal instance of it in some way. Generally easiest is to precede it with a
backslash, like "\{" or enclose it in square brackets ("[{]"). If the pattern
delimiters are also braces, any matching right brace ("}") should also be escaped to
avoid confusing the parser, for example,
qr{abc\{def\}ghi}
Forcing literal "{" characters to be escaped enables the Perl language to be extended
in various ways in future releases. To avoid needlessly breaking existing code, the
restriction is not enforced in contexts where there are unlikely to ever be extensions
that could conflict with the use there of "{" as a literal. Those that are not
potentially ambiguous do not warn; those that are raise this warning. This makes sure
that an inadvertent typo doesn't silently cause the pattern to compile to something
unintended.
The contexts where no warnings or errors are raised are:
• as the first character in a pattern, or following "^" indicating to anchor the
match to the beginning of a line.
• as the first character following a "|" indicating alternation.
• as the first character in a parenthesized grouping like
/foo({bar)/
/foo(?:{bar)/
• as the first character following a quantifier
/\s*{/
Unescaped literal '%c' in regex; marked by <-- HERE in m/%s/
(W regexp) (only under "use re 'strict'")
Within the scope of "use re 'strict'" in a regular expression pattern, you included an
unescaped "}" or "]" which was interpreted literally. These two characters are
sometimes metacharacters, and sometimes literals, depending on what precedes them in
the pattern. This is unlike the similar ")" which is always a metacharacter unless
escaped.
This action at a distance, perhaps a large distance, can lead to Perl silently
misinterpreting what you meant, so when you specify that you want extra checking by
"use re 'strict'", this warning is generated. If you meant the character as a
literal, simply confirm that to Perl by preceding the character with a backslash, or
make it into a bracketed character class (like "[}]"). If you meant it as closing a
corresponding "[" or "{", you'll need to look back through the pattern to find out why
that isn't happening.
unexec of %s into %s failed!
(F) The unexec() routine failed for some reason. See your local FSF representative,
who probably put it there in the first place.
Unexpected binary operator '%c' with no preceding operand in regex; marked by <-- HERE in
m/%s/
(F) You had something like this:
(?[ | \p{Digit} ])
where the "|" is a binary operator with an operand on the right, but no operand on the
left.
Unexpected character in regex; marked by <-- HERE in m/%s/
(F) You had something like this:
(?[ z ])
Within "(?[ ])", no literal characters are allowed unless they are within an inner
pair of square brackets, like
(?[ [ z ] ])
Another possibility is that you forgot a backslash. Perl isn't smart enough to figure
out what you really meant.
Unexpected characters while parsing class :isa attribute: %s
(F) You tried to specify something other than a single class name with an optional
trailing verison number as the value for a "class" ":isa" attribute. This confused
the parser.
Unexpected exit %u
(S) exit() was called or the script otherwise finished gracefully when
"PERL_EXIT_WARN" was set in "PL_exit_flags".
Unexpected exit failure %d
(S) An uncaught die() was called when "PERL_EXIT_WARN" was set in "PL_exit_flags".
Unexpected ')' in regex; marked by <-- HERE in m/%s/
(F) You had something like this:
(?[ ( \p{Digit} + ) ])
The ")" is out-of-place. Something apparently was supposed to be combined with the
digits, or the "+" shouldn't be there, or something like that. Perl can't figure out
what was intended.
Unexpected ']' with no following ')' in (?[... in regex; marked by <-- HERE in m/%s/
(F) While parsing an extended character class a ']' character was encountered at a
point in the definition where the only legal use of ']' is to close the character
class definition as part of a '])', you may have forgotten the close paren, or
otherwise confused the parser.
Unexpected '(' with no preceding operator in regex; marked by <-- HERE in m/%s/
(F) You had something like this:
(?[ \p{Digit} ( \p{Lao} + \p{Thai} ) ])
There should be an operator before the "(", as there's no indication as to how the
digits are to be combined with the characters in the Lao and Thai scripts.
Unicode non-character U+%X is not recommended for open interchange
(S nonchar) Certain codepoints, such as U+FFFE and U+FFFF, are defined by the Unicode
standard to be non-characters. Those are legal codepoints, but are reserved for
internal use; so, applications shouldn't attempt to exchange them. An application may
not be expecting any of these characters at all, and receiving them may lead to bugs.
If you know what you are doing you can turn off this warning by "no warnings
'nonchar';".
This is not really a "severe" error, but it is supposed to be raised by default even
if warnings are not enabled, and currently the only way to do that in Perl is to mark
it as serious.
Unicode property wildcard not terminated
(F) A Unicode property wildcard looks like a delimited regular expression pattern (all
within the braces of the enclosing "\p{...}". The closing delimtter to match the
opening one was not found. If the opening one is escaped by preceding it with a
backslash, the closing one must also be so escaped.
Unicode string properties are not implemented in (?[...]) in regex; marked by <-- HERE in
m/%s/
(F) A Unicode string property is one which expands to a sequence of multiple
characters. An example is "\p{name=KATAKANA LETTER AINU P}", which consists of the
sequence "\N{KATAKANA LETTER SMALL H}" followed by "\N{COMBINING KATAKANA-HIRAGANA
SEMI-VOICED SOUND MARK}". Extended character classes, "(?[...])" currently cannot
handle these.
Unicode surrogate U+%X is illegal in UTF-8
(S surrogate) You had a UTF-16 surrogate in a context where they are not considered
acceptable. These code points, between U+D800 and U+DFFF (inclusive), are used by
Unicode only for UTF-16. However, Perl internally allows all unsigned integer code
points (up to the size limit available on your platform), including surrogates. But
these can cause problems when being input or output, which is likely where this
message came from. If you really really know what you are doing you can turn off this
warning by "no warnings 'surrogate';".
Unimplemented
(F) In Perl 5.12 and above, you have executed an ellipsis statement. This is a bare
"...;", meant to be used to allow you to outline code that is to be written, but is
not complete, similar to the following:
sub not_done_yet {
my($self, $arg1, $arg2) = @_;
...
}
If not_done_yet() is called, Perl will die with an "Unimplemented" error at the line
containing "...".
Unknown charname '%s'
(F) The name you used inside "\N{}" is unknown to Perl. Check the spelling. You can
say "use charnames ":loose"" to not have to be so precise about spaces, hyphens, and
capitalization on standard Unicode names. (Any custom aliases that have been created
must be specified exactly, regardless of whether ":loose" is used or not.) This error
may also happen if the "\N{}" is not in the scope of the corresponding
"use charnames".
Unknown '(*...)' construct '%s' in regex; marked by <-- HERE in m/%s/
(F) The "(*" was followed by something that the regular expression compiler does not
recognize. Check your spelling.
Unknown error
(P) Perl was about to print an error message in $@, but the $@ variable did not exist,
even after an attempt to create it.
Unknown locale category %d
Unknown locale category %d; can't set it to %s
(W locale) You used a locale category that perl doesn't recognize, so it cannot carry
out your request. Check that you are using a valid category. If so, see "Multi-
threaded" in perllocale for advice on reporting this as a bug, and for modifying perl
locally to accommodate your needs.
Unknown open() mode '%s'
(F) The second argument of 3-argument open() is not among the list of valid modes:
"<", ">", ">>", "+<", "+>", "+>>", "-|", "|-", "<&", ">&".
Unknown PerlIO layer "%s"
(W layer) An attempt was made to push an unknown layer onto the Perl I/O system.
(Layers take care of transforming data between external and internal representations.)
Note that some layers, such as "mmap", are not supported in all environments. If your
program didn't explicitly request the failing operation, it may be the result of the
value of the environment variable PERLIO.
Unknown process %x sent message to prime_env_iter: %s
(P) An error peculiar to VMS. Perl was reading values for %ENV before iterating over
it, and someone else stuck a message in the stream of data Perl expected. Someone's
very confused, or perhaps trying to subvert Perl's population of %ENV for nefarious
purposes.
Unknown regexp modifier "/%s"
(F) Alphanumerics immediately following the closing delimiter of a regular expression
pattern are interpreted by Perl as modifier flags for the regex. One of the ones you
specified is invalid. One way this can happen is if you didn't put in white space
between the end of the regex and a following alphanumeric operator:
if ($x =~ /foo/and $bar == 3) { ... }
The "a" is a valid modifier flag, but the "n" is not, and raises this error. Likely
what was meant instead was:
if ($x =~ /foo/ and $bar == 3) { ... }
Unknown "re" subpragma '%s' (known ones are: %s)
(W) You tried to use an unknown subpragma of the "re" pragma.
Unknown switch condition (?(...)) in regex; marked by <-- HERE in m/%s/
(F) The condition part of a (?(condition)if-clause|else-clause) construct is not
known. The condition must be one of the following:
(1) (2) ... true if 1st, 2nd, etc., capture matched
(<NAME>) ('NAME') true if named capture matched
(?=...) (?<=...) true if subpattern matches
(*pla:...) (*plb:...) true if subpattern matches; also
(*positive_lookahead:...)
(*positive_lookbehind:...)
(*nla:...) (*nlb:...) true if subpattern fails to match; also
(*negative_lookahead:...)
(*negative_lookbehind:...)
(?{ CODE }) true if code returns a true value
(R) true if evaluating inside recursion
(R1) (R2) ... true if directly inside capture group 1, 2,
etc.
(R&NAME) true if directly inside named capture
(DEFINE) always false; for defining named subpatterns
The <-- HERE shows whereabouts in the regular expression the problem was discovered.
See perlre.
Unknown Unicode option letter '%c'
(F) You specified an unknown Unicode option. See perlrun documentation of the "-C"
switch for the list of known options.
Unknown Unicode option value %d
(F) You specified an unknown Unicode option. See perlrun documentation of the "-C"
switch for the list of known options.
Unknown user-defined property name \p{%s}
(F) You specified to use a property within the "\p{...}" which was a syntactically
valid user-defined property, but no definition was found for it by the time one was
required to proceed. Check your spelling. See "User-Defined Character Properties" in
perlunicode.
Unknown verb pattern '%s' in regex; marked by <-- HERE in m/%s/
(F) You either made a typo or have incorrectly put a "*" quantifier after an open
brace in your pattern. Check the pattern and review perlre for details on legal verb
patterns.
Unknown warnings category '%s'
(F) An error issued by the "warnings" pragma. You specified a warnings category that
is unknown to perl at this point.
Note that if you want to enable a warnings category registered by a module (e.g. "use
warnings 'File::Find'"), you must have loaded this module first.
Unmatched [ in regex; marked by <-- HERE in m/%s/
(F) The brackets around a character class must match. If you wish to include a
closing bracket in a character class, backslash it or put it first. The <-- HERE
shows whereabouts in the regular expression the problem was discovered. See perlre.
Unmatched ( in regex; marked by <-- HERE in m/%s/
Unmatched ) in regex; marked by <-- HERE in m/%s/
(F) Unbackslashed parentheses must always be balanced in regular expressions. If
you're a vi user, the % key is valuable for finding the matching parenthesis. The
<-- HERE shows whereabouts in the regular expression the problem was discovered. See
perlre.
Unmatched right %s bracket
(F) The lexer counted more closing curly or square brackets than opening ones, so
you're probably missing a matching opening bracket. As a general rule, you'll find
the missing one (so to speak) near the place you were last editing.
Unquoted string "%s" may clash with future reserved word
(W reserved) You used a bareword that might someday be claimed as a reserved word.
It's best to put such a word in quotes, or capitalize it somehow, or insert an
underbar into it. You might also declare it as a subroutine.
Unrecognized character %s; marked by <-- HERE after %s near column %d
(F) The Perl parser has no idea what to do with the specified character in your Perl
script (or eval) near the specified column. Perhaps you tried to run a compressed
script, a binary program, or a directory as a Perl program.
Unrecognized class attribute %s
(F) You attempted to add a named attribute to a "class" definition, but perl does not
recognise the name of the requested attribute.
Unrecognized escape \%c in character class in regex; marked by <-- HERE in m/%s/
(F) You used a backslash-character combination which is not recognized by Perl inside
character classes. This is a fatal error when the character class is used within "(?[
])".
Unrecognized escape \%c in character class passed through in regex; marked by <-- HERE in
m/%s/
(W regexp) You used a backslash-character combination which is not recognized by Perl
inside character classes. The character was understood literally, but this may change
in a future version of Perl. The <-- HERE shows whereabouts in the regular expression
the escape was discovered.
Unrecognized escape \%c passed through
(W misc) You used a backslash-character combination which is not recognized by Perl.
The character was understood literally, but this may change in a future version of
Perl.
Unrecognized escape \%s passed through in regex; marked by <-- HERE in m/%s/
(W regexp) You used a backslash-character combination which is not recognized by Perl.
The character(s) were understood literally, but this may change in a future version of
Perl. The <-- HERE shows whereabouts in the regular expression the escape was
discovered.
Unrecognized field attribute %s
(F) You attempted to add a named attribute to a "field" definition, but perl does not
recognise the name of the requested attribute.
Unrecognised parameters for "%s" constructor: %s
(F) You called new on a class but supplied a parameter name that didn't match a class
field name.
Unrecognized signal name "%s"
(F) You specified a signal name to the kill() function that was not recognized. Say
"kill -l" in your shell to see the valid signal names on your system.
Unrecognized switch: -%s (-h will show valid options)
(F) You specified an illegal option to Perl. Don't do that. (If you think you didn't
do that, check the #! line to see if it's supplying the bad switch on your behalf.)
Unsuccessful %s on filename containing newline
(W newline) A file operation was attempted on a filename, and that operation failed,
PROBABLY because the filename contained a newline, PROBABLY because you forgot to
chomp() it off. See "chomp" in perlfunc.
Unsupported directory function "%s" called
(F) Your machine doesn't support opendir() and readdir().
Unsupported function %s
(F) This machine doesn't implement the indicated function, apparently. At least,
Configure doesn't think so.
Unsupported function fork
(F) Your version of executable does not support forking.
Note that under some systems, like OS/2, there may be different flavors of Perl
executables, some of which may support fork, some not. Try changing the name you call
Perl by to "perl_", "perl__", and so on.
Unsupported script encoding %s
(F) Your program file begins with a Unicode Byte Order Mark (BOM) which declares it to
be in a Unicode encoding that Perl cannot read.
Unsupported socket function "%s" called
(F) Your machine doesn't support the Berkeley socket mechanism, or at least that's
what Configure thought.
Unterminated '(*...' argument in regex; marked by <-- HERE in m/%s/
(F) You used a pattern of the form "(*...:...)" but did not terminate the pattern with
a ")". Fix the pattern and retry.
Unterminated attribute list
(F) The lexer found something other than a simple identifier at the start of an
attribute, and it wasn't a semicolon or the start of a block. Perhaps you terminated
the parameter list of the previous attribute too soon. See attributes.
Unterminated attribute parameter in attribute list
(F) The lexer saw an opening (left) parenthesis character while parsing an attribute
list, but the matching closing (right) parenthesis character was not found. You may
need to add (or remove) a backslash character to get your parentheses to balance. See
attributes.
Unterminated compressed integer
(F) An argument to unpack("w",...) was incompatible with the BER compressed integer
format and could not be converted to an integer. See "pack" in perlfunc.
Unterminated '(*...' construct in regex; marked by <-- HERE in m/%s/
(F) You used a pattern of the form "(*...)" but did not terminate the pattern with a
")". Fix the pattern and retry.
Unterminated delimiter for here document
(F) This message occurs when a here document label has an initial quotation mark but
the final quotation mark is missing. Perhaps you wrote:
<<"foo
instead of:
<<"foo"
Unterminated \g... pattern in regex; marked by <-- HERE in m/%s/
Unterminated \g{...} pattern in regex; marked by <-- HERE in m/%s/
(F) In a regular expression, you had a "\g" that wasn't followed by a proper group
reference. In the case of "\g{", the closing brace is missing; otherwise the "\g"
must be followed by an integer. Fix the pattern and retry.
Unterminated <> operator
(F) The lexer saw a left angle bracket in a place where it was expecting a term, so
it's looking for the corresponding right angle bracket, and not finding it. Chances
are you left some needed parentheses out earlier in the line, and you really meant a
"less than".
Unterminated verb pattern argument in regex; marked by <-- HERE in m/%s/
(F) You used a pattern of the form "(*VERB:ARG)" but did not terminate the pattern
with a ")". Fix the pattern and retry.
Unterminated verb pattern in regex; marked by <-- HERE in m/%s/
(F) You used a pattern of the form "(*VERB)" but did not terminate the pattern with a
")". Fix the pattern and retry.
untie attempted while %d inner references still exist
(W untie) A copy of the object returned from "tie" (or "tied") was still valid when
"untie" was called.
Usage: POSIX::%s(%s)
(F) You called a POSIX function with incorrect arguments. See "FUNCTIONS" in POSIX
for more information.
Usage: Win32::%s(%s)
(F) You called a Win32 function with incorrect arguments. See Win32 for more
information.
$[ used in %s (did you mean $] ?)
(W syntax) You used $[ in a comparison, such as:
if ($[ > 5.006) {
...
}
You probably meant to use $] instead. $[ is the base for indexing arrays. $] is the
Perl version number in decimal.
Use "%s" instead of "%s"
(F) The second listed construct is no longer legal. Use the first one instead.
Useless assignment to a temporary
(W misc) You assigned to an lvalue subroutine, but what the subroutine returned was a
temporary scalar about to be discarded, so the assignment had no effect.
Useless (?-%s) - don't use /%s modifier in regex; marked by <-- HERE in m/%s/
(W regexp) You have used an internal modifier such as (?-o) that has no meaning unless
removed from the entire regexp:
if ($string =~ /(?-o)$pattern/o) { ... }
must be written as
if ($string =~ /$pattern/) { ... }
The <-- HERE shows whereabouts in the regular expression the problem was discovered.
See perlre.
Useless localization of %s
(W syntax) The localization of lvalues such as local($x=10) is legal, but in fact the
local() currently has no effect. This may change at some point in the future, but in
the meantime such code is discouraged.
Useless (?%s) - use /%s modifier in regex; marked by <-- HERE in m/%s/
(W regexp) You have used an internal modifier such as (?o) that has no meaning unless
applied to the entire regexp:
if ($string =~ /(?o)$pattern/) { ... }
must be written as
if ($string =~ /$pattern/o) { ... }
The <-- HERE shows whereabouts in the regular expression the problem was discovered.
See perlre.
Useless use of attribute "const"
(W misc) The "const" attribute has no effect except on anonymous closure prototypes.
You applied it to a subroutine via attributes.pm. This is only useful inside an
attribute handler for an anonymous subroutine.
Useless use of /d modifier in transliteration operator
(W misc) You have used the /d modifier where the searchlist has the same length as the
replacelist. See perlop for more information about the /d modifier.
Useless use of \E
(W misc) You have a \E in a double-quotish string without a "\U", "\L" or "\Q"
preceding it.
Useless use of greediness modifier '%c' in regex; marked by <-- HERE in m/%s/
(W regexp) You specified something like these:
qr/a{3}?/
qr/b{1,1}+/
The "?" and "+" don't have any effect, as they modify whether to match more or fewer
when there is a choice, and by specifying to match exactly a given number, there is no
room left for a choice.
Useless use of %s in scalar context
(W scalar) You did something whose only interesting return value is a list without a
side effect in scalar context, which does not accept a list.
For example
my $x = sort @y;
This is not very useful, and perl currently optimizes this away.
Useless use of %s in void context
(W void) You did something without a side effect in a context that does nothing with
the return value, such as a statement that doesn't return a value from a block, or the
left side of a scalar comma operator. Very often this points not to stupidity on your
part, but a failure of Perl to parse your program the way you thought it would. For
example, you'd get this if you mixed up your C precedence with Python precedence and
said
$one, $two = 1, 2;
when you meant to say
($one, $two) = (1, 2);
Another common error is to use ordinary parentheses to construct a list reference when
you should be using square or curly brackets, for example, if you say
$array = (1,2);
when you should have said
$array = [1,2];
The square brackets explicitly turn a list value into a scalar value, while
parentheses do not. So when a parenthesized list is evaluated in a scalar context,
the comma is treated like C's comma operator, which throws away the left argument,
which is not what you want. See perlref for more on this.
This warning will not be issued for numerical constants equal to 0 or 1 since they are
often used in statements like
1 while sub_with_side_effects();
String constants that would normally evaluate to 0 or 1 are warned about.
Useless use of (?-p) in regex; marked by <-- HERE in m/%s/
(W regexp) The "p" modifier cannot be turned off once set. Trying to do so is futile.
Useless use of "re" pragma
(W) You did "use re;" without any arguments. That isn't very useful.
Useless use of %s with no values
(W syntax) You used the push() or unshift() function with no arguments apart from the
array, like push(@x) or unshift(@foo). That won't usually have any effect on the
array, so is completely useless. It's possible in principle that push(@tied_array)
could have some effect if the array is tied to a class which implements a PUSH method.
If so, you can write it as "push(@tied_array,())" to avoid this warning.
"use" not allowed in expression
(F) The "use" keyword is recognized and executed at compile time, and returns no
useful value. See perlmod.
Use of @_ in %s with signatured subroutine is experimental
(S experimental::args_array_with_signatures) An expression involving the @_ arguments
array was found in a subroutine that uses a signature. This is experimental because
the interaction between the arguments array and parameter handling via signatures is
not guaranteed to remain stable in any future version of Perl, and such code should be
avoided.
Use of bare << to mean <<"" is forbidden
(F) You are now required to use the explicitly quoted form if you wish to use an empty
line as the terminator of the here-document.
Use of a bare terminator was deprecated in Perl 5.000, and is a fatal error as of Perl
5.28.
Use of /c modifier is meaningless in s///
(W regexp) You used the /c modifier in a substitution. The /c modifier is not
presently meaningful in substitutions.
Use of /c modifier is meaningless without /g
(W regexp) You used the /c modifier with a regex operand, but didn't use the /g
modifier. Currently, /c is meaningful only when /g is used. (This may change in the
future.)
Use of code point 0x%s is not allowed; the permissible max is 0x%X
Use of code point 0x%s is not allowed; the permissible max is 0x%X in regex; marked by <--
HERE in m/%s/
(F) You used a code point that is not allowed, because it is too large. Unicode only
allows code points up to 0x10FFFF, but Perl allows much larger ones. Earlier versions
of Perl allowed code points above IV_MAX (0x7FFFFFF on 32-bit platforms,
0x7FFFFFFFFFFFFFFF on 64-bit platforms), however, this could possibly break the perl
interpreter in some constructs, including causing it to hang in a few cases.
If your code is to run on various platforms, keep in mind that the upper limit depends
on the platform. It is much larger on 64-bit word sizes than 32-bit ones.
The use of out of range code points was deprecated in Perl 5.24, and became a fatal
error in Perl 5.28.
Use of each() on hash after insertion without resetting hash iterator results in undefined
behavior
(S internal) The behavior of each() after insertion is undefined; it may skip items,
or visit items more than once. Consider using keys() instead of each().
Use of := for an empty attribute list is not allowed
(F) The construction "my $x := 42" used to parse as equivalent to "my $x : = 42"
(applying an empty attribute list to $x). This construct was deprecated in 5.12.0,
and has now been made a syntax error, so ":=" can be reclaimed as a new operator in
the future.
If you need an empty attribute list, for example in a code generator, add a space
before the "=".
Use of %s for non-UTF-8 locale is wrong. Assuming a UTF-8 locale
(W locale) You are matching a regular expression using locale rules, and the
specified construct was encountered. This construct is only valid for UTF-8 locales,
which the current locale isn't. This doesn't make sense. Perl will continue,
assuming a Unicode (UTF-8) locale, but the results are likely to be wrong.
Use of freed value in iteration
(F) Perhaps you modified the iterated array within the loop? This error is typically
caused by code like the following:
@a = (3,4);
@a = () for (1,2,@a);
You are not supposed to modify arrays while they are being iterated over. For speed
and efficiency reasons, Perl internally does not do full reference-counting of
iterated items, hence deleting such an item in the middle of an iteration causes Perl
to see a freed value.
Use of /g modifier is meaningless in split
(W regexp) You used the /g modifier on the pattern for a "split" operator. Since
"split" always tries to match the pattern repeatedly, the "/g" has no effect.
Use of "goto" to jump into a construct is deprecated
(D deprecated::goto_construct) Using "goto" to jump from an outer scope into an inner
scope is deprecated and will be removed completely in Perl 5.42.
This was deprecated in Perl 5.12.
Use of '%s' in \p{} or \P{} is deprecated because: %s
(D deprecated::unicode_property_name) Certain properties are deprecated by Unicode,
and may eventually be removed from the Standard, at which time Perl will follow along.
In the meantime, this message is raised to notify you.
Use of inherited AUTOLOAD for non-method %s::%s() is no longer allowed
(F) As an accidental feature, "AUTOLOAD" subroutines were looked up as methods (using
the @ISA hierarchy), even when the subroutines to be autoloaded were called as plain
functions (e.g. Foo::bar()), not as methods (e.g. "Foo->bar()" or "$obj->bar()").
This was deprecated in Perl 5.004, and was made fatal in Perl 5.28.
Use of %s in printf format not supported
(F) You attempted to use a feature of printf that is accessible from only C. This
usually means there's a better way to do it in Perl.
Use of '%s' is deprecated as a string delimiter
(D deprecated::delimiter_will_be_paired) You used the given character as a starting
delimiter of a string outside the scope of "use feature 'extra_paired_delimiters'".
This character is the mirror image of another Unicode character; within the scope of
that feature, the two are considered a pair for delimitting strings. It is planned to
make that feature the default, at which point this usage would become illegal; hence
this warning.
For now, you may live with this warning, or turn it off, but this code will no longer
compile in a future version of Perl. Or you can turn on
"use feature 'extra_paired_delimiters'" and use the character that is the mirror image
of this one for the closing string delimiter.
Use of '%s' is experimental as a string delimiter
(S experimental::extra_paired_delimiters) This warning is emitted if you use as a
string delimiter one of the non-ASCII mirror image ones enabled by
"use feature 'extra_paired_delimiters'". Simply suppress the warning if you want to
use the feature, but know that in doing so you are taking the risk of using an
experimental feature which may change or be removed in a future Perl version:
Use of %s is not allowed in Unicode property wildcard subpatterns in regex; marked by
<-- HERE in m/%s/
(F) You were using a wildcard subpattern a Unicode property value, and the subpattern
contained something that is illegal. Not all regular expression capabilities are
legal in such subpatterns, and this is one. Rewrite your subppattern to not use the
offending construct. See "Wildcards in Property Values" in perlunicode.
Use of -l on filehandle%s
(W io) A filehandle represents an opened file, and when you opened the file it already
went past any symlink you are presumably trying to look for. The operation returned
"undef". Use a filename instead.
Use of reference "%s" as array index
(W misc) You tried to use a reference as an array index; this probably isn't what you
mean, because references in numerical context tend to be huge numbers, and so usually
indicates programmer error.
If you really do mean it, explicitly numify your reference, like so: $array[0+$ref].
This warning is not given for overloaded objects, however, because you can overload
the numification and stringification operators and then you presumably know what you
are doing.
Use of strings with code points over 0xFF as arguments to %s operator is not allowed
(F) You tried to use one of the string bitwise operators ("&" or "|" or "^" or "~") on
a string containing a code point over 0xFF. The string bitwise operators treat their
operands as strings of bytes, and values beyond 0xFF are nonsensical in this context.
Certain instances became fatal in Perl 5.28; others in perl 5.32.
Use of strings with code points over 0xFF as arguments to vec is forbidden
(F) You tried to use "vec" on a string containing a code point over 0xFF, which is
nonsensical here.
This became fatal in Perl 5.32.
Use of tainted arguments in %s is deprecated
(W taint, deprecated) You have supplied system() or exec() with multiple arguments and
at least one of them is tainted. This used to be allowed but will become a fatal
error in a future version of perl. Untaint your arguments. See perlsec.
Use of unassigned code point or non-standalone grapheme for a delimiter is not allowed
(F) A grapheme is what appears to a native-speaker of a language to be a character.
In Unicode (and hence Perl) a grapheme may actually be several adjacent characters
that together form a complete grapheme. For example, there can be a base character,
like "R" and an accent, like a circumflex "^", that appear when displayed to be a
single character with the circumflex hovering over the "R". Perl currently allows
things like that circumflex to be delimiters of strings, patterns, etc. When
displayed, the circumflex would look like it belongs to the character just to the left
of it. In order to move the language to be able to accept graphemes as delimiters, we
cannot allow the use of delimiters which aren't graphemes by themselves. Also, a
delimiter must already be assigned (or known to be never going to be assigned) to try
to future-proof code, for otherwise code that works today would fail to compile if the
currently unassigned delimiter ends up being something that isn't a stand-alone
grapheme. Because Unicode is never going to assign non-character code points, nor
code points that are above the legal Unicode maximum, those can be delimiters, and
their use is legal.
Use of uninitialized value%s
(W uninitialized) An undefined value was used as if it were already defined. It was
interpreted as a "" or a 0, but maybe it was a mistake. To suppress this warning
assign a defined value to your variables.
To help you figure out what was undefined, perl will try to tell you the name of the
variable (if any) that was undefined. In some cases it cannot do this, so it also
tells you what operation you used the undefined value in. Note, however, that perl
optimizes your program and the operation displayed in the warning may not necessarily
appear literally in your program. For example, "that $foo" is usually optimized into
""that " . $foo", and the warning will refer to the "concatenation (.)" operator, even
though there is no "." in your program.
"use re 'strict'" is experimental
(S experimental::re_strict) The things that are different when a regular expression
pattern is compiled under 'strict' are subject to change in future Perl releases in
incompatible ways. This means that a pattern that compiles today may not in a future
Perl release. This warning is to alert you to that risk.
use VERSION is not permitted while another use VERSION of 5.39 or above is in scope
(F) Once you have a "use VERSION" declaration that calls for a Perl version of at
least 5.39, you cannot have a subsequent one while the first is visible, even if it
requests a later version.
use VERSION of 5.39 or above is not permitted while another use VERSION is in scope
(F) Once you have a "use VERSION" declaration in scope, you cannot have a subsequent
one that calls for a Perl version of at least 5.39 while the first is visible.
Use \x{...} for more than two hex characters in regex; marked by <-- HERE in m/%s/
(F) In a regular expression, you said something like
(?[ [ \xBEEF ] ])
Perl isn't sure if you meant this
(?[ [ \x{BEEF} ] ])
or if you meant this
(?[ [ \x{BE} E F ] ])
You need to add either braces or blanks to disambiguate.
Using just the first character returned by \N{} in character class in regex; marked by
<-- HERE in m/%s/
(W regexp) Named Unicode character escapes "(\N{...})" may return a multi-character
sequence. Even though a character class is supposed to match just one character of
input, perl will match the whole thing correctly, except when the class is inverted
("[^...]"), or the escape is the beginning or final end point of a range. For these,
what should happen isn't clear at all. In these circumstances, Perl discards all but
the first character of the returned sequence, which is not likely what you want.
Using just the single character results returned by \p{} in (?[...]) in regex; marked by
<-- HERE in m/%s/
(W regexp) Extended character classes currently cannot handle operands that evaluate
to more than one character. These are removed from the results of the expansion of
the "\p{}".
This situation can happen, for example, in
(?[ \p{name=/KATAKANA/} ])
"KATAKANA LETTER AINU P" is a legal Unicode name (technically a "named sequence"), but
it is actually two characters. The above expression with match only the Unicode names
containing KATAKANA that represent single characters.
Using /u for '%s' instead of /%s in regex; marked by <-- HERE in m/%s/
(W regexp) You used a Unicode boundary ("\b{...}" or "\B{...}") in a portion of a
regular expression where the character set modifiers "/a" or "/aa" are in effect.
These two modifiers indicate an ASCII interpretation, and this doesn't make sense for
a Unicode definition. The generated regular expression will compile so that the
boundary uses all of Unicode. No other portion of the regular expression is affected.
Using !~ with %s doesn't make sense
(F) Using the "!~" operator with "s///r", "tr///r" or "y///r" is currently reserved
for future use, as the exact behavior has not been decided. (Simply returning the
boolean opposite of the modified string is usually not particularly useful.)
UTF-16 surrogate U+%X
(S surrogate) You had a UTF-16 surrogate in a context where they are not considered
acceptable. These code points, between U+D800 and U+DFFF (inclusive), are used by
Unicode only for UTF-16. However, Perl internally allows all unsigned integer code
points (up to the size limit available on your platform), including surrogates. But
these can cause problems when being input or output, which is likely where this
message came from. If you really really know what you are doing you can turn off this
warning by "no warnings 'surrogate';".
Value of %s can be "0"; test with defined()
(W misc) In a conditional expression, you used <HANDLE>, <*> (glob), each(), or
readdir() as a boolean value. Each of these constructs can return a value of "0";
that would make the conditional expression false, which is probably not what you
intended. When using these constructs in conditional expressions, test their values
with the "defined" operator.
Value of CLI symbol "%s" too long
(W misc) A warning peculiar to VMS. Perl tried to read the value of an %ENV element
from a CLI symbol table, and found a resultant string longer than 1024 characters.
The return value has been truncated to 1024 characters.
Variable "%s" is not available
(W closure) During compilation, an inner named subroutine or eval is attempting to
capture an outer lexical that is not currently available. This can happen for one of
two reasons. First, the outer lexical may be declared in an outer anonymous
subroutine that has not yet been created. (Remember that named subs are created at
compile time, while anonymous subs are created at run-time.) For example,
sub { my $x; sub f { $x } }
At the time that f is created, it can't capture the current value of $x, since the
anonymous subroutine hasn't been created yet. Conversely, the following won't give a
warning since the anonymous subroutine has by now been created and is live:
sub { my $x; eval 'sub f { $x }' }->();
The second situation is caused by an eval accessing a variable that has gone out of
scope, for example,
sub f {
my $x;
sub { eval '$x' }
}
f()->();
Here, when the '$x' in the eval is being compiled, f() is not currently being
executed, so its $x is not available for capture.
Variable "%s" is not imported%s
(S misc) With "use strict" in effect, you referred to a global variable that you
apparently thought was imported from another module, because something else of the
same name (usually a subroutine) is exported by that module. It usually means you put
the wrong funny character on the front of your variable. It is also possible you used
an "our" variable whose scope has ended.
Variable length lookbehind not implemented in regex m/%s/
(F) This message no longer should be raised as of Perl 5.30. It is retained in this
document as a convenience for people using an earlier Perl version.
In Perl 5.30 and earlier, lookbehind is allowed only for subexpressions whose length
is fixed and known at compile time. For positive lookbehind, you can use the "\K"
regex construct as a way to get the equivalent functionality. See (?<=pattern) and \K
in perlre.
Starting in Perl 5.18, there are non-obvious Unicode rules under "/i" that can match
variably, but which you might not think could. For example, the substring "ss" can
match the single character LATIN SMALL LETTER SHARP S. Here's a complete list of the
current ones affecting ASCII characters:
ASCII
sequence Matches single letter under /i
FF U+FB00 LATIN SMALL LIGATURE FF
FFI U+FB03 LATIN SMALL LIGATURE FFI
FFL U+FB04 LATIN SMALL LIGATURE FFL
FI U+FB01 LATIN SMALL LIGATURE FI
FL U+FB02 LATIN SMALL LIGATURE FL
SS U+00DF LATIN SMALL LETTER SHARP S
U+1E9E LATIN CAPITAL LETTER SHARP S
ST U+FB06 LATIN SMALL LIGATURE ST
U+FB05 LATIN SMALL LIGATURE LONG S T
This list is subject to change, but is quite unlikely to. Each ASCII sequence can be
any combination of upper- and lowercase.
You can avoid this by using a bracketed character class in the lookbehind assertion,
like
(?<![sS]t)
(?<![fF]f[iI])
This fools Perl into not matching the ligatures.
Another option for Perls starting with 5.16, if you only care about ASCII matches, is
to add the "/aa" modifier to the regex. This will exclude all these non-obvious
matches, thus getting rid of this message. You can also say
use if $] ge 5.016, re => '/aa';
to apply "/aa" to all regular expressions compiled within its scope. See re.
Variable length positive lookbehind with capturing is experimental in regex m/%s/
(W) Variable length positive lookbehind with capturing is not well defined. This
warning alerts you to the fact that you are using a construct which may change in a
future version of perl. See the documentation of Positive Lookbehind in perlre for
details. You may silence this warning with the following:
no warnings 'experimental::vlb';
Variable length negative lookbehind with capturing is experimental in regex m/%s/
(W) Variable length negative lookbehind with capturing is not well defined. This
warning alerts you to the fact that you are using a construct which may change in a
future version of perl. See the documentation of Negative Lookbehind in perlre for
details. You may silence this warning with the following:
no warnings 'experimental::vlb';
"%s" variable %s masks earlier declaration in same %s
(W shadow) A "my", "our", "state" or "field" variable has been redeclared in the
current scope or statement, effectively eliminating all access to the previous
instance. This is almost always a typographical error. Note that the earlier
variable will still exist until the end of the scope or until all closure references
to it are destroyed.
Variable syntax
(A) You've accidentally run your script through csh instead of Perl. Check the #!
line, or manually feed your script into Perl yourself.
Variable "%s" will not stay shared
(W closure) An inner (nested) named subroutine is referencing a lexical variable
defined in an outer named subroutine.
When the inner subroutine is called, it will see the value of the outer subroutine's
variable as it was before and during the *first* call to the outer subroutine; in this
case, after the first call to the outer subroutine is complete, the inner and outer
subroutines will no longer share a common value for the variable. In other words, the
variable will no longer be shared.
This problem can usually be solved by making the inner subroutine anonymous, using the
"sub {}" syntax. When inner anonymous subs that reference variables in outer
subroutines are created, they are automatically rebound to the current values of such
variables.
vector argument not supported with alpha versions
(S printf) The %vd (s)printf format does not support version objects with alpha parts.
Verb pattern '%s' has a mandatory argument in regex; marked by <-- HERE in m/%s/
(F) You used a verb pattern that requires an argument. Supply an argument or check
that you are using the right verb.
Verb pattern '%s' may not have an argument in regex; marked by <-- HERE in m/%s/
(F) You used a verb pattern that is not allowed an argument. Remove the argument or
check that you are using the right verb.
Version control conflict marker
(F) The parser found a line starting with "<<<<<<<", ">>>>>>>", or "=======". These
may be left by a version control system to mark conflicts after a failed merge
operation.
Version number must be a constant number
(P) The attempt to translate a "use Module n.n LIST" statement into its equivalent
"BEGIN" block found an internal inconsistency with the version number.
Version string '%s' contains invalid data; ignoring: '%s'
(W misc) The version string contains invalid characters at the end, which are being
ignored.
Warning: something's wrong
(W) You passed warn() an empty string (the equivalent of "warn """) or you called it
with no args and $@ was empty.
Warning: unable to close filehandle %s properly
(S) The implicit close() done by an open() got an error indication on the close().
This usually indicates your file system ran out of disk space.
Warning: unable to close filehandle properly: %s
Warning: unable to close filehandle %s properly: %s
(S io) There were errors during the implicit close() done on a filehandle when its
reference count reached zero while it was still open, e.g.:
{
open my $fh, '>', $file or die "open: '$file': $!\n";
print $fh $data or die "print: $!";
} # implicit close here
Because various errors may only be detected by close() (e.g. buffering could allow the
"print" in this example to return true even when the disk is full), it is dangerous to
ignore its result. So when it happens implicitly, perl will signal errors by warning.
Prior to version 5.22.0, perl ignored such errors, so the common idiom shown above was
liable to cause silent data loss.
Warning: Use of "%s" without parentheses is ambiguous
(S ambiguous) You wrote a unary operator followed by something that looks like a
binary operator that could also have been interpreted as a term or unary operator.
For instance, if you know that the rand function has a default argument of 1.0, and
you write
rand + 5;
you may THINK you wrote the same thing as
rand() + 5;
but in actual fact, you got
rand(+5);
So put in parentheses to say what you really mean.
when is deprecated
(D deprecated::smartmatch) "when" depends on smartmatch, which is deprecated.
Additionally, it has several special cases that may not be immediately obvious, and it
will be removed in Perl 5.42. See the explanation under "Experimental Details on
given and when" in perlsyn.
Wide character in %s
(S utf8) Perl met a wide character (ordinal >255) when it wasn't expecting one. This
warning is by default on for I/O (like print).
If this warning does come from I/O, the easiest way to quiet it is simply to add the
":utf8" layer, e.g., "binmode STDOUT, ':utf8'". Another way to turn off the warning
is to add "no warnings 'utf8';" but that is often closer to cheating. In general, you
are supposed to explicitly mark the filehandle with an encoding, see open and
"binmode" in perlfunc.
If the warning comes from other than I/O, this diagnostic probably indicates that
incorrect results are being obtained. You should examine your code to determine how a
wide character is getting to an operation that doesn't handle them.
Wide character (U+%X) in %s
(W locale) While in a single-byte locale (i.e., a non-UTF-8 one), a multi-byte
character was encountered. Perl considers this character to be the specified Unicode
code point. Combining non-UTF-8 locales and Unicode is dangerous. Almost certainly
some characters will have two different representations. For example, in the ISO
8859-7 (Greek) locale, the code point 0xC3 represents a Capital Gamma. But so also
does 0x393. This will make string comparisons unreliable.
You likely need to figure out how this multi-byte character got mixed up with your
single-byte locale (or perhaps you thought you had a UTF-8 locale, but Perl
disagrees).
Within []-length '%c' not allowed
(F) The count in the (un)pack template may be replaced by "[TEMPLATE]" only if
"TEMPLATE" always matches the same amount of packed bytes that can be determined from
the template alone. This is not possible if it contains any of the codes @, /, U, u,
w or a *-length. Redesign the template.
While trying to resolve method call %s->%s() can not locate package "%s" yet it is
mentioned in @%s::ISA (perhaps you forgot to load "%s"?)
(W syntax) It is possible that the @ISA contains a misspelled or never loaded package
name, which can result in perl choosing an unexpected parent class's method to resolve
the method call. If this is deliberate you can do something like
@Missing::Package::ISA = ();
to silence the warnings, otherwise you should correct the package name, or ensure that
the package is loaded prior to the method call.
%s() with negative argument
(S misc) Certain operations make no sense with negative arguments. Warning is given
and the operation is not done.
write() on closed filehandle %s
(W closed) The filehandle you're writing to got itself closed sometime before now.
Check your control flow.
%s "\x%X" does not map to Unicode
(S utf8) When reading in different encodings, Perl tries to map everything into
Unicode characters. The bytes you read in are not legal in this encoding. For
example
utf8 "\xE4" does not map to Unicode
if you try to read in the a-diaereses Latin-1 as UTF-8.
'X' outside of string
(F) You had a (un)pack template that specified a relative position before the
beginning of the string being (un)packed. See "pack" in perlfunc.
'x' outside of string in unpack
(F) You had an unpack template that specified a relative position after the end of the
string being unpacked. See "pack" in perlfunc.
YOU HAVEN'T DISABLED SET-ID SCRIPTS IN THE KERNEL YET!
(F) And you probably never will, because you probably don't have the sources to your
kernel, and your vendor probably doesn't give a rip about what you want. There is a
vulnerability anywhere that you have a set-id script, and to close it you need to
remove the set-id bit from the script that you're attempting to run. To actually run
the script set-id, your best bet is to put a set-id C wrapper around your script.
You need to quote "%s"
(W syntax) You assigned a bareword as a signal handler name:
$SIG{...} = foo;
However, this will not make "sub foo" the signal handler. Instead, Perl will call the
subroutine when the assignment is executed and use the returned value as the signal
handler, which is probably not what you want. (If it is what you want, put "()" after
the subroutine name to avoid the warning.)
To register the subroutine as the signal handler, take a reference to it:
$SIG{...} = \&foo;
Your random numbers are not that random
(F) When trying to initialize the random seed for hashes, Perl could not get any
randomness out of your system. This usually indicates Something Very Wrong.
Zero length \N{} in regex; marked by <-- HERE in m/%s/
(F) Named Unicode character escapes ("\N{...}") may return a zero-length sequence.
Such an escape was used in an extended character class, i.e. "(?[...])", or under
"use re 'strict'", which is not permitted. Check that the correct escape has been
used, and the correct charnames handler is in scope. The <-- HERE shows whereabouts
in the regular expression the problem was discovered.
SEE ALSO
warnings, diagnostics.