3 perldiag - various Perl diagnostics
7 These messages are classified as follows (listed in increasing order of
10 (W) A warning (optional).
11 (D) A deprecation (enabled by default).
12 (S) A severe warning (enabled by default).
13 (F) A fatal error (trappable).
14 (P) An internal error you should never see (trappable).
15 (X) A very fatal error (nontrappable).
16 (A) An alien error message (not generated by Perl).
18 The majority of messages from the first three classifications above
19 (W, D & S) can be controlled using the C<warnings> pragma.
21 If a message can be controlled by the C<warnings> pragma, its warning
22 category is included with the classification letter in the description
23 below. E.g. C<(W closed)> means a warning in the C<closed> category.
25 Optional warnings are enabled by using the C<warnings> pragma or the B<-w>
26 and B<-W> switches. Warnings may be captured by setting C<$SIG{__WARN__}>
27 to a reference to a routine that will be called on each warning instead
28 of printing it. See L<perlvar>.
30 Severe warnings are always enabled, unless they are explicitly disabled
31 with the C<warnings> pragma or the B<-X> switch.
33 Trappable errors may be trapped using the eval operator. See
34 L<perlfunc/eval>. In almost all cases, warnings may be selectively
35 disabled or promoted to fatal errors using the C<warnings> pragma.
38 The messages are in alphabetical order, without regard to upper or
39 lower-case. Some of these messages are generic. Spots that vary are
40 denoted with a %s or other printf-style escape. These escapes are
41 ignored by the alphabetical order, as are all characters other than
42 letters. To look up your message, just ignore anything that is not a
47 =item accept() on closed socket %s
49 (W closed) You tried to do an accept on a closed socket. Did you forget
50 to check the return value of your socket() call? See
53 =item Aliasing via reference is experimental
55 (S experimental::refaliasing) This warning is emitted if you use
56 a reference constructor on the left-hand side of an assignment to
57 alias one variable to another. Simply suppress the warning if you
58 want to use the feature, but know that in doing so you are taking
59 the risk of using an experimental feature which may change or be
60 removed in a future Perl version:
62 no warnings "experimental::refaliasing";
63 use feature "refaliasing";
66 =item Allocation too large: %x
68 (X) You can't allocate more than 64K on an MS-DOS machine.
70 =item '%c' allowed only after types %s in %s
72 (F) The modifiers '!', '<' and '>' are allowed in pack() or unpack() only
73 after certain types. See L<perlfunc/pack>.
75 =item Ambiguous call resolved as CORE::%s(), qualify as such or use &
77 (W ambiguous) A subroutine you have declared has the same name as a Perl
78 keyword, and you have used the name without qualification for calling
79 one or the other. Perl decided to call the builtin because the
80 subroutine is not imported.
82 To force interpretation as a subroutine call, either put an ampersand
83 before the subroutine name, or qualify the name with its package.
84 Alternatively, you can import the subroutine (or pretend that it's
85 imported with the C<use subs> pragma).
87 To silently interpret it as the Perl operator, use the C<CORE::> prefix
88 on the operator (e.g. C<CORE::log($x)>) or declare the subroutine
89 to be an object method (see L<perlsub/"Subroutine Attributes"> or
92 =item Ambiguous range in transliteration operator
94 (F) You wrote something like C<tr/a-z-0//> which doesn't mean anything at
95 all. To include a C<-> character in a transliteration, put it either
96 first or last. (In the past, C<tr/a-z-0//> was synonymous with
97 C<tr/a-y//>, which was probably not what you would have expected.)
99 =item Ambiguous use of %s resolved as %s
101 (S ambiguous) You said something that may not be interpreted the way
102 you thought. Normally it's pretty easy to disambiguate it by supplying
103 a missing quote, operator, parenthesis pair or declaration.
105 =item Ambiguous use of -%s resolved as -&%s()
107 (S ambiguous) You wrote something like C<-foo>, which might be the
108 string C<"-foo">, or a call to the function C<foo>, negated. If you meant
109 the string, just write C<"-foo">. If you meant the function call,
112 =item Ambiguous use of %c resolved as operator %c
114 (S ambiguous) C<%>, C<&>, and C<*> are both infix operators (modulus,
115 bitwise and, and multiplication) I<and> initial special characters
116 (denoting hashes, subroutines and typeglobs), and you said something
117 like C<*foo * foo> that might be interpreted as either of them. We
118 assumed you meant the infix operator, but please try to make it more
119 clear -- in the example given, you might write C<*foo * foo()> if you
120 really meant to multiply a glob by the result of calling a function.
122 =item Ambiguous use of %c{%s} resolved to %c%s
124 (W ambiguous) You wrote something like C<@{foo}>, which might be
125 asking for the variable C<@foo>, or it might be calling a function
126 named foo, and dereferencing it as an array reference. If you wanted
127 the variable, you can just write C<@foo>. If you wanted to call the
128 function, write C<@{foo()}> ... or you could just not have a variable
129 and a function with the same name, and save yourself a lot of trouble.
131 =item Ambiguous use of %c{%s[...]} resolved to %c%s[...]
133 =item Ambiguous use of %c{%s{...}} resolved to %c%s{...}
135 (W ambiguous) You wrote something like C<${foo[2]}> (where foo represents
136 the name of a Perl keyword), which might be looking for element number
137 2 of the array named C<@foo>, in which case please write C<$foo[2]>, or you
138 might have meant to pass an anonymous arrayref to the function named
139 foo, and then do a scalar deref on the value it returns. If you meant
140 that, write C<${foo([2])}>.
142 In regular expressions, the C<${foo[2]}> syntax is sometimes necessary
143 to disambiguate between array subscripts and character classes.
144 C</$length[2345]/>, for instance, will be interpreted as C<$length> followed
145 by the character class C<[2345]>. If an array subscript is what you
146 want, you can avoid the warning by changing C</${length[2345]}/> to the
147 unsightly C</${\$length[2345]}/>, by renaming your array to something
148 that does not coincide with a built-in keyword, or by simply turning
149 off warnings with C<no warnings 'ambiguous';>.
151 =item '|' and '<' may not both be specified on command line
153 (F) An error peculiar to VMS. Perl does its own command line
154 redirection, and found that STDIN was a pipe, and that you also tried to
155 redirect STDIN using '<'. Only one STDIN stream to a customer, please.
157 =item '|' and '>' may not both be specified on command line
159 (F) An error peculiar to VMS. Perl does its own command line
160 redirection, and thinks you tried to redirect stdout both to a file and
161 into a pipe to another command. You need to choose one or the other,
162 though nothing's stopping you from piping into a program or Perl script
163 which 'splits' output into two streams, such as
165 open(OUT,">$ARGV[0]") or die "Can't write to $ARGV[0]: $!";
172 =item Applying %s to %s will act on scalar(%s)
174 (W misc) The pattern match (C<//>), substitution (C<s///>), and
175 transliteration (C<tr///>) operators work on scalar values. If you apply
176 one of them to an array or a hash, it will convert the array or hash to
177 a scalar value (the length of an array, or the population info of a
178 hash) and then work on that scalar value. This is probably not what
179 you meant to do. See L<perlfunc/grep> and L<perlfunc/map> for
182 =item Arg too short for msgsnd
184 (F) msgsnd() requires a string at least as long as sizeof(long).
186 =item Argument "%s" isn't numeric%s
188 (W numeric) The indicated string was fed as an argument to an operator
189 that expected a numeric value instead. If you're fortunate the message
190 will identify which operator was so unfortunate.
192 =item Argument list not closed for PerlIO layer "%s"
194 (W layer) When pushing a layer with arguments onto the Perl I/O
195 system you forgot the ) that closes the argument list. (Layers
196 take care of transforming data between external and internal
197 representations.) Perl stopped parsing the layer list at this
198 point and did not attempt to push this layer. If your program
199 didn't explicitly request the failing operation, it may be the
200 result of the value of the environment variable PERLIO.
202 =item Argument "%s" treated as 0 in increment (++)
204 (W numeric) The indicated string was fed as an argument to the C<++>
205 operator which expects either a number or a string matching
206 C</^[a-zA-Z]*[0-9]*\z/>. See L<perlop/Auto-increment and
207 Auto-decrement> for details.
209 =item assertion botched: %s
211 (X) The malloc package that comes with Perl had an internal failure.
213 =item Assertion %s failed: file "%s", line %d
215 (X) A general assertion failed. The file in question must be examined.
217 =item Assigned value is not a reference
219 (F) You tried to assign something that was not a reference to an lvalue
220 reference (e.g., C<\$x = $y>). If you meant to make $x an alias to $y, use
223 =item Assigned value is not %s reference
225 (F) You tried to assign a reference to a reference constructor, but the
226 two references were not of the same type. You cannot alias a scalar to
227 an array, or an array to a hash; the two types must match.
232 \$x = $y; # error; did you mean \$y?
234 =item Assigning non-zero to $[ is no longer possible
236 (F) When the "array_base" feature is disabled (e.g., under C<use v5.16;>)
237 the special variable C<$[>, which is deprecated, is now a fixed zero value.
239 =item Assignment to both a list and a scalar
241 (F) If you assign to a conditional operator, the 2nd and 3rd arguments
242 must either both be scalars or both be lists. Otherwise Perl won't
243 know which context to supply to the right side.
245 =item <> at require-statement should be quotes
247 (F) You wrote C<< require <file> >> when you should have written
250 =item Attempt to access disallowed key '%s' in a restricted hash
252 (F) The failing code has attempted to get or set a key which is not in
253 the current set of allowed keys of a restricted hash.
255 =item Attempt to bless into a freed package
257 (F) You wrote C<bless $foo> with one argument after somehow causing
258 the current package to be freed. Perl cannot figure out what to
259 do, so it throws up in hands in despair.
261 =item Attempt to bless into a reference
263 (F) The CLASSNAME argument to the bless() operator is expected to be
264 the name of the package to bless the resulting object into. You've
265 supplied instead a reference to something: perhaps you wrote
271 bless $self, ref($proto) || $proto;
273 If you actually want to bless into the stringified version
274 of the reference supplied, you need to stringify it yourself, for
277 bless $self, "$proto";
279 =item Attempt to clear deleted array
281 (S debugging) An array was assigned to when it was being freed.
282 Freed values are not supposed to be visible to Perl code. This
283 can also happen if XS code calls C<av_clear> from a custom magic
284 callback on the array.
286 =item Attempt to delete disallowed key '%s' from a restricted hash
288 (F) The failing code attempted to delete from a restricted hash a key
289 which is not in its key set.
291 =item Attempt to delete readonly key '%s' from a restricted hash
293 (F) The failing code attempted to delete a key whose value has been
294 declared readonly from a restricted hash.
296 =item Attempt to free non-arena SV: 0x%x
298 (S internal) All SV objects are supposed to be allocated from arenas
299 that will be garbage collected on exit. An SV was discovered to be
300 outside any of those arenas.
302 =item Attempt to free nonexistent shared string '%s'%s
304 (S internal) Perl maintains a reference-counted internal table of
305 strings to optimize the storage and access of hash keys and other
306 strings. This indicates someone tried to decrement the reference count
307 of a string that can no longer be found in the table.
309 =item Attempt to free temp prematurely: SV 0x%x
311 (S debugging) Mortalized values are supposed to be freed by the
312 free_tmps() routine. This indicates that something else is freeing the
313 SV before the free_tmps() routine gets a chance, which means that the
314 free_tmps() routine will be freeing an unreferenced scalar when it does
317 =item Attempt to free unreferenced glob pointers
319 (S internal) The reference counts got screwed up on symbol aliases.
321 =item Attempt to free unreferenced scalar: SV 0x%x
323 (S internal) Perl went to decrement the reference count of a scalar to
324 see if it would go to 0, and discovered that it had already gone to 0
325 earlier, and should have been freed, and in fact, probably was freed.
326 This could indicate that SvREFCNT_dec() was called too many times, or
327 that SvREFCNT_inc() was called too few times, or that the SV was
328 mortalized when it shouldn't have been, or that memory has been
331 =item Attempt to pack pointer to temporary value
333 (W pack) You tried to pass a temporary value (like the result of a
334 function, or a computed expression) to the "p" pack() template. This
335 means the result contains a pointer to a location that could become
336 invalid anytime, even before the end of the current statement. Use
337 literals or global values as arguments to the "p" pack() template to
340 =item Attempt to reload %s aborted.
342 (F) You tried to load a file with C<use> or C<require> that failed to
343 compile once already. Perl will not try to compile this file again
344 unless you delete its entry from %INC. See L<perlfunc/require> and
347 =item Attempt to set length of freed array
349 (W misc) You tried to set the length of an array which has
350 been freed. You can do this by storing a reference to the
351 scalar representing the last index of an array and later
352 assigning through that reference. For example
354 $r = do {my @a; \$#a};
357 =item Attempt to use reference as lvalue in substr
359 (W substr) You supplied a reference as the first argument to substr()
360 used as an lvalue, which is pretty strange. Perhaps you forgot to
361 dereference it first. See L<perlfunc/substr>.
363 =item Attribute "locked" is deprecated
365 (D deprecated) You have used the attributes pragma to modify the
366 "locked" attribute on a code reference. The :locked attribute is
367 obsolete, has had no effect since 5005 threads were removed, and
368 will be removed in a future release of Perl 5.
370 =item Attribute prototype(%s) discards earlier prototype attribute in same sub
372 (W misc) A sub was declared as sub foo : prototype(A) : prototype(B) {}, for
373 example. Since each sub can only have one prototype, the earlier
374 declaration(s) are discarded while the last one is applied.
376 =item Attribute "unique" is deprecated
378 (D deprecated) You have used the attributes pragma to modify
379 the "unique" attribute on an array, hash or scalar reference.
380 The :unique attribute has had no effect since Perl 5.8.8, and
381 will be removed in a future release of Perl 5.
383 =item av_reify called on tied array
385 (S debugging) This indicates that something went wrong and Perl got I<very>
386 confused about C<@_> or C<@DB::args> being tied.
388 =item Bad arg length for %s, is %u, should be %d
390 (F) You passed a buffer of the wrong size to one of msgctl(), semctl()
391 or shmctl(). In C parlance, the correct sizes are, respectively,
392 S<sizeof(struct msqid_ds *)>, S<sizeof(struct semid_ds *)>, and
393 S<sizeof(struct shmid_ds *)>.
395 =item Bad evalled substitution pattern
397 (F) You've used the C</e> switch to evaluate the replacement for a
398 substitution, but perl found a syntax error in the code to evaluate,
399 most likely an unexpected right brace '}'.
401 =item Bad filehandle: %s
403 (F) A symbol was passed to something wanting a filehandle, but the
404 symbol has no filehandle associated with it. Perhaps you didn't do an
405 open(), or did it in another package.
407 =item Bad free() ignored
409 (S malloc) An internal routine called free() on something that had never
410 been malloc()ed in the first place. Mandatory, but can be disabled by
411 setting environment variable C<PERL_BADFREE> to 0.
413 This message can be seen quite often with DB_File on systems with "hard"
414 dynamic linking, like C<AIX> and C<OS/2>. It is a bug of C<Berkeley DB>
415 which is left unnoticed if C<DB> uses I<forgiving> system malloc().
419 (P) One of the internal hash routines was passed a null HV pointer.
421 =item Badly placed ()'s
423 (A) You've accidentally run your script through B<csh> instead
424 of Perl. Check the #! line, or manually feed your script into
427 =item Bad name after %s
429 (F) You started to name a symbol by using a package prefix, and then
430 didn't finish the symbol. In particular, you can't interpolate outside
439 $sym = "mypack::$var";
441 =item Bad plugin affecting keyword '%s'
443 (F) An extension using the keyword plugin mechanism violated the
446 =item Bad realloc() ignored
448 (S malloc) An internal routine called realloc() on something that
449 had never been malloc()ed in the first place. Mandatory, but can
450 be disabled by setting the environment variable C<PERL_BADFREE> to 1.
452 =item Bad symbol for array
454 (P) An internal request asked to add an array entry to something that
455 wasn't a symbol table entry.
457 =item Bad symbol for dirhandle
459 (P) An internal request asked to add a dirhandle entry to something
460 that wasn't a symbol table entry.
462 =item Bad symbol for filehandle
464 (P) An internal request asked to add a filehandle entry to something
465 that wasn't a symbol table entry.
467 =item Bad symbol for hash
469 (P) An internal request asked to add a hash entry to something that
470 wasn't a symbol table entry.
472 =item Bareword found in conditional
474 (W bareword) The compiler found a bareword where it expected a
475 conditional, which often indicates that an || or && was parsed as part
476 of the last argument of the previous construct, for example:
480 It may also indicate a misspelled constant that has been interpreted as
483 use constant TYPO => 1;
484 if (TYOP) { print "foo" }
486 The C<strict> pragma is useful in avoiding such errors.
488 =item Bareword "%s" not allowed while "strict subs" in use
490 (F) With "strict subs" in use, a bareword is only allowed as a
491 subroutine identifier, in curly brackets or to the left of the "=>"
492 symbol. Perhaps you need to predeclare a subroutine?
494 =item Bareword "%s" refers to nonexistent package
496 (W bareword) You used a qualified bareword of the form C<Foo::>, but the
497 compiler saw no other uses of that namespace before that point. Perhaps
498 you need to predeclare a package?
500 =item BEGIN failed--compilation aborted
502 (F) An untrapped exception was raised while executing a BEGIN
503 subroutine. Compilation stops immediately and the interpreter is
506 =item BEGIN not safe after errors--compilation aborted
508 (F) Perl found a C<BEGIN {}> subroutine (or a C<use> directive, which
509 implies a C<BEGIN {}>) after one or more compilation errors had already
510 occurred. Since the intended environment for the C<BEGIN {}> could not
511 be guaranteed (due to the errors), and since subsequent code likely
512 depends on its correct operation, Perl just gave up.
514 =item \%d better written as $%d
516 (W syntax) Outside of patterns, backreferences live on as variables.
517 The use of backslashes is grandfathered on the right-hand side of a
518 substitution, but stylistically it's better to use the variable form
519 because other Perl programmers will expect it, and it works better if
520 there are more than 9 backreferences.
522 =item Binary number > 0b11111111111111111111111111111111 non-portable
524 (W portable) The binary number you specified is larger than 2**32-1
525 (4294967295) and therefore non-portable between systems. See
526 L<perlport> for more on portability concerns.
528 =item bind() on closed socket %s
530 (W closed) You tried to do a bind on a closed socket. Did you forget to
531 check the return value of your socket() call? See L<perlfunc/bind>.
533 =item binmode() on closed filehandle %s
535 (W unopened) You tried binmode() on a filehandle that was never opened.
536 Check your control flow and number of arguments.
538 =item Bit vector size > 32 non-portable
540 (W portable) Using bit vector sizes larger than 32 is non-portable.
542 =item Bizarre copy of %s
544 (P) Perl detected an attempt to copy an internal value that is not
547 =item Bizarre SvTYPE [%d]
549 (P) When starting a new thread or returning values from a thread, Perl
550 encountered an invalid data type.
552 =item Buffer overflow in prime_env_iter: %s
554 (W internal) A warning peculiar to VMS. While Perl was preparing to
555 iterate over %ENV, it encountered a logical name or symbol definition
556 which was too long, so it was truncated to the string shown.
558 =item Callback called exit
560 (F) A subroutine invoked from an external package via call_sv()
561 exited by calling exit.
563 =item %s() called too early to check prototype
565 (W prototype) You've called a function that has a prototype before the
566 parser saw a definition or declaration for it, and Perl could not check
567 that the call conforms to the prototype. You need to either add an
568 early prototype declaration for the subroutine in question, or move the
569 subroutine definition ahead of the call to get proper prototype
570 checking. Alternatively, if you are certain that you're calling the
571 function correctly, you may put an ampersand before the name to avoid
572 the warning. See L<perlsub>.
574 =item Calling POSIX::%s() is deprecated
576 (D deprecated) You called a function whose use is deprecated. See
577 the function's name in L<POSIX> for details.
581 (F) You passed an invalid number (like an infinity or not-a-number) to C<chr>.
583 =item Cannot compress %f in pack
585 (F) You tried compressing an infinity or not-a-number as an unsigned
586 integer with BER, which makes no sense.
588 =item Cannot compress integer in pack
590 (F) An argument to pack("w",...) was too large to compress.
591 The BER compressed integer format can only be used with positive
592 integers, and you attempted to compress a very large number (> 1e308).
593 See L<perlfunc/pack>.
595 =item Cannot compress negative numbers in pack
597 (F) An argument to pack("w",...) was negative. The BER compressed integer
598 format can only be used with positive integers. See L<perlfunc/pack>.
600 =item Cannot convert a reference to %s to typeglob
602 (F) You manipulated Perl's symbol table directly, stored a reference
603 in it, then tried to access that symbol via conventional Perl syntax.
604 The access triggers Perl to autovivify that typeglob, but it there is
605 no legal conversion from that type of reference to a typeglob.
607 =item Cannot copy to %s
609 (P) Perl detected an attempt to copy a value to an internal type that cannot
610 be directly assigned to.
612 =item Cannot find encoding "%s"
614 (S io) You tried to apply an encoding that did not exist to a filehandle,
615 either with open() or binmode().
617 =item Cannot pack %f with '%c'
619 (F) You tried converting an infinity or not-a-number to an integer,
620 which makes no sense.
622 =item Cannot printf %f with '%c'
624 (F) You tried printing an infinity or not-a-number as a character (%c),
625 which makes no sense. Maybe you meant '%s', or just stringifying it?
627 =item Cannot set tied @DB::args
629 (F) C<caller> tried to set C<@DB::args>, but found it tied. Tying C<@DB::args>
630 is not supported. (Before this error was added, it used to crash.)
632 =item Cannot tie unreifiable array
634 (P) You somehow managed to call C<tie> on an array that does not
635 keep a reference count on its arguments and cannot be made to
636 do so. Such arrays are not even supposed to be accessible to
637 Perl code, but are only used internally.
639 =item Can only compress unsigned integers in pack
641 (F) An argument to pack("w",...) was not an integer. The BER compressed
642 integer format can only be used with positive integers, and you attempted
643 to compress something else. See L<perlfunc/pack>.
645 =item Can't bless non-reference value
647 (F) Only hard references may be blessed. This is how Perl "enforces"
648 encapsulation of objects. See L<perlobj>.
650 =item Can't "break" in a loop topicalizer
652 (F) You called C<break>, but you're in a C<foreach> block rather than
653 a C<given> block. You probably meant to use C<next> or C<last>.
655 =item Can't "break" outside a given block
657 (F) You called C<break>, but you're not inside a C<given> block.
659 =item Can't call method "%s" on an undefined value
661 (F) You used the syntax of a method call, but the slot filled by the
662 object reference or package name contains an undefined value. Something
663 like this will reproduce the error:
666 process $BADREF 1,2,3;
667 $BADREF->process(1,2,3);
669 =item Can't call method "%s" on unblessed reference
671 (F) A method call must know in what package it's supposed to run. It
672 ordinarily finds this out from the object reference you supply, but you
673 didn't supply an object reference in this case. A reference isn't an
674 object reference until it has been blessed. See L<perlobj>.
676 =item Can't call method "%s" without a package or object reference
678 (F) You used the syntax of a method call, but the slot filled by the
679 object reference or package name contains an expression that returns a
680 defined value which is neither an object reference nor a package name.
681 Something like this will reproduce the error:
684 process $BADREF 1,2,3;
685 $BADREF->process(1,2,3);
687 =item Can't call mro_isa_changed_in() on anonymous symbol table
689 (P) Perl got confused as to whether a hash was a plain hash or a
690 symbol table hash when trying to update @ISA caches.
692 =item Can't call mro_method_changed_in() on anonymous symbol table
694 (F) An XS module tried to call C<mro_method_changed_in> on a hash that was
695 not attached to the symbol table.
697 =item Can't chdir to %s
699 (F) You called C<perl -x/foo/bar>, but F</foo/bar> is not a directory
700 that you can chdir to, possibly because it doesn't exist.
702 =item Can't check filesystem of script "%s" for nosuid
704 (P) For some reason you can't check the filesystem of the script for
707 =item Can't coerce %s to %s in %s
709 (F) Certain types of SVs, in particular real symbol table entries
710 (typeglobs), can't be forced to stop being what they are. So you can't
720 but then $foo no longer contains a glob.
722 =item Can't "continue" outside a when block
724 (F) You called C<continue>, but you're not inside a C<when>
727 =item Can't create pipe mailbox
729 (P) An error peculiar to VMS. The process is suffering from exhausted
730 quotas or other plumbing problems.
732 =item Can't declare %s in "%s"
734 (F) Only scalar, array, and hash variables may be declared as "my", "our" or
735 "state" variables. They must have ordinary identifiers as names.
737 =item Can't "default" outside a topicalizer
739 (F) You have used a C<default> block that is neither inside a
740 C<foreach> loop nor a C<given> block. (Note that this error is
741 issued on exit from the C<default> block, so you won't get the
742 error if you use an explicit C<continue>.)
744 =item Can't do inplace edit: %s is not a regular file
746 (S inplace) You tried to use the B<-i> switch on a special file, such as
747 a file in /dev, a FIFO or an uneditable directory. The file was ignored.
749 =item Can't do inplace edit on %s: %s
751 (S inplace) The creation of the new file failed for the indicated
754 =item Can't do inplace edit without backup
756 (F) You're on a system such as MS-DOS that gets confused if you try
757 reading from a deleted (but still opened) file. You have to say
758 C<-i.bak>, or some such.
760 =item Can't do inplace edit: %s would not be unique
762 (S inplace) Your filesystem does not support filenames longer than 14
763 characters and Perl was unable to create a unique filename during
764 inplace editing with the B<-i> switch. The file was ignored.
766 =item Can't do waitpid with flags
768 (F) This machine doesn't have either waitpid() or wait4(), so only
769 waitpid() without flags is emulated.
771 =item Can't emulate -%s on #! line
773 (F) The #! line specifies a switch that doesn't make sense at this
774 point. For example, it'd be kind of silly to put a B<-x> on the #!
777 =item Can't %s %s-endian %ss on this platform
779 (F) Your platform's byte-order is neither big-endian nor little-endian,
780 or it has a very strange pointer size. Packing and unpacking big- or
781 little-endian floating point values and pointers may not be possible.
782 See L<perlfunc/pack>.
784 =item Can't exec "%s": %s
786 (W exec) A system(), exec(), or piped open call could not execute the
787 named program for the indicated reason. Typical reasons include: the
788 permissions were wrong on the file, the file wasn't found in
789 C<$ENV{PATH}>, the executable in question was compiled for another
790 architecture, or the #! line in a script points to an interpreter that
791 can't be run for similar reasons. (Or maybe your system doesn't support
796 (F) Perl was trying to execute the indicated program for you because
797 that's what the #! line said. If that's not what you wanted, you may
798 need to mention "perl" on the #! line somewhere.
800 =item Can't execute %s
802 (F) You used the B<-S> switch, but the copies of the script to execute
803 found in the PATH did not have correct permissions.
805 =item Can't find an opnumber for "%s"
807 (F) A string of a form C<CORE::word> was given to prototype(), but there
808 is no builtin with the name C<word>.
810 =item Can't find %s character property "%s"
812 (F) You used C<\p{}> or C<\P{}> but the character property by that name
813 could not be found. Maybe you misspelled the name of the property?
814 See L<perluniprops/Properties accessible through \p{} and \P{}>
815 for a complete list of available official properties.
817 =item Can't find label %s
819 (F) You said to goto a label that isn't mentioned anywhere that it's
820 possible for us to go to. See L<perlfunc/goto>.
822 =item Can't find %s on PATH
824 (F) You used the B<-S> switch, but the script to execute could not be
827 =item Can't find %s on PATH, '.' not in PATH
829 (F) You used the B<-S> switch, but the script to execute could not be
830 found in the PATH, or at least not with the correct permissions. The
831 script exists in the current directory, but PATH prohibits running it.
833 =item Can't find string terminator %s anywhere before EOF
835 (F) Perl strings can stretch over multiple lines. This message means
836 that the closing delimiter was omitted. Because bracketed quotes count
837 nesting levels, the following is missing its final parenthesis:
839 print q(The character '(' starts a side comment.);
841 If you're getting this error from a here-document, you may have
842 included unseen whitespace before or after your closing tag or there
843 may not be a linebreak after it. A good programmer's editor will have
844 a way to help you find these characters (or lack of characters). See
845 L<perlop> for the full details on here-documents.
847 =item Can't find Unicode property definition "%s"
849 (F) You may have tried to use C<\p> which means a Unicode
850 property (for example C<\p{Lu}> matches all uppercase
851 letters). If you did mean to use a Unicode property, see
852 L<perluniprops/Properties accessible through \p{} and \P{}>
853 for a complete list of available properties. If you didn't
854 mean to use a Unicode property, escape the C<\p>, either by
855 C<\\p> (just the C<\p>) or by C<\Q\p> (the rest of the string, or
860 (F) A fatal error occurred while trying to fork while opening a
863 =item Can't fork, trying again in 5 seconds
865 (W pipe) A fork in a piped open failed with EAGAIN and will be retried
868 =item Can't get filespec - stale stat buffer?
870 (S) A warning peculiar to VMS. This arises because of the difference
871 between access checks under VMS and under the Unix model Perl assumes.
872 Under VMS, access checks are done by filename, rather than by bits in
873 the stat buffer, so that ACLs and other protections can be taken into
874 account. Unfortunately, Perl assumes that the stat buffer contains all
875 the necessary information, and passes it, instead of the filespec, to
876 the access-checking routine. It will try to retrieve the filespec using
877 the device name and FID present in the stat buffer, but this works only
878 if you haven't made a subsequent call to the CRTL stat() routine,
879 because the device name is overwritten with each call. If this warning
880 appears, the name lookup failed, and the access-checking routine gave up
881 and returned FALSE, just to be conservative. (Note: The access-checking
882 routine knows about the Perl C<stat> operator and file tests, so you
883 shouldn't ever see this warning in response to a Perl command; it arises
884 only if some internal code takes stat buffers lightly.)
886 =item Can't get pipe mailbox device name
888 (P) An error peculiar to VMS. After creating a mailbox to act as a
889 pipe, Perl can't retrieve its name for later use.
891 =item Can't get SYSGEN parameter value for MAXBUF
893 (P) An error peculiar to VMS. Perl asked $GETSYI how big you want your
894 mailbox buffers to be, and didn't get an answer.
896 =item Can't "goto" into the middle of a foreach loop
898 (F) A "goto" statement was executed to jump into the middle of a foreach
899 loop. You can't get there from here. See L<perlfunc/goto>.
901 =item Can't "goto" out of a pseudo block
903 (F) A "goto" statement was executed to jump out of what might look like
904 a block, except that it isn't a proper block. This usually occurs if
905 you tried to jump out of a sort() block or subroutine, which is a no-no.
906 See L<perlfunc/goto>.
908 =item Can't goto subroutine from an eval-%s
910 (F) The "goto subroutine" call can't be used to jump out of an eval
913 =item Can't goto subroutine from a sort sub (or similar callback)
915 (F) The "goto subroutine" call can't be used to jump out of the
916 comparison sub for a sort(), or from a similar callback (such
917 as the reduce() function in List::Util).
919 =item Can't goto subroutine outside a subroutine
921 (F) The deeply magical "goto subroutine" call can only replace one
922 subroutine call for another. It can't manufacture one out of whole
923 cloth. In general you should be calling it out of only an AUTOLOAD
924 routine anyway. See L<perlfunc/goto>.
926 =item Can't ignore signal CHLD, forcing to default
928 (W signal) Perl has detected that it is being run with the SIGCHLD
929 signal (sometimes known as SIGCLD) disabled. Since disabling this
930 signal will interfere with proper determination of exit status of child
931 processes, Perl has reset the signal to its default value. This
932 situation typically indicates that the parent program under which Perl
933 may be running (e.g. cron) is being very careless.
935 =item Can't kill a non-numeric process ID
937 (F) Process identifiers must be (signed) integers. It is a fatal error to
938 attempt to kill() an undefined, empty-string or otherwise non-numeric
941 =item Can't "last" outside a loop block
943 (F) A "last" statement was executed to break out of the current block,
944 except that there's this itty bitty problem called there isn't a current
945 block. Note that an "if" or "else" block doesn't count as a "loopish"
946 block, as doesn't a block given to sort(), map() or grep(). You can
947 usually double the curlies to get the same effect though, because the
948 inner curlies will be considered a block that loops once. See
951 =item Can't linearize anonymous symbol table
953 (F) Perl tried to calculate the method resolution order (MRO) of a
954 package, but failed because the package stash has no name.
956 =item Can't load '%s' for module %s
958 (F) The module you tried to load failed to load a dynamic extension.
959 This may either mean that you upgraded your version of perl to one
960 that is incompatible with your old dynamic extensions (which is known
961 to happen between major versions of perl), or (more likely) that your
962 dynamic extension was built against an older version of the library
963 that is installed on your system. You may need to rebuild your old
966 =item Can't localize lexical variable %s
968 (F) You used local on a variable name that was previously declared as a
969 lexical variable using "my" or "state". This is not allowed. If you
970 want to localize a package variable of the same name, qualify it with
973 =item Can't localize through a reference
975 (F) You said something like C<local $$ref>, which Perl can't currently
976 handle, because when it goes to restore the old value of whatever $ref
977 pointed to after the scope of the local() is finished, it can't be sure
978 that $ref will still be a reference.
980 =item Can't locate %s
982 (F) You said to C<do> (or C<require>, or C<use>) a file that couldn't be found.
983 Perl looks for the file in all the locations mentioned in @INC, unless
984 the file name included the full path to the file. Perhaps you need
985 to set the PERL5LIB or PERL5OPT environment variable to say where the
986 extra library is, or maybe the script needs to add the library name
987 to @INC. Or maybe you just misspelled the name of the file. See
988 L<perlfunc/require> and L<lib>.
990 =item Can't locate auto/%s.al in @INC
992 (F) A function (or method) was called in a package which allows
993 autoload, but there is no function to autoload. Most probable causes
994 are a misprint in a function/method name or a failure to C<AutoSplit>
995 the file, say, by doing C<make install>.
997 =item Can't locate loadable object for module %s in @INC
999 (F) The module you loaded is trying to load an external library, like
1000 for example, F<foo.so> or F<bar.dll>, but the L<DynaLoader> module was
1001 unable to locate this library. See L<DynaLoader>.
1003 =item Can't locate object method "%s" via package "%s"
1005 (F) You called a method correctly, and it correctly indicated a package
1006 functioning as a class, but that package doesn't define that particular
1007 method, nor does any of its base classes. See L<perlobj>.
1009 =item Can't locate object method "%s" via package "%s" (perhaps you forgot
1012 (F) You called a method on a class that did not exist, and the method
1013 could not be found in UNIVERSAL. This often means that a method
1014 requires a package that has not been loaded.
1016 =item Can't locate package %s for @%s::ISA
1018 (W syntax) The @ISA array contained the name of another package that
1019 doesn't seem to exist.
1021 =item Can't locate PerlIO%s
1023 (F) You tried to use in open() a PerlIO layer that does not exist,
1024 e.g. open(FH, ">:nosuchlayer", "somefile").
1026 =item Can't make list assignment to %ENV on this system
1028 (F) List assignment to %ENV is not supported on some systems, notably
1031 =item Can't make loaded symbols global on this platform while loading %s
1033 (S) A module passed the flag 0x01 to DynaLoader::dl_load_file() to request
1034 that symbols from the stated file are made available globally within the
1035 process, but that functionality is not available on this platform. Whilst
1036 the module likely will still work, this may prevent the perl interpreter
1037 from loading other XS-based extensions which need to link directly to
1038 functions defined in the C or XS code in the stated file.
1040 =item Can't modify %s in %s
1042 (F) You aren't allowed to assign to the item indicated, or otherwise try
1043 to change it, such as with an auto-increment.
1045 =item Can't modify nonexistent substring
1047 (P) The internal routine that does assignment to a substr() was handed
1050 =item Can't modify non-lvalue subroutine call
1052 (F) Subroutines meant to be used in lvalue context should be declared as
1053 such. See L<perlsub/"Lvalue subroutines">.
1055 =item Can't modify reference to %s in %s assignment
1057 (F) Only a limited number of constructs can be used as the argument to a
1058 reference constructor on the left-hand side of an assignment, and what
1059 you used was not one of them. See L<perlref/Assigning to References>.
1061 =item Can't modify reference to localized parenthesized array in list
1064 (F) Assigning to C<\local(@array)> or C<\(local @array)> is not supported, as
1065 it is not clear exactly what it should do. If you meant to make @array
1066 refer to some other array, use C<\@array = \@other_array>. If you want to
1067 make the elements of @array aliases of the scalars referenced on the
1068 right-hand side, use C<\(@array) = @scalar_refs>.
1070 =item Can't modify reference to parenthesized hash in list assignment
1072 (F) Assigning to C<\(%hash)> is not supported. If you meant to make %hash
1073 refer to some other hash, use C<\%hash = \%other_hash>. If you want to
1074 make the elements of %hash into aliases of the scalars referenced on the
1075 right-hand side, use a hash slice: C<\@hash{@keys} = @those_scalar_refs>.
1077 =item Can't msgrcv to read-only var
1079 (F) The target of a msgrcv must be modifiable to be used as a receive
1082 =item Can't "next" outside a loop block
1084 (F) A "next" statement was executed to reiterate the current block, but
1085 there isn't a current block. Note that an "if" or "else" block doesn't
1086 count as a "loopish" block, as doesn't a block given to sort(), map() or
1087 grep(). You can usually double the curlies to get the same effect
1088 though, because the inner curlies will be considered a block that loops
1089 once. See L<perlfunc/next>.
1091 =item Can't open %s: %s
1093 (S inplace) The implicit opening of a file through use of the C<< <> >>
1094 filehandle, either implicitly under the C<-n> or C<-p> command-line
1095 switches, or explicitly, failed for the indicated reason. Usually
1096 this is because you don't have read permission for a file which
1097 you named on the command line.
1099 (F) You tried to call perl with the B<-e> switch, but F</dev/null> (or
1100 your operating system's equivalent) could not be opened.
1102 =item Can't open a reference
1104 (W io) You tried to open a scalar reference for reading or writing,
1105 using the 3-arg open() syntax:
1109 but your version of perl is compiled without perlio, and this form of
1110 open is not supported.
1112 =item Can't open bidirectional pipe
1114 (W pipe) You tried to say C<open(CMD, "|cmd|")>, which is not supported.
1115 You can try any of several modules in the Perl library to do this, such
1116 as IPC::Open2. Alternately, direct the pipe's output to a file using
1117 ">", and then read it in under a different file handle.
1119 =item Can't open error file %s as stderr
1121 (F) An error peculiar to VMS. Perl does its own command line
1122 redirection, and couldn't open the file specified after '2>' or '2>>' on
1123 the command line for writing.
1125 =item Can't open input file %s as stdin
1127 (F) An error peculiar to VMS. Perl does its own command line
1128 redirection, and couldn't open the file specified after '<' on the
1129 command line for reading.
1131 =item Can't open output file %s as stdout
1133 (F) An error peculiar to VMS. Perl does its own command line
1134 redirection, and couldn't open the file specified after '>' or '>>' on
1135 the command line for writing.
1137 =item Can't open output pipe (name: %s)
1139 (P) An error peculiar to VMS. Perl does its own command line
1140 redirection, and couldn't open the pipe into which to send data destined
1143 =item Can't open perl script "%s": %s
1145 (F) The script you specified can't be opened for the indicated reason.
1147 If you're debugging a script that uses #!, and normally relies on the
1148 shell's $PATH search, the -S option causes perl to do that search, so
1149 you don't have to type the path or C<`which $scriptname`>.
1151 =item Can't read CRTL environ
1153 (S) A warning peculiar to VMS. Perl tried to read an element of %ENV
1154 from the CRTL's internal environment array and discovered the array was
1155 missing. You need to figure out where your CRTL misplaced its environ
1156 or define F<PERL_ENV_TABLES> (see L<perlvms>) so that environ is not
1159 =item Can't "redo" outside a loop block
1161 (F) A "redo" statement was executed to restart the current block, but
1162 there isn't a current block. Note that an "if" or "else" block doesn't
1163 count as a "loopish" block, as doesn't a block given to sort(), map()
1164 or grep(). You can usually double the curlies to get the same effect
1165 though, because the inner curlies will be considered a block that
1166 loops once. See L<perlfunc/redo>.
1168 =item Can't remove %s: %s, skipping file
1170 (S inplace) You requested an inplace edit without creating a backup
1171 file. Perl was unable to remove the original file to replace it with
1172 the modified file. The file was left unmodified.
1174 =item Can't rename %s to %s: %s, skipping file
1176 (S inplace) The rename done by the B<-i> switch failed for some reason,
1177 probably because you don't have write permission to the directory.
1179 =item Can't reopen input pipe (name: %s) in binary mode
1181 (P) An error peculiar to VMS. Perl thought stdin was a pipe, and tried
1182 to reopen it to accept binary data. Alas, it failed.
1184 =item Can't represent character for Ox%X on this platform
1186 (F) There is a hard limit to how big a character code point can be due
1187 to the fundamental properties of UTF-8, especially on EBCDIC
1188 platforms. The given code point exceeds that. The only work-around is
1189 to not use such a large code point.
1191 =item Can't reset %ENV on this system
1193 (F) You called C<reset('E')> or similar, which tried to reset
1194 all variables in the current package beginning with "E". In
1195 the main package, that includes %ENV. Resetting %ENV is not
1196 supported on some systems, notably VMS.
1198 =item Can't resolve method "%s" overloading "%s" in package "%s"
1200 (F)(P) Error resolving overloading specified by a method name (as
1201 opposed to a subroutine reference): no such method callable via the
1202 package. If the method name is C<???>, this is an internal error.
1204 =item Can't return %s from lvalue subroutine
1206 (F) Perl detected an attempt to return illegal lvalues (such as
1207 temporary or readonly values) from a subroutine used as an lvalue. This
1210 =item Can't return outside a subroutine
1212 (F) The return statement was executed in mainline code, that is, where
1213 there was no subroutine call to return out of. See L<perlsub>.
1215 =item Can't return %s to lvalue scalar context
1217 (F) You tried to return a complete array or hash from an lvalue
1218 subroutine, but you called the subroutine in a way that made Perl
1219 think you meant to return only one value. You probably meant to
1220 write parentheses around the call to the subroutine, which tell
1221 Perl that the call should be in list context.
1223 =item Can't stat script "%s"
1225 (P) For some reason you can't fstat() the script even though you have it
1226 open already. Bizarre.
1228 =item Can't take log of %g
1230 (F) For ordinary real numbers, you can't take the logarithm of a
1231 negative number or zero. There's a Math::Complex package that comes
1232 standard with Perl, though, if you really want to do that for the
1235 =item Can't take sqrt of %g
1237 (F) For ordinary real numbers, you can't take the square root of a
1238 negative number. There's a Math::Complex package that comes standard
1239 with Perl, though, if you really want to do that.
1241 =item Can't undef active subroutine
1243 (F) You can't undefine a routine that's currently running. You can,
1244 however, redefine it while it's running, and you can even undef the
1245 redefined subroutine while the old routine is running. Go figure.
1247 =item Can't upgrade %s (%d) to %d
1249 (P) The internal sv_upgrade routine adds "members" to an SV, making it
1250 into a more specialized kind of SV. The top several SV types are so
1251 specialized, however, that they cannot be interconverted. This message
1252 indicates that such a conversion was attempted.
1254 =item Can't use '%c' after -mname
1256 (F) You tried to call perl with the B<-m> switch, but you put something
1257 other than "=" after the module name.
1259 =item Can't use a hash as a reference
1261 (F) You tried to use a hash as a reference, as in
1262 C<< %foo->{"bar"} >> or C<< %$ref->{"hello"} >>. Versions of perl
1263 <= 5.22.0 used to allow this syntax, but shouldn't
1264 have. This was deprecated in perl 5.6.1.
1266 =item Can't use an array as a reference
1268 (F) You tried to use an array as a reference, as in
1269 C<< @foo->[23] >> or C<< @$ref->[99] >>. Versions of perl <= 5.22.0
1270 used to allow this syntax, but shouldn't have. This
1271 was deprecated in perl 5.6.1.
1273 =item Can't use anonymous symbol table for method lookup
1275 (F) The internal routine that does method lookup was handed a symbol
1276 table that doesn't have a name. Symbol tables can become anonymous
1277 for example by undefining stashes: C<undef %Some::Package::>.
1279 =item Can't use an undefined value as %s reference
1281 (F) A value used as either a hard reference or a symbolic reference must
1282 be a defined value. This helps to delurk some insidious errors.
1284 =item Can't use bareword ("%s") as %s ref while "strict refs" in use
1286 (F) Only hard references are allowed by "strict refs". Symbolic
1287 references are disallowed. See L<perlref>.
1289 =item Can't use %! because Errno.pm is not available
1291 (F) The first time the C<%!> hash is used, perl automatically loads the
1292 Errno.pm module. The Errno module is expected to tie the %! hash to
1293 provide symbolic names for C<$!> errno values.
1295 =item Can't use both '<' and '>' after type '%c' in %s
1297 (F) A type cannot be forced to have both big-endian and little-endian
1298 byte-order at the same time, so this combination of modifiers is not
1299 allowed. See L<perlfunc/pack>.
1301 =item Can't use 'defined(@array)' (Maybe you should just omit the defined()?)
1303 (F) defined() is not useful on arrays because it
1304 checks for an undefined I<scalar> value. If you want to see if the
1305 array is empty, just use C<if (@array) { # not empty }> for example.
1307 =item Can't use 'defined(%hash)' (Maybe you should just omit the defined()?)
1309 (F) C<defined()> is not usually right on hashes.
1311 Although C<defined %hash> is false on a plain not-yet-used hash, it
1312 becomes true in several non-obvious circumstances, including iterators,
1313 weak references, stash names, even remaining true after C<undef %hash>.
1314 These things make C<defined %hash> fairly useless in practice, so it now
1315 generates a fatal error.
1317 If a check for non-empty is what you wanted then just put it in boolean
1318 context (see L<perldata/Scalar values>):
1324 If you had C<defined %Foo::Bar::QUUX> to check whether such a package
1325 variable exists then that's never really been reliable, and isn't
1326 a good way to enquire about the features of a package, or whether
1329 =item Can't use %s for loop variable
1331 (F) Only a simple scalar variable may be used as a loop variable on a
1334 =item Can't use global %s in "%s"
1336 (F) You tried to declare a magical variable as a lexical variable. This
1337 is not allowed, because the magic can be tied to only one location
1338 (namely the global variable) and it would be incredibly confusing to
1339 have variables in your program that looked like magical variables but
1342 =item Can't use '%c' in a group with different byte-order in %s
1344 (F) You attempted to force a different byte-order on a type
1345 that is already inside a group with a byte-order modifier.
1346 For example you cannot force little-endianness on a type that
1347 is inside a big-endian group.
1349 =item Can't use "my %s" in sort comparison
1351 (F) The global variables $a and $b are reserved for sort comparisons.
1352 You mentioned $a or $b in the same line as the <=> or cmp operator,
1353 and the variable had earlier been declared as a lexical variable.
1354 Either qualify the sort variable with the package name, or rename the
1357 =item Can't use %s ref as %s ref
1359 (F) You've mixed up your reference types. You have to dereference a
1360 reference of the type needed. You can use the ref() function to
1361 test the type of the reference, if need be.
1363 =item Can't use string ("%s") as %s ref while "strict refs" in use
1365 =item Can't use string ("%s"...) as %s ref while "strict refs" in use
1367 (F) You've told Perl to dereference a string, something which
1368 C<use strict> blocks to prevent it happening accidentally. See
1369 L<perlref/"Symbolic references">. This can be triggered by an C<@> or C<$>
1370 in a double-quoted string immediately before interpolating a variable,
1371 for example in C<"user @$twitter_id">, which says to treat the contents
1372 of C<$twitter_id> as an array reference; use a C<\> to have a literal C<@>
1373 symbol followed by the contents of C<$twitter_id>: C<"user \@$twitter_id">.
1375 =item Can't use subscript on %s
1377 (F) The compiler tried to interpret a bracketed expression as a
1378 subscript. But to the left of the brackets was an expression that
1379 didn't look like a hash or array reference, or anything else subscriptable.
1381 =item Can't use \%c to mean $%c in expression
1383 (W syntax) In an ordinary expression, backslash is a unary operator that
1384 creates a reference to its argument. The use of backslash to indicate a
1385 backreference to a matched substring is valid only as part of a regular
1386 expression pattern. Trying to do this in ordinary Perl code produces a
1387 value that prints out looking like SCALAR(0xdecaf). Use the $1 form
1390 =item Can't weaken a nonreference
1392 (F) You attempted to weaken something that was not a reference. Only
1393 references can be weakened.
1395 =item Can't "when" outside a topicalizer
1397 (F) You have used a when() block that is neither inside a C<foreach>
1398 loop nor a C<given> block. (Note that this error is issued on exit
1399 from the C<when> block, so you won't get the error if the match fails,
1400 or if you use an explicit C<continue>.)
1402 =item Can't x= to read-only value
1404 (F) You tried to repeat a constant value (often the undefined value)
1405 with an assignment operator, which implies modifying the value itself.
1406 Perhaps you need to copy the value to a temporary, and repeat that.
1408 =item Character following "\c" must be printable ASCII
1410 (F) In C<\cI<X>>, I<X> must be a printable (non-control) ASCII character.
1412 Note that ASCII characters that don't map to control characters are
1413 discouraged, and will generate the warning (when enabled)
1414 L</""\c%c" is more clearly written simply as "%s"">.
1416 =item Character in 'C' format wrapped in pack
1422 where $x is either less than 0 or more than 255; the C<"C"> format is
1423 only for encoding native operating system characters (ASCII, EBCDIC,
1424 and so on) and not for Unicode characters, so Perl behaved as if you meant
1428 If you actually want to pack Unicode codepoints, use the C<"U"> format
1431 =item Character in 'c' format wrapped in pack
1437 where $x is either less than -128 or more than 127; the C<"c"> format
1438 is only for encoding native operating system characters (ASCII, EBCDIC,
1439 and so on) and not for Unicode characters, so Perl behaved as if you meant
1441 pack("c", $x & 255);
1443 If you actually want to pack Unicode codepoints, use the C<"U"> format
1446 =item Character in '%c' format wrapped in unpack
1448 (W unpack) You tried something like
1450 unpack("H", "\x{2a1}")
1452 where the format expects to process a byte (a character with a value
1453 below 256), but a higher value was provided instead. Perl uses the
1454 value modulus 256 instead, as if you had provided:
1456 unpack("H", "\x{a1}")
1458 =item Character in 'W' format wrapped in pack
1464 where $x is either less than 0 or more than 255. However, C<U0>-mode
1465 expects all values to fall in the interval [0, 255], so Perl behaved
1468 pack("U0W", $x & 255)
1470 =item Character(s) in '%c' format wrapped in pack
1472 (W pack) You tried something like
1474 pack("u", "\x{1f3}b")
1476 where the format expects to process a sequence of bytes (character with a
1477 value below 256), but some of the characters had a higher value. Perl
1478 uses the character values modulus 256 instead, as if you had provided:
1480 pack("u", "\x{f3}b")
1482 =item Character(s) in '%c' format wrapped in unpack
1484 (W unpack) You tried something like
1486 unpack("s", "\x{1f3}b")
1488 where the format expects to process a sequence of bytes (character with a
1489 value below 256), but some of the characters had a higher value. Perl
1490 uses the character values modulus 256 instead, as if you had provided:
1492 unpack("s", "\x{f3}b")
1494 =item charnames alias definitions may not contain a sequence of multiple spaces
1496 (F) You defined a character name which had multiple space characters
1497 in a row. Change them to single spaces. Usually these names are
1498 defined in the C<:alias> import argument to C<use charnames>, but they
1499 could be defined by a translator installed into C<$^H{charnames}>. See
1500 L<charnames/CUSTOM ALIASES>.
1502 =item charnames alias definitions may not contain trailing white-space
1504 (F) You defined a character name which ended in a space
1505 character. Remove the trailing space(s). Usually these names are
1506 defined in the C<:alias> import argument to C<use charnames>, but they
1507 could be defined by a translator installed into C<$^H{charnames}>.
1508 See L<charnames/CUSTOM ALIASES>.
1510 =item \C is deprecated in regex; marked by <-- HERE in m/%s/
1512 (D deprecated, regexp) The \C character class is deprecated, and will
1513 become a compile-time error in a future release of perl (tentatively
1514 v5.24). This construct allows you to match a single byte of what makes
1515 up a multi-byte single UTF8 character, and breaks encapsulation. It is
1516 currently also very buggy. If you really need to process the individual
1517 bytes, you probably want to convert your string to one where each
1518 underlying byte is stored as a character, with utf8::encode().
1520 =item "\c%c" is more clearly written simply as "%s"
1522 (W syntax) The C<\cI<X>> construct is intended to be a way to specify
1523 non-printable characters. You used it for a printable one, which
1524 is better written as simply itself, perhaps preceded by a backslash
1525 for non-word characters. Doing it the way you did is not portable
1526 between ASCII and EBCDIC platforms.
1528 =item Cloning substitution context is unimplemented
1530 (F) Creating a new thread inside the C<s///> operator is not supported.
1532 =item closedir() attempted on invalid dirhandle %s
1534 (W io) The dirhandle you tried to close is either closed or not really
1535 a dirhandle. Check your control flow.
1537 =item close() on unopened filehandle %s
1539 (W unopened) You tried to close a filehandle that was never opened.
1541 =item Closure prototype called
1543 (F) If a closure has attributes, the subroutine passed to an attribute
1544 handler is the prototype that is cloned when a new closure is created.
1545 This subroutine cannot be called.
1547 =item Code missing after '/'
1549 (F) You had a (sub-)template that ends with a '/'. There must be
1550 another template code following the slash. See L<perlfunc/pack>.
1552 =item Code point 0x%X is not Unicode, may not be portable
1554 (S non_unicode) You had a code point above the Unicode maximum
1557 Perl allows strings to contain a superset of Unicode code points, up
1558 to the limit of what is storable in an unsigned integer on your system,
1559 but these may not be accepted by other languages/systems. At one time,
1560 it was legal in some standards to have code points up to 0x7FFF_FFFF,
1561 but not higher. Code points above 0xFFFF_FFFF require larger than a
1564 =item %s: Command not found
1566 (A) You've accidentally run your script through B<csh> or another shell
1567 instead of Perl. Check the #! line, or manually feed your script into
1568 Perl yourself. The #! line at the top of your file could look like
1572 =item Compilation failed in require
1574 (F) Perl could not compile a file specified in a C<require> statement.
1575 Perl uses this generic message when none of the errors that it
1576 encountered were severe enough to halt compilation immediately.
1578 =item Complex regular subexpression recursion limit (%d) exceeded
1580 (W regexp) The regular expression engine uses recursion in complex
1581 situations where back-tracking is required. Recursion depth is limited
1582 to 32766, or perhaps less in architectures where the stack cannot grow
1583 arbitrarily. ("Simple" and "medium" situations are handled without
1584 recursion and are not subject to a limit.) Try shortening the string
1585 under examination; looping in Perl code (e.g. with C<while>) rather than
1586 in the regular expression engine; or rewriting the regular expression so
1587 that it is simpler or backtracks less. (See L<perlfaq2> for information
1588 on I<Mastering Regular Expressions>.)
1590 =item connect() on closed socket %s
1592 (W closed) You tried to do a connect on a closed socket. Did you forget
1593 to check the return value of your socket() call? See
1594 L<perlfunc/connect>.
1596 =item Constant(%s): Call to &{$^H{%s}} did not return a defined value
1598 (F) The subroutine registered to handle constant overloading
1599 (see L<overload>) or a custom charnames handler (see
1600 L<charnames/CUSTOM TRANSLATORS>) returned an undefined value.
1602 =item Constant(%s): $^H{%s} is not defined
1604 (F) The parser found inconsistencies while attempting to define an
1605 overloaded constant. Perhaps you forgot to load the corresponding
1608 =item Constant is not %s reference
1610 (F) A constant value (perhaps declared using the C<use constant> pragma)
1611 is being dereferenced, but it amounts to the wrong type of reference.
1612 The message indicates the type of reference that was expected. This
1613 usually indicates a syntax error in dereferencing the constant value.
1614 See L<perlsub/"Constant Functions"> and L<constant>.
1616 =item Constant subroutine %s redefined
1618 (W redefine)(S) You redefined a subroutine which had previously
1619 been eligible for inlining. See L<perlsub/"Constant Functions">
1620 for commentary and workarounds.
1622 =item Constant subroutine %s undefined
1624 (W misc) You undefined a subroutine which had previously been eligible
1625 for inlining. See L<perlsub/"Constant Functions"> for commentary and
1628 =item Constant(%s) unknown
1630 (F) The parser found inconsistencies either while attempting
1631 to define an overloaded constant, or when trying to find the
1632 character name specified in the C<\N{...}> escape. Perhaps you
1633 forgot to load the corresponding L<overload> pragma?.
1635 =item Copy method did not return a reference
1637 (F) The method which overloads "=" is buggy. See
1638 L<overload/Copy Constructor>.
1640 =item &CORE::%s cannot be called directly
1642 (F) You tried to call a subroutine in the C<CORE::> namespace
1643 with C<&foo> syntax or through a reference. Some subroutines
1644 in this package cannot yet be called that way, but must be
1645 called as barewords. Something like this will work:
1647 BEGIN { *shove = \&CORE::push; }
1648 shove @array, 1,2,3; # pushes on to @array
1650 =item CORE::%s is not a keyword
1652 (F) The CORE:: namespace is reserved for Perl keywords.
1654 =item Corrupted regexp opcode %d > %d
1656 (P) This is either an error in Perl, or, if you're using
1657 one, your L<custom regular expression engine|perlreapi>. If not the
1658 latter, report the problem through the L<perlbug> utility.
1660 =item corrupted regexp pointers
1662 (P) The regular expression engine got confused by what the regular
1663 expression compiler gave it.
1665 =item corrupted regexp program
1667 (P) The regular expression engine got passed a regexp program without a
1670 =item Corrupt malloc ptr 0x%x at 0x%x
1672 (P) The malloc package that comes with Perl had an internal failure.
1674 =item Count after length/code in unpack
1676 (F) You had an unpack template indicating a counted-length string, but
1677 you have also specified an explicit size for the string. See
1681 The following are used in lib/diagnostics.t for testing two =items that
1682 share the same description. Changes here need to be propagated to there
1684 =item Deep recursion on anonymous subroutine
1686 =item Deep recursion on subroutine "%s"
1688 (W recursion) This subroutine has called itself (directly or indirectly)
1689 100 times more than it has returned. This probably indicates an
1690 infinite recursion, unless you're writing strange benchmark programs, in
1691 which case it indicates something else.
1693 This threshold can be changed from 100, by recompiling the F<perl> binary,
1694 setting the C pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value.
1696 =item (?(DEFINE)....) does not allow branches in regex; marked by
1697 S<<-- HERE> in m/%s/
1699 (F) You used something like C<(?(DEFINE)...|..)> which is illegal. The
1700 most likely cause of this error is that you left out a parenthesis inside
1701 of the C<....> part.
1703 The <-- HERE shows whereabouts in the regular expression the problem was
1706 =item %s defines neither package nor VERSION--version check failed
1708 (F) You said something like "use Module 42" but in the Module file
1709 there are neither package declarations nor a C<$VERSION>.
1711 =item delete argument is index/value array slice, use array slice
1713 (F) You used index/value array slice syntax (C<%array[...]>) as
1714 the argument to C<delete>. You probably meant C<@array[...]> with
1715 an @ symbol instead.
1717 =item delete argument is key/value hash slice, use hash slice
1719 (F) You used key/value hash slice syntax (C<%hash{...}>) as the argument to
1720 C<delete>. You probably meant C<@hash{...}> with an @ symbol instead.
1722 =item delete argument is not a HASH or ARRAY element or slice
1724 (F) The argument to C<delete> must be either a hash or array element,
1730 or a hash or array slice, such as:
1732 @foo[$bar, $baz, $xyzzy]
1733 @{$ref->[12]}{"susie", "queue"}
1735 =item Delimiter for here document is too long
1737 (F) In a here document construct like C<<<FOO>, the label C<FOO> is too
1738 long for Perl to handle. You have to be seriously twisted to write code
1739 that triggers this error.
1741 =item Deprecated use of my() in false conditional
1743 (D deprecated) You used a declaration similar to C<my $x if 0>. There
1744 has been a long-standing bug in Perl that causes a lexical variable
1745 not to be cleared at scope exit when its declaration includes a false
1746 conditional. Some people have exploited this bug to achieve a kind of
1747 static variable. Since we intend to fix this bug, we don't want people
1748 relying on this behavior. You can achieve a similar static effect by
1749 declaring the variable in a separate block outside the function, eg
1751 sub f { my $x if 0; return $x++ }
1755 { my $x; sub f { return $x++ } }
1757 Beginning with perl 5.10.0, you can also use C<state> variables to have
1758 lexicals that are initialized only once (see L<feature>):
1760 sub f { state $x; return $x++ }
1762 =item DESTROY created new reference to dead object '%s'
1764 (F) A DESTROY() method created a new reference to the object which is
1765 just being DESTROYed. Perl is confused, and prefers to abort rather
1766 than to create a dangling reference.
1768 =item Did not produce a valid header
1772 =item %s did not return a true value
1774 (F) A required (or used) file must return a true value to indicate that
1775 it compiled correctly and ran its initialization code correctly. It's
1776 traditional to end such a file with a "1;", though any true value would
1777 do. See L<perlfunc/require>.
1779 =item (Did you mean &%s instead?)
1781 (W misc) You probably referred to an imported subroutine &FOO as $FOO or
1784 =item (Did you mean "local" instead of "our"?)
1786 (W misc) Remember that "our" does not localize the declared global
1787 variable. You have declared it again in the same lexical scope, which
1790 =item (Did you mean $ or @ instead of %?)
1792 (W) You probably said %hash{$key} when you meant $hash{$key} or
1793 @hash{@keys}. On the other hand, maybe you just meant %hash and got
1798 (F) You passed die() an empty string (the equivalent of C<die "">) or
1799 you called it with no args and C<$@> was empty.
1801 =item Document contains no data
1805 =item %s does not define %s::VERSION--version check failed
1807 (F) You said something like "use Module 42" but the Module did not
1808 define a C<$VERSION>.
1810 =item '/' does not take a repeat count
1812 (F) You cannot put a repeat count of any kind right after the '/' code.
1813 See L<perlfunc/pack>.
1815 =item Don't know how to get file name
1817 (P) C<PerlIO_getname>, a perl internal I/O function specific to VMS, was
1818 somehow called on another platform. This should not happen.
1820 =item Don't know how to handle magic of type \%o
1822 (P) The internal handling of magical variables has been cursed.
1824 =item do_study: out of memory
1826 (P) This should have been caught by safemalloc() instead.
1828 =item (Do you need to predeclare %s?)
1830 (S syntax) This is an educated guess made in conjunction with the message
1831 "%s found where operator expected". It often means a subroutine or module
1832 name is being referenced that hasn't been declared yet. This may be
1833 because of ordering problems in your file, or because of a missing
1834 "sub", "package", "require", or "use" statement. If you're referencing
1835 something that isn't defined yet, you don't actually have to define the
1836 subroutine or package before the current location. You can use an empty
1837 "sub foo;" or "package FOO;" to enter a "forward" declaration.
1839 =item dump() better written as CORE::dump()
1841 (W misc) You used the obsolescent C<dump()> built-in function, without fully
1842 qualifying it as C<CORE::dump()>. Maybe it's a typo. See L<perlfunc/dump>.
1844 =item dump is not supported
1846 (F) Your machine doesn't support dump/undump.
1848 =item Duplicate free() ignored
1850 (S malloc) An internal routine called free() on something that had
1853 =item Duplicate modifier '%c' after '%c' in %s
1855 (W unpack) You have applied the same modifier more than once after a
1856 type in a pack template. See L<perlfunc/pack>.
1858 =item each on reference is experimental
1860 (S experimental::autoderef) C<each> with a scalar argument is experimental
1861 and may change or be removed in a future Perl version. If you want to
1862 take the risk of using this feature, simply disable this warning:
1864 no warnings "experimental::autoderef";
1866 =item elseif should be elsif
1868 (S syntax) There is no keyword "elseif" in Perl because Larry thinks
1869 it's ugly. Your code will be interpreted as an attempt to call a method
1870 named "elseif" for the class returned by the following block. This is
1871 unlikely to be what you want.
1873 =item Empty \%c{} in regex; marked by S<<-- HERE> in m/%s/
1875 (F) C<\p> and C<\P> are used to introduce a named Unicode property, as
1876 described in L<perlunicode> and L<perlre>. You used C<\p> or C<\P> in
1877 a regular expression without specifying the property name.
1879 =item entering effective %s failed
1881 (F) While under the C<use filetest> pragma, switching the real and
1882 effective uids or gids failed.
1884 =item %ENV is aliased to %s
1886 (F) You're running under taint mode, and the C<%ENV> variable has been
1887 aliased to another hash, so it doesn't reflect anymore the state of the
1888 program's environment. This is potentially insecure.
1890 =item Error converting file specification %s
1892 (F) An error peculiar to VMS. Because Perl may have to deal with file
1893 specifications in either VMS or Unix syntax, it converts them to a
1894 single form when it must operate on them directly. Either you've passed
1895 an invalid file specification to Perl, or you've found a case the
1896 conversion routines don't handle. Drat.
1898 =item Eval-group in insecure regular expression
1900 (F) Perl detected tainted data when trying to compile a regular
1901 expression that contains the C<(?{ ... })> zero-width assertion, which
1902 is unsafe. See L<perlre/(?{ code })>, and L<perlsec>.
1904 =item Eval-group not allowed at runtime, use re 'eval' in regex m/%s/
1906 (F) Perl tried to compile a regular expression containing the
1907 C<(?{ ... })> zero-width assertion at run time, as it would when the
1908 pattern contains interpolated values. Since that is a security risk,
1909 it is not allowed. If you insist, you may still do this by using the
1910 C<re 'eval'> pragma or by explicitly building the pattern from an
1911 interpolated string at run time and using that in an eval(). See
1912 L<perlre/(?{ code })>.
1914 =item Eval-group not allowed, use re 'eval' in regex m/%s/
1916 (F) A regular expression contained the C<(?{ ... })> zero-width
1917 assertion, but that construct is only allowed when the C<use re 'eval'>
1918 pragma is in effect. See L<perlre/(?{ code })>.
1920 =item EVAL without pos change exceeded limit in regex; marked by
1921 S<<-- HERE> in m/%s/
1923 (F) You used a pattern that nested too many EVAL calls without consuming
1924 any text. Restructure the pattern so that text is consumed.
1926 The <-- HERE shows whereabouts in the regular expression the problem was
1929 =item Excessively long <> operator
1931 (F) The contents of a <> operator may not exceed the maximum size of a
1932 Perl identifier. If you're just trying to glob a long list of
1933 filenames, try using the glob() operator, or put the filenames into a
1934 variable and glob that.
1936 =item exec? I'm not *that* kind of operating system
1938 (F) The C<exec> function is not implemented on some systems, e.g., Symbian
1939 OS. See L<perlport>.
1941 =item Execution of %s aborted due to compilation errors.
1943 (F) The final summary message when a Perl compilation fails.
1945 =item exists argument is not a HASH or ARRAY element or a subroutine
1947 (F) The argument to C<exists> must be a hash or array element or a
1948 subroutine with an ampersand, such as:
1954 =item exists argument is not a subroutine name
1956 (F) The argument to C<exists> for C<exists &sub> must be a subroutine name,
1957 and not a subroutine call. C<exists &sub()> will generate this error.
1959 =item Exiting eval via %s
1961 (W exiting) You are exiting an eval by unconventional means, such as a
1962 goto, or a loop control statement.
1964 =item Exiting format via %s
1966 (W exiting) You are exiting a format by unconventional means, such as a
1967 goto, or a loop control statement.
1969 =item Exiting pseudo-block via %s
1971 (W exiting) You are exiting a rather special block construct (like a
1972 sort block or subroutine) by unconventional means, such as a goto, or a
1973 loop control statement. See L<perlfunc/sort>.
1975 =item Exiting subroutine via %s
1977 (W exiting) You are exiting a subroutine by unconventional means, such
1978 as a goto, or a loop control statement.
1980 =item Exiting substitution via %s
1982 (W exiting) You are exiting a substitution by unconventional means, such
1983 as a return, a goto, or a loop control statement.
1985 =item Expecting close bracket in regex; marked by S<<-- HERE> in m/%s/
1987 (F) You wrote something like
1991 to denote a capturing group of the form
1992 L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>,
1993 but omitted the C<")">.
1995 =item Expecting '(?flags:(?[...' in regex; marked by S<<-- HERE> in m/%s/
1997 (F) The C<(?[...])> extended character class regular expression construct
1998 only allows character classes (including character class escapes like
1999 C<\d>), operators, and parentheses. The one exception is C<(?flags:...)>
2000 containing at least one flag and exactly one C<(?[...])> construct.
2001 This allows a regular expression containing just C<(?[...])> to be
2002 interpolated. If you see this error message, then you probably
2003 have some other C<(?...)> construct inside your character class. See
2004 L<perlrecharclass/Extended Bracketed Character Classes>.
2006 =item Experimental aliasing via reference not enabled
2008 (F) To do aliasing via references, you must first enable the feature:
2010 no warnings "experimental::refaliasing";
2011 use feature "refaliasing";
2014 =item Experimental subroutine signatures not enabled
2016 (F) To use subroutine signatures, you must first enable them:
2018 no warnings "experimental::signatures";
2019 use feature "signatures";
2020 sub foo ($left, $right) { ... }
2022 =item Experimental "%s" subs not enabled
2024 (F) To use lexical subs, you must first enable them:
2026 no warnings 'experimental::lexical_subs';
2027 use feature 'lexical_subs';
2030 =item Explicit blessing to '' (assuming package main)
2032 (W misc) You are blessing a reference to a zero length string. This has
2033 the effect of blessing the reference into the package main. This is
2034 usually not what you want. Consider providing a default target package,
2035 e.g. bless($ref, $p || 'MyPackage');
2037 =item %s: Expression syntax
2039 (A) You've accidentally run your script through B<csh> instead of Perl.
2040 Check the #! line, or manually feed your script into Perl yourself.
2042 =item %s failed--call queue aborted
2044 (F) An untrapped exception was raised while executing a UNITCHECK,
2045 CHECK, INIT, or END subroutine. Processing of the remainder of the
2046 queue of such routines has been prematurely ended.
2048 =item False [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
2050 (W regexp)(F) A character class range must start and end at a literal
2051 character, not another character class like C<\d> or C<[:alpha:]>. The "-"
2052 in your false range is interpreted as a literal "-". In a C<(?[...])>
2053 construct, this is an error, rather than a warning. Consider quoting
2054 the "-", "\-". The S<<-- HERE> shows whereabouts in the regular expression
2055 the problem was discovered. See L<perlre>.
2057 =item Fatal VMS error (status=%d) at %s, line %d
2059 (P) An error peculiar to VMS. Something untoward happened in a VMS
2060 system service or RTL routine; Perl's exit status should provide more
2061 details. The filename in "at %s" and the line number in "line %d" tell
2062 you which section of the Perl source code is distressed.
2064 =item fcntl is not implemented
2066 (F) Your machine apparently doesn't implement fcntl(). What is this, a
2067 PDP-11 or something?
2069 =item FETCHSIZE returned a negative value
2071 (F) A tied array claimed to have a negative number of elements, which
2074 =item Field too wide in 'u' format in pack
2076 (W pack) Each line in an uuencoded string starts with a length indicator
2077 which can't encode values above 63. So there is no point in asking for
2078 a line length bigger than that. Perl will behave as if you specified
2079 C<u63> as the format.
2081 =item Filehandle %s opened only for input
2083 (W io) You tried to write on a read-only filehandle. If you intended
2084 it to be a read-write filehandle, you needed to open it with "+<" or
2085 "+>" or "+>>" instead of with "<" or nothing. If you intended only to
2086 write the file, use ">" or ">>". See L<perlfunc/open>.
2088 =item Filehandle %s opened only for output
2090 (W io) You tried to read from a filehandle opened only for writing, If
2091 you intended it to be a read/write filehandle, you needed to open it
2092 with "+<" or "+>" or "+>>" instead of with ">". If you intended only to
2093 read from the file, use "<". See L<perlfunc/open>. Another possibility
2094 is that you attempted to open filedescriptor 0 (also known as STDIN) for
2095 output (maybe you closed STDIN earlier?).
2097 =item Filehandle %s reopened as %s only for input
2099 (W io) You opened for reading a filehandle that got the same filehandle id
2100 as STDOUT or STDERR. This occurred because you closed STDOUT or STDERR
2103 =item Filehandle STDIN reopened as %s only for output
2105 (W io) You opened for writing a filehandle that got the same filehandle id
2106 as STDIN. This occurred because you closed STDIN previously.
2108 =item Final $ should be \$ or $name
2110 (F) You must now decide whether the final $ in a string was meant to be
2111 a literal dollar sign, or was meant to introduce a variable name that
2112 happens to be missing. So you have to put either the backslash or the
2115 =item flock() on closed filehandle %s
2117 (W closed) The filehandle you're attempting to flock() got itself closed
2118 some time before now. Check your control flow. flock() operates on
2119 filehandles. Are you attempting to call flock() on a dirhandle by the
2122 =item Format not terminated
2124 (F) A format must be terminated by a line with a solitary dot. Perl got
2125 to the end of your file without finding such a line.
2127 =item Format %s redefined
2129 (W redefine) You redefined a format. To suppress this warning, say
2132 no warnings 'redefine';
2133 eval "format NAME =...";
2136 =item Found = in conditional, should be ==
2146 (or something like that).
2148 =item %s found where operator expected
2150 (S syntax) The Perl lexer knows whether to expect a term or an operator.
2151 If it sees what it knows to be a term when it was expecting to see an
2152 operator, it gives you this warning. Usually it indicates that an
2153 operator or delimiter was omitted, such as a semicolon.
2155 =item gdbm store returned %d, errno %d, key "%s"
2157 (S) A warning from the GDBM_File extension that a store failed.
2159 =item gethostent not implemented
2161 (F) Your C library apparently doesn't implement gethostent(), probably
2162 because if it did, it'd feel morally obligated to return every hostname
2165 =item get%sname() on closed socket %s
2167 (W closed) You tried to get a socket or peer socket name on a closed
2168 socket. Did you forget to check the return value of your socket() call?
2170 =item getpwnam returned invalid UIC %#o for user "%s"
2172 (S) A warning peculiar to VMS. The call to C<sys$getuai> underlying the
2173 C<getpwnam> operator returned an invalid UIC.
2175 =item getsockopt() on closed socket %s
2177 (W closed) You tried to get a socket option on a closed socket. Did you
2178 forget to check the return value of your socket() call? See
2179 L<perlfunc/getsockopt>.
2181 =item given is experimental
2183 (S experimental::smartmatch) C<given> depends on smartmatch, which
2184 is experimental, so its behavior may change or even be removed
2185 in any future release of perl. See the explanation under
2186 L<perlsyn/Experimental Details on given and when>.
2188 =item Global symbol "%s" requires explicit package name (did you forget to
2191 (F) You've said "use strict" or "use strict vars", which indicates
2192 that all variables must either be lexically scoped (using "my" or "state"),
2193 declared beforehand using "our", or explicitly qualified to say
2194 which package the global variable is in (using "::").
2196 =item glob failed (%s)
2198 (S glob) Something went wrong with the external program(s) used
2199 for C<glob> and C<< <*.c> >>. Usually, this means that you supplied a C<glob>
2200 pattern that caused the external program to fail and exit with a
2201 nonzero status. If the message indicates that the abnormal exit
2202 resulted in a coredump, this may also mean that your csh (C shell)
2203 is broken. If so, you should change all of the csh-related variables
2204 in config.sh: If you have tcsh, make the variables refer to it as
2205 if it were csh (e.g. C<full_csh='/usr/bin/tcsh'>); otherwise, make them
2206 all empty (except that C<d_csh> should be C<'undef'>) so that Perl will
2207 think csh is missing. In either case, after editing config.sh, run
2208 C<./Configure -S> and rebuild Perl.
2210 =item Glob not terminated
2212 (F) The lexer saw a left angle bracket in a place where it was expecting
2213 a term, so it's looking for the corresponding right angle bracket, and
2214 not finding it. Chances are you left some needed parentheses out
2215 earlier in the line, and you really meant a "less than".
2217 =item gmtime(%f) failed
2219 (W overflow) You called C<gmtime> with a number that it could not handle:
2220 too large, too small, or NaN. The returned value is C<undef>.
2222 =item gmtime(%f) too large
2224 (W overflow) You called C<gmtime> with a number that was larger than
2225 it can reliably handle and C<gmtime> probably returned the wrong
2226 date. This warning is also triggered with NaN (the special
2227 not-a-number value).
2229 =item gmtime(%f) too small
2231 (W overflow) You called C<gmtime> with a number that was smaller than
2232 it can reliably handle and C<gmtime> probably returned the wrong date.
2234 =item Got an error from DosAllocMem
2236 (P) An error peculiar to OS/2. Most probably you're using an obsolete
2237 version of Perl, and this should not happen anyway.
2239 =item goto must have label
2241 (F) Unlike with "next" or "last", you're not allowed to goto an
2242 unspecified destination. See L<perlfunc/goto>.
2244 =item Goto undefined subroutine%s
2246 (F) You tried to call a subroutine with C<goto &sub> syntax, but
2247 the indicated subroutine hasn't been defined, or if it was, it
2248 has since been undefined.
2250 =item Group name must start with a non-digit word character in regex; marked by
2251 S<<-- HERE> in m/%s/
2253 (F) Group names must follow the rules for perl identifiers, meaning
2254 they must start with a non-digit word character. A common cause of
2255 this error is using (?&0) instead of (?0). See L<perlre>.
2257 =item ()-group starts with a count
2259 (F) A ()-group started with a count. A count is supposed to follow
2260 something: a template character or a ()-group. See L<perlfunc/pack>.
2262 =item %s had compilation errors.
2264 (F) The final summary message when a C<perl -c> fails.
2266 =item Had to create %s unexpectedly
2268 (S internal) A routine asked for a symbol from a symbol table that ought
2269 to have existed already, but for some reason it didn't, and had to be
2270 created on an emergency basis to prevent a core dump.
2272 =item %s has too many errors
2274 (F) The parser has given up trying to parse the program after 10 errors.
2275 Further error messages would likely be uninformative.
2277 =item Having more than one /%c regexp modifier is deprecated
2279 (D deprecated, regexp) You used the indicated regular expression pattern
2280 modifier at least twice in a string of modifiers. It is deprecated to
2281 do this with this particular modifier, to allow future extensions to the
2284 =item Hexadecimal float: exponent overflow
2286 (W overflow) The hexadecimal floating point has a larger exponent
2287 than the floating point supports.
2289 =item Hexadecimal float: exponent underflow
2291 (W overflow) The hexadecimal floating point has a smaller exponent
2292 than the floating point supports.
2294 =item Hexadecimal float: internal error
2296 (F) Something went horribly bad in hexadecimal float handling.
2298 =item Hexadecimal float: mantissa overflow
2300 (W overflow) The hexadecimal floating point literal had more bits in
2301 the mantissa (the part between the 0x and the exponent, also known as
2302 the fraction or the significand) than the floating point supports.
2304 =item Hexadecimal float: precision loss
2306 (W overflow) The hexadecimal floating point had internally more
2307 digits than could be output. This can be caused by unsupported
2308 long double formats, or by 64-bit integers not being available
2309 (needed to retrieve the digits under some configurations).
2311 =item Hexadecimal float: unsupported long double format
2313 (F) You have configured Perl to use long doubles but
2314 the internals of the long double format are unknown;
2315 therefore the hexadecimal float output is impossible.
2317 =item Hexadecimal number > 0xffffffff non-portable
2319 (W portable) The hexadecimal number you specified is larger than 2**32-1
2320 (4294967295) and therefore non-portable between systems. See
2321 L<perlport> for more on portability concerns.
2323 =item Identifier too long
2325 (F) Perl limits identifiers (names for variables, functions, etc.) to
2326 about 250 characters for simple names, and somewhat more for compound
2327 names (like C<$A::B>). You've exceeded Perl's limits. Future versions
2328 of Perl are likely to eliminate these arbitrary limitations.
2330 =item Ignoring zero length \N{} in character class in regex; marked by
2331 S<<-- HERE> in m/%s/
2333 (W regexp) Named Unicode character escapes (C<\N{...}>) may return a
2334 zero-length sequence. When such an escape is used in a character class
2335 its behaviour is not well defined. Check that the correct escape has
2336 been used, and the correct charname handler is in scope.
2338 =item Illegal binary digit %s
2340 (F) You used a digit other than 0 or 1 in a binary number.
2342 =item Illegal binary digit %s ignored
2344 (W digit) You may have tried to use a digit other than 0 or 1 in a
2345 binary number. Interpretation of the binary number stopped before the
2348 =item Illegal character after '_' in prototype for %s : %s
2350 (W illegalproto) An illegal character was found in a prototype
2351 declaration. The '_' in a prototype must be followed by a ';',
2352 indicating the rest of the parameters are optional, or one of '@'
2353 or '%', since those two will accept 0 or more final parameters.
2355 =item Illegal character \%o (carriage return)
2357 (F) Perl normally treats carriage returns in the program text as it
2358 would any other whitespace, which means you should never see this error
2359 when Perl was built using standard options. For some reason, your
2360 version of Perl appears to have been built without this support. Talk
2361 to your Perl administrator.
2363 =item Illegal character in prototype for %s : %s
2365 (W illegalproto) An illegal character was found in a prototype declaration.
2366 Legal characters in prototypes are $, @, %, *, ;, [, ], &, \, and +.
2367 Perhaps you were trying to write a subroutine signature but didn't enable
2368 that feature first (C<use feature 'signatures'>), so your signature was
2369 instead interpreted as a bad prototype.
2371 =item Illegal declaration of anonymous subroutine
2373 (F) When using the C<sub> keyword to construct an anonymous subroutine,
2374 you must always specify a block of code. See L<perlsub>.
2376 =item Illegal declaration of subroutine %s
2378 (F) A subroutine was not declared correctly. See L<perlsub>.
2380 =item Illegal division by zero
2382 (F) You tried to divide a number by 0. Either something was wrong in
2383 your logic, or you need to put a conditional in to guard against
2386 =item Illegal hexadecimal digit %s ignored
2388 (W digit) You may have tried to use a character other than 0 - 9 or
2389 A - F, a - f in a hexadecimal number. Interpretation of the hexadecimal
2390 number stopped before the illegal character.
2392 =item Illegal modulus zero
2394 (F) You tried to divide a number by 0 to get the remainder. Most
2395 numbers don't take to this kindly.
2397 =item Illegal number of bits in vec
2399 (F) The number of bits in vec() (the third argument) must be a power of
2400 two from 1 to 32 (or 64, if your platform supports that).
2402 =item Illegal octal digit %s
2404 (F) You used an 8 or 9 in an octal number.
2406 =item Illegal octal digit %s ignored
2408 (W digit) You may have tried to use an 8 or 9 in an octal number.
2409 Interpretation of the octal number stopped before the 8 or 9.
2411 =item Illegal pattern in regex; marked by S<<-- HERE> in m/%s/
2413 (F) You wrote something like
2417 The C<"+"> is valid only when followed by digits, indicating a
2418 capturing group. See
2419 L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>.
2421 =item Illegal suidscript
2423 (F) The script run under suidperl was somehow illegal.
2425 =item Illegal switch in PERL5OPT: -%c
2427 (X) The PERL5OPT environment variable may only be used to set the
2428 following switches: B<-[CDIMUdmtw]>.
2430 =item Ill-formed CRTL environ value "%s"
2432 (W internal) A warning peculiar to VMS. Perl tried to read the CRTL's
2433 internal environ array, and encountered an element without the C<=>
2434 delimiter used to separate keys from values. The element is ignored.
2436 =item Ill-formed message in prime_env_iter: |%s|
2438 (W internal) A warning peculiar to VMS. Perl tried to read a logical
2439 name or CLI symbol definition when preparing to iterate over %ENV, and
2440 didn't see the expected delimiter between key and value, so the line was
2443 =item (in cleanup) %s
2445 (W misc) This prefix usually indicates that a DESTROY() method raised
2446 the indicated exception. Since destructors are usually called by the
2447 system at arbitrary points during execution, and often a vast number of
2448 times, the warning is issued only once for any number of failures that
2449 would otherwise result in the same message being repeated.
2451 Failure of user callbacks dispatched using the C<G_KEEPERR> flag could
2452 also result in this warning. See L<perlcall/G_KEEPERR>.
2454 =item Incomplete expression within '(?[ ])' in regex; marked by S<<-- HERE>
2457 (F) There was a syntax error within the C<(?[ ])>. This can happen if the
2458 expression inside the construct was completely empty, or if there are
2459 too many or few operands for the number of operators. Perl is not smart
2460 enough to give you a more precise indication as to what is wrong.
2462 =item Inconsistent hierarchy during C3 merge of class '%s': merging failed on
2465 (F) The method resolution order (MRO) of the given class is not
2466 C3-consistent, and you have enabled the C3 MRO for this class. See the C3
2467 documentation in L<mro> for more information.
2469 =item In EBCDIC the v-string components cannot exceed 2147483647
2471 (F) An error peculiar to EBCDIC. Internally, v-strings are stored as
2472 Unicode code points, and encoded in EBCDIC as UTF-EBCDIC. The UTF-EBCDIC
2473 encoding is limited to code points no larger than 2147483647 (0x7FFFFFFF).
2475 =item Infinite recursion in regex
2477 (F) You used a pattern that references itself without consuming any input
2478 text. You should check the pattern to ensure that recursive patterns
2479 either consume text or fail.
2481 =item Initialization of state variables in list context currently forbidden
2483 (F) Currently the implementation of "state" only permits the
2484 initialization of scalar variables in scalar context. Re-write
2485 C<state ($a) = 42> as C<state $a = 42> to change from list to scalar
2486 context. Constructions such as C<state (@a) = foo()> will be
2487 supported in a future perl release.
2489 =item %%s[%s] in scalar context better written as $%s[%s]
2491 (W syntax) In scalar context, you've used an array index/value slice
2492 (indicated by %) to select a single element of an array. Generally
2493 it's better to ask for a scalar value (indicated by $). The difference
2494 is that C<$foo[&bar]> always behaves like a scalar, both in the value it
2495 returns and when evaluating its argument, while C<%foo[&bar]> provides
2496 a list context to its subscript, which can do weird things if you're
2497 expecting only one subscript. When called in list context, it also
2498 returns the index (what C<&bar> returns) in addition to the value.
2500 =item %%s{%s} in scalar context better written as $%s{%s}
2502 (W syntax) In scalar context, you've used a hash key/value slice
2503 (indicated by %) to select a single element of a hash. Generally it's
2504 better to ask for a scalar value (indicated by $). The difference
2505 is that C<$foo{&bar}> always behaves like a scalar, both in the value
2506 it returns and when evaluating its argument, while C<@foo{&bar}> and
2507 provides a list context to its subscript, which can do weird things
2508 if you're expecting only one subscript. When called in list context,
2509 it also returns the key in addition to the value.
2511 =item Insecure dependency in %s
2513 (F) You tried to do something that the tainting mechanism didn't like.
2514 The tainting mechanism is turned on when you're running setuid or
2515 setgid, or when you specify B<-T> to turn it on explicitly. The
2516 tainting mechanism labels all data that's derived directly or indirectly
2517 from the user, who is considered to be unworthy of your trust. If any
2518 such data is used in a "dangerous" operation, you get this error. See
2519 L<perlsec> for more information.
2521 =item Insecure directory in %s
2523 (F) You can't use system(), exec(), or a piped open in a setuid or
2524 setgid script if C<$ENV{PATH}> contains a directory that is writable by
2525 the world. Also, the PATH must not contain any relative directory.
2528 =item Insecure $ENV{%s} while running %s
2530 (F) You can't use system(), exec(), or a piped open in a setuid or
2531 setgid script if any of C<$ENV{PATH}>, C<$ENV{IFS}>, C<$ENV{CDPATH}>,
2532 C<$ENV{ENV}>, C<$ENV{BASH_ENV}> or C<$ENV{TERM}> are derived from data
2533 supplied (or potentially supplied) by the user. The script must set
2534 the path to a known value, using trustworthy data. See L<perlsec>.
2536 =item Insecure user-defined property %s
2538 (F) Perl detected tainted data when trying to compile a regular
2539 expression that contains a call to a user-defined character property
2540 function, i.e. C<\p{IsFoo}> or C<\p{InFoo}>.
2541 See L<perlunicode/User-Defined Character Properties> and L<perlsec>.
2543 =item Integer overflow in format string for %s
2545 (F) The indexes and widths specified in the format string of C<printf()>
2546 or C<sprintf()> are too large. The numbers must not overflow the size of
2547 integers for your architecture.
2549 =item Integer overflow in %s number
2551 (S overflow) The hexadecimal, octal or binary number you have specified
2552 either as a literal or as an argument to hex() or oct() is too big for
2553 your architecture, and has been converted to a floating point number.
2554 On a 32-bit architecture the largest hexadecimal, octal or binary number
2555 representable without overflow is 0xFFFFFFFF, 037777777777, or
2556 0b11111111111111111111111111111111 respectively. Note that Perl
2557 transparently promotes all numbers to a floating point representation
2558 internally--subject to loss of precision errors in subsequent
2561 =item Integer overflow in srand
2563 (S overflow) The number you have passed to srand is too big to fit
2564 in your architecture's integer representation. The number has been
2565 replaced with the largest integer supported (0xFFFFFFFF on 32-bit
2566 architectures). This means you may be getting less randomness than
2567 you expect, because different random seeds above the maximum will
2568 return the same sequence of random numbers.
2570 =item Integer overflow in version
2572 =item Integer overflow in version %d
2574 (W overflow) Some portion of a version initialization is too large for
2575 the size of integers for your architecture. This is not a warning
2576 because there is no rational reason for a version to try and use an
2577 element larger than typically 2**32. This is usually caused by trying
2578 to use some odd mathematical operation as a version, like 100/9.
2580 =item Internal disaster in regex; marked by S<<-- HERE> in m/%s/
2582 (P) Something went badly wrong in the regular expression parser.
2583 The S<<-- HERE> shows whereabouts in the regular expression the problem was
2586 =item Internal inconsistency in tracking vforks
2588 (S) A warning peculiar to VMS. Perl keeps track of the number of times
2589 you've called C<fork> and C<exec>, to determine whether the current call
2590 to C<exec> should affect the current script or a subprocess (see
2591 L<perlvms/"exec LIST">). Somehow, this count has become scrambled, so
2592 Perl is making a guess and treating this C<exec> as a request to
2593 terminate the Perl script and execute the specified command.
2595 =item internal %<num>p might conflict with future printf extensions
2597 (S internal) Perl's internal routine that handles C<printf> and C<sprintf>
2598 formatting follows a slightly different set of rules when called from
2599 C or XS code. Specifically, formats consisting of digits followed
2600 by "p" (e.g., "%7p") are reserved for future use. If you see this
2601 message, then an XS module tried to call that routine with one such
2604 =item Internal urp in regex; marked by S<<-- HERE> in m/%s/
2606 (P) Something went badly awry in the regular expression parser. The
2607 S<<-- HERE> shows whereabouts in the regular expression the problem was
2610 =item %s (...) interpreted as function
2612 (W syntax) You've run afoul of the rule that says that any list operator
2613 followed by parentheses turns into a function, with all the list
2614 operators arguments found inside the parentheses. See
2615 L<perlop/Terms and List Operators (Leftward)>.
2617 =item In '(?...)', the '(' and '?' must be adjacent in regex;
2618 marked by S<<-- HERE> in m/%s/
2620 (F) The two-character sequence C<"(?"> in this context in a regular
2621 expression pattern should be an indivisible token, with nothing
2622 intervening between the C<"("> and the C<"?">, but you separated them
2625 =item Invalid %s attribute: %s
2627 (F) The indicated attribute for a subroutine or variable was not recognized
2628 by Perl or by a user-supplied handler. See L<attributes>.
2630 =item Invalid %s attributes: %s
2632 (F) The indicated attributes for a subroutine or variable were not
2633 recognized by Perl or by a user-supplied handler. See L<attributes>.
2635 =item Invalid character in charnames alias definition; marked by
2638 (F) You tried to create a custom alias for a character name, with
2639 the C<:alias> option to C<use charnames> and the specified character in
2640 the indicated name isn't valid. See L<charnames/CUSTOM ALIASES>.
2642 =item Invalid \0 character in %s for %s: %s\0%s
2644 (W syscalls) Embedded \0 characters in pathnames or other system call
2645 arguments produce a warning as of 5.20. The parts after the \0 were
2646 formerly ignored by system calls.
2648 =item Invalid character in \N{...}; marked by S<<-- HERE> in \N{%s}
2650 (F) Only certain characters are valid for character names. The
2651 indicated one isn't. See L<charnames/CUSTOM ALIASES>.
2653 =item Invalid conversion in %s: "%s"
2655 (W printf) Perl does not understand the given format conversion. See
2656 L<perlfunc/sprintf>.
2658 =item Invalid escape in the specified encoding in regex; marked by
2659 S<<-- HERE> in m/%s/
2661 (W regexp)(F) The numeric escape (for example C<\xHH>) of value < 256
2662 didn't correspond to a single character through the conversion
2663 from the encoding specified by the encoding pragma.
2664 The escape was replaced with REPLACEMENT CHARACTER (U+FFFD)
2665 instead, except within S<C<(?[ ])>>, where it is a fatal error.
2666 The S<<-- HERE> shows whereabouts in the regular expression the
2667 escape was discovered.
2669 =item Invalid hexadecimal number in \N{U+...}
2671 =item Invalid hexadecimal number in \N{U+...} in regex; marked by
2672 S<<-- HERE> in m/%s/
2674 (F) The character constant represented by C<...> is not a valid hexadecimal
2675 number. Either it is empty, or you tried to use a character other than
2676 0 - 9 or A - F, a - f in a hexadecimal number.
2678 =item Invalid module name %s with -%c option: contains single ':'
2680 (F) The module argument to perl's B<-m> and B<-M> command-line options
2681 cannot contain single colons in the module name, but only in the
2682 arguments after "=". In other words, B<-MFoo::Bar=:baz> is ok, but
2683 B<-MFoo:Bar=baz> is not.
2685 =item Invalid mro name: '%s'
2687 (F) You tried to C<mro::set_mro("classname", "foo")> or C<use mro 'foo'>,
2688 where C<foo> is not a valid method resolution order (MRO). Currently,
2689 the only valid ones supported are C<dfs> and C<c3>, unless you have loaded
2690 a module that is a MRO plugin. See L<mro> and L<perlmroapi>.
2692 =item Invalid negative number (%s) in chr
2694 (W utf8) You passed a negative number to C<chr>. Negative numbers are
2695 not valid character numbers, so it returns the Unicode replacement
2698 =item invalid option -D%c, use -D'' to see choices
2700 (S debugging) Perl was called with invalid debugger flags. Call perl
2701 with the B<-D> option with no flags to see the list of acceptable values.
2702 See also L<perlrun/-Dletters>.
2704 =item Invalid [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
2706 (F) The range specified in a character class had a minimum character
2707 greater than the maximum character. One possibility is that you forgot the
2708 C<{}> from your ending C<\x{}> - C<\x> without the curly braces can go only
2709 up to C<ff>. The S<<-- HERE> shows whereabouts in the regular expression the
2710 problem was discovered. See L<perlre>.
2712 =item Invalid range "%s" in transliteration operator
2714 (F) The range specified in the tr/// or y/// operator had a minimum
2715 character greater than the maximum character. See L<perlop>.
2717 =item Invalid separator character %s in attribute list
2719 (F) Something other than a colon or whitespace was seen between the
2720 elements of an attribute list. If the previous attribute had a
2721 parenthesised parameter list, perhaps that list was terminated too soon.
2724 =item Invalid separator character %s in PerlIO layer specification %s
2726 (W layer) When pushing layers onto the Perl I/O system, something other
2727 than a colon or whitespace was seen between the elements of a layer list.
2728 If the previous attribute had a parenthesised parameter list, perhaps that
2729 list was terminated too soon.
2731 =item Invalid strict version format (%s)
2733 (F) A version number did not meet the "strict" criteria for versions.
2734 A "strict" version number is a positive decimal number (integer or
2735 decimal-fraction) without exponentiation or else a dotted-decimal
2736 v-string with a leading 'v' character and at least three components.
2737 The parenthesized text indicates which criteria were not met.
2738 See the L<version> module for more details on allowed version formats.
2740 =item Invalid type '%s' in %s
2742 (F) The given character is not a valid pack or unpack type.
2743 See L<perlfunc/pack>.
2745 (W) The given character is not a valid pack or unpack type but used to be
2748 =item Invalid version format (%s)
2750 (F) A version number did not meet the "lax" criteria for versions.
2751 A "lax" version number is a positive decimal number (integer or
2752 decimal-fraction) without exponentiation or else a dotted-decimal
2753 v-string. If the v-string has fewer than three components, it
2754 must have a leading 'v' character. Otherwise, the leading 'v' is
2755 optional. Both decimal and dotted-decimal versions may have a
2756 trailing "alpha" component separated by an underscore character
2757 after a fractional or dotted-decimal component. The parenthesized
2758 text indicates which criteria were not met. See the L<version> module
2759 for more details on allowed version formats.
2761 =item Invalid version object
2763 (F) The internal structure of the version object was invalid.
2764 Perhaps the internals were modified directly in some way or
2765 an arbitrary reference was blessed into the "version" class.
2767 =item In '(*VERB...)', the '(' and '*' must be adjacent in regex;
2768 marked by S<<-- HERE> in m/%s/
2770 (F) The two-character sequence C<"(*"> in
2771 this context in a regular expression pattern should be an
2772 indivisible token, with nothing intervening between the C<"(">
2773 and the C<"*">, but you separated them.
2775 =item ioctl is not implemented
2777 (F) Your machine apparently doesn't implement ioctl(), which is pretty
2778 strange for a machine that supports C.
2780 =item ioctl() on unopened %s
2782 (W unopened) You tried ioctl() on a filehandle that was never opened.
2783 Check your control flow and number of arguments.
2785 =item IO layers (like '%s') unavailable
2787 (F) Your Perl has not been configured to have PerlIO, and therefore
2788 you cannot use IO layers. To have PerlIO, Perl must be configured
2791 =item IO::Socket::atmark not implemented on this architecture
2793 (F) Your machine doesn't implement the sockatmark() functionality,
2794 neither as a system call nor an ioctl call (SIOCATMARK).
2796 =item $* is no longer supported
2798 (D deprecated, syntax) The special variable C<$*>, deprecated in older
2799 perls, has been removed as of 5.10.0 and is no longer supported. In
2800 previous versions of perl the use of C<$*> enabled or disabled multi-line
2801 matching within a string.
2803 Instead of using C<$*> you should use the C</m> (and maybe C</s>) regexp
2804 modifiers. You can enable C</m> for a lexical scope (even a whole file)
2805 with C<use re '/m'>. (In older versions: when C<$*> was set to a true value
2806 then all regular expressions behaved as if they were written using C</m>.)
2808 =item $# is no longer supported
2810 (D deprecated, syntax) The special variable C<$#>, deprecated in older
2811 perls, has been removed as of 5.10.0 and is no longer supported. You
2812 should use the printf/sprintf functions instead.
2814 =item '%s' is not a code reference
2816 (W overload) The second (fourth, sixth, ...) argument of
2817 overload::constant needs to be a code reference. Either
2818 an anonymous subroutine, or a reference to a subroutine.
2820 =item '%s' is not an overloadable type
2822 (W overload) You tried to overload a constant type the overload package is
2825 =item -i used with no filenames on the command line, reading from STDIN
2827 (S inplace) The C<-i> option was passed on the command line, indicating
2828 that the script is intended to edit files in place, but no files were
2829 given. This is usually a mistake, since editing STDIN in place doesn't
2830 make sense, and can be confusing because it can make perl look like
2831 it is hanging when it is really just trying to read from STDIN. You
2832 should either pass a filename to edit, or remove C<-i> from the command
2833 line. See L<perlrun> for more details.
2835 =item Junk on end of regexp in regex m/%s/
2837 (P) The regular expression parser is confused.
2839 =item keys on reference is experimental
2841 (S experimental::autoderef) C<keys> with a scalar argument is experimental
2842 and may change or be removed in a future Perl version. If you want to
2843 take the risk of using this feature, simply disable this warning:
2845 no warnings "experimental::autoderef";
2847 =item Label not found for "last %s"
2849 (F) You named a loop to break out of, but you're not currently in a loop
2850 of that name, not even if you count where you were called from. See
2853 =item Label not found for "next %s"
2855 (F) You named a loop to continue, but you're not currently in a loop of
2856 that name, not even if you count where you were called from. See
2859 =item Label not found for "redo %s"
2861 (F) You named a loop to restart, but you're not currently in a loop of
2862 that name, not even if you count where you were called from. See
2865 =item leaving effective %s failed
2867 (F) While under the C<use filetest> pragma, switching the real and
2868 effective uids or gids failed.
2870 =item length/code after end of string in unpack
2872 (F) While unpacking, the string buffer was already used up when an unpack
2873 length/code combination tried to obtain more data. This results in
2874 an undefined value for the length. See L<perlfunc/pack>.
2876 =item length() used on %s (did you mean "scalar(%s)"?)
2878 (W syntax) You used length() on either an array or a hash when you
2879 probably wanted a count of the items.
2881 Array size can be obtained by doing:
2885 The number of items in a hash can be obtained by doing:
2889 =item Lexing code attempted to stuff non-Latin-1 character into Latin-1 input
2891 (F) An extension is attempting to insert text into the current parse
2892 (using L<lex_stuff_pvn|perlapi/lex_stuff_pvn> or similar), but tried to insert a character that
2893 couldn't be part of the current input. This is an inherent pitfall
2894 of the stuffing mechanism, and one of the reasons to avoid it. Where
2895 it is necessary to stuff, stuffing only plain ASCII is recommended.
2897 =item Lexing code internal error (%s)
2899 (F) Lexing code supplied by an extension violated the lexer's API in a
2902 =item listen() on closed socket %s
2904 (W closed) You tried to do a listen on a closed socket. Did you forget
2905 to check the return value of your socket() call? See
2908 =item List form of piped open not implemented
2910 (F) On some platforms, notably Windows, the three-or-more-arguments
2911 form of C<open> does not support pipes, such as C<open($pipe, '|-', @args)>.
2912 Use the two-argument C<open($pipe, '|prog arg1 arg2...')> form instead.
2914 =item localtime(%f) failed
2916 (W overflow) You called C<localtime> with a number that it could not handle:
2917 too large, too small, or NaN. The returned value is C<undef>.
2919 =item localtime(%f) too large
2921 (W overflow) You called C<localtime> with a number that was larger
2922 than it can reliably handle and C<localtime> probably returned the
2923 wrong date. This warning is also triggered with NaN (the special
2924 not-a-number value).
2926 =item localtime(%f) too small
2928 (W overflow) You called C<localtime> with a number that was smaller
2929 than it can reliably handle and C<localtime> probably returned the
2932 =item Lookbehind longer than %d not implemented in regex m/%s/
2934 (F) There is currently a limit on the length of string which lookbehind can
2935 handle. This restriction may be eased in a future release.
2937 =item Lost precision when %s %f by 1
2939 (W imprecision) The value you attempted to increment or decrement by one
2940 is too large for the underlying floating point representation to store
2941 accurately, hence the target of C<++> or C<--> is unchanged. Perl issues this
2942 warning because it has already switched from integers to floating point
2943 when values are too large for integers, and now even floating point is
2944 insufficient. You may wish to switch to using L<Math::BigInt> explicitly.
2946 =item lstat() on filehandle%s
2948 (W io) You tried to do an lstat on a filehandle. What did you mean
2949 by that? lstat() makes sense only on filenames. (Perl did a fstat()
2950 instead on the filehandle.)
2952 =item lvalue attribute %s already-defined subroutine
2954 (W misc) Although L<attributes.pm|attributes> allows this, turning the lvalue
2955 attribute on or off on a Perl subroutine that is already defined
2956 does not always work properly. It may or may not do what you
2957 want, depending on what code is inside the subroutine, with exact
2958 details subject to change between Perl versions. Only do this
2959 if you really know what you are doing.
2961 =item lvalue attribute ignored after the subroutine has been defined
2963 (W misc) Using the C<:lvalue> declarative syntax to make a Perl
2964 subroutine an lvalue subroutine after it has been defined is
2965 not permitted. To make the subroutine an lvalue subroutine,
2966 add the lvalue attribute to the definition, or put the C<sub
2967 foo :lvalue;> declaration before the definition.
2969 See also L<attributes.pm|attributes>.
2971 =item Magical list constants are not supported
2973 (F) You assigned a magical array to a stash element, and then tried
2974 to use the subroutine from the same slot. You are asking Perl to do
2975 something it cannot do, details subject to change between Perl versions.
2977 =item Malformed integer in [] in pack
2979 (F) Between the brackets enclosing a numeric repeat count only digits
2980 are permitted. See L<perlfunc/pack>.
2982 =item Malformed integer in [] in unpack
2984 (F) Between the brackets enclosing a numeric repeat count only digits
2985 are permitted. See L<perlfunc/pack>.
2987 =item Malformed PERLLIB_PREFIX
2989 (F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form
2996 with nonempty prefix1 and prefix2. If C<prefix1> is indeed a prefix of
2997 a builtin library search path, prefix2 is substituted. The error may
2998 appear if components are not found, or are too long. See
2999 "PERLLIB_PREFIX" in L<perlos2>.
3001 =item Malformed prototype for %s: %s
3003 (F) You tried to use a function with a malformed prototype. The
3004 syntax of function prototypes is given a brief compile-time check for
3005 obvious errors like invalid characters. A more rigorous check is run
3006 when the function is called.
3007 Perhaps the function's author was trying to write a subroutine signature
3008 but didn't enable that feature first (C<use feature 'signatures'>),
3009 so the signature was instead interpreted as a bad prototype.
3011 =item Malformed UTF-8 character (%s)
3013 (S utf8)(F) Perl detected a string that didn't comply with UTF-8
3014 encoding rules, even though it had the UTF8 flag on.
3016 One possible cause is that you set the UTF8 flag yourself for data that
3017 you thought to be in UTF-8 but it wasn't (it was for example legacy
3018 8-bit data). To guard against this, you can use Encode::decode_utf8.
3020 If you use the C<:encoding(UTF-8)> PerlIO layer for input, invalid byte
3021 sequences are handled gracefully, but if you use C<:utf8>, the flag is
3022 set without validating the data, possibly resulting in this error
3025 See also L<Encode/"Handling Malformed Data">.
3027 =item Malformed UTF-8 character immediately after '%s'
3029 (F) You said C<use utf8>, but the program file doesn't comply with UTF-8
3030 encoding rules. The message prints out the properly encoded characters
3031 just before the first bad one. If C<utf8> warnings are enabled, a
3032 warning is generated that gives more details about the type of
3035 =item Malformed UTF-8 returned by \N{%s} immediately after '%s'
3037 (F) The charnames handler returned malformed UTF-8.
3039 =item Malformed UTF-8 string in '%c' format in unpack
3041 (F) You tried to unpack something that didn't comply with UTF-8 encoding
3042 rules and perl was unable to guess how to make more progress.
3044 =item Malformed UTF-8 string in pack
3046 (F) You tried to pack something that didn't comply with UTF-8 encoding
3047 rules and perl was unable to guess how to make more progress.
3049 =item Malformed UTF-8 string in unpack
3051 (F) You tried to unpack something that didn't comply with UTF-8 encoding
3052 rules and perl was unable to guess how to make more progress.
3054 =item Malformed UTF-16 surrogate
3056 (F) Perl thought it was reading UTF-16 encoded character data but while
3057 doing it Perl met a malformed Unicode surrogate.
3059 =item Mandatory parameter follows optional parameter
3061 (F) In a subroutine signature, you wrote something like "$a = undef,
3062 $b", making an earlier parameter optional and a later one mandatory.
3063 Parameters are filled from left to right, so it's impossible for the
3064 caller to omit an earlier one and pass a later one. If you want to act
3065 as if the parameters are filled from right to left, declare the rightmost
3066 optional and then shuffle the parameters around in the subroutine's body.
3068 =item Matched non-Unicode code point 0x%X against Unicode property; may
3071 (S non_unicode) Perl allows strings to contain a superset of
3072 Unicode code points; each code point may be as large as what is storable
3073 in an unsigned integer on your system, but these may not be accepted by
3074 other languages/systems. This message occurs when you matched a string
3075 containing such a code point against a regular expression pattern, and
3076 the code point was matched against a Unicode property, C<\p{...}> or
3077 C<\P{...}>. Unicode properties are only defined on Unicode code points,
3078 so the result of this match is undefined by Unicode, but Perl (starting
3079 in v5.20) treats non-Unicode code points as if they were typical
3080 unassigned Unicode ones, and matched this one accordingly. Whether a
3081 given property matches these code points or not is specified in
3082 L<perluniprops/Properties accessible through \p{} and \P{}>.
3084 This message is suppressed (unless it has been made fatal) if it is
3085 immaterial to the results of the match if the code point is Unicode or
3086 not. For example, the property C<\p{ASCII_Hex_Digit}> only can match
3087 the 22 characters C<[0-9A-Fa-f]>, so obviously all other code points,
3088 Unicode or not, won't match it. (And C<\P{ASCII_Hex_Digit}> will match
3089 every code point except these 22.)
3091 Getting this message indicates that the outcome of the match arguably
3092 should have been the opposite of what actually happened. If you think
3093 that is the case, you may wish to make the C<non_unicode> warnings
3094 category fatal; if you agree with Perl's decision, you may wish to turn
3097 See L<perlunicode/Beyond Unicode code points> for more information.
3099 =item %s matches null string many times in regex; marked by S<<-- HERE> in
3102 (W regexp) The pattern you've specified would be an infinite loop if the
3103 regular expression engine didn't specifically check for that. The S<<-- HERE>
3104 shows whereabouts in the regular expression the problem was discovered.
3107 =item Maximal count of pending signals (%u) exceeded
3109 (F) Perl aborted due to too high a number of signals pending. This
3110 usually indicates that your operating system tried to deliver signals
3111 too fast (with a very high priority), starving the perl process from
3112 resources it would need to reach a point where it can process signals
3113 safely. (See L<perlipc/"Deferred Signals (Safe Signals)">.)
3115 =item "%s" may clash with future reserved word
3117 (W) This warning may be due to running a perl5 script through a perl4
3118 interpreter, especially if the word that is being warned about is
3121 =item '%' may not be used in pack
3123 (F) You can't pack a string by supplying a checksum, because the
3124 checksumming process loses information, and you can't go the other way.
3125 See L<perlfunc/unpack>.
3127 =item Method for operation %s not found in package %s during blessing
3129 (F) An attempt was made to specify an entry in an overloading table that
3130 doesn't resolve to a valid subroutine. See L<overload>.
3132 =item Method %s not permitted
3136 =item Might be a runaway multi-line %s string starting on line %d
3138 (S) An advisory indicating that the previous error may have been caused
3139 by a missing delimiter on a string or pattern, because it eventually
3140 ended earlier on the current line.
3142 =item Misplaced _ in number
3144 (W syntax) An underscore (underbar) in a numeric constant did not
3145 separate two digits.
3147 =item Missing argument in %s
3149 (W missing) You called a function with fewer arguments than other
3150 arguments you supplied indicated would be needed.
3152 Currently only emitted when a printf-type format required more
3153 arguments than were supplied, but might be used in the future for
3154 other cases where we can statically determine that arguments to
3155 functions are missing, e.g. for the L<perlfunc/pack> function.
3157 =item Missing argument to -%c
3159 (F) The argument to the indicated command line switch must follow
3160 immediately after the switch, without intervening spaces.
3162 =item Missing braces on \N{}
3164 =item Missing braces on \N{} in regex; marked by S<<-- HERE> in m/%s/
3166 (F) Wrong syntax of character name literal C<\N{charname}> within
3167 double-quotish context. This can also happen when there is a space
3168 (or comment) between the C<\N> and the C<{> in a regex with the C</x> modifier.
3169 This modifier does not change the requirement that the brace immediately
3172 =item Missing braces on \o{}
3174 (F) A C<\o> must be followed immediately by a C<{> in double-quotish context.
3176 =item Missing comma after first argument to %s function
3178 (F) While certain functions allow you to specify a filehandle or an
3179 "indirect object" before the argument list, this ain't one of them.
3181 =item Missing command in piped open
3183 (W pipe) You used the C<open(FH, "| command")> or
3184 C<open(FH, "command |")> construction, but the command was missing or
3187 =item Missing control char name in \c
3189 (F) A double-quoted string ended with "\c", without the required control
3192 =item Missing ']' in prototype for %s : %s
3194 (W illegalproto) A grouping was started with C<[> but never closed with C<]>.
3196 =item Missing name in "%s sub"
3198 (F) The syntax for lexically scoped subroutines requires that
3199 they have a name with which they can be found.
3201 =item Missing $ on loop variable
3203 (F) Apparently you've been programming in B<csh> too much. Variables
3204 are always mentioned with the $ in Perl, unlike in the shells, where it
3205 can vary from one line to the next.
3207 =item (Missing operator before %s?)
3209 (S syntax) This is an educated guess made in conjunction with the message
3210 "%s found where operator expected". Often the missing operator is a comma.
3212 =item Missing or undefined argument to require
3214 (F) You tried to call require with no argument or with an undefined
3215 value as an argument. Require expects either a package name or a
3216 file-specification as an argument. See L<perlfunc/require>.
3218 =item Missing right brace on \%c{} in regex; marked by S<<-- HERE> in m/%s/
3220 (F) Missing right brace in C<\x{...}>, C<\p{...}>, C<\P{...}>, or C<\N{...}>.
3222 =item Missing right brace on \N{} or unescaped left brace after \N
3224 (F) C<\N> has two meanings.
3226 The traditional one has it followed by a name enclosed in braces,
3227 meaning the character (or sequence of characters) given by that
3228 name. Thus C<\N{ASTERISK}> is another way of writing C<*>, valid in both
3229 double-quoted strings and regular expression patterns. In patterns,
3230 it doesn't have the meaning an unescaped C<*> does.
3232 Starting in Perl 5.12.0, C<\N> also can have an additional meaning (only)
3233 in patterns, namely to match a non-newline character. (This is short
3234 for C<[^\n]>, and like C<.> but is not affected by the C</s> regex modifier.)
3236 This can lead to some ambiguities. When C<\N> is not followed immediately
3237 by a left brace, Perl assumes the C<[^\n]> meaning. Also, if the braces
3238 form a valid quantifier such as C<\N{3}> or C<\N{5,}>, Perl assumes that this
3239 means to match the given quantity of non-newlines (in these examples,
3240 3; and 5 or more, respectively). In all other case, where there is a
3241 C<\N{> and a matching C<}>, Perl assumes that a character name is desired.
3243 However, if there is no matching C<}>, Perl doesn't know if it was
3244 mistakenly omitted, or if C<[^\n]{> was desired, and raises this error.
3245 If you meant the former, add the right brace; if you meant the latter,
3246 escape the brace with a backslash, like so: C<\N\{>
3248 =item Missing right curly or square bracket
3250 (F) The lexer counted more opening curly or square brackets than closing
3251 ones. As a general rule, you'll find it's missing near the place you
3254 =item (Missing semicolon on previous line?)
3256 (S syntax) This is an educated guess made in conjunction with the message
3257 "%s found where operator expected". Don't automatically put a semicolon on
3258 the previous line just because you saw this message.
3260 =item Modification of a read-only value attempted
3262 (F) You tried, directly or indirectly, to change the value of a
3263 constant. You didn't, of course, try "2 = 1", because the compiler
3264 catches that. But an easy way to do the same thing is:
3266 sub mod { $_[0] = 1 }
3269 Another way is to assign to a substr() that's off the end of the string.
3271 Yet another way is to assign to a C<foreach> loop I<VAR> when I<VAR>
3272 is aliased to a constant in the look I<LIST>:
3275 foreach my $n ($x, 2) {
3276 $n *= 2; # modifies the $x, but fails on attempt to
3279 =item Modification of non-creatable array value attempted, %s
3281 (F) You tried to make an array value spring into existence, and the
3282 subscript was probably negative, even counting from end of the array
3285 =item Modification of non-creatable hash value attempted, %s
3287 (P) You tried to make a hash value spring into existence, and it
3288 couldn't be created for some peculiar reason.
3290 =item Module name must be constant
3292 (F) Only a bare module name is allowed as the first argument to a "use".
3294 =item Module name required with -%c option
3296 (F) The C<-M> or C<-m> options say that Perl should load some module, but
3297 you omitted the name of the module. Consult L<perlrun> for full details
3298 about C<-M> and C<-m>.
3300 =item More than one argument to '%s' open
3302 (F) The C<open> function has been asked to open multiple files. This
3303 can happen if you are trying to open a pipe to a command that takes a
3304 list of arguments, but have forgotten to specify a piped open mode.
3305 See L<perlfunc/open> for details.
3307 =item mprotect for COW string %p %u failed with %d
3309 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_COW (see
3310 L<perlguts/"Copy on Write">), but a shared string buffer
3311 could not be made read-only.
3313 =item mprotect for %p %u failed with %d
3315 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_OPS (see L<perlhacktips>),
3316 but an op tree could not be made read-only.
3318 =item mprotect RW for COW string %p %u failed with %d
3320 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_COW (see
3321 L<perlguts/"Copy on Write">), but a read-only shared string
3322 buffer could not be made mutable.
3324 =item mprotect RW for %p %u failed with %d
3326 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_OPS (see
3327 L<perlhacktips>), but a read-only op tree could not be made
3328 mutable before freeing the ops.
3330 =item msg%s not implemented
3332 (F) You don't have System V message IPC on your system.
3334 =item Multidimensional syntax %s not supported
3336 (W syntax) Multidimensional arrays aren't written like C<$foo[1,2,3]>.
3337 They're written like C<$foo[1][2][3]>, as in C.
3339 =item '/' must follow a numeric type in unpack
3341 (F) You had an unpack template that contained a '/', but this did not
3342 follow some unpack specification producing a numeric value.
3343 See L<perlfunc/pack>.
3345 =item "my sub" not yet implemented
3347 (F) Lexically scoped subroutines are not yet implemented. Don't try
3350 =item "my" subroutine %s can't be in a package
3352 (F) Lexically scoped subroutines aren't in a package, so it doesn't make
3353 sense to try to declare one with a package qualifier on the front.
3355 =item "my %s" used in sort comparison
3357 (W syntax) The package variables $a and $b are used for sort comparisons.
3358 You used $a or $b in as an operand to the C<< <=> >> or C<cmp> operator inside a
3359 sort comparison block, and the variable had earlier been declared as a
3360 lexical variable. Either qualify the sort variable with the package
3361 name, or rename the lexical variable.
3363 =item "my" variable %s can't be in a package
3365 (F) Lexically scoped variables aren't in a package, so it doesn't make
3366 sense to try to declare one with a package qualifier on the front. Use
3367 local() if you want to localize a package variable.
3369 =item Name "%s::%s" used only once: possible typo
3371 (W once) Typographical errors often show up as unique variable
3372 names. If you had a good reason for having a unique name, then
3373 just mention it again somehow to suppress the message. The C<our>
3374 declaration is also provided for this purpose.
3376 NOTE: This warning detects package symbols that have been used
3377 only once. This means lexical variables will never trigger this
3378 warning. It also means that all of the package variables $c, @c,
3379 %c, as well as *c, &c, sub c{}, c(), and c (the filehandle or
3380 format) are considered the same; if a program uses $c only once
3381 but also uses any of the others it will not trigger this warning.
3382 Symbols beginning with an underscore and symbols using special
3383 identifiers (q.v. L<perldata>) are exempt from this warning.
3385 =item Need exactly 3 octal digits in regex; marked by S<<-- HERE> in m/%s/
3387 (F) Within S<C<(?[ ])>>, all constants interpreted as octal need to be
3388 exactly 3 digits long. This helps catch some ambiguities. If your
3389 constant is too short, add leading zeros, like
3391 (?[ [ \078 ] ]) # Syntax error!
3392 (?[ [ \0078 ] ]) # Works
3393 (?[ [ \007 8 ] ]) # Clearer
3395 The maximum number this construct can express is C<\777>. If you
3396 need a larger one, you need to use L<\o{}|perlrebackslash/Octal escapes> instead. If you meant
3397 two separate things, you need to separate them:
3399 (?[ [ \7776 ] ]) # Syntax error!
3400 (?[ [ \o{7776} ] ]) # One meaning
3401 (?[ [ \777 6 ] ]) # Another meaning
3402 (?[ [ \777 \006 ] ]) # Still another
3404 =item Negative '/' count in unpack
3406 (F) The length count obtained from a length/code unpack operation was
3407 negative. See L<perlfunc/pack>.
3409 =item Negative length
3411 (F) You tried to do a read/write/send/recv operation with a buffer
3412 length that is less than 0. This is difficult to imagine.
3414 =item Negative offset to vec in lvalue context
3416 (F) When C<vec> is called in an lvalue context, the second argument must be
3417 greater than or equal to zero.
3419 =item Negative repeat count does nothing
3421 (W numeric) You tried to execute the
3422 L<C<x>|perlop/Multiplicative Operators> repetition operator fewer than 0
3423 times, which doesn't make sense.
3425 =item Nested quantifiers in regex; marked by S<<-- HERE> in m/%s/
3427 (F) You can't quantify a quantifier without intervening parentheses.
3428 So things like ** or +* or ?* are illegal. The S<<-- HERE> shows
3429 whereabouts in the regular expression the problem was discovered.
3431 Note that the minimal matching quantifiers, C<*?>, C<+?>, and
3432 C<??> appear to be nested quantifiers, but aren't. See L<perlre>.
3434 =item %s never introduced
3436 (S internal) The symbol in question was declared but somehow went out of
3437 scope before it could possibly have been used.
3439 =item next::method/next::can/maybe::next::method cannot find enclosing method
3441 (F) C<next::method> needs to be called within the context of a
3442 real method in a real package, and it could not find such a context.
3445 =item \N in a character class must be a named character: \N{...} in regex;
3446 marked by S<<-- HERE> in m/%s/
3448 (F) The new (as of Perl 5.12) meaning of C<\N> as C<[^\n]> is not valid in a
3449 bracketed character class, for the same reason that C<.> in a character
3450 class loses its specialness: it matches almost everything, which is
3451 probably not what you want.
3453 =item \N{} in inverted character class or as a range end-point is restricted to one character in regex; marked
3454 by S<<-- HERE> in m/%s/
3456 (F) Named Unicode character escapes (C<\N{...}>) may return a
3457 multi-character sequence. Even though a character class is
3458 supposed to match just one character of input, perl will match the
3459 whole thing correctly, except when the class is inverted (C<[^...]>),
3460 or the escape is the beginning or final end point of a range. The
3461 mathematically logical behavior for what matches when inverting
3462 is very different from what people expect, so we have decided to
3463 forbid it. Similarly unclear is what should be generated when the
3464 C<\N{...}> is used as one of the end points of the range, such as in
3466 [\x{41}-\N{ARABIC SEQUENCE YEH WITH HAMZA ABOVE WITH AE}]
3468 What is meant here is unclear, as the C<\N{...}> escape is a sequence
3469 of code points, so this is made an error.
3471 =item \N{NAME} must be resolved by the lexer in regex; marked by
3472 S<<-- HERE> in m/%s/
3474 (F) When compiling a regex pattern, an unresolved named character or
3475 sequence was encountered. This can happen in any of several ways that
3476 bypass the lexer, such as using single-quotish context, or an extra
3477 backslash in double-quotish:
3479 $re = '\N{SPACE}'; # Wrong!
3480 $re = "\\N{SPACE}"; # Wrong!
3483 Instead, use double-quotes with a single backslash:
3485 $re = "\N{SPACE}"; # ok
3488 The lexer can be bypassed as well by creating the pattern from smaller
3492 /${re}{SPACE}/; # Wrong!
3494 It's not a good idea to split a construct in the middle like this, and
3495 it doesn't work here. Instead use the solution above.
3497 Finally, the message also can happen under the C</x> regex modifier when the
3498 C<\N> is separated by spaces from the C<{>, in which case, remove the spaces.
3500 /\N {SPACE}/x; # Wrong!
3503 =item No %s allowed while running setuid
3505 (F) Certain operations are deemed to be too insecure for a setuid or
3506 setgid script to even be allowed to attempt. Generally speaking there
3507 will be another way to do what you want that is, if not secure, at least
3508 securable. See L<perlsec>.
3510 =item NO-BREAK SPACE in a charnames alias definition is deprecated
3512 (D deprecated) You defined a character name which contained a no-break
3513 space character. Change it to a regular space. Usually these names are
3514 defined in the C<:alias> import argument to C<use charnames>, but they
3515 could be defined by a translator installed into C<$^H{charnames}>. See
3516 L<charnames/CUSTOM ALIASES>.
3518 =item No code specified for -%c
3520 (F) Perl's B<-e> and B<-E> command-line options require an argument. If
3521 you want to run an empty program, pass the empty string as a separate
3522 argument or run a program consisting of a single 0 or 1:
3528 =item No comma allowed after %s
3530 (F) A list operator that has a filehandle or "indirect object" is
3531 not allowed to have a comma between that and the following arguments.
3532 Otherwise it'd be just another one of the arguments.
3534 One possible cause for this is that you expected to have imported
3535 a constant to your name space with B<use> or B<import> while no such
3536 importing took place, it may for example be that your operating
3537 system does not support that particular constant. Hopefully you did
3538 use an explicit import list for the constants you expect to see;
3539 please see L<perlfunc/use> and L<perlfunc/import>. While an
3540 explicit import list would probably have caught this error earlier
3541 it naturally does not remedy the fact that your operating system
3542 still does not support that constant. Maybe you have a typo in
3543 the constants of the symbol import list of B<use> or B<import> or in the
3544 constant name at the line where this error was triggered?
3546 =item No command into which to pipe on command line
3548 (F) An error peculiar to VMS. Perl handles its own command line
3549 redirection, and found a '|' at the end of the command line, so it
3550 doesn't know where you want to pipe the output from this command.
3552 =item No DB::DB routine defined
3554 (F) The currently executing code was compiled with the B<-d> switch, but
3555 for some reason the current debugger (e.g. F<perl5db.pl> or a C<Devel::>
3556 module) didn't define a routine to be called at the beginning of each
3559 =item No dbm on this machine
3561 (P) This is counted as an internal error, because every machine should
3562 supply dbm nowadays, because Perl comes with SDBM. See L<SDBM_File>.
3564 =item No DB::sub routine defined
3566 (F) The currently executing code was compiled with the B<-d> switch, but
3567 for some reason the current debugger (e.g. F<perl5db.pl> or a C<Devel::>
3568 module) didn't define a C<DB::sub> routine to be called at the beginning
3569 of each ordinary subroutine call.
3571 =item No directory specified for -I
3573 (F) The B<-I> command-line switch requires a directory name as part of the
3574 I<same> argument. Use B<-Ilib>, for instance. B<-I lib> won't work.
3576 =item No error file after 2> or 2>> on command line
3578 (F) An error peculiar to VMS. Perl handles its own command line
3579 redirection, and found a '2>' or a '2>>' on the command line, but can't
3580 find the name of the file to which to write data destined for stderr.
3582 =item No group ending character '%c' found in template
3584 (F) A pack or unpack template has an opening '(' or '[' without its
3585 matching counterpart. See L<perlfunc/pack>.
3587 =item No input file after < on command line
3589 (F) An error peculiar to VMS. Perl handles its own command line
3590 redirection, and found a '<' on the command line, but can't find the
3591 name of the file from which to read data for stdin.
3593 =item No next::method '%s' found for %s
3595 (F) C<next::method> found no further instances of this method name
3596 in the remaining packages of the MRO of this class. If you don't want
3597 it throwing an exception, use C<maybe::next::method>
3598 or C<next::can>. See L<mro>.
3600 =item Non-hex character in regex; marked by S<<-- HERE> in m/%s/
3602 (F) In a regular expression, there was a non-hexadecimal character where
3603 a hex one was expected, like
3608 =item Non-octal character in regex; marked by S<<-- HERE> in m/%s/
3610 (F) In a regular expression, there was a non-octal character where
3611 an octal one was expected, like
3615 =item Non-octal character '%c'. Resolved as "%s"
3617 (W digit) In parsing an octal numeric constant, a character was
3618 unexpectedly encountered that isn't octal. The resulting value
3621 =item "no" not allowed in expression
3623 (F) The "no" keyword is recognized and executed at compile time, and
3624 returns no useful value. See L<perlmod>.
3626 =item Non-string passed as bitmask
3628 (W misc) A number has been passed as a bitmask argument to select().
3629 Use the vec() function to construct the file descriptor bitmasks for
3630 select. See L<perlfunc/select>.
3632 =item No output file after > on command line
3634 (F) An error peculiar to VMS. Perl handles its own command line
3635 redirection, and found a lone '>' at the end of the command line, so it
3636 doesn't know where you wanted to redirect stdout.
3638 =item No output file after > or >> on command line
3640 (F) An error peculiar to VMS. Perl handles its own command line
3641 redirection, and found a '>' or a '>>' on the command line, but can't
3642 find the name of the file to which to write data destined for stdout.
3644 =item No package name allowed for variable %s in "our"
3646 (F) Fully qualified variable names are not allowed in "our"
3647 declarations, because that doesn't make much sense under existing
3648 semantics. Such syntax is reserved for future extensions.
3650 =item No Perl script found in input
3652 (F) You called C<perl -x>, but no line was found in the file beginning
3653 with #! and containing the word "perl".
3655 =item No setregid available
3657 (F) Configure didn't find anything resembling the setregid() call for
3660 =item No setreuid available
3662 (F) Configure didn't find anything resembling the setreuid() call for
3665 =item No such class %s
3667 (F) You provided a class qualifier in a "my", "our" or "state"
3668 declaration, but this class doesn't exist at this point in your program.
3670 =item No such class field "%s" in variable %s of type %s
3672 (F) You tried to access a key from a hash through the indicated typed
3673 variable but that key is not allowed by the package of the same type.
3674 The indicated package has restricted the set of allowed keys using the
3677 =item No such hook: %s
3679 (F) You specified a signal hook that was not recognized by Perl.
3680 Currently, Perl accepts C<__DIE__> and C<__WARN__> as valid signal hooks.
3682 =item No such pipe open
3684 (P) An error peculiar to VMS. The internal routine my_pclose() tried to
3685 close a pipe which hadn't been opened. This should have been caught
3686 earlier as an attempt to close an unopened filehandle.
3688 =item No such signal: SIG%s
3690 (W signal) You specified a signal name as a subscript to %SIG that was
3691 not recognized. Say C<kill -l> in your shell to see the valid signal
3692 names on your system.
3694 =item Not a CODE reference
3696 (F) Perl was trying to evaluate a reference to a code value (that is, a
3697 subroutine), but found a reference to something else instead. You can
3698 use the ref() function to find out what kind of ref it really was. See
3701 =item Not a GLOB reference
3703 (F) Perl was trying to evaluate a reference to a "typeglob" (that is, a
3704 symbol table entry that looks like C<*foo>), but found a reference to
3705 something else instead. You can use the ref() function to find out what
3706 kind of ref it really was. See L<perlref>.
3708 =item Not a HASH reference
3710 (F) Perl was trying to evaluate a reference to a hash value, but found a
3711 reference to something else instead. You can use the ref() function to
3712 find out what kind of ref it really was. See L<perlref>.
3714 =item Not an ARRAY reference
3716 (F) Perl was trying to evaluate a reference to an array value, but found
3717 a reference to something else instead. You can use the ref() function
3718 to find out what kind of ref it really was. See L<perlref>.
3720 =item Not an unblessed ARRAY reference
3722 (F) You passed a reference to a blessed array to C<push>, C<shift> or
3723 another array function. These only accept unblessed array references
3724 or arrays beginning explicitly with C<@>.
3726 =item Not a SCALAR reference
3728 (F) Perl was trying to evaluate a reference to a scalar value, but found
3729 a reference to something else instead. You can use the ref() function
3730 to find out what kind of ref it really was. See L<perlref>.
3732 =item Not a subroutine reference
3734 (F) Perl was trying to evaluate a reference to a code value (that is, a
3735 subroutine), but found a reference to something else instead. You can
3736 use the ref() function to find out what kind of ref it really was. See
3739 =item Not a subroutine reference in overload table
3741 (F) An attempt was made to specify an entry in an overloading table that
3742 doesn't somehow point to a valid subroutine. See L<overload>.
3744 =item Not enough arguments for %s
3746 (F) The function requires more arguments than you specified.
3748 =item Not enough format arguments
3750 (W syntax) A format specified more picture fields than the next line
3751 supplied. See L<perlform>.
3755 (A) You've accidentally run your script through the Bourne shell instead
3756 of Perl. Check the #! line, or manually feed your script into Perl
3759 =item (?[...]) not valid in locale in regex; marked by S<<-- HERE> in m/%s/
3761 (F) C<(?[...])> cannot be used within the scope of a C<S<use locale>> or with
3762 an C</l> regular expression modifier, as that would require deferring
3763 to run-time the calculation of what it should evaluate to, and it is
3764 regex compile-time only.
3766 =item no UTC offset information; assuming local time is UTC
3768 (S) A warning peculiar to VMS. Perl was unable to find the local
3769 timezone offset, so it's assuming that local system time is equivalent
3770 to UTC. If it's not, define the logical name
3771 F<SYS$TIMEZONE_DIFFERENTIAL> to translate to the number of seconds which
3772 need to be added to UTC to get local time.
3774 =item NULL OP IN RUN
3776 (S debugging) Some internal routine called run() with a null opcode
3779 =item Null picture in formline
3781 (F) The first argument to formline must be a valid format picture
3782 specification. It was found to be empty, which probably means you
3783 supplied it an uninitialized value. See L<perlform>.
3787 (P) An attempt was made to realloc NULL.
3789 =item NULL regexp argument
3791 (P) The internal pattern matching routines blew it big time.
3793 =item NULL regexp parameter
3795 (P) The internal pattern matching routines are out of their gourd.
3797 =item Number too long
3799 (F) Perl limits the representation of decimal numbers in programs to
3800 about 250 characters. You've exceeded that length. Future
3801 versions of Perl are likely to eliminate this arbitrary limitation. In
3802 the meantime, try using scientific notation (e.g. "1e6" instead of
3805 =item Number with no digits
3807 (F) Perl was looking for a number but found nothing that looked like
3808 a number. This happens, for example with C<\o{}>, with no number between
3811 =item Octal number > 037777777777 non-portable
3813 (W portable) The octal number you specified is larger than 2**32-1
3814 (4294967295) and therefore non-portable between systems. See
3815 L<perlport> for more on portability concerns.
3817 =item Odd name/value argument for subroutine
3819 (F) A subroutine using a slurpy hash parameter in its signature
3820 received an odd number of arguments to populate the hash. It requires
3821 the arguments to be paired, with the same number of keys as values.
3822 The caller of the subroutine is presumably at fault. Inconveniently,
3823 this error will be reported at the location of the subroutine, not that
3826 =item Odd number of arguments for overload::constant
3828 (W overload) The call to overload::constant contained an odd number of
3829 arguments. The arguments should come in pairs.
3831 =item Odd number of elements in anonymous hash
3833 (W misc) You specified an odd number of elements to initialize a hash,
3834 which is odd, because hashes come in key/value pairs.
3836 =item Odd number of elements in hash assignment
3838 (W misc) You specified an odd number of elements to initialize a hash,
3839 which is odd, because hashes come in key/value pairs.
3841 =item Offset outside string
3843 (F)(W layer) You tried to do a read/write/send/recv/seek operation
3844 with an offset pointing outside the buffer. This is difficult to
3845 imagine. The sole exceptions to this are that zero padding will
3846 take place when going past the end of the string when either
3847 C<sysread()>ing a file, or when seeking past the end of a scalar opened
3848 for I/O (in anticipation of future reads and to imitate the behaviour
3851 =item %s() on unopened %s
3853 (W unopened) An I/O operation was attempted on a filehandle that was
3854 never initialized. You need to do an open(), a sysopen(), or a socket()
3855 call, or call a constructor from the FileHandle package.
3857 =item -%s on unopened filehandle %s
3859 (W unopened) You tried to invoke a file test operator on a filehandle
3860 that isn't open. Check your control flow. See also L<perlfunc/-X>.
3864 (S internal) An internal warning that the grammar is screwed up.
3868 (S internal) An internal warning that the grammar is screwed up.
3870 =item Opening dirhandle %s also as a file
3872 (D io, deprecated) You used open() to associate a filehandle to
3873 a symbol (glob or scalar) that already holds a dirhandle.
3874 Although legal, this idiom might render your code confusing
3877 =item Opening filehandle %s also as a directory
3879 (D io, deprecated) You used opendir() to associate a dirhandle to
3880 a symbol (glob or scalar) that already holds a filehandle.
3881 Although legal, this idiom might render your code confusing
3884 =item Operand with no preceding operator in regex; marked by S<<-- HERE> in
3887 (F) You wrote something like
3889 (?[ \p{Digit} \p{Thai} ])
3891 There are two operands, but no operator giving how you want to combine
3894 =item Operation "%s": no method found, %s
3896 (F) An attempt was made to perform an overloaded operation for which no
3897 handler was defined. While some handlers can be autogenerated in terms
3898 of other handlers, there is no default handler for any operation, unless
3899 the C<fallback> overloading key is specified to be true. See L<overload>.
3901 =item Operation "%s" returns its argument for non-Unicode code point 0x%X
3903 (S non_unicode) You performed an operation requiring Unicode semantics
3904 on a code point that is not in Unicode, so what it should do is not
3905 defined. Perl has chosen to have it do nothing, and warn you.
3907 If the operation shown is "ToFold", it means that case-insensitive
3908 matching in a regular expression was done on the code point.
3910 If you know what you are doing you can turn off this warning by
3911 C<no warnings 'non_unicode';>.
3913 =item Operation "%s" returns its argument for UTF-16 surrogate U+%X
3915 (S surrogate) You performed an operation requiring Unicode
3916 semantics on a Unicode surrogate. Unicode frowns upon the use
3917 of surrogates for anything but storing strings in UTF-16, but
3918 semantics are (reluctantly) defined for the surrogates, and
3919 they are to do nothing for this operation. Because the use of
3920 surrogates can be dangerous, Perl warns.
3922 If the operation shown is "ToFold", it means that case-insensitive
3923 matching in a regular expression was done on the code point.
3925 If you know what you are doing you can turn off this warning by
3926 C<no warnings 'surrogate';>.
3928 =item Operator or semicolon missing before %s
3930 (S ambiguous) You used a variable or subroutine call where the parser
3931 was expecting an operator. The parser has assumed you really meant to
3932 use an operator, but this is highly likely to be incorrect. For
3933 example, if you say "*foo *foo" it will be interpreted as if you said
3936 =item Optional parameter lacks default expression
3938 (F) In a subroutine signature, you wrote something like "$a =", making a
3939 named optional parameter without a default value. A nameless optional
3940 parameter is permitted to have no default value, but a named one must
3941 have a specific default. You probably want "$a = undef".
3943 =item "our" variable %s redeclared
3945 (W misc) You seem to have already declared the same global once before
3946 in the current lexical scope.
3948 =item Out of memory!
3950 (X) The malloc() function returned 0, indicating there was insufficient
3951 remaining memory (or virtual memory) to satisfy the request. Perl has
3952 no option but to exit immediately.
3954 At least in Unix you may be able to get past this by increasing your
3955 process datasize limits: in csh/tcsh use C<limit> and
3956 C<limit datasize n> (where C<n> is the number of kilobytes) to check
3957 the current limits and change them, and in ksh/bash/zsh use C<ulimit -a>
3958 and C<ulimit -d n>, respectively.
3960 =item Out of memory during %s extend
3962 (X) An attempt was made to extend an array, a list, or a string beyond
3963 the largest possible memory allocation.
3965 =item Out of memory during "large" request for %s
3967 (F) The malloc() function returned 0, indicating there was insufficient
3968 remaining memory (or virtual memory) to satisfy the request. However,
3969 the request was judged large enough (compile-time default is 64K), so a
3970 possibility to shut down by trapping this error is granted.
3972 =item Out of memory during request for %s
3974 (X)(F) The malloc() function returned 0, indicating there was
3975 insufficient remaining memory (or virtual memory) to satisfy the
3978 The request was judged to be small, so the possibility to trap it
3979 depends on the way perl was compiled. By default it is not trappable.
3980 However, if compiled for this, Perl may use the contents of C<$^M> as an
3981 emergency pool after die()ing with this message. In this case the error
3982 is trappable I<once>, and the error message will include the line and file
3983 where the failed request happened.
3985 =item Out of memory during ridiculously large request
3987 (F) You can't allocate more than 2^31+"small amount" bytes. This error
3988 is most likely to be caused by a typo in the Perl program. e.g.,
3989 C<$arr[time]> instead of C<$arr[$time]>.
3991 =item Out of memory for yacc stack
3993 (F) The yacc parser wanted to grow its stack so it could continue
3994 parsing, but realloc() wouldn't give it more memory, virtual or
3997 =item '.' outside of string in pack
3999 (F) The argument to a '.' in your template tried to move the working
4000 position to before the start of the packed string being built.
4002 =item '@' outside of string in unpack
4004 (F) You had a template that specified an absolute position outside
4005 the string being unpacked. See L<perlfunc/pack>.
4007 =item '@' outside of string with malformed UTF-8 in unpack
4009 (F) You had a template that specified an absolute position outside
4010 the string being unpacked. The string being unpacked was also invalid
4011 UTF-8. See L<perlfunc/pack>.
4013 =item overload arg '%s' is invalid
4015 (W overload) The L<overload> pragma was passed an argument it did not
4016 recognize. Did you mistype an operator?
4018 =item Overloaded dereference did not return a reference
4020 (F) An object with an overloaded dereference operator was dereferenced,
4021 but the overloaded operation did not return a reference. See
4024 =item Overloaded qr did not return a REGEXP
4026 (F) An object with a C<qr> overload was used as part of a match, but the
4027 overloaded operation didn't return a compiled regexp. See L<overload>.
4029 =item %s package attribute may clash with future reserved word: %s
4031 (W reserved) A lowercase attribute name was used that had a
4032 package-specific handler. That name might have a meaning to Perl itself
4033 some day, even though it doesn't yet. Perhaps you should use a
4034 mixed-case attribute name, instead. See L<attributes>.
4036 =item pack/unpack repeat count overflow
4038 (F) You can't specify a repeat count so large that it overflows your
4039 signed integers. See L<perlfunc/pack>.
4043 (W io) A single call to write() produced more lines than can fit on a
4044 page. See L<perlform>.
4048 (P) An internal error.
4050 =item panic: attempt to call %s in %s
4052 (P) One of the file test operators entered a code branch that calls
4053 an ACL related-function, but that function is not available on this
4054 platform. Earlier checks mean that it should not be possible to
4055 enter this branch on this platform.
4057 =item panic: child pseudo-process was never scheduled
4059 (P) A child pseudo-process in the ithreads implementation on Windows
4060 was not scheduled within the time period allowed and therefore was not
4061 able to initialize properly.
4063 =item panic: ck_grep, type=%u
4065 (P) Failed an internal consistency check trying to compile a grep.
4067 =item panic: ck_split, type=%u
4069 (P) Failed an internal consistency check trying to compile a split.
4071 =item panic: corrupt saved stack index %ld
4073 (P) The savestack was requested to restore more localized values than
4074 there are in the savestack.
4076 =item panic: del_backref
4078 (P) Failed an internal consistency check while trying to reset a weak
4083 (P) We popped the context stack to an eval context, and then discovered
4084 it wasn't an eval context.
4086 =item panic: do_subst
4088 (P) The internal pp_subst() routine was called with invalid operational
4091 =item panic: do_trans_%s
4093 (P) The internal do_trans routines were called with invalid operational
4096 =item panic: fold_constants JMPENV_PUSH returned %d
4098 (P) While attempting folding constants an exception other than an C<eval>
4101 =item panic: frexp: %f
4103 (P) The library function frexp() failed, making printf("%f") impossible.
4105 =item panic: goto, type=%u, ix=%ld
4107 (P) We popped the context stack to a context with the specified label,
4108 and then discovered it wasn't a context we know how to do a goto in.
4110 =item panic: gp_free failed to free glob pointer
4112 (P) The internal routine used to clear a typeglob's entries tried
4113 repeatedly, but each time something re-created entries in the glob.
4114 Most likely the glob contains an object with a reference back to
4115 the glob and a destructor that adds a new object to the glob.
4117 =item panic: INTERPCASEMOD, %s
4119 (P) The lexer got into a bad state at a case modifier.
4121 =item panic: INTERPCONCAT, %s
4123 (P) The lexer got into a bad state parsing a string with brackets.
4125 =item panic: kid popen errno read
4127 (F) A forked child returned an incomprehensible message about its errno.
4129 =item panic: last, type=%u
4131 (P) We popped the context stack to a block context, and then discovered
4132 it wasn't a block context.
4134 =item panic: leave_scope clearsv
4136 (P) A writable lexical variable became read-only somehow within the
4139 =item panic: leave_scope inconsistency %u
4141 (P) The savestack probably got out of sync. At least, there was an
4142 invalid enum on the top of it.
4144 =item panic: magic_killbackrefs
4146 (P) Failed an internal consistency check while trying to reset all weak
4147 references to an object.
4149 =item panic: malloc, %s
4151 (P) Something requested a negative number of bytes of malloc.
4153 =item panic: memory wrap
4155 (P) Something tried to allocate either more memory than possible or a
4158 =item panic: pad_alloc, %p!=%p
4160 (P) The compiler got confused about which scratch pad it was allocating
4161 and freeing temporaries and lexicals from.
4163 =item panic: pad_free curpad, %p!=%p
4165 (P) The compiler got confused about which scratch pad it was allocating
4166 and freeing temporaries and lexicals from.
4168 =item panic: pad_free po
4170 (P) A zero scratch pad offset was detected internally. An attempt was
4171 made to free a target that had not been allocated to begin with.
4173 =item panic: pad_reset curpad, %p!=%p
4175 (P) The compiler got confused about which scratch pad it was allocating
4176 and freeing temporaries and lexicals from.
4178 =item panic: pad_sv po
4180 (P) A zero scratch pad offset was detected internally. Most likely
4181 an operator needed a target but that target had not been allocated
4182 for whatever reason.
4184 =item panic: pad_swipe curpad, %p!=%p
4186 (P) The compiler got confused about which scratch pad it was allocating
4187 and freeing temporaries and lexicals from.
4189 =item panic: pad_swipe po
4191 (P) An invalid scratch pad offset was detected internally.
4193 =item panic: pp_iter, type=%u
4195 (P) The foreach iterator got called in a non-loop context frame.
4197 =item panic: pp_match%s
4199 (P) The internal pp_match() routine was called with invalid operational
4202 =item panic: pp_split, pm=%p, s=%p
4204 (P) Something terrible went wrong in setting up for the split.
4206 =item panic: realloc, %s
4208 (P) Something requested a negative number of bytes of realloc.
4210 =item panic: reference miscount on nsv in sv_replace() (%d != 1)
4212 (P) The internal sv_replace() function was handed a new SV with a
4213 reference count other than 1.
4215 =item panic: restartop in %s
4217 (P) Some internal routine requested a goto (or something like it), and
4218 didn't supply the destination.
4220 =item panic: return, type=%u
4222 (P) We popped the context stack to a subroutine or eval context, and
4223 then discovered it wasn't a subroutine or eval context.
4225 =item panic: scan_num, %s
4227 (P) scan_num() got called on something that wasn't a number.
4229 =item panic: Sequence (?{...}): no code block found in regex m/%s/
4231 (P) While compiling a pattern that has embedded (?{}) or (??{}) code
4232 blocks, perl couldn't locate the code block that should have already been
4233 seen and compiled by perl before control passed to the regex compiler.
4235 =item panic: strxfrm() gets absurd - a => %u, ab => %u
4237 (P) The interpreter's sanity check of the C function strxfrm() failed.
4238 In your current locale the returned transformation of the string "ab"
4239 is shorter than that of the string "a", which makes no sense.
4241 =item panic: sv_chop %s
4243 (P) The sv_chop() routine was passed a position that is not within the
4244 scalar's string buffer.
4246 =item panic: sv_insert, midend=%p, bigend=%p
4248 (P) The sv_insert() routine was told to remove more string than there
4251 =item panic: top_env
4253 (P) The compiler attempted to do a goto, or something weird like that.
4255 =item panic: unimplemented op %s (#%d) called
4257 (P) The compiler is screwed up and attempted to use an op that isn't
4258 permitted at run time.
4260 =item panic: utf16_to_utf8: odd bytelen
4262 (P) Something tried to call utf16_to_utf8 with an odd (as opposed
4263 to even) byte length.
4265 =item panic: utf16_to_utf8_reversed: odd bytelen
4267 (P) Something tried to call utf16_to_utf8_reversed with an odd (as opposed
4268 to even) byte length.
4270 =item panic: yylex, %s
4272 (P) The lexer got into a bad state while processing a case modifier.
4274 =item Parentheses missing around "%s" list
4276 (W parenthesis) You said something like
4282 my ($foo, $bar) = @_;
4284 Remember that "my", "our", "local" and "state" bind tighter than comma.
4286 =item Parsing code internal error (%s)
4288 (F) Parsing code supplied by an extension violated the parser's API in
4291 =item Passing malformed UTF-8 to "%s" is deprecated
4293 (D deprecated, utf8) This message indicates a bug either in the Perl
4294 core or in XS code. Such code was trying to find out if a character,
4295 allegedly stored internally encoded as UTF-8, was of a given type, such
4296 as being punctuation or a digit. But the character was not encoded in
4297 legal UTF-8. The C<%s> is replaced by a string that can be used by
4298 knowledgeable people to determine what the type being checked against
4299 was. If C<utf8> warnings are enabled, a further message is raised,
4300 giving details of the malformation.
4302 =item Pattern subroutine nesting without pos change exceeded limit in regex
4304 (F) You used a pattern that uses too many nested subpattern calls without
4305 consuming any text. Restructure the pattern so text is consumed before
4306 the nesting limit is exceeded.
4308 =item C<-p> destination: %s
4310 (F) An error occurred during the implicit output invoked by the C<-p>
4311 command-line switch. (This output goes to STDOUT unless you've
4312 redirected it with select().)
4314 =item Perl folding rules are not up-to-date for 0x%X; please use the perlbug
4315 utility to report; in regex; marked by S<<-- HERE> in m/%s/
4317 (S regexp) You used a regular expression with case-insensitive matching,
4318 and there is a bug in Perl in which the built-in regular expression
4319 folding rules are not accurate. This may lead to incorrect results.
4320 Please report this as a bug using the L<perlbug> utility.
4322 =item PerlIO layer ':win32' is experimental
4324 (S experimental::win32_perlio) The C<:win32> PerlIO layer is
4325 experimental. If you want to take the risk of using this layer,
4326 simply disable this warning:
4328 no warnings "experimental::win32_perlio";
4330 =item Perl_my_%s() not available
4332 (F) Your platform has very uncommon byte-order and integer size,
4333 so it was not possible to set up some or all fixed-width byte-order
4334 conversion functions. This is only a problem when you're using the
4335 '<' or '>' modifiers in (un)pack templates. See L<perlfunc/pack>.
4337 =item Perl %s required (did you mean %s?)--this is only %s, stopped
4339 (F) The code you are trying to run has asked for a newer version of
4340 Perl than you are running. Perhaps C<use 5.10> was written instead
4341 of C<use 5.010> or C<use v5.10>. Without the leading C<v>, the number is
4342 interpreted as a decimal, with every three digits after the
4343 decimal point representing a part of the version number. So 5.10
4344 is equivalent to v5.100.
4346 =item Perl %s required--this is only %s, stopped
4348 (F) The module in question uses features of a version of Perl more
4349 recent than the currently running version. How long has it been since
4350 you upgraded, anyway? See L<perlfunc/require>.
4352 =item PERL_SH_DIR too long
4354 (F) An error peculiar to OS/2. PERL_SH_DIR is the directory to find the
4355 C<sh>-shell in. See "PERL_SH_DIR" in L<perlos2>.
4357 =item PERL_SIGNALS illegal: "%s"
4359 (X) See L<perlrun/PERL_SIGNALS> for legal values.
4361 =item Perls since %s too modern--this is %s, stopped
4363 (F) The code you are trying to run claims it will not run
4364 on the version of Perl you are using because it is too new.
4365 Maybe the code needs to be updated, or maybe it is simply
4366 wrong and the version check should just be removed.
4368 =item perl: warning: Non hex character in '$ENV{PERL_HASH_SEED}', seed only partially set
4370 (S) PERL_HASH_SEED should match /^\s*(?:0x)?[0-9a-fA-F]+\s*\z/ but it
4371 contained a non hex character. This could mean you are not using the
4372 hash seed you think you are.
4374 =item perl: warning: Setting locale failed.
4376 (S) The whole warning message will look something like:
4378 perl: warning: Setting locale failed.
4379 perl: warning: Please check that your locale settings:
4382 are supported and installed on your system.
4383 perl: warning: Falling back to the standard locale ("C").
4385 Exactly what were the failed locale settings varies. In the above the
4386 settings were that the LC_ALL was "En_US" and the LANG had no value.
4387 This error means that Perl detected that you and/or your operating
4388 system supplier and/or system administrator have set up the so-called
4389 locale system but Perl could not use those settings. This was not
4390 dead serious, fortunately: there is a "default locale" called "C" that
4391 Perl can and will use, and the script will be run. Before you really
4392 fix the problem, however, you will get the same error message each
4393 time you run Perl. How to really fix the problem can be found in
4394 L<perllocale> section B<LOCALE PROBLEMS>.
4396 =item perl: warning: strange setting in '$ENV{PERL_PERTURB_KEYS}': '%s'
4398 (S) Perl was run with the environment variable PERL_PERTURB_KEYS defined
4399 but containing an unexpected value. The legal values of this setting
4402 Numeric | String | Result
4403 --------+---------------+-----------------------------------------
4404 0 | NO | Disables key traversal randomization
4405 1 | RANDOM | Enables full key traversal randomization
4406 2 | DETERMINISTIC | Enables repeatable key traversal
4409 Both numeric and string values are accepted, but note that string values are
4410 case sensitive. The default for this setting is "RANDOM" or 1.
4412 =item pid %x not a child
4414 (W exec) A warning peculiar to VMS. Waitpid() was asked to wait for a
4415 process which isn't a subprocess of the current process. While this is
4416 fine from VMS' perspective, it's probably not what you intended.
4418 =item 'P' must have an explicit size in unpack
4420 (F) The unpack format P must have an explicit size, not "*".
4422 =item pop on reference is experimental
4424 (S experimental::autoderef) C<pop> with a scalar argument is experimental
4425 and may change or be removed in a future Perl version. If you want to
4426 take the risk of using this feature, simply disable this warning:
4428 no warnings "experimental::autoderef";
4430 =item POSIX class [:%s:] unknown in regex; marked by S<< <-- HERE in m/%s/ >>
4432 (F) The class in the character class [: :] syntax is unknown. The S<<-- HERE>
4433 shows whereabouts in the regular expression the problem was discovered.
4434 Note that the POSIX character classes do B<not> have the C<is> prefix
4435 the corresponding C interfaces have: in other words, it's C<[[:print:]]>,
4436 not C<isprint>. See L<perlre>.
4438 =item POSIX getpgrp can't take an argument
4440 (F) Your system has POSIX getpgrp(), which takes no argument, unlike
4441 the BSD version, which takes a pid.
4443 =item POSIX syntax [%c %c] belongs inside character classes in regex; marked by
4444 S<<-- HERE> in m/%s/
4446 (W regexp) The character class constructs [: :], [= =], and [. .] go
4447 I<inside> character classes, the [] are part of the construct, for example:
4448 /[012[:alpha:]345]/. Note that [= =] and [. .] are not currently
4449 implemented; they are simply placeholders for future extensions and
4450 will cause fatal errors. The S<<-- HERE> shows whereabouts in the regular
4451 expression the problem was discovered. See L<perlre>.
4453 =item POSIX syntax [. .] is reserved for future extensions in regex; marked by
4454 S<<-- HERE> in m/%s/
4456 (F) Within regular expression character classes ([]) the syntax beginning
4457 with "[." and ending with ".]" is reserved for future extensions. If you
4458 need to represent those character sequences inside a regular expression
4459 character class, just quote the square brackets with the backslash: "\[."
4460 and ".\]". The S<<-- HERE> shows whereabouts in the regular expression the
4461 problem was discovered. See L<perlre>.
4463 =item POSIX syntax [= =] is reserved for future extensions in regex; marked by
4464 S<<-- HERE> in m/%s/
4466 (F) Within regular expression character classes ([]) the syntax beginning
4467 with "[=" and ending with "=]" is reserved for future extensions. If you
4468 need to represent those character sequences inside a regular expression
4469 character class, just quote the square brackets with the backslash: "\[="
4470 and "=\]". The S<<-- HERE> shows whereabouts in the regular expression the
4471 problem was discovered. See L<perlre>.
4473 =item Possible attempt to put comments in qw() list
4475 (W qw) qw() lists contain items separated by whitespace; as with literal
4476 strings, comment characters are not ignored, but are instead treated as
4477 literal data. (You may have used different delimiters than the
4478 parentheses shown here; braces are also frequently used.)
4480 You probably wrote something like this:
4487 when you should have written this:
4494 If you really want comments, build your list the
4495 old-fashioned way, with quotes and commas:
4499 'b', # another comment
4502 =item Possible attempt to separate words with commas
4504 (W qw) qw() lists contain items separated by whitespace; therefore
4505 commas aren't needed to separate the items. (You may have used
4506 different delimiters than the parentheses shown here; braces are also
4509 You probably wrote something like this:
4513 which puts literal commas into some of the list items. Write it without
4514 commas if you don't want them to appear in your data:
4518 =item Possible memory corruption: %s overflowed 3rd argument
4520 (F) An ioctl() or fcntl() returned more than Perl was bargaining for.
4521 Perl guesses a reasonable buffer size, but puts a sentinel byte at the
4522 end of the buffer just in case. This sentinel byte got clobbered, and
4523 Perl assumes that memory is now corrupted. See L<perlfunc/ioctl>.
4525 =item Possible precedence issue with control flow operator
4527 (W syntax) There is a possible problem with the mixing of a control
4528 flow operator (e.g. C<return>) and a low-precedence operator like
4531 sub { return $a or $b; }
4535 sub { (return $a) or $b; }
4537 Which is effectively just:
4541 Either use parentheses or the high-precedence variant of the operator.
4543 Note this may be also triggered for constructs like:
4547 =item Possible precedence problem on bitwise %c operator
4549 (W precedence) Your program uses a bitwise logical operator in conjunction
4550 with a numeric comparison operator, like this :
4552 if ($x & $y == 0) { ... }
4554 This expression is actually equivalent to C<$x & ($y == 0)>, due to the
4555 higher precedence of C<==>. This is probably not what you want. (If you
4556 really meant to write this, disable the warning, or, better, put the
4557 parentheses explicitly and write C<$x & ($y == 0)>).
4559 =item Possible unintended interpolation of $\ in regex
4561 (W ambiguous) You said something like C<m/$\/> in a regex.
4562 The regex C<m/foo$\s+bar/m> translates to: match the word 'foo', the output
4563 record separator (see L<perlvar/$\>) and the letter 's' (one time or more)
4564 followed by the word 'bar'.
4566 If this is what you intended then you can silence the warning by using
4567 C<m/${\}/> (for example: C<m/foo${\}s+bar/>).
4569 If instead you intended to match the word 'foo' at the end of the line
4570 followed by whitespace and the word 'bar' on the next line then you can use
4571 C<m/$(?)\/> (for example: C<m/foo$(?)\s+bar/>).
4573 =item Possible unintended interpolation of %s in string
4575 (W ambiguous) You said something like '@foo' in a double-quoted string
4576 but there was no array C<@foo> in scope at the time. If you wanted a
4577 literal @foo, then write it as \@foo; otherwise find out what happened
4578 to the array you apparently lost track of.
4580 =item Postfix dereference is experimental
4582 (S experimental::postderef) This warning is emitted if you use
4583 the experimental postfix dereference syntax. Simply suppress the
4584 warning if you want to use the feature, but know that in doing
4585 so you are taking the risk of using an experimental feature which
4586 may change or be removed in a future Perl version:
4588 no warnings "experimental::postderef";
4589 use feature "postderef", "postderef_qq";
4595 =item Precedence problem: open %s should be open(%s)
4597 (S precedence) The old irregular construct
4601 is now misinterpreted as
4605 because of the strict regularization of Perl 5's grammar into unary and
4606 list operators. (The old open was a little of both.) You must put
4607 parentheses around the filehandle, or use the new "or" operator instead
4610 =item Premature end of script headers
4614 =item printf() on closed filehandle %s
4616 (W closed) The filehandle you're writing to got itself closed sometime
4617 before now. Check your control flow.
4619 =item print() on closed filehandle %s
4621 (W closed) The filehandle you're printing on got itself closed sometime
4622 before now. Check your control flow.
4624 =item Process terminated by SIG%s
4626 (W) This is a standard message issued by OS/2 applications, while *nix
4627 applications die in silence. It is considered a feature of the OS/2
4628 port. One can easily disable this by appropriate sighandlers, see
4629 L<perlipc/"Signals">. See also "Process terminated by SIGTERM/SIGINT"
4632 =item Property '%s' is unknown in regex; marked by S<<-- HERE> in m/%s/
4634 (F) The named property which you specified via C<\p> or C<\P> is not one
4635 known to Perl. Perhaps you misspelled the name? See
4636 L<perluniprops/Properties accessible through \p{} and \P{}>
4637 for a complete list of available official
4638 properties. If it is a L<user-defined property|perlunicode/User-Defined Character Properties>
4639 it must have been defined by the time the regular expression is
4642 =item Prototype after '%c' for %s : %s
4644 (W illegalproto) A character follows % or @ in a prototype. This is
4645 useless, since % and @ gobble the rest of the subroutine arguments.
4647 =item Prototype mismatch: %s vs %s
4649 (S prototype) The subroutine being declared or defined had previously been
4650 declared or defined with a different function prototype.
4652 =item Prototype not terminated
4654 (F) You've omitted the closing parenthesis in a function prototype
4657 =item Prototype '%s' overridden by attribute 'prototype(%s)' in %s
4659 (W prototype) A prototype was declared in both the parentheses after
4660 the sub name and via the prototype attribute. The prototype in
4661 parentheses is useless, since it will be replaced by the prototype
4662 from the attribute before it's ever used.
4664 =item \p{} uses Unicode rules, not locale rules
4666 (W) You compiled a regular expression that contained a Unicode property
4667 match (C<\p> or C<\P>), but the regular expression is also being told to
4668 use the run-time locale, not Unicode. Instead, use a POSIX character
4669 class, which should know about the locale's rules.
4670 (See L<perlrecharclass/POSIX Character Classes>.)
4672 Even if the run-time locale is ISO 8859-1 (Latin1), which is a subset of
4673 Unicode, some properties will give results that are not valid for that
4676 Here are a couple of examples to help you see what's going on. If the
4677 locale is ISO 8859-7, the character at code point 0xD7 is the "GREEK
4678 CAPITAL LETTER CHI". But in Unicode that code point means the
4679 "MULTIPLICATION SIGN" instead, and C<\p> always uses the Unicode
4680 meaning. That means that C<\p{Alpha}> won't match, but C<[[:alpha:]]>
4681 should. Only in the Latin1 locale are all the characters in the same
4682 positions as they are in Unicode. But, even here, some properties give
4683 incorrect results. An example is C<\p{Changes_When_Uppercased}> which
4684 is true for "LATIN SMALL LETTER Y WITH DIAERESIS", but since the upper
4685 case of that character is not in Latin1, in that locale it doesn't
4686 change when upper cased.
4688 =item push on reference is experimental
4690 (S experimental::autoderef) C<push> with a scalar argument is experimental
4691 and may change or be removed in a future Perl version. If you want to
4692 take the risk of using this feature, simply disable this warning:
4694 no warnings "experimental::autoderef";
4696 =item Quantifier follows nothing in regex; marked by S<< <-- HERE in m/%s/ >>
4698 (F) You started a regular expression with a quantifier. Backslash it if
4699 you meant it literally. The S<<-- HERE> shows whereabouts in the regular
4700 expression the problem was discovered. See L<perlre>.
4702 =item Quantifier in {,} bigger than %d in regex; marked by S<<-- HERE> in
4705 (F) There is currently a limit to the size of the min and max values of
4706 the {min,max} construct. The S<<-- HERE> shows whereabouts in the regular
4707 expression the problem was discovered. See L<perlre>.
4709 =item Quantifier {n,m} with n > m can't match in regex
4711 =item Quantifier {n,m} with n > m can't match in regex; marked by
4712 S<<-- HERE> in m/%s/
4714 (W regexp) Minima should be less than or equal to maxima. If you really
4715 want your regexp to match something 0 times, just put {0}.
4717 =item Quantifier unexpected on zero-length expression in regex; marked by <--
4720 (W regexp) You applied a regular expression quantifier in a place where
4721 it makes no sense, such as on a zero-width assertion. Try putting the
4722 quantifier inside the assertion instead. For example, the way to match
4723 "abc" provided that it is followed by three repetitions of "xyz" is
4724 C</abc(?=(?:xyz){3})/>, not C</abc(?=xyz){3}/>.
4726 The <-- HERE shows whereabouts in the regular expression the problem was
4729 =item Range iterator outside integer range
4731 (F) One (or both) of the numeric arguments to the range operator ".."
4732 are outside the range which can be represented by integers internally.
4733 One possible workaround is to force Perl to use magical string increment
4734 by prepending "0" to your numbers.
4736 =item readdir() attempted on invalid dirhandle %s
4738 (W io) The dirhandle you're reading from is either closed or not really
4739 a dirhandle. Check your control flow.
4741 =item readline() on closed filehandle %s
4743 (W closed) The filehandle you're reading from got itself closed sometime
4744 before now. Check your control flow.
4746 =item read() on closed filehandle %s
4748 (W closed) You tried to read from a closed filehandle.
4750 =item read() on unopened filehandle %s
4752 (W unopened) You tried to read from a filehandle that was never opened.
4754 =item Reallocation too large: %x
4756 (F) You can't allocate more than 64K on an MS-DOS machine.
4758 =item realloc() of freed memory ignored
4760 (S malloc) An internal routine called realloc() on something that had
4763 =item Recompile perl with B<-D>DEBUGGING to use B<-D> switch
4765 (S debugging) You can't use the B<-D> option unless the code to produce
4766 the desired output is compiled into Perl, which entails some overhead,
4767 which is why it's currently left out of your copy.
4769 =item Recursive call to Perl_load_module in PerlIO_find_layer
4771 (P) It is currently not permitted to load modules when creating
4772 a filehandle inside an %INC hook. This can happen with C<open my
4773 $fh, '<', \$scalar>, which implicitly loads PerlIO::scalar. Try
4774 loading PerlIO::scalar explicitly first.
4776 =item Recursive inheritance detected in package '%s'
4778 (F) While calculating the method resolution order (MRO) of a package, Perl
4779 believes it found an infinite loop in the C<@ISA> hierarchy. This is a
4780 crude check that bails out after 100 levels of C<@ISA> depth.
4782 =item Redundant argument in %s
4784 (W redundant) You called a function with more arguments than other
4785 arguments you supplied indicated would be needed. Currently only
4786 emitted when a printf-type format required fewer arguments than were
4787 supplied, but might be used in the future for e.g. L<perlfunc/pack>.
4789 =item refcnt_dec: fd %d%s
4791 =item refcnt: fd %d%s
4793 =item refcnt_inc: fd %d%s
4795 (P) Perl's I/O implementation failed an internal consistency check. If
4796 you see this message, something is very wrong.
4798 =item Reference found where even-sized list expected
4800 (W misc) You gave a single reference where Perl was expecting a list
4801 with an even number of elements (for assignment to a hash). This
4802 usually means that you used the anon hash constructor when you meant
4803 to use parens. In any case, a hash requires key/value B<pairs>.
4805 %hash = { one => 1, two => 2, }; # WRONG
4806 %hash = [ qw/ an anon array / ]; # WRONG
4807 %hash = ( one => 1, two => 2, ); # right
4808 %hash = qw( one 1 two 2 ); # also fine
4810 =item Reference is already weak
4812 (W misc) You have attempted to weaken a reference that is already weak.
4813 Doing so has no effect.
4815 =item Reference to invalid group 0 in regex; marked by S<<-- HERE> in m/%s/
4817 (F) You used C<\g0> or similar in a regular expression. You may refer
4818 to capturing parentheses only with strictly positive integers
4819 (normal backreferences) or with strictly negative integers (relative
4820 backreferences). Using 0 does not make sense.
4822 =item Reference to nonexistent group in regex; marked by S<<-- HERE> in
4825 (F) You used something like C<\7> in your regular expression, but there are
4826 not at least seven sets of capturing parentheses in the expression. If
4827 you wanted to have the character with ordinal 7 inserted into the regular
4828 expression, prepend zeroes to make it three digits long: C<\007>
4830 The <-- HERE shows whereabouts in the regular expression the problem was
4833 =item Reference to nonexistent named group in regex; marked by S<<-- HERE>
4836 (F) You used something like C<\k'NAME'> or C<< \k<NAME> >> in your regular
4837 expression, but there is no corresponding named capturing parentheses
4838 such as C<(?'NAME'...)> or C<< (?<NAME>...) >>. Check if the name has been
4839 spelled correctly both in the backreference and the declaration.
4841 The <-- HERE shows whereabouts in the regular expression the problem was
4844 =item Reference to nonexistent or unclosed group in regex; marked by
4845 S<<-- HERE> in m/%s/
4847 (F) You used something like C<\g{-7}> in your regular expression, but there
4848 are not at least seven sets of closed capturing parentheses in the
4849 expression before where the C<\g{-7}> was located.
4851 The <-- HERE shows whereabouts in the regular expression the problem was
4854 =item regexp memory corruption
4856 (P) The regular expression engine got confused by what the regular
4857 expression compiler gave it.
4859 =item Regexp modifier "/%c" may appear a maximum of twice
4861 =item Regexp modifier "%c" may appear a maximum of twice in regex; marked
4862 by S<<-- HERE> in m/%s/
4864 (F) The regular expression pattern had too many occurrences
4865 of the specified modifier. Remove the extraneous ones.
4867 =item Regexp modifier "%c" may not appear after the "-" in regex; marked by <--
4870 (F) Turning off the given modifier has the side effect of turning on
4871 another one. Perl currently doesn't allow this. Reword the regular
4872 expression to use the modifier you want to turn on (and place it before
4873 the minus), instead of the one you want to turn off.
4875 =item Regexp modifier "/%c" may not appear twice
4877 =item Regexp modifier "%c" may not appear twice in regex; marked by <--
4880 (F) The regular expression pattern had too many occurrences
4881 of the specified modifier. Remove the extraneous ones.
4883 =item Regexp modifiers "/%c" and "/%c" are mutually exclusive
4885 =item Regexp modifiers "%c" and "%c" are mutually exclusive in regex;
4886 marked by S<<-- HERE> in m/%s/
4888 (F) The regular expression pattern had more than one of these
4889 mutually exclusive modifiers. Retain only the modifier that is
4890 supposed to be there.
4892 =item Regexp out of space in regex m/%s/
4894 (P) A "can't happen" error, because safemalloc() should have caught it
4897 =item Repeated format line will never terminate (~~ and @#)
4899 (F) Your format contains the ~~ repeat-until-blank sequence and a
4900 numeric field that will never go blank so that the repetition never
4901 terminates. You might use ^# instead. See L<perlform>.
4903 =item Replacement list is longer than search list
4905 (W misc) You have used a replacement list that is longer than the
4906 search list. So the additional elements in the replacement list
4909 =item '%s' resolved to '\o{%s}%d'
4911 (W misc, regexp) You wrote something like C<\08>, or C<\179> in a
4912 double-quotish string. All but the last digit is treated as a single
4913 character, specified in octal. The last digit is the next character in
4914 the string. To tell Perl that this is indeed what you want, you can use
4915 the C<\o{ }> syntax, or use exactly three digits to specify the octal
4918 =item Reversed %s= operator
4920 (W syntax) You wrote your assignment operator backwards. The = must
4921 always come last, to avoid ambiguity with subsequent unary operators.
4923 =item rewinddir() attempted on invalid dirhandle %s
4925 (W io) The dirhandle you tried to do a rewinddir() on is either closed
4926 or not really a dirhandle. Check your control flow.
4928 =item Scalars leaked: %d
4930 (S internal) Something went wrong in Perl's internal bookkeeping
4931 of scalars: not all scalar variables were deallocated by the time
4932 Perl exited. What this usually indicates is a memory leak, which
4933 is of course bad, especially if the Perl program is intended to be
4936 =item Scalar value @%s[%s] better written as $%s[%s]
4938 (W syntax) You've used an array slice (indicated by @) to select a
4939 single element of an array. Generally it's better to ask for a scalar
4940 value (indicated by $). The difference is that C<$foo[&bar]> always
4941 behaves like a scalar, both when assigning to it and when evaluating its
4942 argument, while C<@foo[&bar]> behaves like a list when you assign to it,
4943 and provides a list context to its subscript, which can do weird things
4944 if you're expecting only one subscript.
4946 On the other hand, if you were actually hoping to treat the array
4947 element as a list, you need to look into how references work, because
4948 Perl will not magically convert between scalars and lists for you. See
4951 =item Scalar value @%s{%s} better written as $%s{%s}
4953 (W syntax) You've used a hash slice (indicated by @) to select a single
4954 element of a hash. Generally it's better to ask for a scalar value
4955 (indicated by $). The difference is that C<$foo{&bar}> always behaves
4956 like a scalar, both when assigning to it and when evaluating its
4957 argument, while C<@foo{&bar}> behaves like a list when you assign to it,
4958 and provides a list context to its subscript, which can do weird things
4959 if you're expecting only one subscript.
4961 On the other hand, if you were actually hoping to treat the hash element
4962 as a list, you need to look into how references work, because Perl will
4963 not magically convert between scalars and lists for you. See
4966 =item Search pattern not terminated
4968 (F) The lexer couldn't find the final delimiter of a // or m{}
4969 construct. Remember that bracketing delimiters count nesting level.
4970 Missing the leading C<$> from a variable C<$m> may cause this error.
4972 Note that since Perl 5.10.0 a // can also be the I<defined-or>
4973 construct, not just the empty search pattern. Therefore code written
4974 in Perl 5.10.0 or later that uses the // as the I<defined-or> can be
4975 misparsed by pre-5.10.0 Perls as a non-terminated search pattern.
4977 =item seekdir() attempted on invalid dirhandle %s
4979 (W io) The dirhandle you are doing a seekdir() on is either closed or not
4980 really a dirhandle. Check your control flow.
4982 =item %sseek() on unopened filehandle
4984 (W unopened) You tried to use the seek() or sysseek() function on a
4985 filehandle that was either never opened or has since been closed.
4987 =item select not implemented
4989 (F) This machine doesn't implement the select() system call.
4991 =item Self-ties of arrays and hashes are not supported
4993 (F) Self-ties are of arrays and hashes are not supported in
4994 the current implementation.
4996 =item Semicolon seems to be missing
4998 (W semicolon) A nearby syntax error was probably caused by a missing
4999 semicolon, or possibly some other missing operator, such as a comma.
5001 =item semi-panic: attempt to dup freed string
5003 (S internal) The internal newSVsv() routine was called to duplicate a
5004 scalar that had previously been marked as free.
5006 =item sem%s not implemented
5008 (F) You don't have System V semaphore IPC on your system.
5010 =item send() on closed socket %s
5012 (W closed) The socket you're sending to got itself closed sometime
5013 before now. Check your control flow.
5015 =item Sequence (? incomplete in regex; marked by S<<-- HERE> in m/%s/
5017 (F) A regular expression ended with an incomplete extension (?. The
5018 S<<-- HERE> shows whereabouts in the regular expression the problem was
5019 discovered. See L<perlre>.
5021 =item Sequence (?%c...) not implemented in regex; marked by S<<-- HERE> in
5024 (F) A proposed regular expression extension has the character reserved
5025 but has not yet been written. The S<<-- HERE> shows whereabouts in the
5026 regular expression the problem was discovered. See L<perlre>.
5028 =item Sequence (?%s...) not recognized in regex; marked by S<<-- HERE> in
5031 (F) You used a regular expression extension that doesn't make sense.
5032 The S<<-- HERE> shows whereabouts in the regular expression the problem was
5033 discovered. This may happen when using the C<(?^...)> construct to tell
5034 Perl to use the default regular expression modifiers, and you
5035 redundantly specify a default modifier. For other
5036 causes, see L<perlre>.
5038 =item Sequence (?#... not terminated in regex m/%s/
5040 (F) A regular expression comment must be terminated by a closing
5041 parenthesis. Embedded parentheses aren't allowed. See
5044 =item Sequence (?&... not terminated in regex; marked by S<<-- HERE> in
5047 (F) A named reference of the form C<(?&...)> was missing the final
5048 closing parenthesis after the name. The S<<-- HERE> shows whereabouts
5049 in the regular expression the problem was discovered.
5051 =item Sequence (?%c... not terminated in regex; marked by S<<-- HERE>
5054 (F) A named group of the form C<(?'...')> or C<< (?<...>) >> was missing the final
5055 closing quote or angle bracket. The S<<-- HERE> shows whereabouts in the
5056 regular expression the problem was discovered.
5058 =item Sequence (?(%c... not terminated in regex; marked by S<<-- HERE>
5061 (F) A named reference of the form C<(?('...')...)> or C<< (?(<...>)...) >> was
5062 missing the final closing quote or angle bracket after the name. The
5063 S<<-- HERE> shows whereabouts in the regular expression the problem was
5066 =item Sequence "\c{" invalid
5068 (F) These three characters may not appear in sequence in a
5069 double-quotish context. This message is raised only on non-ASCII
5070 platforms (a different error message is output on ASCII ones). If you
5071 were intending to specify a control character with this sequence, you'll
5072 have to use a different way to specify it.
5074 =item Sequence \%s... not terminated in regex; marked by S<<-- HERE> in
5077 (F) The regular expression expects a mandatory argument following the escape
5078 sequence and this has been omitted or incorrectly written.
5080 =item Sequence (?{...}) not terminated with ')'
5082 (F) The end of the perl code contained within the {...} must be
5083 followed immediately by a ')'.
5085 =item Sequence ?P=... not terminated in regex; marked by S<<-- HERE> in
5088 (F) A named reference of the form C<(?P=...)> was missing the final
5089 closing parenthesis after the name. The S<<-- HERE> shows whereabouts
5090 in the regular expression the problem was discovered.
5092 =item Sequence (?R) not terminated in regex m/%s/
5094 (F) An C<(?R)> or C<(?0)> sequence in a regular expression was missing the
5097 =item Server error (a.k.a. "500 Server error")
5099 (A) This is the error message generally seen in a browser window
5100 when trying to run a CGI program (including SSI) over the web. The
5101 actual error text varies widely from server to server. The most
5102 frequently-seen variants are "500 Server error", "Method (something)
5103 not permitted", "Document contains no data", "Premature end of script
5104 headers", and "Did not produce a valid header".
5106 B<This is a CGI error, not a Perl error>.
5108 You need to make sure your script is executable, is accessible by
5109 the user CGI is running the script under (which is probably not the
5110 user account you tested it under), does not rely on any environment
5111 variables (like PATH) from the user it isn't running under, and isn't
5112 in a location where the CGI server can't find it, basically, more or
5113 less. Please see the following for more information:
5115 http://www.perl.org/CGI_MetaFAQ.html
5116 http://www.htmlhelp.org/faq/cgifaq.html
5117 http://www.w3.org/Security/Faq/
5119 You should also look at L<perlfaq9>.
5121 =item setegid() not implemented
5123 (F) You tried to assign to C<$)>, and your operating system doesn't
5124 support the setegid() system call (or equivalent), or at least Configure
5127 =item seteuid() not implemented
5129 (F) You tried to assign to C<< $> >>, and your operating system doesn't
5130 support the seteuid() system call (or equivalent), or at least Configure
5133 =item setpgrp can't take arguments
5135 (F) Your system has the setpgrp() from BSD 4.2, which takes no
5136 arguments, unlike POSIX setpgid(), which takes a process ID and process
5139 =item setrgid() not implemented
5141 (F) You tried to assign to C<$(>, and your operating system doesn't
5142 support the setrgid() system call (or equivalent), or at least Configure
5145 =item setruid() not implemented
5147 (F) You tried to assign to C<$<>, and your operating system doesn't
5148 support the setruid() system call (or equivalent), or at least Configure
5151 =item setsockopt() on closed socket %s
5153 (W closed) You tried to set a socket option on a closed socket. Did you
5154 forget to check the return value of your socket() call? See
5155 L<perlfunc/setsockopt>.
5157 =item Setting $/ to a reference to %s as a form of slurp is deprecated, treating as undef
5159 (W deprecated) You assigned a reference to a scalar to C<$/> where the
5160 referenced item is not a positive integer. In older perls this B<appeared>
5161 to work the same as setting it to C<undef> but was in fact internally
5162 different, less efficient and with very bad luck could have resulted in
5163 your file being split by a stringified form of the reference.
5165 In Perl 5.20.0 this was changed so that it would be B<exactly> the same as
5166 setting C<$/> to undef, with the exception that this warning would be
5169 You are recommended to change your code to set C<$/> to C<undef> explicitly
5170 if you wish to slurp the file. In future versions of Perl assigning
5171 a reference to will throw a fatal error.
5173 =item Setting $/ to %s reference is forbidden
5175 (F) You tried to assign a reference to a non integer to C<$/>. In older
5176 Perls this would have behaved similarly to setting it to a reference to
5177 a positive integer, where the integer was the address of the reference.
5178 As of Perl 5.20.0 this is a fatal error, to allow future versions of Perl
5179 to use non-integer refs for more interesting purposes.
5181 =item shift on reference is experimental
5183 (S experimental::autoderef) C<shift> with a scalar argument is experimental
5184 and may change or be removed in a future Perl version. If you want to
5185 take the risk of using this feature, simply disable this warning:
5187 no warnings "experimental::autoderef";
5189 =item shm%s not implemented
5191 (F) You don't have System V shared memory IPC on your system.
5193 =item !=~ should be !~
5195 (W syntax) The non-matching operator is !~, not !=~. !=~ will be
5196 interpreted as the != (numeric not equal) and ~ (1's complement)
5197 operators: probably not what you intended.
5199 =item /%s/ should probably be written as "%s"
5201 (W syntax) You have used a pattern where Perl expected to find a string,
5202 as in the first argument to C<join>. Perl will treat the true or false
5203 result of matching the pattern against $_ as the string, which is
5204 probably not what you had in mind.
5206 =item shutdown() on closed socket %s
5208 (W closed) You tried to do a shutdown on a closed socket. Seems a bit
5211 =item SIG%s handler "%s" not defined
5213 (W signal) The signal handler named in %SIG doesn't, in fact, exist.
5214 Perhaps you put it into the wrong package?
5216 =item Slab leaked from cv %p
5218 (S) If you see this message, then something is seriously wrong with the
5219 internal bookkeeping of op trees. An op tree needed to be freed after
5220 a compilation error, but could not be found, so it was leaked instead.
5222 =item sleep(%u) too large
5224 (W overflow) You called C<sleep> with a number that was larger than
5225 it can reliably handle and C<sleep> probably slept for less time than
5228 =item Slurpy parameter not last
5230 (F) In a subroutine signature, you put something after a slurpy (array or
5231 hash) parameter. The slurpy parameter takes all the available arguments,
5232 so there can't be any left to fill later parameters.
5234 =item Smart matching a non-overloaded object breaks encapsulation
5236 (F) You should not use the C<~~> operator on an object that does not
5237 overload it: Perl refuses to use the object's underlying structure
5238 for the smart match.
5240 =item Smartmatch is experimental
5242 (S experimental::smartmatch) This warning is emitted if you
5243 use the smartmatch (C<~~>) operator. This is currently an experimental
5244 feature, and its details are subject to change in future releases of
5245 Perl. Particularly, its current behavior is noticed for being
5246 unnecessarily complex and unintuitive, and is very likely to be
5249 =item sort is now a reserved word
5251 (F) An ancient error message that almost nobody ever runs into anymore.
5252 But before sort was a keyword, people sometimes used it as a filehandle.
5254 =item Sort subroutine didn't return single value
5256 (F) A sort comparison subroutine written in XS must return exactly one
5257 item. See L<perlfunc/sort>.
5259 =item Source filters apply only to byte streams
5261 (F) You tried to activate a source filter (usually by loading a
5262 source filter module) within a string passed to C<eval>. This is
5263 not permitted under the C<unicode_eval> feature. Consider using
5264 C<evalbytes> instead. See L<feature>.
5266 =item splice() offset past end of array
5268 (W misc) You attempted to specify an offset that was past the end of
5269 the array passed to splice(). Splicing will instead commence at the
5270 end of the array, rather than past it. If this isn't what you want,
5271 try explicitly pre-extending the array by assigning $#array = $offset.
5272 See L<perlfunc/splice>.
5274 =item splice on reference is experimental
5276 (S experimental::autoderef) C<splice> with a scalar argument
5277 is experimental and may change or be removed in a future
5278 Perl version. If you want to take the risk of using this
5279 feature, simply disable this warning:
5281 no warnings "experimental::autoderef";
5285 (P) The split was looping infinitely. (Obviously, a split shouldn't
5286 iterate more times than there are characters of input, which is what
5287 happened.) See L<perlfunc/split>.
5289 =item Statement unlikely to be reached
5291 (W exec) You did an exec() with some statement after it other than a
5292 die(). This is almost always an error, because exec() never returns
5293 unless there was a failure. You probably wanted to use system()
5294 instead, which does return. To suppress this warning, put the exec() in
5297 =item "state" subroutine %s can't be in a package
5299 (F) Lexically scoped subroutines aren't in a package, so it doesn't make
5300 sense to try to declare one with a package qualifier on the front.
5302 =item "state %s" used in sort comparison
5304 (W syntax) The package variables $a and $b are used for sort comparisons.
5305 You used $a or $b in as an operand to the C<< <=> >> or C<cmp> operator inside a
5306 sort comparison block, and the variable had earlier been declared as a
5307 lexical variable. Either qualify the sort variable with the package
5308 name, or rename the lexical variable.
5310 =item "state" variable %s can't be in a package
5312 (F) Lexically scoped variables aren't in a package, so it doesn't make
5313 sense to try to declare one with a package qualifier on the front. Use
5314 local() if you want to localize a package variable.
5316 =item stat() on unopened filehandle %s
5318 (W unopened) You tried to use the stat() function on a filehandle that
5319 was either never opened or has since been closed.
5321 =item Strings with code points over 0xFF may not be mapped into in-memory file handles
5323 (W utf8) You tried to open a reference to a scalar for read or append
5324 where the scalar contained code points over 0xFF. In-memory files
5325 model on-disk files and can only contain bytes.
5327 =item Stub found while resolving method "%s" overloading "%s" in package "%s"
5329 (P) Overloading resolution over @ISA tree may be broken by importation
5330 stubs. Stubs should never be implicitly created, but explicit calls to
5331 C<can> may break this.
5333 =item Subroutine "&%s" is not available
5335 (W closure) During compilation, an inner named subroutine or eval is
5336 attempting to capture an outer lexical subroutine that is not currently
5337 available. This can happen for one of two reasons. First, the lexical
5338 subroutine may be declared in an outer anonymous subroutine that has
5339 not yet been created. (Remember that named subs are created at compile
5340 time, while anonymous subs are created at run-time.) For example,
5342 sub { my sub a {...} sub f { \&a } }
5344 At the time that f is created, it can't capture the current "a" sub,
5345 since the anonymous subroutine hasn't been created yet. Conversely, the
5346 following won't give a warning since the anonymous subroutine has by now
5347 been created and is live:
5349 sub { my sub a {...} eval 'sub f { \&a }' }->();
5351 The second situation is caused by an eval accessing a lexical subroutine
5352 that has gone out of scope, for example,
5360 Here, when the '\&a' in the eval is being compiled, f() is not currently
5361 being executed, so its &a is not available for capture.
5363 =item "%s" subroutine &%s masks earlier declaration in same %s
5365 (W misc) A "my" or "state" subroutine has been redeclared in the
5366 current scope or statement, effectively eliminating all access to
5367 the previous instance. This is almost always a typographical error.
5368 Note that the earlier subroutine will still exist until the end of
5369 the scope or until all closure references to it are destroyed.
5371 =item Subroutine %s redefined
5373 (W redefine) You redefined a subroutine. To suppress this warning, say
5376 no warnings 'redefine';
5377 eval "sub name { ... }";
5380 =item Substitution loop
5382 (P) The substitution was looping infinitely. (Obviously, a substitution
5383 shouldn't iterate more times than there are characters of input, which
5384 is what happened.) See the discussion of substitution in
5385 L<perlop/"Regexp Quote-Like Operators">.
5387 =item Substitution pattern not terminated
5389 (F) The lexer couldn't find the interior delimiter of an s/// or s{}{}
5390 construct. Remember that bracketing delimiters count nesting level.
5391 Missing the leading C<$> from variable C<$s> may cause this error.
5393 =item Substitution replacement not terminated
5395 (F) The lexer couldn't find the final delimiter of an s/// or s{}{}
5396 construct. Remember that bracketing delimiters count nesting level.
5397 Missing the leading C<$> from variable C<$s> may cause this error.
5399 =item substr outside of string
5401 (W substr)(F) You tried to reference a substr() that pointed outside of
5402 a string. That is, the absolute value of the offset was larger than the
5403 length of the string. See L<perlfunc/substr>. This warning is fatal if
5404 substr is used in an lvalue context (as the left hand side of an
5405 assignment or as a subroutine argument for example).
5407 =item sv_upgrade from type %d down to type %d
5409 (P) Perl tried to force the upgrade of an SV to a type which was actually
5410 inferior to its current type.
5412 =item SWASHNEW didn't return an HV ref
5414 (P) Something went wrong internally when Perl was trying to look up
5417 =item Switch (?(condition)... contains too many branches in regex; marked by
5418 S<<-- HERE> in m/%s/
5420 (F) A (?(condition)if-clause|else-clause) construct can have at most
5421 two branches (the if-clause and the else-clause). If you want one or
5422 both to contain alternation, such as using C<this|that|other>, enclose
5423 it in clustering parentheses:
5425 (?(condition)(?:this|that|other)|else-clause)
5427 The S<<-- HERE> shows whereabouts in the regular expression the problem
5428 was discovered. See L<perlre>.
5430 =item Switch condition not recognized in regex; marked by S<<-- HERE> in
5433 (F) The condition part of a (?(condition)if-clause|else-clause) construct
5434 is not known. The condition must be one of the following:
5436 (1) (2) ... true if 1st, 2nd, etc., capture matched
5437 (<NAME>) ('NAME') true if named capture matched
5438 (?=...) (?<=...) true if subpattern matches
5439 (?!...) (?<!...) true if subpattern fails to match
5440 (?{ CODE }) true if code returns a true value
5441 (R) true if evaluating inside recursion
5442 (R1) (R2) ... true if directly inside capture group 1, 2, etc.
5443 (R&NAME) true if directly inside named capture
5444 (DEFINE) always false; for defining named subpatterns
5446 The <-- HERE shows whereabouts in the regular expression the problem was
5447 discovered. See L<perlre>.
5449 =item Switch (?(condition)... not terminated in regex; marked by
5450 S<<-- HERE> in m/%s/
5452 (F) You omitted to close a (?(condition)...) block somewhere
5453 in the pattern. Add a closing parenthesis in the appropriate
5454 position. See L<perlre>.
5456 =item switching effective %s is not implemented
5458 (F) While under the C<use filetest> pragma, we cannot switch the real
5459 and effective uids or gids.
5463 (F) Probably means you had a syntax error. Common reasons include:
5465 A keyword is misspelled.
5466 A semicolon is missing.
5468 An opening or closing parenthesis is missing.
5469 An opening or closing brace is missing.
5470 A closing quote is missing.
5472 Often there will be another error message associated with the syntax
5473 error giving more information. (Sometimes it helps to turn on B<-w>.)
5474 The error message itself often tells you where it was in the line when
5475 it decided to give up. Sometimes the actual error is several tokens
5476 before this, because Perl is good at understanding random input.
5477 Occasionally the line number may be misleading, and once in a blue moon
5478 the only way to figure out what's triggering the error is to call
5479 C<perl -c> repeatedly, chopping away half the program each time to see
5480 if the error went away. Sort of the cybernetic version of S<20 questions>.
5482 =item syntax error at line %d: '%s' unexpected
5484 (A) You've accidentally run your script through the Bourne shell instead
5485 of Perl. Check the #! line, or manually feed your script into Perl
5488 =item syntax error in file %s at line %d, next 2 tokens "%s"
5490 (F) This error is likely to occur if you run a perl5 script through
5491 a perl4 interpreter, especially if the next 2 tokens are "use strict"
5492 or "my $var" or "our $var".
5494 =item Syntax error in (?[...]) in regex m/%s/
5496 (F) Perl could not figure out what you meant inside this construct; this
5497 notifies you that it is giving up trying.
5501 (F) The final summary message when a C<perl -c> succeeds.
5503 =item sysread() on closed filehandle %s
5505 (W closed) You tried to read from a closed filehandle.
5507 =item sysread() on unopened filehandle %s
5509 (W unopened) You tried to read from a filehandle that was never opened.
5511 =item System V %s is not implemented on this machine
5513 (F) You tried to do something with a function beginning with "sem",
5514 "shm", or "msg" but that System V IPC is not implemented in your
5515 machine. In some machines the functionality can exist but be
5516 unconfigured. Consult your system support.
5518 =item syswrite() on closed filehandle %s
5520 (W closed) The filehandle you're writing to got itself closed sometime
5521 before now. Check your control flow.
5523 =item C<-T> and C<-B> not implemented on filehandles
5525 (F) Perl can't peek at the stdio buffer of filehandles when it doesn't
5526 know about your kind of stdio. You'll have to use a filename instead.
5528 =item Target of goto is too deeply nested
5530 (F) You tried to use C<goto> to reach a label that was too deeply nested
5531 for Perl to reach. Perl is doing you a favor by refusing.
5533 =item telldir() attempted on invalid dirhandle %s
5535 (W io) The dirhandle you tried to telldir() is either closed or not really
5536 a dirhandle. Check your control flow.
5538 =item tell() on unopened filehandle
5540 (W unopened) You tried to use the tell() function on a filehandle that
5541 was either never opened or has since been closed.
5543 =item That use of $[ is unsupported
5545 (F) Assignment to C<$[> is now strictly circumscribed, and interpreted
5546 as a compiler directive. You may say only one of
5555 This is to prevent the problem of one module changing the array base out
5556 from under another module inadvertently. See L<perlvar/$[> and L<arybase>.
5558 =item The crypt() function is unimplemented due to excessive paranoia.
5560 (F) Configure couldn't find the crypt() function on your machine,
5561 probably because your vendor didn't supply it, probably because they
5562 think the U.S. Government thinks it's a secret, or at least that they
5563 will continue to pretend that it is. And if you quote me on that, I
5566 =item The %s function is unimplemented
5568 (F) The function indicated isn't implemented on this architecture,
5569 according to the probings of Configure.
5571 =item The lexical_subs feature is experimental
5573 (S experimental::lexical_subs) This warning is emitted if you
5574 declare a sub with C<my> or C<state>. Simply suppress the warning
5575 if you want to use the feature, but know that in doing so you
5576 are taking the risk of using an experimental feature which may
5577 change or be removed in a future Perl version:
5579 no warnings "experimental::lexical_subs";
5580 use feature "lexical_subs";
5583 =item The regex_sets feature is experimental
5585 (S experimental::regex_sets) This warning is emitted if you
5586 use the syntax S<C<(?[ ])>> in a regular expression.
5587 The details of this feature are subject to change.
5588 if you want to use it, but know that in doing so you
5589 are taking the risk of using an experimental feature which may
5590 change in a future Perl version, you can do this to silence the
5593 no warnings "experimental::regex_sets";
5595 =item The signatures feature is experimental
5597 (S experimental::signatures) This warning is emitted if you unwrap a
5598 subroutine's arguments using a signature. Simply suppress the warning
5599 if you want to use the feature, but know that in doing so you are taking
5600 the risk of using an experimental feature which may change or be removed
5601 in a future Perl version:
5603 no warnings "experimental::signatures";
5604 use feature "signatures";
5605 sub foo ($left, $right) { ... }
5607 =item The stat preceding %s wasn't an lstat
5609 (F) It makes no sense to test the current stat buffer for symbolic
5610 linkhood if the last stat that wrote to the stat buffer already went
5611 past the symlink to get to the real file. Use an actual filename
5614 =item The 'unique' attribute may only be applied to 'our' variables
5616 (F) This attribute was never supported on C<my> or C<sub> declarations.
5618 =item This Perl can't reset CRTL environ elements (%s)
5620 =item This Perl can't set CRTL environ elements (%s=%s)
5622 (W internal) Warnings peculiar to VMS. You tried to change or delete an
5623 element of the CRTL's internal environ array, but your copy of Perl
5624 wasn't built with a CRTL that contained the setenv() function. You'll
5625 need to rebuild Perl with a CRTL that does, or redefine
5626 F<PERL_ENV_TABLES> (see L<perlvms>) so that the environ array isn't the
5627 target of the change to
5628 %ENV which produced the warning.
5630 =item This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().
5632 (F) Something has attempted to use an internal API call which
5633 depends on Perl being compiled with the default support for randomized hash
5634 key traversal, but this Perl has been compiled without it. You should
5635 report this warning to the relevant upstream party, or recompile perl
5636 with default options.
5638 =item times not implemented
5640 (F) Your version of the C library apparently doesn't do times(). I
5641 suspect you're not running on Unix.
5643 =item "-T" is on the #! line, it must also be used on the command line
5645 (X) The #! line (or local equivalent) in a Perl script contains
5646 the B<-T> option (or the B<-t> option), but Perl was not invoked with
5647 B<-T> in its command line. This is an error because, by the time
5648 Perl discovers a B<-T> in a script, it's too late to properly taint
5649 everything from the environment. So Perl gives up.
5651 If the Perl script is being executed as a command using the #!
5652 mechanism (or its local equivalent), this error can usually be
5653 fixed by editing the #! line so that the B<-%c> option is a part of
5654 Perl's first argument: e.g. change C<perl -n -%c> to C<perl -%c -n>.
5656 If the Perl script is being executed as C<perl scriptname>, then the
5657 B<-%c> option must appear on the command line: C<perl -%c scriptname>.
5659 =item To%s: illegal mapping '%s'
5661 (F) You tried to define a customized To-mapping for lc(), lcfirst,
5662 uc(), or ucfirst() (or their string-inlined versions), but you
5663 specified an illegal mapping.
5664 See L<perlunicode/"User-Defined Character Properties">.
5666 =item Too deeply nested ()-groups
5668 (F) Your template contains ()-groups with a ridiculously deep nesting level.
5670 =item Too few args to syscall
5672 (F) There has to be at least one argument to syscall() to specify the
5673 system call to call, silly dilly.
5675 =item Too few arguments for subroutine
5677 (F) A subroutine using a signature received fewer arguments than required
5678 by the signature. The caller of the subroutine is presumably at fault.
5679 Inconveniently, this error will be reported at the location of the
5680 subroutine, not that of the caller.
5682 =item Too late for "-%s" option
5684 (X) The #! line (or local equivalent) in a Perl script contains the
5685 B<-M>, B<-m> or B<-C> option.
5687 In the case of B<-M> and B<-m>, this is an error because those options
5688 are not intended for use inside scripts. Use the C<use> pragma instead.
5690 The B<-C> option only works if it is specified on the command line as
5691 well (with the same sequence of letters or numbers following). Either
5692 specify this option on the command line, or, if your system supports
5693 it, make your script executable and run it directly instead of passing
5696 =item Too late to run %s block
5698 (W void) A CHECK or INIT block is being defined during run time proper,
5699 when the opportunity to run them has already passed. Perhaps you are
5700 loading a file with C<require> or C<do> when you should be using C<use>
5701 instead. Or perhaps you should put the C<require> or C<do> inside a
5704 =item Too many args to syscall
5706 (F) Perl supports a maximum of only 14 args to syscall().
5708 =item Too many arguments for %s
5710 (F) The function requires fewer arguments than you specified.
5712 =item Too many arguments for subroutine
5714 (F) A subroutine using a signature received more arguments than required
5715 by the signature. The caller of the subroutine is presumably at fault.
5716 Inconveniently, this error will be reported at the location of the
5717 subroutine, not that of the caller.
5721 (A) You've accidentally run your script through B<csh> instead of Perl.
5722 Check the #! line, or manually feed your script into Perl yourself.
5726 (A) You've accidentally run your script through B<csh> instead of Perl.
5727 Check the #! line, or manually feed your script into Perl yourself.
5729 =item Trailing \ in regex m/%s/
5731 (F) The regular expression ends with an unbackslashed backslash.
5732 Backslash it. See L<perlre>.
5734 =item Transliteration pattern not terminated
5736 (F) The lexer couldn't find the interior delimiter of a tr/// or tr[][]
5737 or y/// or y[][] construct. Missing the leading C<$> from variables
5738 C<$tr> or C<$y> may cause this error.
5740 =item Transliteration replacement not terminated
5742 (F) The lexer couldn't find the final delimiter of a tr///, tr[][],
5743 y/// or y[][] construct.
5745 =item '%s' trapped by operation mask
5747 (F) You tried to use an operator from a Safe compartment in which it's
5748 disallowed. See L<Safe>.
5750 =item truncate not implemented
5752 (F) Your machine doesn't implement a file truncation mechanism that
5753 Configure knows about.
5755 =item Type of arg %d to &CORE::%s must be %s
5757 (F) The subroutine in question in the CORE package requires its argument
5758 to be a hard reference to data of the specified type. Overloading is
5759 ignored, so a reference to an object that is not the specified type, but
5760 nonetheless has overloading to handle it, will still not be accepted.
5762 =item Type of arg %d to %s must be %s (not %s)
5764 (F) This function requires the argument in that position to be of a
5765 certain type. Arrays must be @NAME or C<@{EXPR}>. Hashes must be
5766 %NAME or C<%{EXPR}>. No implicit dereferencing is allowed--use the
5767 {EXPR} forms as an explicit dereference. See L<perlref>.
5769 =item Type of argument to %s must be unblessed hashref or arrayref
5771 (F) You called C<keys>, C<values> or C<each> with a scalar argument that
5772 was not a reference to an unblessed hash or array.
5774 =item umask not implemented
5776 (F) Your machine doesn't implement the umask function and you tried to
5777 use it to restrict permissions for yourself (EXPR & 0700).
5779 =item Unbalanced context: %d more PUSHes than POPs
5781 (S internal) The exit code detected an internal inconsistency in how
5782 many execution contexts were entered and left.
5784 =item Unbalanced saves: %d more saves than restores
5786 (S internal) The exit code detected an internal inconsistency in how
5787 many values were temporarily localized.
5789 =item Unbalanced scopes: %d more ENTERs than LEAVEs
5791 (S internal) The exit code detected an internal inconsistency in how
5792 many blocks were entered and left.
5794 =item Unbalanced string table refcount: (%d) for "%s"
5796 (S internal) On exit, Perl found some strings remaining in the shared
5797 string table used for copy on write and for hash keys. The entries
5798 should have been freed, so this indicates a bug somewhere.
5800 =item Unbalanced tmps: %d more allocs than frees
5802 (S internal) The exit code detected an internal inconsistency in how
5803 many mortal scalars were allocated and freed.
5805 =item Undefined format "%s" called
5807 (F) The format indicated doesn't seem to exist. Perhaps it's really in
5808 another package? See L<perlform>.
5810 =item Undefined sort subroutine "%s" called
5812 (F) The sort comparison routine specified doesn't seem to exist.
5813 Perhaps it's in a different package? See L<perlfunc/sort>.
5815 =item Undefined subroutine &%s called
5817 (F) The subroutine indicated hasn't been defined, or if it was, it has
5818 since been undefined.
5820 =item Undefined subroutine called
5822 (F) The anonymous subroutine you're trying to call hasn't been defined,
5823 or if it was, it has since been undefined.
5825 =item Undefined subroutine in sort
5827 (F) The sort comparison routine specified is declared but doesn't seem
5828 to have been defined yet. See L<perlfunc/sort>.
5830 =item Undefined top format "%s" called
5832 (F) The format indicated doesn't seem to exist. Perhaps it's really in
5833 another package? See L<perlform>.
5835 =item Undefined value assigned to typeglob
5837 (W misc) An undefined value was assigned to a typeglob, a la
5838 C<*foo = undef>. This does nothing. It's possible that you really mean
5841 =item %s: Undefined variable
5843 (A) You've accidentally run your script through B<csh> instead of Perl.
5844 Check the #! line, or manually feed your script into Perl yourself.
5846 =item Unescaped left brace in regex is deprecated, passed through in regex;
5847 marked by <-- HERE in m/%s/
5849 (D deprecated, regexp) You used a literal C<"{"> character in a regular
5850 expression pattern. You should change to use C<"\{"> instead, because a
5851 future version of Perl (tentatively v5.26) will consider this to be a
5852 syntax error. If the pattern delimiters are also braces, any matching
5853 right brace (C<"}">) should also be escaped to avoid confusing the parser,
5858 =item unexec of %s into %s failed!
5860 (F) The unexec() routine failed for some reason. See your local FSF
5861 representative, who probably put it there in the first place.
5863 =item Unexpected binary operator '%c' with no preceding operand in regex;
5864 marked by S<<-- HERE> in m/%s/
5866 (F) You had something like this:
5870 where the C<"|"> is a binary operator with an operand on the right, but
5871 no operand on the left.
5873 =item Unexpected character in regex; marked by S<<-- HERE> in m/%s/
5875 (F) You had something like this:
5879 Within C<(?[ ])>, no literal characters are allowed unless they are
5880 within an inner pair of square brackets, like
5884 Another possibility is that you forgot a backslash. Perl isn't smart
5885 enough to figure out what you really meant.
5887 =item Unexpected constant lvalue entersub entry via type/targ %d:%d
5889 (P) When compiling a subroutine call in lvalue context, Perl failed an
5890 internal consistency check. It encountered a malformed op tree.
5892 =item Unexpected exit %u
5894 (S) exit() was called or the script otherwise finished gracefully when
5895 C<PERL_EXIT_WARN> was set in C<PL_exit_flags>.
5897 =item Unexpected exit failure %d
5899 (S) An uncaught die() was called when C<PERL_EXIT_WARN> was set in
5902 =item Unexpected ')' in regex; marked by S<<-- HERE> in m/%s/
5904 (F) You had something like this:
5906 (?[ ( \p{Digit} + ) ])
5908 The C<")"> is out-of-place. Something apparently was supposed to
5909 be combined with the digits, or the C<"+"> shouldn't be there, or
5910 something like that. Perl can't figure out what was intended.
5912 =item Unexpected '(' with no preceding operator in regex; marked by
5913 S<<-- HERE> in m/%s/
5915 (F) You had something like this:
5917 (?[ \p{Digit} ( \p{Lao} + \p{Thai} ) ])
5919 There should be an operator before the C<"(">, as there's
5920 no indication as to how the digits are to be combined
5921 with the characters in the Lao and Thai scripts.
5923 =item Unicode non-character U+%X is illegal for open interchange
5925 (S nonchar) Certain codepoints, such as U+FFFE and U+FFFF, are
5926 defined by the Unicode standard to be non-characters. Those
5927 are legal codepoints, but are reserved for internal use; so,
5928 applications shouldn't attempt to exchange them. An application
5929 may not be expecting any of these characters at all, and receiving
5930 them may lead to bugs. If you know what you are doing you can
5931 turn off this warning by C<no warnings 'nonchar';>.
5933 This is not really a "severe" error, but it is supposed to be
5934 raised by default even if warnings are not enabled, and currently
5935 the only way to do that in Perl is to mark it as serious.
5937 =item Unicode surrogate U+%X is illegal in UTF-8
5939 (S surrogate) You had a UTF-16 surrogate in a context where they are
5940 not considered acceptable. These code points, between U+D800 and
5941 U+DFFF (inclusive), are used by Unicode only for UTF-16. However, Perl
5942 internally allows all unsigned integer code points (up to the size limit
5943 available on your platform), including surrogates. But these can cause
5944 problems when being input or output, which is likely where this message
5945 came from. If you really really know what you are doing you can turn
5946 off this warning by C<no warnings 'surrogate';>.
5948 =item Unknown charname '%s'
5950 (F) The name you used inside C<\N{}> is unknown to Perl. Check the
5951 spelling. You can say C<use charnames ":loose"> to not have to be
5952 so precise about spaces, hyphens, and capitalization on standard Unicode
5953 names. (Any custom aliases that have been created must be specified
5954 exactly, regardless of whether C<:loose> is used or not.) This error may
5955 also happen if the C<\N{}> is not in the scope of the corresponding
5956 C<S<use charnames>>.
5960 (P) Perl was about to print an error message in C<$@>, but the C<$@> variable
5961 did not exist, even after an attempt to create it.
5963 =item Unknown open() mode '%s'
5965 (F) The second argument of 3-argument open() is not among the list
5966 of valid modes: C<< < >>, C<< > >>, C<<< >> >>>, C<< +< >>,
5967 C<< +> >>, C<<< +>> >>>, C<-|>, C<|->, C<< <& >>, C<< >& >>.
5969 =item Unknown PerlIO layer "%s"
5971 (W layer) An attempt was made to push an unknown layer onto the Perl I/O
5972 system. (Layers take care of transforming data between external and
5973 internal representations.) Note that some layers, such as C<mmap>,
5974 are not supported in all environments. If your program didn't
5975 explicitly request the failing operation, it may be the result of the
5976 value of the environment variable PERLIO.
5978 =item Unknown process %x sent message to prime_env_iter: %s
5980 (P) An error peculiar to VMS. Perl was reading values for %ENV before
5981 iterating over it, and someone else stuck a message in the stream of
5982 data Perl expected. Someone's very confused, or perhaps trying to
5983 subvert Perl's population of %ENV for nefarious purposes.
5985 =item Unknown regex modifier "%s"
5987 (F) Alphanumerics immediately following the closing delimiter
5988 of a regular expression pattern are interpreted by Perl as modifier
5989 flags for the regex. One of the ones you specified is invalid. One way
5990 this can happen is if you didn't put in white space between the end of
5991 the regex and a following alphanumeric operator:
5993 if ($a =~ /foo/and $bar == 3) { ... }
5995 The C<"a"> is a valid modifier flag, but the C<"n"> is not, and raises
5996 this error. Likely what was meant instead was:
5998 if ($a =~ /foo/ and $bar == 3) { ... }
6000 =item Unknown "re" subpragma '%s' (known ones are: %s)
6002 (W) You tried to use an unknown subpragma of the "re" pragma.
6004 =item Unknown switch condition (?(...)) in regex; marked by S<<-- HERE> in
6007 (F) The condition part of a (?(condition)if-clause|else-clause) construct
6008 is not known. The condition must be one of the following:
6010 (1) (2) ... true if 1st, 2nd, etc., capture matched
6011 (<NAME>) ('NAME') true if named capture matched
6012 (?=...) (?<=...) true if subpattern matches
6013 (?!...) (?<!...) true if subpattern fails to match
6014 (?{ CODE }) true if code returns a true value
6015 (R) true if evaluating inside recursion
6016 (R1) (R2) ... true if directly inside capture group 1, 2, etc.
6017 (R&NAME) true if directly inside named capture
6018 (DEFINE) always false; for defining named subpatterns
6020 The <-- HERE shows whereabouts in the regular expression the problem was
6021 discovered. See L<perlre>.
6023 =item Unknown Unicode option letter '%c'
6025 (F) You specified an unknown Unicode option. See L<perlrun> documentation
6026 of the C<-C> switch for the list of known options.
6028 =item Unknown Unicode option value %d
6030 (F) You specified an unknown Unicode option. See L<perlrun> documentation
6031 of the C<-C> switch for the list of known options.
6033 =item Unknown verb pattern '%s' in regex; marked by S<<-- HERE> in m/%s/
6035 (F) You either made a typo or have incorrectly put a C<*> quantifier
6036 after an open brace in your pattern. Check the pattern and review
6037 L<perlre> for details on legal verb patterns.
6039 =item Unknown warnings category '%s'
6041 (F) An error issued by the C<warnings> pragma. You specified a warnings
6042 category that is unknown to perl at this point.
6044 Note that if you want to enable a warnings category registered by a
6045 module (e.g. C<use warnings 'File::Find'>), you must have loaded this
6048 =item Unmatched '[' in POSIX class in regex; marked by S<<-- HERE> in m/%s/
6050 (F) You had something like this:
6054 That should be written:
6058 =item Unmatched '%c' in POSIX class in regex; marked by S<<-- HERE> in
6061 (F) You had something like this:
6065 There should be a second C<":">, like this:
6069 =item Unmatched [ in regex; marked by S<<-- HERE> in m/%s/
6071 (F) The brackets around a character class must match. If you wish to
6072 include a closing bracket in a character class, backslash it or put it
6073 first. The S<<-- HERE> shows whereabouts in the regular expression the
6074 problem was discovered. See L<perlre>.
6076 =item Unmatched ( in regex; marked by S<<-- HERE> in m/%s/
6078 =item Unmatched ) in regex; marked by S<<-- HERE> in m/%s/
6080 (F) Unbackslashed parentheses must always be balanced in regular
6081 expressions. If you're a vi user, the % key is valuable for finding
6082 the matching parenthesis. The S<<-- HERE> shows whereabouts in the
6083 regular expression the problem was discovered. See L<perlre>.
6085 =item Unmatched right %s bracket
6087 (F) The lexer counted more closing curly or square brackets than opening
6088 ones, so you're probably missing a matching opening bracket. As a
6089 general rule, you'll find the missing one (so to speak) near the place
6090 you were last editing.
6092 =item Unquoted string "%s" may clash with future reserved word
6094 (W reserved) You used a bareword that might someday be claimed as a
6095 reserved word. It's best to put such a word in quotes, or capitalize it
6096 somehow, or insert an underbar into it. You might also declare it as a
6099 =item Unrecognized character %s; marked by S<<-- HERE> after %s near column
6102 (F) The Perl parser has no idea what to do with the specified character
6103 in your Perl script (or eval) near the specified column. Perhaps you
6104 tried to run a compressed script, a binary program, or a directory as
6107 =item Unrecognized escape \%c in character class in regex; marked by
6108 S<<-- HERE> in m/%s/
6110 (F) You used a backslash-character combination which is not
6111 recognized by Perl inside character classes. This is a fatal
6112 error when the character class is used within C<(?[ ])>.
6114 =item Unrecognized escape \%c in character class passed through in regex;
6115 marked by S<<-- HERE> in m/%s/
6117 (W regexp) You used a backslash-character combination which is not
6118 recognized by Perl inside character classes. The character was
6119 understood literally, but this may change in a future version of Perl.
6120 The S<<-- HERE> shows whereabouts in the regular expression the
6121 escape was discovered.
6123 =item Unrecognized escape \%c passed through
6125 (W misc) You used a backslash-character combination which is not
6126 recognized by Perl. The character was understood literally, but this may
6127 change in a future version of Perl.
6129 =item Unrecognized escape \%s passed through in regex; marked by
6130 S<<-- HERE> in m/%s/
6132 (W regexp) You used a backslash-character combination which is not
6133 recognized by Perl. The character(s) were understood literally, but
6134 this may change in a future version of Perl. The S<<-- HERE> shows
6135 whereabouts in the regular expression the escape was discovered.
6137 =item Unrecognized signal name "%s"
6139 (F) You specified a signal name to the kill() function that was not
6140 recognized. Say C<kill -l> in your shell to see the valid signal names
6143 =item Unrecognized switch: -%s (-h will show valid options)
6145 (F) You specified an illegal option to Perl. Don't do that. (If you
6146 think you didn't do that, check the #! line to see if it's supplying the
6147 bad switch on your behalf.)
6149 =item unshift on reference is experimental
6151 (S experimental::autoderef) C<unshift> with a scalar argument
6152 is experimental and may change or be removed in a future
6153 Perl version. If you want to take the risk of using this
6154 feature, simply disable this warning:
6156 no warnings "experimental::autoderef";
6158 =item Unsuccessful %s on filename containing newline
6160 (W newline) A file operation was attempted on a filename, and that
6161 operation failed, PROBABLY because the filename contained a newline,
6162 PROBABLY because you forgot to chomp() it off. See L<perlfunc/chomp>.
6164 =item Unsupported directory function "%s" called
6166 (F) Your machine doesn't support opendir() and readdir().
6168 =item Unsupported function %s
6170 (F) This machine doesn't implement the indicated function, apparently.
6171 At least, Configure doesn't think so.
6173 =item Unsupported function fork
6175 (F) Your version of executable does not support forking.
6177 Note that under some systems, like OS/2, there may be different flavors
6178 of Perl executables, some of which may support fork, some not. Try
6179 changing the name you call Perl by to C<perl_>, C<perl__>, and so on.
6181 =item Unsupported script encoding %s
6183 (F) Your program file begins with a Unicode Byte Order Mark (BOM) which
6184 declares it to be in a Unicode encoding that Perl cannot read.
6186 =item Unsupported socket function "%s" called
6188 (F) Your machine doesn't support the Berkeley socket mechanism, or at
6189 least that's what Configure thought.
6191 =item Unterminated attribute list
6193 (F) The lexer found something other than a simple identifier at the
6194 start of an attribute, and it wasn't a semicolon or the start of a
6195 block. Perhaps you terminated the parameter list of the previous
6196 attribute too soon. See L<attributes>.
6198 =item Unterminated attribute parameter in attribute list
6200 (F) The lexer saw an opening (left) parenthesis character while parsing
6201 an attribute list, but the matching closing (right) parenthesis
6202 character was not found. You may need to add (or remove) a backslash
6203 character to get your parentheses to balance. See L<attributes>.
6205 =item Unterminated compressed integer
6207 (F) An argument to unpack("w",...) was incompatible with the BER
6208 compressed integer format and could not be converted to an integer.
6209 See L<perlfunc/pack>.
6211 =item Unterminated delimiter for here document
6213 (F) This message occurs when a here document label has an initial
6214 quotation mark but the final quotation mark is missing. Perhaps
6223 =item Unterminated \g... pattern in regex; marked by S<<-- HERE> in m/%s/
6225 =item Unterminated \g{...} pattern in regex; marked by S<<-- HERE> in m/%s/
6227 (F) In a regular expression, you had a C<\g> that wasn't followed by a
6228 proper group reference. In the case of C<\g{>, the closing brace is
6229 missing; otherwise the C<\g> must be followed by an integer. Fix the
6232 =item Unterminated <> operator
6234 (F) The lexer saw a left angle bracket in a place where it was expecting
6235 a term, so it's looking for the corresponding right angle bracket, and
6236 not finding it. Chances are you left some needed parentheses out
6237 earlier in the line, and you really meant a "less than".
6239 =item Unterminated verb pattern argument in regex; marked by S<<-- HERE> in
6242 (F) You used a pattern of the form C<(*VERB:ARG)> but did not terminate
6243 the pattern with a C<)>. Fix the pattern and retry.
6245 =item Unterminated verb pattern in regex; marked by S<<-- HERE> in m/%s/
6247 (F) You used a pattern of the form C<(*VERB)> but did not terminate
6248 the pattern with a C<)>. Fix the pattern and retry.
6250 =item untie attempted while %d inner references still exist
6252 (W untie) A copy of the object returned from C<tie> (or C<tied>) was
6253 still valid when C<untie> was called.
6255 =item Usage: POSIX::%s(%s)
6257 (F) You called a POSIX function with incorrect arguments.
6258 See L<POSIX/FUNCTIONS> for more information.
6260 =item Usage: Win32::%s(%s)
6262 (F) You called a Win32 function with incorrect arguments.
6263 See L<Win32> for more information.
6265 =item $[ used in %s (did you mean $] ?)
6267 (W syntax) You used C<$[> in a comparison, such as:
6273 You probably meant to use C<$]> instead. C<$[> is the base for indexing
6274 arrays. C<$]> is the Perl version number in decimal.
6276 =item Use "%s" instead of "%s"
6278 (F) The second listed construct is no longer legal. Use the first one
6281 =item Useless assignment to a temporary
6283 (W misc) You assigned to an lvalue subroutine, but what
6284 the subroutine returned was a temporary scalar about to
6285 be discarded, so the assignment had no effect.
6287 =item Useless (?-%s) - don't use /%s modifier in regex; marked by
6288 S<<-- HERE> in m/%s/
6290 (W regexp) You have used an internal modifier such as (?-o) that has no
6291 meaning unless removed from the entire regexp:
6293 if ($string =~ /(?-o)$pattern/o) { ... }
6297 if ($string =~ /$pattern/) { ... }
6299 The <-- HERE shows whereabouts in the regular expression the problem was
6300 discovered. See L<perlre>.
6302 =item Useless localization of %s
6304 (W syntax) The localization of lvalues such as C<local($x=10)> is legal,
6305 but in fact the local() currently has no effect. This may change at
6306 some point in the future, but in the meantime such code is discouraged.
6308 =item Useless (?%s) - use /%s modifier in regex; marked by S<<-- HERE> in
6311 (W regexp) You have used an internal modifier such as (?o) that has no
6312 meaning unless applied to the entire regexp:
6314 if ($string =~ /(?o)$pattern/) { ... }
6318 if ($string =~ /$pattern/o) { ... }
6320 The <-- HERE shows whereabouts in the regular expression the problem was
6321 discovered. See L<perlre>.
6323 =item Useless use of /d modifier in transliteration operator
6325 (W misc) You have used the /d modifier where the searchlist has the
6326 same length as the replacelist. See L<perlop> for more information
6327 about the /d modifier.
6329 =item Useless use of \E
6331 (W misc) You have a \E in a double-quotish string without a C<\U>,
6332 C<\L> or C<\Q> preceding it.
6334 =item Useless use of greediness modifier '%c' in regex; marked by S<<-- HERE> in m/%s/
6336 (W regexp) You specified something like these:
6341 The C<"?"> and C<"+"> don't have any effect, as they modify whether to
6342 match more or fewer when there is a choice, and by specifying to match
6343 exactly a given numer, there is no room left for a choice.
6345 =item Useless use of %s in void context
6347 (W void) You did something without a side effect in a context that does
6348 nothing with the return value, such as a statement that doesn't return a
6349 value from a block, or the left side of a scalar comma operator. Very
6350 often this points not to stupidity on your part, but a failure of Perl
6351 to parse your program the way you thought it would. For example, you'd
6352 get this if you mixed up your C precedence with Python precedence and
6357 when you meant to say
6359 ($one, $two) = (1, 2);
6361 Another common error is to use ordinary parentheses to construct a list
6362 reference when you should be using square or curly brackets, for
6367 when you should have said
6371 The square brackets explicitly turn a list value into a scalar value,
6372 while parentheses do not. So when a parenthesized list is evaluated in
6373 a scalar context, the comma is treated like C's comma operator, which
6374 throws away the left argument, which is not what you want. See
6375 L<perlref> for more on this.
6377 This warning will not be issued for numerical constants equal to 0 or 1
6378 since they are often used in statements like
6380 1 while sub_with_side_effects();
6382 String constants that would normally evaluate to 0 or 1 are warned
6385 =item Useless use of (?-p) in regex; marked by S<<-- HERE> in m/%s/
6387 (W regexp) The C<p> modifier cannot be turned off once set. Trying to do
6390 =item Useless use of "re" pragma
6392 (W) You did C<use re;> without any arguments. That isn't very useful.
6394 =item Useless use of sort in scalar context
6396 (W void) You used sort in scalar context, as in :
6400 This is not very useful, and perl currently optimizes this away.
6402 =item Useless use of %s with no values
6404 (W syntax) You used the push() or unshift() function with no arguments
6405 apart from the array, like C<push(@x)> or C<unshift(@foo)>. That won't
6406 usually have any effect on the array, so is completely useless. It's
6407 possible in principle that push(@tied_array) could have some effect
6408 if the array is tied to a class which implements a PUSH method. If so,
6409 you can write it as C<push(@tied_array,())> to avoid this warning.
6411 =item "use" not allowed in expression
6413 (F) The "use" keyword is recognized and executed at compile time, and
6414 returns no useful value. See L<perlmod>.
6416 =item Use of assignment to $[ is deprecated
6418 (D deprecated) The C<$[> variable (index of the first element in an array)
6419 is deprecated. See L<perlvar/"$[">.
6421 =item Use of bare << to mean <<"" is deprecated
6423 (D deprecated) You are now encouraged to use the explicitly quoted
6424 form if you wish to use an empty line as the terminator of the
6427 =item Use of chdir('') or chdir(undef) as chdir() deprecated
6429 (D deprecated) chdir() with no arguments is documented to change to
6430 $ENV{HOME} or $ENV{LOGDIR}. chdir(undef) and chdir('') share this
6431 behavior, but that has been deprecated. In future versions they
6434 Be careful to check that what you pass to chdir() is defined and not
6435 blank, else you might find yourself in your home directory.
6437 =item Use of /c modifier is meaningless in s///
6439 (W regexp) You used the /c modifier in a substitution. The /c
6440 modifier is not presently meaningful in substitutions.
6442 =item Use of /c modifier is meaningless without /g
6444 (W regexp) You used the /c modifier with a regex operand, but didn't
6445 use the /g modifier. Currently, /c is meaningful only when /g is
6446 used. (This may change in the future.)
6448 =item Use of comma-less variable list is deprecated
6450 (D deprecated) The values you give to a format should be
6451 separated by commas, not just aligned on a line.
6453 =item Use of each() on hash after insertion without resetting hash iterator results in undefined behavior
6455 (S internal) The behavior of C<each()> after insertion is undefined;
6456 it may skip items, or visit items more than once. Consider using
6457 C<keys()> instead of C<each()>.
6459 =item Use of := for an empty attribute list is not allowed
6461 (F) The construction C<my $x := 42> used to parse as equivalent to
6462 C<my $x : = 42> (applying an empty attribute list to C<$x>).
6463 This construct was deprecated in 5.12.0, and has now been made a syntax
6464 error, so C<:=> can be reclaimed as a new operator in the future.
6466 If you need an empty attribute list, for example in a code generator, add
6467 a space before the C<=>.
6469 =item Use of freed value in iteration
6471 (F) Perhaps you modified the iterated array within the loop?
6472 This error is typically caused by code like the following:
6475 @a = () for (1,2,@a);
6477 You are not supposed to modify arrays while they are being iterated over.
6478 For speed and efficiency reasons, Perl internally does not do full
6479 reference-counting of iterated items, hence deleting such an item in the
6480 middle of an iteration causes Perl to see a freed value.
6482 =item Use of *glob{FILEHANDLE} is deprecated
6484 (D deprecated) You are now encouraged to use the shorter *glob{IO} form
6485 to access the filehandle slot within a typeglob.
6487 =item Use of /g modifier is meaningless in split
6489 (W regexp) You used the /g modifier on the pattern for a C<split>
6490 operator. Since C<split> always tries to match the pattern
6491 repeatedly, the C</g> has no effect.
6493 =item Use of "goto" to jump into a construct is deprecated
6495 (D deprecated) Using C<goto> to jump from an outer scope into an inner
6496 scope is deprecated and should be avoided.
6498 =item Use of inherited AUTOLOAD for non-method %s() is deprecated
6500 (D deprecated) As an (ahem) accidental feature, C<AUTOLOAD>
6501 subroutines are looked up as methods (using the C<@ISA> hierarchy)
6502 even when the subroutines to be autoloaded were called as plain
6503 functions (e.g. C<Foo::bar()>), not as methods (e.g. C<< Foo->bar() >> or
6504 C<< $obj->bar() >>).
6506 This bug will be rectified in future by using method lookup only for
6507 methods' C<AUTOLOAD>s. However, there is a significant base of existing
6508 code that may be using the old behavior. So, as an interim step, Perl
6509 currently issues an optional warning when non-methods use inherited
6512 The simple rule is: Inheritance will not work when autoloading
6513 non-methods. The simple fix for old code is: In any module that used
6514 to depend on inheriting C<AUTOLOAD> for non-methods from a base class
6515 named C<BaseClass>, execute C<*AUTOLOAD = \&BaseClass::AUTOLOAD> during
6518 In code that currently says C<use AutoLoader; @ISA = qw(AutoLoader);>
6519 you should remove AutoLoader from @ISA and change C<use AutoLoader;> to
6520 C<use AutoLoader 'AUTOLOAD';>.
6522 =item Use of %s in printf format not supported
6524 (F) You attempted to use a feature of printf that is accessible from
6525 only C. This usually means there's a better way to do it in Perl.
6527 =item Use of %s is deprecated
6529 (D deprecated) The construct indicated is no longer recommended for use,
6530 generally because there's a better way to do it, and also because the
6531 old way has bad side effects.
6533 =item Use of literal control characters in variable names is deprecated
6535 (D deprecated) Using literal control characters in the source to refer
6536 to the ^FOO variables, like C<$^X> and C<${^GLOBAL_PHASE}> is now
6537 deprecated. This only affects code like C<$\cT>, where \cT is a control in
6538 the source code: C<${"\cT"}> and C<$^T> remain valid.
6540 =item Use of -l on filehandle%s
6542 (W io) A filehandle represents an opened file, and when you opened the file
6543 it already went past any symlink you are presumably trying to look for.
6544 The operation returned C<undef>. Use a filename instead.
6546 =item Use of my $_ is experimental
6548 (S experimental::lexical_topic) Lexical $_ is an experimental feature and
6549 its behavior may change or even be removed in any future release of perl.
6550 See the explanation under L<perlvar/$_>.
6552 =item Use of %s on a handle without * is deprecated
6554 (D deprecated) You used C<tie>, C<tied> or C<untie> on a scalar but that scalar
6555 happens to hold a typeglob, which means its filehandle will be tied. If
6556 you mean to tie a handle, use an explicit * as in C<tie *$handle>.
6558 This was a long-standing bug that was removed in Perl 5.16, as there was
6559 no way to tie the scalar itself when it held a typeglob, and no way to
6560 untie a scalar that had had a typeglob assigned to it. If you see this
6561 message, you must be using an older version.
6563 =item Use of reference "%s" as array index
6565 (W misc) You tried to use a reference as an array index; this probably
6566 isn't what you mean, because references in numerical context tend
6567 to be huge numbers, and so usually indicates programmer error.
6569 If you really do mean it, explicitly numify your reference, like so:
6570 C<$array[0+$ref]>. This warning is not given for overloaded objects,
6571 however, because you can overload the numification and stringification
6572 operators and then you presumably know what you are doing.
6574 =item Use of state $_ is experimental
6576 (S experimental::lexical_topic) Lexical $_ is an experimental feature and
6577 its behavior may change or even be removed in any future release of perl.
6578 See the explanation under L<perlvar/$_>.
6580 =item Use of tainted arguments in %s is deprecated
6582 (W taint, deprecated) You have supplied C<system()> or C<exec()> with multiple
6583 arguments and at least one of them is tainted. This used to be allowed
6584 but will become a fatal error in a future version of perl. Untaint your
6585 arguments. See L<perlsec>.
6587 =item Use of uninitialized value%s
6589 (W uninitialized) An undefined value was used as if it were already
6590 defined. It was interpreted as a "" or a 0, but maybe it was a mistake.
6591 To suppress this warning assign a defined value to your variables.
6593 To help you figure out what was undefined, perl will try to tell you
6594 the name of the variable (if any) that was undefined. In some cases
6595 it cannot do this, so it also tells you what operation you used the
6596 undefined value in. Note, however, that perl optimizes your program
6597 and the operation displayed in the warning may not necessarily appear
6598 literally in your program. For example, C<"that $foo"> is usually
6599 optimized into C<"that " . $foo>, and the warning will refer to the
6600 C<concatenation (.)> operator, even though there is no C<.> in
6603 =item Use \x{...} for more than two hex characters in regex; marked by
6604 S<<-- HERE> in m/%s/
6606 (F) In a regular expression, you said something like
6610 Perl isn't sure if you meant this
6614 or if you meant this
6616 (?[ [ \x{BE} E F ] ])
6618 You need to add either braces or blanks to disambiguate.
6620 =item Using just the first character returned by \N{} in character class in
6621 regex; marked by S<<-- HERE> in m/%s/
6623 (W regexp) Named Unicode character escapes C<(\N{...})> may return
6624 a multi-character sequence. Even though a character class is
6625 supposed to match just one character of input, perl will match
6626 the whole thing correctly, except when the class is inverted
6627 (C<[^...]>), or the escape is the beginning or final end point of
6628 a range. For these, what should happen isn't clear at all. In
6629 these circumstances, Perl discards all but the first character
6630 of the returned sequence, which is not likely what you want.
6632 =item Using !~ with %s doesn't make sense
6634 (F) Using the C<!~> operator with C<s///r>, C<tr///r> or C<y///r> is
6635 currently reserved for future use, as the exact behaviour has not
6636 been decided. (Simply returning the boolean opposite of the
6637 modified string is usually not particularly useful.)
6639 =item UTF-16 surrogate U+%X
6641 (S surrogate) You had a UTF-16 surrogate in a context where they are
6642 not considered acceptable. These code points, between U+D800 and
6643 U+DFFF (inclusive), are used by Unicode only for UTF-16. However, Perl
6644 internally allows all unsigned integer code points (up to the size limit
6645 available on your platform), including surrogates. But these can cause
6646 problems when being input or output, which is likely where this message
6647 came from. If you really really know what you are doing you can turn
6648 off this warning by C<no warnings 'surrogate';>.
6650 =item Value of %s can be "0"; test with defined()
6652 (W misc) In a conditional expression, you used <HANDLE>, <*> (glob),
6653 C<each()>, or C<readdir()> as a boolean value. Each of these constructs
6654 can return a value of "0"; that would make the conditional expression
6655 false, which is probably not what you intended. When using these
6656 constructs in conditional expressions, test their values with the
6657 C<defined> operator.
6659 =item Value of CLI symbol "%s" too long
6661 (W misc) A warning peculiar to VMS. Perl tried to read the value of an
6662 %ENV element from a CLI symbol table, and found a resultant string
6663 longer than 1024 characters. The return value has been truncated to
6666 =item values on reference is experimental
6668 (S experimental::autoderef) C<values> with a scalar argument
6669 is experimental and may change or be removed in a future
6670 Perl version. If you want to take the risk of using this
6671 feature, simply disable this warning:
6673 no warnings "experimental::autoderef";
6675 =item Variable "%s" is not available
6677 (W closure) During compilation, an inner named subroutine or eval is
6678 attempting to capture an outer lexical that is not currently available.
6679 This can happen for one of two reasons. First, the outer lexical may be
6680 declared in an outer anonymous subroutine that has not yet been created.
6681 (Remember that named subs are created at compile time, while anonymous
6682 subs are created at run-time.) For example,
6684 sub { my $a; sub f { $a } }
6686 At the time that f is created, it can't capture the current value of $a,
6687 since the anonymous subroutine hasn't been created yet. Conversely,
6688 the following won't give a warning since the anonymous subroutine has by
6689 now been created and is live:
6691 sub { my $a; eval 'sub f { $a }' }->();
6693 The second situation is caused by an eval accessing a variable that has
6694 gone out of scope, for example,
6702 Here, when the '$a' in the eval is being compiled, f() is not currently
6703 being executed, so its $a is not available for capture.
6705 =item Variable "%s" is not imported%s
6707 (S misc) With "use strict" in effect, you referred to a global variable
6708 that you apparently thought was imported from another module, because
6709 something else of the same name (usually a subroutine) is exported by
6710 that module. It usually means you put the wrong funny character on the
6711 front of your variable.
6713 =item Variable length lookbehind not implemented in regex m/%s/
6715 (F) Lookbehind is allowed only for subexpressions whose length is fixed and
6716 known at compile time. For positive lookbehind, you can use the C<\K>
6717 regex construct as a way to get the equivalent functionality. See
6718 L<perlre/(?<=pattern) \K>.
6720 There are non-obvious Unicode rules under C</i> that can match variably,
6721 but which you might not think could. For example, the substring C<"ss">
6722 can match the single character LATIN SMALL LETTER SHARP S. There are
6723 other sequences of ASCII characters that can match single ligature
6724 characters, such as LATIN SMALL LIGATURE FFI matching C<qr/ffi/i>.
6725 Starting in Perl v5.16, if you only care about ASCII matches, adding the
6726 C</aa> modifier to the regex will exclude all these non-obvious matches,
6727 thus getting rid of this message. You can also say C<S<use re qw(/aa)>>
6728 to apply C</aa> to all regular expressions compiled within its scope.
6731 =item "%s" variable %s masks earlier declaration in same %s
6733 (W misc) A "my", "our" or "state" variable has been redeclared in the
6734 current scope or statement, effectively eliminating all access to the
6735 previous instance. This is almost always a typographical error. Note
6736 that the earlier variable will still exist until the end of the scope
6737 or until all closure references to it are destroyed.
6739 =item Variable syntax
6741 (A) You've accidentally run your script through B<csh> instead
6742 of Perl. Check the #! line, or manually feed your script into
6745 =item Variable "%s" will not stay shared
6747 (W closure) An inner (nested) I<named> subroutine is referencing a
6748 lexical variable defined in an outer named subroutine.
6750 When the inner subroutine is called, it will see the value of
6751 the outer subroutine's variable as it was before and during the *first*
6752 call to the outer subroutine; in this case, after the first call to the
6753 outer subroutine is complete, the inner and outer subroutines will no
6754 longer share a common value for the variable. In other words, the
6755 variable will no longer be shared.
6757 This problem can usually be solved by making the inner subroutine
6758 anonymous, using the C<sub {}> syntax. When inner anonymous subs that
6759 reference variables in outer subroutines are created, they
6760 are automatically rebound to the current values of such variables.
6762 =item vector argument not supported with alpha versions
6764 (S printf) The %vd (s)printf format does not support version objects
6767 =item Verb pattern '%s' has a mandatory argument in regex; marked by
6768 S<<-- HERE> in m/%s/
6770 (F) You used a verb pattern that requires an argument. Supply an
6771 argument or check that you are using the right verb.
6773 =item Verb pattern '%s' may not have an argument in regex; marked by
6774 S<<-- HERE> in m/%s/
6776 (F) You used a verb pattern that is not allowed an argument. Remove the
6777 argument or check that you are using the right verb.
6779 =item Version number must be a constant number
6781 (P) The attempt to translate a C<use Module n.n LIST> statement into
6782 its equivalent C<BEGIN> block found an internal inconsistency with
6785 =item Version string '%s' contains invalid data; ignoring: '%s'
6787 (W misc) The version string contains invalid characters at the end, which
6790 =item Warning: something's wrong
6792 (W) You passed warn() an empty string (the equivalent of C<warn "">) or
6793 you called it with no args and C<$@> was empty.
6795 =item Warning: unable to close filehandle %s properly
6797 (S) The implicit close() done by an open() got an error indication on
6798 the close(). This usually indicates your file system ran out of disk
6801 =item Warning: Use of "%s" without parentheses is ambiguous
6803 (S ambiguous) You wrote a unary operator followed by something that
6804 looks like a binary operator that could also have been interpreted as a
6805 term or unary operator. For instance, if you know that the rand
6806 function has a default argument of 1.0, and you write
6810 you may THINK you wrote the same thing as
6814 but in actual fact, you got
6818 So put in parentheses to say what you really mean.
6820 =item when is experimental
6822 (S experimental::smartmatch) C<when> depends on smartmatch, which is
6823 experimental. Additionally, it has several special cases that may
6824 not be immediately obvious, and their behavior may change or
6825 even be removed in any future release of perl. See the explanation
6826 under L<perlsyn/Experimental Details on given and when>.
6828 =item Wide character in %s
6830 (S utf8) Perl met a wide character (>255) when it wasn't expecting
6831 one. This warning is by default on for I/O (like print). The easiest
6832 way to quiet this warning is simply to add the C<:utf8> layer to the
6833 output, e.g. C<binmode STDOUT, ':utf8'>. Another way to turn off the
6834 warning is to add C<no warnings 'utf8';> but that is often closer to
6835 cheating. In general, you are supposed to explicitly mark the
6836 filehandle with an encoding, see L<open> and L<perlfunc/binmode>.
6838 =item Within []-length '%c' not allowed
6840 (F) The count in the (un)pack template may be replaced by C<[TEMPLATE]>
6841 only if C<TEMPLATE> always matches the same amount of packed bytes that
6842 can be determined from the template alone. This is not possible if
6843 it contains any of the codes @, /, U, u, w or a *-length. Redesign
6846 =item write() on closed filehandle %s
6848 (W closed) The filehandle you're writing to got itself closed sometime
6849 before now. Check your control flow.
6851 =item %s "\x%X" does not map to Unicode
6853 (S utf8) When reading in different encodings, Perl tries to
6854 map everything into Unicode characters. The bytes you read
6855 in are not legal in this encoding. For example
6857 utf8 "\xE4" does not map to Unicode
6859 if you try to read in the a-diaereses Latin-1 as UTF-8.
6861 =item 'X' outside of string
6863 (F) You had a (un)pack template that specified a relative position before
6864 the beginning of the string being (un)packed. See L<perlfunc/pack>.
6866 =item 'x' outside of string in unpack
6868 (F) You had a pack template that specified a relative position after
6869 the end of the string being unpacked. See L<perlfunc/pack>.
6871 =item YOU HAVEN'T DISABLED SET-ID SCRIPTS IN THE KERNEL YET!
6873 (F) And you probably never will, because you probably don't have the
6874 sources to your kernel, and your vendor probably doesn't give a rip
6875 about what you want. Your best bet is to put a setuid C wrapper around
6878 =item You need to quote "%s"
6880 (W syntax) You assigned a bareword as a signal handler name.
6881 Unfortunately, you already have a subroutine of that name declared,
6882 which means that Perl 5 will try to call the subroutine when the
6883 assignment is executed, which is probably not what you want. (If it IS
6884 what you want, put an & in front.)
6886 =item Your random numbers are not that random
6888 (F) When trying to initialize the random seed for hashes, Perl could
6889 not get any randomness out of your system. This usually indicates
6890 Something Very Wrong.
6892 =item Zero length \N{} in regex; marked by S<<-- HERE> in m/%s/
6894 (F) Named Unicode character escapes (C<\N{...}>) may return a zero-length
6895 sequence. Such an escape was used in an extended character class, i.e.
6896 C<(?[...])>, which is not permitted. Check that the correct escape has
6897 been used, and the correct charnames handler is in scope. The S<<-- HERE>
6898 shows whereabouts in the regular expression the problem was discovered.
6904 L<warnings>, L<diagnostics>.