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<$SIG{__WARN__}>
27 to a reference to a routine that will be called on each warning instead
28 of printing it. See L<perlvar>.
30 Severe warnings are always enabled, unless they are explicitly disabled
31 with the C<warnings> pragma or the B<-X> switch.
33 Trappable errors may be trapped using the eval operator. See
34 L<perlfunc/eval>. In almost all cases, warnings may be selectively
35 disabled or promoted to fatal errors using the C<warnings> pragma.
38 The messages are in alphabetical order, without regard to upper or
39 lower-case. Some of these messages are generic. Spots that vary are
40 denoted with a %s or other printf-style escape. These escapes are
41 ignored by the alphabetical order, as are all characters other than
42 letters. To look up your message, just ignore anything that is not a
47 =item accept() on closed socket %s
49 (W closed) You tried to do an accept on a closed socket. Did you forget
50 to check the return value of your socket() call? See
53 =item Allocation too large: %x
55 (X) You can't allocate more than 64K on an MS-DOS machine.
57 =item '%c' allowed only after types %s in %s
59 (F) The modifiers '!', '<' and '>' are allowed in pack() or unpack() only
60 after certain types. See L<perlfunc/pack>.
62 =item Ambiguous call resolved as CORE::%s(), qualify as such or use &
64 (W ambiguous) A subroutine you have declared has the same name as a Perl
65 keyword, and you have used the name without qualification for calling
66 one or the other. Perl decided to call the builtin because the
67 subroutine is not imported.
69 To force interpretation as a subroutine call, either put an ampersand
70 before the subroutine name, or qualify the name with its package.
71 Alternatively, you can import the subroutine (or pretend that it's
72 imported with the C<use subs> pragma).
74 To silently interpret it as the Perl operator, use the C<CORE::> prefix
75 on the operator (e.g. C<CORE::log($x)>) or declare the subroutine
76 to be an object method (see L<perlsub/"Subroutine Attributes"> or
79 =item Ambiguous range in transliteration operator
81 (F) You wrote something like C<tr/a-z-0//> which doesn't mean anything at
82 all. To include a C<-> character in a transliteration, put it either
83 first or last. (In the past, C<tr/a-z-0//> was synonymous with
84 C<tr/a-y//>, which was probably not what you would have expected.)
86 =item Ambiguous use of %s resolved as %s
88 (S ambiguous) You said something that may not be interpreted the way
89 you thought. Normally it's pretty easy to disambiguate it by supplying
90 a missing quote, operator, parenthesis pair or declaration.
92 =item Ambiguous use of %c resolved as operator %c
94 (S ambiguous) C<%>, C<&>, and C<*> are both infix operators (modulus,
95 bitwise and, and multiplication) I<and> initial special characters
96 (denoting hashes, subroutines and typeglobs), and you said something
97 like C<*foo * foo> that might be interpreted as either of them. We
98 assumed you meant the infix operator, but please try to make it more
99 clear -- in the example given, you might write C<*foo * foo()> if you
100 really meant to multiply a glob by the result of calling a function.
102 =item Ambiguous use of %c{%s} resolved to %c%s
104 (W ambiguous) You wrote something like C<@{foo}>, which might be
105 asking for the variable C<@foo>, or it might be calling a function
106 named foo, and dereferencing it as an array reference. If you wanted
107 the variable, you can just write C<@foo>. If you wanted to call the
108 function, write C<@{foo()}> ... or you could just not have a variable
109 and a function with the same name, and save yourself a lot of trouble.
111 =item Ambiguous use of %c{%s[...]} resolved to %c%s[...]
113 =item Ambiguous use of %c{%s{...}} resolved to %c%s{...}
115 (W ambiguous) You wrote something like C<${foo[2]}> (where foo represents
116 the name of a Perl keyword), which might be looking for element number
117 2 of the array named C<@foo>, in which case please write C<$foo[2]>, or you
118 might have meant to pass an anonymous arrayref to the function named
119 foo, and then do a scalar deref on the value it returns. If you meant
120 that, write C<${foo([2])}>.
122 In regular expressions, the C<${foo[2]}> syntax is sometimes necessary
123 to disambiguate between array subscripts and character classes.
124 C</$length[2345]/>, for instance, will be interpreted as C<$length> followed
125 by the character class C<[2345]>. If an array subscript is what you
126 want, you can avoid the warning by changing C</${length[2345]}/> to the
127 unsightly C</${\$length[2345]}/>, by renaming your array to something
128 that does not coincide with a built-in keyword, or by simply turning
129 off warnings with C<no warnings 'ambiguous';>.
131 =item Ambiguous use of -%s resolved as -&%s()
133 (S ambiguous) You wrote something like C<-foo>, which might be the
134 string C<"-foo">, or a call to the function C<foo>, negated. If you meant
135 the string, just write C<"-foo">. If you meant the function call,
138 =item '|' and '<' may not both be specified on command line
140 (F) An error peculiar to VMS. Perl does its own command line
141 redirection, and found that STDIN was a pipe, and that you also tried to
142 redirect STDIN using '<'. Only one STDIN stream to a customer, please.
144 =item '|' and '>' may not both be specified on command line
146 (F) An error peculiar to VMS. Perl does its own command line
147 redirection, and thinks you tried to redirect stdout both to a file and
148 into a pipe to another command. You need to choose one or the other,
149 though nothing's stopping you from piping into a program or Perl script
150 which 'splits' output into two streams, such as
152 open(OUT,">$ARGV[0]") or die "Can't write to $ARGV[0]: $!";
159 =item Applying %s to %s will act on scalar(%s)
161 (W misc) The pattern match (C<//>), substitution (C<s///>), and
162 transliteration (C<tr///>) operators work on scalar values. If you apply
163 one of them to an array or a hash, it will convert the array or hash to
164 a scalar value (the length of an array, or the population info of a
165 hash) and then work on that scalar value. This is probably not what
166 you meant to do. See L<perlfunc/grep> and L<perlfunc/map> for
169 =item Arg too short for msgsnd
171 (F) msgsnd() requires a string at least as long as sizeof(long).
173 =item Argument "%s" isn't numeric%s
175 (W numeric) The indicated string was fed as an argument to an operator
176 that expected a numeric value instead. If you're fortunate the message
177 will identify which operator was so unfortunate.
179 =item Argument list not closed for PerlIO layer "%s"
181 (W layer) When pushing a layer with arguments onto the Perl I/O
182 system you forgot the ) that closes the argument list. (Layers
183 take care of transforming data between external and internal
184 representations.) Perl stopped parsing the layer list at this
185 point and did not attempt to push this layer. If your program
186 didn't explicitly request the failing operation, it may be the
187 result of the value of the environment variable PERLIO.
189 =item Argument "%s" treated as 0 in increment (++)
191 (W numeric) The indicated string was fed as an argument to the C<++>
192 operator which expects either a number or a string matching
193 C</^[a-zA-Z]*[0-9]*\z/>. See L<perlop/Auto-increment and
194 Auto-decrement> for details.
196 =item Array @%s missing the @ in argument %d of %s()
198 (D deprecated) Really old Perl let you omit the @ on array names in some
199 spots. This is now heavily deprecated.
201 =item A sequence of multiple spaces in a charnames alias definition is deprecated
203 (D deprecated) You defined a character name which had multiple space
204 characters in a row. Change them to single spaces. Usually these
205 names are defined in the C<:alias> import argument to C<use charnames>, but
206 they could be defined by a translator installed into C<$^H{charnames}>.
207 See L<charnames/CUSTOM ALIASES>.
209 =item assertion botched: %s
211 (X) The malloc package that comes with Perl had an internal failure.
213 =item Assertion failed: file "%s"
215 (X) A general assertion failed. The file in question must be examined.
217 =item Assigning non-zero to $[ is no longer possible
219 (F) When the "array_base" feature is disabled (e.g., under C<use v5.16;>)
220 the special variable C<$[>, which is deprecated, is now a fixed zero value.
222 =item Assignment to both a list and a scalar
224 (F) If you assign to a conditional operator, the 2nd and 3rd arguments
225 must either both be scalars or both be lists. Otherwise Perl won't
226 know which context to supply to the right side.
228 =item A thread exited while %d threads were running
230 (W threads)(S) When using threaded Perl, a thread (not necessarily
231 the main thread) exited while there were still other threads running.
232 Usually it's a good idea first to collect the return values of the
233 created threads by joining them, and only then to exit from the main
234 thread. See L<threads>.
236 =item Attempt to access disallowed key '%s' in a restricted hash
238 (F) The failing code has attempted to get or set a key which is not in
239 the current set of allowed keys of a restricted hash.
241 =item Attempt to bless into a freed package
243 (F) You wrote C<bless $foo> with one argument after somehow causing
244 the current package to be freed. Perl cannot figure out what to
245 do, so it throws up in hands in despair.
247 =item Attempt to bless into a reference
249 (F) The CLASSNAME argument to the bless() operator is expected to be
250 the name of the package to bless the resulting object into. You've
251 supplied instead a reference to something: perhaps you wrote
257 bless $self, ref($proto) || $proto;
259 If you actually want to bless into the stringified version
260 of the reference supplied, you need to stringify it yourself, for
263 bless $self, "$proto";
265 =item Attempt to clear deleted array
267 (S debugging) An array was assigned to when it was being freed.
268 Freed values are not supposed to be visible to Perl code. This
269 can also happen if XS code calls C<av_clear> from a custom magic
270 callback on the array.
272 =item Attempt to delete disallowed key '%s' from a restricted hash
274 (F) The failing code attempted to delete from a restricted hash a key
275 which is not in its key set.
277 =item Attempt to delete readonly key '%s' from a restricted hash
279 (F) The failing code attempted to delete a key whose value has been
280 declared readonly from a restricted hash.
282 =item Attempt to free non-arena SV: 0x%x
284 (S internal) All SV objects are supposed to be allocated from arenas
285 that will be garbage collected on exit. An SV was discovered to be
286 outside any of those arenas.
288 =item Attempt to free nonexistent shared string '%s'%s
290 (S internal) Perl maintains a reference-counted internal table of
291 strings to optimize the storage and access of hash keys and other
292 strings. This indicates someone tried to decrement the reference count
293 of a string that can no longer be found in the table.
295 =item Attempt to free temp prematurely: SV 0x%x
297 (S debugging) Mortalized values are supposed to be freed by the
298 free_tmps() routine. This indicates that something else is freeing the
299 SV before the free_tmps() routine gets a chance, which means that the
300 free_tmps() routine will be freeing an unreferenced scalar when it does
303 =item Attempt to free unreferenced glob pointers
305 (S internal) The reference counts got screwed up on symbol aliases.
307 =item Attempt to free unreferenced scalar: SV 0x%x
309 (S internal) Perl went to decrement the reference count of a scalar to
310 see if it would go to 0, and discovered that it had already gone to 0
311 earlier, and should have been freed, and in fact, probably was freed.
312 This could indicate that SvREFCNT_dec() was called too many times, or
313 that SvREFCNT_inc() was called too few times, or that the SV was
314 mortalized when it shouldn't have been, or that memory has been
317 =item Attempt to join self
319 (F) You tried to join a thread from within itself, which is an
320 impossible task. You may be joining the wrong thread, or you may need
321 to move the join() to some other thread.
323 =item Attempt to pack pointer to temporary value
325 (W pack) You tried to pass a temporary value (like the result of a
326 function, or a computed expression) to the "p" pack() template. This
327 means the result contains a pointer to a location that could become
328 invalid anytime, even before the end of the current statement. Use
329 literals or global values as arguments to the "p" pack() template to
332 =item Attempt to reload %s aborted.
334 (F) You tried to load a file with C<use> or C<require> that failed to
335 compile once already. Perl will not try to compile this file again
336 unless you delete its entry from %INC. See L<perlfunc/require> and
339 =item Attempt to set length of freed array
341 (W misc) You tried to set the length of an array which has
342 been freed. You can do this by storing a reference to the
343 scalar representing the last index of an array and later
344 assigning through that reference. For example
346 $r = do {my @a; \$#a};
349 =item Attempt to use reference as lvalue in substr
351 (W substr) You supplied a reference as the first argument to substr()
352 used as an lvalue, which is pretty strange. Perhaps you forgot to
353 dereference it first. See L<perlfunc/substr>.
355 =item Attribute "locked" is deprecated
357 (D deprecated) You have used the attributes pragma to modify the
358 "locked" attribute on a code reference. The :locked attribute is
359 obsolete, has had no effect since 5005 threads were removed, and
360 will be removed in a future release of Perl 5.
362 =item Attribute "unique" is deprecated
364 (D deprecated) You have used the attributes pragma to modify
365 the "unique" attribute on an array, hash or scalar reference.
366 The :unique attribute has had no effect since Perl 5.8.8, and
367 will be removed in a future release of Perl 5.
369 =item Attribute prototype(%s) discards earlier prototype attribute in same sub
371 (W misc) A sub was declared as sub foo : prototype(A) : prototype(B) {}, for
372 example. Since each sub can only have one prototype, the earlier
373 declaration(s) are discarded while the last one is applied.
375 =item av_reify called on tied array
377 (S debugging) This indicates that something went wrong and Perl got I<very>
378 confused about C<@_> or C<@DB::args> being tied.
380 =item Bad arg length for %s, is %u, should be %d
382 (F) You passed a buffer of the wrong size to one of msgctl(), semctl()
383 or shmctl(). In C parlance, the correct sizes are, respectively,
384 S<sizeof(struct msqid_ds *)>, S<sizeof(struct semid_ds *)>, and
385 S<sizeof(struct shmid_ds *)>.
387 =item Bad evalled substitution pattern
389 (F) You've used the C</e> switch to evaluate the replacement for a
390 substitution, but perl found a syntax error in the code to evaluate,
391 most likely an unexpected right brace '}'.
393 =item Bad filehandle: %s
395 (F) A symbol was passed to something wanting a filehandle, but the
396 symbol has no filehandle associated with it. Perhaps you didn't do an
397 open(), or did it in another package.
399 =item Bad free() ignored
401 (S malloc) An internal routine called free() on something that had never
402 been malloc()ed in the first place. Mandatory, but can be disabled by
403 setting environment variable C<PERL_BADFREE> to 0.
405 This message can be seen quite often with DB_File on systems with "hard"
406 dynamic linking, like C<AIX> and C<OS/2>. It is a bug of C<Berkeley DB>
407 which is left unnoticed if C<DB> uses I<forgiving> system malloc().
411 (P) One of the internal hash routines was passed a null HV pointer.
413 =item Badly placed ()'s
415 (A) You've accidentally run your script through B<csh> instead
416 of Perl. Check the #! line, or manually feed your script into
419 =item Bad name after %s
421 (F) You started to name a symbol by using a package prefix, and then
422 didn't finish the symbol. In particular, you can't interpolate outside
431 $sym = "mypack::$var";
433 =item Bad plugin affecting keyword '%s'
435 (F) An extension using the keyword plugin mechanism violated the
438 =item Bad realloc() ignored
440 (S malloc) An internal routine called realloc() on something that
441 had never been malloc()ed in the first place. Mandatory, but can
442 be disabled by setting the environment variable C<PERL_BADFREE> to 1.
444 =item Bad symbol for array
446 (P) An internal request asked to add an array entry to something that
447 wasn't a symbol table entry.
449 =item Bad symbol for dirhandle
451 (P) An internal request asked to add a dirhandle entry to something
452 that wasn't a symbol table entry.
454 =item Bad symbol for filehandle
456 (P) An internal request asked to add a filehandle entry to something
457 that wasn't a symbol table entry.
459 =item Bad symbol for hash
461 (P) An internal request asked to add a hash entry to something that
462 wasn't a symbol table entry.
464 =item Bareword found in conditional
466 (W bareword) The compiler found a bareword where it expected a
467 conditional, which often indicates that an || or && was parsed as part
468 of the last argument of the previous construct, for example:
472 It may also indicate a misspelled constant that has been interpreted as
475 use constant TYPO => 1;
476 if (TYOP) { print "foo" }
478 The C<strict> pragma is useful in avoiding such errors.
480 =item Bareword "%s" not allowed while "strict subs" in use
482 (F) With "strict subs" in use, a bareword is only allowed as a
483 subroutine identifier, in curly brackets or to the left of the "=>"
484 symbol. Perhaps you need to predeclare a subroutine?
486 =item Bareword "%s" refers to nonexistent package
488 (W bareword) You used a qualified bareword of the form C<Foo::>, but the
489 compiler saw no other uses of that namespace before that point. Perhaps
490 you need to predeclare a package?
492 =item BEGIN failed--compilation aborted
494 (F) An untrapped exception was raised while executing a BEGIN
495 subroutine. Compilation stops immediately and the interpreter is
498 =item BEGIN not safe after errors--compilation aborted
500 (F) Perl found a C<BEGIN {}> subroutine (or a C<use> directive, which
501 implies a C<BEGIN {}>) after one or more compilation errors had already
502 occurred. Since the intended environment for the C<BEGIN {}> could not
503 be guaranteed (due to the errors), and since subsequent code likely
504 depends on its correct operation, Perl just gave up.
506 =item \1 better written as $1
508 (W syntax) Outside of patterns, backreferences live on as variables.
509 The use of backslashes is grandfathered on the right-hand side of a
510 substitution, but stylistically it's better to use the variable form
511 because other Perl programmers will expect it, and it works better if
512 there are more than 9 backreferences.
514 =item Binary number > 0b11111111111111111111111111111111 non-portable
516 (W portable) The binary number you specified is larger than 2**32-1
517 (4294967295) and therefore non-portable between systems. See
518 L<perlport> for more on portability concerns.
520 =item bind() on closed socket %s
522 (W closed) You tried to do a bind on a closed socket. Did you forget to
523 check the return value of your socket() call? See L<perlfunc/bind>.
525 =item binmode() on closed filehandle %s
527 (W unopened) You tried binmode() on a filehandle that was never opened.
528 Check your control flow and number of arguments.
530 =item "\b{" is deprecated; use "\b\{" or "\b[{]" instead in regex; marked by <-- HERE in m/%s/
532 =item "\B{" is deprecated; use "\B\{" or "\B[{]" instead in regex; marked by <-- HERE in m/%s/
534 (D deprecated) Use of an unescaped "{" immediately following
535 a C<\b> or C<\B> is now deprecated so as to reserve its use for Perl
536 itself in a future release. You can either precede the brace
537 with a backslash, or enclose it in square brackets; the latter
538 is the way to go if the pattern delimiters are C<{}>.
540 =item Bit vector size > 32 non-portable
542 (W portable) Using bit vector sizes larger than 32 is non-portable.
544 =item Bizarre copy of %s
546 (P) Perl detected an attempt to copy an internal value that is not
549 =item Bizarre SvTYPE [%d]
551 (P) When starting a new thread or returning values from a thread, Perl
552 encountered an invalid data type.
554 =item Buffer overflow in prime_env_iter: %s
556 (W internal) A warning peculiar to VMS. While Perl was preparing to
557 iterate over %ENV, it encountered a logical name or symbol definition
558 which was too long, so it was truncated to the string shown.
560 =item Callback called exit
562 (F) A subroutine invoked from an external package via call_sv()
563 exited by calling exit.
565 =item %s() called too early to check prototype
567 (W prototype) You've called a function that has a prototype before the
568 parser saw a definition or declaration for it, and Perl could not check
569 that the call conforms to the prototype. You need to either add an
570 early prototype declaration for the subroutine in question, or move the
571 subroutine definition ahead of the call to get proper prototype
572 checking. Alternatively, if you are certain that you're calling the
573 function correctly, you may put an ampersand before the name to avoid
574 the warning. See L<perlsub>.
576 =item Cannot compress integer in pack
578 (F) An argument to pack("w",...) was too large to compress. The BER
579 compressed integer format can only be used with positive integers, and you
580 attempted to compress Infinity or a very large number (> 1e308).
581 See L<perlfunc/pack>.
583 =item Cannot compress negative numbers in pack
585 (F) An argument to pack("w",...) was negative. The BER compressed integer
586 format can only be used with positive integers. See L<perlfunc/pack>.
588 =item Cannot convert a reference to %s to typeglob
590 (F) You manipulated Perl's symbol table directly, stored a reference
591 in it, then tried to access that symbol via conventional Perl syntax.
592 The access triggers Perl to autovivify that typeglob, but it there is
593 no legal conversion from that type of reference to a typeglob.
595 =item Cannot copy to %s
597 (P) Perl detected an attempt to copy a value to an internal type that cannot
598 be directly assigned to.
600 =item Cannot find encoding "%s"
602 (S io) You tried to apply an encoding that did not exist to a filehandle,
603 either with open() or binmode().
605 =item Cannot set tied @DB::args
607 (F) C<caller> tried to set C<@DB::args>, but found it tied. Tying C<@DB::args>
608 is not supported. (Before this error was added, it used to crash.)
610 =item Cannot tie unreifiable array
612 (P) You somehow managed to call C<tie> on an array that does not
613 keep a reference count on its arguments and cannot be made to
614 do so. Such arrays are not even supposed to be accessible to
615 Perl code, but are only used internally.
617 =item Can only compress unsigned integers in pack
619 (F) An argument to pack("w",...) was not an integer. The BER compressed
620 integer format can only be used with positive integers, and you attempted
621 to compress something else. See L<perlfunc/pack>.
623 =item Can't bless non-reference value
625 (F) Only hard references may be blessed. This is how Perl "enforces"
626 encapsulation of objects. See L<perlobj>.
628 =item Can't "break" in a loop topicalizer
630 (F) You called C<break>, but you're in a C<foreach> block rather than
631 a C<given> block. You probably meant to use C<next> or C<last>.
633 =item Can't "break" outside a given block
635 (F) You called C<break>, but you're not inside a C<given> block.
637 =item Can't call method "%s" on an undefined value
639 (F) You used the syntax of a method call, but the slot filled by the
640 object reference or package name contains an undefined value. Something
641 like this will reproduce the error:
644 process $BADREF 1,2,3;
645 $BADREF->process(1,2,3);
647 =item Can't call method "%s" on unblessed reference
649 (F) A method call must know in what package it's supposed to run. It
650 ordinarily finds this out from the object reference you supply, but you
651 didn't supply an object reference in this case. A reference isn't an
652 object reference until it has been blessed. See L<perlobj>.
654 =item Can't call method "%s" without a package or object reference
656 (F) You used the syntax of a method call, but the slot filled by the
657 object reference or package name contains an expression that returns a
658 defined value which is neither an object reference nor a package name.
659 Something like this will reproduce the error:
662 process $BADREF 1,2,3;
663 $BADREF->process(1,2,3);
665 =item Can't call mro_isa_changed_in() on anonymous symbol table
667 (P) Perl got confused as to whether a hash was a plain hash or a
668 symbol table hash when trying to update @ISA caches.
670 =item Can't call mro_method_changed_in() on anonymous symbol table
672 (F) An XS module tried to call C<mro_method_changed_in> on a hash that was
673 not attached to the symbol table.
675 =item Can't chdir to %s
677 (F) You called C<perl -x/foo/bar>, but F</foo/bar> is not a directory
678 that you can chdir to, possibly because it doesn't exist.
680 =item Can't check filesystem of script "%s" for nosuid
682 (P) For some reason you can't check the filesystem of the script for
685 =item Can't coerce %s to %s in %s
687 (F) Certain types of SVs, in particular real symbol table entries
688 (typeglobs), can't be forced to stop being what they are. So you can't
698 but then $foo no longer contains a glob.
700 =item Can't "continue" outside a when block
702 (F) You called C<continue>, but you're not inside a C<when>
705 =item Can't create pipe mailbox
707 (P) An error peculiar to VMS. The process is suffering from exhausted
708 quotas or other plumbing problems.
710 =item Can't declare %s in "%s"
712 (F) Only scalar, array, and hash variables may be declared as "my", "our" or
713 "state" variables. They must have ordinary identifiers as names.
715 =item Can't "default" outside a topicalizer
717 (F) You have used a C<default> block that is neither inside a
718 C<foreach> loop nor a C<given> block. (Note that this error is
719 issued on exit from the C<default> block, so you won't get the
720 error if you use an explicit C<continue>.)
722 =item Can't do inplace edit: %s is not a regular file
724 (S inplace) You tried to use the B<-i> switch on a special file, such as
725 a file in /dev, a FIFO or an uneditable directory. The file was ignored.
727 =item Can't do inplace edit on %s: %s
729 (S inplace) The creation of the new file failed for the indicated
732 =item Can't do inplace edit without backup
734 (F) You're on a system such as MS-DOS that gets confused if you try
735 reading from a deleted (but still opened) file. You have to say
736 C<-i.bak>, or some such.
738 =item Can't do inplace edit: %s would not be unique
740 (S inplace) Your filesystem does not support filenames longer than 14
741 characters and Perl was unable to create a unique filename during
742 inplace editing with the B<-i> switch. The file was ignored.
744 =item Can't do waitpid with flags
746 (F) This machine doesn't have either waitpid() or wait4(), so only
747 waitpid() without flags is emulated.
749 =item Can't emulate -%s on #! line
751 (F) The #! line specifies a switch that doesn't make sense at this
752 point. For example, it'd be kind of silly to put a B<-x> on the #!
755 =item Can't %s %s-endian %ss on this platform
757 (F) Your platform's byte-order is neither big-endian nor little-endian,
758 or it has a very strange pointer size. Packing and unpacking big- or
759 little-endian floating point values and pointers may not be possible.
760 See L<perlfunc/pack>.
762 =item Can't exec "%s": %s
764 (W exec) A system(), exec(), or piped open call could not execute the
765 named program for the indicated reason. Typical reasons include: the
766 permissions were wrong on the file, the file wasn't found in
767 C<$ENV{PATH}>, the executable in question was compiled for another
768 architecture, or the #! line in a script points to an interpreter that
769 can't be run for similar reasons. (Or maybe your system doesn't support
774 (F) Perl was trying to execute the indicated program for you because
775 that's what the #! line said. If that's not what you wanted, you may
776 need to mention "perl" on the #! line somewhere.
778 =item Can't execute %s
780 (F) You used the B<-S> switch, but the copies of the script to execute
781 found in the PATH did not have correct permissions.
783 =item Can't find an opnumber for "%s"
785 (F) A string of a form C<CORE::word> was given to prototype(), but there
786 is no builtin with the name C<word>.
788 =item Can't find %s character property "%s"
790 (F) You used C<\p{}> or C<\P{}> but the character property by that name
791 could not be found. Maybe you misspelled the name of the property?
792 See L<perluniprops/Properties accessible through \p{} and \P{}>
793 for a complete list of available official properties.
795 =item Can't find label %s
797 (F) You said to goto a label that isn't mentioned anywhere that it's
798 possible for us to go to. See L<perlfunc/goto>.
800 =item Can't find %s on PATH
802 (F) You used the B<-S> switch, but the script to execute could not be
805 =item Can't find %s on PATH, '.' not in PATH
807 (F) You used the B<-S> switch, but the script to execute could not be
808 found in the PATH, or at least not with the correct permissions. The
809 script exists in the current directory, but PATH prohibits running it.
811 =item Can't find string terminator %s anywhere before EOF
813 (F) Perl strings can stretch over multiple lines. This message means
814 that the closing delimiter was omitted. Because bracketed quotes count
815 nesting levels, the following is missing its final parenthesis:
817 print q(The character '(' starts a side comment.);
819 If you're getting this error from a here-document, you may have
820 included unseen whitespace before or after your closing tag or there
821 may not be a linebreak after it. A good programmer's editor will have
822 a way to help you find these characters (or lack of characters). See
823 L<perlop> for the full details on here-documents.
825 =item Can't find Unicode property definition "%s"
827 (F) You may have tried to use C<\p> which means a Unicode
828 property (for example C<\p{Lu}> matches all uppercase
829 letters). If you did mean to use a Unicode property, see
830 L<perluniprops/Properties accessible through \p{} and \P{}>
831 for a complete list of available properties. If you didn't
832 mean to use a Unicode property, escape the C<\p>, either by
833 C<\\p> (just the C<\p>) or by C<\Q\p> (the rest of the string, or
838 (F) A fatal error occurred while trying to fork while opening a
841 =item Can't fork, trying again in 5 seconds
843 (W pipe) A fork in a piped open failed with EAGAIN and will be retried
846 =item Can't get filespec - stale stat buffer?
848 (S) A warning peculiar to VMS. This arises because of the difference
849 between access checks under VMS and under the Unix model Perl assumes.
850 Under VMS, access checks are done by filename, rather than by bits in
851 the stat buffer, so that ACLs and other protections can be taken into
852 account. Unfortunately, Perl assumes that the stat buffer contains all
853 the necessary information, and passes it, instead of the filespec, to
854 the access-checking routine. It will try to retrieve the filespec using
855 the device name and FID present in the stat buffer, but this works only
856 if you haven't made a subsequent call to the CRTL stat() routine,
857 because the device name is overwritten with each call. If this warning
858 appears, the name lookup failed, and the access-checking routine gave up
859 and returned FALSE, just to be conservative. (Note: The access-checking
860 routine knows about the Perl C<stat> operator and file tests, so you
861 shouldn't ever see this warning in response to a Perl command; it arises
862 only if some internal code takes stat buffers lightly.)
864 =item Can't get pipe mailbox device name
866 (P) An error peculiar to VMS. After creating a mailbox to act as a
867 pipe, Perl can't retrieve its name for later use.
869 =item Can't get SYSGEN parameter value for MAXBUF
871 (P) An error peculiar to VMS. Perl asked $GETSYI how big you want your
872 mailbox buffers to be, and didn't get an answer.
874 =item Can't "goto" into the middle of a foreach loop
876 (F) A "goto" statement was executed to jump into the middle of a foreach
877 loop. You can't get there from here. See L<perlfunc/goto>.
879 =item Can't "goto" out of a pseudo block
881 (F) A "goto" statement was executed to jump out of what might look like
882 a block, except that it isn't a proper block. This usually occurs if
883 you tried to jump out of a sort() block or subroutine, which is a no-no.
884 See L<perlfunc/goto>.
886 =item Can't goto subroutine from an eval-%s
888 (F) The "goto subroutine" call can't be used to jump out of an eval
891 =item Can't goto subroutine from a sort sub (or similar callback)
893 (F) The "goto subroutine" call can't be used to jump out of the
894 comparison sub for a sort(), or from a similar callback (such
895 as the reduce() function in List::Util).
897 =item Can't goto subroutine outside a subroutine
899 (F) The deeply magical "goto subroutine" call can only replace one
900 subroutine call for another. It can't manufacture one out of whole
901 cloth. In general you should be calling it out of only an AUTOLOAD
902 routine anyway. See L<perlfunc/goto>.
904 =item Can't ignore signal CHLD, forcing to default
906 (W signal) Perl has detected that it is being run with the SIGCHLD
907 signal (sometimes known as SIGCLD) disabled. Since disabling this
908 signal will interfere with proper determination of exit status of child
909 processes, Perl has reset the signal to its default value. This
910 situation typically indicates that the parent program under which Perl
911 may be running (e.g. cron) is being very careless.
913 =item Can't kill a non-numeric process ID
915 (F) Process identifiers must be (signed) integers. It is a fatal error to
916 attempt to kill() an undefined, empty-string or otherwise non-numeric
919 =item Can't "last" outside a loop block
921 (F) A "last" statement was executed to break out of the current block,
922 except that there's this itty bitty problem called there isn't a current
923 block. Note that an "if" or "else" block doesn't count as a "loopish"
924 block, as doesn't a block given to sort(), map() or grep(). You can
925 usually double the curlies to get the same effect though, because the
926 inner curlies will be considered a block that loops once. See
929 =item Can't linearize anonymous symbol table
931 (F) Perl tried to calculate the method resolution order (MRO) of a
932 package, but failed because the package stash has no name.
934 =item Can't load '%s' for module %s
936 (F) The module you tried to load failed to load a dynamic extension.
937 This may either mean that you upgraded your version of perl to one
938 that is incompatible with your old dynamic extensions (which is known
939 to happen between major versions of perl), or (more likely) that your
940 dynamic extension was built against an older version of the library
941 that is installed on your system. You may need to rebuild your old
944 =item Can't localize lexical variable %s
946 (F) You used local on a variable name that was previously declared as a
947 lexical variable using "my" or "state". This is not allowed. If you
948 want to localize a package variable of the same name, qualify it with
951 =item Can't localize through a reference
953 (F) You said something like C<local $$ref>, which Perl can't currently
954 handle, because when it goes to restore the old value of whatever $ref
955 pointed to after the scope of the local() is finished, it can't be sure
956 that $ref will still be a reference.
958 =item Can't locate %s
960 (F) You said to C<do> (or C<require>, or C<use>) a file that couldn't be found.
961 Perl looks for the file in all the locations mentioned in @INC, unless
962 the file name included the full path to the file. Perhaps you need
963 to set the PERL5LIB or PERL5OPT environment variable to say where the
964 extra library is, or maybe the script needs to add the library name
965 to @INC. Or maybe you just misspelled the name of the file. See
966 L<perlfunc/require> and L<lib>.
968 =item Can't locate auto/%s.al in @INC
970 (F) A function (or method) was called in a package which allows
971 autoload, but there is no function to autoload. Most probable causes
972 are a misprint in a function/method name or a failure to C<AutoSplit>
973 the file, say, by doing C<make install>.
975 =item Can't locate loadable object for module %s in @INC
977 (F) The module you loaded is trying to load an external library, like
978 for example, F<foo.so> or F<bar.dll>, but the L<DynaLoader> module was
979 unable to locate this library. See L<DynaLoader>.
981 =item Can't locate object method "%s" via package "%s"
983 (F) You called a method correctly, and it correctly indicated a package
984 functioning as a class, but that package doesn't define that particular
985 method, nor does any of its base classes. See L<perlobj>.
987 =item Can't locate package %s for @%s::ISA
989 (W syntax) The @ISA array contained the name of another package that
990 doesn't seem to exist.
992 =item Can't locate PerlIO%s
994 (F) You tried to use in open() a PerlIO layer that does not exist,
995 e.g. open(FH, ">:nosuchlayer", "somefile").
997 =item Can't make list assignment to %ENV on this system
999 (F) List assignment to %ENV is not supported on some systems, notably
1002 =item Can't make loaded symbols global on this platform while loading %s
1004 (S) A module passed the flag 0x01 to DynaLoader::dl_load_file() to request
1005 that symbols from the stated file are made available globally within the
1006 process, but that functionality is not available on this platform. Whilst
1007 the module likely will still work, this may prevent the perl interpreter
1008 from loading other XS-based extensions which need to link directly to
1009 functions defined in the C or XS code in the stated file.
1011 =item Can't modify %s in %s
1013 (F) You aren't allowed to assign to the item indicated, or otherwise try
1014 to change it, such as with an auto-increment.
1016 =item Can't modify nonexistent substring
1018 (P) The internal routine that does assignment to a substr() was handed
1021 =item Can't modify non-lvalue subroutine call
1023 (F) Subroutines meant to be used in lvalue context should be declared as
1024 such. See L<perlsub/"Lvalue subroutines">.
1026 =item Can't msgrcv to read-only var
1028 (F) The target of a msgrcv must be modifiable to be used as a receive
1031 =item Can't "next" outside a loop block
1033 (F) A "next" statement was executed to reiterate the current block, but
1034 there isn't a current block. Note that an "if" or "else" block doesn't
1035 count as a "loopish" block, as doesn't a block given to sort(), map() or
1036 grep(). You can usually double the curlies to get the same effect
1037 though, because the inner curlies will be considered a block that loops
1038 once. See L<perlfunc/next>.
1042 (F) You tried to run a perl built with MAD support with
1043 the PERL_XMLDUMP environment variable set, but the file
1044 named by that variable could not be opened.
1046 =item Can't open %s: %s
1048 (S inplace) The implicit opening of a file through use of the C<< <> >>
1049 filehandle, either implicitly under the C<-n> or C<-p> command-line
1050 switches, or explicitly, failed for the indicated reason. Usually
1051 this is because you don't have read permission for a file which
1052 you named on the command line.
1054 (F) You tried to call perl with the B<-e> switch, but F</dev/null> (or
1055 your operating system's equivalent) could not be opened.
1057 =item Can't open a reference
1059 (W io) You tried to open a scalar reference for reading or writing,
1060 using the 3-arg open() syntax:
1064 but your version of perl is compiled without perlio, and this form of
1065 open is not supported.
1067 =item Can't open bidirectional pipe
1069 (W pipe) You tried to say C<open(CMD, "|cmd|")>, which is not supported.
1070 You can try any of several modules in the Perl library to do this, such
1071 as IPC::Open2. Alternately, direct the pipe's output to a file using
1072 ">", and then read it in under a different file handle.
1074 =item Can't open error file %s as stderr
1076 (F) An error peculiar to VMS. Perl does its own command line
1077 redirection, and couldn't open the file specified after '2>' or '2>>' on
1078 the command line for writing.
1080 =item Can't open input file %s as stdin
1082 (F) An error peculiar to VMS. Perl does its own command line
1083 redirection, and couldn't open the file specified after '<' on the
1084 command line for reading.
1086 =item Can't open output file %s as stdout
1088 (F) An error peculiar to VMS. Perl does its own command line
1089 redirection, and couldn't open the file specified after '>' or '>>' on
1090 the command line for writing.
1092 =item Can't open output pipe (name: %s)
1094 (P) An error peculiar to VMS. Perl does its own command line
1095 redirection, and couldn't open the pipe into which to send data destined
1098 =item Can't open perl script "%s": %s
1100 (F) The script you specified can't be opened for the indicated reason.
1102 If you're debugging a script that uses #!, and normally relies on the
1103 shell's $PATH search, the -S option causes perl to do that search, so
1104 you don't have to type the path or C<`which $scriptname`>.
1106 =item Can't read CRTL environ
1108 (S) A warning peculiar to VMS. Perl tried to read an element of %ENV
1109 from the CRTL's internal environment array and discovered the array was
1110 missing. You need to figure out where your CRTL misplaced its environ
1111 or define F<PERL_ENV_TABLES> (see L<perlvms>) so that environ is not
1114 =item Can't "redo" outside a loop block
1116 (F) A "redo" statement was executed to restart the current block, but
1117 there isn't a current block. Note that an "if" or "else" block doesn't
1118 count as a "loopish" block, as doesn't a block given to sort(), map()
1119 or grep(). You can usually double the curlies to get the same effect
1120 though, because the inner curlies will be considered a block that
1121 loops once. See L<perlfunc/redo>.
1123 =item Can't remove %s: %s, skipping file
1125 (S inplace) You requested an inplace edit without creating a backup
1126 file. Perl was unable to remove the original file to replace it with
1127 the modified file. The file was left unmodified.
1129 =item Can't rename %s to %s: %s, skipping file
1131 (S inplace) The rename done by the B<-i> switch failed for some reason,
1132 probably because you don't have write permission to the directory.
1134 =item Can't reopen input pipe (name: %s) in binary mode
1136 (P) An error peculiar to VMS. Perl thought stdin was a pipe, and tried
1137 to reopen it to accept binary data. Alas, it failed.
1139 =item Can't reset %ENV on this system
1141 (F) You called C<reset('E')> or similar, which tried to reset
1142 all variables in the current package beginning with "E". In
1143 the main package, that includes %ENV. Resetting %ENV is not
1144 supported on some systems, notably VMS.
1146 =item Can't resolve method "%s" overloading "%s" in package "%s"
1148 (F)(P) Error resolving overloading specified by a method name (as
1149 opposed to a subroutine reference): no such method callable via the
1150 package. If the method name is C<???>, this is an internal error.
1152 =item Can't return %s from lvalue subroutine
1154 (F) Perl detected an attempt to return illegal lvalues (such as
1155 temporary or readonly values) from a subroutine used as an lvalue. This
1158 =item Can't return outside a subroutine
1160 (F) The return statement was executed in mainline code, that is, where
1161 there was no subroutine call to return out of. See L<perlsub>.
1163 =item Can't return %s to lvalue scalar context
1165 (F) You tried to return a complete array or hash from an lvalue
1166 subroutine, but you called the subroutine in a way that made Perl
1167 think you meant to return only one value. You probably meant to
1168 write parentheses around the call to the subroutine, which tell
1169 Perl that the call should be in list context.
1171 =item Can't stat script "%s"
1173 (P) For some reason you can't fstat() the script even though you have it
1174 open already. Bizarre.
1176 =item Can't take log of %g
1178 (F) For ordinary real numbers, you can't take the logarithm of a
1179 negative number or zero. There's a Math::Complex package that comes
1180 standard with Perl, though, if you really want to do that for the
1183 =item Can't take sqrt of %g
1185 (F) For ordinary real numbers, you can't take the square root of a
1186 negative number. There's a Math::Complex package that comes standard
1187 with Perl, though, if you really want to do that.
1189 =item Can't undef active subroutine
1191 (F) You can't undefine a routine that's currently running. You can,
1192 however, redefine it while it's running, and you can even undef the
1193 redefined subroutine while the old routine is running. Go figure.
1195 =item Can't upgrade %s (%d) to %d
1197 (P) The internal sv_upgrade routine adds "members" to an SV, making it
1198 into a more specialized kind of SV. The top several SV types are so
1199 specialized, however, that they cannot be interconverted. This message
1200 indicates that such a conversion was attempted.
1202 =item Can't use '%c' after -mname
1204 (F) You tried to call perl with the B<-m> switch, but you put something
1205 other than "=" after the module name.
1207 =item Can't use anonymous symbol table for method lookup
1209 (F) The internal routine that does method lookup was handed a symbol
1210 table that doesn't have a name. Symbol tables can become anonymous
1211 for example by undefining stashes: C<undef %Some::Package::>.
1213 =item Can't use an undefined value as %s reference
1215 (F) A value used as either a hard reference or a symbolic reference must
1216 be a defined value. This helps to delurk some insidious errors.
1218 =item Can't use bareword ("%s") as %s ref while "strict refs" in use
1220 (F) Only hard references are allowed by "strict refs". Symbolic
1221 references are disallowed. See L<perlref>.
1223 =item Can't use %! because Errno.pm is not available
1225 (F) The first time the C<%!> hash is used, perl automatically loads the
1226 Errno.pm module. The Errno module is expected to tie the %! hash to
1227 provide symbolic names for C<$!> errno values.
1229 =item Can't use both '<' and '>' after type '%c' in %s
1231 (F) A type cannot be forced to have both big-endian and little-endian
1232 byte-order at the same time, so this combination of modifiers is not
1233 allowed. See L<perlfunc/pack>.
1235 =item Can't use %s for loop variable
1237 (F) Only a simple scalar variable may be used as a loop variable on a
1240 =item Can't use global %s in "%s"
1242 (F) You tried to declare a magical variable as a lexical variable. This
1243 is not allowed, because the magic can be tied to only one location
1244 (namely the global variable) and it would be incredibly confusing to
1245 have variables in your program that looked like magical variables but
1248 =item Can't use '%c' in a group with different byte-order in %s
1250 (F) You attempted to force a different byte-order on a type
1251 that is already inside a group with a byte-order modifier.
1252 For example you cannot force little-endianness on a type that
1253 is inside a big-endian group.
1255 =item Can't use "my %s" in sort comparison
1257 (F) The global variables $a and $b are reserved for sort comparisons.
1258 You mentioned $a or $b in the same line as the <=> or cmp operator,
1259 and the variable had earlier been declared as a lexical variable.
1260 Either qualify the sort variable with the package name, or rename the
1263 =item Can't use %s ref as %s ref
1265 (F) You've mixed up your reference types. You have to dereference a
1266 reference of the type needed. You can use the ref() function to
1267 test the type of the reference, if need be.
1269 =item Can't use string ("%s") as %s ref while "strict refs" in use
1271 =item Can't use string ("%s"...) as %s ref while "strict refs" in use
1273 (F) You've told Perl to dereference a string, something which
1274 C<use strict> blocks to prevent it happening accidentally. See
1275 L<perlref/"Symbolic references">. This can be triggered by an C<@> or C<$>
1276 in a double-quoted string immediately before interpolating a variable,
1277 for example in C<"user @$twitter_id">, which says to treat the contents
1278 of C<$twitter_id> as an array reference; use a C<\> to have a literal C<@>
1279 symbol followed by the contents of C<$twitter_id>: C<"user \@$twitter_id">.
1281 =item Can't use subscript on %s
1283 (F) The compiler tried to interpret a bracketed expression as a
1284 subscript. But to the left of the brackets was an expression that
1285 didn't look like a hash or array reference, or anything else subscriptable.
1287 =item Can't use \%c to mean $%c in expression
1289 (W syntax) In an ordinary expression, backslash is a unary operator that
1290 creates a reference to its argument. The use of backslash to indicate a
1291 backreference to a matched substring is valid only as part of a regular
1292 expression pattern. Trying to do this in ordinary Perl code produces a
1293 value that prints out looking like SCALAR(0xdecaf). Use the $1 form
1296 =item Can't weaken a nonreference
1298 (F) You attempted to weaken something that was not a reference. Only
1299 references can be weakened.
1301 =item Can't "when" outside a topicalizer
1303 (F) You have used a when() block that is neither inside a C<foreach>
1304 loop nor a C<given> block. (Note that this error is issued on exit
1305 from the C<when> block, so you won't get the error if the match fails,
1306 or if you use an explicit C<continue>.)
1308 =item Can't x= to read-only value
1310 (F) You tried to repeat a constant value (often the undefined value)
1311 with an assignment operator, which implies modifying the value itself.
1312 Perhaps you need to copy the value to a temporary, and repeat that.
1314 =item Character following "\c" must be ASCII
1316 (F)(D deprecated, syntax) In C<\cI<X>>, I<X> must be an ASCII character.
1317 It is planned to make this fatal in all instances in Perl v5.20. In
1318 the cases where it isn't fatal, the character this evaluates to is
1319 derived by exclusive or'ing the code point of this character with 0x40.
1321 Note that non-alphabetic ASCII characters are discouraged here as well,
1322 and using non-printable ones will be deprecated starting in v5.18.
1324 =item Character in 'C' format wrapped in pack
1330 where $x is either less than 0 or more than 255; the C<"C"> format is
1331 only for encoding native operating system characters (ASCII, EBCDIC,
1332 and so on) and not for Unicode characters, so Perl behaved as if you meant
1336 If you actually want to pack Unicode codepoints, use the C<"U"> format
1339 =item Character in 'c' format wrapped in pack
1345 where $x is either less than -128 or more than 127; the C<"c"> format
1346 is only for encoding native operating system characters (ASCII, EBCDIC,
1347 and so on) and not for Unicode characters, so Perl behaved as if you meant
1349 pack("c", $x & 255);
1351 If you actually want to pack Unicode codepoints, use the C<"U"> format
1354 =item Character in '%c' format wrapped in unpack
1356 (W unpack) You tried something like
1358 unpack("H", "\x{2a1}")
1360 where the format expects to process a byte (a character with a value
1361 below 256), but a higher value was provided instead. Perl uses the
1362 value modulus 256 instead, as if you had provided:
1364 unpack("H", "\x{a1}")
1366 =item Character in 'W' format wrapped in pack
1372 where $x is either less than 0 or more than 255. However, C<U0>-mode
1373 expects all values to fall in the interval [0, 255], so Perl behaved
1376 pack("U0W", $x & 255)
1378 =item Character(s) in '%c' format wrapped in pack
1380 (W pack) You tried something like
1382 pack("u", "\x{1f3}b")
1384 where the format expects to process a sequence of bytes (character with a
1385 value below 256), but some of the characters had a higher value. Perl
1386 uses the character values modulus 256 instead, as if you had provided:
1388 pack("u", "\x{f3}b")
1390 =item Character(s) in '%c' format wrapped in unpack
1392 (W unpack) You tried something like
1394 unpack("s", "\x{1f3}b")
1396 where the format expects to process a sequence of bytes (character with a
1397 value below 256), but some of the characters had a higher value. Perl
1398 uses the character values modulus 256 instead, as if you had provided:
1400 unpack("s", "\x{f3}b")
1402 =item "\c{" is deprecated and is more clearly written as ";"
1404 (D deprecated, syntax) The C<\cI<X>> construct is intended to be a way
1405 to specify non-printable characters. You used it with a "{" which
1406 evaluates to ";", which is printable. It is planned to remove the
1407 ability to specify a semi-colon this way in Perl 5.20. Just use a
1408 semi-colon or a backslash-semi-colon without the "\c".
1410 =item "\c%c" is more clearly written simply as "%s"
1412 (W syntax) The C<\cI<X>> construct is intended to be a way to specify
1413 non-printable characters. You used it for a printable one, which is better
1414 written as simply itself, perhaps preceded by a backslash for non-word
1417 =item Cloning substitution context is unimplemented
1419 (F) Creating a new thread inside the C<s///> operator is not supported.
1421 =item closedir() attempted on invalid dirhandle %s
1423 (W io) The dirhandle you tried to close is either closed or not really
1424 a dirhandle. Check your control flow.
1426 =item close() on unopened filehandle %s
1428 (W unopened) You tried to close a filehandle that was never opened.
1430 =item Closure prototype called
1432 (F) If a closure has attributes, the subroutine passed to an attribute
1433 handler is the prototype that is cloned when a new closure is created.
1434 This subroutine cannot be called.
1436 =item Code missing after '/'
1438 (F) You had a (sub-)template that ends with a '/'. There must be
1439 another template code following the slash. See L<perlfunc/pack>.
1441 =item Code point 0x%X is not Unicode, all \p{} matches fail; all \P{} matches
1444 =item Code point 0x%X is not Unicode, may not be portable
1446 (S utf8, non_unicode) You had a code point above the Unicode maximum
1449 Perl allows strings to contain a superset of Unicode code points, up
1450 to the limit of what is storable in an unsigned integer on your system,
1451 but these may not be accepted by other languages/systems. At one time,
1452 it was legal in some standards to have code points up to 0x7FFF_FFFF,
1453 but not higher. Code points above 0xFFFF_FFFF require larger than a
1456 None of the Unicode or Perl-defined properties will match a non-Unicode
1457 code point. For example,
1459 chr(0x7FF_FFFF) =~ /\p{Any}/
1461 will not match, because the code point is not in Unicode. But
1463 chr(0x7FF_FFFF) =~ /\P{Any}/
1467 This may be counterintuitive at times, as both these fail:
1469 chr(0x110000) =~ /\p{ASCII_Hex_Digit=True}/ # Fails.
1470 chr(0x110000) =~ /\p{ASCII_Hex_Digit=False}/ # Also fails!
1472 and both these succeed:
1474 chr(0x110000) =~ /\P{ASCII_Hex_Digit=True}/ # Succeeds.
1475 chr(0x110000) =~ /\P{ASCII_Hex_Digit=False}/ # Also succeeds!
1477 =item %s: Command not found
1479 (A) You've accidentally run your script through B<csh> or another shell
1480 shell instead of Perl. Check the #! line, or manually feed your script
1481 into Perl yourself. The #! line at the top of your file could look like
1485 =item Compilation failed in require
1487 (F) Perl could not compile a file specified in a C<require> statement.
1488 Perl uses this generic message when none of the errors that it
1489 encountered were severe enough to halt compilation immediately.
1491 =item Complex regular subexpression recursion limit (%d) exceeded
1493 (W regexp) The regular expression engine uses recursion in complex
1494 situations where back-tracking is required. Recursion depth is limited
1495 to 32766, or perhaps less in architectures where the stack cannot grow
1496 arbitrarily. ("Simple" and "medium" situations are handled without
1497 recursion and are not subject to a limit.) Try shortening the string
1498 under examination; looping in Perl code (e.g. with C<while>) rather than
1499 in the regular expression engine; or rewriting the regular expression so
1500 that it is simpler or backtracks less. (See L<perlfaq2> for information
1501 on I<Mastering Regular Expressions>.)
1503 =item cond_broadcast() called on unlocked variable
1505 (W threads) Within a thread-enabled program, you tried to
1506 call cond_broadcast() on a variable which wasn't locked.
1507 The cond_broadcast() function is used to wake up another thread
1508 that is waiting in a cond_wait(). To ensure that the signal isn't
1509 sent before the other thread has a chance to enter the wait, it
1510 is usual for the signaling thread first to wait for a lock on
1511 variable. This lock attempt will only succeed after the other
1512 thread has entered cond_wait() and thus relinquished the lock.
1514 =item cond_signal() called on unlocked variable
1516 (W threads) Within a thread-enabled program, you tried to
1517 call cond_signal() on a variable which wasn't locked. The
1518 cond_signal() function is used to wake up another thread that
1519 is waiting in a cond_wait(). To ensure that the signal isn't
1520 sent before the other thread has a chance to enter the wait, it
1521 is usual for the signaling thread first to wait for a lock on
1522 variable. This lock attempt will only succeed after the other
1523 thread has entered cond_wait() and thus relinquished the lock.
1525 =item connect() on closed socket %s
1527 (W closed) You tried to do a connect on a closed socket. Did you forget
1528 to check the return value of your socket() call? See
1529 L<perlfunc/connect>.
1531 =item Constant(%s): Call to &{$^H{%s}} did not return a defined value
1533 (F) The subroutine registered to handle constant overloading
1534 (see L<overload>) or a custom charnames handler (see
1535 L<charnames/CUSTOM TRANSLATORS>) returned an undefined value.
1537 =item Constant(%s): $^H{%s} is not defined
1539 (F) The parser found inconsistencies while attempting to define an
1540 overloaded constant. Perhaps you forgot to load the corresponding
1541 L<overload> pragma?.
1543 =item Constant is not %s reference
1545 (F) A constant value (perhaps declared using the C<use constant> pragma)
1546 is being dereferenced, but it amounts to the wrong type of reference.
1547 The message indicates the type of reference that was expected. This
1548 usually indicates a syntax error in dereferencing the constant value.
1549 See L<perlsub/"Constant Functions"> and L<constant>.
1551 =item Constant subroutine %s redefined
1553 (W redefine)(S) You redefined a subroutine which had previously
1554 been eligible for inlining. See L<perlsub/"Constant Functions">
1555 for commentary and workarounds.
1557 =item Constant subroutine %s undefined
1559 (W misc) You undefined a subroutine which had previously been eligible
1560 for inlining. See L<perlsub/"Constant Functions"> for commentary and
1563 =item Constant(%s) unknown
1565 (F) The parser found inconsistencies either while attempting
1566 to define an overloaded constant, or when trying to find the
1567 character name specified in the C<\N{...}> escape. Perhaps you
1568 forgot to load the corresponding L<overload> pragma?.
1570 =item Copy method did not return a reference
1572 (F) The method which overloads "=" is buggy. See
1573 L<overload/Copy Constructor>.
1575 =item &CORE::%s cannot be called directly
1577 (F) You tried to call a subroutine in the C<CORE::> namespace
1578 with C<&foo> syntax or through a reference. Some subroutines
1579 in this package cannot yet be called that way, but must be
1580 called as barewords. Something like this will work:
1582 BEGIN { *shove = \&CORE::push; }
1583 shove @array, 1,2,3; # pushes on to @array
1585 =item CORE::%s is not a keyword
1587 (F) The CORE:: namespace is reserved for Perl keywords.
1589 =item Corrupted regexp opcode %d > %d
1591 (P) This is either an error in Perl, or, if you're using
1592 one, your L<custom regular expression engine|perlreapi>. If not the
1593 latter, report the problem through the L<perlbug> utility.
1595 =item corrupted regexp pointers
1597 (P) The regular expression engine got confused by what the regular
1598 expression compiler gave it.
1600 =item corrupted regexp program
1602 (P) The regular expression engine got passed a regexp program without a
1605 =item Corrupt malloc ptr 0x%x at 0x%x
1607 (P) The malloc package that comes with Perl had an internal failure.
1609 =item Count after length/code in unpack
1611 (F) You had an unpack template indicating a counted-length string, but
1612 you have also specified an explicit size for the string. See
1615 =item Deep recursion on anonymous subroutine
1617 =item Deep recursion on subroutine "%s"
1619 (W recursion) This subroutine has called itself (directly or indirectly)
1620 100 times more than it has returned. This probably indicates an
1621 infinite recursion, unless you're writing strange benchmark programs, in
1622 which case it indicates something else.
1624 This threshold can be changed from 100, by recompiling the F<perl> binary,
1625 setting the C pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value.
1627 =item defined(@array) is deprecated
1629 (D deprecated) defined() is not usually useful on arrays because it
1630 checks for an undefined I<scalar> value. If you want to see if the
1631 array is empty, just use C<if (@array) { # not empty }> for example.
1633 =item defined(%hash) is deprecated
1635 (D deprecated) C<defined()> is not usually right on hashes and has been
1636 discouraged since 5.004.
1638 Although C<defined %hash> is false on a plain not-yet-used hash, it
1639 becomes true in several non-obvious circumstances, including iterators,
1640 weak references, stash names, even remaining true after C<undef %hash>.
1641 These things make C<defined %hash> fairly useless in practice.
1643 If a check for non-empty is what you wanted then just put it in boolean
1644 context (see L<perldata/Scalar values>):
1650 If you had C<defined %Foo::Bar::QUUX> to check whether such a package
1651 variable exists then that's never really been reliable, and isn't
1652 a good way to enquire about the features of a package, or whether
1656 =item (?(DEFINE)....) does not allow branches in regex; marked by <-- HERE in
1659 (F) You used something like C<(?(DEFINE)...|..)> which is illegal. The
1660 most likely cause of this error is that you left out a parenthesis inside
1661 of the C<....> part.
1663 The <-- HERE shows whereabouts in the regular expression the problem was
1666 =item %s defines neither package nor VERSION--version check failed
1668 (F) You said something like "use Module 42" but in the Module file
1669 there are neither package declarations nor a C<$VERSION>.
1671 =item delete argument is index/value array slice, use array slice
1673 (F) You used index/value array slice syntax (C<%array[...]>) as
1674 the argument to C<delete>. You probably meant C<@array[...]> with
1675 an @ symbol instead.
1677 =item delete argument is key/value hash slice, use hash slice
1679 (F) You used key/value hash slice syntax (C<%hash{...}>) as the argument to
1680 C<delete>. You probably meant C<@hash{...}> with an @ symbol instead.
1682 =item delete argument is not a HASH or ARRAY element or slice
1684 (F) The argument to C<delete> must be either a hash or array element,
1690 or a hash or array slice, such as:
1692 @foo[$bar, $baz, $xyzzy]
1693 @{$ref->[12]}{"susie", "queue"}
1695 =item Delimiter for here document is too long
1697 (F) In a here document construct like C<<<FOO>, the label C<FOO> is too
1698 long for Perl to handle. You have to be seriously twisted to write code
1699 that triggers this error.
1701 =item Deprecated use of my() in false conditional
1703 (D deprecated) You used a declaration similar to C<my $x if 0>. There
1704 has been a long-standing bug in Perl that causes a lexical variable
1705 not to be cleared at scope exit when its declaration includes a false
1706 conditional. Some people have exploited this bug to achieve a kind of
1707 static variable. Since we intend to fix this bug, we don't want people
1708 relying on this behavior. You can achieve a similar static effect by
1709 declaring the variable in a separate block outside the function, eg
1711 sub f { my $x if 0; return $x++ }
1715 { my $x; sub f { return $x++ } }
1717 Beginning with perl 5.9.4, you can also use C<state> variables to have
1718 lexicals that are initialized only once (see L<feature>):
1720 sub f { state $x; return $x++ }
1722 =item DESTROY created new reference to dead object '%s'
1724 (F) A DESTROY() method created a new reference to the object which is
1725 just being DESTROYed. Perl is confused, and prefers to abort rather
1726 than to create a dangling reference.
1728 =item Did not produce a valid header
1732 =item %s did not return a true value
1734 (F) A required (or used) file must return a true value to indicate that
1735 it compiled correctly and ran its initialization code correctly. It's
1736 traditional to end such a file with a "1;", though any true value would
1737 do. See L<perlfunc/require>.
1739 =item (Did you mean &%s instead?)
1741 (W misc) You probably referred to an imported subroutine &FOO as $FOO or
1744 =item (Did you mean "local" instead of "our"?)
1746 (W misc) Remember that "our" does not localize the declared global
1747 variable. You have declared it again in the same lexical scope, which
1750 =item (Did you mean $ or @ instead of %?)
1752 (W) You probably said %hash{$key} when you meant $hash{$key} or
1753 @hash{@keys}. On the other hand, maybe you just meant %hash and got
1758 (F) You passed die() an empty string (the equivalent of C<die "">) or
1759 you called it with no args and C<$@> was empty.
1761 =item Document contains no data
1765 =item %s does not define %s::VERSION--version check failed
1767 (F) You said something like "use Module 42" but the Module did not
1768 define a C<$VERSION>.
1770 =item '/' does not take a repeat count
1772 (F) You cannot put a repeat count of any kind right after the '/' code.
1773 See L<perlfunc/pack>.
1775 =item Don't know how to handle magic of type \%o
1777 (P) The internal handling of magical variables has been cursed.
1779 =item do_study: out of memory
1781 (P) This should have been caught by safemalloc() instead.
1783 =item (Do you need to predeclare %s?)
1785 (S syntax) This is an educated guess made in conjunction with the message
1786 "%s found where operator expected". It often means a subroutine or module
1787 name is being referenced that hasn't been declared yet. This may be
1788 because of ordering problems in your file, or because of a missing
1789 "sub", "package", "require", or "use" statement. If you're referencing
1790 something that isn't defined yet, you don't actually have to define the
1791 subroutine or package before the current location. You can use an empty
1792 "sub foo;" or "package FOO;" to enter a "forward" declaration.
1794 =item dump() better written as CORE::dump()
1796 (W misc) You used the obsolescent C<dump()> built-in function, without fully
1797 qualifying it as C<CORE::dump()>. Maybe it's a typo. See L<perlfunc/dump>.
1799 =item dump is not supported
1801 (F) Your machine doesn't support dump/undump.
1803 =item Duplicate free() ignored
1805 (S malloc) An internal routine called free() on something that had
1808 =item Duplicate modifier '%c' after '%c' in %s
1810 (W unpack) You have applied the same modifier more than once after a
1811 type in a pack template. See L<perlfunc/pack>.
1813 =item elseif should be elsif
1815 (S syntax) There is no keyword "elseif" in Perl because Larry thinks
1816 it's ugly. Your code will be interpreted as an attempt to call a method
1817 named "elseif" for the class returned by the following block. This is
1818 unlikely to be what you want.
1820 =item Empty \%c{} in regex; marked by <-- HERE in m/%s/
1822 (F) C<\p> and C<\P> are used to introduce a named Unicode property, as
1823 described in L<perlunicode> and L<perlre>. You used C<\p> or C<\P> in
1824 a regular expression without specifying the property name.
1826 =item entering effective %s failed
1828 (F) While under the C<use filetest> pragma, switching the real and
1829 effective uids or gids failed.
1831 =item %ENV is aliased to %s
1833 (F) You're running under taint mode, and the C<%ENV> variable has been
1834 aliased to another hash, so it doesn't reflect anymore the state of the
1835 program's environment. This is potentially insecure.
1837 =item Error converting file specification %s
1839 (F) An error peculiar to VMS. Because Perl may have to deal with file
1840 specifications in either VMS or Unix syntax, it converts them to a
1841 single form when it must operate on them directly. Either you've passed
1842 an invalid file specification to Perl, or you've found a case the
1843 conversion routines don't handle. Drat.
1845 =item Escape literal pattern white space under /x
1847 (D deprecated) You compiled a regular expression pattern with C</x> to
1848 ignore white space, and you used, as a literal, one of the characters
1849 that Perl plans to eventually treat as white space. The character must
1850 be escaped somehow, or it will work differently on a future Perl that
1851 does treat it as white space. The easiest way is to insert a backslash
1852 immediately before it, or to enclose it with square brackets. This
1853 change is to bring Perl into conformance with Unicode recommendations.
1854 Here are the five characters that generate this warning:
1856 U+200E LEFT-TO-RIGHT MARK,
1857 U+200F RIGHT-TO-LEFT MARK,
1858 U+2028 LINE SEPARATOR,
1860 U+2029 PARAGRAPH SEPARATOR.
1862 =item Eval-group in insecure regular expression
1864 (F) Perl detected tainted data when trying to compile a regular
1865 expression that contains the C<(?{ ... })> zero-width assertion, which
1866 is unsafe. See L<perlre/(?{ code })>, and L<perlsec>.
1868 =item Eval-group not allowed at runtime, use re 'eval' in regex m/%s/
1870 (F) Perl tried to compile a regular expression containing the
1871 C<(?{ ... })> zero-width assertion at run time, as it would when the
1872 pattern contains interpolated values. Since that is a security risk,
1873 it is not allowed. If you insist, you may still do this by using the
1874 C<re 'eval'> pragma or by explicitly building the pattern from an
1875 interpolated string at run time and using that in an eval(). See
1876 L<perlre/(?{ code })>.
1878 =item Eval-group not allowed, use re 'eval' in regex m/%s/
1880 (F) A regular expression contained the C<(?{ ... })> zero-width
1881 assertion, but that construct is only allowed when the C<use re 'eval'>
1882 pragma is in effect. See L<perlre/(?{ code })>.
1884 =item EVAL without pos change exceeded limit in regex; marked by <-- HERE in
1887 (F) You used a pattern that nested too many EVAL calls without consuming
1888 any text. Restructure the pattern so that text is consumed.
1890 The <-- HERE shows whereabouts in the regular expression the problem was
1893 =item Excessively long <> operator
1895 (F) The contents of a <> operator may not exceed the maximum size of a
1896 Perl identifier. If you're just trying to glob a long list of
1897 filenames, try using the glob() operator, or put the filenames into a
1898 variable and glob that.
1900 =item exec? I'm not *that* kind of operating system
1902 (F) The C<exec> function is not implemented on some systems, e.g., Symbian
1903 OS. See L<perlport>.
1905 =item Execution of %s aborted due to compilation errors.
1907 (F) The final summary message when a Perl compilation fails.
1909 =item exists argument is not a HASH or ARRAY element or a subroutine
1911 (F) The argument to C<exists> must be a hash or array element or a
1912 subroutine with an ampersand, such as:
1918 =item exists argument is not a subroutine name
1920 (F) The argument to C<exists> for C<exists &sub> must be a subroutine name,
1921 and not a subroutine call. C<exists &sub()> will generate this error.
1923 =item Exiting eval via %s
1925 (W exiting) You are exiting an eval by unconventional means, such as a
1926 goto, or a loop control statement.
1928 =item Exiting format via %s
1930 (W exiting) You are exiting a format by unconventional means, such as a
1931 goto, or a loop control statement.
1933 =item Exiting pseudo-block via %s
1935 (W exiting) You are exiting a rather special block construct (like a
1936 sort block or subroutine) by unconventional means, such as a goto, or a
1937 loop control statement. See L<perlfunc/sort>.
1939 =item Exiting subroutine via %s
1941 (W exiting) You are exiting a subroutine by unconventional means, such
1942 as a goto, or a loop control statement.
1944 =item Exiting substitution via %s
1946 (W exiting) You are exiting a substitution by unconventional means, such
1947 as a return, a goto, or a loop control statement.
1949 =item Expecting close bracket in regex; marked by <-- HERE in m/%s/
1951 (F) You wrote something like
1955 to denote a capturing group of the form
1956 L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>,
1957 but omitted the C<")">.
1959 =item Expecting '(?flags:(?[...' in regex; marked by <-- HERE in m/%s/
1961 (F) The C<(?[...])> extended character class regular expression construct
1962 only allows character classes (including character class escapes like
1963 C<\d>), operators, and parentheses. The one exception is C<(?flags:...)>
1964 containing at least one flag and exactly one C<(?[...])> construct.
1965 This allows a regular expression containing just C<(?[...])> to be
1966 interpolated. If you see this error message, then you probably
1967 have some other C<(?...)> construct inside your character class. See
1968 L<perlrecharclass/Extended Bracketed Character Classes>.
1970 =item Experimental "%s" subs not enabled
1972 (F) To use lexical subs, you must first enable them:
1974 no warnings 'experimental::lexical_subs';
1975 use feature 'lexical_subs';
1978 =item Explicit blessing to '' (assuming package main)
1980 (W misc) You are blessing a reference to a zero length string. This has
1981 the effect of blessing the reference into the package main. This is
1982 usually not what you want. Consider providing a default target package,
1983 e.g. bless($ref, $p || 'MyPackage');
1985 =item %s: Expression syntax
1987 (A) You've accidentally run your script through B<csh> instead of Perl.
1988 Check the #! line, or manually feed your script into Perl yourself.
1990 =item %s failed--call queue aborted
1992 (F) An untrapped exception was raised while executing a UNITCHECK,
1993 CHECK, INIT, or END subroutine. Processing of the remainder of the
1994 queue of such routines has been prematurely ended.
1996 =item False [] range "%s" in regex; marked by <-- HERE in m/%s/
1998 (W regexp)(F) A character class range must start and end at a literal
1999 character, not another character class like C<\d> or C<[:alpha:]>. The "-"
2000 in your false range is interpreted as a literal "-". In a C<(?[...])>
2001 construct, this is an error, rather than a warning. Consider quoting
2002 the "-", "\-". The <-- HERE shows whereabouts in the regular expression
2003 the problem was discovered. See L<perlre>.
2005 =item Fatal VMS error (status=%d) at %s, line %d
2007 (P) An error peculiar to VMS. Something untoward happened in a VMS
2008 system service or RTL routine; Perl's exit status should provide more
2009 details. The filename in "at %s" and the line number in "line %d" tell
2010 you which section of the Perl source code is distressed.
2012 =item fcntl is not implemented
2014 (F) Your machine apparently doesn't implement fcntl(). What is this, a
2015 PDP-11 or something?
2017 =item FETCHSIZE returned a negative value
2019 (F) A tied array claimed to have a negative number of elements, which
2022 =item Field too wide in 'u' format in pack
2024 (W pack) Each line in an uuencoded string starts with a length indicator
2025 which can't encode values above 63. So there is no point in asking for
2026 a line length bigger than that. Perl will behave as if you specified
2027 C<u63> as the format.
2029 =item Filehandle %s opened only for input
2031 (W io) You tried to write on a read-only filehandle. If you intended
2032 it to be a read-write filehandle, you needed to open it with "+<" or
2033 "+>" or "+>>" instead of with "<" or nothing. If you intended only to
2034 write the file, use ">" or ">>". See L<perlfunc/open>.
2036 =item Filehandle %s opened only for output
2038 (W io) You tried to read from a filehandle opened only for writing, If
2039 you intended it to be a read/write filehandle, you needed to open it
2040 with "+<" or "+>" or "+>>" instead of with ">". If you intended only to
2041 read from the file, use "<". See L<perlfunc/open>. Another possibility
2042 is that you attempted to open filedescriptor 0 (also known as STDIN) for
2043 output (maybe you closed STDIN earlier?).
2045 =item Filehandle %s reopened as %s only for input
2047 (W io) You opened for reading a filehandle that got the same filehandle id
2048 as STDOUT or STDERR. This occurred because you closed STDOUT or STDERR
2051 =item Filehandle STDIN reopened as %s only for output
2053 (W io) You opened for writing a filehandle that got the same filehandle id
2054 as STDIN. This occurred because you closed STDIN previously.
2056 =item Final $ should be \$ or $name
2058 (F) You must now decide whether the final $ in a string was meant to be
2059 a literal dollar sign, or was meant to introduce a variable name that
2060 happens to be missing. So you have to put either the backslash or the
2063 =item flock() on closed filehandle %s
2065 (W closed) The filehandle you're attempting to flock() got itself closed
2066 some time before now. Check your control flow. flock() operates on
2067 filehandles. Are you attempting to call flock() on a dirhandle by the
2070 =item Format not terminated
2072 (F) A format must be terminated by a line with a solitary dot. Perl got
2073 to the end of your file without finding such a line.
2075 =item Format %s redefined
2077 (W redefine) You redefined a format. To suppress this warning, say
2080 no warnings 'redefine';
2081 eval "format NAME =...";
2084 =item Found = in conditional, should be ==
2094 (or something like that).
2096 =item %s found where operator expected
2098 (S syntax) The Perl lexer knows whether to expect a term or an operator.
2099 If it sees what it knows to be a term when it was expecting to see an
2100 operator, it gives you this warning. Usually it indicates that an
2101 operator or delimiter was omitted, such as a semicolon.
2103 =item gdbm store returned %d, errno %d, key "%s"
2105 (S) A warning from the GDBM_File extension that a store failed.
2107 =item gethostent not implemented
2109 (F) Your C library apparently doesn't implement gethostent(), probably
2110 because if it did, it'd feel morally obligated to return every hostname
2113 =item get%sname() on closed socket %s
2115 (W closed) You tried to get a socket or peer socket name on a closed
2116 socket. Did you forget to check the return value of your socket() call?
2118 =item getpwnam returned invalid UIC %#o for user "%s"
2120 (S) A warning peculiar to VMS. The call to C<sys$getuai> underlying the
2121 C<getpwnam> operator returned an invalid UIC.
2123 =item getsockopt() on closed socket %s
2125 (W closed) You tried to get a socket option on a closed socket. Did you
2126 forget to check the return value of your socket() call? See
2127 L<perlfunc/getsockopt>.
2129 =item given is experimental
2131 (S experimental::smartmatch) C<given> depends on smartmatch, which
2132 is experimental, so its behavior may change or even be removed
2133 in any future release of perl. See the explanation under
2134 L<perlsyn/Experimental Details on given and when>.
2136 =item Global symbol "%s" requires explicit package name
2138 (F) You've said "use strict" or "use strict vars", which indicates
2139 that all variables must either be lexically scoped (using "my" or "state"),
2140 declared beforehand using "our", or explicitly qualified to say
2141 which package the global variable is in (using "::").
2143 =item glob failed (%s)
2145 (S glob) Something went wrong with the external program(s) used
2146 for C<glob> and C<< <*.c> >>. Usually, this means that you supplied a C<glob>
2147 pattern that caused the external program to fail and exit with a
2148 nonzero status. If the message indicates that the abnormal exit
2149 resulted in a coredump, this may also mean that your csh (C shell)
2150 is broken. If so, you should change all of the csh-related variables
2151 in config.sh: If you have tcsh, make the variables refer to it as
2152 if it were csh (e.g. C<full_csh='/usr/bin/tcsh'>); otherwise, make them
2153 all empty (except that C<d_csh> should be C<'undef'>) so that Perl will
2154 think csh is missing. In either case, after editing config.sh, run
2155 C<./Configure -S> and rebuild Perl.
2157 =item Glob not terminated
2159 (F) The lexer saw a left angle bracket in a place where it was expecting
2160 a term, so it's looking for the corresponding right angle bracket, and
2161 not finding it. Chances are you left some needed parentheses out
2162 earlier in the line, and you really meant a "less than".
2164 =item gmtime(%f) too large
2166 (W overflow) You called C<gmtime> with a number that was larger than
2167 it can reliably handle and C<gmtime> probably returned the wrong
2168 date. This warning is also triggered with NaN (the special
2169 not-a-number value).
2171 =item gmtime(%f) too small
2173 (W overflow) You called C<gmtime> with a number that was smaller than
2174 it can reliably handle and C<gmtime> probably returned the wrong date.
2176 =item Got an error from DosAllocMem
2178 (P) An error peculiar to OS/2. Most probably you're using an obsolete
2179 version of Perl, and this should not happen anyway.
2181 =item goto must have label
2183 (F) Unlike with "next" or "last", you're not allowed to goto an
2184 unspecified destination. See L<perlfunc/goto>.
2186 =item Goto undefined subroutine%s
2188 (F) You tried to call a subroutine with C<goto &sub> syntax, but
2189 the indicated subroutine hasn't been defined, or if it was, it
2190 has since been undefined.
2192 =item Group name must start with a non-digit word character in regex; marked by
2195 (F) Group names must follow the rules for perl identifiers, meaning
2196 they must start with a non-digit word character. A common cause of
2197 this error is using (?&0) instead of (?0). See L<perlre>.
2199 =item ()-group starts with a count
2201 (F) A ()-group started with a count. A count is supposed to follow
2202 something: a template character or a ()-group. See L<perlfunc/pack>.
2204 =item %s had compilation errors.
2206 (F) The final summary message when a C<perl -c> fails.
2208 =item Had to create %s unexpectedly
2210 (S internal) A routine asked for a symbol from a symbol table that ought
2211 to have existed already, but for some reason it didn't, and had to be
2212 created on an emergency basis to prevent a core dump.
2214 =item Hash %%s missing the % in argument %d of %s()
2216 (D deprecated) Really old Perl let you omit the % on hash names in some
2217 spots. This is now heavily deprecated.
2219 =item %s has too many errors
2221 (F) The parser has given up trying to parse the program after 10 errors.
2222 Further error messages would likely be uninformative.
2224 =item Hexadecimal number > 0xffffffff non-portable
2226 (W portable) The hexadecimal number you specified is larger than 2**32-1
2227 (4294967295) and therefore non-portable between systems. See
2228 L<perlport> for more on portability concerns.
2230 =item Identifier too long
2232 (F) Perl limits identifiers (names for variables, functions, etc.) to
2233 about 250 characters for simple names, and somewhat more for compound
2234 names (like C<$A::B>). You've exceeded Perl's limits. Future versions
2235 of Perl are likely to eliminate these arbitrary limitations.
2237 =item Ignoring zero length \N{} in character class in regex; marked by <-- HERE in m/%s/
2239 (W regexp) Named Unicode character escapes C<(\N{...})> may return a
2240 zero-length sequence. When such an escape is used in a character class
2241 its behaviour is not well defined. Check that the correct escape has
2242 been used, and the correct charname handler is in scope.
2244 =item Illegal binary digit %s
2246 (F) You used a digit other than 0 or 1 in a binary number.
2248 =item Illegal binary digit %s ignored
2250 (W digit) You may have tried to use a digit other than 0 or 1 in a
2251 binary number. Interpretation of the binary number stopped before the
2254 =item Illegal character after '_' in prototype for %s : %s
2256 (W illegalproto) An illegal character was found in a prototype
2257 declaration. The '_' in a prototype must be followed by a ';',
2258 indicating the rest of the parameters are optional, or one of '@'
2259 or '%', since those two will accept 0 or more final parameters.
2261 =item Illegal character \%o (carriage return)
2263 (F) Perl normally treats carriage returns in the program text as it
2264 would any other whitespace, which means you should never see this error
2265 when Perl was built using standard options. For some reason, your
2266 version of Perl appears to have been built without this support. Talk
2267 to your Perl administrator.
2269 =item Illegal character in prototype for %s : %s
2271 (W illegalproto) An illegal character was found in a prototype declaration.
2272 Legal characters in prototypes are $, @, %, *, ;, [, ], &, \, and +.
2274 =item Illegal declaration of anonymous subroutine
2276 (F) When using the C<sub> keyword to construct an anonymous subroutine,
2277 you must always specify a block of code. See L<perlsub>.
2279 =item Illegal declaration of subroutine %s
2281 (F) A subroutine was not declared correctly. See L<perlsub>.
2283 =item Illegal division by zero
2285 (F) You tried to divide a number by 0. Either something was wrong in
2286 your logic, or you need to put a conditional in to guard against
2289 =item Illegal hexadecimal digit %s ignored
2291 (W digit) You may have tried to use a character other than 0 - 9 or
2292 A - F, a - f in a hexadecimal number. Interpretation of the hexadecimal
2293 number stopped before the illegal character.
2295 =item Illegal modulus zero
2297 (F) You tried to divide a number by 0 to get the remainder. Most
2298 numbers don't take to this kindly.
2300 =item Illegal number of bits in vec
2302 (F) The number of bits in vec() (the third argument) must be a power of
2303 two from 1 to 32 (or 64, if your platform supports that).
2305 =item Illegal octal digit %s
2307 (F) You used an 8 or 9 in an octal number.
2309 =item Illegal octal digit %s ignored
2311 (W digit) You may have tried to use an 8 or 9 in an octal number.
2312 Interpretation of the octal number stopped before the 8 or 9.
2314 =item Illegal pattern in regex; marked by <-- HERE in m/%s/
2316 (F) You wrote something like
2320 The C<"+"> is valid only when followed by digits, indicating a
2321 capturing group. See
2322 L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>.
2324 =item Illegal switch in PERL5OPT: -%c
2326 (X) The PERL5OPT environment variable may only be used to set the
2327 following switches: B<-[CDIMUdmtw]>.
2329 =item Ill-formed CRTL environ value "%s"
2331 (W internal) A warning peculiar to VMS. Perl tried to read the CRTL's
2332 internal environ array, and encountered an element without the C<=>
2333 delimiter used to separate keys from values. The element is ignored.
2335 =item Ill-formed message in prime_env_iter: |%s|
2337 (W internal) A warning peculiar to VMS. Perl tried to read a logical
2338 name or CLI symbol definition when preparing to iterate over %ENV, and
2339 didn't see the expected delimiter between key and value, so the line was
2342 =item (in cleanup) %s
2344 (W misc) This prefix usually indicates that a DESTROY() method raised
2345 the indicated exception. Since destructors are usually called by the
2346 system at arbitrary points during execution, and often a vast number of
2347 times, the warning is issued only once for any number of failures that
2348 would otherwise result in the same message being repeated.
2350 Failure of user callbacks dispatched using the C<G_KEEPERR> flag could
2351 also result in this warning. See L<perlcall/G_KEEPERR>.
2353 =item Incomplete expression within '(?[ ])' in regex; marked by <-- HERE in m/%s/
2355 (F) There was a syntax error within the C<(?[ ])>. This can happen if the
2356 expression inside the construct was completely empty, or if there are
2357 too many or few operands for the number of operators. Perl is not smart
2358 enough to give you a more precise indication as to what is wrong.
2360 =item Inconsistent hierarchy during C3 merge of class '%s': merging failed on
2363 (F) The method resolution order (MRO) of the given class is not
2364 C3-consistent, and you have enabled the C3 MRO for this class. See the C3
2365 documentation in L<mro> for more information.
2367 =item In EBCDIC the v-string components cannot exceed 2147483647
2369 (F) An error peculiar to EBCDIC. Internally, v-strings are stored as
2370 Unicode code points, and encoded in EBCDIC as UTF-EBCDIC. The UTF-EBCDIC
2371 encoding is limited to code points no larger than 2147483647 (0x7FFFFFFF).
2373 =item Infinite recursion in regex
2375 (F) You used a pattern that references itself without consuming any input
2376 text. You should check the pattern to ensure that recursive patterns
2377 either consume text or fail.
2379 =item Initialization of state variables in list context currently forbidden
2381 (F) Currently the implementation of "state" only permits the
2382 initialization of scalar variables in scalar context. Re-write
2383 C<state ($a) = 42> as C<state $a = 42> to change from list to scalar
2384 context. Constructions such as C<state (@a) = foo()> will be
2385 supported in a future perl release.
2387 =item Insecure dependency in %s
2389 (F) You tried to do something that the tainting mechanism didn't like.
2390 The tainting mechanism is turned on when you're running setuid or
2391 setgid, or when you specify B<-T> to turn it on explicitly. The
2392 tainting mechanism labels all data that's derived directly or indirectly
2393 from the user, who is considered to be unworthy of your trust. If any
2394 such data is used in a "dangerous" operation, you get this error. See
2395 L<perlsec> for more information.
2397 =item Insecure directory in %s
2399 (F) You can't use system(), exec(), or a piped open in a setuid or
2400 setgid script if C<$ENV{PATH}> contains a directory that is writable by
2401 the world. Also, the PATH must not contain any relative directory.
2404 =item Insecure $ENV{%s} while running %s
2406 (F) You can't use system(), exec(), or a piped open in a setuid or
2407 setgid script if any of C<$ENV{PATH}>, C<$ENV{IFS}>, C<$ENV{CDPATH}>,
2408 C<$ENV{ENV}>, C<$ENV{BASH_ENV}> or C<$ENV{TERM}> are derived from data
2409 supplied (or potentially supplied) by the user. The script must set
2410 the path to a known value, using trustworthy data. See L<perlsec>.
2412 =item Insecure user-defined property %s
2414 (F) Perl detected tainted data when trying to compile a regular
2415 expression that contains a call to a user-defined character property
2416 function, i.e. C<\p{IsFoo}> or C<\p{InFoo}>.
2417 See L<perlunicode/User-Defined Character Properties> and L<perlsec>.
2419 =item In '(?...)', splitting the initial '(?' is deprecated in regex; marked by <-- HERE in m/%s/
2421 (D regexp, deprecated) The two-character sequence C<"(?"> in
2422 this context in a regular expression pattern should be an
2423 indivisible token, with nothing intervening between the C<"(">
2424 and the C<"?">, but you separated them. Due to an accident of
2425 implementation, this prohibition was not enforced, but we do
2426 plan to forbid it in a future Perl version. This message
2427 serves as giving you fair warning of this pending change.
2429 =item Integer overflow in format string for %s
2431 (F) The indexes and widths specified in the format string of C<printf()>
2432 or C<sprintf()> are too large. The numbers must not overflow the size of
2433 integers for your architecture.
2435 =item Integer overflow in %s number
2437 (S overflow) The hexadecimal, octal or binary number you have specified
2438 either as a literal or as an argument to hex() or oct() is too big for
2439 your architecture, and has been converted to a floating point number.
2440 On a 32-bit architecture the largest hexadecimal, octal or binary number
2441 representable without overflow is 0xFFFFFFFF, 037777777777, or
2442 0b11111111111111111111111111111111 respectively. Note that Perl
2443 transparently promotes all numbers to a floating point representation
2444 internally--subject to loss of precision errors in subsequent
2447 =item Integer overflow in srand
2449 (S overflow) The number you have passed to srand is too big to fit
2450 in your architecture's integer representation. The number has been
2451 replaced with the largest integer supported (0xFFFFFFFF on 32-bit
2452 architectures). This means you may be getting less randomness than
2453 you expect, because different random seeds above the maximum will
2454 return the same sequence of random numbers.
2456 =item Integer overflow in version
2458 =item Integer overflow in version %d
2460 (W overflow) Some portion of a version initialization is too large for
2461 the size of integers for your architecture. This is not a warning
2462 because there is no rational reason for a version to try and use an
2463 element larger than typically 2**32. This is usually caused by trying
2464 to use some odd mathematical operation as a version, like 100/9.
2466 =item Internal disaster in regex; marked by <-- HERE in m/%s/
2468 (P) Something went badly wrong in the regular expression parser.
2469 The <-- HERE shows whereabouts in the regular expression the problem was
2472 =item Internal inconsistency in tracking vforks
2474 (S) A warning peculiar to VMS. Perl keeps track of the number of times
2475 you've called C<fork> and C<exec>, to determine whether the current call
2476 to C<exec> should affect the current script or a subprocess (see
2477 L<perlvms/"exec LIST">). Somehow, this count has become scrambled, so
2478 Perl is making a guess and treating this C<exec> as a request to
2479 terminate the Perl script and execute the specified command.
2481 =item internal %<num>p might conflict with future printf extensions
2483 (S internal) Perl's internal routine that handles C<printf> and C<sprintf>
2484 formatting follows a slightly different set of rules when called from
2485 C or XS code. Specifically, formats consisting of digits followed
2486 by "p" (e.g., "%7p") are reserved for future use. If you see this
2487 message, then an XS module tried to call that routine with one such
2490 =item Internal urp in regex; marked by <-- HERE in m/%s/
2492 (P) Something went badly awry in the regular expression parser. The
2493 <-- HERE shows whereabouts in the regular expression the problem was
2496 =item %s (...) interpreted as function
2498 (W syntax) You've run afoul of the rule that says that any list operator
2499 followed by parentheses turns into a function, with all the list
2500 operators arguments found inside the parentheses. See
2501 L<perlop/Terms and List Operators (Leftward)>.
2503 =item Invalid %s attribute: %s
2505 (F) The indicated attribute for a subroutine or variable was not recognized
2506 by Perl or by a user-supplied handler. See L<attributes>.
2508 =item Invalid %s attributes: %s
2510 (F) The indicated attributes for a subroutine or variable were not
2511 recognized by Perl or by a user-supplied handler. See L<attributes>.
2513 =item Invalid character in charnames alias definition; marked by <-- HERE in '%s
2515 (F) You tried to create a custom alias for a character name, with
2516 the C<:alias> option to C<use charnames> and the specified character in
2517 the indicated name isn't valid. See L<charnames/CUSTOM ALIASES>.
2519 =item Invalid \0 character in %s for %s: %s\0%s
2521 (W syscalls) Embedded \0 characters in pathnames or other system call
2522 arguments produce a warning as of 5.20. The parts after the \0 were
2523 formerly ignored by system calls.
2525 =item Invalid character in \N{...}; marked by <-- HERE in \N{%s}
2527 (F) Only certain characters are valid for character names. The
2528 indicated one isn't. See L<charnames/CUSTOM ALIASES>.
2530 =item Invalid conversion in %s: "%s"
2532 (W printf) Perl does not understand the given format conversion. See
2533 L<perlfunc/sprintf>.
2535 =item Invalid escape in the specified encoding in regex; marked by <-- HERE in
2538 (W regexp) The numeric escape (for example C<\xHH>) of value < 256
2539 didn't correspond to a single character through the conversion
2540 from the encoding specified by the encoding pragma.
2541 The escape was replaced with REPLACEMENT CHARACTER (U+FFFD) instead.
2542 The <-- HERE shows whereabouts in the regular expression the
2543 escape was discovered.
2545 =item Invalid hexadecimal number in \N{U+...}
2547 =item Invalid hexadecimal number in \N{U+...} in regex; marked by <-- HERE in
2550 (F) The character constant represented by C<...> is not a valid hexadecimal
2551 number. Either it is empty, or you tried to use a character other than
2552 0 - 9 or A - F, a - f in a hexadecimal number.
2554 =item Invalid module name %s with -%c option: contains single ':'
2556 (F) The module argument to perl's B<-m> and B<-M> command-line options
2557 cannot contain single colons in the module name, but only in the
2558 arguments after "=". In other words, B<-MFoo::Bar=:baz> is ok, but
2559 B<-MFoo:Bar=baz> is not.
2561 =item Invalid mro name: '%s'
2563 (F) You tried to C<mro::set_mro("classname", "foo")> or C<use mro 'foo'>,
2564 where C<foo> is not a valid method resolution order (MRO). Currently,
2565 the only valid ones supported are C<dfs> and C<c3>, unless you have loaded
2566 a module that is a MRO plugin. See L<mro> and L<perlmroapi>.
2568 =item Invalid negative number (%s) in chr
2570 (W utf8) You passed a negative number to C<chr>. Negative numbers are
2571 not valid characters numbers, so it return the Unicode replacement
2574 =item invalid option -D%c, use -D'' to see choices
2576 (S debugging) Perl was called with invalid debugger flags. Call perl
2577 with the B<-D> option with no flags to see the list of acceptable values.
2578 See also L<perlrun/-Dletters>.
2580 =item Invalid [] range "%s" in regex; marked by <-- HERE in m/%s/
2582 (F) The range specified in a character class had a minimum character
2583 greater than the maximum character. One possibility is that you forgot the
2584 C<{}> from your ending C<\x{}> - C<\x> without the curly braces can go only
2585 up to C<ff>. The <-- HERE shows whereabouts in the regular expression the
2586 problem was discovered. See L<perlre>.
2588 =item Invalid range "%s" in transliteration operator
2590 (F) The range specified in the tr/// or y/// operator had a minimum
2591 character greater than the maximum character. See L<perlop>.
2593 =item Invalid separator character %s in attribute list
2595 (F) Something other than a colon or whitespace was seen between the
2596 elements of an attribute list. If the previous attribute had a
2597 parenthesised parameter list, perhaps that list was terminated too soon.
2600 =item Invalid separator character %s in PerlIO layer specification %s
2602 (W layer) When pushing layers onto the Perl I/O system, something other
2603 than a colon or whitespace was seen between the elements of a layer list.
2604 If the previous attribute had a parenthesised parameter list, perhaps that
2605 list was terminated too soon.
2607 =item Invalid strict version format (%s)
2609 (F) A version number did not meet the "strict" criteria for versions.
2610 A "strict" version number is a positive decimal number (integer or
2611 decimal-fraction) without exponentiation or else a dotted-decimal
2612 v-string with a leading 'v' character and at least three components.
2613 The parenthesized text indicates which criteria were not met.
2614 See the L<version> module for more details on allowed version formats.
2616 =item Invalid type '%s' in %s
2618 (F) The given character is not a valid pack or unpack type.
2619 See L<perlfunc/pack>.
2621 (W) The given character is not a valid pack or unpack type but used to be
2624 =item Invalid version format (%s)
2626 (F) A version number did not meet the "lax" criteria for versions.
2627 A "lax" version number is a positive decimal number (integer or
2628 decimal-fraction) without exponentiation or else a dotted-decimal
2629 v-string. If the v-string has fewer than three components, it
2630 must have a leading 'v' character. Otherwise, the leading 'v' is
2631 optional. Both decimal and dotted-decimal versions may have a
2632 trailing "alpha" component separated by an underscore character
2633 after a fractional or dotted-decimal component. The parenthesized
2634 text indicates which criteria were not met. See the L<version> module
2635 for more details on allowed version formats.
2637 =item Invalid version object
2639 (F) The internal structure of the version object was invalid.
2640 Perhaps the internals were modified directly in some way or
2641 an arbitrary reference was blessed into the "version" class.
2643 =item In '(*VERB...)', splitting the initial '(*' is deprecated in regex; marked by <-- HERE in m/%s/
2645 (D regexp, deprecated) The two-character sequence C<"(*"> in
2646 this context in a regular expression pattern should be an
2647 indivisible token, with nothing intervening between the C<"(">
2648 and the C<"*">, but you separated them. Due to an accident of
2649 implementation, this prohibition was not enforced, but we do
2650 plan to forbid it in a future Perl version. This message
2651 serves as giving you fair warning of this pending change.
2653 =item ioctl is not implemented
2655 (F) Your machine apparently doesn't implement ioctl(), which is pretty
2656 strange for a machine that supports C.
2658 =item ioctl() on unopened %s
2660 (W unopened) You tried ioctl() on a filehandle that was never opened.
2661 Check your control flow and number of arguments.
2663 =item IO layers (like '%s') unavailable
2665 (F) Your Perl has not been configured to have PerlIO, and therefore
2666 you cannot use IO layers. To have PerlIO, Perl must be configured
2669 =item IO::Socket::atmark not implemented on this architecture
2671 (F) Your machine doesn't implement the sockatmark() functionality,
2672 neither as a system call nor an ioctl call (SIOCATMARK).
2674 =item $* is no longer supported
2676 (D deprecated, syntax) The special variable C<$*>, deprecated in older
2677 perls, has been removed as of 5.9.0 and is no longer supported. In
2678 previous versions of perl the use of C<$*> enabled or disabled multi-line
2679 matching within a string.
2681 Instead of using C<$*> you should use the C</m> (and maybe C</s>) regexp
2682 modifiers. You can enable C</m> for a lexical scope (even a whole file)
2683 with C<use re '/m'>. (In older versions: when C<$*> was set to a true value
2684 then all regular expressions behaved as if they were written using C</m>.)
2686 =item $# is no longer supported
2688 (D deprecated, syntax) The special variable C<$#>, deprecated in older
2689 perls, has been removed as of 5.9.3 and is no longer supported. You
2690 should use the printf/sprintf functions instead.
2692 =item '%s' is not a code reference
2694 (W overload) The second (fourth, sixth, ...) argument of
2695 overload::constant needs to be a code reference. Either
2696 an anonymous subroutine, or a reference to a subroutine.
2698 =item '%s' is not an overloadable type
2700 (W overload) You tried to overload a constant type the overload package is
2703 =item -i used with no filenames on the command line, reading from STDIN
2705 (S inplace) The C<-i> option was passed on the command line, indicating
2706 that the script is intended to edit files in place, but no files were
2707 given. This is usually a mistake, since editing STDIN in place doesn't
2708 make sense, and can be confusing because it can make perl look like
2709 it is hanging when it is really just trying to read from STDIN. You
2710 should either pass a filename to edit, or remove C<-i> from the command
2711 line. See L<perlrun> for more details.
2713 =item Junk on end of regexp in regex m/%s/
2715 (P) The regular expression parser is confused.
2717 =item Label not found for "last %s"
2719 (F) You named a loop to break out of, but you're not currently in a loop
2720 of that name, not even if you count where you were called from. See
2723 =item Label not found for "next %s"
2725 (F) You named a loop to continue, but you're not currently in a loop of
2726 that name, not even if you count where you were called from. See
2729 =item Label not found for "redo %s"
2731 (F) You named a loop to restart, but you're not currently in a loop of
2732 that name, not even if you count where you were called from. See
2735 =item leaving effective %s failed
2737 (F) While under the C<use filetest> pragma, switching the real and
2738 effective uids or gids failed.
2740 =item length/code after end of string in unpack
2742 (F) While unpacking, the string buffer was already used up when an unpack
2743 length/code combination tried to obtain more data. This results in
2744 an undefined value for the length. See L<perlfunc/pack>.
2746 =item length() used on %s (did you mean "scalar(%s)"?)
2748 (W syntax) You used length() on either an array or a hash when you
2749 probably wanted a count of the items.
2751 Array size can be obtained by doing:
2755 The number of items in a hash can be obtained by doing:
2759 =item Lexing code attempted to stuff non-Latin-1 character into Latin-1 input
2761 (F) An extension is attempting to insert text into the current parse
2762 (using L<lex_stuff_pvn|perlapi/lex_stuff_pvn> or similar), but tried to insert a character that
2763 couldn't be part of the current input. This is an inherent pitfall
2764 of the stuffing mechanism, and one of the reasons to avoid it. Where
2765 it is necessary to stuff, stuffing only plain ASCII is recommended.
2767 =item Lexing code internal error (%s)
2769 (F) Lexing code supplied by an extension violated the lexer's API in a
2772 =item listen() on closed socket %s
2774 (W closed) You tried to do a listen on a closed socket. Did you forget
2775 to check the return value of your socket() call? See
2778 =item List form of piped open not implemented
2780 (F) On some platforms, notably Windows, the three-or-more-arguments
2781 form of C<open> does not support pipes, such as C<open($pipe, '|-', @args)>.
2782 Use the two-argument C<open($pipe, '|prog arg1 arg2...')> form instead.
2784 =item localtime(%f) too large
2786 (W overflow) You called C<localtime> with a number that was larger
2787 than it can reliably handle and C<localtime> probably returned the
2788 wrong date. This warning is also triggered with NaN (the special
2789 not-a-number value).
2791 =item localtime(%f) too small
2793 (W overflow) You called C<localtime> with a number that was smaller
2794 than it can reliably handle and C<localtime> probably returned the
2797 =item Lookbehind longer than %d not implemented in regex m/%s/
2799 (F) There is currently a limit on the length of string which lookbehind can
2800 handle. This restriction may be eased in a future release.
2802 =item Lost precision when %s %f by 1
2804 (W imprecision) The value you attempted to increment or decrement by one
2805 is too large for the underlying floating point representation to store
2806 accurately, hence the target of C<++> or C<--> is unchanged. Perl issues this
2807 warning because it has already switched from integers to floating point
2808 when values are too large for integers, and now even floating point is
2809 insufficient. You may wish to switch to using L<Math::BigInt> explicitly.
2811 =item lstat() on filehandle%s
2813 (W io) You tried to do an lstat on a filehandle. What did you mean
2814 by that? lstat() makes sense only on filenames. (Perl did a fstat()
2815 instead on the filehandle.)
2817 =item lvalue attribute %s already-defined subroutine
2819 (W misc) Although L<attributes.pm|attributes> allows this, turning the lvalue
2820 attribute on or off on a Perl subroutine that is already defined
2821 does not always work properly. It may or may not do what you
2822 want, depending on what code is inside the subroutine, with exact
2823 details subject to change between Perl versions. Only do this
2824 if you really know what you are doing.
2826 =item lvalue attribute ignored after the subroutine has been defined
2828 (W misc) Using the C<:lvalue> declarative syntax to make a Perl
2829 subroutine an lvalue subroutine after it has been defined is
2830 not permitted. To make the subroutine an lvalue subroutine,
2831 add the lvalue attribute to the definition, or put the C<sub
2832 foo :lvalue;> declaration before the definition.
2834 See also L<attributes.pm|attributes>.
2836 =item Magical list constants are not supported
2838 (F) You assigned a magical array to a stash element, and then tried
2839 to use the subroutine from the same slot. You are asking Perl to do
2840 something it cannot do, details subject to change between Perl versions.
2842 =item Malformed integer in [] in pack
2844 (F) Between the brackets enclosing a numeric repeat count only digits
2845 are permitted. See L<perlfunc/pack>.
2847 =item Malformed integer in [] in unpack
2849 (F) Between the brackets enclosing a numeric repeat count only digits
2850 are permitted. See L<perlfunc/pack>.
2852 =item Malformed PERLLIB_PREFIX
2854 (F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form
2861 with nonempty prefix1 and prefix2. If C<prefix1> is indeed a prefix of
2862 a builtin library search path, prefix2 is substituted. The error may
2863 appear if components are not found, or are too long. See
2864 "PERLLIB_PREFIX" in L<perlos2>.
2866 =item Malformed prototype for %s: %s
2868 (F) You tried to use a function with a malformed prototype. The
2869 syntax of function prototypes is given a brief compile-time check for
2870 obvious errors like invalid characters. A more rigorous check is run
2871 when the function is called.
2873 =item Malformed UTF-8 character (%s)
2875 (S utf8)(F) Perl detected a string that didn't comply with UTF-8
2876 encoding rules, even though it had the UTF8 flag on.
2878 One possible cause is that you set the UTF8 flag yourself for data that
2879 you thought to be in UTF-8 but it wasn't (it was for example legacy
2880 8-bit data). To guard against this, you can use Encode::decode_utf8.
2882 If you use the C<:encoding(UTF-8)> PerlIO layer for input, invalid byte
2883 sequences are handled gracefully, but if you use C<:utf8>, the flag is
2884 set without validating the data, possibly resulting in this error
2887 See also L<Encode/"Handling Malformed Data">.
2889 =item Malformed UTF-8 character immediately after '%s'
2891 (F) You said C<use utf8>, but the program file doesn't comply with UTF-8
2892 encoding rules. The message prints out the properly encoded characters
2893 just before the first bad one. If C<utf8> warnings are enabled, a
2894 warning is generated that gives more details about the type of
2897 =item Malformed UTF-8 returned by \N{%s} immediately after '%s'
2899 (F) The charnames handler returned malformed UTF-8.
2901 =item Malformed UTF-8 string in '%c' format in unpack
2903 (F) You tried to unpack something that didn't comply with UTF-8 encoding
2904 rules and perl was unable to guess how to make more progress.
2906 =item Malformed UTF-8 string in pack
2908 (F) You tried to pack something that didn't comply with UTF-8 encoding
2909 rules and perl was unable to guess how to make more progress.
2911 =item Malformed UTF-8 string in unpack
2913 (F) You tried to unpack something that didn't comply with UTF-8 encoding
2914 rules and perl was unable to guess how to make more progress.
2916 =item Malformed UTF-16 surrogate
2918 (F) Perl thought it was reading UTF-16 encoded character data but while
2919 doing it Perl met a malformed Unicode surrogate.
2921 =item %s matches null string many times in regex; marked by <-- HERE in m/%s/
2923 (W regexp) The pattern you've specified would be an infinite loop if the
2924 regular expression engine didn't specifically check for that. The <-- HERE
2925 shows whereabouts in the regular expression the problem was discovered.
2928 =item Maximal count of pending signals (%u) exceeded
2930 (F) Perl aborted due to too high a number of signals pending. This
2931 usually indicates that your operating system tried to deliver signals
2932 too fast (with a very high priority), starving the perl process from
2933 resources it would need to reach a point where it can process signals
2934 safely. (See L<perlipc/"Deferred Signals (Safe Signals)">.)
2936 =item "%s" may clash with future reserved word
2938 (W) This warning may be due to running a perl5 script through a perl4
2939 interpreter, especially if the word that is being warned about is
2942 =item '%' may not be used in pack
2944 (F) You can't pack a string by supplying a checksum, because the
2945 checksumming process loses information, and you can't go the other way.
2946 See L<perlfunc/unpack>.
2948 =item Method for operation %s not found in package %s during blessing
2950 (F) An attempt was made to specify an entry in an overloading table that
2951 doesn't resolve to a valid subroutine. See L<overload>.
2953 =item Method %s not permitted
2957 =item Might be a runaway multi-line %s string starting on line %d
2959 (S) An advisory indicating that the previous error may have been caused
2960 by a missing delimiter on a string or pattern, because it eventually
2961 ended earlier on the current line.
2963 =item Misplaced _ in number
2965 (W syntax) An underscore (underbar) in a numeric constant did not
2966 separate two digits.
2968 =item Missing argument in %s
2970 (W uninitialized) A printf-type format required more arguments than were
2973 =item Missing argument to -%c
2975 (F) The argument to the indicated command line switch must follow
2976 immediately after the switch, without intervening spaces.
2978 =item Missing braces on \N{}
2980 =item Missing braces on \N{} in regex; marked by <-- HERE in m/%s/
2982 (F) Wrong syntax of character name literal C<\N{charname}> within
2983 double-quotish context. This can also happen when there is a space
2984 (or comment) between the C<\N> and the C<{> in a regex with the C</x> modifier.
2985 This modifier does not change the requirement that the brace immediately
2988 =item Missing braces on \o{}
2990 (F) A C<\o> must be followed immediately by a C<{> in double-quotish context.
2992 =item Missing comma after first argument to %s function
2994 (F) While certain functions allow you to specify a filehandle or an
2995 "indirect object" before the argument list, this ain't one of them.
2997 =item Missing command in piped open
2999 (W pipe) You used the C<open(FH, "| command")> or
3000 C<open(FH, "command |")> construction, but the command was missing or
3003 =item Missing control char name in \c
3005 (F) A double-quoted string ended with "\c", without the required control
3008 =item Missing name in "%s sub"
3010 (F) The reserved syntax for lexically scoped subroutines requires that
3011 they have a name with which they can be found.
3013 =item Missing $ on loop variable
3015 (F) Apparently you've been programming in B<csh> too much. Variables
3016 are always mentioned with the $ in Perl, unlike in the shells, where it
3017 can vary from one line to the next.
3019 =item Missing ']' in prototype for %s : %s
3021 (W illegalproto) A grouping was started with C<[> but never closed with
3024 =item (Missing operator before %s?)
3026 (S syntax) This is an educated guess made in conjunction with the message
3027 "%s found where operator expected". Often the missing operator is a comma.
3029 =item Missing right brace on \%c{} in regex; marked by <-- HERE in m/%s/
3031 (F) Missing right brace in C<\x{...}>, C<\p{...}>, C<\P{...}>, or C<\N{...}>.
3033 =item Missing right brace on \N{} or unescaped left brace after \N
3035 (F) C<\N> has two meanings.
3037 The traditional one has it followed by a name enclosed in braces,
3038 meaning the character (or sequence of characters) given by that
3039 name. Thus C<\N{ASTERISK}> is another way of writing C<*>, valid in both
3040 double-quoted strings and regular expression patterns. In patterns,
3041 it doesn't have the meaning an unescaped C<*> does.
3043 Starting in Perl 5.12.0, C<\N> also can have an additional meaning (only)
3044 in patterns, namely to match a non-newline character. (This is short
3045 for C<[^\n]>, and like C<.> but is not affected by the C</s> regex modifier.)
3047 This can lead to some ambiguities. When C<\N> is not followed immediately
3048 by a left brace, Perl assumes the C<[^\n]> meaning. Also, if the braces
3049 form a valid quantifier such as C<\N{3}> or C<\N{5,}>, Perl assumes that this
3050 means to match the given quantity of non-newlines (in these examples,
3051 3; and 5 or more, respectively). In all other case, where there is a
3052 C<\N{> and a matching C<}>, Perl assumes that a character name is desired.
3054 However, if there is no matching C<}>, Perl doesn't know if it was
3055 mistakenly omitted, or if C<[^\n]{> was desired, and raises this error.
3056 If you meant the former, add the right brace; if you meant the latter,
3057 escape the brace with a backslash, like so: C<\N\{>
3059 =item Missing right curly or square bracket
3061 (F) The lexer counted more opening curly or square brackets than closing
3062 ones. As a general rule, you'll find it's missing near the place you
3065 =item (Missing semicolon on previous line?)
3067 (S syntax) This is an educated guess made in conjunction with the message
3068 "%s found where operator expected". Don't automatically put a semicolon on
3069 the previous line just because you saw this message.
3071 =item Modification of a read-only value attempted
3073 (F) You tried, directly or indirectly, to change the value of a
3074 constant. You didn't, of course, try "2 = 1", because the compiler
3075 catches that. But an easy way to do the same thing is:
3077 sub mod { $_[0] = 1 }
3080 Another way is to assign to a substr() that's off the end of the string.
3082 Yet another way is to assign to a C<foreach> loop I<VAR> when I<VAR>
3083 is aliased to a constant in the look I<LIST>:
3086 foreach my $n ($x, 2) {
3087 $n *= 2; # modifies the $x, but fails on attempt to
3090 =item Modification of non-creatable array value attempted, %s
3092 (F) You tried to make an array value spring into existence, and the
3093 subscript was probably negative, even counting from end of the array
3096 =item Modification of non-creatable hash value attempted, %s
3098 (P) You tried to make a hash value spring into existence, and it
3099 couldn't be created for some peculiar reason.
3101 =item Module name must be constant
3103 (F) Only a bare module name is allowed as the first argument to a "use".
3105 =item Module name required with -%c option
3107 (F) The C<-M> or C<-m> options say that Perl should load some module, but
3108 you omitted the name of the module. Consult L<perlrun> for full details
3109 about C<-M> and C<-m>.
3111 =item More than one argument to '%s' open
3113 (F) The C<open> function has been asked to open multiple files. This
3114 can happen if you are trying to open a pipe to a command that takes a
3115 list of arguments, but have forgotten to specify a piped open mode.
3116 See L<perlfunc/open> for details.
3118 =item mprotect for %p %u failed with %d
3120 =item mprotect RW for %p %u failed with %d
3122 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_OPS (see
3123 L<perlhacktips>), but an op tree could not be made read-only, or a
3124 read-only op tree could not be made mutable before freeing the ops.
3126 =item msg%s not implemented
3128 (F) You don't have System V message IPC on your system.
3130 =item Multidimensional syntax %s not supported
3132 (W syntax) Multidimensional arrays aren't written like C<$foo[1,2,3]>.
3133 They're written like C<$foo[1][2][3]>, as in C.
3135 =item '/' must follow a numeric type in unpack
3137 (F) You had an unpack template that contained a '/', but this did not
3138 follow some unpack specification producing a numeric value.
3139 See L<perlfunc/pack>.
3141 =item "my sub" not yet implemented
3143 (F) Lexically scoped subroutines are not yet implemented. Don't try
3146 =item "my %s" used in sort comparison
3148 (W syntax) The package variables $a and $b are used for sort comparisons.
3149 You used $a or $b in as an operand to the C<< <=> >> or C<cmp> operator inside a
3150 sort comparison block, and the variable had earlier been declared as a
3151 lexical variable. Either qualify the sort variable with the package
3152 name, or rename the lexical variable.
3154 =item "my" variable %s can't be in a package
3156 (F) Lexically scoped variables aren't in a package, so it doesn't make
3157 sense to try to declare one with a package qualifier on the front. Use
3158 local() if you want to localize a package variable.
3160 =item Name "%s::%s" used only once: possible typo
3162 (W once) Typographical errors often show up as unique variable names.
3163 If you had a good reason for having a unique name, then just mention it
3164 again somehow to suppress the message. The C<our> declaration is provided
3167 NOTE: This warning detects symbols that have been used only once so $c, @c,
3168 %c, *c, &c, sub c{}, c(), and c (the filehandle or format) are considered
3169 the same; if a program uses $c only once but also uses any of the others it
3170 will not trigger this warning. Symbols beginning with an underscore and
3171 symbols using special identifiers (q.v. L<perldata>) are exempt from this
3174 =item Need exactly 3 octal digits in regex; marked by <-- HERE in m/%s/
3176 (F) Within S<C<(?[ ])>>, all constants interpreted as octal need to be
3177 exactly 3 digits long. This helps catch some ambiguities. If your
3178 constant is too short, add leading zeros, like
3180 (?[ [ \078 ] ]) # Syntax error!
3181 (?[ [ \0078 ] ]) # Works
3182 (?[ [ \007 8 ] ]) # Clearer
3184 The maximum number this construct can express is C<\777>. If you
3185 need a larger one, you need to use L<\o{}|perlrebackslash/Octal escapes> instead. If you meant
3186 two separate things, you need to separate them:
3188 (?[ [ \7776 ] ]) # Syntax error!
3189 (?[ [ \o{7776} ] ]) # One meaning
3190 (?[ [ \777 6 ] ]) # Another meaning
3191 (?[ [ \777 \006 ] ]) # Still another
3193 =item Negative '/' count in unpack
3195 (F) The length count obtained from a length/code unpack operation was
3196 negative. See L<perlfunc/pack>.
3198 =item Negative length
3200 (F) You tried to do a read/write/send/recv operation with a buffer
3201 length that is less than 0. This is difficult to imagine.
3203 =item Negative offset to vec in lvalue context
3205 (F) When C<vec> is called in an lvalue context, the second argument must be
3206 greater than or equal to zero.
3208 =item Nested quantifiers in regex; marked by <-- HERE in m/%s/
3210 (F) You can't quantify a quantifier without intervening parentheses.
3211 So things like ** or +* or ?* are illegal. The <-- HERE shows
3212 whereabouts in the regular expression the problem was discovered.
3214 Note that the minimal matching quantifiers, C<*?>, C<+?>, and
3215 C<??> appear to be nested quantifiers, but aren't. See L<perlre>.
3217 =item %s never introduced
3219 (S internal) The symbol in question was declared but somehow went out of
3220 scope before it could possibly have been used.
3222 =item next::method/next::can/maybe::next::method cannot find enclosing method
3224 (F) C<next::method> needs to be called within the context of a
3225 real method in a real package, and it could not find such a context.
3228 =item \N in a character class must be a named character: \N{...} in regex;
3229 marked by <-- HERE in m/%s/
3231 (F) The new (5.12) meaning of C<\N> as C<[^\n]> is not valid in
3232 a bracketed character class, for the same reason that C<.> in
3233 a character class loses its specialness: it matches almost
3234 everything, which is probably not what you want.
3236 =item \N{NAME} must be resolved by the lexer in regex; marked by <-- HERE in m/%s/
3238 (F) When compiling a regex pattern, an unresolved named character or
3239 sequence was encountered. This can happen in any of several ways that
3240 bypass the lexer, such as using single-quotish context, or an extra
3241 backslash in double-quotish:
3243 $re = '\N{SPACE}'; # Wrong!
3244 $re = "\\N{SPACE}"; # Wrong!
3247 Instead, use double-quotes with a single backslash:
3249 $re = "\N{SPACE}"; # ok
3252 The lexer can be bypassed as well by creating the pattern from smaller
3256 /${re}{SPACE}/; # Wrong!
3258 It's not a good idea to split a construct in the middle like this, and
3259 it doesn't work here. Instead use the solution above.
3261 Finally, the message also can happen under the C</x> regex modifier when the
3262 C<\N> is separated by spaces from the C<{>, in which case, remove the spaces.
3264 /\N {SPACE}/x; # Wrong!
3267 =item No %s allowed while running setuid
3269 (F) Certain operations are deemed to be too insecure for a setuid or
3270 setgid script to even be allowed to attempt. Generally speaking there
3271 will be another way to do what you want that is, if not secure, at least
3272 securable. See L<perlsec>.
3274 =item No code specified for -%c
3276 (F) Perl's B<-e> and B<-E> command-line options require an argument. If
3277 you want to run an empty program, pass the empty string as a separate
3278 argument or run a program consisting of a single 0 or 1:
3284 =item No comma allowed after %s
3286 (F) A list operator that has a filehandle or "indirect object" is
3287 not allowed to have a comma between that and the following arguments.
3288 Otherwise it'd be just another one of the arguments.
3290 One possible cause for this is that you expected to have imported
3291 a constant to your name space with B<use> or B<import> while no such
3292 importing took place, it may for example be that your operating
3293 system does not support that particular constant. Hopefully you did
3294 use an explicit import list for the constants you expect to see;
3295 please see L<perlfunc/use> and L<perlfunc/import>. While an
3296 explicit import list would probably have caught this error earlier
3297 it naturally does not remedy the fact that your operating system
3298 still does not support that constant. Maybe you have a typo in
3299 the constants of the symbol import list of B<use> or B<import> or in the
3300 constant name at the line where this error was triggered?
3302 =item No command into which to pipe on command line
3304 (F) An error peculiar to VMS. Perl handles its own command line
3305 redirection, and found a '|' at the end of the command line, so it
3306 doesn't know where you want to pipe the output from this command.
3308 =item No DB::DB routine defined
3310 (F) The currently executing code was compiled with the B<-d> switch, but
3311 for some reason the current debugger (e.g. F<perl5db.pl> or a C<Devel::>
3312 module) didn't define a routine to be called at the beginning of each
3315 =item No dbm on this machine
3317 (P) This is counted as an internal error, because every machine should
3318 supply dbm nowadays, because Perl comes with SDBM. See L<SDBM_File>.
3320 =item No DB::sub routine defined
3322 (F) The currently executing code was compiled with the B<-d> switch, but
3323 for some reason the current debugger (e.g. F<perl5db.pl> or a C<Devel::>
3324 module) didn't define a C<DB::sub> routine to be called at the beginning
3325 of each ordinary subroutine call.
3327 =item No directory specified for -I
3329 (F) The B<-I> command-line switch requires a directory name as part of the
3330 I<same> argument. Use B<-Ilib>, for instance. B<-I lib> won't work.
3332 =item No error file after 2> or 2>> on command line
3334 (F) An error peculiar to VMS. Perl handles its own command line
3335 redirection, and found a '2>' or a '2>>' on the command line, but can't
3336 find the name of the file to which to write data destined for stderr.
3338 =item No group ending character '%c' found in template
3340 (F) A pack or unpack template has an opening '(' or '[' without its
3341 matching counterpart. See L<perlfunc/pack>.
3343 =item No input file after < on command line
3345 (F) An error peculiar to VMS. Perl handles its own command line
3346 redirection, and found a '<' on the command line, but can't find the
3347 name of the file from which to read data for stdin.
3349 =item No next::method '%s' found for %s
3351 (F) C<next::method> found no further instances of this method name
3352 in the remaining packages of the MRO of this class. If you don't want
3353 it throwing an exception, use C<maybe::next::method>
3354 or C<next::can>. See L<mro>.
3356 =item Non-hex character in regex; marked by <-- HERE in m/%s/
3358 (F) In a regular expression, there was a non-hexadecimal character where
3359 a hex one was expected, like
3364 =item Non-octal character in regex; marked by <-- HERE in m/%s/
3366 (F) In a regular expression, there was a non-octal character where
3367 an octal one was expected, like
3371 =item Non-octal character '%c'. Resolved as "%s"
3373 (W digit) In parsing an octal numeric constant, a character was
3374 unexpectedly encountered that isn't octal. The resulting value
3377 =item "no" not allowed in expression
3379 (F) The "no" keyword is recognized and executed at compile time, and
3380 returns no useful value. See L<perlmod>.
3382 =item Non-string passed as bitmask
3384 (W misc) A number has been passed as a bitmask argument to select().
3385 Use the vec() function to construct the file descriptor bitmasks for
3386 select. See L<perlfunc/select>.
3388 =item No output file after > on command line
3390 (F) An error peculiar to VMS. Perl handles its own command line
3391 redirection, and found a lone '>' at the end of the command line, so it
3392 doesn't know where you wanted to redirect stdout.
3394 =item No output file after > or >> on command line
3396 (F) An error peculiar to VMS. Perl handles its own command line
3397 redirection, and found a '>' or a '>>' on the command line, but can't
3398 find the name of the file to which to write data destined for stdout.
3400 =item No package name allowed for variable %s in "our"
3402 (F) Fully qualified variable names are not allowed in "our"
3403 declarations, because that doesn't make much sense under existing
3404 semantics. Such syntax is reserved for future extensions.
3406 =item No Perl script found in input
3408 (F) You called C<perl -x>, but no line was found in the file beginning
3409 with #! and containing the word "perl".
3411 =item No setregid available
3413 (F) Configure didn't find anything resembling the setregid() call for
3416 =item No setreuid available
3418 (F) Configure didn't find anything resembling the setreuid() call for
3421 =item No such class %s
3423 (F) You provided a class qualifier in a "my", "our" or "state"
3424 declaration, but this class doesn't exist at this point in your program.
3426 =item No such class field "%s" in variable %s of type %s
3428 (F) You tried to access a key from a hash through the indicated typed
3429 variable but that key is not allowed by the package of the same type.
3430 The indicated package has restricted the set of allowed keys using the
3433 =item No such hook: %s
3435 (F) You specified a signal hook that was not recognized by Perl.
3436 Currently, Perl accepts C<__DIE__> and C<__WARN__> as valid signal hooks.
3438 =item No such pipe open
3440 (P) An error peculiar to VMS. The internal routine my_pclose() tried to
3441 close a pipe which hadn't been opened. This should have been caught
3442 earlier as an attempt to close an unopened filehandle.
3444 =item No such signal: SIG%s
3446 (W signal) You specified a signal name as a subscript to %SIG that was
3447 not recognized. Say C<kill -l> in your shell to see the valid signal
3448 names on your system.
3450 =item Not a CODE reference
3452 (F) Perl was trying to evaluate a reference to a code value (that is, a
3453 subroutine), but found a reference to something else instead. You can
3454 use the ref() function to find out what kind of ref it really was. See
3457 =item Not a GLOB reference
3459 (F) Perl was trying to evaluate a reference to a "typeglob" (that is, a
3460 symbol table entry that looks like C<*foo>), but found a reference to
3461 something else instead. You can use the ref() function to find out what
3462 kind of ref it really was. See L<perlref>.
3464 =item Not a HASH reference
3466 (F) Perl was trying to evaluate a reference to a hash value, but found a
3467 reference to something else instead. You can use the ref() function to
3468 find out what kind of ref it really was. See L<perlref>.
3470 =item Not an ARRAY reference
3472 (F) Perl was trying to evaluate a reference to an array value, but found
3473 a reference to something else instead. You can use the ref() function
3474 to find out what kind of ref it really was. See L<perlref>.
3476 =item Not an unblessed ARRAY reference
3478 (F) You passed a reference to a blessed array to C<push>, C<shift> or
3479 another array function. These only accept unblessed array references
3480 or arrays beginning explicitly with C<@>.
3482 =item Not a SCALAR reference
3484 (F) Perl was trying to evaluate a reference to a scalar value, but found
3485 a reference to something else instead. You can use the ref() function
3486 to find out what kind of ref it really was. See L<perlref>.
3488 =item Not a subroutine reference
3490 (F) Perl was trying to evaluate a reference to a code value (that is, a
3491 subroutine), but found a reference to something else instead. You can
3492 use the ref() function to find out what kind of ref it really was. See
3495 =item Not a subroutine reference in overload table
3497 (F) An attempt was made to specify an entry in an overloading table that
3498 doesn't somehow point to a valid subroutine. See L<overload>.
3500 =item Not enough arguments for %s
3502 (F) The function requires more arguments than you specified.
3504 =item Not enough format arguments
3506 (W syntax) A format specified more picture fields than the next line
3507 supplied. See L<perlform>.
3511 (A) You've accidentally run your script through the Bourne shell instead
3512 of Perl. Check the #! line, or manually feed your script into Perl
3515 =item (?[...]) not valid in locale in regex; marked by <-- HERE in m/%s/
3517 (F) C<(?[...])> cannot be used within the scope of a C<S<use locale>> or with
3518 an C</l> regular expression modifier, as that would require deferring
3519 to run-time the calculation of what it should evaluate to, and it is
3520 regex compile-time only.
3522 =item no UTC offset information; assuming local time is UTC
3524 (S) A warning peculiar to VMS. Perl was unable to find the local
3525 timezone offset, so it's assuming that local system time is equivalent
3526 to UTC. If it's not, define the logical name
3527 F<SYS$TIMEZONE_DIFFERENTIAL> to translate to the number of seconds which
3528 need to be added to UTC to get local time.
3530 =item Null filename used
3532 (F) You can't require the null filename, especially because on many
3533 machines that means the current directory! See L<perlfunc/require>.
3535 =item NULL OP IN RUN
3537 (S debugging) Some internal routine called run() with a null opcode
3540 =item Null picture in formline
3542 (F) The first argument to formline must be a valid format picture
3543 specification. It was found to be empty, which probably means you
3544 supplied it an uninitialized value. See L<perlform>.
3548 (P) An attempt was made to realloc NULL.
3550 =item NULL regexp argument
3552 (P) The internal pattern matching routines blew it big time.
3554 =item NULL regexp parameter
3556 (P) The internal pattern matching routines are out of their gourd.
3558 =item Number too long
3560 (F) Perl limits the representation of decimal numbers in programs to
3561 about 250 characters. You've exceeded that length. Future
3562 versions of Perl are likely to eliminate this arbitrary limitation. In
3563 the meantime, try using scientific notation (e.g. "1e6" instead of
3566 =item Number with no digits
3568 (F) Perl was looking for a number but found nothing that looked like
3569 a number. This happens, for example with C<\o{}>, with no number between
3572 =item Octal number > 037777777777 non-portable
3574 (W portable) The octal number you specified is larger than 2**32-1
3575 (4294967295) and therefore non-portable between systems. See
3576 L<perlport> for more on portability concerns.
3578 =item Odd number of arguments for overload::constant
3580 (W overload) The call to overload::constant contained an odd number of
3581 arguments. The arguments should come in pairs.
3583 =item Odd number of elements in anonymous hash
3585 (W misc) You specified an odd number of elements to initialize a hash,
3586 which is odd, because hashes come in key/value pairs.
3588 =item Odd number of elements in hash assignment
3590 (W misc) You specified an odd number of elements to initialize a hash,
3591 which is odd, because hashes come in key/value pairs.
3593 =item Offset outside string
3595 (F)(W layer) You tried to do a read/write/send/recv/seek operation
3596 with an offset pointing outside the buffer. This is difficult to
3597 imagine. The sole exceptions to this are that zero padding will
3598 take place when going past the end of the string when either
3599 C<sysread()>ing a file, or when seeking past the end of a scalar opened
3600 for I/O (in anticipation of future reads and to imitate the behaviour
3603 =item %s() on unopened %s
3605 (W unopened) An I/O operation was attempted on a filehandle that was
3606 never initialized. You need to do an open(), a sysopen(), or a socket()
3607 call, or call a constructor from the FileHandle package.
3609 =item -%s on unopened filehandle %s
3611 (W unopened) You tried to invoke a file test operator on a filehandle
3612 that isn't open. Check your control flow. See also L<perlfunc/-X>.
3616 (S internal) An internal warning that the grammar is screwed up.
3620 (S internal) An internal warning that the grammar is screwed up.
3622 =item Opening dirhandle %s also as a file
3624 (D io, deprecated) You used open() to associate a filehandle to
3625 a symbol (glob or scalar) that already holds a dirhandle.
3626 Although legal, this idiom might render your code confusing
3629 =item Opening filehandle %s also as a directory
3631 (D io, deprecated) You used opendir() to associate a dirhandle to
3632 a symbol (glob or scalar) that already holds a filehandle.
3633 Although legal, this idiom might render your code confusing
3636 =item Operand with no preceding operator in regex; marked by <-- HERE in m/%s/
3638 (F) You wrote something like
3640 (?[ \p{Digit} \p{Thai} ])
3642 There are two operands, but no operator giving how you want to combine
3645 =item Operation "%s": no method found, %s
3647 (F) An attempt was made to perform an overloaded operation for which no
3648 handler was defined. While some handlers can be autogenerated in terms
3649 of other handlers, there is no default handler for any operation, unless
3650 the C<fallback> overloading key is specified to be true. See L<overload>.
3652 =item Operation "%s" returns its argument for non-Unicode code point 0x%X
3654 (S utf8, non_unicode) You performed an operation requiring Unicode
3655 semantics on a code point that is not in Unicode, so what it should do
3656 is not defined. Perl has chosen to have it do nothing, and warn you.
3658 If the operation shown is "ToFold", it means that case-insensitive
3659 matching in a regular expression was done on the code point.
3661 If you know what you are doing you can turn off this warning by
3662 C<no warnings 'non_unicode';>.
3664 =item Operation "%s" returns its argument for UTF-16 surrogate U+%X
3666 (S utf8, surrogate) You performed an operation requiring Unicode
3667 semantics on a Unicode surrogate. Unicode frowns upon the use of
3668 surrogates for anything but storing strings in UTF-16, but semantics
3669 are (reluctantly) defined for the surrogates, and they are to do
3670 nothing for this operation. Because the use of surrogates can be
3671 dangerous, Perl warns.
3673 If the operation shown is "ToFold", it means that case-insensitive
3674 matching in a regular expression was done on the code point.
3676 If you know what you are doing you can turn off this warning by
3677 C<no warnings 'surrogate';>.
3679 =item Operator or semicolon missing before %s
3681 (S ambiguous) You used a variable or subroutine call where the parser
3682 was expecting an operator. The parser has assumed you really meant to
3683 use an operator, but this is highly likely to be incorrect. For
3684 example, if you say "*foo *foo" it will be interpreted as if you said
3687 =item "our" variable %s redeclared
3689 (W misc) You seem to have already declared the same global once before
3690 in the current lexical scope.
3692 =item Out of memory!
3694 (X) The malloc() function returned 0, indicating there was insufficient
3695 remaining memory (or virtual memory) to satisfy the request. Perl has
3696 no option but to exit immediately.
3698 At least in Unix you may be able to get past this by increasing your
3699 process datasize limits: in csh/tcsh use C<limit> and
3700 C<limit datasize n> (where C<n> is the number of kilobytes) to check
3701 the current limits and change them, and in ksh/bash/zsh use C<ulimit -a>
3702 and C<ulimit -d n>, respectively.
3704 =item Out of memory during %s extend
3706 (X) An attempt was made to extend an array, a list, or a string beyond
3707 the largest possible memory allocation.
3709 =item Out of memory during "large" request for %s
3711 (F) The malloc() function returned 0, indicating there was insufficient
3712 remaining memory (or virtual memory) to satisfy the request. However,
3713 the request was judged large enough (compile-time default is 64K), so a
3714 possibility to shut down by trapping this error is granted.
3716 =item Out of memory during request for %s
3718 (X)(F) The malloc() function returned 0, indicating there was
3719 insufficient remaining memory (or virtual memory) to satisfy the
3722 The request was judged to be small, so the possibility to trap it
3723 depends on the way perl was compiled. By default it is not trappable.
3724 However, if compiled for this, Perl may use the contents of C<$^M> as an
3725 emergency pool after die()ing with this message. In this case the error
3726 is trappable I<once>, and the error message will include the line and file
3727 where the failed request happened.
3729 =item Out of memory during ridiculously large request
3731 (F) You can't allocate more than 2^31+"small amount" bytes. This error
3732 is most likely to be caused by a typo in the Perl program. e.g.,
3733 C<$arr[time]> instead of C<$arr[$time]>.
3735 =item Out of memory for yacc stack
3737 (F) The yacc parser wanted to grow its stack so it could continue
3738 parsing, but realloc() wouldn't give it more memory, virtual or
3741 =item '.' outside of string in pack
3743 (F) The argument to a '.' in your template tried to move the working
3744 position to before the start of the packed string being built.
3746 =item '@' outside of string in unpack
3748 (F) You had a template that specified an absolute position outside
3749 the string being unpacked. See L<perlfunc/pack>.
3751 =item '@' outside of string with malformed UTF-8 in unpack
3753 (F) You had a template that specified an absolute position outside
3754 the string being unpacked. The string being unpacked was also invalid
3755 UTF-8. See L<perlfunc/pack>.
3757 =item overload arg '%s' is invalid
3759 (W overload) The L<overload> pragma was passed an argument it did not
3760 recognize. Did you mistype an operator?
3762 =item Overloaded dereference did not return a reference
3764 (F) An object with an overloaded dereference operator was dereferenced,
3765 but the overloaded operation did not return a reference. See
3768 =item Overloaded qr did not return a REGEXP
3770 (F) An object with a C<qr> overload was used as part of a match, but the
3771 overloaded operation didn't return a compiled regexp. See L<overload>.
3773 =item %s package attribute may clash with future reserved word: %s
3775 (W reserved) A lowercase attribute name was used that had a
3776 package-specific handler. That name might have a meaning to Perl itself
3777 some day, even though it doesn't yet. Perhaps you should use a
3778 mixed-case attribute name, instead. See L<attributes>.
3780 =item pack/unpack repeat count overflow
3782 (F) You can't specify a repeat count so large that it overflows your
3783 signed integers. See L<perlfunc/pack>.
3787 (W io) A single call to write() produced more lines than can fit on a
3788 page. See L<perlform>.
3792 (P) An internal error.
3794 =item panic: attempt to call %s in %s
3796 (P) One of the file test operators entered a code branch that calls
3797 an ACL related-function, but that function is not available on this
3798 platform. Earlier checks mean that it should not be possible to
3799 enter this branch on this platform.
3801 =item panic: child pseudo-process was never scheduled
3803 (P) A child pseudo-process in the ithreads implementation on Windows
3804 was not scheduled within the time period allowed and therefore was not
3805 able to initialize properly.
3807 =item panic: ck_grep, type=%u
3809 (P) Failed an internal consistency check trying to compile a grep.
3811 =item panic: ck_split, type=%u
3813 (P) Failed an internal consistency check trying to compile a split.
3815 =item panic: corrupt saved stack index %ld
3817 (P) The savestack was requested to restore more localized values than
3818 there are in the savestack.
3820 =item panic: del_backref
3822 (P) Failed an internal consistency check while trying to reset a weak
3827 (P) We popped the context stack to an eval context, and then discovered
3828 it wasn't an eval context.
3830 =item panic: do_subst
3832 (P) The internal pp_subst() routine was called with invalid operational
3835 =item panic: do_trans_%s
3837 (P) The internal do_trans routines were called with invalid operational
3840 =item panic: fold_constants JMPENV_PUSH returned %d
3842 (P) While attempting folding constants an exception other than an C<eval>
3847 (P) The library function frexp() failed, making printf("%f") impossible.
3849 =item panic: goto, type=%u, ix=%ld
3851 (P) We popped the context stack to a context with the specified label,
3852 and then discovered it wasn't a context we know how to do a goto in.
3854 =item panic: gp_free failed to free glob pointer
3856 (P) The internal routine used to clear a typeglob's entries tried
3857 repeatedly, but each time something re-created entries in the glob.
3858 Most likely the glob contains an object with a reference back to
3859 the glob and a destructor that adds a new object to the glob.
3861 =item panic: INTERPCASEMOD, %s
3863 (P) The lexer got into a bad state at a case modifier.
3865 =item panic: INTERPCONCAT, %s
3867 (P) The lexer got into a bad state parsing a string with brackets.
3869 =item panic: kid popen errno read
3871 (F) forked child returned an incomprehensible message about its errno.
3873 =item panic: last, type=%u
3875 (P) We popped the context stack to a block context, and then discovered
3876 it wasn't a block context.
3878 =item panic: leave_scope clearsv
3880 (P) A writable lexical variable became read-only somehow within the
3883 =item panic: leave_scope inconsistency %u
3885 (P) The savestack probably got out of sync. At least, there was an
3886 invalid enum on the top of it.
3888 =item panic: magic_killbackrefs
3890 (P) Failed an internal consistency check while trying to reset all weak
3891 references to an object.
3893 =item panic: malloc, %s
3895 (P) Something requested a negative number of bytes of malloc.
3897 =item panic: memory wrap
3899 (P) Something tried to allocate more memory than possible.
3901 =item panic: pad_alloc, %p!=%p
3903 (P) The compiler got confused about which scratch pad it was allocating
3904 and freeing temporaries and lexicals from.
3906 =item panic: pad_free curpad, %p!=%p
3908 (P) The compiler got confused about which scratch pad it was allocating
3909 and freeing temporaries and lexicals from.
3911 =item panic: pad_free po
3913 (P) An invalid scratch pad offset was detected internally.
3915 =item panic: pad_reset curpad, %p!=%p
3917 (P) The compiler got confused about which scratch pad it was allocating
3918 and freeing temporaries and lexicals from.
3920 =item panic: pad_sv po
3922 (P) An invalid scratch pad offset was detected internally.
3924 =item panic: pad_swipe curpad, %p!=%p
3926 (P) The compiler got confused about which scratch pad it was allocating
3927 and freeing temporaries and lexicals from.
3929 =item panic: pad_swipe po
3931 (P) An invalid scratch pad offset was detected internally.
3933 =item panic: pp_iter, type=%u
3935 (P) The foreach iterator got called in a non-loop context frame.
3937 =item panic: pp_match%s
3939 (P) The internal pp_match() routine was called with invalid operational
3942 =item panic: pp_split, pm=%p, s=%p
3944 (P) Something terrible went wrong in setting up for the split.
3946 =item panic: realloc, %s
3948 (P) Something requested a negative number of bytes of realloc.
3950 =item panic: reference miscount on nsv in sv_replace() (%d != 1)
3952 (P) The internal sv_replace() function was handed a new SV with a
3953 reference count other than 1.
3955 =item panic: restartop in %s
3957 (P) Some internal routine requested a goto (or something like it), and
3958 didn't supply the destination.
3960 =item panic: return, type=%u
3962 (P) We popped the context stack to a subroutine or eval context, and
3963 then discovered it wasn't a subroutine or eval context.
3965 =item panic: scan_num, %s
3967 (P) scan_num() got called on something that wasn't a number.
3969 =item panic: Sequence (?{...}): no code block found
3971 (P) while compiling a pattern that has embedded (?{}) or (??{}) code
3972 blocks, perl couldn't locate the code block that should have already been
3973 seen and compiled by perl before control passed to the regex compiler.
3975 =item panic: strxfrm() gets absurd - a => %u, ab => %u
3977 (P) The interpreter's sanity check of the C function strxfrm() failed.
3978 In your current locale the returned transformation of the string "ab"
3979 is shorter than that of the string "a", which makes no sense.
3981 =item panic: sv_chop %s
3983 (P) The sv_chop() routine was passed a position that is not within the
3984 scalar's string buffer.
3986 =item panic: sv_insert, midend=%p, bigend=%p
3988 (P) The sv_insert() routine was told to remove more string than there
3991 =item panic: top_env
3993 (P) The compiler attempted to do a goto, or something weird like that.
3995 =item panic: unimplemented op %s (#%d) called
3997 (P) The compiler is screwed up and attempted to use an op that isn't
3998 permitted at run time.
4000 =item panic: utf16_to_utf8: odd bytelen
4002 (P) Something tried to call utf16_to_utf8 with an odd (as opposed
4003 to even) byte length.
4005 =item panic: utf16_to_utf8_reversed: odd bytelen
4007 (P) Something tried to call utf16_to_utf8_reversed with an odd (as opposed
4008 to even) byte length.
4010 =item panic: yylex, %s
4012 (P) The lexer got into a bad state while processing a case modifier.
4014 =item Parentheses missing around "%s" list
4016 (W parenthesis) You said something like
4022 my ($foo, $bar) = @_;
4024 Remember that "my", "our", "local" and "state" bind tighter than comma.
4026 =item Parsing code internal error (%s)
4028 (F) Parsing code supplied by an extension violated the parser's API in
4031 =item Passing malformed UTF-8 to "%s" is deprecated
4033 (D deprecated, utf8) This message indicates a bug either in the Perl
4034 core or in XS code. Such code was trying to find out if a character,
4035 allegedly stored internally encoded as UTF-8, was of a given type, such
4036 as being punctuation or a digit. But the character was not encoded in
4037 legal UTF-8. The C<%s> is replaced by a string that can be used by
4038 knowledgeable people to determine what the type being checked against
4039 was. If C<utf8> warnings are enabled, a further message is raised,
4040 giving details of the malformation.
4042 =item Pattern subroutine nesting without pos change exceeded limit in regex
4044 (F) You used a pattern that uses too many nested subpattern calls without
4045 consuming any text. Restructure the pattern so text is consumed before
4046 the nesting limit is exceeded.
4048 =item C<-p> destination: %s
4050 (F) An error occurred during the implicit output invoked by the C<-p>
4051 command-line switch. (This output goes to STDOUT unless you've
4052 redirected it with select().)
4054 =item (perhaps you forgot to load "%s"?)
4056 (F) This is an educated guess made in conjunction with the message
4057 "Can't locate object method \"%s\" via package \"%s\"". It often means
4058 that a method requires a package that has not been loaded.
4060 =item Perl folding rules are not up-to-date for 0x%X; please use the perlbug
4061 utility to report; in regex; marked by <-- HERE in m/%s/
4063 (S regexp) You used a regular expression with case-insensitive matching,
4064 and there is a bug in Perl in which the built-in regular expression
4065 folding rules are not accurate. This may lead to incorrect results.
4066 Please report this as a bug using the L<perlbug> utility.
4068 =item Perl_my_%s() not available
4070 (F) Your platform has very uncommon byte-order and integer size,
4071 so it was not possible to set up some or all fixed-width byte-order
4072 conversion functions. This is only a problem when you're using the
4073 '<' or '>' modifiers in (un)pack templates. See L<perlfunc/pack>.
4075 =item Perl %s required (did you mean %s?)--this is only %s, stopped
4077 (F) The code you are trying to run has asked for a newer version of
4078 Perl than you are running. Perhaps C<use 5.10> was written instead
4079 of C<use 5.010> or C<use v5.10>. Without the leading C<v>, the number is
4080 interpreted as a decimal, with every three digits after the
4081 decimal point representing a part of the version number. So 5.10
4082 is equivalent to v5.100.
4084 =item Perl %s required--this is only %s, stopped
4086 (F) The module in question uses features of a version of Perl more
4087 recent than the currently running version. How long has it been since
4088 you upgraded, anyway? See L<perlfunc/require>.
4090 =item PERL_SH_DIR too long
4092 (F) An error peculiar to OS/2. PERL_SH_DIR is the directory to find the
4093 C<sh>-shell in. See "PERL_SH_DIR" in L<perlos2>.
4095 =item PERL_SIGNALS illegal: "%s"
4097 (X) See L<perlrun/PERL_SIGNALS> for legal values.
4099 =item Perls since %s too modern--this is %s, stopped
4101 (F) The code you are trying to run claims it will not run
4102 on the version of Perl you are using because it is too new.
4103 Maybe the code needs to be updated, or maybe it is simply
4104 wrong and the version check should just be removed.
4106 =item perl: warning: Non hex character in '$ENV{PERL_HASH_SEED}', seed only partially set
4108 (S) PERL_HASH_SEED should match /^\s*(?:0x)?[0-9a-fA-F]+\s*\z/ but it
4109 contained a non hex character. This could mean you are not using the
4110 hash seed you think you are.
4112 =item perl: warning: Setting locale failed.
4114 (S) The whole warning message will look something like:
4116 perl: warning: Setting locale failed.
4117 perl: warning: Please check that your locale settings:
4120 are supported and installed on your system.
4121 perl: warning: Falling back to the standard locale ("C").
4123 Exactly what were the failed locale settings varies. In the above the
4124 settings were that the LC_ALL was "En_US" and the LANG had no value.
4125 This error means that Perl detected that you and/or your operating
4126 system supplier and/or system administrator have set up the so-called
4127 locale system but Perl could not use those settings. This was not
4128 dead serious, fortunately: there is a "default locale" called "C" that
4129 Perl can and will use, and the script will be run. Before you really
4130 fix the problem, however, you will get the same error message each
4131 time you run Perl. How to really fix the problem can be found in
4132 L<perllocale> section B<LOCALE PROBLEMS>.
4134 =item perl: warning: strange setting in '$ENV{PERL_PERTURB_KEYS}': '%s'
4136 (S) Perl was run with the environment variable PERL_PERTURB_KEYS defined
4137 but containing an unexpected value. The legal values of this setting
4140 Numeric | String | Result
4141 --------+---------------+-----------------------------------------
4142 0 | NO | Disables key traversal randomization
4143 1 | RANDOM | Enables full key traversal randomization
4144 2 | DETERMINISTIC | Enables repeatable key traversal
4147 Both numeric and string values are accepted, but note that string values are
4148 case sensitive. The default for this setting is "RANDOM" or 1.
4150 =item pid %x not a child
4152 (W exec) A warning peculiar to VMS. Waitpid() was asked to wait for a
4153 process which isn't a subprocess of the current process. While this is
4154 fine from VMS' perspective, it's probably not what you intended.
4156 =item 'P' must have an explicit size in unpack
4158 (F) The unpack format P must have an explicit size, not "*".
4160 =item POSIX class [:%s:] unknown in regex; marked by <-- HERE in m/%s/
4162 (F) The class in the character class [: :] syntax is unknown. The <-- HERE
4163 shows whereabouts in the regular expression the problem was discovered.
4164 Note that the POSIX character classes do B<not> have the C<is> prefix
4165 the corresponding C interfaces have: in other words, it's C<[[:print:]]>,
4166 not C<isprint>. See L<perlre>.
4168 =item POSIX getpgrp can't take an argument
4170 (F) Your system has POSIX getpgrp(), which takes no argument, unlike
4171 the BSD version, which takes a pid.
4173 =item POSIX syntax [%c %c] belongs inside character classes in regex; marked by
4176 (W regexp) The character class constructs [: :], [= =], and [. .] go
4177 I<inside> character classes, the [] are part of the construct, for example:
4178 /[012[:alpha:]345]/. Note that [= =] and [. .] are not currently
4179 implemented; they are simply placeholders for future extensions and
4180 will cause fatal errors. The <-- HERE shows whereabouts in the regular
4181 expression the problem was discovered. See L<perlre>.
4183 =item POSIX syntax [. .] is reserved for future extensions in regex; marked by
4186 (F) Within regular expression character classes ([]) the syntax beginning
4187 with "[." and ending with ".]" is reserved for future extensions. If you
4188 need to represent those character sequences inside a regular expression
4189 character class, just quote the square brackets with the backslash: "\[."
4190 and ".\]". The <-- HERE shows whereabouts in the regular expression the
4191 problem was discovered. See L<perlre>.
4193 =item POSIX syntax [= =] is reserved for future extensions in regex; marked by
4196 (F) Within regular expression character classes ([]) the syntax beginning
4197 with "[=" and ending with "=]" is reserved for future extensions. If you
4198 need to represent those character sequences inside a regular expression
4199 character class, just quote the square brackets with the backslash: "\[="
4200 and "=\]". The <-- HERE shows whereabouts in the regular expression the
4201 problem was discovered. See L<perlre>.
4203 =item Possible attempt to put comments in qw() list
4205 (W qw) qw() lists contain items separated by whitespace; as with literal
4206 strings, comment characters are not ignored, but are instead treated as
4207 literal data. (You may have used different delimiters than the
4208 parentheses shown here; braces are also frequently used.)
4210 You probably wrote something like this:
4217 when you should have written this:
4224 If you really want comments, build your list the
4225 old-fashioned way, with quotes and commas:
4229 'b', # another comment
4232 =item Possible attempt to separate words with commas
4234 (W qw) qw() lists contain items separated by whitespace; therefore
4235 commas aren't needed to separate the items. (You may have used
4236 different delimiters than the parentheses shown here; braces are also
4239 You probably wrote something like this:
4243 which puts literal commas into some of the list items. Write it without
4244 commas if you don't want them to appear in your data:
4248 =item Possible memory corruption: %s overflowed 3rd argument
4250 (F) An ioctl() or fcntl() returned more than Perl was bargaining for.
4251 Perl guesses a reasonable buffer size, but puts a sentinel byte at the
4252 end of the buffer just in case. This sentinel byte got clobbered, and
4253 Perl assumes that memory is now corrupted. See L<perlfunc/ioctl>.
4255 =item Possible precedence issue with control flow operator
4257 (W syntax) There is a possible problem with the mixing of a control
4258 flow operator (e.g. C<return>) and a low-precedence operator like
4261 sub { return $a or $b; }
4265 sub { (return $a) or $b; }
4267 Which is effectively just:
4271 Either use parentheses or the high-precedence variant of the operator.
4273 Note this may be also triggered for constructs like:
4277 =item Possible precedence problem on bitwise %c operator
4279 (W precedence) Your program uses a bitwise logical operator in conjunction
4280 with a numeric comparison operator, like this :
4282 if ($x & $y == 0) { ... }
4284 This expression is actually equivalent to C<$x & ($y == 0)>, due to the
4285 higher precedence of C<==>. This is probably not what you want. (If you
4286 really meant to write this, disable the warning, or, better, put the
4287 parentheses explicitly and write C<$x & ($y == 0)>).
4289 =item Possible unintended interpolation of $\ in regex
4291 (W ambiguous) You said something like C<m/$\/> in a regex.
4292 The regex C<m/foo$\s+bar/m> translates to: match the word 'foo', the output
4293 record separator (see L<perlvar/$\>) and the letter 's' (one time or more)
4294 followed by the word 'bar'.
4296 If this is what you intended then you can silence the warning by using
4297 C<m/${\}/> (for example: C<m/foo${\}s+bar/>).
4299 If instead you intended to match the word 'foo' at the end of the line
4300 followed by whitespace and the word 'bar' on the next line then you can use
4301 C<m/$(?)\/> (for example: C<m/foo$(?)\s+bar/>).
4303 =item Possible unintended interpolation of %s in string
4305 (W ambiguous) You said something like '@foo' in a double-quoted string
4306 but there was no array C<@foo> in scope at the time. If you wanted a
4307 literal @foo, then write it as \@foo; otherwise find out what happened
4308 to the array you apparently lost track of.
4310 =item Postfix dereference is experimental
4312 (S experimental::postderef) This warning is emitted if you use
4313 the experimental postfix dereference syntax. Simply suppress the
4314 warning if you want to use the feature, but know that in doing
4315 so you are taking the risk of using an experimental feature which
4316 may change or be removed in a future Perl version:
4318 no warnings "experimental::postderef";
4319 use feature "postderef", "postderef_qq";
4325 =item Precedence problem: open %s should be open(%s)
4327 (S precedence) The old irregular construct
4331 is now misinterpreted as
4335 because of the strict regularization of Perl 5's grammar into unary and
4336 list operators. (The old open was a little of both.) You must put
4337 parentheses around the filehandle, or use the new "or" operator instead
4340 =item Premature end of script headers
4344 =item printf() on closed filehandle %s
4346 (W closed) The filehandle you're writing to got itself closed sometime
4347 before now. Check your control flow.
4349 =item print() on closed filehandle %s
4351 (W closed) The filehandle you're printing on got itself closed sometime
4352 before now. Check your control flow.
4354 =item Process terminated by SIG%s
4356 (W) This is a standard message issued by OS/2 applications, while *nix
4357 applications die in silence. It is considered a feature of the OS/2
4358 port. One can easily disable this by appropriate sighandlers, see
4359 L<perlipc/"Signals">. See also "Process terminated by SIGTERM/SIGINT"
4362 =item Property '%s' is unknown in regex; marked by <-- HERE in m/%s/
4364 (F) The named property which you specified via C<\p> or C<\P> is not one
4365 known to Perl. Perhaps you misspelled the name? See
4366 L<perluniprops/Properties accessible through \p{} and \P{}>
4367 for a complete list of available official
4368 properties. If it is a L<user-defined property|perlunicode/User-Defined Character Properties>
4369 it must have been defined by the time the regular expression is
4372 =item Prototype after '%c' for %s : %s
4374 (W illegalproto) A character follows % or @ in a prototype. This is
4375 useless, since % and @ gobble the rest of the subroutine arguments.
4377 =item Prototype mismatch: %s vs %s
4379 (S prototype) The subroutine being declared or defined had previously been
4380 declared or defined with a different function prototype.
4382 =item Prototype not terminated
4384 (F) You've omitted the closing parenthesis in a function prototype
4387 =item Prototype '%s' overridden by attribute 'prototype(%s)' in %s
4389 (W prototype) A prototype was declared in both the parentheses after
4390 the sub name and via the prototype attribute. The prototype in
4391 parentheses is useless, since it will be replaced by the prototype
4392 from the attribute before it's ever used.
4394 =item \p{} uses Unicode rules, not locale rules
4396 (W) You compiled a regular expression that contained a Unicode property
4397 match (C<\p> or C<\P>), but the regular expression is also being told to
4398 use the run-time locale, not Unicode. Instead, use a POSIX character
4399 class, which should know about the locale's rules.
4400 (See L<perlrecharclass/POSIX Character Classes>.)
4402 Even if the run-time locale is ISO 8859-1 (Latin1), which is a subset of
4403 Unicode, some properties will give results that are not valid for that
4406 Here are a couple of examples to help you see what's going on. If the
4407 locale is ISO 8859-7, the character at code point 0xD7 is the "GREEK
4408 CAPITAL LETTER CHI". But in Unicode that code point means the
4409 "MULTIPLICATION SIGN" instead, and C<\p> always uses the Unicode
4410 meaning. That means that C<\p{Alpha}> won't match, but C<[[:alpha:]]>
4411 should. Only in the Latin1 locale are all the characters in the same
4412 positions as they are in Unicode. But, even here, some properties give
4413 incorrect results. An example is C<\p{Changes_When_Uppercased}> which
4414 is true for "LATIN SMALL LETTER Y WITH DIAERESIS", but since the upper
4415 case of that character is not in Latin1, in that locale it doesn't
4416 change when upper cased.
4418 =item Quantifier follows nothing in regex; marked by <-- HERE in m/%s/
4420 (F) You started a regular expression with a quantifier. Backslash it if
4421 you meant it literally. The <-- HERE shows whereabouts in the regular
4422 expression the problem was discovered. See L<perlre>.
4424 =item Quantifier in {,} bigger than %d in regex; marked by <-- HERE in m/%s/
4426 (F) There is currently a limit to the size of the min and max values of
4427 the {min,max} construct. The <-- HERE shows whereabouts in the regular
4428 expression the problem was discovered. See L<perlre>.
4430 =item Quantifier {n,m} with n > m can't match in regex
4432 =item Quantifier {n,m} with n > m can't match in regex; marked by <-- HERE in m/%s/
4434 (W regexp) Minima should be less than or equal to maxima. If you really
4435 want your regexp to match something 0 times, just put {0}.
4437 =item Quantifier unexpected on zero-length expression in regex; marked by <--
4440 (W regexp) You applied a regular expression quantifier in a place where
4441 it makes no sense, such as on a zero-width assertion. Try putting the
4442 quantifier inside the assertion instead. For example, the way to match
4443 "abc" provided that it is followed by three repetitions of "xyz" is
4444 C</abc(?=(?:xyz){3})/>, not C</abc(?=xyz){3}/>.
4446 The <-- HERE shows whereabouts in the regular expression the problem was
4449 =item Range iterator outside integer range
4451 (F) One (or both) of the numeric arguments to the range operator ".."
4452 are outside the range which can be represented by integers internally.
4453 One possible workaround is to force Perl to use magical string increment
4454 by prepending "0" to your numbers.
4456 =item readdir() attempted on invalid dirhandle %s
4458 (W io) The dirhandle you're reading from is either closed or not really
4459 a dirhandle. Check your control flow.
4461 =item readline() on closed filehandle %s
4463 (W closed) The filehandle you're reading from got itself closed sometime
4464 before now. Check your control flow.
4466 =item read() on closed filehandle %s
4468 (W closed) You tried to read from a closed filehandle.
4470 =item read() on unopened filehandle %s
4472 (W unopened) You tried to read from a filehandle that was never opened.
4474 =item Reallocation too large: %x
4476 (F) You can't allocate more than 64K on an MS-DOS machine.
4478 =item realloc() of freed memory ignored
4480 (S malloc) An internal routine called realloc() on something that had
4483 =item Recompile perl with B<-D>DEBUGGING to use B<-D> switch
4485 (S debugging) You can't use the B<-D> option unless the code to produce
4486 the desired output is compiled into Perl, which entails some overhead,
4487 which is why it's currently left out of your copy.
4489 =item Recursive call to Perl_load_module in PerlIO_find_layer
4491 (P) It is currently not permitted to load modules when creating
4492 a filehandle inside an %INC hook. This can happen with C<open my
4493 $fh, '<', \$scalar>, which implicitly loads PerlIO::scalar. Try
4494 loading PerlIO::scalar explicitly first.
4496 =item Recursive inheritance detected in package '%s'
4498 (F) While calculating the method resolution order (MRO) of a package, Perl
4499 believes it found an infinite loop in the C<@ISA> hierarchy. This is a
4500 crude check that bails out after 100 levels of C<@ISA> depth.
4502 =item refcnt_dec: fd %d%s
4504 =item refcnt: fd %d%s
4506 =item refcnt_inc: fd %d%s
4508 (P) Perl's I/O implementation failed an internal consistency check. If
4509 you see this message, something is very wrong.
4511 =item Reference found where even-sized list expected
4513 (W misc) You gave a single reference where Perl was expecting a list
4514 with an even number of elements (for assignment to a hash). This
4515 usually means that you used the anon hash constructor when you meant
4516 to use parens. In any case, a hash requires key/value B<pairs>.
4518 %hash = { one => 1, two => 2, }; # WRONG
4519 %hash = [ qw/ an anon array / ]; # WRONG
4520 %hash = ( one => 1, two => 2, ); # right
4521 %hash = qw( one 1 two 2 ); # also fine
4523 =item Reference is already weak
4525 (W misc) You have attempted to weaken a reference that is already weak.
4526 Doing so has no effect.
4528 =item Reference to invalid group 0 in regex; marked by <-- HERE in m/%s/
4530 (F) You used C<\g0> or similar in a regular expression. You may refer
4531 to capturing parentheses only with strictly positive integers
4532 (normal backreferences) or with strictly negative integers (relative
4533 backreferences). Using 0 does not make sense.
4535 =item Reference to nonexistent group in regex; marked by <-- HERE in m/%s/
4537 (F) You used something like C<\7> in your regular expression, but there are
4538 not at least seven sets of capturing parentheses in the expression. If
4539 you wanted to have the character with ordinal 7 inserted into the regular
4540 expression, prepend zeroes to make it three digits long: C<\007>
4542 The <-- HERE shows whereabouts in the regular expression the problem was
4545 =item Reference to nonexistent named group in regex; marked by <-- HERE in m/%s/
4547 (F) You used something like C<\k'NAME'> or C<< \k<NAME> >> in your regular
4548 expression, but there is no corresponding named capturing parentheses
4549 such as C<(?'NAME'...)> or C<< (?<NAME>...) >>. Check if the name has been
4550 spelled correctly both in the backreference and the declaration.
4552 The <-- HERE shows whereabouts in the regular expression the problem was
4555 =item Reference to nonexistent or unclosed group in regex; marked by <-- HERE
4558 (F) You used something like C<\g{-7}> in your regular expression, but there
4559 are not at least seven sets of closed capturing parentheses in the
4560 expression before where the C<\g{-7}> was located.
4562 The <-- HERE shows whereabouts in the regular expression the problem was
4565 =item regexp memory corruption
4567 (P) The regular expression engine got confused by what the regular
4568 expression compiler gave it.
4570 =item Regexp modifier "/%c" may appear a maximum of twice
4572 =item Regexp modifier "/%c" may not appear twice
4574 (F syntax, regexp) The regular expression pattern had too many occurrences
4575 of the specified modifier. Remove the extraneous ones.
4577 =item Regexp modifier "%c" may not appear after the "-" in regex; marked by <--
4580 (F) Turning off the given modifier has the side effect of turning on
4581 another one. Perl currently doesn't allow this. Reword the regular
4582 expression to use the modifier you want to turn on (and place it before
4583 the minus), instead of the one you want to turn off.
4585 =item Regexp modifiers "/%c" and "/%c" are mutually exclusive
4587 (F syntax, regexp) The regular expression pattern had more than one of these
4588 mutually exclusive modifiers. Retain only the modifier that is
4589 supposed to be there.
4591 =item Regexp out of space in regex m/%s/
4593 (P) A "can't happen" error, because safemalloc() should have caught it
4596 =item Repeated format line will never terminate (~~ and @#)
4598 (F) Your format contains the ~~ repeat-until-blank sequence and a
4599 numeric field that will never go blank so that the repetition never
4600 terminates. You might use ^# instead. See L<perlform>.
4602 =item Replacement list is longer than search list
4604 (W misc) You have used a replacement list that is longer than the
4605 search list. So the additional elements in the replacement list
4608 =item '%s' resolved to '\o{%s}%d'
4610 (W misc, regexp) You wrote something like C<\08>, or C<\179> in a
4611 double-quotish string. All but the last digit is treated as a single
4612 character, specified in octal. The last digit is the next character in
4613 the string. To tell Perl that this is indeed what you want, you can use
4614 the C<\o{ }> syntax, or use exactly three digits to specify the octal
4617 =item Reversed %s= operator
4619 (W syntax) You wrote your assignment operator backwards. The = must
4620 always come last, to avoid ambiguity with subsequent unary operators.
4622 =item rewinddir() attempted on invalid dirhandle %s
4624 (W io) The dirhandle you tried to do a rewinddir() on is either closed or not
4625 really a dirhandle. Check your control flow.
4627 =item Scalars leaked: %d
4629 (S internal) Something went wrong in Perl's internal bookkeeping
4630 of scalars: not all scalar variables were deallocated by the time
4631 Perl exited. What this usually indicates is a memory leak, which
4632 is of course bad, especially if the Perl program is intended to be
4635 =item Scalar value @%s[%s] better written as $%s[%s]
4637 (W syntax) You've used an array slice (indicated by @) to select a
4638 single element of an array. Generally it's better to ask for a scalar
4639 value (indicated by $). The difference is that C<$foo[&bar]> always
4640 behaves like a scalar, both when assigning to it and when evaluating its
4641 argument, while C<@foo[&bar]> behaves like a list when you assign to it,
4642 and provides a list context to its subscript, which can do weird things
4643 if you're expecting only one subscript.
4645 On the other hand, if you were actually hoping to treat the array
4646 element as a list, you need to look into how references work, because
4647 Perl will not magically convert between scalars and lists for you. See
4650 =item Scalar value @%s{%s} better written as $%s{%s}
4652 (W syntax) You've used a hash slice (indicated by @) to select a single
4653 element of a hash. Generally it's better to ask for a scalar value
4654 (indicated by $). The difference is that C<$foo{&bar}> always behaves
4655 like a scalar, both when assigning to it and when evaluating its
4656 argument, while C<@foo{&bar}> behaves like a list when you assign to it,
4657 and provides a list context to its subscript, which can do weird things
4658 if you're expecting only one subscript.
4660 On the other hand, if you were actually hoping to treat the hash element
4661 as a list, you need to look into how references work, because Perl will
4662 not magically convert between scalars and lists for you. See
4665 =item Scalar value %%s[%s] better written as $%s[%s]
4667 (W syntax) In scalar context, you've used an array index/value slice
4668 (indicated by %) to select a single element of an array. Generally
4669 it's better to ask for a scalar value (indicated by $). The difference
4670 is that C<$foo[&bar]> always behaves like a scalar, both in the value it
4671 returns and when evaluating its argument, while C<%foo[&bar]> provides
4672 a list context to its subscript, which can do weird things if you're
4673 expecting only one subscript. When called in list context, it also
4674 returns the index (what C<&bar> returns) in addition to the value.
4676 =item Scalar value %%s{%s} better written as $%s{%s}
4678 (W syntax) In scalar context, you've used a hash key/value slice
4679 (indicated by %) to select a single element of a hash. Generally it's
4680 better to ask for a scalar value (indicated by $). The difference
4681 is that C<$foo{&bar}> always behaves like a scalar, both in the value
4682 it returns and when evaluating its argument, while C<@foo{&bar}> and
4683 provides a list context to its subscript, which can do weird things
4684 if you're expecting only one subscript. When called in list context,
4685 it also returns the key in addition to the value.
4687 =item Search pattern not terminated
4689 (F) The lexer couldn't find the final delimiter of a // or m{}
4690 construct. Remember that bracketing delimiters count nesting level.
4691 Missing the leading C<$> from a variable C<$m> may cause this error.
4693 Note that since Perl 5.9.0 a // can also be the I<defined-or>
4694 construct, not just the empty search pattern. Therefore code written
4695 in Perl 5.9.0 or later that uses the // as the I<defined-or> can be
4696 misparsed by pre-5.9.0 Perls as a non-terminated search pattern.
4698 =item Search pattern not terminated or ternary operator parsed as search pattern
4700 (F) The lexer couldn't find the final delimiter of a C<?PATTERN?>
4703 The question mark is also used as part of the ternary operator (as in
4704 C<foo ? 0 : 1>) leading to some ambiguous constructions being wrongly
4705 parsed. One way to disambiguate the parsing is to put parentheses around
4706 the conditional expression, i.e. C<(foo) ? 0 : 1>.
4708 =item seekdir() attempted on invalid dirhandle %s
4710 (W io) The dirhandle you are doing a seekdir() on is either closed or not
4711 really a dirhandle. Check your control flow.
4713 =item %sseek() on unopened filehandle
4715 (W unopened) You tried to use the seek() or sysseek() function on a
4716 filehandle that was either never opened or has since been closed.
4718 =item select not implemented
4720 (F) This machine doesn't implement the select() system call.
4722 =item Self-ties of arrays and hashes are not supported
4724 (F) Self-ties are of arrays and hashes are not supported in
4725 the current implementation.
4727 =item Semicolon seems to be missing
4729 (W semicolon) A nearby syntax error was probably caused by a missing
4730 semicolon, or possibly some other missing operator, such as a comma.
4732 =item semi-panic: attempt to dup freed string
4734 (S internal) The internal newSVsv() routine was called to duplicate a
4735 scalar that had previously been marked as free.
4737 =item sem%s not implemented
4739 (F) You don't have System V semaphore IPC on your system.
4741 =item send() on closed socket %s
4743 (W closed) The socket you're sending to got itself closed sometime
4744 before now. Check your control flow.
4746 =item Sequence (? incomplete in regex; marked by <-- HERE in m/%s/
4748 (F) A regular expression ended with an incomplete extension (?. The
4749 <-- HERE shows whereabouts in the regular expression the problem was
4750 discovered. See L<perlre>.
4752 =item Sequence (?%s...) not implemented in regex; marked by <-- HERE in m/%s/
4754 (F) A proposed regular expression extension has the character reserved
4755 but has not yet been written. The <-- HERE shows whereabouts in the
4756 regular expression the problem was discovered. See L<perlre>.
4758 =item Sequence (?%s...) not recognized in regex; marked by <-- HERE in m/%s/
4760 (F) You used a regular expression extension that doesn't make sense. The
4761 <-- HERE shows whereabouts in the regular expression the problem was
4762 discovered. This happens when using the C<(?^...)> construct to tell
4763 Perl to use the default regular expression modifiers, and you
4764 redundantly specify a default modifier. For other
4765 causes, see L<perlre>.
4767 =item Sequence (?#... not terminated in regex m/%s/
4769 (F) A regular expression comment must be terminated by a closing
4770 parenthesis. Embedded parentheses aren't allowed. See
4773 =item Sequence \%s... not terminated in regex; marked by <-- HERE in m/%s/
4775 (F) The regular expression expects a mandatory argument following the escape
4776 sequence and this has been omitted or incorrectly written.
4778 =item Sequence (?{...}) not terminated with ')'
4780 (F) The end of the perl code contained within the {...} must be
4781 followed immediately by a ')'.
4783 =item Server error (a.k.a. "500 Server error")
4785 (A) This is the error message generally seen in a browser window
4786 when trying to run a CGI program (including SSI) over the web. The
4787 actual error text varies widely from server to server. The most
4788 frequently-seen variants are "500 Server error", "Method (something)
4789 not permitted", "Document contains no data", "Premature end of script
4790 headers", and "Did not produce a valid header".
4792 B<This is a CGI error, not a Perl error>.
4794 You need to make sure your script is executable, is accessible by
4795 the user CGI is running the script under (which is probably not the
4796 user account you tested it under), does not rely on any environment
4797 variables (like PATH) from the user it isn't running under, and isn't
4798 in a location where the CGI server can't find it, basically, more or
4799 less. Please see the following for more information:
4801 http://www.perl.org/CGI_MetaFAQ.html
4802 http://www.htmlhelp.org/faq/cgifaq.html
4803 http://www.w3.org/Security/Faq/
4805 You should also look at L<perlfaq9>.
4807 =item setegid() not implemented
4809 (F) You tried to assign to C<$)>, and your operating system doesn't
4810 support the setegid() system call (or equivalent), or at least Configure
4813 =item seteuid() not implemented
4815 (F) You tried to assign to C<< $> >>, and your operating system doesn't
4816 support the seteuid() system call (or equivalent), or at least Configure
4819 =item setpgrp can't take arguments
4821 (F) Your system has the setpgrp() from BSD 4.2, which takes no
4822 arguments, unlike POSIX setpgid(), which takes a process ID and process
4825 =item setrgid() not implemented
4827 (F) You tried to assign to C<$(>, and your operating system doesn't
4828 support the setrgid() system call (or equivalent), or at least Configure
4831 =item setruid() not implemented
4833 (F) You tried to assign to C<$<>, and your operating system doesn't
4834 support the setruid() system call (or equivalent), or at least Configure
4837 =item setsockopt() on closed socket %s
4839 (W closed) You tried to set a socket option on a closed socket. Did you
4840 forget to check the return value of your socket() call? See
4841 L<perlfunc/setsockopt>.
4843 =item shm%s not implemented
4845 (F) You don't have System V shared memory IPC on your system.
4847 =item !=~ should be !~
4849 (W syntax) The non-matching operator is !~, not !=~. !=~ will be
4850 interpreted as the != (numeric not equal) and ~ (1's complement)
4851 operators: probably not what you intended.
4853 =item <> should be quotes
4855 (F) You wrote C<< require <file> >> when you should have written
4858 =item /%s/ should probably be written as "%s"
4860 (W syntax) You have used a pattern where Perl expected to find a string,
4861 as in the first argument to C<join>. Perl will treat the true or false
4862 result of matching the pattern against $_ as the string, which is
4863 probably not what you had in mind.
4865 =item shutdown() on closed socket %s
4867 (W closed) You tried to do a shutdown on a closed socket. Seems a bit
4870 =item SIG%s handler "%s" not defined
4872 (W signal) The signal handler named in %SIG doesn't, in fact, exist.
4873 Perhaps you put it into the wrong package?
4875 =item Slab leaked from cv %p
4877 (S) If you see this message, then something is seriously wrong with the
4878 internal bookkeeping of op trees. An op tree needed to be freed after
4879 a compilation error, but could not be found, so it was leaked instead.
4881 =item sleep(%u) too large
4883 (W overflow) You called C<sleep> with a number that was larger than
4884 it can reliably handle and C<sleep> probably slept for less time than
4887 =item Smart matching a non-overloaded object breaks encapsulation
4889 (F) You should not use the C<~~> operator on an object that does not
4890 overload it: Perl refuses to use the object's underlying structure
4891 for the smart match.
4893 =item Smartmatch is experimental
4895 (S experimental::smartmatch) This warning is emitted if you
4896 use the smartmatch (C<~~>) operator. This is currently an experimental
4897 feature, and its details are subject to change in future releases of
4898 Perl. Particularly, its current behavior is noticed for being
4899 unnecessarily complex and unintuitive, and is very likely to be
4902 =item sort is now a reserved word
4904 (F) An ancient error message that almost nobody ever runs into anymore.
4905 But before sort was a keyword, people sometimes used it as a filehandle.
4907 =item Sort subroutine didn't return single value
4909 (F) A sort comparison subroutine written in XS must return exactly one
4910 item. See L<perlfunc/sort>.
4912 =item Source filters apply only to byte streams
4914 (F) You tried to activate a source filter (usually by loading a
4915 source filter module) within a string passed to C<eval>. This is
4916 not permitted under the C<unicode_eval> feature. Consider using
4917 C<evalbytes> instead. See L<feature>.
4919 =item splice() offset past end of array
4921 (W misc) You attempted to specify an offset that was past the end of
4922 the array passed to splice(). Splicing will instead commence at the
4923 end of the array, rather than past it. If this isn't what you want,
4924 try explicitly pre-extending the array by assigning $#array = $offset.
4925 See L<perlfunc/splice>.
4929 (P) The split was looping infinitely. (Obviously, a split shouldn't
4930 iterate more times than there are characters of input, which is what
4931 happened.) See L<perlfunc/split>.
4933 =item Statement unlikely to be reached
4935 (W exec) You did an exec() with some statement after it other than a
4936 die(). This is almost always an error, because exec() never returns
4937 unless there was a failure. You probably wanted to use system()
4938 instead, which does return. To suppress this warning, put the exec() in
4941 =item "state %s" used in sort comparison
4943 (W syntax) The package variables $a and $b are used for sort comparisons.
4944 You used $a or $b in as an operand to the C<< <=> >> or C<cmp> operator inside a
4945 sort comparison block, and the variable had earlier been declared as a
4946 lexical variable. Either qualify the sort variable with the package
4947 name, or rename the lexical variable.
4949 =item "state" variable %s can't be in a package
4951 (F) Lexically scoped variables aren't in a package, so it doesn't make
4952 sense to try to declare one with a package qualifier on the front. Use
4953 local() if you want to localize a package variable.
4955 =item stat() on unopened filehandle %s
4957 (W unopened) You tried to use the stat() function on a filehandle that
4958 was either never opened or has since been closed.
4960 =item Strings with code points over 0xFF may not be mapped into in-memory file handles
4962 (W utf8) You tried to open a reference to a scalar for read or append
4963 where the scalar contained code points over 0xFF. In-memory files
4964 model on-disk files and can only contain bytes.
4966 =item Stub found while resolving method "%s" overloading "%s" in package "%s"
4968 (P) Overloading resolution over @ISA tree may be broken by importation
4969 stubs. Stubs should never be implicitly created, but explicit calls to
4970 C<can> may break this.
4972 =item Subroutine "&%s" is not available
4974 (W closure) During compilation, an inner named subroutine or eval is
4975 attempting to capture an outer lexical subroutine that is not currently
4976 available. This can happen for one of two reasons. First, the lexical
4977 subroutine may be declared in an outer anonymous subroutine that has not
4978 yet been created. (Remember that named subs are created at compile time,
4979 while anonymous subs are created at run-time.) For example,
4981 sub { my sub a {...} sub f { \&a } }
4983 At the time that f is created, it can't capture the current the "a" sub,
4984 since the anonymous subroutine hasn't been created yet. Conversely, the
4985 following won't give a warning since the anonymous subroutine has by now
4986 been created and is live:
4988 sub { my sub a {...} eval 'sub f { \&a }' }->();
4990 The second situation is caused by an eval accessing a variable that has
4991 gone out of scope, for example,
4999 Here, when the '\&a' in the eval is being compiled, f() is not currently
5000 being executed, so its &a is not available for capture.
5002 =item "%s" subroutine &%s masks earlier declaration in same %s
5004 (W misc) A "my" or "state" subroutine has been redeclared in the
5005 current scope or statement, effectively eliminating all access to
5006 the previous instance. This is almost always a typographical error.
5007 Note that the earlier subroutine will still exist until the end of
5008 the scope or until all closure references to it are destroyed.
5010 =item Subroutine %s redefined
5012 (W redefine) You redefined a subroutine. To suppress this warning, say
5015 no warnings 'redefine';
5016 eval "sub name { ... }";
5019 =item Substitution loop
5021 (P) The substitution was looping infinitely. (Obviously, a substitution
5022 shouldn't iterate more times than there are characters of input, which
5023 is what happened.) See the discussion of substitution in
5024 L<perlop/"Regexp Quote-Like Operators">.
5026 =item Substitution pattern not terminated
5028 (F) The lexer couldn't find the interior delimiter of an s/// or s{}{}
5029 construct. Remember that bracketing delimiters count nesting level.
5030 Missing the leading C<$> from variable C<$s> may cause this error.
5032 =item Substitution replacement not terminated
5034 (F) The lexer couldn't find the final delimiter of an s/// or s{}{}
5035 construct. Remember that bracketing delimiters count nesting level.
5036 Missing the leading C<$> from variable C<$s> may cause this error.
5038 =item substr outside of string
5040 (W substr)(F) You tried to reference a substr() that pointed outside of
5041 a string. That is, the absolute value of the offset was larger than the
5042 length of the string. See L<perlfunc/substr>. This warning is fatal if
5043 substr is used in an lvalue context (as the left hand side of an
5044 assignment or as a subroutine argument for example).
5046 =item sv_upgrade from type %d down to type %d
5048 (P) Perl tried to force the upgrade of an SV to a type which was actually
5049 inferior to its current type.
5051 =item SWASHNEW didn't return an HV ref
5053 (P) Something went wrong internally when Perl was trying to look up
5056 =item Switch (?(condition)... contains too many branches in regex; marked by
5059 (F) A (?(condition)if-clause|else-clause) construct can have at most
5060 two branches (the if-clause and the else-clause). If you want one or
5061 both to contain alternation, such as using C<this|that|other>, enclose
5062 it in clustering parentheses:
5064 (?(condition)(?:this|that|other)|else-clause)
5066 The <-- HERE shows whereabouts in the regular expression the problem
5067 was discovered. See L<perlre>.
5069 =item Switch condition not recognized in regex; marked by <-- HERE in m/%s/
5071 (F) If the argument to the (?(...)if-clause|else-clause) construct is
5072 a number, it can be only a number. The <-- HERE shows whereabouts in
5073 the regular expression the problem was discovered. See L<perlre>.
5075 =item switching effective %s is not implemented
5077 (F) While under the C<use filetest> pragma, we cannot switch the real
5078 and effective uids or gids.
5082 (F) The final summary message when a C<perl -c> succeeds.
5086 (F) Probably means you had a syntax error. Common reasons include:
5088 A keyword is misspelled.
5089 A semicolon is missing.
5091 An opening or closing parenthesis is missing.
5092 An opening or closing brace is missing.
5093 A closing quote is missing.
5095 Often there will be another error message associated with the syntax
5096 error giving more information. (Sometimes it helps to turn on B<-w>.)
5097 The error message itself often tells you where it was in the line when
5098 it decided to give up. Sometimes the actual error is several tokens
5099 before this, because Perl is good at understanding random input.
5100 Occasionally the line number may be misleading, and once in a blue moon
5101 the only way to figure out what's triggering the error is to call
5102 C<perl -c> repeatedly, chopping away half the program each time to see
5103 if the error went away. Sort of the cybernetic version of S<20 questions>.
5105 =item syntax error at line %d: '%s' unexpected
5107 (A) You've accidentally run your script through the Bourne shell instead
5108 of Perl. Check the #! line, or manually feed your script into Perl
5111 =item syntax error in file %s at line %d, next 2 tokens "%s"
5113 (F) This error is likely to occur if you run a perl5 script through
5114 a perl4 interpreter, especially if the next 2 tokens are "use strict"
5115 or "my $var" or "our $var".
5117 =item Syntax error in (?[...]) in regex m/%s/
5119 (F) Perl could not figure out what you meant inside this construct; this
5120 notifies you that it is giving up trying.
5122 =item sysread() on closed filehandle %s
5124 (W closed) You tried to read from a closed filehandle.
5126 =item sysread() on unopened filehandle %s
5128 (W unopened) You tried to read from a filehandle that was never opened.
5130 =item System V %s is not implemented on this machine
5132 (F) You tried to do something with a function beginning with "sem",
5133 "shm", or "msg" but that System V IPC is not implemented in your
5134 machine. In some machines the functionality can exist but be
5135 unconfigured. Consult your system support.
5137 =item syswrite() on closed filehandle %s
5139 (W closed) The filehandle you're writing to got itself closed sometime
5140 before now. Check your control flow.
5142 =item C<-T> and C<-B> not implemented on filehandles
5144 (F) Perl can't peek at the stdio buffer of filehandles when it doesn't
5145 know about your kind of stdio. You'll have to use a filename instead.
5147 =item Target of goto is too deeply nested
5149 (F) You tried to use C<goto> to reach a label that was too deeply nested
5150 for Perl to reach. Perl is doing you a favor by refusing.
5152 =item telldir() attempted on invalid dirhandle %s
5154 (W io) The dirhandle you tried to telldir() is either closed or not really
5155 a dirhandle. Check your control flow.
5157 =item tell() on unopened filehandle
5159 (W unopened) You tried to use the tell() function on a filehandle that
5160 was either never opened or has since been closed.
5162 =item That use of $[ is unsupported
5164 (F) Assignment to C<$[> is now strictly circumscribed, and interpreted
5165 as a compiler directive. You may say only one of
5174 This is to prevent the problem of one module changing the array base out
5175 from under another module inadvertently. See L<perlvar/$[> and L<arybase>.
5177 =item The crypt() function is unimplemented due to excessive paranoia.
5179 (F) Configure couldn't find the crypt() function on your machine,
5180 probably because your vendor didn't supply it, probably because they
5181 think the U.S. Government thinks it's a secret, or at least that they
5182 will continue to pretend that it is. And if you quote me on that, I
5185 =item The %s feature is experimental
5187 (S experimental) This warning is emitted if you enable an experimental
5188 feature via C<use feature>. Simply suppress the warning if you want
5189 to use the feature, but know that in doing so you are taking the risk
5190 of using an experimental feature which may change or be removed in a
5191 future Perl version:
5193 no warnings "experimental::lexical_subs";
5194 use feature "lexical_subs";
5196 =item The %s function is unimplemented
5198 (F) The function indicated isn't implemented on this architecture,
5199 according to the probings of Configure.
5201 =item The lexical_subs feature is experimental
5203 (S experimental::lexical_subs) This warning is emitted if you
5204 declare a sub with C<my> or C<state>. Simply suppress the warning
5205 if you want to use the feature, but know that in doing so you
5206 are taking the risk of using an experimental feature which may
5207 change or be removed in a future Perl version:
5209 no warnings "experimental::lexical_subs";
5210 use feature "lexical_subs";
5213 =item The regex_sets feature is experimental
5215 (S experimental::regex_sets) This warning is emitted if you
5216 use the syntax S<C<(?[ ])>> in a regular expression.
5217 The details of this feature are subject to change.
5218 if you want to use it, but know that in doing so you
5219 are taking the risk of using an experimental feature which may
5220 change in a future Perl version, you can do this to silence the
5223 no warnings "experimental::regex_sets";
5225 =item The stat preceding %s wasn't an lstat
5227 (F) It makes no sense to test the current stat buffer for symbolic
5228 linkhood if the last stat that wrote to the stat buffer already went
5229 past the symlink to get to the real file. Use an actual filename
5232 =item The 'unique' attribute may only be applied to 'our' variables
5234 (F) This attribute was never supported on C<my> or C<sub> declarations.
5236 =item This Perl can't reset CRTL environ elements (%s)
5238 =item This Perl can't set CRTL environ elements (%s=%s)
5240 (W internal) Warnings peculiar to VMS. You tried to change or delete an
5241 element of the CRTL's internal environ array, but your copy of Perl
5242 wasn't built with a CRTL that contained the setenv() function. You'll
5243 need to rebuild Perl with a CRTL that does, or redefine
5244 F<PERL_ENV_TABLES> (see L<perlvms>) so that the environ array isn't the
5245 target of the change to
5246 %ENV which produced the warning.
5248 =item This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().
5250 (F) Something has attempted to use an internal API call which
5251 depends on Perl being compiled with the default support for randomized hash
5252 key traversal, but this Perl has been compiled without it. You should
5253 report this warning to the relevant upstream party, or recompile perl
5254 with default options.
5256 =item thread failed to start: %s
5258 (W threads)(S) The entry point function of threads->create() failed for some reason.
5260 =item times not implemented
5262 (F) Your version of the C library apparently doesn't do times(). I
5263 suspect you're not running on Unix.
5265 =item "-T" is on the #! line, it must also be used on the command line
5267 (X) The #! line (or local equivalent) in a Perl script contains
5268 the B<-T> option (or the B<-t> option), but Perl was not invoked with
5269 B<-T> in its command line. This is an error because, by the time
5270 Perl discovers a B<-T> in a script, it's too late to properly taint
5271 everything from the environment. So Perl gives up.
5273 If the Perl script is being executed as a command using the #!
5274 mechanism (or its local equivalent), this error can usually be
5275 fixed by editing the #! line so that the B<-%c> option is a part of
5276 Perl's first argument: e.g. change C<perl -n -%c> to C<perl -%c -n>.
5278 If the Perl script is being executed as C<perl scriptname>, then the
5279 B<-%c> option must appear on the command line: C<perl -%c scriptname>.
5281 =item To%s: illegal mapping '%s'
5283 (F) You tried to define a customized To-mapping for lc(), lcfirst,
5284 uc(), or ucfirst() (or their string-inlined versions), but you
5285 specified an illegal mapping.
5286 See L<perlunicode/"User-Defined Character Properties">.
5288 =item Too deeply nested ()-groups
5290 (F) Your template contains ()-groups with a ridiculously deep nesting level.
5292 =item Too few args to syscall
5294 (F) There has to be at least one argument to syscall() to specify the
5295 system call to call, silly dilly.
5297 =item Too late for "-%s" option
5299 (X) The #! line (or local equivalent) in a Perl script contains the
5300 B<-M>, B<-m> or B<-C> option.
5302 In the case of B<-M> and B<-m>, this is an error because those options
5303 are not intended for use inside scripts. Use the C<use> pragma instead.
5305 The B<-C> option only works if it is specified on the command line as
5306 well (with the same sequence of letters or numbers following). Either
5307 specify this option on the command line, or, if your system supports
5308 it, make your script executable and run it directly instead of passing
5311 =item Too late to run %s block
5313 (W void) A CHECK or INIT block is being defined during run time proper,
5314 when the opportunity to run them has already passed. Perhaps you are
5315 loading a file with C<require> or C<do> when you should be using C<use>
5316 instead. Or perhaps you should put the C<require> or C<do> inside a
5319 =item Too many args to syscall
5321 (F) Perl supports a maximum of only 14 args to syscall().
5323 =item Too many arguments for %s
5325 (F) The function requires fewer arguments than you specified.
5329 (A) You've accidentally run your script through B<csh> instead of Perl.
5330 Check the #! line, or manually feed your script into Perl yourself.
5334 (A) You've accidentally run your script through B<csh> instead of Perl.
5335 Check the #! line, or manually feed your script into Perl yourself.
5337 =item Trailing \ in regex m/%s/
5339 (F) The regular expression ends with an unbackslashed backslash.
5340 Backslash it. See L<perlre>.
5342 =item Trailing white-space in a charnames alias definition is deprecated
5344 (D deprecated) You defined a character name which ended in a space
5345 character. Remove the trailing space(s). Usually these names are
5346 defined in the C<:alias> import argument to C<use charnames>, but they
5347 could be defined by a translator installed into C<$^H{charnames}>.
5348 See L<charnames/CUSTOM ALIASES>.
5350 =item Transliteration pattern not terminated
5352 (F) The lexer couldn't find the interior delimiter of a tr/// or tr[][]
5353 or y/// or y[][] construct. Missing the leading C<$> from variables
5354 C<$tr> or C<$y> may cause this error.
5356 =item Transliteration replacement not terminated
5358 (F) The lexer couldn't find the final delimiter of a tr///, tr[][],
5359 y/// or y[][] construct.
5361 =item '%s' trapped by operation mask
5363 (F) You tried to use an operator from a Safe compartment in which it's
5364 disallowed. See L<Safe>.
5366 =item truncate not implemented
5368 (F) Your machine doesn't implement a file truncation mechanism that
5369 Configure knows about.
5371 =item Type of arg %d to &CORE::%s must be %s
5373 (F) The subroutine in question in the CORE package requires its argument
5374 to be a hard reference to data of the specified type. Overloading is
5375 ignored, so a reference to an object that is not the specified type, but
5376 nonetheless has overloading to handle it, will still not be accepted.
5378 =item Type of arg %d to %s must be %s (not %s)
5380 (F) This function requires the argument in that position to be of a
5381 certain type. Arrays must be @NAME or C<@{EXPR}>. Hashes must be
5382 %NAME or C<%{EXPR}>. No implicit dereferencing is allowed--use the
5383 {EXPR} forms as an explicit dereference. See L<perlref>.
5385 =item Type of argument to %s must be unblessed hashref or arrayref
5387 (F) You called C<keys>, C<values> or C<each> with a scalar argument that
5388 was not a reference to an unblessed hash or array.
5390 =item umask not implemented
5392 (F) Your machine doesn't implement the umask function and you tried to
5393 use it to restrict permissions for yourself (EXPR & 0700).
5395 =item Unbalanced context: %d more PUSHes than POPs
5397 (S internal) The exit code detected an internal inconsistency in how
5398 many execution contexts were entered and left.
5400 =item Unbalanced saves: %d more saves than restores
5402 (S internal) The exit code detected an internal inconsistency in how
5403 many values were temporarily localized.
5405 =item Unbalanced scopes: %d more ENTERs than LEAVEs
5407 (S internal) The exit code detected an internal inconsistency in how
5408 many blocks were entered and left.
5410 =item Unbalanced string table refcount: (%d) for "%s"
5412 (S internal) On exit, Perl found some strings remaining in the shared
5413 string table used for copy on write and for hash keys. The entries
5414 should have been freed, so this indicates a bug somewhere.
5416 =item Unbalanced tmps: %d more allocs than frees
5418 (S internal) The exit code detected an internal inconsistency in how
5419 many mortal scalars were allocated and freed.
5421 =item Undefined format "%s" called
5423 (F) The format indicated doesn't seem to exist. Perhaps it's really in
5424 another package? See L<perlform>.
5426 =item Undefined sort subroutine "%s" called
5428 (F) The sort comparison routine specified doesn't seem to exist.
5429 Perhaps it's in a different package? See L<perlfunc/sort>.
5431 =item Undefined subroutine &%s called
5433 (F) The subroutine indicated hasn't been defined, or if it was, it has
5434 since been undefined.
5436 =item Undefined subroutine called
5438 (F) The anonymous subroutine you're trying to call hasn't been defined,
5439 or if it was, it has since been undefined.
5441 =item Undefined subroutine in sort
5443 (F) The sort comparison routine specified is declared but doesn't seem
5444 to have been defined yet. See L<perlfunc/sort>.
5446 =item Undefined top format "%s" called
5448 (F) The format indicated doesn't seem to exist. Perhaps it's really in
5449 another package? See L<perlform>.
5451 =item Undefined value assigned to typeglob
5453 (W misc) An undefined value was assigned to a typeglob, a la
5454 C<*foo = undef>. This does nothing. It's possible that you really mean
5457 =item %s: Undefined variable
5459 (A) You've accidentally run your script through B<csh> instead of Perl.
5460 Check the #! line, or manually feed your script into Perl yourself.
5462 =item unexec of %s into %s failed!
5464 (F) The unexec() routine failed for some reason. See your local FSF
5465 representative, who probably put it there in the first place.
5467 =item Unexpected binary operator '%c' with no preceding operand in regex; marked by <-- HERE in m/%s/
5469 (F) You had something like this:
5473 where the C<"|"> is a binary operator with an operand on the right, but
5474 no operand on the left.
5476 =item Unexpected character in regex; marked by <-- HERE in m/%s/
5478 (F) You had something like this:
5482 Within C<(?[ ])>, no literal characters are allowed unless they are
5483 within an inner pair of square brackets, like
5487 Another possibility is that you forgot a backslash. Perl isn't smart
5488 enough to figure out what you really meant.
5490 =item Unexpected constant lvalue entersub entry via type/targ %d:%d
5492 (P) When compiling a subroutine call in lvalue context, Perl failed an
5493 internal consistency check. It encountered a malformed op tree.
5495 =item Unexpected exit %u
5497 (S) exit() was called or the script otherwise finished gracefully when
5498 C<PERL_EXIT_WARN> was set in C<PL_exit_flags>.
5500 =item Unexpected exit failure %u
5502 (S) An uncaught die() was called when C<PERL_EXIT_WARN> was set in
5505 =item Unexpected ')' in regex; marked by <-- HERE in m/%s/
5507 (F) You had something like this:
5509 (?[ ( \p{Digit} + ) ])
5511 The C<")"> is out-of-place. Something apparently was supposed to
5512 be combined with the digits, or the C<"+"> shouldn't be there, or
5513 something like that. Perl can't figure out what was intended.
5515 =item Unexpected '(' with no preceding operator in regex; marked by <-- HERE in m/%s/
5517 (F) You had something like this:
5519 (?[ \p{Digit} ( \p{Lao} + \p{Thai} ) ])
5521 There should be an operator before the C<"(">, as there's
5522 no indication as to how the digits are to be combined
5523 with the characters in the Lao and Thai scripts.
5525 =item Unicode non-character U+%X is illegal for open interchange
5527 (S utf8, nonchar) Certain codepoints, such as U+FFFE and U+FFFF, are
5528 defined by the Unicode standard to be non-characters. Those are
5529 legal codepoints, but are reserved for internal use; so, applications
5530 shouldn't attempt to exchange them. If you know what you are doing
5531 you can turn off this warning by C<no warnings 'nonchar';>.
5533 =item Unicode surrogate U+%X is illegal in UTF-8
5535 (S utf8, surrogate) You had a UTF-16 surrogate in a context where they are
5536 not considered acceptable. These code points, between U+D800 and
5537 U+DFFF (inclusive), are used by Unicode only for UTF-16. However, Perl
5538 internally allows all unsigned integer code points (up to the size limit
5539 available on your platform), including surrogates. But these can cause
5540 problems when being input or output, which is likely where this message
5541 came from. If you really really know what you are doing you can turn
5542 off this warning by C<no warnings 'surrogate';>.
5544 =item Unknown charname '%s'
5546 (F) The name you used inside C<\N{}> is unknown to Perl. Check the
5547 spelling. You can say C<use charnames ":loose"> to not have to be
5548 so precise about spaces, hyphens, and capitalization on standard Unicode
5549 names. (Any custom aliases that have been created must be specified
5550 exactly, regardless of whether C<:loose> is used or not.) This error may
5551 also happen if the C<\N{}> is not in the scope of the corresponding
5552 C<S<use charnames>>.
5556 (P) Perl was about to print an error message in C<$@>, but the C<$@> variable
5557 did not exist, even after an attempt to create it.
5559 =item Unknown open() mode '%s'
5561 (F) The second argument of 3-argument open() is not among the list
5562 of valid modes: C<< < >>, C<< > >>, C<<< >> >>>, C<< +< >>,
5563 C<< +> >>, C<<< +>> >>>, C<-|>, C<|->, C<< <& >>, C<< >& >>.
5565 =item Unknown PerlIO layer "%s"
5567 (W layer) An attempt was made to push an unknown layer onto the Perl I/O
5568 system. (Layers take care of transforming data between external and
5569 internal representations.) Note that some layers, such as C<mmap>,
5570 are not supported in all environments. If your program didn't
5571 explicitly request the failing operation, it may be the result of the
5572 value of the environment variable PERLIO.
5574 =item Unknown process %x sent message to prime_env_iter: %s
5576 (P) An error peculiar to VMS. Perl was reading values for %ENV before
5577 iterating over it, and someone else stuck a message in the stream of
5578 data Perl expected. Someone's very confused, or perhaps trying to
5579 subvert Perl's population of %ENV for nefarious purposes.
5581 =item Unknown regex modifier "%s"
5583 (F) Alphanumerics immediately following the closing delimiter
5584 of a regular expression pattern are interpreted by Perl as modifier
5585 flags for the regex. One of the ones you specified is invalid. One way
5586 this can happen is if you didn't put in white space between the end of
5587 the regex and a following alphanumeric operator:
5589 if ($a =~ /foo/and $bar == 3) { ... }
5591 The C<"a"> is a valid modifier flag, but the C<"n"> is not, and raises
5592 this error. Likely what was meant instead was:
5594 if ($a =~ /foo/ and $bar == 3) { ... }
5596 =item Unknown "re" subpragma '%s' (known ones are: %s)
5598 (W) You tried to use an unknown subpragma of the "re" pragma.
5600 =item Unknown switch condition (?(...)) in regex; marked by <-- HERE in m/%s/
5602 (F) The condition part of a (?(condition)if-clause|else-clause) construct
5603 is not known. The condition must be one of the following:
5605 (1) (2) ... true if 1st, 2nd, etc., capture matched
5606 (<NAME>) ('NAME') true if named capture matched
5607 (?=...) (?<=...) true if subpattern matches
5608 (?!...) (?<!...) true if subpattern fails to match
5609 (?{ CODE }) true if code returns a true value
5610 (R) true if evaluating inside recursion
5611 (R1) (R2) ... true if directly inside capture group 1, 2, etc.
5612 (R&NAME) true if directly inside named capture
5613 (DEFINE) always false; for defining named subpatterns
5615 The <-- HERE shows whereabouts in the regular expression the problem was
5616 discovered. See L<perlre>.
5618 =item Unknown Unicode option letter '%c'
5620 (F) You specified an unknown Unicode option. See L<perlrun> documentation
5621 of the C<-C> switch for the list of known options.
5623 =item Unknown Unicode option value %d
5625 (F) You specified an unknown Unicode option. See L<perlrun> documentation
5626 of the C<-C> switch for the list of known options.
5628 =item Unknown verb pattern '%s' in regex; marked by <-- HERE in m/%s/
5630 (F) You either made a typo or have incorrectly put a C<*> quantifier
5631 after an open brace in your pattern. Check the pattern and review
5632 L<perlre> for details on legal verb patterns.
5634 =item Unknown warnings category '%s'
5636 (F) An error issued by the C<warnings> pragma. You specified a warnings
5637 category that is unknown to perl at this point.
5639 Note that if you want to enable a warnings category registered by a
5640 module (e.g. C<use warnings 'File::Find'>), you must have loaded this
5643 =item Unmatched '[' in POSIX class in regex; marked by <-- HERE in m/%s/
5645 (F) You had something like this:
5649 That should be written:
5653 =item Unmatched '%c' in POSIX class in regex; marked by <-- HERE in m/%s/
5655 (F) You had something like this:
5659 There should be a second C<":">, like this:
5663 =item Unmatched [ in regex; marked by <-- HERE in m/%s/
5665 (F) The brackets around a character class must match. If you wish to
5666 include a closing bracket in a character class, backslash it or put it
5667 first. The <-- HERE shows whereabouts in the regular expression the
5668 problem was discovered. See L<perlre>.
5670 =item Unmatched ( in regex; marked by <-- HERE in m/%s/
5672 =item Unmatched ) in regex; marked by <-- HERE in m/%s/
5674 (F) Unbackslashed parentheses must always be balanced in regular
5675 expressions. If you're a vi user, the % key is valuable for finding
5676 the matching parenthesis. The <-- HERE shows whereabouts in the
5677 regular expression the problem was discovered. See L<perlre>.
5679 =item Unmatched right %s bracket
5681 (F) The lexer counted more closing curly or square brackets than opening
5682 ones, so you're probably missing a matching opening bracket. As a
5683 general rule, you'll find the missing one (so to speak) near the place
5684 you were last editing.
5686 =item Unquoted string "%s" may clash with future reserved word
5688 (W reserved) You used a bareword that might someday be claimed as a
5689 reserved word. It's best to put such a word in quotes, or capitalize it
5690 somehow, or insert an underbar into it. You might also declare it as a
5693 =item Unrecognized character %s; marked by <-- HERE after %s near column %d
5695 (F) The Perl parser has no idea what to do with the specified character
5696 in your Perl script (or eval) near the specified column. Perhaps you tried
5697 to run a compressed script, a binary program, or a directory as a Perl program.
5699 =item Unrecognized escape \%c in character class in regex; marked by <-- HERE in m/%s/
5701 (F) You used a backslash-character combination which is not
5702 recognized by Perl inside character classes. This is a fatal
5703 error when the character class is used within C<(?[ ])>.
5705 =item Unrecognized escape \%c in character class passed through in regex;
5706 marked by <-- HERE in m/%s/
5708 (W regexp) You used a backslash-character combination which is not
5709 recognized by Perl inside character classes. The character was
5710 understood literally, but this may change in a future version of Perl.
5711 The <-- HERE shows whereabouts in the regular expression the
5712 escape was discovered.
5714 =item Unrecognized escape \%c passed through
5716 (W misc) You used a backslash-character combination which is not
5717 recognized by Perl. The character was understood literally, but this may
5718 change in a future version of Perl.
5720 =item Unrecognized escape \%s passed through in regex; marked by <-- HERE in m/%s/
5722 (W regexp) You used a backslash-character combination which is not
5723 recognized by Perl. The character(s) were understood literally, but
5724 this may change in a future version of Perl. The <-- HERE shows
5725 whereabouts in the regular expression the escape was discovered.
5727 =item Unrecognized signal name "%s"
5729 (F) You specified a signal name to the kill() function that was not
5730 recognized. Say C<kill -l> in your shell to see the valid signal names
5733 =item Unrecognized switch: -%s (-h will show valid options)
5735 (F) You specified an illegal option to Perl. Don't do that. (If you
5736 think you didn't do that, check the #! line to see if it's supplying the
5737 bad switch on your behalf.)
5739 =item Unsuccessful %s on filename containing newline
5741 (W newline) A file operation was attempted on a filename, and that
5742 operation failed, PROBABLY because the filename contained a newline,
5743 PROBABLY because you forgot to chomp() it off. See L<perlfunc/chomp>.
5745 =item Unsupported directory function "%s" called
5747 (F) Your machine doesn't support opendir() and readdir().
5749 =item Unsupported function %s
5751 (F) This machine doesn't implement the indicated function, apparently.
5752 At least, Configure doesn't think so.
5754 =item Unsupported function fork
5756 (F) Your version of executable does not support forking.
5758 Note that under some systems, like OS/2, there may be different flavors
5759 of Perl executables, some of which may support fork, some not. Try
5760 changing the name you call Perl by to C<perl_>, C<perl__>, and so on.
5762 =item Unsupported script encoding %s
5764 (F) Your program file begins with a Unicode Byte Order Mark (BOM) which
5765 declares it to be in a Unicode encoding that Perl cannot read.
5767 =item Unsupported socket function "%s" called
5769 (F) Your machine doesn't support the Berkeley socket mechanism, or at
5770 least that's what Configure thought.
5772 =item Unterminated attribute list
5774 (F) The lexer found something other than a simple identifier at the
5775 start of an attribute, and it wasn't a semicolon or the start of a
5776 block. Perhaps you terminated the parameter list of the previous
5777 attribute too soon. See L<attributes>.
5779 =item Unterminated attribute parameter in attribute list
5781 (F) The lexer saw an opening (left) parenthesis character while parsing
5782 an attribute list, but the matching closing (right) parenthesis
5783 character was not found. You may need to add (or remove) a backslash
5784 character to get your parentheses to balance. See L<attributes>.
5786 =item Unterminated compressed integer
5788 (F) An argument to unpack("w",...) was incompatible with the BER
5789 compressed integer format and could not be converted to an integer.
5790 See L<perlfunc/pack>.
5792 =item Unterminated delimiter for here document
5794 (F) This message occurs when a here document label has an initial
5795 quotation mark but the final quotation mark is missing. Perhaps
5804 =item Unterminated \g... pattern in regex; marked by <-- HERE in m/%s/
5806 =item Unterminated \g{...} pattern in regex; marked by <-- HERE in m/%s/
5808 (F) In a regular expression, you had a C<\g> that wasn't followed by a
5809 proper group reference. In the case of C<\g{>, the closing brace is
5810 missing; otherwise the C<\g> must be followed by an integer. Fix the
5813 =item Unterminated <> operator
5815 (F) The lexer saw a left angle bracket in a place where it was expecting
5816 a term, so it's looking for the corresponding right angle bracket, and
5817 not finding it. Chances are you left some needed parentheses out
5818 earlier in the line, and you really meant a "less than".
5820 =item Unterminated verb pattern argument in regex; marked by <-- HERE in m/%s/
5822 (F) You used a pattern of the form C<(*VERB:ARG)> but did not terminate
5823 the pattern with a C<)>. Fix the pattern and retry.
5825 =item Unterminated verb pattern in regex; marked by <-- HERE in m/%s/
5827 (F) You used a pattern of the form C<(*VERB)> but did not terminate
5828 the pattern with a C<)>. Fix the pattern and retry.
5830 =item untie attempted while %d inner references still exist
5832 (W untie) A copy of the object returned from C<tie> (or C<tied>) was
5833 still valid when C<untie> was called.
5835 =item Usage: POSIX::%s(%s)
5837 (F) You called a POSIX function with incorrect arguments.
5838 See L<POSIX/FUNCTIONS> for more information.
5840 =item Usage: Win32::%s(%s)
5842 (F) You called a Win32 function with incorrect arguments.
5843 See L<Win32> for more information.
5845 =item $[ used in %s (did you mean $] ?)
5847 (W syntax) You used C<$[> in a comparison, such as:
5853 You probably meant to use C<$]> instead. C<$[> is the base for indexing
5854 arrays. C<$]> is the Perl version number in decimal.
5856 =item Useless assignment to a temporary
5858 (W misc) You assigned to an lvalue subroutine, but what
5859 the subroutine returned was a temporary scalar about to
5860 be discarded, so the assignment had no effect.
5862 =item Useless (?-%s) - don't use /%s modifier in regex; marked by <-- HERE in
5865 (W regexp) You have used an internal modifier such as (?-o) that has no
5866 meaning unless removed from the entire regexp:
5868 if ($string =~ /(?-o)$pattern/o) { ... }
5872 if ($string =~ /$pattern/) { ... }
5874 The <-- HERE shows whereabouts in the regular expression the problem was
5875 discovered. See L<perlre>.
5877 =item Useless localization of %s
5879 (W syntax) The localization of lvalues such as C<local($x=10)> is legal,
5880 but in fact the local() currently has no effect. This may change at
5881 some point in the future, but in the meantime such code is discouraged.
5883 =item Useless (?%s) - use /%s modifier in regex; marked by <-- HERE in m/%s/
5885 (W regexp) You have used an internal modifier such as (?o) that has no
5886 meaning unless applied to the entire regexp:
5888 if ($string =~ /(?o)$pattern/) { ... }
5892 if ($string =~ /$pattern/o) { ... }
5894 The <-- HERE shows whereabouts in the regular expression the problem was
5895 discovered. See L<perlre>.
5897 =item Useless use of /d modifier in transliteration operator
5899 (W misc) You have used the /d modifier where the searchlist has the
5900 same length as the replacelist. See L<perlop> for more information
5901 about the /d modifier.
5903 =item Useless use of '\'; doesn't escape metacharacter '%c'
5905 (D deprecated) You wrote a regular expression pattern something like
5911 s[foo\[a-z\]bar][baz]
5913 The interior braces, square brackets, and parentheses are treated as
5914 metacharacters even though they are backslashed; instead write:
5921 The backslashes have no effect when a regular expression pattern is
5922 delimited by C<{}>, C<[]>, or C<()>, which ordinarily are
5923 metacharacters, and the delimiters are also used, paired, within the
5924 interior of the pattern. It is planned that a future Perl release will
5925 change the meaning of constructs like these so that the backslashes
5926 will have an effect, so remove them from your code.
5928 =item Useless use of \E
5930 (W misc) You have a \E in a double-quotish string without a C<\U>,
5931 C<\L> or C<\Q> preceding it.
5933 =item Useless use of %s in void context
5935 (W void) You did something without a side effect in a context that does
5936 nothing with the return value, such as a statement that doesn't return a
5937 value from a block, or the left side of a scalar comma operator. Very
5938 often this points not to stupidity on your part, but a failure of Perl
5939 to parse your program the way you thought it would. For example, you'd
5940 get this if you mixed up your C precedence with Python precedence and
5945 when you meant to say
5947 ($one, $two) = (1, 2);
5949 Another common error is to use ordinary parentheses to construct a list
5950 reference when you should be using square or curly brackets, for
5955 when you should have said
5959 The square brackets explicitly turn a list value into a scalar value,
5960 while parentheses do not. So when a parenthesized list is evaluated in
5961 a scalar context, the comma is treated like C's comma operator, which
5962 throws away the left argument, which is not what you want. See
5963 L<perlref> for more on this.
5965 This warning will not be issued for numerical constants equal to 0 or 1
5966 since they are often used in statements like
5968 1 while sub_with_side_effects();
5970 String constants that would normally evaluate to 0 or 1 are warned
5973 =item Useless use of (?-p) in regex; marked by <-- HERE in m/%s/
5975 (W regexp) The C<p> modifier cannot be turned off once set. Trying to do
5978 =item Useless use of "re" pragma
5980 (W) You did C<use re;> without any arguments. That isn't very useful.
5982 =item Useless use of sort in scalar context
5984 (W void) You used sort in scalar context, as in :
5988 This is not very useful, and perl currently optimizes this away.
5990 =item Useless use of %s with no values
5992 (W syntax) You used the push() or unshift() function with no arguments
5993 apart from the array, like C<push(@x)> or C<unshift(@foo)>. That won't
5994 usually have any effect on the array, so is completely useless. It's
5995 possible in principle that push(@tied_array) could have some effect
5996 if the array is tied to a class which implements a PUSH method. If so,
5997 you can write it as C<push(@tied_array,())> to avoid this warning.
5999 =item "use" not allowed in expression
6001 (F) The "use" keyword is recognized and executed at compile time, and
6002 returns no useful value. See L<perlmod>.
6004 =item Use of assignment to $[ is deprecated
6006 (D deprecated) The C<$[> variable (index of the first element in an array)
6007 is deprecated. See L<perlvar/"$[">.
6009 =item Use of bare << to mean <<"" is deprecated
6011 (D deprecated) You are now encouraged to use the explicitly quoted
6012 form if you wish to use an empty line as the terminator of the here-document.
6014 =item Use of comma-less variable list is deprecated
6016 (D deprecated) The values you give to a format should be
6017 separated by commas, not just aligned on a line.
6019 =item Use of chdir('') or chdir(undef) as chdir() deprecated
6021 (D deprecated) chdir() with no arguments is documented to change to
6022 $ENV{HOME} or $ENV{LOGDIR}. chdir(undef) and chdir('') share this
6023 behavior, but that has been deprecated. In future versions they
6026 Be careful to check that what you pass to chdir() is defined and not
6027 blank, else you might find yourself in your home directory.
6029 =item Use of /c modifier is meaningless in s///
6031 (W regexp) You used the /c modifier in a substitution. The /c
6032 modifier is not presently meaningful in substitutions.
6034 =item Use of /c modifier is meaningless without /g
6036 (W regexp) You used the /c modifier with a regex operand, but didn't
6037 use the /g modifier. Currently, /c is meaningful only when /g is
6038 used. (This may change in the future.)
6040 =item Use of each() on hash after insertion without resetting hash iterator results in undefined behavior
6042 (S internal) The behavior of C<each()> after insertion is undefined;
6043 it may skip items, or visit items more than once. Consider using
6044 C<keys()> instead of C<each()>.
6046 =item Use of := for an empty attribute list is not allowed
6048 (F) The construction C<my $x := 42> used to parse as equivalent to
6049 C<my $x : = 42> (applying an empty attribute list to C<$x>).
6050 This construct was deprecated in 5.12.0, and has now been made a syntax
6051 error, so C<:=> can be reclaimed as a new operator in the future.
6053 If you need an empty attribute list, for example in a code generator, add
6054 a space before the C<=>.
6056 =item Use of freed value in iteration
6058 (F) Perhaps you modified the iterated array within the loop?
6059 This error is typically caused by code like the following:
6062 @a = () for (1,2,@a);
6064 You are not supposed to modify arrays while they are being iterated over.
6065 For speed and efficiency reasons, Perl internally does not do full
6066 reference-counting of iterated items, hence deleting such an item in the
6067 middle of an iteration causes Perl to see a freed value.
6069 =item Use of *glob{FILEHANDLE} is deprecated
6071 (D deprecated) You are now encouraged to use the shorter *glob{IO} form
6072 to access the filehandle slot within a typeglob.
6074 =item Use of /g modifier is meaningless in split
6076 (W regexp) You used the /g modifier on the pattern for a C<split>
6077 operator. Since C<split> always tries to match the pattern
6078 repeatedly, the C</g> has no effect.
6080 =item Use of "goto" to jump into a construct is deprecated
6082 (D deprecated) Using C<goto> to jump from an outer scope into an inner
6083 scope is deprecated and should be avoided.
6085 =item Use of inherited AUTOLOAD for non-method %s() is deprecated
6087 (D deprecated) As an (ahem) accidental feature, C<AUTOLOAD>
6088 subroutines are looked up as methods (using the C<@ISA> hierarchy)
6089 even when the subroutines to be autoloaded were called as plain
6090 functions (e.g. C<Foo::bar()>), not as methods (e.g. C<< Foo->bar() >> or
6091 C<< $obj->bar() >>).
6093 This bug will be rectified in future by using method lookup only for
6094 methods' C<AUTOLOAD>s. However, there is a significant base of existing
6095 code that may be using the old behavior. So, as an interim step, Perl
6096 currently issues an optional warning when non-methods use inherited
6099 The simple rule is: Inheritance will not work when autoloading
6100 non-methods. The simple fix for old code is: In any module that used
6101 to depend on inheriting C<AUTOLOAD> for non-methods from a base class
6102 named C<BaseClass>, execute C<*AUTOLOAD = \&BaseClass::AUTOLOAD> during
6105 In code that currently says C<use AutoLoader; @ISA = qw(AutoLoader);>
6106 you should remove AutoLoader from @ISA and change C<use AutoLoader;> to
6107 C<use AutoLoader 'AUTOLOAD';>.
6109 =item Use of literal control characters in variable names is deprecated
6111 (D deprecated) Using literal control characters in the source to refer
6112 to the ^FOO variables, like C<$^X> and C<${^GLOBAL_PHASE}> is now
6113 deprecated. This only affects code like C<$\cT>, where \cT is a control in
6114 the source code: C<${"\cT"}> and C<$^T> remain valid.
6116 =item Use of %s in printf format not supported
6118 (F) You attempted to use a feature of printf that is accessible from
6119 only C. This usually means there's a better way to do it in Perl.
6121 =item Use of %s is deprecated
6123 (D deprecated) The construct indicated is no longer recommended for use,
6124 generally because there's a better way to do it, and also because the
6125 old way has bad side effects.
6127 =item Use of -l on filehandle%s
6129 (W io) A filehandle represents an opened file, and when you opened the file
6130 it already went past any symlink you are presumably trying to look for.
6131 The operation returned C<undef>. Use a filename instead.
6133 =item Use of my $_ is experimental
6135 (S experimental::lexical_topic) Lexical $_ is an experimental feature and
6136 its behavior may change or even be removed in any future release of perl.
6137 See the explanation under L<perlvar/$_>.
6139 =item Use of %s on a handle without * is deprecated
6141 (D deprecated) You used C<tie>, C<tied> or C<untie> on a scalar but that scalar
6142 happens to hold a typeglob, which means its filehandle will be tied. If
6143 you mean to tie a handle, use an explicit * as in C<tie *$handle>.
6145 This was a long-standing bug that was removed in Perl 5.16, as there was
6146 no way to tie the scalar itself when it held a typeglob, and no way to
6147 untie a scalar that had had a typeglob assigned to it. If you see this
6148 message, you must be using an older version.
6150 =item Use of ?PATTERN? without explicit operator is deprecated
6152 (D deprecated) You have written something like C<?\w?>, for a regular
6153 expression that matches only once. Starting this term directly with
6154 the question mark delimiter is now deprecated, so that the question mark
6155 will be available for use in new operators in the future. Write C<m?\w?>
6156 instead, explicitly using the C<m> operator: the question mark delimiter
6157 still invokes match-once behaviour.
6159 =item Use of reference "%s" as array index
6161 (W misc) You tried to use a reference as an array index; this probably
6162 isn't what you mean, because references in numerical context tend
6163 to be huge numbers, and so usually indicates programmer error.
6165 If you really do mean it, explicitly numify your reference, like so:
6166 C<$array[0+$ref]>. This warning is not given for overloaded objects,
6167 however, because you can overload the numification and stringification
6168 operators and then you presumably know what you are doing.
6170 =item Use of state $_ is experimental
6172 (S experimental::lexical_topic) Lexical $_ is an experimental feature and
6173 its behavior may change or even be removed in any future release of perl.
6174 See the explanation under L<perlvar/$_>.
6176 =item Use of tainted arguments in %s is deprecated
6178 (W taint, deprecated) You have supplied C<system()> or C<exec()> with multiple
6179 arguments and at least one of them is tainted. This used to be allowed
6180 but will become a fatal error in a future version of perl. Untaint your
6181 arguments. See L<perlsec>.
6183 =item Use of uninitialized value%s
6185 (W uninitialized) An undefined value was used as if it were already
6186 defined. It was interpreted as a "" or a 0, but maybe it was a mistake.
6187 To suppress this warning assign a defined value to your variables.
6189 To help you figure out what was undefined, perl will try to tell you
6190 the name of the variable (if any) that was undefined. In some cases
6191 it cannot do this, so it also tells you what operation you used the
6192 undefined value in. Note, however, that perl optimizes your program
6193 and the operation displayed in the warning may not necessarily appear
6194 literally in your program. For example, C<"that $foo"> is usually
6195 optimized into C<"that " . $foo>, and the warning will refer to the
6196 C<concatenation (.)> operator, even though there is no C<.> in
6199 =item Use \x{...} for more than two hex characters in regex; marked by <-- HERE in m/%s/
6201 (F) In a regular expression, you said something like
6205 Perl isn't sure if you meant this
6209 or if you meant this
6211 (?[ [ \x{BE} E F ] ])
6213 You need to add either braces or blanks to disambiguate.
6215 =item Using a hash as a reference is deprecated
6217 (D deprecated) You tried to use a hash as a reference, as in
6218 C<< %foo->{"bar"} >> or C<< %$ref->{"hello"} >>. Versions of perl <= 5.6.1
6219 used to allow this syntax, but shouldn't have. It is now
6220 deprecated, and will be removed in a future version.
6222 =item Using an array as a reference is deprecated
6224 (D deprecated) You tried to use an array as a reference, as in
6225 C<< @foo->[23] >> or C<< @$ref->[99] >>. Versions of perl <= 5.6.1 used to
6226 allow this syntax, but shouldn't have. It is now deprecated,
6227 and will be removed in a future version.
6229 =item Using just the first character returned by \N{} in character class in
6230 regex; marked by <-- HERE in m/%s/
6232 (W regexp) A charnames handler may return a sequence of more than one
6233 character. Currently all but the first one are discarded when used in
6234 a regular expression pattern bracketed character class.
6236 =item Using !~ with %s doesn't make sense
6238 (F) Using the C<!~> operator with C<s///r>, C<tr///r> or C<y///r> is
6239 currently reserved for future use, as the exact behaviour has not
6240 been decided. (Simply returning the boolean opposite of the
6241 modified string is usually not particularly useful.)
6243 =item UTF-16 surrogate U+%X
6245 (S utf8, surrogate) You had a UTF-16 surrogate in a context where they are
6246 not considered acceptable. These code points, between U+D800 and
6247 U+DFFF (inclusive), are used by Unicode only for UTF-16. However, Perl
6248 internally allows all unsigned integer code points (up to the size limit
6249 available on your platform), including surrogates. But these can cause
6250 problems when being input or output, which is likely where this message
6251 came from. If you really really know what you are doing you can turn
6252 off this warning by C<no warnings 'surrogate';>.
6254 =item Value of %s can be "0"; test with defined()
6256 (W misc) In a conditional expression, you used <HANDLE>, <*> (glob),
6257 C<each()>, or C<readdir()> as a boolean value. Each of these constructs
6258 can return a value of "0"; that would make the conditional expression
6259 false, which is probably not what you intended. When using these
6260 constructs in conditional expressions, test their values with the
6261 C<defined> operator.
6263 =item Value of CLI symbol "%s" too long
6265 (W misc) A warning peculiar to VMS. Perl tried to read the value of an
6266 %ENV element from a CLI symbol table, and found a resultant string
6267 longer than 1024 characters. The return value has been truncated to
6270 =item Variable "%s" is not available
6272 (W closure) During compilation, an inner named subroutine or eval is
6273 attempting to capture an outer lexical that is not currently available.
6274 This can happen for one of two reasons. First, the outer lexical may be
6275 declared in an outer anonymous subroutine that has not yet been created.
6276 (Remember that named subs are created at compile time, while anonymous
6277 subs are created at run-time.) For example,
6279 sub { my $a; sub f { $a } }
6281 At the time that f is created, it can't capture the current value of $a,
6282 since the anonymous subroutine hasn't been created yet. Conversely,
6283 the following won't give a warning since the anonymous subroutine has by
6284 now been created and is live:
6286 sub { my $a; eval 'sub f { $a }' }->();
6288 The second situation is caused by an eval accessing a variable that has
6289 gone out of scope, for example,
6297 Here, when the '$a' in the eval is being compiled, f() is not currently being
6298 executed, so its $a is not available for capture.
6300 =item Variable "%s" is not imported%s
6302 (S misc) With "use strict" in effect, you referred to a global variable
6303 that you apparently thought was imported from another module, because
6304 something else of the same name (usually a subroutine) is exported by
6305 that module. It usually means you put the wrong funny character on the
6306 front of your variable.
6308 =item Variable length lookbehind not implemented in regex m/%s/
6310 (F) Lookbehind is allowed only for subexpressions whose length is fixed and
6311 known at compile time. See L<perlre>.
6313 =item "%s" variable %s masks earlier declaration in same %s
6315 (W misc) A "my", "our" or "state" variable has been redeclared in the
6316 current scope or statement, effectively eliminating all access to the
6317 previous instance. This is almost always a typographical error. Note
6318 that the earlier variable will still exist until the end of the scope
6319 or until all closure references to it are destroyed.
6321 =item Variable syntax
6323 (A) You've accidentally run your script through B<csh> instead
6324 of Perl. Check the #! line, or manually feed your script into
6327 =item Variable "%s" will not stay shared
6329 (W closure) An inner (nested) I<named> subroutine is referencing a
6330 lexical variable defined in an outer named subroutine.
6332 When the inner subroutine is called, it will see the value of
6333 the outer subroutine's variable as it was before and during the *first*
6334 call to the outer subroutine; in this case, after the first call to the
6335 outer subroutine is complete, the inner and outer subroutines will no
6336 longer share a common value for the variable. In other words, the
6337 variable will no longer be shared.
6339 This problem can usually be solved by making the inner subroutine
6340 anonymous, using the C<sub {}> syntax. When inner anonymous subs that
6341 reference variables in outer subroutines are created, they
6342 are automatically rebound to the current values of such variables.
6344 =item vector argument not supported with alpha versions
6346 (S printf) The %vd (s)printf format does not support version objects
6349 =item Verb pattern '%s' has a mandatory argument in regex; marked by <-- HERE
6352 (F) You used a verb pattern that requires an argument. Supply an
6353 argument or check that you are using the right verb.
6355 =item Verb pattern '%s' may not have an argument in regex; marked by <-- HERE
6358 (F) You used a verb pattern that is not allowed an argument. Remove the
6359 argument or check that you are using the right verb.
6361 =item Version number must be a constant number
6363 (P) The attempt to translate a C<use Module n.n LIST> statement into
6364 its equivalent C<BEGIN> block found an internal inconsistency with
6367 =item Version string '%s' contains invalid data; ignoring: '%s'
6369 (W misc) The version string contains invalid characters at the end, which
6372 =item Warning: something's wrong
6374 (W) You passed warn() an empty string (the equivalent of C<warn "">) or
6375 you called it with no args and C<$@> was empty.
6377 =item Warning: unable to close filehandle %s properly
6379 (S) The implicit close() done by an open() got an error indication on
6380 the close(). This usually indicates your file system ran out of disk
6383 =item Warning: Use of "%s" without parentheses is ambiguous
6385 (S ambiguous) You wrote a unary operator followed by something that
6386 looks like a binary operator that could also have been interpreted as a
6387 term or unary operator. For instance, if you know that the rand
6388 function has a default argument of 1.0, and you write
6392 you may THINK you wrote the same thing as
6396 but in actual fact, you got
6400 So put in parentheses to say what you really mean.
6402 =item when is experimental
6404 (S experimental::smartmatch) C<when> depends on smartmatch, which is
6405 experimental. Additionally, it has several special cases that may
6406 not be immediately obvious, and their behavior may change or
6407 even be removed in any future release of perl. See the explanation
6408 under L<perlsyn/Experimental Details on given and when>.
6410 =item Wide character in %s
6412 (S utf8) Perl met a wide character (>255) when it wasn't expecting
6413 one. This warning is by default on for I/O (like print). The easiest
6414 way to quiet this warning is simply to add the C<:utf8> layer to the
6415 output, e.g. C<binmode STDOUT, ':utf8'>. Another way to turn off the
6416 warning is to add C<no warnings 'utf8';> but that is often closer to
6417 cheating. In general, you are supposed to explicitly mark the
6418 filehandle with an encoding, see L<open> and L<perlfunc/binmode>.
6420 =item Within []-length '%c' not allowed
6422 (F) The count in the (un)pack template may be replaced by C<[TEMPLATE]>
6423 only if C<TEMPLATE> always matches the same amount of packed bytes that
6424 can be determined from the template alone. This is not possible if
6425 it contains any of the codes @, /, U, u, w or a *-length. Redesign
6428 =item write() on closed filehandle %s
6430 (W closed) The filehandle you're writing to got itself closed sometime
6431 before now. Check your control flow.
6433 =item %s "\x%X" does not map to Unicode
6435 (S utf8) When reading in different encodings, Perl tries to
6436 map everything into Unicode characters. The bytes you read
6437 in are not legal in this encoding. For example
6439 utf8 "\xE4" does not map to Unicode
6441 if you try to read in the a-diaereses Latin-1 as UTF-8.
6443 =item 'X' outside of string
6445 (F) You had a (un)pack template that specified a relative position before
6446 the beginning of the string being (un)packed. See L<perlfunc/pack>.
6448 =item 'x' outside of string in unpack
6450 (F) You had a pack template that specified a relative position after
6451 the end of the string being unpacked. See L<perlfunc/pack>.
6453 =item YOU HAVEN'T DISABLED SET-ID SCRIPTS IN THE KERNEL YET!
6455 (F) And you probably never will, because you probably don't have the
6456 sources to your kernel, and your vendor probably doesn't give a rip
6457 about what you want. Your best bet is to put a setuid C wrapper around
6460 =item You need to quote "%s"
6462 (W syntax) You assigned a bareword as a signal handler name.
6463 Unfortunately, you already have a subroutine of that name declared,
6464 which means that Perl 5 will try to call the subroutine when the
6465 assignment is executed, which is probably not what you want. (If it IS
6466 what you want, put an & in front.)
6468 =item Your random numbers are not that random
6470 (F) When trying to initialize the random seed for hashes, Perl could
6471 not get any randomness out of your system. This usually indicates
6472 Something Very Wrong.
6478 L<warnings>, L<perllexwarn>, L<diagnostics>.