3 perldiag - various Perl diagnostics
7 These messages are classified as follows (listed in increasing order of
10 (W) A warning (optional).
11 (D) A deprecation (enabled by default).
12 (S) A severe warning (enabled by default).
13 (F) A fatal error (trappable).
14 (P) An internal error you should never see (trappable).
15 (X) A very fatal error (nontrappable).
16 (A) An alien error message (not generated by Perl).
18 The majority of messages from the first three classifications above
19 (W, D & S) can be controlled using the C<warnings> pragma.
21 If a message can be controlled by the C<warnings> pragma, its warning
22 category is included with the classification letter in the description
23 below. E.g. C<(W closed)> means a warning in the C<closed> category.
25 Optional warnings are enabled by using the C<warnings> pragma or the B<-w>
26 and B<-W> switches. Warnings may be captured by setting C<$SIG{__WARN__}>
27 to a reference to a routine that will be called on each warning instead
28 of printing it. See L<perlvar>.
30 Severe warnings are always enabled, unless they are explicitly disabled
31 with the C<warnings> pragma or the B<-X> switch.
33 Trappable errors may be trapped using the eval operator. See
34 L<perlfunc/eval>. In almost all cases, warnings may be selectively
35 disabled or promoted to fatal errors using the C<warnings> pragma.
38 The messages are in alphabetical order, without regard to upper or
39 lower-case. Some of these messages are generic. Spots that vary are
40 denoted with a %s or other printf-style escape. These escapes are
41 ignored by the alphabetical order, as are all characters other than
42 letters. To look up your message, just ignore anything that is not a
47 =item accept() on closed socket %s
49 (W closed) You tried to do an accept on a closed socket. Did you forget
50 to check the return value of your socket() call? See
53 =item Aliasing via reference is experimental
55 (S experimental::refaliasing) This warning is emitted if you use
56 a reference constructor on the left-hand side of an assignment to
57 alias one variable to another. Simply suppress the warning if you
58 want to use the feature, but know that in doing so you are taking
59 the risk of using an experimental feature which may change or be
60 removed in a future Perl version:
62 no warnings "experimental::refaliasing";
63 use feature "refaliasing";
66 =item Allocation too large: %x
68 (X) You can't allocate more than 64K on an MS-DOS machine.
70 =item '%c' allowed only after types %s in %s
72 (F) The modifiers '!', '<' and '>' are allowed in pack() or unpack() only
73 after certain types. See L<perlfunc/pack>.
75 =item Ambiguous call resolved as CORE::%s(), qualify as such or use &
77 (W ambiguous) A subroutine you have declared has the same name as a Perl
78 keyword, and you have used the name without qualification for calling
79 one or the other. Perl decided to call the builtin because the
80 subroutine is not imported.
82 To force interpretation as a subroutine call, either put an ampersand
83 before the subroutine name, or qualify the name with its package.
84 Alternatively, you can import the subroutine (or pretend that it's
85 imported with the C<use subs> pragma).
87 To silently interpret it as the Perl operator, use the C<CORE::> prefix
88 on the operator (e.g. C<CORE::log($x)>) or declare the subroutine
89 to be an object method (see L<perlsub/"Subroutine Attributes"> or
92 =item Ambiguous range in transliteration operator
94 (F) You wrote something like C<tr/a-z-0//> which doesn't mean anything at
95 all. To include a C<-> character in a transliteration, put it either
96 first or last. (In the past, C<tr/a-z-0//> was synonymous with
97 C<tr/a-y//>, which was probably not what you would have expected.)
99 =item Ambiguous use of %s resolved as %s
101 (S ambiguous) You said something that may not be interpreted the way
102 you thought. Normally it's pretty easy to disambiguate it by supplying
103 a missing quote, operator, parenthesis pair or declaration.
105 =item Ambiguous use of -%s resolved as -&%s()
107 (S ambiguous) You wrote something like C<-foo>, which might be the
108 string C<"-foo">, or a call to the function C<foo>, negated. If you meant
109 the string, just write C<"-foo">. If you meant the function call,
112 =item Ambiguous use of %c resolved as operator %c
114 (S ambiguous) C<%>, C<&>, and C<*> are both infix operators (modulus,
115 bitwise and, and multiplication) I<and> initial special characters
116 (denoting hashes, subroutines and typeglobs), and you said something
117 like C<*foo * foo> that might be interpreted as either of them. We
118 assumed you meant the infix operator, but please try to make it more
119 clear -- in the example given, you might write C<*foo * foo()> if you
120 really meant to multiply a glob by the result of calling a function.
122 =item Ambiguous use of %c{%s} resolved to %c%s
124 (W ambiguous) You wrote something like C<@{foo}>, which might be
125 asking for the variable C<@foo>, or it might be calling a function
126 named foo, and dereferencing it as an array reference. If you wanted
127 the variable, you can just write C<@foo>. If you wanted to call the
128 function, write C<@{foo()}> ... or you could just not have a variable
129 and a function with the same name, and save yourself a lot of trouble.
131 =item Ambiguous use of %c{%s[...]} resolved to %c%s[...]
133 =item Ambiguous use of %c{%s{...}} resolved to %c%s{...}
135 (W ambiguous) You wrote something like C<${foo[2]}> (where foo represents
136 the name of a Perl keyword), which might be looking for element number
137 2 of the array named C<@foo>, in which case please write C<$foo[2]>, or you
138 might have meant to pass an anonymous arrayref to the function named
139 foo, and then do a scalar deref on the value it returns. If you meant
140 that, write C<${foo([2])}>.
142 In regular expressions, the C<${foo[2]}> syntax is sometimes necessary
143 to disambiguate between array subscripts and character classes.
144 C</$length[2345]/>, for instance, will be interpreted as C<$length> followed
145 by the character class C<[2345]>. If an array subscript is what you
146 want, you can avoid the warning by changing C</${length[2345]}/> to the
147 unsightly C</${\$length[2345]}/>, by renaming your array to something
148 that does not coincide with a built-in keyword, or by simply turning
149 off warnings with C<no warnings 'ambiguous';>.
151 =item '|' and '<' may not both be specified on command line
153 (F) An error peculiar to VMS. Perl does its own command line
154 redirection, and found that STDIN was a pipe, and that you also tried to
155 redirect STDIN using '<'. Only one STDIN stream to a customer, please.
157 =item '|' and '>' may not both be specified on command line
159 (F) An error peculiar to VMS. Perl does its own command line
160 redirection, and thinks you tried to redirect stdout both to a file and
161 into a pipe to another command. You need to choose one or the other,
162 though nothing's stopping you from piping into a program or Perl script
163 which 'splits' output into two streams, such as
165 open(OUT,">$ARGV[0]") or die "Can't write to $ARGV[0]: $!";
172 =item Applying %s to %s will act on scalar(%s)
174 (W misc) The pattern match (C<//>), substitution (C<s///>), and
175 transliteration (C<tr///>) operators work on scalar values. If you apply
176 one of them to an array or a hash, it will convert the array or hash to
177 a scalar value (the length of an array, or the population info of a
178 hash) and then work on that scalar value. This is probably not what
179 you meant to do. See L<perlfunc/grep> and L<perlfunc/map> for
182 =item Arg too short for msgsnd
184 (F) msgsnd() requires a string at least as long as sizeof(long).
186 =item Argument "%s" isn't numeric%s
188 (W numeric) The indicated string was fed as an argument to an operator
189 that expected a numeric value instead. If you're fortunate the message
190 will identify which operator was so unfortunate.
192 =item Argument list not closed for PerlIO layer "%s"
194 (W layer) When pushing a layer with arguments onto the Perl I/O
195 system you forgot the ) that closes the argument list. (Layers
196 take care of transforming data between external and internal
197 representations.) Perl stopped parsing the layer list at this
198 point and did not attempt to push this layer. If your program
199 didn't explicitly request the failing operation, it may be the
200 result of the value of the environment variable PERLIO.
202 =item Argument "%s" treated as 0 in increment (++)
204 (W numeric) The indicated string was fed as an argument to the C<++>
205 operator which expects either a number or a string matching
206 C</^[a-zA-Z]*[0-9]*\z/>. See L<perlop/Auto-increment and
207 Auto-decrement> for details.
209 =item assertion botched: %s
211 (X) The malloc package that comes with Perl had an internal failure.
213 =item Assertion %s failed: file "%s", line %d
215 (X) A general assertion failed. The file in question must be examined.
217 =item Assigned value is not a reference
219 (F) You tried to assign something that was not a reference to an lvalue
220 reference (e.g., C<\$x = $y>). If you meant to make $x an alias to $y, use
223 =item Assigned value is not %s reference
225 (F) You tried to assign a reference to a reference constructor, but the
226 two references were not of the same type. You cannot alias a scalar to
227 an array, or an array to a hash; the two types must match.
232 \$x = $y; # error; did you mean \$y?
234 =item Assigning non-zero to $[ is no longer possible
236 (F) When the "array_base" feature is disabled (e.g., under C<use v5.16;>)
237 the special variable C<$[>, which is deprecated, is now a fixed zero value.
239 =item Assignment to both a list and a scalar
241 (F) If you assign to a conditional operator, the 2nd and 3rd arguments
242 must either both be scalars or both be lists. Otherwise Perl won't
243 know which context to supply to the right side.
245 =item <> at require-statement should be quotes
247 (F) You wrote C<< require <file> >> when you should have written
250 =item Attempt to access disallowed key '%s' in a restricted hash
252 (F) The failing code has attempted to get or set a key which is not in
253 the current set of allowed keys of a restricted hash.
255 =item Attempt to bless into a freed package
257 (F) You wrote C<bless $foo> with one argument after somehow causing
258 the current package to be freed. Perl cannot figure out what to
259 do, so it throws up in hands in despair.
261 =item Attempt to bless into a reference
263 (F) The CLASSNAME argument to the bless() operator is expected to be
264 the name of the package to bless the resulting object into. You've
265 supplied instead a reference to something: perhaps you wrote
271 bless $self, ref($proto) || $proto;
273 If you actually want to bless into the stringified version
274 of the reference supplied, you need to stringify it yourself, for
277 bless $self, "$proto";
279 =item Attempt to clear deleted array
281 (S debugging) An array was assigned to when it was being freed.
282 Freed values are not supposed to be visible to Perl code. This
283 can also happen if XS code calls C<av_clear> from a custom magic
284 callback on the array.
286 =item Attempt to delete disallowed key '%s' from a restricted hash
288 (F) The failing code attempted to delete from a restricted hash a key
289 which is not in its key set.
291 =item Attempt to delete readonly key '%s' from a restricted hash
293 (F) The failing code attempted to delete a key whose value has been
294 declared readonly from a restricted hash.
296 =item Attempt to free non-arena SV: 0x%x
298 (S internal) All SV objects are supposed to be allocated from arenas
299 that will be garbage collected on exit. An SV was discovered to be
300 outside any of those arenas.
302 =item Attempt to free nonexistent shared string '%s'%s
304 (S internal) Perl maintains a reference-counted internal table of
305 strings to optimize the storage and access of hash keys and other
306 strings. This indicates someone tried to decrement the reference count
307 of a string that can no longer be found in the table.
309 =item Attempt to free temp prematurely: SV 0x%x
311 (S debugging) Mortalized values are supposed to be freed by the
312 free_tmps() routine. This indicates that something else is freeing the
313 SV before the free_tmps() routine gets a chance, which means that the
314 free_tmps() routine will be freeing an unreferenced scalar when it does
317 =item Attempt to free unreferenced glob pointers
319 (S internal) The reference counts got screwed up on symbol aliases.
321 =item Attempt to free unreferenced scalar: SV 0x%x
323 (S internal) Perl went to decrement the reference count of a scalar to
324 see if it would go to 0, and discovered that it had already gone to 0
325 earlier, and should have been freed, and in fact, probably was freed.
326 This could indicate that SvREFCNT_dec() was called too many times, or
327 that SvREFCNT_inc() was called too few times, or that the SV was
328 mortalized when it shouldn't have been, or that memory has been
331 =item Attempt to pack pointer to temporary value
333 (W pack) You tried to pass a temporary value (like the result of a
334 function, or a computed expression) to the "p" pack() template. This
335 means the result contains a pointer to a location that could become
336 invalid anytime, even before the end of the current statement. Use
337 literals or global values as arguments to the "p" pack() template to
340 =item Attempt to reload %s aborted.
342 (F) You tried to load a file with C<use> or C<require> that failed to
343 compile once already. Perl will not try to compile this file again
344 unless you delete its entry from %INC. See L<perlfunc/require> and
347 =item Attempt to set length of freed array
349 (W misc) You tried to set the length of an array which has
350 been freed. You can do this by storing a reference to the
351 scalar representing the last index of an array and later
352 assigning through that reference. For example
354 $r = do {my @a; \$#a};
357 =item Attempt to use reference as lvalue in substr
359 (W substr) You supplied a reference as the first argument to substr()
360 used as an lvalue, which is pretty strange. Perhaps you forgot to
361 dereference it first. See L<perlfunc/substr>.
363 =item Attribute "locked" is deprecated
365 (D deprecated) You have used the attributes pragma to modify the
366 "locked" attribute on a code reference. The :locked attribute is
367 obsolete, has had no effect since 5005 threads were removed, and
368 will be removed in a future release of Perl 5.
370 =item Attribute prototype(%s) discards earlier prototype attribute in same sub
372 (W misc) A sub was declared as sub foo : prototype(A) : prototype(B) {}, for
373 example. Since each sub can only have one prototype, the earlier
374 declaration(s) are discarded while the last one is applied.
376 =item Attribute "unique" is deprecated
378 (D deprecated) You have used the attributes pragma to modify
379 the "unique" attribute on an array, hash or scalar reference.
380 The :unique attribute has had no effect since Perl 5.8.8, and
381 will be removed in a future release of Perl 5.
383 =item av_reify called on tied array
385 (S debugging) This indicates that something went wrong and Perl got I<very>
386 confused about C<@_> or C<@DB::args> being tied.
388 =item Bad arg length for %s, is %u, should be %d
390 (F) You passed a buffer of the wrong size to one of msgctl(), semctl()
391 or shmctl(). In C parlance, the correct sizes are, respectively,
392 S<sizeof(struct msqid_ds *)>, S<sizeof(struct semid_ds *)>, and
393 S<sizeof(struct shmid_ds *)>.
395 =item Bad evalled substitution pattern
397 (F) You've used the C</e> switch to evaluate the replacement for a
398 substitution, but perl found a syntax error in the code to evaluate,
399 most likely an unexpected right brace '}'.
401 =item Bad filehandle: %s
403 (F) A symbol was passed to something wanting a filehandle, but the
404 symbol has no filehandle associated with it. Perhaps you didn't do an
405 open(), or did it in another package.
407 =item Bad free() ignored
409 (S malloc) An internal routine called free() on something that had never
410 been malloc()ed in the first place. Mandatory, but can be disabled by
411 setting environment variable C<PERL_BADFREE> to 0.
413 This message can be seen quite often with DB_File on systems with "hard"
414 dynamic linking, like C<AIX> and C<OS/2>. It is a bug of C<Berkeley DB>
415 which is left unnoticed if C<DB> uses I<forgiving> system malloc().
419 (P) One of the internal hash routines was passed a null HV pointer.
421 =item Badly placed ()'s
423 (A) You've accidentally run your script through B<csh> instead
424 of Perl. Check the #! line, or manually feed your script into
427 =item Bad name after %s
429 (F) You started to name a symbol by using a package prefix, and then
430 didn't finish the symbol. In particular, you can't interpolate outside
439 $sym = "mypack::$var";
441 =item Bad plugin affecting keyword '%s'
443 (F) An extension using the keyword plugin mechanism violated the
446 =item Bad realloc() ignored
448 (S malloc) An internal routine called realloc() on something that
449 had never been malloc()ed in the first place. Mandatory, but can
450 be disabled by setting the environment variable C<PERL_BADFREE> to 1.
452 =item Bad symbol for array
454 (P) An internal request asked to add an array entry to something that
455 wasn't a symbol table entry.
457 =item Bad symbol for dirhandle
459 (P) An internal request asked to add a dirhandle entry to something
460 that wasn't a symbol table entry.
462 =item Bad symbol for filehandle
464 (P) An internal request asked to add a filehandle entry to something
465 that wasn't a symbol table entry.
467 =item Bad symbol for hash
469 (P) An internal request asked to add a hash entry to something that
470 wasn't a symbol table entry.
472 =item Bad symbol for scalar
474 (P) An internal request asked to add a scalar entry to something that
475 wasn't a symbol table entry.
477 =item Bareword found in conditional
479 (W bareword) The compiler found a bareword where it expected a
480 conditional, which often indicates that an || or && was parsed as part
481 of the last argument of the previous construct, for example:
485 It may also indicate a misspelled constant that has been interpreted as
488 use constant TYPO => 1;
489 if (TYOP) { print "foo" }
491 The C<strict> pragma is useful in avoiding such errors.
493 =item Bareword "%s" not allowed while "strict subs" in use
495 (F) With "strict subs" in use, a bareword is only allowed as a
496 subroutine identifier, in curly brackets or to the left of the "=>"
497 symbol. Perhaps you need to predeclare a subroutine?
499 =item Bareword "%s" refers to nonexistent package
501 (W bareword) You used a qualified bareword of the form C<Foo::>, but the
502 compiler saw no other uses of that namespace before that point. Perhaps
503 you need to predeclare a package?
505 =item BEGIN failed--compilation aborted
507 (F) An untrapped exception was raised while executing a BEGIN
508 subroutine. Compilation stops immediately and the interpreter is
511 =item BEGIN not safe after errors--compilation aborted
513 (F) Perl found a C<BEGIN {}> subroutine (or a C<use> directive, which
514 implies a C<BEGIN {}>) after one or more compilation errors had already
515 occurred. Since the intended environment for the C<BEGIN {}> could not
516 be guaranteed (due to the errors), and since subsequent code likely
517 depends on its correct operation, Perl just gave up.
519 =item \%d better written as $%d
521 (W syntax) Outside of patterns, backreferences live on as variables.
522 The use of backslashes is grandfathered on the right-hand side of a
523 substitution, but stylistically it's better to use the variable form
524 because other Perl programmers will expect it, and it works better if
525 there are more than 9 backreferences.
527 =item Binary number > 0b11111111111111111111111111111111 non-portable
529 (W portable) The binary number you specified is larger than 2**32-1
530 (4294967295) and therefore non-portable between systems. See
531 L<perlport> for more on portability concerns.
533 =item bind() on closed socket %s
535 (W closed) You tried to do a bind on a closed socket. Did you forget to
536 check the return value of your socket() call? See L<perlfunc/bind>.
538 =item binmode() on closed filehandle %s
540 (W unopened) You tried binmode() on a filehandle that was never opened.
541 Check your control flow and number of arguments.
543 =item Bit vector size > 32 non-portable
545 (W portable) Using bit vector sizes larger than 32 is non-portable.
547 =item Bizarre copy of %s
549 (P) Perl detected an attempt to copy an internal value that is not
552 =item Bizarre SvTYPE [%d]
554 (P) When starting a new thread or returning values from a thread, Perl
555 encountered an invalid data type.
557 =item Buffer overflow in prime_env_iter: %s
559 (W internal) A warning peculiar to VMS. While Perl was preparing to
560 iterate over %ENV, it encountered a logical name or symbol definition
561 which was too long, so it was truncated to the string shown.
563 =item Callback called exit
565 (F) A subroutine invoked from an external package via call_sv()
566 exited by calling exit.
568 =item %s() called too early to check prototype
570 (W prototype) You've called a function that has a prototype before the
571 parser saw a definition or declaration for it, and Perl could not check
572 that the call conforms to the prototype. You need to either add an
573 early prototype declaration for the subroutine in question, or move the
574 subroutine definition ahead of the call to get proper prototype
575 checking. Alternatively, if you are certain that you're calling the
576 function correctly, you may put an ampersand before the name to avoid
577 the warning. See L<perlsub>.
579 =item Calling POSIX::%s() is deprecated
581 (D deprecated) You called a function whose use is deprecated. See
582 the function's name in L<POSIX> for details.
586 (F) You passed an invalid number (like an infinity or not-a-number) to C<chr>.
588 =item Cannot compress %f in pack
590 (F) You tried compressing an infinity or not-a-number as an unsigned
591 integer with BER, which makes no sense.
593 =item Cannot compress integer in pack
595 (F) An argument to pack("w",...) was too large to compress.
596 The BER compressed integer format can only be used with positive
597 integers, and you attempted to compress a very large number (> 1e308).
598 See L<perlfunc/pack>.
600 =item Cannot compress negative numbers in pack
602 (F) An argument to pack("w",...) was negative. The BER compressed integer
603 format can only be used with positive integers. See L<perlfunc/pack>.
605 =item Cannot convert a reference to %s to typeglob
607 (F) You manipulated Perl's symbol table directly, stored a reference
608 in it, then tried to access that symbol via conventional Perl syntax.
609 The access triggers Perl to autovivify that typeglob, but it there is
610 no legal conversion from that type of reference to a typeglob.
612 =item Cannot copy to %s
614 (P) Perl detected an attempt to copy a value to an internal type that cannot
615 be directly assigned to.
617 =item Cannot find encoding "%s"
619 (S io) You tried to apply an encoding that did not exist to a filehandle,
620 either with open() or binmode().
622 =item Cannot pack %f with '%c'
624 (F) You tried converting an infinity or not-a-number to an integer,
625 which makes no sense.
627 =item Cannot printf %f with '%c'
629 (F) You tried printing an infinity or not-a-number as a character (%c),
630 which makes no sense. Maybe you meant '%s', or just stringifying it?
632 =item Cannot set tied @DB::args
634 (F) C<caller> tried to set C<@DB::args>, but found it tied. Tying C<@DB::args>
635 is not supported. (Before this error was added, it used to crash.)
637 =item Cannot tie unreifiable array
639 (P) You somehow managed to call C<tie> on an array that does not
640 keep a reference count on its arguments and cannot be made to
641 do so. Such arrays are not even supposed to be accessible to
642 Perl code, but are only used internally.
644 =item Can only compress unsigned integers in pack
646 (F) An argument to pack("w",...) was not an integer. The BER compressed
647 integer format can only be used with positive integers, and you attempted
648 to compress something else. See L<perlfunc/pack>.
650 =item Can't bless non-reference value
652 (F) Only hard references may be blessed. This is how Perl "enforces"
653 encapsulation of objects. See L<perlobj>.
655 =item Can't "break" in a loop topicalizer
657 (F) You called C<break>, but you're in a C<foreach> block rather than
658 a C<given> block. You probably meant to use C<next> or C<last>.
660 =item Can't "break" outside a given block
662 (F) You called C<break>, but you're not inside a C<given> block.
664 =item Can't call method "%s" on an undefined value
666 (F) You used the syntax of a method call, but the slot filled by the
667 object reference or package name contains an undefined value. Something
668 like this will reproduce the error:
671 process $BADREF 1,2,3;
672 $BADREF->process(1,2,3);
674 =item Can't call method "%s" on unblessed reference
676 (F) A method call must know in what package it's supposed to run. It
677 ordinarily finds this out from the object reference you supply, but you
678 didn't supply an object reference in this case. A reference isn't an
679 object reference until it has been blessed. See L<perlobj>.
681 =item Can't call method "%s" without a package or object reference
683 (F) You used the syntax of a method call, but the slot filled by the
684 object reference or package name contains an expression that returns a
685 defined value which is neither an object reference nor a package name.
686 Something like this will reproduce the error:
689 process $BADREF 1,2,3;
690 $BADREF->process(1,2,3);
692 =item Can't call mro_isa_changed_in() on anonymous symbol table
694 (P) Perl got confused as to whether a hash was a plain hash or a
695 symbol table hash when trying to update @ISA caches.
697 =item Can't call mro_method_changed_in() on anonymous symbol table
699 (F) An XS module tried to call C<mro_method_changed_in> on a hash that was
700 not attached to the symbol table.
702 =item Can't chdir to %s
704 (F) You called C<perl -x/foo/bar>, but F</foo/bar> is not a directory
705 that you can chdir to, possibly because it doesn't exist.
707 =item Can't check filesystem of script "%s" for nosuid
709 (P) For some reason you can't check the filesystem of the script for
712 =item Can't coerce %s to %s in %s
714 (F) Certain types of SVs, in particular real symbol table entries
715 (typeglobs), can't be forced to stop being what they are. So you can't
725 but then $foo no longer contains a glob.
727 =item Can't "continue" outside a when block
729 (F) You called C<continue>, but you're not inside a C<when>
732 =item Can't create pipe mailbox
734 (P) An error peculiar to VMS. The process is suffering from exhausted
735 quotas or other plumbing problems.
737 =item Can't declare %s in "%s"
739 (F) Only scalar, array, and hash variables may be declared as "my", "our" or
740 "state" variables. They must have ordinary identifiers as names.
742 =item Can't "default" outside a topicalizer
744 (F) You have used a C<default> block that is neither inside a
745 C<foreach> loop nor a C<given> block. (Note that this error is
746 issued on exit from the C<default> block, so you won't get the
747 error if you use an explicit C<continue>.)
749 =item Can't do inplace edit: %s is not a regular file
751 (S inplace) You tried to use the B<-i> switch on a special file, such as
752 a file in /dev, a FIFO or an uneditable directory. The file was ignored.
754 =item Can't do inplace edit on %s: %s
756 (S inplace) The creation of the new file failed for the indicated
759 =item Can't do inplace edit without backup
761 (F) You're on a system such as MS-DOS that gets confused if you try
762 reading from a deleted (but still opened) file. You have to say
763 C<-i.bak>, or some such.
765 =item Can't do inplace edit: %s would not be unique
767 (S inplace) Your filesystem does not support filenames longer than 14
768 characters and Perl was unable to create a unique filename during
769 inplace editing with the B<-i> switch. The file was ignored.
771 =item Can't do %s("%s") on non-UTF-8 locale; resolved to "%s".
773 (W locale) You are 1) running under "C<use locale>"; 2) the current
774 locale is not a UTF-8 one; 3) you tried to do the designated case-change
775 operation on the specified Unicode character; and 4) the result of this
776 operation would mix Unicode and locale rules, which likely conflict.
777 Mixing of different rule types is forbidden, so the operation was not
778 done; instead the result is the indicated value, which is the best
779 available that uses entirely Unicode rules. That turns out to almost
780 always be the original character, unchanged.
782 It is generally a bad idea to mix non-UTF-8 locales and Unicode, and
783 this issue is one of the reasons why. This warning is raised when
784 Unicode rules would normally cause the result of this operation to
785 contain a character that is in the range specified by the locale,
786 0..255, and hence is subject to the locale's rules, not Unicode's.
788 If you are using locale purely for its characteristics related to things
789 like its numeric and time formatting (and not C<LC_CTYPE>), consider
790 using a restricted form of the locale pragma (see L<perllocale/The "use
791 locale" pragma>) like "S<C<use locale ':not_characters'>>".
793 Note that failed case-changing operations done as a result of
794 case-insensitive C</i> regular expression matching will show up in this
795 warning as having the C<fc> operation (as that is what the regular
796 expression engine calls behind the scenes.)
798 =item Can't do waitpid with flags
800 (F) This machine doesn't have either waitpid() or wait4(), so only
801 waitpid() without flags is emulated.
803 =item Can't emulate -%s on #! line
805 (F) The #! line specifies a switch that doesn't make sense at this
806 point. For example, it'd be kind of silly to put a B<-x> on the #!
809 =item Can't %s %s-endian %ss on this platform
811 (F) Your platform's byte-order is neither big-endian nor little-endian,
812 or it has a very strange pointer size. Packing and unpacking big- or
813 little-endian floating point values and pointers may not be possible.
814 See L<perlfunc/pack>.
816 =item Can't exec "%s": %s
818 (W exec) A system(), exec(), or piped open call could not execute the
819 named program for the indicated reason. Typical reasons include: the
820 permissions were wrong on the file, the file wasn't found in
821 C<$ENV{PATH}>, the executable in question was compiled for another
822 architecture, or the #! line in a script points to an interpreter that
823 can't be run for similar reasons. (Or maybe your system doesn't support
828 (F) Perl was trying to execute the indicated program for you because
829 that's what the #! line said. If that's not what you wanted, you may
830 need to mention "perl" on the #! line somewhere.
832 =item Can't execute %s
834 (F) You used the B<-S> switch, but the copies of the script to execute
835 found in the PATH did not have correct permissions.
837 =item Can't find an opnumber for "%s"
839 (F) A string of a form C<CORE::word> was given to prototype(), but there
840 is no builtin with the name C<word>.
842 =item Can't find %s character property "%s"
844 (F) You used C<\p{}> or C<\P{}> but the character property by that name
845 could not be found. Maybe you misspelled the name of the property?
846 See L<perluniprops/Properties accessible through \p{} and \P{}>
847 for a complete list of available official properties.
849 =item Can't find label %s
851 (F) You said to goto a label that isn't mentioned anywhere that it's
852 possible for us to go to. See L<perlfunc/goto>.
854 =item Can't find %s on PATH
856 (F) You used the B<-S> switch, but the script to execute could not be
859 =item Can't find %s on PATH, '.' not in PATH
861 (F) You used the B<-S> switch, but the script to execute could not be
862 found in the PATH, or at least not with the correct permissions. The
863 script exists in the current directory, but PATH prohibits running it.
865 =item Can't find string terminator %s anywhere before EOF
867 (F) Perl strings can stretch over multiple lines. This message means
868 that the closing delimiter was omitted. Because bracketed quotes count
869 nesting levels, the following is missing its final parenthesis:
871 print q(The character '(' starts a side comment.);
873 If you're getting this error from a here-document, you may have
874 included unseen whitespace before or after your closing tag or there
875 may not be a linebreak after it. A good programmer's editor will have
876 a way to help you find these characters (or lack of characters). See
877 L<perlop> for the full details on here-documents.
879 =item Can't find Unicode property definition "%s"
881 (F) You may have tried to use C<\p> which means a Unicode
882 property (for example C<\p{Lu}> matches all uppercase
883 letters). If you did mean to use a Unicode property, see
884 L<perluniprops/Properties accessible through \p{} and \P{}>
885 for a complete list of available properties. If you didn't
886 mean to use a Unicode property, escape the C<\p>, either by
887 C<\\p> (just the C<\p>) or by C<\Q\p> (the rest of the string, or
892 (F) A fatal error occurred while trying to fork while opening a
895 =item Can't fork, trying again in 5 seconds
897 (W pipe) A fork in a piped open failed with EAGAIN and will be retried
900 =item Can't get filespec - stale stat buffer?
902 (S) A warning peculiar to VMS. This arises because of the difference
903 between access checks under VMS and under the Unix model Perl assumes.
904 Under VMS, access checks are done by filename, rather than by bits in
905 the stat buffer, so that ACLs and other protections can be taken into
906 account. Unfortunately, Perl assumes that the stat buffer contains all
907 the necessary information, and passes it, instead of the filespec, to
908 the access-checking routine. It will try to retrieve the filespec using
909 the device name and FID present in the stat buffer, but this works only
910 if you haven't made a subsequent call to the CRTL stat() routine,
911 because the device name is overwritten with each call. If this warning
912 appears, the name lookup failed, and the access-checking routine gave up
913 and returned FALSE, just to be conservative. (Note: The access-checking
914 routine knows about the Perl C<stat> operator and file tests, so you
915 shouldn't ever see this warning in response to a Perl command; it arises
916 only if some internal code takes stat buffers lightly.)
918 =item Can't get pipe mailbox device name
920 (P) An error peculiar to VMS. After creating a mailbox to act as a
921 pipe, Perl can't retrieve its name for later use.
923 =item Can't get SYSGEN parameter value for MAXBUF
925 (P) An error peculiar to VMS. Perl asked $GETSYI how big you want your
926 mailbox buffers to be, and didn't get an answer.
928 =item Can't "goto" into the middle of a foreach loop
930 (F) A "goto" statement was executed to jump into the middle of a foreach
931 loop. You can't get there from here. See L<perlfunc/goto>.
933 =item Can't "goto" out of a pseudo block
935 (F) A "goto" statement was executed to jump out of what might look like
936 a block, except that it isn't a proper block. This usually occurs if
937 you tried to jump out of a sort() block or subroutine, which is a no-no.
938 See L<perlfunc/goto>.
940 =item Can't goto subroutine from an eval-%s
942 (F) The "goto subroutine" call can't be used to jump out of an eval
945 =item Can't goto subroutine from a sort sub (or similar callback)
947 (F) The "goto subroutine" call can't be used to jump out of the
948 comparison sub for a sort(), or from a similar callback (such
949 as the reduce() function in List::Util).
951 =item Can't goto subroutine outside a subroutine
953 (F) The deeply magical "goto subroutine" call can only replace one
954 subroutine call for another. It can't manufacture one out of whole
955 cloth. In general you should be calling it out of only an AUTOLOAD
956 routine anyway. See L<perlfunc/goto>.
958 =item Can't ignore signal CHLD, forcing to default
960 (W signal) Perl has detected that it is being run with the SIGCHLD
961 signal (sometimes known as SIGCLD) disabled. Since disabling this
962 signal will interfere with proper determination of exit status of child
963 processes, Perl has reset the signal to its default value. This
964 situation typically indicates that the parent program under which Perl
965 may be running (e.g. cron) is being very careless.
967 =item Can't kill a non-numeric process ID
969 (F) Process identifiers must be (signed) integers. It is a fatal error to
970 attempt to kill() an undefined, empty-string or otherwise non-numeric
973 =item Can't "last" outside a loop block
975 (F) A "last" statement was executed to break out of the current block,
976 except that there's this itty bitty problem called there isn't a current
977 block. Note that an "if" or "else" block doesn't count as a "loopish"
978 block, as doesn't a block given to sort(), map() or grep(). You can
979 usually double the curlies to get the same effect though, because the
980 inner curlies will be considered a block that loops once. See
983 =item Can't linearize anonymous symbol table
985 (F) Perl tried to calculate the method resolution order (MRO) of a
986 package, but failed because the package stash has no name.
988 =item Can't load '%s' for module %s
990 (F) The module you tried to load failed to load a dynamic extension.
991 This may either mean that you upgraded your version of perl to one
992 that is incompatible with your old dynamic extensions (which is known
993 to happen between major versions of perl), or (more likely) that your
994 dynamic extension was built against an older version of the library
995 that is installed on your system. You may need to rebuild your old
998 =item Can't localize lexical variable %s
1000 (F) You used local on a variable name that was previously declared as a
1001 lexical variable using "my" or "state". This is not allowed. If you
1002 want to localize a package variable of the same name, qualify it with
1005 =item Can't localize through a reference
1007 (F) You said something like C<local $$ref>, which Perl can't currently
1008 handle, because when it goes to restore the old value of whatever $ref
1009 pointed to after the scope of the local() is finished, it can't be sure
1010 that $ref will still be a reference.
1012 =item Can't locate %s
1014 (F) You said to C<do> (or C<require>, or C<use>) a file that couldn't be found.
1015 Perl looks for the file in all the locations mentioned in @INC, unless
1016 the file name included the full path to the file. Perhaps you need
1017 to set the PERL5LIB or PERL5OPT environment variable to say where the
1018 extra library is, or maybe the script needs to add the library name
1019 to @INC. Or maybe you just misspelled the name of the file. See
1020 L<perlfunc/require> and L<lib>.
1022 =item Can't locate auto/%s.al in @INC
1024 (F) A function (or method) was called in a package which allows
1025 autoload, but there is no function to autoload. Most probable causes
1026 are a misprint in a function/method name or a failure to C<AutoSplit>
1027 the file, say, by doing C<make install>.
1029 =item Can't locate loadable object for module %s in @INC
1031 (F) The module you loaded is trying to load an external library, like
1032 for example, F<foo.so> or F<bar.dll>, but the L<DynaLoader> module was
1033 unable to locate this library. See L<DynaLoader>.
1035 =item Can't locate object method "%s" via package "%s"
1037 (F) You called a method correctly, and it correctly indicated a package
1038 functioning as a class, but that package doesn't define that particular
1039 method, nor does any of its base classes. See L<perlobj>.
1041 =item Can't locate object method "%s" via package "%s" (perhaps you forgot
1044 (F) You called a method on a class that did not exist, and the method
1045 could not be found in UNIVERSAL. This often means that a method
1046 requires a package that has not been loaded.
1048 =item Can't locate package %s for @%s::ISA
1050 (W syntax) The @ISA array contained the name of another package that
1051 doesn't seem to exist.
1053 =item Can't locate PerlIO%s
1055 (F) You tried to use in open() a PerlIO layer that does not exist,
1056 e.g. open(FH, ">:nosuchlayer", "somefile").
1058 =item Can't make list assignment to %ENV on this system
1060 (F) List assignment to %ENV is not supported on some systems, notably
1063 =item Can't make loaded symbols global on this platform while loading %s
1065 (S) A module passed the flag 0x01 to DynaLoader::dl_load_file() to request
1066 that symbols from the stated file are made available globally within the
1067 process, but that functionality is not available on this platform. Whilst
1068 the module likely will still work, this may prevent the perl interpreter
1069 from loading other XS-based extensions which need to link directly to
1070 functions defined in the C or XS code in the stated file.
1072 =item Can't modify %s in %s
1074 (F) You aren't allowed to assign to the item indicated, or otherwise try
1075 to change it, such as with an auto-increment.
1077 =item Can't modify nonexistent substring
1079 (P) The internal routine that does assignment to a substr() was handed
1082 =item Can't modify non-lvalue subroutine call
1084 (F) Subroutines meant to be used in lvalue context should be declared as
1085 such. See L<perlsub/"Lvalue subroutines">.
1087 =item Can't modify reference to %s in %s assignment
1089 (F) Only a limited number of constructs can be used as the argument to a
1090 reference constructor on the left-hand side of an assignment, and what
1091 you used was not one of them. See L<perlref/Assigning to References>.
1093 =item Can't modify reference to localized parenthesized array in list
1096 (F) Assigning to C<\local(@array)> or C<\(local @array)> is not supported, as
1097 it is not clear exactly what it should do. If you meant to make @array
1098 refer to some other array, use C<\@array = \@other_array>. If you want to
1099 make the elements of @array aliases of the scalars referenced on the
1100 right-hand side, use C<\(@array) = @scalar_refs>.
1102 =item Can't modify reference to parenthesized hash in list assignment
1104 (F) Assigning to C<\(%hash)> is not supported. If you meant to make %hash
1105 refer to some other hash, use C<\%hash = \%other_hash>. If you want to
1106 make the elements of %hash into aliases of the scalars referenced on the
1107 right-hand side, use a hash slice: C<\@hash{@keys} = @those_scalar_refs>.
1109 =item Can't msgrcv to read-only var
1111 (F) The target of a msgrcv must be modifiable to be used as a receive
1114 =item Can't "next" outside a loop block
1116 (F) A "next" statement was executed to reiterate 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() or
1119 grep(). You can usually double the curlies to get the same effect
1120 though, because the inner curlies will be considered a block that loops
1121 once. See L<perlfunc/next>.
1123 =item Can't open %s: %s
1125 (S inplace) The implicit opening of a file through use of the C<< <> >>
1126 filehandle, either implicitly under the C<-n> or C<-p> command-line
1127 switches, or explicitly, failed for the indicated reason. Usually
1128 this is because you don't have read permission for a file which
1129 you named on the command line.
1131 (F) You tried to call perl with the B<-e> switch, but F</dev/null> (or
1132 your operating system's equivalent) could not be opened.
1134 =item Can't open a reference
1136 (W io) You tried to open a scalar reference for reading or writing,
1137 using the 3-arg open() syntax:
1141 but your version of perl is compiled without perlio, and this form of
1142 open is not supported.
1144 =item Can't open bidirectional pipe
1146 (W pipe) You tried to say C<open(CMD, "|cmd|")>, which is not supported.
1147 You can try any of several modules in the Perl library to do this, such
1148 as IPC::Open2. Alternately, direct the pipe's output to a file using
1149 ">", and then read it in under a different file handle.
1151 =item Can't open error file %s as stderr
1153 (F) An error peculiar to VMS. Perl does its own command line
1154 redirection, and couldn't open the file specified after '2>' or '2>>' on
1155 the command line for writing.
1157 =item Can't open input file %s as stdin
1159 (F) An error peculiar to VMS. Perl does its own command line
1160 redirection, and couldn't open the file specified after '<' on the
1161 command line for reading.
1163 =item Can't open output file %s as stdout
1165 (F) An error peculiar to VMS. Perl does its own command line
1166 redirection, and couldn't open the file specified after '>' or '>>' on
1167 the command line for writing.
1169 =item Can't open output pipe (name: %s)
1171 (P) An error peculiar to VMS. Perl does its own command line
1172 redirection, and couldn't open the pipe into which to send data destined
1175 =item Can't open perl script "%s": %s
1177 (F) The script you specified can't be opened for the indicated reason.
1179 If you're debugging a script that uses #!, and normally relies on the
1180 shell's $PATH search, the -S option causes perl to do that search, so
1181 you don't have to type the path or C<`which $scriptname`>.
1183 =item Can't read CRTL environ
1185 (S) A warning peculiar to VMS. Perl tried to read an element of %ENV
1186 from the CRTL's internal environment array and discovered the array was
1187 missing. You need to figure out where your CRTL misplaced its environ
1188 or define F<PERL_ENV_TABLES> (see L<perlvms>) so that environ is not
1191 =item Can't "redo" outside a loop block
1193 (F) A "redo" statement was executed to restart the current block, but
1194 there isn't a current block. Note that an "if" or "else" block doesn't
1195 count as a "loopish" block, as doesn't a block given to sort(), map()
1196 or grep(). You can usually double the curlies to get the same effect
1197 though, because the inner curlies will be considered a block that
1198 loops once. See L<perlfunc/redo>.
1200 =item Can't remove %s: %s, skipping file
1202 (S inplace) You requested an inplace edit without creating a backup
1203 file. Perl was unable to remove the original file to replace it with
1204 the modified file. The file was left unmodified.
1206 =item Can't rename %s to %s: %s, skipping file
1208 (S inplace) The rename done by the B<-i> switch failed for some reason,
1209 probably because you don't have write permission to the directory.
1211 =item Can't reopen input pipe (name: %s) in binary mode
1213 (P) An error peculiar to VMS. Perl thought stdin was a pipe, and tried
1214 to reopen it to accept binary data. Alas, it failed.
1216 =item Can't represent character for Ox%X on this platform
1218 (F) There is a hard limit to how big a character code point can be due
1219 to the fundamental properties of UTF-8, especially on EBCDIC
1220 platforms. The given code point exceeds that. The only work-around is
1221 to not use such a large code point.
1223 =item Can't reset %ENV on this system
1225 (F) You called C<reset('E')> or similar, which tried to reset
1226 all variables in the current package beginning with "E". In
1227 the main package, that includes %ENV. Resetting %ENV is not
1228 supported on some systems, notably VMS.
1230 =item Can't resolve method "%s" overloading "%s" in package "%s"
1232 (F)(P) Error resolving overloading specified by a method name (as
1233 opposed to a subroutine reference): no such method callable via the
1234 package. If the method name is C<???>, this is an internal error.
1236 =item Can't return %s from lvalue subroutine
1238 (F) Perl detected an attempt to return illegal lvalues (such as
1239 temporary or readonly values) from a subroutine used as an lvalue. This
1242 =item Can't return outside a subroutine
1244 (F) The return statement was executed in mainline code, that is, where
1245 there was no subroutine call to return out of. See L<perlsub>.
1247 =item Can't return %s to lvalue scalar context
1249 (F) You tried to return a complete array or hash from an lvalue
1250 subroutine, but you called the subroutine in a way that made Perl
1251 think you meant to return only one value. You probably meant to
1252 write parentheses around the call to the subroutine, which tell
1253 Perl that the call should be in list context.
1255 =item Can't stat script "%s"
1257 (P) For some reason you can't fstat() the script even though you have it
1258 open already. Bizarre.
1260 =item Can't take log of %g
1262 (F) For ordinary real numbers, you can't take the logarithm of a
1263 negative number or zero. There's a Math::Complex package that comes
1264 standard with Perl, though, if you really want to do that for the
1267 =item Can't take sqrt of %g
1269 (F) For ordinary real numbers, you can't take the square root of a
1270 negative number. There's a Math::Complex package that comes standard
1271 with Perl, though, if you really want to do that.
1273 =item Can't undef active subroutine
1275 (F) You can't undefine a routine that's currently running. You can,
1276 however, redefine it while it's running, and you can even undef the
1277 redefined subroutine while the old routine is running. Go figure.
1279 =item Can't upgrade %s (%d) to %d
1281 (P) The internal sv_upgrade routine adds "members" to an SV, making it
1282 into a more specialized kind of SV. The top several SV types are so
1283 specialized, however, that they cannot be interconverted. This message
1284 indicates that such a conversion was attempted.
1286 =item Can't use '%c' after -mname
1288 (F) You tried to call perl with the B<-m> switch, but you put something
1289 other than "=" after the module name.
1291 =item Can't use a hash as a reference
1293 (F) You tried to use a hash as a reference, as in
1294 C<< %foo->{"bar"} >> or C<< %$ref->{"hello"} >>. Versions of perl
1295 <= 5.22.0 used to allow this syntax, but shouldn't
1296 have. This was deprecated in perl 5.6.1.
1298 =item Can't use an array as a reference
1300 (F) You tried to use an array as a reference, as in
1301 C<< @foo->[23] >> or C<< @$ref->[99] >>. Versions of perl <= 5.22.0
1302 used to allow this syntax, but shouldn't have. This
1303 was deprecated in perl 5.6.1.
1305 =item Can't use anonymous symbol table for method lookup
1307 (F) The internal routine that does method lookup was handed a symbol
1308 table that doesn't have a name. Symbol tables can become anonymous
1309 for example by undefining stashes: C<undef %Some::Package::>.
1311 =item Can't use an undefined value as %s reference
1313 (F) A value used as either a hard reference or a symbolic reference must
1314 be a defined value. This helps to delurk some insidious errors.
1316 =item Can't use bareword ("%s") as %s ref while "strict refs" in use
1318 (F) Only hard references are allowed by "strict refs". Symbolic
1319 references are disallowed. See L<perlref>.
1321 =item Can't use %! because Errno.pm is not available
1323 (F) The first time the C<%!> hash is used, perl automatically loads the
1324 Errno.pm module. The Errno module is expected to tie the %! hash to
1325 provide symbolic names for C<$!> errno values.
1327 =item Can't use both '<' and '>' after type '%c' in %s
1329 (F) A type cannot be forced to have both big-endian and little-endian
1330 byte-order at the same time, so this combination of modifiers is not
1331 allowed. See L<perlfunc/pack>.
1333 =item Can't use 'defined(@array)' (Maybe you should just omit the defined()?)
1335 (F) defined() is not useful on arrays because it
1336 checks for an undefined I<scalar> value. If you want to see if the
1337 array is empty, just use C<if (@array) { # not empty }> for example.
1339 =item Can't use 'defined(%hash)' (Maybe you should just omit the defined()?)
1341 (F) C<defined()> is not usually right on hashes.
1343 Although C<defined %hash> is false on a plain not-yet-used hash, it
1344 becomes true in several non-obvious circumstances, including iterators,
1345 weak references, stash names, even remaining true after C<undef %hash>.
1346 These things make C<defined %hash> fairly useless in practice, so it now
1347 generates a fatal error.
1349 If a check for non-empty is what you wanted then just put it in boolean
1350 context (see L<perldata/Scalar values>):
1356 If you had C<defined %Foo::Bar::QUUX> to check whether such a package
1357 variable exists then that's never really been reliable, and isn't
1358 a good way to enquire about the features of a package, or whether
1361 =item Can't use %s for loop variable
1363 (P) The parser got confused when trying to parse a C<foreach> loop.
1365 =item Can't use global %s in "%s"
1367 (F) You tried to declare a magical variable as a lexical variable. This
1368 is not allowed, because the magic can be tied to only one location
1369 (namely the global variable) and it would be incredibly confusing to
1370 have variables in your program that looked like magical variables but
1373 =item Can't use '%c' in a group with different byte-order in %s
1375 (F) You attempted to force a different byte-order on a type
1376 that is already inside a group with a byte-order modifier.
1377 For example you cannot force little-endianness on a type that
1378 is inside a big-endian group.
1380 =item Can't use "my %s" in sort comparison
1382 (F) The global variables $a and $b are reserved for sort comparisons.
1383 You mentioned $a or $b in the same line as the <=> or cmp operator,
1384 and the variable had earlier been declared as a lexical variable.
1385 Either qualify the sort variable with the package name, or rename the
1388 =item Can't use %s ref as %s ref
1390 (F) You've mixed up your reference types. You have to dereference a
1391 reference of the type needed. You can use the ref() function to
1392 test the type of the reference, if need be.
1394 =item Can't use string ("%s") as %s ref while "strict refs" in use
1396 =item Can't use string ("%s"...) as %s ref while "strict refs" in use
1398 (F) You've told Perl to dereference a string, something which
1399 C<use strict> blocks to prevent it happening accidentally. See
1400 L<perlref/"Symbolic references">. This can be triggered by an C<@> or C<$>
1401 in a double-quoted string immediately before interpolating a variable,
1402 for example in C<"user @$twitter_id">, which says to treat the contents
1403 of C<$twitter_id> as an array reference; use a C<\> to have a literal C<@>
1404 symbol followed by the contents of C<$twitter_id>: C<"user \@$twitter_id">.
1406 =item Can't use subscript on %s
1408 (F) The compiler tried to interpret a bracketed expression as a
1409 subscript. But to the left of the brackets was an expression that
1410 didn't look like a hash or array reference, or anything else subscriptable.
1412 =item Can't use \%c to mean $%c in expression
1414 (W syntax) In an ordinary expression, backslash is a unary operator that
1415 creates a reference to its argument. The use of backslash to indicate a
1416 backreference to a matched substring is valid only as part of a regular
1417 expression pattern. Trying to do this in ordinary Perl code produces a
1418 value that prints out looking like SCALAR(0xdecaf). Use the $1 form
1421 =item Can't weaken a nonreference
1423 (F) You attempted to weaken something that was not a reference. Only
1424 references can be weakened.
1426 =item Can't "when" outside a topicalizer
1428 (F) You have used a when() block that is neither inside a C<foreach>
1429 loop nor a C<given> block. (Note that this error is issued on exit
1430 from the C<when> block, so you won't get the error if the match fails,
1431 or if you use an explicit C<continue>.)
1433 =item Can't x= to read-only value
1435 (F) You tried to repeat a constant value (often the undefined value)
1436 with an assignment operator, which implies modifying the value itself.
1437 Perhaps you need to copy the value to a temporary, and repeat that.
1439 =item Character following "\c" must be printable ASCII
1441 (F) In C<\cI<X>>, I<X> must be a printable (non-control) ASCII character.
1443 Note that ASCII characters that don't map to control characters are
1444 discouraged, and will generate the warning (when enabled)
1445 L</""\c%c" is more clearly written simply as "%s"">.
1447 =item Character in 'C' format wrapped in pack
1453 where $x is either less than 0 or more than 255; the C<"C"> format is
1454 only for encoding native operating system characters (ASCII, EBCDIC,
1455 and so on) and not for Unicode characters, so Perl behaved as if you meant
1459 If you actually want to pack Unicode codepoints, use the C<"U"> format
1462 =item Character in 'c' format wrapped in pack
1468 where $x is either less than -128 or more than 127; the C<"c"> format
1469 is only for encoding native operating system characters (ASCII, EBCDIC,
1470 and so on) and not for Unicode characters, so Perl behaved as if you meant
1472 pack("c", $x & 255);
1474 If you actually want to pack Unicode codepoints, use the C<"U"> format
1477 =item Character in '%c' format wrapped in unpack
1479 (W unpack) You tried something like
1481 unpack("H", "\x{2a1}")
1483 where the format expects to process a byte (a character with a value
1484 below 256), but a higher value was provided instead. Perl uses the
1485 value modulus 256 instead, as if you had provided:
1487 unpack("H", "\x{a1}")
1489 =item Character in 'W' format wrapped in pack
1495 where $x is either less than 0 or more than 255. However, C<U0>-mode
1496 expects all values to fall in the interval [0, 255], so Perl behaved
1499 pack("U0W", $x & 255)
1501 =item Character(s) in '%c' format wrapped in pack
1503 (W pack) You tried something like
1505 pack("u", "\x{1f3}b")
1507 where the format expects to process a sequence of bytes (character with a
1508 value below 256), but some of the characters had a higher value. Perl
1509 uses the character values modulus 256 instead, as if you had provided:
1511 pack("u", "\x{f3}b")
1513 =item Character(s) in '%c' format wrapped in unpack
1515 (W unpack) You tried something like
1517 unpack("s", "\x{1f3}b")
1519 where the format expects to process a sequence of bytes (character with a
1520 value below 256), but some of the characters had a higher value. Perl
1521 uses the character values modulus 256 instead, as if you had provided:
1523 unpack("s", "\x{f3}b")
1525 =item charnames alias definitions may not contain a sequence of multiple spaces
1527 (F) You defined a character name which had multiple space characters
1528 in a row. Change them to single spaces. Usually these names are
1529 defined in the C<:alias> import argument to C<use charnames>, but they
1530 could be defined by a translator installed into C<$^H{charnames}>. See
1531 L<charnames/CUSTOM ALIASES>.
1533 =item charnames alias definitions may not contain trailing white-space
1535 (F) You defined a character name which ended in a space
1536 character. Remove the trailing space(s). Usually these names are
1537 defined in the C<:alias> import argument to C<use charnames>, but they
1538 could be defined by a translator installed into C<$^H{charnames}>.
1539 See L<charnames/CUSTOM ALIASES>.
1541 =item \C is deprecated in regex; marked by <-- HERE in m/%s/
1543 (D deprecated, regexp) The \C character class is deprecated, and will
1544 become a compile-time error in a future release of perl (tentatively
1545 v5.24). This construct allows you to match a single byte of what makes
1546 up a multi-byte single UTF8 character, and breaks encapsulation. It is
1547 currently also very buggy. If you really need to process the individual
1548 bytes, you probably want to convert your string to one where each
1549 underlying byte is stored as a character, with utf8::encode().
1551 =item "\c%c" is more clearly written simply as "%s"
1553 (W syntax) The C<\cI<X>> construct is intended to be a way to specify
1554 non-printable characters. You used it for a printable one, which
1555 is better written as simply itself, perhaps preceded by a backslash
1556 for non-word characters. Doing it the way you did is not portable
1557 between ASCII and EBCDIC platforms.
1559 =item Cloning substitution context is unimplemented
1561 (F) Creating a new thread inside the C<s///> operator is not supported.
1563 =item closedir() attempted on invalid dirhandle %s
1565 (W io) The dirhandle you tried to close is either closed or not really
1566 a dirhandle. Check your control flow.
1568 =item close() on unopened filehandle %s
1570 (W unopened) You tried to close a filehandle that was never opened.
1572 =item Closure prototype called
1574 (F) If a closure has attributes, the subroutine passed to an attribute
1575 handler is the prototype that is cloned when a new closure is created.
1576 This subroutine cannot be called.
1578 =item Code missing after '/'
1580 (F) You had a (sub-)template that ends with a '/'. There must be
1581 another template code following the slash. See L<perlfunc/pack>.
1583 =item Code point 0x%X is not Unicode, may not be portable
1585 (S non_unicode) You had a code point above the Unicode maximum
1588 Perl allows strings to contain a superset of Unicode code points, up
1589 to the limit of what is storable in an unsigned integer on your system,
1590 but these may not be accepted by other languages/systems. At one time,
1591 it was legal in some standards to have code points up to 0x7FFF_FFFF,
1592 but not higher. Code points above 0xFFFF_FFFF require larger than a
1595 =item %s: Command not found
1597 (A) You've accidentally run your script through B<csh> or another shell
1598 instead of Perl. Check the #! line, or manually feed your script into
1599 Perl yourself. The #! line at the top of your file could look like
1603 =item Compilation failed in require
1605 (F) Perl could not compile a file specified in a C<require> statement.
1606 Perl uses this generic message when none of the errors that it
1607 encountered were severe enough to halt compilation immediately.
1609 =item Complex regular subexpression recursion limit (%d) exceeded
1611 (W regexp) The regular expression engine uses recursion in complex
1612 situations where back-tracking is required. Recursion depth is limited
1613 to 32766, or perhaps less in architectures where the stack cannot grow
1614 arbitrarily. ("Simple" and "medium" situations are handled without
1615 recursion and are not subject to a limit.) Try shortening the string
1616 under examination; looping in Perl code (e.g. with C<while>) rather than
1617 in the regular expression engine; or rewriting the regular expression so
1618 that it is simpler or backtracks less. (See L<perlfaq2> for information
1619 on I<Mastering Regular Expressions>.)
1621 =item connect() on closed socket %s
1623 (W closed) You tried to do a connect on a closed socket. Did you forget
1624 to check the return value of your socket() call? See
1625 L<perlfunc/connect>.
1627 =item Constant(%s): Call to &{$^H{%s}} did not return a defined value
1629 (F) The subroutine registered to handle constant overloading
1630 (see L<overload>) or a custom charnames handler (see
1631 L<charnames/CUSTOM TRANSLATORS>) returned an undefined value.
1633 =item Constant(%s): $^H{%s} is not defined
1635 (F) The parser found inconsistencies while attempting to define an
1636 overloaded constant. Perhaps you forgot to load the corresponding
1639 =item Constant is not %s reference
1641 (F) A constant value (perhaps declared using the C<use constant> pragma)
1642 is being dereferenced, but it amounts to the wrong type of reference.
1643 The message indicates the type of reference that was expected. This
1644 usually indicates a syntax error in dereferencing the constant value.
1645 See L<perlsub/"Constant Functions"> and L<constant>.
1647 =item Constants from lexical variables potentially modified elsewhere are
1650 (D deprecated) You wrote something like
1653 $sub = sub () { $var };
1655 but $var is referenced elsewhere and could be modified after the C<sub>
1656 expression is evaluated. Either it is explicitly modified elsewhere
1657 (C<$var = 3>) or it is passed to a subroutine or to an operator like
1658 C<printf> or C<map>, which may or may not modify the variable.
1660 Traditionally, Perl has captured the value of the variable at that
1661 point and turned the subroutine into a constant eligible for inlining.
1662 In those cases where the variable can be modified elsewhere, this
1663 breaks the behavior of closures, in which the subroutine captures
1664 the variable itself, rather than its value, so future changes to the
1665 variable are reflected in the subroutine's return value.
1667 This usage is deprecated, because the behavior is likely to change
1668 in a future version of Perl.
1670 If you intended for the subroutine to be eligible for inlining, then
1671 make sure the variable is not referenced elsewhere, possibly by
1675 $sub = sub () { $var2 };
1677 If you do want this subroutine to be a closure that reflects future
1678 changes to the variable that it closes over, add an explicit C<return>:
1681 $sub = sub () { return $var };
1683 =item Constant subroutine %s redefined
1685 (W redefine)(S) You redefined a subroutine which had previously
1686 been eligible for inlining. See L<perlsub/"Constant Functions">
1687 for commentary and workarounds.
1689 =item Constant subroutine %s undefined
1691 (W misc) You undefined a subroutine which had previously been eligible
1692 for inlining. See L<perlsub/"Constant Functions"> for commentary and
1695 =item Constant(%s) unknown
1697 (F) The parser found inconsistencies either while attempting
1698 to define an overloaded constant, or when trying to find the
1699 character name specified in the C<\N{...}> escape. Perhaps you
1700 forgot to load the corresponding L<overload> pragma?.
1702 =item Copy method did not return a reference
1704 (F) The method which overloads "=" is buggy. See
1705 L<overload/Copy Constructor>.
1707 =item &CORE::%s cannot be called directly
1709 (F) You tried to call a subroutine in the C<CORE::> namespace
1710 with C<&foo> syntax or through a reference. Some subroutines
1711 in this package cannot yet be called that way, but must be
1712 called as barewords. Something like this will work:
1714 BEGIN { *shove = \&CORE::push; }
1715 shove @array, 1,2,3; # pushes on to @array
1717 =item CORE::%s is not a keyword
1719 (F) The CORE:: namespace is reserved for Perl keywords.
1721 =item Corrupted regexp opcode %d > %d
1723 (P) This is either an error in Perl, or, if you're using
1724 one, your L<custom regular expression engine|perlreapi>. If not the
1725 latter, report the problem through the L<perlbug> utility.
1727 =item corrupted regexp pointers
1729 (P) The regular expression engine got confused by what the regular
1730 expression compiler gave it.
1732 =item corrupted regexp program
1734 (P) The regular expression engine got passed a regexp program without a
1737 =item Corrupt malloc ptr 0x%x at 0x%x
1739 (P) The malloc package that comes with Perl had an internal failure.
1741 =item Count after length/code in unpack
1743 (F) You had an unpack template indicating a counted-length string, but
1744 you have also specified an explicit size for the string. See
1748 The following are used in lib/diagnostics.t for testing two =items that
1749 share the same description. Changes here need to be propagated to there
1751 =item Deep recursion on anonymous subroutine
1753 =item Deep recursion on subroutine "%s"
1755 (W recursion) This subroutine has called itself (directly or indirectly)
1756 100 times more than it has returned. This probably indicates an
1757 infinite recursion, unless you're writing strange benchmark programs, in
1758 which case it indicates something else.
1760 This threshold can be changed from 100, by recompiling the F<perl> binary,
1761 setting the C pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value.
1763 =item (?(DEFINE)....) does not allow branches in regex; marked by
1764 S<<-- HERE> in m/%s/
1766 (F) You used something like C<(?(DEFINE)...|..)> which is illegal. The
1767 most likely cause of this error is that you left out a parenthesis inside
1768 of the C<....> part.
1770 The <-- HERE shows whereabouts in the regular expression the problem was
1773 =item %s defines neither package nor VERSION--version check failed
1775 (F) You said something like "use Module 42" but in the Module file
1776 there are neither package declarations nor a C<$VERSION>.
1778 =item delete argument is index/value array slice, use array slice
1780 (F) You used index/value array slice syntax (C<%array[...]>) as
1781 the argument to C<delete>. You probably meant C<@array[...]> with
1782 an @ symbol instead.
1784 =item delete argument is key/value hash slice, use hash slice
1786 (F) You used key/value hash slice syntax (C<%hash{...}>) as the argument to
1787 C<delete>. You probably meant C<@hash{...}> with an @ symbol instead.
1789 =item delete argument is not a HASH or ARRAY element or slice
1791 (F) The argument to C<delete> must be either a hash or array element,
1797 or a hash or array slice, such as:
1799 @foo[$bar, $baz, $xyzzy]
1800 @{$ref->[12]}{"susie", "queue"}
1802 =item Delimiter for here document is too long
1804 (F) In a here document construct like C<<<FOO>, the label C<FOO> is too
1805 long for Perl to handle. You have to be seriously twisted to write code
1806 that triggers this error.
1808 =item Deprecated use of my() in false conditional
1810 (D deprecated) You used a declaration similar to C<my $x if 0>. There
1811 has been a long-standing bug in Perl that causes a lexical variable
1812 not to be cleared at scope exit when its declaration includes a false
1813 conditional. Some people have exploited this bug to achieve a kind of
1814 static variable. Since we intend to fix this bug, we don't want people
1815 relying on this behavior. You can achieve a similar static effect by
1816 declaring the variable in a separate block outside the function, eg
1818 sub f { my $x if 0; return $x++ }
1822 { my $x; sub f { return $x++ } }
1824 Beginning with perl 5.10.0, you can also use C<state> variables to have
1825 lexicals that are initialized only once (see L<feature>):
1827 sub f { state $x; return $x++ }
1829 =item DESTROY created new reference to dead object '%s'
1831 (F) A DESTROY() method created a new reference to the object which is
1832 just being DESTROYed. Perl is confused, and prefers to abort rather
1833 than to create a dangling reference.
1835 =item Did not produce a valid header
1839 =item %s did not return a true value
1841 (F) A required (or used) file must return a true value to indicate that
1842 it compiled correctly and ran its initialization code correctly. It's
1843 traditional to end such a file with a "1;", though any true value would
1844 do. See L<perlfunc/require>.
1846 =item (Did you mean &%s instead?)
1848 (W misc) You probably referred to an imported subroutine &FOO as $FOO or
1851 =item (Did you mean "local" instead of "our"?)
1853 (W misc) Remember that "our" does not localize the declared global
1854 variable. You have declared it again in the same lexical scope, which
1857 =item (Did you mean $ or @ instead of %?)
1859 (W) You probably said %hash{$key} when you meant $hash{$key} or
1860 @hash{@keys}. On the other hand, maybe you just meant %hash and got
1865 (F) You passed die() an empty string (the equivalent of C<die "">) or
1866 you called it with no args and C<$@> was empty.
1868 =item Document contains no data
1872 =item %s does not define %s::VERSION--version check failed
1874 (F) You said something like "use Module 42" but the Module did not
1875 define a C<$VERSION>.
1877 =item '/' does not take a repeat count
1879 (F) You cannot put a repeat count of any kind right after the '/' code.
1880 See L<perlfunc/pack>.
1882 =item Don't know how to get file name
1884 (P) C<PerlIO_getname>, a perl internal I/O function specific to VMS, was
1885 somehow called on another platform. This should not happen.
1887 =item Don't know how to handle magic of type \%o
1889 (P) The internal handling of magical variables has been cursed.
1891 =item do_study: out of memory
1893 (P) This should have been caught by safemalloc() instead.
1895 =item (Do you need to predeclare %s?)
1897 (S syntax) This is an educated guess made in conjunction with the message
1898 "%s found where operator expected". It often means a subroutine or module
1899 name is being referenced that hasn't been declared yet. This may be
1900 because of ordering problems in your file, or because of a missing
1901 "sub", "package", "require", or "use" statement. If you're referencing
1902 something that isn't defined yet, you don't actually have to define the
1903 subroutine or package before the current location. You can use an empty
1904 "sub foo;" or "package FOO;" to enter a "forward" declaration.
1906 =item dump() better written as CORE::dump()
1908 (W misc) You used the obsolescent C<dump()> built-in function, without fully
1909 qualifying it as C<CORE::dump()>. Maybe it's a typo. See L<perlfunc/dump>.
1911 =item dump is not supported
1913 (F) Your machine doesn't support dump/undump.
1915 =item Duplicate free() ignored
1917 (S malloc) An internal routine called free() on something that had
1920 =item Duplicate modifier '%c' after '%c' in %s
1922 (W unpack) You have applied the same modifier more than once after a
1923 type in a pack template. See L<perlfunc/pack>.
1925 =item each on reference is experimental
1927 (S experimental::autoderef) C<each> with a scalar argument is experimental
1928 and may change or be removed in a future Perl version. If you want to
1929 take the risk of using this feature, simply disable this warning:
1931 no warnings "experimental::autoderef";
1933 =item elseif should be elsif
1935 (S syntax) There is no keyword "elseif" in Perl because Larry thinks
1936 it's ugly. Your code will be interpreted as an attempt to call a method
1937 named "elseif" for the class returned by the following block. This is
1938 unlikely to be what you want.
1940 =item Empty \%c{} in regex; marked by S<<-- HERE> in m/%s/
1942 (F) C<\p> and C<\P> are used to introduce a named Unicode property, as
1943 described in L<perlunicode> and L<perlre>. You used C<\p> or C<\P> in
1944 a regular expression without specifying the property name.
1946 =item entering effective %s failed
1948 (F) While under the C<use filetest> pragma, switching the real and
1949 effective uids or gids failed.
1951 =item %ENV is aliased to %s
1953 (F) You're running under taint mode, and the C<%ENV> variable has been
1954 aliased to another hash, so it doesn't reflect anymore the state of the
1955 program's environment. This is potentially insecure.
1957 =item Error converting file specification %s
1959 (F) An error peculiar to VMS. Because Perl may have to deal with file
1960 specifications in either VMS or Unix syntax, it converts them to a
1961 single form when it must operate on them directly. Either you've passed
1962 an invalid file specification to Perl, or you've found a case the
1963 conversion routines don't handle. Drat.
1965 =item Eval-group in insecure regular expression
1967 (F) Perl detected tainted data when trying to compile a regular
1968 expression that contains the C<(?{ ... })> zero-width assertion, which
1969 is unsafe. See L<perlre/(?{ code })>, and L<perlsec>.
1971 =item Eval-group not allowed at runtime, use re 'eval' in regex m/%s/
1973 (F) Perl tried to compile a regular expression containing the
1974 C<(?{ ... })> zero-width assertion at run time, as it would when the
1975 pattern contains interpolated values. Since that is a security risk,
1976 it is not allowed. If you insist, you may still do this by using the
1977 C<re 'eval'> pragma or by explicitly building the pattern from an
1978 interpolated string at run time and using that in an eval(). See
1979 L<perlre/(?{ code })>.
1981 =item Eval-group not allowed, use re 'eval' in regex m/%s/
1983 (F) A regular expression contained the C<(?{ ... })> zero-width
1984 assertion, but that construct is only allowed when the C<use re 'eval'>
1985 pragma is in effect. See L<perlre/(?{ code })>.
1987 =item EVAL without pos change exceeded limit in regex; marked by
1988 S<<-- HERE> in m/%s/
1990 (F) You used a pattern that nested too many EVAL calls without consuming
1991 any text. Restructure the pattern so that text is consumed.
1993 The <-- HERE shows whereabouts in the regular expression the problem was
1996 =item Excessively long <> operator
1998 (F) The contents of a <> operator may not exceed the maximum size of a
1999 Perl identifier. If you're just trying to glob a long list of
2000 filenames, try using the glob() operator, or put the filenames into a
2001 variable and glob that.
2003 =item exec? I'm not *that* kind of operating system
2005 (F) The C<exec> function is not implemented on some systems, e.g., Symbian
2006 OS. See L<perlport>.
2008 =item Execution of %s aborted due to compilation errors.
2010 (F) The final summary message when a Perl compilation fails.
2012 =item exists argument is not a HASH or ARRAY element or a subroutine
2014 (F) The argument to C<exists> must be a hash or array element or a
2015 subroutine with an ampersand, such as:
2021 =item exists argument is not a subroutine name
2023 (F) The argument to C<exists> for C<exists &sub> must be a subroutine name,
2024 and not a subroutine call. C<exists &sub()> will generate this error.
2026 =item Exiting eval via %s
2028 (W exiting) You are exiting an eval by unconventional means, such as a
2029 goto, or a loop control statement.
2031 =item Exiting format via %s
2033 (W exiting) You are exiting a format by unconventional means, such as a
2034 goto, or a loop control statement.
2036 =item Exiting pseudo-block via %s
2038 (W exiting) You are exiting a rather special block construct (like a
2039 sort block or subroutine) by unconventional means, such as a goto, or a
2040 loop control statement. See L<perlfunc/sort>.
2042 =item Exiting subroutine via %s
2044 (W exiting) You are exiting a subroutine by unconventional means, such
2045 as a goto, or a loop control statement.
2047 =item Exiting substitution via %s
2049 (W exiting) You are exiting a substitution by unconventional means, such
2050 as a return, a goto, or a loop control statement.
2052 =item Expecting close bracket in regex; marked by S<<-- HERE> in m/%s/
2054 (F) You wrote something like
2058 to denote a capturing group of the form
2059 L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>,
2060 but omitted the C<")">.
2062 =item Expecting '(?flags:(?[...' in regex; marked by S<<-- HERE> in m/%s/
2064 (F) The C<(?[...])> extended character class regular expression construct
2065 only allows character classes (including character class escapes like
2066 C<\d>), operators, and parentheses. The one exception is C<(?flags:...)>
2067 containing at least one flag and exactly one C<(?[...])> construct.
2068 This allows a regular expression containing just C<(?[...])> to be
2069 interpolated. If you see this error message, then you probably
2070 have some other C<(?...)> construct inside your character class. See
2071 L<perlrecharclass/Extended Bracketed Character Classes>.
2073 =item Experimental aliasing via reference not enabled
2075 (F) To do aliasing via references, you must first enable the feature:
2077 no warnings "experimental::refaliasing";
2078 use feature "refaliasing";
2081 =item Experimental subroutine signatures not enabled
2083 (F) To use subroutine signatures, you must first enable them:
2085 no warnings "experimental::signatures";
2086 use feature "signatures";
2087 sub foo ($left, $right) { ... }
2089 =item Experimental "%s" subs not enabled
2091 (F) To use lexical subs, you must first enable them:
2093 no warnings 'experimental::lexical_subs';
2094 use feature 'lexical_subs';
2097 =item Explicit blessing to '' (assuming package main)
2099 (W misc) You are blessing a reference to a zero length string. This has
2100 the effect of blessing the reference into the package main. This is
2101 usually not what you want. Consider providing a default target package,
2102 e.g. bless($ref, $p || 'MyPackage');
2104 =item %s: Expression syntax
2106 (A) You've accidentally run your script through B<csh> instead of Perl.
2107 Check the #! line, or manually feed your script into Perl yourself.
2109 =item %s failed--call queue aborted
2111 (F) An untrapped exception was raised while executing a UNITCHECK,
2112 CHECK, INIT, or END subroutine. Processing of the remainder of the
2113 queue of such routines has been prematurely ended.
2115 =item False [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
2117 (W regexp)(F) A character class range must start and end at a literal
2118 character, not another character class like C<\d> or C<[:alpha:]>. The "-"
2119 in your false range is interpreted as a literal "-". In a C<(?[...])>
2120 construct, this is an error, rather than a warning. Consider quoting
2121 the "-", "\-". The S<<-- HERE> shows whereabouts in the regular expression
2122 the problem was discovered. See L<perlre>.
2124 =item Fatal VMS error (status=%d) at %s, line %d
2126 (P) An error peculiar to VMS. Something untoward happened in a VMS
2127 system service or RTL routine; Perl's exit status should provide more
2128 details. The filename in "at %s" and the line number in "line %d" tell
2129 you which section of the Perl source code is distressed.
2131 =item fcntl is not implemented
2133 (F) Your machine apparently doesn't implement fcntl(). What is this, a
2134 PDP-11 or something?
2136 =item FETCHSIZE returned a negative value
2138 (F) A tied array claimed to have a negative number of elements, which
2141 =item Field too wide in 'u' format in pack
2143 (W pack) Each line in an uuencoded string starts with a length indicator
2144 which can't encode values above 63. So there is no point in asking for
2145 a line length bigger than that. Perl will behave as if you specified
2146 C<u63> as the format.
2148 =item Filehandle %s opened only for input
2150 (W io) You tried to write on a read-only filehandle. If you intended
2151 it to be a read-write filehandle, you needed to open it with "+<" or
2152 "+>" or "+>>" instead of with "<" or nothing. If you intended only to
2153 write the file, use ">" or ">>". See L<perlfunc/open>.
2155 =item Filehandle %s opened only for output
2157 (W io) You tried to read from a filehandle opened only for writing, If
2158 you intended it to be a read/write filehandle, you needed to open it
2159 with "+<" or "+>" or "+>>" instead of with ">". If you intended only to
2160 read from the file, use "<". See L<perlfunc/open>. Another possibility
2161 is that you attempted to open filedescriptor 0 (also known as STDIN) for
2162 output (maybe you closed STDIN earlier?).
2164 =item Filehandle %s reopened as %s only for input
2166 (W io) You opened for reading a filehandle that got the same filehandle id
2167 as STDOUT or STDERR. This occurred because you closed STDOUT or STDERR
2170 =item Filehandle STDIN reopened as %s only for output
2172 (W io) You opened for writing a filehandle that got the same filehandle id
2173 as STDIN. This occurred because you closed STDIN previously.
2175 =item Final $ should be \$ or $name
2177 (F) You must now decide whether the final $ in a string was meant to be
2178 a literal dollar sign, or was meant to introduce a variable name that
2179 happens to be missing. So you have to put either the backslash or the
2182 =item flock() on closed filehandle %s
2184 (W closed) The filehandle you're attempting to flock() got itself closed
2185 some time before now. Check your control flow. flock() operates on
2186 filehandles. Are you attempting to call flock() on a dirhandle by the
2189 =item Format not terminated
2191 (F) A format must be terminated by a line with a solitary dot. Perl got
2192 to the end of your file without finding such a line.
2194 =item Format %s redefined
2196 (W redefine) You redefined a format. To suppress this warning, say
2199 no warnings 'redefine';
2200 eval "format NAME =...";
2203 =item Found = in conditional, should be ==
2213 (or something like that).
2215 =item %s found where operator expected
2217 (S syntax) The Perl lexer knows whether to expect a term or an operator.
2218 If it sees what it knows to be a term when it was expecting to see an
2219 operator, it gives you this warning. Usually it indicates that an
2220 operator or delimiter was omitted, such as a semicolon.
2222 =item gdbm store returned %d, errno %d, key "%s"
2224 (S) A warning from the GDBM_File extension that a store failed.
2226 =item gethostent not implemented
2228 (F) Your C library apparently doesn't implement gethostent(), probably
2229 because if it did, it'd feel morally obligated to return every hostname
2232 =item get%sname() on closed socket %s
2234 (W closed) You tried to get a socket or peer socket name on a closed
2235 socket. Did you forget to check the return value of your socket() call?
2237 =item getpwnam returned invalid UIC %#o for user "%s"
2239 (S) A warning peculiar to VMS. The call to C<sys$getuai> underlying the
2240 C<getpwnam> operator returned an invalid UIC.
2242 =item getsockopt() on closed socket %s
2244 (W closed) You tried to get a socket option on a closed socket. Did you
2245 forget to check the return value of your socket() call? See
2246 L<perlfunc/getsockopt>.
2248 =item given is experimental
2250 (S experimental::smartmatch) C<given> depends on smartmatch, which
2251 is experimental, so its behavior may change or even be removed
2252 in any future release of perl. See the explanation under
2253 L<perlsyn/Experimental Details on given and when>.
2255 =item Global symbol "%s" requires explicit package name (did you forget to
2258 (F) You've said "use strict" or "use strict vars", which indicates
2259 that all variables must either be lexically scoped (using "my" or "state"),
2260 declared beforehand using "our", or explicitly qualified to say
2261 which package the global variable is in (using "::").
2263 =item glob failed (%s)
2265 (S glob) Something went wrong with the external program(s) used
2266 for C<glob> and C<< <*.c> >>. Usually, this means that you supplied a C<glob>
2267 pattern that caused the external program to fail and exit with a
2268 nonzero status. If the message indicates that the abnormal exit
2269 resulted in a coredump, this may also mean that your csh (C shell)
2270 is broken. If so, you should change all of the csh-related variables
2271 in config.sh: If you have tcsh, make the variables refer to it as
2272 if it were csh (e.g. C<full_csh='/usr/bin/tcsh'>); otherwise, make them
2273 all empty (except that C<d_csh> should be C<'undef'>) so that Perl will
2274 think csh is missing. In either case, after editing config.sh, run
2275 C<./Configure -S> and rebuild Perl.
2277 =item Glob not terminated
2279 (F) The lexer saw a left angle bracket in a place where it was expecting
2280 a term, so it's looking for the corresponding right angle bracket, and
2281 not finding it. Chances are you left some needed parentheses out
2282 earlier in the line, and you really meant a "less than".
2284 =item gmtime(%f) failed
2286 (W overflow) You called C<gmtime> with a number that it could not handle:
2287 too large, too small, or NaN. The returned value is C<undef>.
2289 =item gmtime(%f) too large
2291 (W overflow) You called C<gmtime> with a number that was larger than
2292 it can reliably handle and C<gmtime> probably returned the wrong
2293 date. This warning is also triggered with NaN (the special
2294 not-a-number value).
2296 =item gmtime(%f) too small
2298 (W overflow) You called C<gmtime> with a number that was smaller than
2299 it can reliably handle and C<gmtime> probably returned the wrong date.
2301 =item Got an error from DosAllocMem
2303 (P) An error peculiar to OS/2. Most probably you're using an obsolete
2304 version of Perl, and this should not happen anyway.
2306 =item goto must have label
2308 (F) Unlike with "next" or "last", you're not allowed to goto an
2309 unspecified destination. See L<perlfunc/goto>.
2311 =item Goto undefined subroutine%s
2313 (F) You tried to call a subroutine with C<goto &sub> syntax, but
2314 the indicated subroutine hasn't been defined, or if it was, it
2315 has since been undefined.
2317 =item Group name must start with a non-digit word character in regex; marked by
2318 S<<-- HERE> in m/%s/
2320 (F) Group names must follow the rules for perl identifiers, meaning
2321 they must start with a non-digit word character. A common cause of
2322 this error is using (?&0) instead of (?0). See L<perlre>.
2324 =item ()-group starts with a count
2326 (F) A ()-group started with a count. A count is supposed to follow
2327 something: a template character or a ()-group. See L<perlfunc/pack>.
2329 =item %s had compilation errors.
2331 (F) The final summary message when a C<perl -c> fails.
2333 =item Had to create %s unexpectedly
2335 (S internal) A routine asked for a symbol from a symbol table that ought
2336 to have existed already, but for some reason it didn't, and had to be
2337 created on an emergency basis to prevent a core dump.
2339 =item %s has too many errors
2341 (F) The parser has given up trying to parse the program after 10 errors.
2342 Further error messages would likely be uninformative.
2344 =item Having more than one /%c regexp modifier is deprecated
2346 (D deprecated, regexp) You used the indicated regular expression pattern
2347 modifier at least twice in a string of modifiers. It is deprecated to
2348 do this with this particular modifier, to allow future extensions to the
2351 =item Hexadecimal float: exponent overflow
2353 (W overflow) The hexadecimal floating point has a larger exponent
2354 than the floating point supports.
2356 =item Hexadecimal float: exponent underflow
2358 (W overflow) The hexadecimal floating point has a smaller exponent
2359 than the floating point supports.
2361 =item Hexadecimal float: internal error
2363 (F) Something went horribly bad in hexadecimal float handling.
2365 =item Hexadecimal float: mantissa overflow
2367 (W overflow) The hexadecimal floating point literal had more bits in
2368 the mantissa (the part between the 0x and the exponent, also known as
2369 the fraction or the significand) than the floating point supports.
2371 =item Hexadecimal float: precision loss
2373 (W overflow) The hexadecimal floating point had internally more
2374 digits than could be output. This can be caused by unsupported
2375 long double formats, or by 64-bit integers not being available
2376 (needed to retrieve the digits under some configurations).
2378 =item Hexadecimal float: unsupported long double format
2380 (F) You have configured Perl to use long doubles but
2381 the internals of the long double format are unknown;
2382 therefore the hexadecimal float output is impossible.
2384 =item Hexadecimal number > 0xffffffff non-portable
2386 (W portable) The hexadecimal number you specified is larger than 2**32-1
2387 (4294967295) and therefore non-portable between systems. See
2388 L<perlport> for more on portability concerns.
2390 =item Identifier too long
2392 (F) Perl limits identifiers (names for variables, functions, etc.) to
2393 about 250 characters for simple names, and somewhat more for compound
2394 names (like C<$A::B>). You've exceeded Perl's limits. Future versions
2395 of Perl are likely to eliminate these arbitrary limitations.
2397 =item Ignoring zero length \N{} in character class in regex; marked by
2398 S<<-- HERE> in m/%s/
2400 (W regexp) Named Unicode character escapes (C<\N{...}>) may return a
2401 zero-length sequence. When such an escape is used in a character
2402 class its behavior is not well defined. Check that the correct
2403 escape has been used, and the correct charname handler is in scope.
2405 =item Illegal binary digit %s
2407 (F) You used a digit other than 0 or 1 in a binary number.
2409 =item Illegal binary digit %s ignored
2411 (W digit) You may have tried to use a digit other than 0 or 1 in a
2412 binary number. Interpretation of the binary number stopped before the
2415 =item Illegal character after '_' in prototype for %s : %s
2417 (W illegalproto) An illegal character was found in a prototype
2418 declaration. The '_' in a prototype must be followed by a ';',
2419 indicating the rest of the parameters are optional, or one of '@'
2420 or '%', since those two will accept 0 or more final parameters.
2422 =item Illegal character \%o (carriage return)
2424 (F) Perl normally treats carriage returns in the program text as it
2425 would any other whitespace, which means you should never see this error
2426 when Perl was built using standard options. For some reason, your
2427 version of Perl appears to have been built without this support. Talk
2428 to your Perl administrator.
2430 =item Illegal character in prototype for %s : %s
2432 (W illegalproto) An illegal character was found in a prototype declaration.
2433 Legal characters in prototypes are $, @, %, *, ;, [, ], &, \, and +.
2434 Perhaps you were trying to write a subroutine signature but didn't enable
2435 that feature first (C<use feature 'signatures'>), so your signature was
2436 instead interpreted as a bad prototype.
2438 =item Illegal declaration of anonymous subroutine
2440 (F) When using the C<sub> keyword to construct an anonymous subroutine,
2441 you must always specify a block of code. See L<perlsub>.
2443 =item Illegal declaration of subroutine %s
2445 (F) A subroutine was not declared correctly. See L<perlsub>.
2447 =item Illegal division by zero
2449 (F) You tried to divide a number by 0. Either something was wrong in
2450 your logic, or you need to put a conditional in to guard against
2453 =item Illegal hexadecimal digit %s ignored
2455 (W digit) You may have tried to use a character other than 0 - 9 or
2456 A - F, a - f in a hexadecimal number. Interpretation of the hexadecimal
2457 number stopped before the illegal character.
2459 =item Illegal modulus zero
2461 (F) You tried to divide a number by 0 to get the remainder. Most
2462 numbers don't take to this kindly.
2464 =item Illegal number of bits in vec
2466 (F) The number of bits in vec() (the third argument) must be a power of
2467 two from 1 to 32 (or 64, if your platform supports that).
2469 =item Illegal octal digit %s
2471 (F) You used an 8 or 9 in an octal number.
2473 =item Illegal octal digit %s ignored
2475 (W digit) You may have tried to use an 8 or 9 in an octal number.
2476 Interpretation of the octal number stopped before the 8 or 9.
2478 =item Illegal pattern in regex; marked by S<<-- HERE> in m/%s/
2480 (F) You wrote something like
2484 The C<"+"> is valid only when followed by digits, indicating a
2485 capturing group. See
2486 L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>.
2488 =item Illegal suidscript
2490 (F) The script run under suidperl was somehow illegal.
2492 =item Illegal switch in PERL5OPT: -%c
2494 (X) The PERL5OPT environment variable may only be used to set the
2495 following switches: B<-[CDIMUdmtw]>.
2497 =item Ill-formed CRTL environ value "%s"
2499 (W internal) A warning peculiar to VMS. Perl tried to read the CRTL's
2500 internal environ array, and encountered an element without the C<=>
2501 delimiter used to separate keys from values. The element is ignored.
2503 =item Ill-formed message in prime_env_iter: |%s|
2505 (W internal) A warning peculiar to VMS. Perl tried to read a logical
2506 name or CLI symbol definition when preparing to iterate over %ENV, and
2507 didn't see the expected delimiter between key and value, so the line was
2510 =item (in cleanup) %s
2512 (W misc) This prefix usually indicates that a DESTROY() method raised
2513 the indicated exception. Since destructors are usually called by the
2514 system at arbitrary points during execution, and often a vast number of
2515 times, the warning is issued only once for any number of failures that
2516 would otherwise result in the same message being repeated.
2518 Failure of user callbacks dispatched using the C<G_KEEPERR> flag could
2519 also result in this warning. See L<perlcall/G_KEEPERR>.
2521 =item Incomplete expression within '(?[ ])' in regex; marked by S<<-- HERE>
2524 (F) There was a syntax error within the C<(?[ ])>. This can happen if the
2525 expression inside the construct was completely empty, or if there are
2526 too many or few operands for the number of operators. Perl is not smart
2527 enough to give you a more precise indication as to what is wrong.
2529 =item Inconsistent hierarchy during C3 merge of class '%s': merging failed on
2532 (F) The method resolution order (MRO) of the given class is not
2533 C3-consistent, and you have enabled the C3 MRO for this class. See the C3
2534 documentation in L<mro> for more information.
2536 =item In EBCDIC the v-string components cannot exceed 2147483647
2538 (F) An error peculiar to EBCDIC. Internally, v-strings are stored as
2539 Unicode code points, and encoded in EBCDIC as UTF-EBCDIC. The UTF-EBCDIC
2540 encoding is limited to code points no larger than 2147483647 (0x7FFFFFFF).
2542 =item Infinite recursion in regex
2544 (F) You used a pattern that references itself without consuming any input
2545 text. You should check the pattern to ensure that recursive patterns
2546 either consume text or fail.
2548 =item Initialization of state variables in list context currently forbidden
2550 (F) Currently the implementation of "state" only permits the
2551 initialization of scalar variables in scalar context. Re-write
2552 C<state ($a) = 42> as C<state $a = 42> to change from list to scalar
2553 context. Constructions such as C<state (@a) = foo()> will be
2554 supported in a future perl release.
2556 =item %%s[%s] in scalar context better written as $%s[%s]
2558 (W syntax) In scalar context, you've used an array index/value slice
2559 (indicated by %) to select a single element of an array. Generally
2560 it's better to ask for a scalar value (indicated by $). The difference
2561 is that C<$foo[&bar]> always behaves like a scalar, both in the value it
2562 returns and when evaluating its argument, while C<%foo[&bar]> provides
2563 a list context to its subscript, which can do weird things if you're
2564 expecting only one subscript. When called in list context, it also
2565 returns the index (what C<&bar> returns) in addition to the value.
2567 =item %%s{%s} in scalar context better written as $%s{%s}
2569 (W syntax) In scalar context, you've used a hash key/value slice
2570 (indicated by %) to select a single element of a hash. Generally it's
2571 better to ask for a scalar value (indicated by $). The difference
2572 is that C<$foo{&bar}> always behaves like a scalar, both in the value
2573 it returns and when evaluating its argument, while C<@foo{&bar}> and
2574 provides a list context to its subscript, which can do weird things
2575 if you're expecting only one subscript. When called in list context,
2576 it also returns the key in addition to the value.
2578 =item Insecure dependency in %s
2580 (F) You tried to do something that the tainting mechanism didn't like.
2581 The tainting mechanism is turned on when you're running setuid or
2582 setgid, or when you specify B<-T> to turn it on explicitly. The
2583 tainting mechanism labels all data that's derived directly or indirectly
2584 from the user, who is considered to be unworthy of your trust. If any
2585 such data is used in a "dangerous" operation, you get this error. See
2586 L<perlsec> for more information.
2588 =item Insecure directory in %s
2590 (F) You can't use system(), exec(), or a piped open in a setuid or
2591 setgid script if C<$ENV{PATH}> contains a directory that is writable by
2592 the world. Also, the PATH must not contain any relative directory.
2595 =item Insecure $ENV{%s} while running %s
2597 (F) You can't use system(), exec(), or a piped open in a setuid or
2598 setgid script if any of C<$ENV{PATH}>, C<$ENV{IFS}>, C<$ENV{CDPATH}>,
2599 C<$ENV{ENV}>, C<$ENV{BASH_ENV}> or C<$ENV{TERM}> are derived from data
2600 supplied (or potentially supplied) by the user. The script must set
2601 the path to a known value, using trustworthy data. See L<perlsec>.
2603 =item Insecure user-defined property %s
2605 (F) Perl detected tainted data when trying to compile a regular
2606 expression that contains a call to a user-defined character property
2607 function, i.e. C<\p{IsFoo}> or C<\p{InFoo}>.
2608 See L<perlunicode/User-Defined Character Properties> and L<perlsec>.
2610 =item Integer overflow in format string for %s
2612 (F) The indexes and widths specified in the format string of C<printf()>
2613 or C<sprintf()> are too large. The numbers must not overflow the size of
2614 integers for your architecture.
2616 =item Integer overflow in %s number
2618 (S overflow) The hexadecimal, octal or binary number you have specified
2619 either as a literal or as an argument to hex() or oct() is too big for
2620 your architecture, and has been converted to a floating point number.
2621 On a 32-bit architecture the largest hexadecimal, octal or binary number
2622 representable without overflow is 0xFFFFFFFF, 037777777777, or
2623 0b11111111111111111111111111111111 respectively. Note that Perl
2624 transparently promotes all numbers to a floating point representation
2625 internally--subject to loss of precision errors in subsequent
2628 =item Integer overflow in srand
2630 (S overflow) The number you have passed to srand is too big to fit
2631 in your architecture's integer representation. The number has been
2632 replaced with the largest integer supported (0xFFFFFFFF on 32-bit
2633 architectures). This means you may be getting less randomness than
2634 you expect, because different random seeds above the maximum will
2635 return the same sequence of random numbers.
2637 =item Integer overflow in version
2639 =item Integer overflow in version %d
2641 (W overflow) Some portion of a version initialization is too large for
2642 the size of integers for your architecture. This is not a warning
2643 because there is no rational reason for a version to try and use an
2644 element larger than typically 2**32. This is usually caused by trying
2645 to use some odd mathematical operation as a version, like 100/9.
2647 =item Internal disaster in regex; marked by S<<-- HERE> in m/%s/
2649 (P) Something went badly wrong in the regular expression parser.
2650 The S<<-- HERE> shows whereabouts in the regular expression the problem was
2653 =item Internal inconsistency in tracking vforks
2655 (S) A warning peculiar to VMS. Perl keeps track of the number of times
2656 you've called C<fork> and C<exec>, to determine whether the current call
2657 to C<exec> should affect the current script or a subprocess (see
2658 L<perlvms/"exec LIST">). Somehow, this count has become scrambled, so
2659 Perl is making a guess and treating this C<exec> as a request to
2660 terminate the Perl script and execute the specified command.
2662 =item internal %<num>p might conflict with future printf extensions
2664 (S internal) Perl's internal routine that handles C<printf> and C<sprintf>
2665 formatting follows a slightly different set of rules when called from
2666 C or XS code. Specifically, formats consisting of digits followed
2667 by "p" (e.g., "%7p") are reserved for future use. If you see this
2668 message, then an XS module tried to call that routine with one such
2671 =item Internal urp in regex; marked by S<<-- HERE> in m/%s/
2673 (P) Something went badly awry in the regular expression parser. The
2674 S<<-- HERE> shows whereabouts in the regular expression the problem was
2677 =item %s (...) interpreted as function
2679 (W syntax) You've run afoul of the rule that says that any list operator
2680 followed by parentheses turns into a function, with all the list
2681 operators arguments found inside the parentheses. See
2682 L<perlop/Terms and List Operators (Leftward)>.
2684 =item In '(?...)', the '(' and '?' must be adjacent in regex;
2685 marked by S<<-- HERE> in m/%s/
2687 (F) The two-character sequence C<"(?"> in this context in a regular
2688 expression pattern should be an indivisible token, with nothing
2689 intervening between the C<"("> and the C<"?">, but you separated them
2692 =item Invalid %s attribute: %s
2694 (F) The indicated attribute for a subroutine or variable was not recognized
2695 by Perl or by a user-supplied handler. See L<attributes>.
2697 =item Invalid %s attributes: %s
2699 (F) The indicated attributes for a subroutine or variable were not
2700 recognized by Perl or by a user-supplied handler. See L<attributes>.
2702 =item Invalid character in charnames alias definition; marked by
2705 (F) You tried to create a custom alias for a character name, with
2706 the C<:alias> option to C<use charnames> and the specified character in
2707 the indicated name isn't valid. See L<charnames/CUSTOM ALIASES>.
2709 =item Invalid \0 character in %s for %s: %s\0%s
2711 (W syscalls) Embedded \0 characters in pathnames or other system call
2712 arguments produce a warning as of 5.20. The parts after the \0 were
2713 formerly ignored by system calls.
2715 =item Invalid character in \N{...}; marked by S<<-- HERE> in \N{%s}
2717 (F) Only certain characters are valid for character names. The
2718 indicated one isn't. See L<charnames/CUSTOM ALIASES>.
2720 =item Invalid conversion in %s: "%s"
2722 (W printf) Perl does not understand the given format conversion. See
2723 L<perlfunc/sprintf>.
2725 =item Invalid escape in the specified encoding in regex; marked by
2726 S<<-- HERE> in m/%s/
2728 (W regexp)(F) The numeric escape (for example C<\xHH>) of value < 256
2729 didn't correspond to a single character through the conversion
2730 from the encoding specified by the encoding pragma.
2731 The escape was replaced with REPLACEMENT CHARACTER (U+FFFD)
2732 instead, except within S<C<(?[ ])>>, where it is a fatal error.
2733 The S<<-- HERE> shows whereabouts in the regular expression the
2734 escape was discovered.
2736 =item Invalid hexadecimal number in \N{U+...}
2738 =item Invalid hexadecimal number in \N{U+...} in regex; marked by
2739 S<<-- HERE> in m/%s/
2741 (F) The character constant represented by C<...> is not a valid hexadecimal
2742 number. Either it is empty, or you tried to use a character other than
2743 0 - 9 or A - F, a - f in a hexadecimal number.
2745 =item Invalid module name %s with -%c option: contains single ':'
2747 (F) The module argument to perl's B<-m> and B<-M> command-line options
2748 cannot contain single colons in the module name, but only in the
2749 arguments after "=". In other words, B<-MFoo::Bar=:baz> is ok, but
2750 B<-MFoo:Bar=baz> is not.
2752 =item Invalid mro name: '%s'
2754 (F) You tried to C<mro::set_mro("classname", "foo")> or C<use mro 'foo'>,
2755 where C<foo> is not a valid method resolution order (MRO). Currently,
2756 the only valid ones supported are C<dfs> and C<c3>, unless you have loaded
2757 a module that is a MRO plugin. See L<mro> and L<perlmroapi>.
2759 =item Invalid negative number (%s) in chr
2761 (W utf8) You passed a negative number to C<chr>. Negative numbers are
2762 not valid character numbers, so it returns the Unicode replacement
2765 =item invalid option -D%c, use -D'' to see choices
2767 (S debugging) Perl was called with invalid debugger flags. Call perl
2768 with the B<-D> option with no flags to see the list of acceptable values.
2769 See also L<perlrun/-Dletters>.
2771 =item Invalid [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
2773 (F) The range specified in a character class had a minimum character
2774 greater than the maximum character. One possibility is that you forgot the
2775 C<{}> from your ending C<\x{}> - C<\x> without the curly braces can go only
2776 up to C<ff>. The S<<-- HERE> shows whereabouts in the regular expression the
2777 problem was discovered. See L<perlre>.
2779 =item Invalid range "%s" in transliteration operator
2781 (F) The range specified in the tr/// or y/// operator had a minimum
2782 character greater than the maximum character. See L<perlop>.
2784 =item Invalid separator character %s in attribute list
2786 (F) Something other than a colon or whitespace was seen between the
2787 elements of an attribute list. If the previous attribute had a
2788 parenthesised parameter list, perhaps that list was terminated too soon.
2791 =item Invalid separator character %s in PerlIO layer specification %s
2793 (W layer) When pushing layers onto the Perl I/O system, something other
2794 than a colon or whitespace was seen between the elements of a layer list.
2795 If the previous attribute had a parenthesised parameter list, perhaps that
2796 list was terminated too soon.
2798 =item Invalid strict version format (%s)
2800 (F) A version number did not meet the "strict" criteria for versions.
2801 A "strict" version number is a positive decimal number (integer or
2802 decimal-fraction) without exponentiation or else a dotted-decimal
2803 v-string with a leading 'v' character and at least three components.
2804 The parenthesized text indicates which criteria were not met.
2805 See the L<version> module for more details on allowed version formats.
2807 =item Invalid type '%s' in %s
2809 (F) The given character is not a valid pack or unpack type.
2810 See L<perlfunc/pack>.
2812 (W) The given character is not a valid pack or unpack type but used to be
2815 =item Invalid version format (%s)
2817 (F) A version number did not meet the "lax" criteria for versions.
2818 A "lax" version number is a positive decimal number (integer or
2819 decimal-fraction) without exponentiation or else a dotted-decimal
2820 v-string. If the v-string has fewer than three components, it
2821 must have a leading 'v' character. Otherwise, the leading 'v' is
2822 optional. Both decimal and dotted-decimal versions may have a
2823 trailing "alpha" component separated by an underscore character
2824 after a fractional or dotted-decimal component. The parenthesized
2825 text indicates which criteria were not met. See the L<version> module
2826 for more details on allowed version formats.
2828 =item Invalid version object
2830 (F) The internal structure of the version object was invalid.
2831 Perhaps the internals were modified directly in some way or
2832 an arbitrary reference was blessed into the "version" class.
2834 =item In '(*VERB...)', the '(' and '*' must be adjacent in regex;
2835 marked by S<<-- HERE> in m/%s/
2837 (F) The two-character sequence C<"(*"> in
2838 this context in a regular expression pattern should be an
2839 indivisible token, with nothing intervening between the C<"(">
2840 and the C<"*">, but you separated them.
2842 =item ioctl is not implemented
2844 (F) Your machine apparently doesn't implement ioctl(), which is pretty
2845 strange for a machine that supports C.
2847 =item ioctl() on unopened %s
2849 (W unopened) You tried ioctl() on a filehandle that was never opened.
2850 Check your control flow and number of arguments.
2852 =item IO layers (like '%s') unavailable
2854 (F) Your Perl has not been configured to have PerlIO, and therefore
2855 you cannot use IO layers. To have PerlIO, Perl must be configured
2858 =item IO::Socket::atmark not implemented on this architecture
2860 (F) Your machine doesn't implement the sockatmark() functionality,
2861 neither as a system call nor an ioctl call (SIOCATMARK).
2863 =item $* is no longer supported
2865 (D deprecated, syntax) The special variable C<$*>, deprecated in older
2866 perls, has been removed as of 5.10.0 and is no longer supported. In
2867 previous versions of perl the use of C<$*> enabled or disabled multi-line
2868 matching within a string.
2870 Instead of using C<$*> you should use the C</m> (and maybe C</s>) regexp
2871 modifiers. You can enable C</m> for a lexical scope (even a whole file)
2872 with C<use re '/m'>. (In older versions: when C<$*> was set to a true value
2873 then all regular expressions behaved as if they were written using C</m>.)
2875 =item $# is no longer supported
2877 (D deprecated, syntax) The special variable C<$#>, deprecated in older
2878 perls, has been removed as of 5.10.0 and is no longer supported. You
2879 should use the printf/sprintf functions instead.
2881 =item '%s' is not a code reference
2883 (W overload) The second (fourth, sixth, ...) argument of
2884 overload::constant needs to be a code reference. Either
2885 an anonymous subroutine, or a reference to a subroutine.
2887 =item '%s' is not an overloadable type
2889 (W overload) You tried to overload a constant type the overload package is
2892 =item -i used with no filenames on the command line, reading from STDIN
2894 (S inplace) The C<-i> option was passed on the command line, indicating
2895 that the script is intended to edit files in place, but no files were
2896 given. This is usually a mistake, since editing STDIN in place doesn't
2897 make sense, and can be confusing because it can make perl look like
2898 it is hanging when it is really just trying to read from STDIN. You
2899 should either pass a filename to edit, or remove C<-i> from the command
2900 line. See L<perlrun> for more details.
2902 =item Junk on end of regexp in regex m/%s/
2904 (P) The regular expression parser is confused.
2906 =item keys on reference is experimental
2908 (S experimental::autoderef) C<keys> with a scalar argument is experimental
2909 and may change or be removed in a future Perl version. If you want to
2910 take the risk of using this feature, simply disable this warning:
2912 no warnings "experimental::autoderef";
2914 =item Label not found for "last %s"
2916 (F) You named a loop to break out of, but you're not currently in a loop
2917 of that name, not even if you count where you were called from. See
2920 =item Label not found for "next %s"
2922 (F) You named a loop to continue, but you're not currently in a loop of
2923 that name, not even if you count where you were called from. See
2926 =item Label not found for "redo %s"
2928 (F) You named a loop to restart, but you're not currently in a loop of
2929 that name, not even if you count where you were called from. See
2932 =item leaving effective %s failed
2934 (F) While under the C<use filetest> pragma, switching the real and
2935 effective uids or gids failed.
2937 =item length/code after end of string in unpack
2939 (F) While unpacking, the string buffer was already used up when an unpack
2940 length/code combination tried to obtain more data. This results in
2941 an undefined value for the length. See L<perlfunc/pack>.
2943 =item length() used on %s (did you mean "scalar(%s)"?)
2945 (W syntax) You used length() on either an array or a hash when you
2946 probably wanted a count of the items.
2948 Array size can be obtained by doing:
2952 The number of items in a hash can be obtained by doing:
2956 =item Lexing code attempted to stuff non-Latin-1 character into Latin-1 input
2958 (F) An extension is attempting to insert text into the current parse
2959 (using L<lex_stuff_pvn|perlapi/lex_stuff_pvn> or similar), but tried to insert a character that
2960 couldn't be part of the current input. This is an inherent pitfall
2961 of the stuffing mechanism, and one of the reasons to avoid it. Where
2962 it is necessary to stuff, stuffing only plain ASCII is recommended.
2964 =item Lexing code internal error (%s)
2966 (F) Lexing code supplied by an extension violated the lexer's API in a
2969 =item listen() on closed socket %s
2971 (W closed) You tried to do a listen on a closed socket. Did you forget
2972 to check the return value of your socket() call? See
2975 =item List form of piped open not implemented
2977 (F) On some platforms, notably Windows, the three-or-more-arguments
2978 form of C<open> does not support pipes, such as C<open($pipe, '|-', @args)>.
2979 Use the two-argument C<open($pipe, '|prog arg1 arg2...')> form instead.
2981 =item %s: loadable library and perl binaries are mismatched (got handshake key %p, needed %p)
2983 (P) A dynamic loading library C<.so> or C<.dll> was being loaded into the
2984 process that was built against a different build of perl than the
2985 said library was compiled against. Reinstalling the XS module will
2986 likely fix this error.
2988 =item Locale '%s' may not work well.%s
2990 (W locale) You are using the named locale, which is a non-UTF-8 one, and
2991 which Perl has determined is not fully compatible with Perl. The second
2992 C<%s> gives a reason.
2994 By far the most common reason is that the locale has characters in it
2995 that are represented by more than one byte. The only such locales that
2996 Perl can handle are the UTF-8 locales. Most likely the specified locale
2997 is a non-UTF-8 one for an East Asian language such as Chinese or
2998 Japanese. If the locale is a superset of ASCII, the ASCII portion of it
3001 Some essentially obsolete locales that aren't supersets of ASCII, mainly
3002 those in ISO 646 or other 7-bit locales, such as ASMO 449, can also have
3003 problems, depending on what portions of the ASCII character set get
3004 changed by the locale and are also used by the program.
3005 The warning message lists the determinable conflicting characters.
3007 Note that not all incompatibilities are found.
3009 If this happens to you, there's not much you can do except switch to use a
3010 different locale or use L<Encode> to translate from the locale into
3011 UTF-8; if that's impracticable, you have been warned that some things
3014 This message is output once each time a bad locale is switched into
3015 within the scope of C<S<use locale>>, or on the first possibly-affected
3016 operation if the C<S<use locale>> inherits a bad one. It is not raised
3017 for any operations from the L<POSIX> module.
3019 =item localtime(%f) failed
3021 (W overflow) You called C<localtime> with a number that it could not handle:
3022 too large, too small, or NaN. The returned value is C<undef>.
3024 =item localtime(%f) too large
3026 (W overflow) You called C<localtime> with a number that was larger
3027 than it can reliably handle and C<localtime> probably returned the
3028 wrong date. This warning is also triggered with NaN (the special
3029 not-a-number value).
3031 =item localtime(%f) too small
3033 (W overflow) You called C<localtime> with a number that was smaller
3034 than it can reliably handle and C<localtime> probably returned the
3037 =item Lookbehind longer than %d not implemented in regex m/%s/
3039 (F) There is currently a limit on the length of string which lookbehind can
3040 handle. This restriction may be eased in a future release.
3042 =item Lost precision when %s %f by 1
3044 (W imprecision) The value you attempted to increment or decrement by one
3045 is too large for the underlying floating point representation to store
3046 accurately, hence the target of C<++> or C<--> is unchanged. Perl issues this
3047 warning because it has already switched from integers to floating point
3048 when values are too large for integers, and now even floating point is
3049 insufficient. You may wish to switch to using L<Math::BigInt> explicitly.
3051 =item lstat() on filehandle%s
3053 (W io) You tried to do an lstat on a filehandle. What did you mean
3054 by that? lstat() makes sense only on filenames. (Perl did a fstat()
3055 instead on the filehandle.)
3057 =item lvalue attribute %s already-defined subroutine
3059 (W misc) Although L<attributes.pm|attributes> allows this, turning the lvalue
3060 attribute on or off on a Perl subroutine that is already defined
3061 does not always work properly. It may or may not do what you
3062 want, depending on what code is inside the subroutine, with exact
3063 details subject to change between Perl versions. Only do this
3064 if you really know what you are doing.
3066 =item lvalue attribute ignored after the subroutine has been defined
3068 (W misc) Using the C<:lvalue> declarative syntax to make a Perl
3069 subroutine an lvalue subroutine after it has been defined is
3070 not permitted. To make the subroutine an lvalue subroutine,
3071 add the lvalue attribute to the definition, or put the C<sub
3072 foo :lvalue;> declaration before the definition.
3074 See also L<attributes.pm|attributes>.
3076 =item Magical list constants are not supported
3078 (F) You assigned a magical array to a stash element, and then tried
3079 to use the subroutine from the same slot. You are asking Perl to do
3080 something it cannot do, details subject to change between Perl versions.
3082 =item Malformed integer in [] in pack
3084 (F) Between the brackets enclosing a numeric repeat count only digits
3085 are permitted. See L<perlfunc/pack>.
3087 =item Malformed integer in [] in unpack
3089 (F) Between the brackets enclosing a numeric repeat count only digits
3090 are permitted. See L<perlfunc/pack>.
3092 =item Malformed PERLLIB_PREFIX
3094 (F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form
3101 with nonempty prefix1 and prefix2. If C<prefix1> is indeed a prefix of
3102 a builtin library search path, prefix2 is substituted. The error may
3103 appear if components are not found, or are too long. See
3104 "PERLLIB_PREFIX" in L<perlos2>.
3106 =item Malformed prototype for %s: %s
3108 (F) You tried to use a function with a malformed prototype. The
3109 syntax of function prototypes is given a brief compile-time check for
3110 obvious errors like invalid characters. A more rigorous check is run
3111 when the function is called.
3112 Perhaps the function's author was trying to write a subroutine signature
3113 but didn't enable that feature first (C<use feature 'signatures'>),
3114 so the signature was instead interpreted as a bad prototype.
3116 =item Malformed UTF-8 character (%s)
3118 (S utf8)(F) Perl detected a string that didn't comply with UTF-8
3119 encoding rules, even though it had the UTF8 flag on.
3121 One possible cause is that you set the UTF8 flag yourself for data that
3122 you thought to be in UTF-8 but it wasn't (it was for example legacy
3123 8-bit data). To guard against this, you can use Encode::decode_utf8.
3125 If you use the C<:encoding(UTF-8)> PerlIO layer for input, invalid byte
3126 sequences are handled gracefully, but if you use C<:utf8>, the flag is
3127 set without validating the data, possibly resulting in this error
3130 See also L<Encode/"Handling Malformed Data">.
3132 =item Malformed UTF-8 character immediately after '%s'
3134 (F) You said C<use utf8>, but the program file doesn't comply with UTF-8
3135 encoding rules. The message prints out the properly encoded characters
3136 just before the first bad one. If C<utf8> warnings are enabled, a
3137 warning is generated that gives more details about the type of
3140 =item Malformed UTF-8 returned by \N{%s} immediately after '%s'
3142 (F) The charnames handler returned malformed UTF-8.
3144 =item Malformed UTF-8 string in '%c' format in unpack
3146 (F) You tried to unpack something that didn't comply with UTF-8 encoding
3147 rules and perl was unable to guess how to make more progress.
3149 =item Malformed UTF-8 string in pack
3151 (F) You tried to pack something that didn't comply with UTF-8 encoding
3152 rules and perl was unable to guess how to make more progress.
3154 =item Malformed UTF-8 string in unpack
3156 (F) You tried to unpack something that didn't comply with UTF-8 encoding
3157 rules and perl was unable to guess how to make more progress.
3159 =item Malformed UTF-16 surrogate
3161 (F) Perl thought it was reading UTF-16 encoded character data but while
3162 doing it Perl met a malformed Unicode surrogate.
3164 =item Mandatory parameter follows optional parameter
3166 (F) In a subroutine signature, you wrote something like "$a = undef,
3167 $b", making an earlier parameter optional and a later one mandatory.
3168 Parameters are filled from left to right, so it's impossible for the
3169 caller to omit an earlier one and pass a later one. If you want to act
3170 as if the parameters are filled from right to left, declare the rightmost
3171 optional and then shuffle the parameters around in the subroutine's body.
3173 =item Matched non-Unicode code point 0x%X against Unicode property; may
3176 (S non_unicode) Perl allows strings to contain a superset of
3177 Unicode code points; each code point may be as large as what is storable
3178 in an unsigned integer on your system, but these may not be accepted by
3179 other languages/systems. This message occurs when you matched a string
3180 containing such a code point against a regular expression pattern, and
3181 the code point was matched against a Unicode property, C<\p{...}> or
3182 C<\P{...}>. Unicode properties are only defined on Unicode code points,
3183 so the result of this match is undefined by Unicode, but Perl (starting
3184 in v5.20) treats non-Unicode code points as if they were typical
3185 unassigned Unicode ones, and matched this one accordingly. Whether a
3186 given property matches these code points or not is specified in
3187 L<perluniprops/Properties accessible through \p{} and \P{}>.
3189 This message is suppressed (unless it has been made fatal) if it is
3190 immaterial to the results of the match if the code point is Unicode or
3191 not. For example, the property C<\p{ASCII_Hex_Digit}> only can match
3192 the 22 characters C<[0-9A-Fa-f]>, so obviously all other code points,
3193 Unicode or not, won't match it. (And C<\P{ASCII_Hex_Digit}> will match
3194 every code point except these 22.)
3196 Getting this message indicates that the outcome of the match arguably
3197 should have been the opposite of what actually happened. If you think
3198 that is the case, you may wish to make the C<non_unicode> warnings
3199 category fatal; if you agree with Perl's decision, you may wish to turn
3202 See L<perlunicode/Beyond Unicode code points> for more information.
3204 =item %s matches null string many times in regex; marked by S<<-- HERE> in
3207 (W regexp) The pattern you've specified would be an infinite loop if the
3208 regular expression engine didn't specifically check for that. The S<<-- HERE>
3209 shows whereabouts in the regular expression the problem was discovered.
3212 =item Maximal count of pending signals (%u) exceeded
3214 (F) Perl aborted due to too high a number of signals pending. This
3215 usually indicates that your operating system tried to deliver signals
3216 too fast (with a very high priority), starving the perl process from
3217 resources it would need to reach a point where it can process signals
3218 safely. (See L<perlipc/"Deferred Signals (Safe Signals)">.)
3220 =item "%s" may clash with future reserved word
3222 (W) This warning may be due to running a perl5 script through a perl4
3223 interpreter, especially if the word that is being warned about is
3226 =item '%' may not be used in pack
3228 (F) You can't pack a string by supplying a checksum, because the
3229 checksumming process loses information, and you can't go the other way.
3230 See L<perlfunc/unpack>.
3232 =item Method for operation %s not found in package %s during blessing
3234 (F) An attempt was made to specify an entry in an overloading table that
3235 doesn't resolve to a valid subroutine. See L<overload>.
3237 =item Method %s not permitted
3241 =item Might be a runaway multi-line %s string starting on line %d
3243 (S) An advisory indicating that the previous error may have been caused
3244 by a missing delimiter on a string or pattern, because it eventually
3245 ended earlier on the current line.
3247 =item Misplaced _ in number
3249 (W syntax) An underscore (underbar) in a numeric constant did not
3250 separate two digits.
3252 =item Missing argument in %s
3254 (W missing) You called a function with fewer arguments than other
3255 arguments you supplied indicated would be needed.
3257 Currently only emitted when a printf-type format required more
3258 arguments than were supplied, but might be used in the future for
3259 other cases where we can statically determine that arguments to
3260 functions are missing, e.g. for the L<perlfunc/pack> function.
3262 =item Missing argument to -%c
3264 (F) The argument to the indicated command line switch must follow
3265 immediately after the switch, without intervening spaces.
3267 =item Missing braces on \N{}
3269 =item Missing braces on \N{} in regex; marked by S<<-- HERE> in m/%s/
3271 (F) Wrong syntax of character name literal C<\N{charname}> within
3272 double-quotish context. This can also happen when there is a space
3273 (or comment) between the C<\N> and the C<{> in a regex with the C</x> modifier.
3274 This modifier does not change the requirement that the brace immediately
3277 =item Missing braces on \o{}
3279 (F) A C<\o> must be followed immediately by a C<{> in double-quotish context.
3281 =item Missing comma after first argument to %s function
3283 (F) While certain functions allow you to specify a filehandle or an
3284 "indirect object" before the argument list, this ain't one of them.
3286 =item Missing command in piped open
3288 (W pipe) You used the C<open(FH, "| command")> or
3289 C<open(FH, "command |")> construction, but the command was missing or
3292 =item Missing control char name in \c
3294 (F) A double-quoted string ended with "\c", without the required control
3297 =item Missing ']' in prototype for %s : %s
3299 (W illegalproto) A grouping was started with C<[> but never closed with C<]>.
3301 =item Missing name in "%s sub"
3303 (F) The syntax for lexically scoped subroutines requires that
3304 they have a name with which they can be found.
3306 =item Missing $ on loop variable
3308 (F) Apparently you've been programming in B<csh> too much. Variables
3309 are always mentioned with the $ in Perl, unlike in the shells, where it
3310 can vary from one line to the next.
3312 =item (Missing operator before %s?)
3314 (S syntax) This is an educated guess made in conjunction with the message
3315 "%s found where operator expected". Often the missing operator is a comma.
3317 =item Missing or undefined argument to require
3319 (F) You tried to call require with no argument or with an undefined
3320 value as an argument. Require expects either a package name or a
3321 file-specification as an argument. See L<perlfunc/require>.
3323 =item Missing right brace on \%c{} in regex; marked by S<<-- HERE> in m/%s/
3325 (F) Missing right brace in C<\x{...}>, C<\p{...}>, C<\P{...}>, or C<\N{...}>.
3327 =item Missing right brace on \N{}
3329 =item Missing right brace on \N{} or unescaped left brace after \N
3331 (F) C<\N> has two meanings.
3333 The traditional one has it followed by a name enclosed in braces,
3334 meaning the character (or sequence of characters) given by that
3335 name. Thus C<\N{ASTERISK}> is another way of writing C<*>, valid in both
3336 double-quoted strings and regular expression patterns. In patterns,
3337 it doesn't have the meaning an unescaped C<*> does.
3339 Starting in Perl 5.12.0, C<\N> also can have an additional meaning (only)
3340 in patterns, namely to match a non-newline character. (This is short
3341 for C<[^\n]>, and like C<.> but is not affected by the C</s> regex modifier.)
3343 This can lead to some ambiguities. When C<\N> is not followed immediately
3344 by a left brace, Perl assumes the C<[^\n]> meaning. Also, if the braces
3345 form a valid quantifier such as C<\N{3}> or C<\N{5,}>, Perl assumes that this
3346 means to match the given quantity of non-newlines (in these examples,
3347 3; and 5 or more, respectively). In all other case, where there is a
3348 C<\N{> and a matching C<}>, Perl assumes that a character name is desired.
3350 However, if there is no matching C<}>, Perl doesn't know if it was
3351 mistakenly omitted, or if C<[^\n]{> was desired, and raises this error.
3352 If you meant the former, add the right brace; if you meant the latter,
3353 escape the brace with a backslash, like so: C<\N\{>
3355 =item Missing right curly or square bracket
3357 (F) The lexer counted more opening curly or square brackets than closing
3358 ones. As a general rule, you'll find it's missing near the place you
3361 =item (Missing semicolon on previous line?)
3363 (S syntax) This is an educated guess made in conjunction with the message
3364 "%s found where operator expected". Don't automatically put a semicolon on
3365 the previous line just because you saw this message.
3367 =item Modification of a read-only value attempted
3369 (F) You tried, directly or indirectly, to change the value of a
3370 constant. You didn't, of course, try "2 = 1", because the compiler
3371 catches that. But an easy way to do the same thing is:
3373 sub mod { $_[0] = 1 }
3376 Another way is to assign to a substr() that's off the end of the string.
3378 Yet another way is to assign to a C<foreach> loop I<VAR> when I<VAR>
3379 is aliased to a constant in the look I<LIST>:
3382 foreach my $n ($x, 2) {
3383 $n *= 2; # modifies the $x, but fails on attempt to
3386 =item Modification of non-creatable array value attempted, %s
3388 (F) You tried to make an array value spring into existence, and the
3389 subscript was probably negative, even counting from end of the array
3392 =item Modification of non-creatable hash value attempted, %s
3394 (P) You tried to make a hash value spring into existence, and it
3395 couldn't be created for some peculiar reason.
3397 =item Module name must be constant
3399 (F) Only a bare module name is allowed as the first argument to a "use".
3401 =item Module name required with -%c option
3403 (F) The C<-M> or C<-m> options say that Perl should load some module, but
3404 you omitted the name of the module. Consult L<perlrun> for full details
3405 about C<-M> and C<-m>.
3407 =item More than one argument to '%s' open
3409 (F) The C<open> function has been asked to open multiple files. This
3410 can happen if you are trying to open a pipe to a command that takes a
3411 list of arguments, but have forgotten to specify a piped open mode.
3412 See L<perlfunc/open> for details.
3414 =item mprotect for COW string %p %u failed with %d
3416 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_COW (see
3417 L<perlguts/"Copy on Write">), but a shared string buffer
3418 could not be made read-only.
3420 =item mprotect for %p %u failed with %d
3422 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_OPS (see L<perlhacktips>),
3423 but an op tree could not be made read-only.
3425 =item mprotect RW for COW string %p %u failed with %d
3427 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_COW (see
3428 L<perlguts/"Copy on Write">), but a read-only shared string
3429 buffer could not be made mutable.
3431 =item mprotect RW for %p %u failed with %d
3433 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_OPS (see
3434 L<perlhacktips>), but a read-only op tree could not be made
3435 mutable before freeing the ops.
3437 =item msg%s not implemented
3439 (F) You don't have System V message IPC on your system.
3441 =item Multidimensional syntax %s not supported
3443 (W syntax) Multidimensional arrays aren't written like C<$foo[1,2,3]>.
3444 They're written like C<$foo[1][2][3]>, as in C.
3446 =item '/' must follow a numeric type in unpack
3448 (F) You had an unpack template that contained a '/', but this did not
3449 follow some unpack specification producing a numeric value.
3450 See L<perlfunc/pack>.
3452 =item "my sub" not yet implemented
3454 (F) Lexically scoped subroutines are not yet implemented. Don't try
3457 =item "my" subroutine %s can't be in a package
3459 (F) Lexically scoped subroutines aren't in a package, so it doesn't make
3460 sense to try to declare one with a package qualifier on the front.
3462 =item "my %s" used in sort comparison
3464 (W syntax) The package variables $a and $b are used for sort comparisons.
3465 You used $a or $b in as an operand to the C<< <=> >> or C<cmp> operator inside a
3466 sort comparison block, and the variable had earlier been declared as a
3467 lexical variable. Either qualify the sort variable with the package
3468 name, or rename the lexical variable.
3470 =item "my" variable %s can't be in a package
3472 (F) Lexically scoped variables aren't in a package, so it doesn't make
3473 sense to try to declare one with a package qualifier on the front. Use
3474 local() if you want to localize a package variable.
3476 =item Name "%s::%s" used only once: possible typo
3478 (W once) Typographical errors often show up as unique variable
3479 names. If you had a good reason for having a unique name, then
3480 just mention it again somehow to suppress the message. The C<our>
3481 declaration is also provided for this purpose.
3483 NOTE: This warning detects package symbols that have been used
3484 only once. This means lexical variables will never trigger this
3485 warning. It also means that all of the package variables $c, @c,
3486 %c, as well as *c, &c, sub c{}, c(), and c (the filehandle or
3487 format) are considered the same; if a program uses $c only once
3488 but also uses any of the others it will not trigger this warning.
3489 Symbols beginning with an underscore and symbols using special
3490 identifiers (q.v. L<perldata>) are exempt from this warning.
3492 =item Need exactly 3 octal digits in regex; marked by S<<-- HERE> in m/%s/
3494 (F) Within S<C<(?[ ])>>, all constants interpreted as octal need to be
3495 exactly 3 digits long. This helps catch some ambiguities. If your
3496 constant is too short, add leading zeros, like
3498 (?[ [ \078 ] ]) # Syntax error!
3499 (?[ [ \0078 ] ]) # Works
3500 (?[ [ \007 8 ] ]) # Clearer
3502 The maximum number this construct can express is C<\777>. If you
3503 need a larger one, you need to use L<\o{}|perlrebackslash/Octal escapes> instead. If you meant
3504 two separate things, you need to separate them:
3506 (?[ [ \7776 ] ]) # Syntax error!
3507 (?[ [ \o{7776} ] ]) # One meaning
3508 (?[ [ \777 6 ] ]) # Another meaning
3509 (?[ [ \777 \006 ] ]) # Still another
3511 =item Negative '/' count in unpack
3513 (F) The length count obtained from a length/code unpack operation was
3514 negative. See L<perlfunc/pack>.
3516 =item Negative length
3518 (F) You tried to do a read/write/send/recv operation with a buffer
3519 length that is less than 0. This is difficult to imagine.
3521 =item Negative offset to vec in lvalue context
3523 (F) When C<vec> is called in an lvalue context, the second argument must be
3524 greater than or equal to zero.
3526 =item Negative repeat count does nothing
3528 (W numeric) You tried to execute the
3529 L<C<x>|perlop/Multiplicative Operators> repetition operator fewer than 0
3530 times, which doesn't make sense.
3532 =item Nested quantifiers in regex; marked by S<<-- HERE> in m/%s/
3534 (F) You can't quantify a quantifier without intervening parentheses.
3535 So things like ** or +* or ?* are illegal. The S<<-- HERE> shows
3536 whereabouts in the regular expression the problem was discovered.
3538 Note that the minimal matching quantifiers, C<*?>, C<+?>, and
3539 C<??> appear to be nested quantifiers, but aren't. See L<perlre>.
3541 =item %s never introduced
3543 (S internal) The symbol in question was declared but somehow went out of
3544 scope before it could possibly have been used.
3546 =item next::method/next::can/maybe::next::method cannot find enclosing method
3548 (F) C<next::method> needs to be called within the context of a
3549 real method in a real package, and it could not find such a context.
3552 =item \N in a character class must be a named character: \N{...} in regex;
3553 marked by S<<-- HERE> in m/%s/
3555 (F) The new (as of Perl 5.12) meaning of C<\N> as C<[^\n]> is not valid in a
3556 bracketed character class, for the same reason that C<.> in a character
3557 class loses its specialness: it matches almost everything, which is
3558 probably not what you want.
3560 =item \N{} in inverted character class or as a range end-point is restricted to one character in regex; marked
3561 by S<<-- HERE> in m/%s/
3563 (F) Named Unicode character escapes (C<\N{...}>) may return a
3564 multi-character sequence. Even though a character class is
3565 supposed to match just one character of input, perl will match the
3566 whole thing correctly, except when the class is inverted (C<[^...]>),
3567 or the escape is the beginning or final end point of a range. The
3568 mathematically logical behavior for what matches when inverting
3569 is very different from what people expect, so we have decided to
3570 forbid it. Similarly unclear is what should be generated when the
3571 C<\N{...}> is used as one of the end points of the range, such as in
3573 [\x{41}-\N{ARABIC SEQUENCE YEH WITH HAMZA ABOVE WITH AE}]
3575 What is meant here is unclear, as the C<\N{...}> escape is a sequence
3576 of code points, so this is made an error.
3578 =item \N{NAME} must be resolved by the lexer in regex; marked by
3579 S<<-- HERE> in m/%s/
3581 (F) When compiling a regex pattern, an unresolved named character or
3582 sequence was encountered. This can happen in any of several ways that
3583 bypass the lexer, such as using single-quotish context, or an extra
3584 backslash in double-quotish:
3586 $re = '\N{SPACE}'; # Wrong!
3587 $re = "\\N{SPACE}"; # Wrong!
3590 Instead, use double-quotes with a single backslash:
3592 $re = "\N{SPACE}"; # ok
3595 The lexer can be bypassed as well by creating the pattern from smaller
3599 /${re}{SPACE}/; # Wrong!
3601 It's not a good idea to split a construct in the middle like this, and
3602 it doesn't work here. Instead use the solution above.
3604 Finally, the message also can happen under the C</x> regex modifier when the
3605 C<\N> is separated by spaces from the C<{>, in which case, remove the spaces.
3607 /\N {SPACE}/x; # Wrong!
3610 =item No %s allowed while running setuid
3612 (F) Certain operations are deemed to be too insecure for a setuid or
3613 setgid script to even be allowed to attempt. Generally speaking there
3614 will be another way to do what you want that is, if not secure, at least
3615 securable. See L<perlsec>.
3617 =item NO-BREAK SPACE in a charnames alias definition is deprecated
3619 (D deprecated) You defined a character name which contained a no-break
3620 space character. Change it to a regular space. Usually these names are
3621 defined in the C<:alias> import argument to C<use charnames>, but they
3622 could be defined by a translator installed into C<$^H{charnames}>. See
3623 L<charnames/CUSTOM ALIASES>.
3625 =item No code specified for -%c
3627 (F) Perl's B<-e> and B<-E> command-line options require an argument. If
3628 you want to run an empty program, pass the empty string as a separate
3629 argument or run a program consisting of a single 0 or 1:
3635 =item No comma allowed after %s
3637 (F) A list operator that has a filehandle or "indirect object" is
3638 not allowed to have a comma between that and the following arguments.
3639 Otherwise it'd be just another one of the arguments.
3641 One possible cause for this is that you expected to have imported
3642 a constant to your name space with B<use> or B<import> while no such
3643 importing took place, it may for example be that your operating
3644 system does not support that particular constant. Hopefully you did
3645 use an explicit import list for the constants you expect to see;
3646 please see L<perlfunc/use> and L<perlfunc/import>. While an
3647 explicit import list would probably have caught this error earlier
3648 it naturally does not remedy the fact that your operating system
3649 still does not support that constant. Maybe you have a typo in
3650 the constants of the symbol import list of B<use> or B<import> or in the
3651 constant name at the line where this error was triggered?
3653 =item No command into which to pipe on command line
3655 (F) An error peculiar to VMS. Perl handles its own command line
3656 redirection, and found a '|' at the end of the command line, so it
3657 doesn't know where you want to pipe the output from this command.
3659 =item No DB::DB routine defined
3661 (F) The currently executing code was compiled with the B<-d> switch, but
3662 for some reason the current debugger (e.g. F<perl5db.pl> or a C<Devel::>
3663 module) didn't define a routine to be called at the beginning of each
3666 =item No dbm on this machine
3668 (P) This is counted as an internal error, because every machine should
3669 supply dbm nowadays, because Perl comes with SDBM. See L<SDBM_File>.
3671 =item No DB::sub routine defined
3673 (F) The currently executing code was compiled with the B<-d> switch, but
3674 for some reason the current debugger (e.g. F<perl5db.pl> or a C<Devel::>
3675 module) didn't define a C<DB::sub> routine to be called at the beginning
3676 of each ordinary subroutine call.
3678 =item No directory specified for -I
3680 (F) The B<-I> command-line switch requires a directory name as part of the
3681 I<same> argument. Use B<-Ilib>, for instance. B<-I lib> won't work.
3683 =item No error file after 2> or 2>> on command line
3685 (F) An error peculiar to VMS. Perl handles its own command line
3686 redirection, and found a '2>' or a '2>>' on the command line, but can't
3687 find the name of the file to which to write data destined for stderr.
3689 =item No group ending character '%c' found in template
3691 (F) A pack or unpack template has an opening '(' or '[' without its
3692 matching counterpart. See L<perlfunc/pack>.
3694 =item No input file after < on command line
3696 (F) An error peculiar to VMS. Perl handles its own command line
3697 redirection, and found a '<' on the command line, but can't find the
3698 name of the file from which to read data for stdin.
3700 =item No next::method '%s' found for %s
3702 (F) C<next::method> found no further instances of this method name
3703 in the remaining packages of the MRO of this class. If you don't want
3704 it throwing an exception, use C<maybe::next::method>
3705 or C<next::can>. See L<mro>.
3707 =item Non-finite repeat count does nothing
3709 (W numeric) You tried to execute the
3710 L<C<x>|perlop/Multiplicative Operators> repetition operator C<Inf> (or
3711 C<-Inf>) or C<NaN> times, which doesn't make sense.
3713 =item Non-hex character in regex; marked by S<<-- HERE> in m/%s/
3715 (F) In a regular expression, there was a non-hexadecimal character where
3716 a hex one was expected, like
3721 =item Non-octal character in regex; marked by S<<-- HERE> in m/%s/
3723 (F) In a regular expression, there was a non-octal character where
3724 an octal one was expected, like
3728 =item Non-octal character '%c'. Resolved as "%s"
3730 (W digit) In parsing an octal numeric constant, a character was
3731 unexpectedly encountered that isn't octal. The resulting value
3734 =item "no" not allowed in expression
3736 (F) The "no" keyword is recognized and executed at compile time, and
3737 returns no useful value. See L<perlmod>.
3739 =item Non-string passed as bitmask
3741 (W misc) A number has been passed as a bitmask argument to select().
3742 Use the vec() function to construct the file descriptor bitmasks for
3743 select. See L<perlfunc/select>.
3745 =item No output file after > on command line
3747 (F) An error peculiar to VMS. Perl handles its own command line
3748 redirection, and found a lone '>' at the end of the command line, so it
3749 doesn't know where you wanted to redirect stdout.
3751 =item No output file after > or >> on command line
3753 (F) An error peculiar to VMS. Perl handles its own command line
3754 redirection, and found a '>' or a '>>' on the command line, but can't
3755 find the name of the file to which to write data destined for stdout.
3757 =item No package name allowed for variable %s in "our"
3759 (F) Fully qualified variable names are not allowed in "our"
3760 declarations, because that doesn't make much sense under existing
3761 semantics. Such syntax is reserved for future extensions.
3763 =item No Perl script found in input
3765 (F) You called C<perl -x>, but no line was found in the file beginning
3766 with #! and containing the word "perl".
3768 =item No setregid available
3770 (F) Configure didn't find anything resembling the setregid() call for
3773 =item No setreuid available
3775 (F) Configure didn't find anything resembling the setreuid() call for
3778 =item No such class %s
3780 (F) You provided a class qualifier in a "my", "our" or "state"
3781 declaration, but this class doesn't exist at this point in your program.
3783 =item No such class field "%s" in variable %s of type %s
3785 (F) You tried to access a key from a hash through the indicated typed
3786 variable but that key is not allowed by the package of the same type.
3787 The indicated package has restricted the set of allowed keys using the
3790 =item No such hook: %s
3792 (F) You specified a signal hook that was not recognized by Perl.
3793 Currently, Perl accepts C<__DIE__> and C<__WARN__> as valid signal hooks.
3795 =item No such pipe open
3797 (P) An error peculiar to VMS. The internal routine my_pclose() tried to
3798 close a pipe which hadn't been opened. This should have been caught
3799 earlier as an attempt to close an unopened filehandle.
3801 =item No such signal: SIG%s
3803 (W signal) You specified a signal name as a subscript to %SIG that was
3804 not recognized. Say C<kill -l> in your shell to see the valid signal
3805 names on your system.
3807 =item Not a CODE reference
3809 (F) Perl was trying to evaluate a reference to a code value (that is, a
3810 subroutine), but found a reference to something else instead. You can
3811 use the ref() function to find out what kind of ref it really was. See
3814 =item Not a GLOB reference
3816 (F) Perl was trying to evaluate a reference to a "typeglob" (that is, a
3817 symbol table entry that looks like C<*foo>), but found a reference to
3818 something else instead. You can use the ref() function to find out what
3819 kind of ref it really was. See L<perlref>.
3821 =item Not a HASH reference
3823 (F) Perl was trying to evaluate a reference to a hash value, but found a
3824 reference to something else instead. You can use the ref() function to
3825 find out what kind of ref it really was. See L<perlref>.
3827 =item Not an ARRAY reference
3829 (F) Perl was trying to evaluate a reference to an array value, but found
3830 a reference to something else instead. You can use the ref() function
3831 to find out what kind of ref it really was. See L<perlref>.
3833 =item Not an unblessed ARRAY reference
3835 (F) You passed a reference to a blessed array to C<push>, C<shift> or
3836 another array function. These only accept unblessed array references
3837 or arrays beginning explicitly with C<@>.
3839 =item Not a SCALAR reference
3841 (F) Perl was trying to evaluate a reference to a scalar value, but found
3842 a reference to something else instead. You can use the ref() function
3843 to find out what kind of ref it really was. See L<perlref>.
3845 =item Not a subroutine reference
3847 (F) Perl was trying to evaluate a reference to a code value (that is, a
3848 subroutine), but found a reference to something else instead. You can
3849 use the ref() function to find out what kind of ref it really was. See
3852 =item Not a subroutine reference in overload table
3854 (F) An attempt was made to specify an entry in an overloading table that
3855 doesn't somehow point to a valid subroutine. See L<overload>.
3857 =item Not enough arguments for %s
3859 (F) The function requires more arguments than you specified.
3861 =item Not enough format arguments
3863 (W syntax) A format specified more picture fields than the next line
3864 supplied. See L<perlform>.
3868 (A) You've accidentally run your script through the Bourne shell instead
3869 of Perl. Check the #! line, or manually feed your script into Perl
3872 =item (?[...]) not valid in locale in regex; marked by S<<-- HERE> in m/%s/
3874 (F) C<(?[...])> cannot be used within the scope of a C<S<use locale>> or with
3875 an C</l> regular expression modifier, as that would require deferring
3876 to run-time the calculation of what it should evaluate to, and it is
3877 regex compile-time only.
3879 =item no UTC offset information; assuming local time is UTC
3881 (S) A warning peculiar to VMS. Perl was unable to find the local
3882 timezone offset, so it's assuming that local system time is equivalent
3883 to UTC. If it's not, define the logical name
3884 F<SYS$TIMEZONE_DIFFERENTIAL> to translate to the number of seconds which
3885 need to be added to UTC to get local time.
3887 =item NULL OP IN RUN
3889 (S debugging) Some internal routine called run() with a null opcode
3892 =item Null picture in formline
3894 (F) The first argument to formline must be a valid format picture
3895 specification. It was found to be empty, which probably means you
3896 supplied it an uninitialized value. See L<perlform>.
3900 (P) An attempt was made to realloc NULL.
3902 =item NULL regexp argument
3904 (P) The internal pattern matching routines blew it big time.
3906 =item NULL regexp parameter
3908 (P) The internal pattern matching routines are out of their gourd.
3910 =item Number too long
3912 (F) Perl limits the representation of decimal numbers in programs to
3913 about 250 characters. You've exceeded that length. Future
3914 versions of Perl are likely to eliminate this arbitrary limitation. In
3915 the meantime, try using scientific notation (e.g. "1e6" instead of
3918 =item Number with no digits
3920 (F) Perl was looking for a number but found nothing that looked like
3921 a number. This happens, for example with C<\o{}>, with no number between
3924 =item Octal number > 037777777777 non-portable
3926 (W portable) The octal number you specified is larger than 2**32-1
3927 (4294967295) and therefore non-portable between systems. See
3928 L<perlport> for more on portability concerns.
3930 =item Odd name/value argument for subroutine
3932 (F) A subroutine using a slurpy hash parameter in its signature
3933 received an odd number of arguments to populate the hash. It requires
3934 the arguments to be paired, with the same number of keys as values.
3935 The caller of the subroutine is presumably at fault. Inconveniently,
3936 this error will be reported at the location of the subroutine, not that
3939 =item Odd number of arguments for overload::constant
3941 (W overload) The call to overload::constant contained an odd number of
3942 arguments. The arguments should come in pairs.
3944 =item Odd number of elements in anonymous hash
3946 (W misc) You specified an odd number of elements to initialize a hash,
3947 which is odd, because hashes come in key/value pairs.
3949 =item Odd number of elements in hash assignment
3951 (W misc) You specified an odd number of elements to initialize a hash,
3952 which is odd, because hashes come in key/value pairs.
3954 =item Offset outside string
3956 (F)(W layer) You tried to do a read/write/send/recv/seek operation
3957 with an offset pointing outside the buffer. This is difficult to
3958 imagine. The sole exceptions to this are that zero padding will
3959 take place when going past the end of the string when either
3960 C<sysread()>ing a file, or when seeking past the end of a scalar opened
3961 for I/O (in anticipation of future reads and to imitate the behavior
3964 =item %s() on unopened %s
3966 (W unopened) An I/O operation was attempted on a filehandle that was
3967 never initialized. You need to do an open(), a sysopen(), or a socket()
3968 call, or call a constructor from the FileHandle package.
3970 =item -%s on unopened filehandle %s
3972 (W unopened) You tried to invoke a file test operator on a filehandle
3973 that isn't open. Check your control flow. See also L<perlfunc/-X>.
3977 (S internal) An internal warning that the grammar is screwed up.
3981 (S internal) An internal warning that the grammar is screwed up.
3983 =item Opening dirhandle %s also as a file
3985 (D io, deprecated) You used open() to associate a filehandle to
3986 a symbol (glob or scalar) that already holds a dirhandle.
3987 Although legal, this idiom might render your code confusing
3990 =item Opening filehandle %s also as a directory
3992 (D io, deprecated) You used opendir() to associate a dirhandle to
3993 a symbol (glob or scalar) that already holds a filehandle.
3994 Although legal, this idiom might render your code confusing
3997 =item Operand with no preceding operator in regex; marked by S<<-- HERE> in
4000 (F) You wrote something like
4002 (?[ \p{Digit} \p{Thai} ])
4004 There are two operands, but no operator giving how you want to combine
4007 =item Operation "%s": no method found, %s
4009 (F) An attempt was made to perform an overloaded operation for which no
4010 handler was defined. While some handlers can be autogenerated in terms
4011 of other handlers, there is no default handler for any operation, unless
4012 the C<fallback> overloading key is specified to be true. See L<overload>.
4014 =item Operation "%s" returns its argument for non-Unicode code point 0x%X
4016 (S non_unicode) You performed an operation requiring Unicode semantics
4017 on a code point that is not in Unicode, so what it should do is not
4018 defined. Perl has chosen to have it do nothing, and warn you.
4020 If the operation shown is "ToFold", it means that case-insensitive
4021 matching in a regular expression was done on the code point.
4023 If you know what you are doing you can turn off this warning by
4024 C<no warnings 'non_unicode';>.
4026 =item Operation "%s" returns its argument for UTF-16 surrogate U+%X
4028 (S surrogate) You performed an operation requiring Unicode
4029 semantics on a Unicode surrogate. Unicode frowns upon the use
4030 of surrogates for anything but storing strings in UTF-16, but
4031 semantics are (reluctantly) defined for the surrogates, and
4032 they are to do nothing for this operation. Because the use of
4033 surrogates can be dangerous, Perl warns.
4035 If the operation shown is "ToFold", it means that case-insensitive
4036 matching in a regular expression was done on the code point.
4038 If you know what you are doing you can turn off this warning by
4039 C<no warnings 'surrogate';>.
4041 =item Operator or semicolon missing before %s
4043 (S ambiguous) You used a variable or subroutine call where the parser
4044 was expecting an operator. The parser has assumed you really meant to
4045 use an operator, but this is highly likely to be incorrect. For
4046 example, if you say "*foo *foo" it will be interpreted as if you said
4049 =item Optional parameter lacks default expression
4051 (F) In a subroutine signature, you wrote something like "$a =", making a
4052 named optional parameter without a default value. A nameless optional
4053 parameter is permitted to have no default value, but a named one must
4054 have a specific default. You probably want "$a = undef".
4056 =item "our" variable %s redeclared
4058 (W misc) You seem to have already declared the same global once before
4059 in the current lexical scope.
4061 =item Out of memory!
4063 (X) The malloc() function returned 0, indicating there was insufficient
4064 remaining memory (or virtual memory) to satisfy the request. Perl has
4065 no option but to exit immediately.
4067 At least in Unix you may be able to get past this by increasing your
4068 process datasize limits: in csh/tcsh use C<limit> and
4069 C<limit datasize n> (where C<n> is the number of kilobytes) to check
4070 the current limits and change them, and in ksh/bash/zsh use C<ulimit -a>
4071 and C<ulimit -d n>, respectively.
4073 =item Out of memory during %s extend
4075 (X) An attempt was made to extend an array, a list, or a string beyond
4076 the largest possible memory allocation.
4078 =item Out of memory during "large" request for %s
4080 (F) The malloc() function returned 0, indicating there was insufficient
4081 remaining memory (or virtual memory) to satisfy the request. However,
4082 the request was judged large enough (compile-time default is 64K), so a
4083 possibility to shut down by trapping this error is granted.
4085 =item Out of memory during request for %s
4087 (X)(F) The malloc() function returned 0, indicating there was
4088 insufficient remaining memory (or virtual memory) to satisfy the
4091 The request was judged to be small, so the possibility to trap it
4092 depends on the way perl was compiled. By default it is not trappable.
4093 However, if compiled for this, Perl may use the contents of C<$^M> as an
4094 emergency pool after die()ing with this message. In this case the error
4095 is trappable I<once>, and the error message will include the line and file
4096 where the failed request happened.
4098 =item Out of memory during ridiculously large request
4100 (F) You can't allocate more than 2^31+"small amount" bytes. This error
4101 is most likely to be caused by a typo in the Perl program. e.g.,
4102 C<$arr[time]> instead of C<$arr[$time]>.
4104 =item Out of memory for yacc stack
4106 (F) The yacc parser wanted to grow its stack so it could continue
4107 parsing, but realloc() wouldn't give it more memory, virtual or
4110 =item '.' outside of string in pack
4112 (F) The argument to a '.' in your template tried to move the working
4113 position to before the start of the packed string being built.
4115 =item '@' outside of string in unpack
4117 (F) You had a template that specified an absolute position outside
4118 the string being unpacked. See L<perlfunc/pack>.
4120 =item '@' outside of string with malformed UTF-8 in unpack
4122 (F) You had a template that specified an absolute position outside
4123 the string being unpacked. The string being unpacked was also invalid
4124 UTF-8. See L<perlfunc/pack>.
4126 =item overload arg '%s' is invalid
4128 (W overload) The L<overload> pragma was passed an argument it did not
4129 recognize. Did you mistype an operator?
4131 =item Overloaded dereference did not return a reference
4133 (F) An object with an overloaded dereference operator was dereferenced,
4134 but the overloaded operation did not return a reference. See
4137 =item Overloaded qr did not return a REGEXP
4139 (F) An object with a C<qr> overload was used as part of a match, but the
4140 overloaded operation didn't return a compiled regexp. See L<overload>.
4142 =item %s package attribute may clash with future reserved word: %s
4144 (W reserved) A lowercase attribute name was used that had a
4145 package-specific handler. That name might have a meaning to Perl itself
4146 some day, even though it doesn't yet. Perhaps you should use a
4147 mixed-case attribute name, instead. See L<attributes>.
4149 =item pack/unpack repeat count overflow
4151 (F) You can't specify a repeat count so large that it overflows your
4152 signed integers. See L<perlfunc/pack>.
4156 (W io) A single call to write() produced more lines than can fit on a
4157 page. See L<perlform>.
4161 (P) An internal error.
4163 =item panic: attempt to call %s in %s
4165 (P) One of the file test operators entered a code branch that calls
4166 an ACL related-function, but that function is not available on this
4167 platform. Earlier checks mean that it should not be possible to
4168 enter this branch on this platform.
4170 =item panic: child pseudo-process was never scheduled
4172 (P) A child pseudo-process in the ithreads implementation on Windows
4173 was not scheduled within the time period allowed and therefore was not
4174 able to initialize properly.
4176 =item panic: ck_grep, type=%u
4178 (P) Failed an internal consistency check trying to compile a grep.
4180 =item panic: ck_split, type=%u
4182 (P) Failed an internal consistency check trying to compile a split.
4184 =item panic: corrupt saved stack index %ld
4186 (P) The savestack was requested to restore more localized values than
4187 there are in the savestack.
4189 =item panic: del_backref
4191 (P) Failed an internal consistency check while trying to reset a weak
4196 (P) We popped the context stack to an eval context, and then discovered
4197 it wasn't an eval context.
4199 =item panic: do_subst
4201 (P) The internal pp_subst() routine was called with invalid operational
4204 =item panic: do_trans_%s
4206 (P) The internal do_trans routines were called with invalid operational
4209 =item panic: fold_constants JMPENV_PUSH returned %d
4211 (P) While attempting folding constants an exception other than an C<eval>
4214 =item panic: frexp: %f
4216 (P) The library function frexp() failed, making printf("%f") impossible.
4218 =item panic: goto, type=%u, ix=%ld
4220 (P) We popped the context stack to a context with the specified label,
4221 and then discovered it wasn't a context we know how to do a goto in.
4223 =item panic: gp_free failed to free glob pointer
4225 (P) The internal routine used to clear a typeglob's entries tried
4226 repeatedly, but each time something re-created entries in the glob.
4227 Most likely the glob contains an object with a reference back to
4228 the glob and a destructor that adds a new object to the glob.
4230 =item panic: INTERPCASEMOD, %s
4232 (P) The lexer got into a bad state at a case modifier.
4234 =item panic: INTERPCONCAT, %s
4236 (P) The lexer got into a bad state parsing a string with brackets.
4238 =item panic: kid popen errno read
4240 (F) A forked child returned an incomprehensible message about its errno.
4242 =item panic: last, type=%u
4244 (P) We popped the context stack to a block context, and then discovered
4245 it wasn't a block context.
4247 =item panic: leave_scope clearsv
4249 (P) A writable lexical variable became read-only somehow within the
4252 =item panic: leave_scope inconsistency %u
4254 (P) The savestack probably got out of sync. At least, there was an
4255 invalid enum on the top of it.
4257 =item panic: magic_killbackrefs
4259 (P) Failed an internal consistency check while trying to reset all weak
4260 references to an object.
4262 =item panic: malloc, %s
4264 (P) Something requested a negative number of bytes of malloc.
4266 =item panic: memory wrap
4268 (P) Something tried to allocate either more memory than possible or a
4271 =item panic: pad_alloc, %p!=%p
4273 (P) The compiler got confused about which scratch pad it was allocating
4274 and freeing temporaries and lexicals from.
4276 =item panic: pad_free curpad, %p!=%p
4278 (P) The compiler got confused about which scratch pad it was allocating
4279 and freeing temporaries and lexicals from.
4281 =item panic: pad_free po
4283 (P) A zero scratch pad offset was detected internally. An attempt was
4284 made to free a target that had not been allocated to begin with.
4286 =item panic: pad_reset curpad, %p!=%p
4288 (P) The compiler got confused about which scratch pad it was allocating
4289 and freeing temporaries and lexicals from.
4291 =item panic: pad_sv po
4293 (P) A zero scratch pad offset was detected internally. Most likely
4294 an operator needed a target but that target had not been allocated
4295 for whatever reason.
4297 =item panic: pad_swipe curpad, %p!=%p
4299 (P) The compiler got confused about which scratch pad it was allocating
4300 and freeing temporaries and lexicals from.
4302 =item panic: pad_swipe po
4304 (P) An invalid scratch pad offset was detected internally.
4306 =item panic: pp_iter, type=%u
4308 (P) The foreach iterator got called in a non-loop context frame.
4310 =item panic: pp_match%s
4312 (P) The internal pp_match() routine was called with invalid operational
4315 =item panic: pp_split, pm=%p, s=%p
4317 (P) Something terrible went wrong in setting up for the split.
4319 =item panic: realloc, %s
4321 (P) Something requested a negative number of bytes of realloc.
4323 =item panic: reference miscount on nsv in sv_replace() (%d != 1)
4325 (P) The internal sv_replace() function was handed a new SV with a
4326 reference count other than 1.
4328 =item panic: restartop in %s
4330 (P) Some internal routine requested a goto (or something like it), and
4331 didn't supply the destination.
4333 =item panic: return, type=%u
4335 (P) We popped the context stack to a subroutine or eval context, and
4336 then discovered it wasn't a subroutine or eval context.
4338 =item panic: scan_num, %s
4340 (P) scan_num() got called on something that wasn't a number.
4342 =item panic: Sequence (?{...}): no code block found in regex m/%s/
4344 (P) While compiling a pattern that has embedded (?{}) or (??{}) code
4345 blocks, perl couldn't locate the code block that should have already been
4346 seen and compiled by perl before control passed to the regex compiler.
4348 =item panic: strxfrm() gets absurd - a => %u, ab => %u
4350 (P) The interpreter's sanity check of the C function strxfrm() failed.
4351 In your current locale the returned transformation of the string "ab"
4352 is shorter than that of the string "a", which makes no sense.
4354 =item panic: sv_chop %s
4356 (P) The sv_chop() routine was passed a position that is not within the
4357 scalar's string buffer.
4359 =item panic: sv_insert, midend=%p, bigend=%p
4361 (P) The sv_insert() routine was told to remove more string than there
4364 =item panic: top_env
4366 (P) The compiler attempted to do a goto, or something weird like that.
4368 =item panic: unimplemented op %s (#%d) called
4370 (P) The compiler is screwed up and attempted to use an op that isn't
4371 permitted at run time.
4373 =item panic: utf16_to_utf8: odd bytelen
4375 (P) Something tried to call utf16_to_utf8 with an odd (as opposed
4376 to even) byte length.
4378 =item panic: utf16_to_utf8_reversed: odd bytelen
4380 (P) Something tried to call utf16_to_utf8_reversed with an odd (as opposed
4381 to even) byte length.
4383 =item panic: yylex, %s
4385 (P) The lexer got into a bad state while processing a case modifier.
4387 =item Parentheses missing around "%s" list
4389 (W parenthesis) You said something like
4395 my ($foo, $bar) = @_;
4397 Remember that "my", "our", "local" and "state" bind tighter than comma.
4399 =item Parsing code internal error (%s)
4401 (F) Parsing code supplied by an extension violated the parser's API in
4404 =item Passing malformed UTF-8 to "%s" is deprecated
4406 (D deprecated, utf8) This message indicates a bug either in the Perl
4407 core or in XS code. Such code was trying to find out if a character,
4408 allegedly stored internally encoded as UTF-8, was of a given type, such
4409 as being punctuation or a digit. But the character was not encoded in
4410 legal UTF-8. The C<%s> is replaced by a string that can be used by
4411 knowledgeable people to determine what the type being checked against
4412 was. If C<utf8> warnings are enabled, a further message is raised,
4413 giving details of the malformation.
4415 =item Pattern subroutine nesting without pos change exceeded limit in regex
4417 (F) You used a pattern that uses too many nested subpattern calls without
4418 consuming any text. Restructure the pattern so text is consumed before
4419 the nesting limit is exceeded.
4421 =item C<-p> destination: %s
4423 (F) An error occurred during the implicit output invoked by the C<-p>
4424 command-line switch. (This output goes to STDOUT unless you've
4425 redirected it with select().)
4427 =item Perl API version %s of %s does not match %s
4429 (F) The XS module in question was compiled against a different incompatible
4430 version of Perl than the one that has loaded the XS module.
4432 =item Perl folding rules are not up-to-date for 0x%X; please use the perlbug
4433 utility to report; in regex; marked by S<<-- HERE> in m/%s/
4435 (S regexp) You used a regular expression with case-insensitive matching,
4436 and there is a bug in Perl in which the built-in regular expression
4437 folding rules are not accurate. This may lead to incorrect results.
4438 Please report this as a bug using the L<perlbug> utility.
4440 =item PerlIO layer ':win32' is experimental
4442 (S experimental::win32_perlio) The C<:win32> PerlIO layer is
4443 experimental. If you want to take the risk of using this layer,
4444 simply disable this warning:
4446 no warnings "experimental::win32_perlio";
4448 =item Perl_my_%s() not available
4450 (F) Your platform has very uncommon byte-order and integer size,
4451 so it was not possible to set up some or all fixed-width byte-order
4452 conversion functions. This is only a problem when you're using the
4453 '<' or '>' modifiers in (un)pack templates. See L<perlfunc/pack>.
4455 =item Perl %s required (did you mean %s?)--this is only %s, stopped
4457 (F) The code you are trying to run has asked for a newer version of
4458 Perl than you are running. Perhaps C<use 5.10> was written instead
4459 of C<use 5.010> or C<use v5.10>. Without the leading C<v>, the number is
4460 interpreted as a decimal, with every three digits after the
4461 decimal point representing a part of the version number. So 5.10
4462 is equivalent to v5.100.
4464 =item Perl %s required--this is only %s, stopped
4466 (F) The module in question uses features of a version of Perl more
4467 recent than the currently running version. How long has it been since
4468 you upgraded, anyway? See L<perlfunc/require>.
4470 =item PERL_SH_DIR too long
4472 (F) An error peculiar to OS/2. PERL_SH_DIR is the directory to find the
4473 C<sh>-shell in. See "PERL_SH_DIR" in L<perlos2>.
4475 =item PERL_SIGNALS illegal: "%s"
4477 (X) See L<perlrun/PERL_SIGNALS> for legal values.
4479 =item Perls since %s too modern--this is %s, stopped
4481 (F) The code you are trying to run claims it will not run
4482 on the version of Perl you are using because it is too new.
4483 Maybe the code needs to be updated, or maybe it is simply
4484 wrong and the version check should just be removed.
4486 =item perl: warning: Non hex character in '$ENV{PERL_HASH_SEED}', seed only partially set
4488 (S) PERL_HASH_SEED should match /^\s*(?:0x)?[0-9a-fA-F]+\s*\z/ but it
4489 contained a non hex character. This could mean you are not using the
4490 hash seed you think you are.
4492 =item perl: warning: Setting locale failed.
4494 (S) The whole warning message will look something like:
4496 perl: warning: Setting locale failed.
4497 perl: warning: Please check that your locale settings:
4500 are supported and installed on your system.
4501 perl: warning: Falling back to the standard locale ("C").
4503 Exactly what were the failed locale settings varies. In the above the
4504 settings were that the LC_ALL was "En_US" and the LANG had no value.
4505 This error means that Perl detected that you and/or your operating
4506 system supplier and/or system administrator have set up the so-called
4507 locale system but Perl could not use those settings. This was not
4508 dead serious, fortunately: there is a "default locale" called "C" that
4509 Perl can and will use, and the script will be run. Before you really
4510 fix the problem, however, you will get the same error message each
4511 time you run Perl. How to really fix the problem can be found in
4512 L<perllocale> section B<LOCALE PROBLEMS>.
4514 =item perl: warning: strange setting in '$ENV{PERL_PERTURB_KEYS}': '%s'
4516 (S) Perl was run with the environment variable PERL_PERTURB_KEYS defined
4517 but containing an unexpected value. The legal values of this setting
4520 Numeric | String | Result
4521 --------+---------------+-----------------------------------------
4522 0 | NO | Disables key traversal randomization
4523 1 | RANDOM | Enables full key traversal randomization
4524 2 | DETERMINISTIC | Enables repeatable key traversal
4527 Both numeric and string values are accepted, but note that string values are
4528 case sensitive. The default for this setting is "RANDOM" or 1.
4530 =item pid %x not a child
4532 (W exec) A warning peculiar to VMS. Waitpid() was asked to wait for a
4533 process which isn't a subprocess of the current process. While this is
4534 fine from VMS' perspective, it's probably not what you intended.
4536 =item 'P' must have an explicit size in unpack
4538 (F) The unpack format P must have an explicit size, not "*".
4540 =item pop on reference is experimental
4542 (S experimental::autoderef) C<pop> with a scalar argument is experimental
4543 and may change or be removed in a future Perl version. If you want to
4544 take the risk of using this feature, simply disable this warning:
4546 no warnings "experimental::autoderef";
4548 =item POSIX class [:%s:] unknown in regex; marked by S<< <-- HERE in m/%s/ >>
4550 (F) The class in the character class [: :] syntax is unknown. The S<<-- HERE>
4551 shows whereabouts in the regular expression the problem was discovered.
4552 Note that the POSIX character classes do B<not> have the C<is> prefix
4553 the corresponding C interfaces have: in other words, it's C<[[:print:]]>,
4554 not C<isprint>. See L<perlre>.
4556 =item POSIX getpgrp can't take an argument
4558 (F) Your system has POSIX getpgrp(), which takes no argument, unlike
4559 the BSD version, which takes a pid.
4561 =item POSIX syntax [%c %c] belongs inside character classes in regex; marked by
4562 S<<-- HERE> in m/%s/
4564 (W regexp) The character class constructs [: :], [= =], and [. .] go
4565 I<inside> character classes, the [] are part of the construct, for example:
4566 /[012[:alpha:]345]/. Note that [= =] and [. .] are not currently
4567 implemented; they are simply placeholders for future extensions and
4568 will cause fatal errors. The S<<-- HERE> shows whereabouts in the regular
4569 expression the problem was discovered. See L<perlre>.
4571 =item POSIX syntax [. .] is reserved for future extensions in regex; marked by
4572 S<<-- HERE> in m/%s/
4574 (F) Within regular expression character classes ([]) the syntax beginning
4575 with "[." and ending with ".]" is reserved for future extensions. If you
4576 need to represent those character sequences inside a regular expression
4577 character class, just quote the square brackets with the backslash: "\[."
4578 and ".\]". The S<<-- HERE> shows whereabouts in the regular expression the
4579 problem was discovered. See L<perlre>.
4581 =item POSIX syntax [= =] is reserved for future extensions in regex; marked by
4582 S<<-- HERE> in m/%s/
4584 (F) Within regular expression character classes ([]) the syntax beginning
4585 with "[=" and ending with "=]" is reserved for future extensions. If you
4586 need to represent those character sequences inside a regular expression
4587 character class, just quote the square brackets with the backslash: "\[="
4588 and "=\]". The S<<-- HERE> shows whereabouts in the regular expression the
4589 problem was discovered. See L<perlre>.
4591 =item Possible attempt to put comments in qw() list
4593 (W qw) qw() lists contain items separated by whitespace; as with literal
4594 strings, comment characters are not ignored, but are instead treated as
4595 literal data. (You may have used different delimiters than the
4596 parentheses shown here; braces are also frequently used.)
4598 You probably wrote something like this:
4605 when you should have written this:
4612 If you really want comments, build your list the
4613 old-fashioned way, with quotes and commas:
4617 'b', # another comment
4620 =item Possible attempt to separate words with commas
4622 (W qw) qw() lists contain items separated by whitespace; therefore
4623 commas aren't needed to separate the items. (You may have used
4624 different delimiters than the parentheses shown here; braces are also
4627 You probably wrote something like this:
4631 which puts literal commas into some of the list items. Write it without
4632 commas if you don't want them to appear in your data:
4636 =item Possible memory corruption: %s overflowed 3rd argument
4638 (F) An ioctl() or fcntl() returned more than Perl was bargaining for.
4639 Perl guesses a reasonable buffer size, but puts a sentinel byte at the
4640 end of the buffer just in case. This sentinel byte got clobbered, and
4641 Perl assumes that memory is now corrupted. See L<perlfunc/ioctl>.
4643 =item Possible precedence issue with control flow operator
4645 (W syntax) There is a possible problem with the mixing of a control
4646 flow operator (e.g. C<return>) and a low-precedence operator like
4649 sub { return $a or $b; }
4653 sub { (return $a) or $b; }
4655 Which is effectively just:
4659 Either use parentheses or the high-precedence variant of the operator.
4661 Note this may be also triggered for constructs like:
4665 =item Possible precedence problem on bitwise %c operator
4667 (W precedence) Your program uses a bitwise logical operator in conjunction
4668 with a numeric comparison operator, like this :
4670 if ($x & $y == 0) { ... }
4672 This expression is actually equivalent to C<$x & ($y == 0)>, due to the
4673 higher precedence of C<==>. This is probably not what you want. (If you
4674 really meant to write this, disable the warning, or, better, put the
4675 parentheses explicitly and write C<$x & ($y == 0)>).
4677 =item Possible unintended interpolation of $\ in regex
4679 (W ambiguous) You said something like C<m/$\/> in a regex.
4680 The regex C<m/foo$\s+bar/m> translates to: match the word 'foo', the output
4681 record separator (see L<perlvar/$\>) and the letter 's' (one time or more)
4682 followed by the word 'bar'.
4684 If this is what you intended then you can silence the warning by using
4685 C<m/${\}/> (for example: C<m/foo${\}s+bar/>).
4687 If instead you intended to match the word 'foo' at the end of the line
4688 followed by whitespace and the word 'bar' on the next line then you can use
4689 C<m/$(?)\/> (for example: C<m/foo$(?)\s+bar/>).
4691 =item Possible unintended interpolation of %s in string
4693 (W ambiguous) You said something like '@foo' in a double-quoted string
4694 but there was no array C<@foo> in scope at the time. If you wanted a
4695 literal @foo, then write it as \@foo; otherwise find out what happened
4696 to the array you apparently lost track of.
4698 =item Postfix dereference is experimental
4700 (S experimental::postderef) This warning is emitted if you use
4701 the experimental postfix dereference syntax. Simply suppress the
4702 warning if you want to use the feature, but know that in doing
4703 so you are taking the risk of using an experimental feature which
4704 may change or be removed in a future Perl version:
4706 no warnings "experimental::postderef";
4707 use feature "postderef", "postderef_qq";
4713 =item Precedence problem: open %s should be open(%s)
4715 (S precedence) The old irregular construct
4719 is now misinterpreted as
4723 because of the strict regularization of Perl 5's grammar into unary and
4724 list operators. (The old open was a little of both.) You must put
4725 parentheses around the filehandle, or use the new "or" operator instead
4728 =item Premature end of script headers
4732 =item printf() on closed filehandle %s
4734 (W closed) The filehandle you're writing to got itself closed sometime
4735 before now. Check your control flow.
4737 =item print() on closed filehandle %s
4739 (W closed) The filehandle you're printing on got itself closed sometime
4740 before now. Check your control flow.
4742 =item Process terminated by SIG%s
4744 (W) This is a standard message issued by OS/2 applications, while *nix
4745 applications die in silence. It is considered a feature of the OS/2
4746 port. One can easily disable this by appropriate sighandlers, see
4747 L<perlipc/"Signals">. See also "Process terminated by SIGTERM/SIGINT"
4750 =item Property '%s' is unknown in regex; marked by S<<-- HERE> in m/%s/
4752 (F) The named property which you specified via C<\p> or C<\P> is not one
4753 known to Perl. Perhaps you misspelled the name? See
4754 L<perluniprops/Properties accessible through \p{} and \P{}>
4755 for a complete list of available official
4756 properties. If it is a L<user-defined property|perlunicode/User-Defined Character Properties>
4757 it must have been defined by the time the regular expression is
4760 =item Prototype after '%c' for %s : %s
4762 (W illegalproto) A character follows % or @ in a prototype. This is
4763 useless, since % and @ gobble the rest of the subroutine arguments.
4765 =item Prototype mismatch: %s vs %s
4767 (S prototype) The subroutine being declared or defined had previously been
4768 declared or defined with a different function prototype.
4770 =item Prototype not terminated
4772 (F) You've omitted the closing parenthesis in a function prototype
4775 =item Prototype '%s' overridden by attribute 'prototype(%s)' in %s
4777 (W prototype) A prototype was declared in both the parentheses after
4778 the sub name and via the prototype attribute. The prototype in
4779 parentheses is useless, since it will be replaced by the prototype
4780 from the attribute before it's ever used.
4782 =item push on reference is experimental
4784 (S experimental::autoderef) C<push> with a scalar argument is experimental
4785 and may change or be removed in a future Perl version. If you want to
4786 take the risk of using this feature, simply disable this warning:
4788 no warnings "experimental::autoderef";
4790 =item Quantifier follows nothing in regex; marked by S<< <-- HERE in m/%s/ >>
4792 (F) You started a regular expression with a quantifier. Backslash it if
4793 you meant it literally. The S<<-- HERE> shows whereabouts in the regular
4794 expression the problem was discovered. See L<perlre>.
4796 =item Quantifier in {,} bigger than %d in regex; marked by S<<-- HERE> in
4799 (F) There is currently a limit to the size of the min and max values of
4800 the {min,max} construct. The S<<-- HERE> shows whereabouts in the regular
4801 expression the problem was discovered. See L<perlre>.
4803 =item Quantifier {n,m} with n > m can't match in regex
4805 =item Quantifier {n,m} with n > m can't match in regex; marked by
4806 S<<-- HERE> in m/%s/
4808 (W regexp) Minima should be less than or equal to maxima. If you really
4809 want your regexp to match something 0 times, just put {0}.
4811 =item Quantifier unexpected on zero-length expression in regex m/%s/
4813 (W regexp) You applied a regular expression quantifier in a place where
4814 it makes no sense, such as on a zero-width assertion. Try putting the
4815 quantifier inside the assertion instead. For example, the way to match
4816 "abc" provided that it is followed by three repetitions of "xyz" is
4817 C</abc(?=(?:xyz){3})/>, not C</abc(?=xyz){3}/>.
4819 =item Range iterator outside integer range
4821 (F) One (or both) of the numeric arguments to the range operator ".."
4822 are outside the range which can be represented by integers internally.
4823 One possible workaround is to force Perl to use magical string increment
4824 by prepending "0" to your numbers.
4826 =item readdir() attempted on invalid dirhandle %s
4828 (W io) The dirhandle you're reading from is either closed or not really
4829 a dirhandle. Check your control flow.
4831 =item readline() on closed filehandle %s
4833 (W closed) The filehandle you're reading from got itself closed sometime
4834 before now. Check your control flow.
4836 =item read() on closed filehandle %s
4838 (W closed) You tried to read from a closed filehandle.
4840 =item read() on unopened filehandle %s
4842 (W unopened) You tried to read from a filehandle that was never opened.
4844 =item Reallocation too large: %x
4846 (F) You can't allocate more than 64K on an MS-DOS machine.
4848 =item realloc() of freed memory ignored
4850 (S malloc) An internal routine called realloc() on something that had
4853 =item Recompile perl with B<-D>DEBUGGING to use B<-D> switch
4855 (S debugging) You can't use the B<-D> option unless the code to produce
4856 the desired output is compiled into Perl, which entails some overhead,
4857 which is why it's currently left out of your copy.
4859 =item Recursive call to Perl_load_module in PerlIO_find_layer
4861 (P) It is currently not permitted to load modules when creating
4862 a filehandle inside an %INC hook. This can happen with C<open my
4863 $fh, '<', \$scalar>, which implicitly loads PerlIO::scalar. Try
4864 loading PerlIO::scalar explicitly first.
4866 =item Recursive inheritance detected in package '%s'
4868 (F) While calculating the method resolution order (MRO) of a package, Perl
4869 believes it found an infinite loop in the C<@ISA> hierarchy. This is a
4870 crude check that bails out after 100 levels of C<@ISA> depth.
4872 =item Redundant argument in %s
4874 (W redundant) You called a function with more arguments than other
4875 arguments you supplied indicated would be needed. Currently only
4876 emitted when a printf-type format required fewer arguments than were
4877 supplied, but might be used in the future for e.g. L<perlfunc/pack>.
4879 =item refcnt_dec: fd %d%s
4881 =item refcnt: fd %d%s
4883 =item refcnt_inc: fd %d%s
4885 (P) Perl's I/O implementation failed an internal consistency check. If
4886 you see this message, something is very wrong.
4888 =item Reference found where even-sized list expected
4890 (W misc) You gave a single reference where Perl was expecting a list
4891 with an even number of elements (for assignment to a hash). This
4892 usually means that you used the anon hash constructor when you meant
4893 to use parens. In any case, a hash requires key/value B<pairs>.
4895 %hash = { one => 1, two => 2, }; # WRONG
4896 %hash = [ qw/ an anon array / ]; # WRONG
4897 %hash = ( one => 1, two => 2, ); # right
4898 %hash = qw( one 1 two 2 ); # also fine
4900 =item Reference is already weak
4902 (W misc) You have attempted to weaken a reference that is already weak.
4903 Doing so has no effect.
4905 =item Reference to invalid group 0 in regex; marked by S<<-- HERE> in m/%s/
4907 (F) You used C<\g0> or similar in a regular expression. You may refer
4908 to capturing parentheses only with strictly positive integers
4909 (normal backreferences) or with strictly negative integers (relative
4910 backreferences). Using 0 does not make sense.
4912 =item Reference to nonexistent group in regex; marked by S<<-- HERE> in
4915 (F) You used something like C<\7> in your regular expression, but there are
4916 not at least seven sets of capturing parentheses in the expression. If
4917 you wanted to have the character with ordinal 7 inserted into the regular
4918 expression, prepend zeroes to make it three digits long: C<\007>
4920 The <-- HERE shows whereabouts in the regular expression the problem was
4923 =item Reference to nonexistent named group in regex; marked by S<<-- HERE>
4926 (F) You used something like C<\k'NAME'> or C<< \k<NAME> >> in your regular
4927 expression, but there is no corresponding named capturing parentheses
4928 such as C<(?'NAME'...)> or C<< (?<NAME>...) >>. Check if the name has been
4929 spelled correctly both in the backreference and the declaration.
4931 The <-- HERE shows whereabouts in the regular expression the problem was
4934 =item Reference to nonexistent or unclosed group in regex; marked by
4935 S<<-- HERE> in m/%s/
4937 (F) You used something like C<\g{-7}> in your regular expression, but there
4938 are not at least seven sets of closed capturing parentheses in the
4939 expression before where the C<\g{-7}> was located.
4941 The <-- HERE shows whereabouts in the regular expression the problem was
4944 =item regexp memory corruption
4946 (P) The regular expression engine got confused by what the regular
4947 expression compiler gave it.
4949 =item Regexp modifier "/%c" may appear a maximum of twice
4951 =item Regexp modifier "%c" may appear a maximum of twice in regex; marked
4952 by S<<-- HERE> in m/%s/
4954 (F) The regular expression pattern had too many occurrences
4955 of the specified modifier. Remove the extraneous ones.
4957 =item Regexp modifier "%c" may not appear after the "-" in regex; marked by <--
4960 (F) Turning off the given modifier has the side effect of turning on
4961 another one. Perl currently doesn't allow this. Reword the regular
4962 expression to use the modifier you want to turn on (and place it before
4963 the minus), instead of the one you want to turn off.
4965 =item Regexp modifier "/%c" may not appear twice
4967 =item Regexp modifier "%c" may not appear twice in regex; marked by <--
4970 (F) The regular expression pattern had too many occurrences
4971 of the specified modifier. Remove the extraneous ones.
4973 =item Regexp modifiers "/%c" and "/%c" are mutually exclusive
4975 =item Regexp modifiers "%c" and "%c" are mutually exclusive in regex;
4976 marked by S<<-- HERE> in m/%s/
4978 (F) The regular expression pattern had more than one of these
4979 mutually exclusive modifiers. Retain only the modifier that is
4980 supposed to be there.
4982 =item Regexp out of space in regex m/%s/
4984 (P) A "can't happen" error, because safemalloc() should have caught it
4987 =item Repeated format line will never terminate (~~ and @#)
4989 (F) Your format contains the ~~ repeat-until-blank sequence and a
4990 numeric field that will never go blank so that the repetition never
4991 terminates. You might use ^# instead. See L<perlform>.
4993 =item Replacement list is longer than search list
4995 (W misc) You have used a replacement list that is longer than the
4996 search list. So the additional elements in the replacement list
4999 =item '%s' resolved to '\o{%s}%d'
5001 (W misc, regexp) You wrote something like C<\08>, or C<\179> in a
5002 double-quotish string. All but the last digit is treated as a single
5003 character, specified in octal. The last digit is the next character in
5004 the string. To tell Perl that this is indeed what you want, you can use
5005 the C<\o{ }> syntax, or use exactly three digits to specify the octal
5008 =item Reversed %s= operator
5010 (W syntax) You wrote your assignment operator backwards. The = must
5011 always come last, to avoid ambiguity with subsequent unary operators.
5013 =item rewinddir() attempted on invalid dirhandle %s
5015 (W io) The dirhandle you tried to do a rewinddir() on is either closed
5016 or not really a dirhandle. Check your control flow.
5018 =item Scalars leaked: %d
5020 (S internal) Something went wrong in Perl's internal bookkeeping
5021 of scalars: not all scalar variables were deallocated by the time
5022 Perl exited. What this usually indicates is a memory leak, which
5023 is of course bad, especially if the Perl program is intended to be
5026 =item Scalar value @%s[%s] better written as $%s[%s]
5028 (W syntax) You've used an array slice (indicated by @) to select a
5029 single element of an array. Generally it's better to ask for a scalar
5030 value (indicated by $). The difference is that C<$foo[&bar]> always
5031 behaves like a scalar, both when assigning to it and when evaluating its
5032 argument, while C<@foo[&bar]> behaves like a list when you assign to it,
5033 and provides a list context to its subscript, which can do weird things
5034 if you're expecting only one subscript.
5036 On the other hand, if you were actually hoping to treat the array
5037 element as a list, you need to look into how references work, because
5038 Perl will not magically convert between scalars and lists for you. See
5041 =item Scalar value @%s{%s} better written as $%s{%s}
5043 (W syntax) You've used a hash slice (indicated by @) to select a single
5044 element of a hash. Generally it's better to ask for a scalar value
5045 (indicated by $). The difference is that C<$foo{&bar}> always behaves
5046 like a scalar, both when assigning to it and when evaluating its
5047 argument, while C<@foo{&bar}> behaves like a list when you assign to it,
5048 and provides a list context to its subscript, which can do weird things
5049 if you're expecting only one subscript.
5051 On the other hand, if you were actually hoping to treat the hash element
5052 as a list, you need to look into how references work, because Perl will
5053 not magically convert between scalars and lists for you. See
5056 =item Search pattern not terminated
5058 (F) The lexer couldn't find the final delimiter of a // or m{}
5059 construct. Remember that bracketing delimiters count nesting level.
5060 Missing the leading C<$> from a variable C<$m> may cause this error.
5062 Note that since Perl 5.10.0 a // can also be the I<defined-or>
5063 construct, not just the empty search pattern. Therefore code written
5064 in Perl 5.10.0 or later that uses the // as the I<defined-or> can be
5065 misparsed by pre-5.10.0 Perls as a non-terminated search pattern.
5067 =item seekdir() attempted on invalid dirhandle %s
5069 (W io) The dirhandle you are doing a seekdir() on is either closed or not
5070 really a dirhandle. Check your control flow.
5072 =item %sseek() on unopened filehandle
5074 (W unopened) You tried to use the seek() or sysseek() function on a
5075 filehandle that was either never opened or has since been closed.
5077 =item select not implemented
5079 (F) This machine doesn't implement the select() system call.
5081 =item Self-ties of arrays and hashes are not supported
5083 (F) Self-ties are of arrays and hashes are not supported in
5084 the current implementation.
5086 =item Semicolon seems to be missing
5088 (W semicolon) A nearby syntax error was probably caused by a missing
5089 semicolon, or possibly some other missing operator, such as a comma.
5091 =item semi-panic: attempt to dup freed string
5093 (S internal) The internal newSVsv() routine was called to duplicate a
5094 scalar that had previously been marked as free.
5096 =item sem%s not implemented
5098 (F) You don't have System V semaphore IPC on your system.
5100 =item send() on closed socket %s
5102 (W closed) The socket you're sending to got itself closed sometime
5103 before now. Check your control flow.
5105 =item Sequence "\c{" invalid
5107 (F) These three characters may not appear in sequence in a
5108 double-quotish context. This message is raised only on non-ASCII
5109 platforms (a different error message is output on ASCII ones). If you
5110 were intending to specify a control character with this sequence, you'll
5111 have to use a different way to specify it.
5113 =item Sequence (? incomplete in regex; marked by S<<-- HERE> in m/%s/
5115 (F) A regular expression ended with an incomplete extension (?. The
5116 S<<-- HERE> shows whereabouts in the regular expression the problem was
5117 discovered. See L<perlre>.
5119 =item Sequence (?%c...) not implemented in regex; marked by S<<-- HERE> in
5122 (F) A proposed regular expression extension has the character reserved
5123 but has not yet been written. The S<<-- HERE> shows whereabouts in the
5124 regular expression the problem was discovered. See L<perlre>.
5126 =item Sequence (?%s...) not recognized in regex; marked by S<<-- HERE> in
5129 (F) You used a regular expression extension that doesn't make sense.
5130 The S<<-- HERE> shows whereabouts in the regular expression the problem was
5131 discovered. This may happen when using the C<(?^...)> construct to tell
5132 Perl to use the default regular expression modifiers, and you
5133 redundantly specify a default modifier. For other
5134 causes, see L<perlre>.
5136 =item Sequence (?#... not terminated in regex m/%s/
5138 (F) A regular expression comment must be terminated by a closing
5139 parenthesis. Embedded parentheses aren't allowed. See
5142 =item Sequence (?&... not terminated in regex; marked by S<<-- HERE> in
5145 (F) A named reference of the form C<(?&...)> was missing the final
5146 closing parenthesis after the name. The S<<-- HERE> shows whereabouts
5147 in the regular expression the problem was discovered.
5149 =item Sequence (?%c... not terminated in regex; marked by S<<-- HERE>
5152 (F) A named group of the form C<(?'...')> or C<< (?<...>) >> was missing the final
5153 closing quote or angle bracket. The S<<-- HERE> shows whereabouts in the
5154 regular expression the problem was discovered.
5156 =item Sequence (?(%c... not terminated in regex; marked by S<<-- HERE>
5159 (F) A named reference of the form C<(?('...')...)> or C<< (?(<...>)...) >> was
5160 missing the final closing quote or angle bracket after the name. The
5161 S<<-- HERE> shows whereabouts in the regular expression the problem was
5164 =item Sequence \%s... not terminated in regex; marked by S<<-- HERE> in
5167 (F) The regular expression expects a mandatory argument following the escape
5168 sequence and this has been omitted or incorrectly written.
5170 =item Sequence (?{...}) not terminated with ')'
5172 (F) The end of the perl code contained within the {...} must be
5173 followed immediately by a ')'.
5175 =item Sequence ?P=... not terminated in regex; marked by S<<-- HERE> in
5178 (F) A named reference of the form C<(?P=...)> was missing the final
5179 closing parenthesis after the name. The S<<-- HERE> shows whereabouts
5180 in the regular expression the problem was discovered.
5182 =item Sequence (?R) not terminated in regex m/%s/
5184 (F) An C<(?R)> or C<(?0)> sequence in a regular expression was missing the
5187 =item Server error (a.k.a. "500 Server error")
5189 (A) This is the error message generally seen in a browser window
5190 when trying to run a CGI program (including SSI) over the web. The
5191 actual error text varies widely from server to server. The most
5192 frequently-seen variants are "500 Server error", "Method (something)
5193 not permitted", "Document contains no data", "Premature end of script
5194 headers", and "Did not produce a valid header".
5196 B<This is a CGI error, not a Perl error>.
5198 You need to make sure your script is executable, is accessible by
5199 the user CGI is running the script under (which is probably not the
5200 user account you tested it under), does not rely on any environment
5201 variables (like PATH) from the user it isn't running under, and isn't
5202 in a location where the CGI server can't find it, basically, more or
5203 less. Please see the following for more information:
5205 http://www.perl.org/CGI_MetaFAQ.html
5206 http://www.htmlhelp.org/faq/cgifaq.html
5207 http://www.w3.org/Security/Faq/
5209 You should also look at L<perlfaq9>.
5211 =item setegid() not implemented
5213 (F) You tried to assign to C<$)>, and your operating system doesn't
5214 support the setegid() system call (or equivalent), or at least Configure
5217 =item seteuid() not implemented
5219 (F) You tried to assign to C<< $> >>, and your operating system doesn't
5220 support the seteuid() system call (or equivalent), or at least Configure
5223 =item setpgrp can't take arguments
5225 (F) Your system has the setpgrp() from BSD 4.2, which takes no
5226 arguments, unlike POSIX setpgid(), which takes a process ID and process
5229 =item setrgid() not implemented
5231 (F) You tried to assign to C<$(>, and your operating system doesn't
5232 support the setrgid() system call (or equivalent), or at least Configure
5235 =item setruid() not implemented
5237 (F) You tried to assign to C<$<>, and your operating system doesn't
5238 support the setruid() system call (or equivalent), or at least Configure
5241 =item setsockopt() on closed socket %s
5243 (W closed) You tried to set a socket option on a closed socket. Did you
5244 forget to check the return value of your socket() call? See
5245 L<perlfunc/setsockopt>.
5247 =item Setting ${^ENCODING} is deprecated
5249 (D deprecated) You assigned a non-C<undef> value to C<${^ENCODING}>.
5250 This is deprecated; see C<L<perlvar/${^ENCODING}>> for details.
5252 =item Setting $/ to a reference to %s as a form of slurp is deprecated, treating as undef
5254 (D deprecated) You assigned a reference to a scalar to C<$/> where the
5255 referenced item is not a positive integer. In older perls this B<appeared>
5256 to work the same as setting it to C<undef> but was in fact internally
5257 different, less efficient and with very bad luck could have resulted in
5258 your file being split by a stringified form of the reference.
5260 In Perl 5.20.0 this was changed so that it would be B<exactly> the same as
5261 setting C<$/> to undef, with the exception that this warning would be
5264 You are recommended to change your code to set C<$/> to C<undef> explicitly
5265 if you wish to slurp the file. In future versions of Perl assigning
5266 a reference to will throw a fatal error.
5268 =item Setting $/ to %s reference is forbidden
5270 (F) You tried to assign a reference to a non integer to C<$/>. In older
5271 Perls this would have behaved similarly to setting it to a reference to
5272 a positive integer, where the integer was the address of the reference.
5273 As of Perl 5.20.0 this is a fatal error, to allow future versions of Perl
5274 to use non-integer refs for more interesting purposes.
5276 =item shift on reference is experimental
5278 (S experimental::autoderef) C<shift> with a scalar argument is experimental
5279 and may change or be removed in a future Perl version. If you want to
5280 take the risk of using this feature, simply disable this warning:
5282 no warnings "experimental::autoderef";
5284 =item shm%s not implemented
5286 (F) You don't have System V shared memory IPC on your system.
5288 =item !=~ should be !~
5290 (W syntax) The non-matching operator is !~, not !=~. !=~ will be
5291 interpreted as the != (numeric not equal) and ~ (1's complement)
5292 operators: probably not what you intended.
5294 =item /%s/ should probably be written as "%s"
5296 (W syntax) You have used a pattern where Perl expected to find a string,
5297 as in the first argument to C<join>. Perl will treat the true or false
5298 result of matching the pattern against $_ as the string, which is
5299 probably not what you had in mind.
5301 =item shutdown() on closed socket %s
5303 (W closed) You tried to do a shutdown on a closed socket. Seems a bit
5306 =item SIG%s handler "%s" not defined
5308 (W signal) The signal handler named in %SIG doesn't, in fact, exist.
5309 Perhaps you put it into the wrong package?
5311 =item Slab leaked from cv %p
5313 (S) If you see this message, then something is seriously wrong with the
5314 internal bookkeeping of op trees. An op tree needed to be freed after
5315 a compilation error, but could not be found, so it was leaked instead.
5317 =item sleep(%u) too large
5319 (W overflow) You called C<sleep> with a number that was larger than
5320 it can reliably handle and C<sleep> probably slept for less time than
5323 =item Slurpy parameter not last
5325 (F) In a subroutine signature, you put something after a slurpy (array or
5326 hash) parameter. The slurpy parameter takes all the available arguments,
5327 so there can't be any left to fill later parameters.
5329 =item Smart matching a non-overloaded object breaks encapsulation
5331 (F) You should not use the C<~~> operator on an object that does not
5332 overload it: Perl refuses to use the object's underlying structure
5333 for the smart match.
5335 =item Smartmatch is experimental
5337 (S experimental::smartmatch) This warning is emitted if you
5338 use the smartmatch (C<~~>) operator. This is currently an experimental
5339 feature, and its details are subject to change in future releases of
5340 Perl. Particularly, its current behavior is noticed for being
5341 unnecessarily complex and unintuitive, and is very likely to be
5344 =item sort is now a reserved word
5346 (F) An ancient error message that almost nobody ever runs into anymore.
5347 But before sort was a keyword, people sometimes used it as a filehandle.
5349 =item Sort subroutine didn't return single value
5351 (F) A sort comparison subroutine written in XS must return exactly one
5352 item. See L<perlfunc/sort>.
5354 =item Source filters apply only to byte streams
5356 (F) You tried to activate a source filter (usually by loading a
5357 source filter module) within a string passed to C<eval>. This is
5358 not permitted under the C<unicode_eval> feature. Consider using
5359 C<evalbytes> instead. See L<feature>.
5361 =item splice() offset past end of array
5363 (W misc) You attempted to specify an offset that was past the end of
5364 the array passed to splice(). Splicing will instead commence at the
5365 end of the array, rather than past it. If this isn't what you want,
5366 try explicitly pre-extending the array by assigning $#array = $offset.
5367 See L<perlfunc/splice>.
5369 =item splice on reference is experimental
5371 (S experimental::autoderef) C<splice> with a scalar argument
5372 is experimental and may change or be removed in a future
5373 Perl version. If you want to take the risk of using this
5374 feature, simply disable this warning:
5376 no warnings "experimental::autoderef";
5380 (P) The split was looping infinitely. (Obviously, a split shouldn't
5381 iterate more times than there are characters of input, which is what
5382 happened.) See L<perlfunc/split>.
5384 =item Statement unlikely to be reached
5386 (W exec) You did an exec() with some statement after it other than a
5387 die(). This is almost always an error, because exec() never returns
5388 unless there was a failure. You probably wanted to use system()
5389 instead, which does return. To suppress this warning, put the exec() in
5392 =item "state" subroutine %s can't be in a package
5394 (F) Lexically scoped subroutines aren't in a package, so it doesn't make
5395 sense to try to declare one with a package qualifier on the front.
5397 =item "state %s" used in sort comparison
5399 (W syntax) The package variables $a and $b are used for sort comparisons.
5400 You used $a or $b in as an operand to the C<< <=> >> or C<cmp> operator inside a
5401 sort comparison block, and the variable had earlier been declared as a
5402 lexical variable. Either qualify the sort variable with the package
5403 name, or rename the lexical variable.
5405 =item "state" variable %s can't be in a package
5407 (F) Lexically scoped variables aren't in a package, so it doesn't make
5408 sense to try to declare one with a package qualifier on the front. Use
5409 local() if you want to localize a package variable.
5411 =item stat() on unopened filehandle %s
5413 (W unopened) You tried to use the stat() function on a filehandle that
5414 was either never opened or has since been closed.
5416 =item Strings with code points over 0xFF may not be mapped into in-memory file handles
5418 (W utf8) You tried to open a reference to a scalar for read or append
5419 where the scalar contained code points over 0xFF. In-memory files
5420 model on-disk files and can only contain bytes.
5422 =item Stub found while resolving method "%s" overloading "%s" in package "%s"
5424 (P) Overloading resolution over @ISA tree may be broken by importation
5425 stubs. Stubs should never be implicitly created, but explicit calls to
5426 C<can> may break this.
5428 =item Subroutine "&%s" is not available
5430 (W closure) During compilation, an inner named subroutine or eval is
5431 attempting to capture an outer lexical subroutine that is not currently
5432 available. This can happen for one of two reasons. First, the lexical
5433 subroutine may be declared in an outer anonymous subroutine that has
5434 not yet been created. (Remember that named subs are created at compile
5435 time, while anonymous subs are created at run-time.) For example,
5437 sub { my sub a {...} sub f { \&a } }
5439 At the time that f is created, it can't capture the current "a" sub,
5440 since the anonymous subroutine hasn't been created yet. Conversely, the
5441 following won't give a warning since the anonymous subroutine has by now
5442 been created and is live:
5444 sub { my sub a {...} eval 'sub f { \&a }' }->();
5446 The second situation is caused by an eval accessing a lexical subroutine
5447 that has gone out of scope, for example,
5455 Here, when the '\&a' in the eval is being compiled, f() is not currently
5456 being executed, so its &a is not available for capture.
5458 =item "%s" subroutine &%s masks earlier declaration in same %s
5460 (W misc) A "my" or "state" subroutine has been redeclared in the
5461 current scope or statement, effectively eliminating all access to
5462 the previous instance. This is almost always a typographical error.
5463 Note that the earlier subroutine will still exist until the end of
5464 the scope or until all closure references to it are destroyed.
5466 =item Subroutine %s redefined
5468 (W redefine) You redefined a subroutine. To suppress this warning, say
5471 no warnings 'redefine';
5472 eval "sub name { ... }";
5475 =item Subroutine "%s" will not stay shared
5477 (W closure) An inner (nested) I<named> subroutine is referencing a "my"
5478 subroutine defined in an outer named subroutine.
5480 When the inner subroutine is called, it will see the value of the outer
5481 subroutine's lexical subroutine as it was before and during the *first*
5482 call to the outer subroutine; in this case, after the first call to the
5483 outer subroutine is complete, the inner and outer subroutines will no
5484 longer share a common value for the lexical subroutine. In other words,
5485 it will no longer be shared. This will especially make a difference
5486 if the lexical subroutines accesses lexical variables declared in its
5489 This problem can usually be solved by making the inner subroutine
5490 anonymous, using the C<sub {}> syntax. When inner anonymous subs that
5491 reference lexical subroutines in outer subroutines are created, they
5492 are automatically rebound to the current values of such lexical subs.
5494 =item Substitution loop
5496 (P) The substitution was looping infinitely. (Obviously, a substitution
5497 shouldn't iterate more times than there are characters of input, which
5498 is what happened.) See the discussion of substitution in
5499 L<perlop/"Regexp Quote-Like Operators">.
5501 =item Substitution pattern not terminated
5503 (F) The lexer couldn't find the interior delimiter of an s/// or s{}{}
5504 construct. Remember that bracketing delimiters count nesting level.
5505 Missing the leading C<$> from variable C<$s> may cause this error.
5507 =item Substitution replacement not terminated
5509 (F) The lexer couldn't find the final delimiter of an s/// or s{}{}
5510 construct. Remember that bracketing delimiters count nesting level.
5511 Missing the leading C<$> from variable C<$s> may cause this error.
5513 =item substr outside of string
5515 (W substr)(F) You tried to reference a substr() that pointed outside of
5516 a string. That is, the absolute value of the offset was larger than the
5517 length of the string. See L<perlfunc/substr>. This warning is fatal if
5518 substr is used in an lvalue context (as the left hand side of an
5519 assignment or as a subroutine argument for example).
5521 =item sv_upgrade from type %d down to type %d
5523 (P) Perl tried to force the upgrade of an SV to a type which was actually
5524 inferior to its current type.
5526 =item SWASHNEW didn't return an HV ref
5528 (P) Something went wrong internally when Perl was trying to look up
5531 =item Switch (?(condition)... contains too many branches in regex; marked by
5532 S<<-- HERE> in m/%s/
5534 (F) A (?(condition)if-clause|else-clause) construct can have at most
5535 two branches (the if-clause and the else-clause). If you want one or
5536 both to contain alternation, such as using C<this|that|other>, enclose
5537 it in clustering parentheses:
5539 (?(condition)(?:this|that|other)|else-clause)
5541 The S<<-- HERE> shows whereabouts in the regular expression the problem
5542 was discovered. See L<perlre>.
5544 =item Switch condition not recognized in regex; marked by S<<-- HERE> in
5547 (F) The condition part of a (?(condition)if-clause|else-clause) construct
5548 is not known. The condition must be one of the following:
5550 (1) (2) ... true if 1st, 2nd, etc., capture matched
5551 (<NAME>) ('NAME') true if named capture matched
5552 (?=...) (?<=...) true if subpattern matches
5553 (?!...) (?<!...) true if subpattern fails to match
5554 (?{ CODE }) true if code returns a true value
5555 (R) true if evaluating inside recursion
5556 (R1) (R2) ... true if directly inside capture group 1, 2, etc.
5557 (R&NAME) true if directly inside named capture
5558 (DEFINE) always false; for defining named subpatterns
5560 The <-- HERE shows whereabouts in the regular expression the problem was
5561 discovered. See L<perlre>.
5563 =item Switch (?(condition)... not terminated in regex; marked by
5564 S<<-- HERE> in m/%s/
5566 (F) You omitted to close a (?(condition)...) block somewhere
5567 in the pattern. Add a closing parenthesis in the appropriate
5568 position. See L<perlre>.
5570 =item switching effective %s is not implemented
5572 (F) While under the C<use filetest> pragma, we cannot switch the real
5573 and effective uids or gids.
5577 (F) Probably means you had a syntax error. Common reasons include:
5579 A keyword is misspelled.
5580 A semicolon is missing.
5582 An opening or closing parenthesis is missing.
5583 An opening or closing brace is missing.
5584 A closing quote is missing.
5586 Often there will be another error message associated with the syntax
5587 error giving more information. (Sometimes it helps to turn on B<-w>.)
5588 The error message itself often tells you where it was in the line when
5589 it decided to give up. Sometimes the actual error is several tokens
5590 before this, because Perl is good at understanding random input.
5591 Occasionally the line number may be misleading, and once in a blue moon
5592 the only way to figure out what's triggering the error is to call
5593 C<perl -c> repeatedly, chopping away half the program each time to see
5594 if the error went away. Sort of the cybernetic version of S<20 questions>.
5596 =item syntax error at line %d: '%s' unexpected
5598 (A) You've accidentally run your script through the Bourne shell instead
5599 of Perl. Check the #! line, or manually feed your script into Perl
5602 =item syntax error in file %s at line %d, next 2 tokens "%s"
5604 (F) This error is likely to occur if you run a perl5 script through
5605 a perl4 interpreter, especially if the next 2 tokens are "use strict"
5606 or "my $var" or "our $var".
5608 =item Syntax error in (?[...]) in regex m/%s/
5610 (F) Perl could not figure out what you meant inside this construct; this
5611 notifies you that it is giving up trying.
5615 (F) The final summary message when a C<perl -c> succeeds.
5617 =item sysread() on closed filehandle %s
5619 (W closed) You tried to read from a closed filehandle.
5621 =item sysread() on unopened filehandle %s
5623 (W unopened) You tried to read from a filehandle that was never opened.
5625 =item System V %s is not implemented on this machine
5627 (F) You tried to do something with a function beginning with "sem",
5628 "shm", or "msg" but that System V IPC is not implemented in your
5629 machine. In some machines the functionality can exist but be
5630 unconfigured. Consult your system support.
5632 =item syswrite() on closed filehandle %s
5634 (W closed) The filehandle you're writing to got itself closed sometime
5635 before now. Check your control flow.
5637 =item C<-T> and C<-B> not implemented on filehandles
5639 (F) Perl can't peek at the stdio buffer of filehandles when it doesn't
5640 know about your kind of stdio. You'll have to use a filename instead.
5642 =item Target of goto is too deeply nested
5644 (F) You tried to use C<goto> to reach a label that was too deeply nested
5645 for Perl to reach. Perl is doing you a favor by refusing.
5647 =item telldir() attempted on invalid dirhandle %s
5649 (W io) The dirhandle you tried to telldir() is either closed or not really
5650 a dirhandle. Check your control flow.
5652 =item tell() on unopened filehandle
5654 (W unopened) You tried to use the tell() function on a filehandle that
5655 was either never opened or has since been closed.
5657 =item That use of $[ is unsupported
5659 (F) Assignment to C<$[> is now strictly circumscribed, and interpreted
5660 as a compiler directive. You may say only one of
5669 This is to prevent the problem of one module changing the array base out
5670 from under another module inadvertently. See L<perlvar/$[> and L<arybase>.
5672 =item The crypt() function is unimplemented due to excessive paranoia.
5674 (F) Configure couldn't find the crypt() function on your machine,
5675 probably because your vendor didn't supply it, probably because they
5676 think the U.S. Government thinks it's a secret, or at least that they
5677 will continue to pretend that it is. And if you quote me on that, I
5680 =item The %s function is unimplemented
5682 (F) The function indicated isn't implemented on this architecture,
5683 according to the probings of Configure.
5685 =item The lexical_subs feature is experimental
5687 (S experimental::lexical_subs) This warning is emitted if you
5688 declare a sub with C<my> or C<state>. Simply suppress the warning
5689 if you want to use the feature, but know that in doing so you
5690 are taking the risk of using an experimental feature which may
5691 change or be removed in a future Perl version:
5693 no warnings "experimental::lexical_subs";
5694 use feature "lexical_subs";
5697 =item The regex_sets feature is experimental
5699 (S experimental::regex_sets) This warning is emitted if you
5700 use the syntax S<C<(?[ ])>> in a regular expression.
5701 The details of this feature are subject to change.
5702 if you want to use it, but know that in doing so you
5703 are taking the risk of using an experimental feature which may
5704 change in a future Perl version, you can do this to silence the
5707 no warnings "experimental::regex_sets";
5709 =item The signatures feature is experimental
5711 (S experimental::signatures) This warning is emitted if you unwrap a
5712 subroutine's arguments using a signature. Simply suppress the warning
5713 if you want to use the feature, but know that in doing so you are taking
5714 the risk of using an experimental feature which may change or be removed
5715 in a future Perl version:
5717 no warnings "experimental::signatures";
5718 use feature "signatures";
5719 sub foo ($left, $right) { ... }
5721 =item The stat preceding %s wasn't an lstat
5723 (F) It makes no sense to test the current stat buffer for symbolic
5724 linkhood if the last stat that wrote to the stat buffer already went
5725 past the symlink to get to the real file. Use an actual filename
5728 =item The 'unique' attribute may only be applied to 'our' variables
5730 (F) This attribute was never supported on C<my> or C<sub> declarations.
5732 =item This Perl can't reset CRTL environ elements (%s)
5734 =item This Perl can't set CRTL environ elements (%s=%s)
5736 (W internal) Warnings peculiar to VMS. You tried to change or delete an
5737 element of the CRTL's internal environ array, but your copy of Perl
5738 wasn't built with a CRTL that contained the setenv() function. You'll
5739 need to rebuild Perl with a CRTL that does, or redefine
5740 F<PERL_ENV_TABLES> (see L<perlvms>) so that the environ array isn't the
5741 target of the change to
5742 %ENV which produced the warning.
5744 =item This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().
5746 (F) Something has attempted to use an internal API call which
5747 depends on Perl being compiled with the default support for randomized hash
5748 key traversal, but this Perl has been compiled without it. You should
5749 report this warning to the relevant upstream party, or recompile perl
5750 with default options.
5752 =item times not implemented
5754 (F) Your version of the C library apparently doesn't do times(). I
5755 suspect you're not running on Unix.
5757 =item "-T" is on the #! line, it must also be used on the command line
5759 (X) The #! line (or local equivalent) in a Perl script contains
5760 the B<-T> option (or the B<-t> option), but Perl was not invoked with
5761 B<-T> in its command line. This is an error because, by the time
5762 Perl discovers a B<-T> in a script, it's too late to properly taint
5763 everything from the environment. So Perl gives up.
5765 If the Perl script is being executed as a command using the #!
5766 mechanism (or its local equivalent), this error can usually be
5767 fixed by editing the #! line so that the B<-%c> option is a part of
5768 Perl's first argument: e.g. change C<perl -n -%c> to C<perl -%c -n>.
5770 If the Perl script is being executed as C<perl scriptname>, then the
5771 B<-%c> option must appear on the command line: C<perl -%c scriptname>.
5773 =item To%s: illegal mapping '%s'
5775 (F) You tried to define a customized To-mapping for lc(), lcfirst,
5776 uc(), or ucfirst() (or their string-inlined versions), but you
5777 specified an illegal mapping.
5778 See L<perlunicode/"User-Defined Character Properties">.
5780 =item Too deeply nested ()-groups
5782 (F) Your template contains ()-groups with a ridiculously deep nesting level.
5784 =item Too few args to syscall
5786 (F) There has to be at least one argument to syscall() to specify the
5787 system call to call, silly dilly.
5789 =item Too few arguments for subroutine
5791 (F) A subroutine using a signature received fewer arguments than required
5792 by the signature. The caller of the subroutine is presumably at fault.
5793 Inconveniently, this error will be reported at the location of the
5794 subroutine, not that of the caller.
5796 =item Too late for "-%s" option
5798 (X) The #! line (or local equivalent) in a Perl script contains the
5799 B<-M>, B<-m> or B<-C> option.
5801 In the case of B<-M> and B<-m>, this is an error because those options
5802 are not intended for use inside scripts. Use the C<use> pragma instead.
5804 The B<-C> option only works if it is specified on the command line as
5805 well (with the same sequence of letters or numbers following). Either
5806 specify this option on the command line, or, if your system supports
5807 it, make your script executable and run it directly instead of passing
5810 =item Too late to run %s block
5812 (W void) A CHECK or INIT block is being defined during run time proper,
5813 when the opportunity to run them has already passed. Perhaps you are
5814 loading a file with C<require> or C<do> when you should be using C<use>
5815 instead. Or perhaps you should put the C<require> or C<do> inside a
5818 =item Too many args to syscall
5820 (F) Perl supports a maximum of only 14 args to syscall().
5822 =item Too many arguments for %s
5824 (F) The function requires fewer arguments than you specified.
5826 =item Too many arguments for subroutine
5828 (F) A subroutine using a signature received more arguments than required
5829 by the signature. The caller of the subroutine is presumably at fault.
5830 Inconveniently, this error will be reported at the location of the
5831 subroutine, not that of the caller.
5835 (A) You've accidentally run your script through B<csh> instead of Perl.
5836 Check the #! line, or manually feed your script into Perl yourself.
5840 (A) You've accidentally run your script through B<csh> instead of Perl.
5841 Check the #! line, or manually feed your script into Perl yourself.
5843 =item Trailing \ in regex m/%s/
5845 (F) The regular expression ends with an unbackslashed backslash.
5846 Backslash it. See L<perlre>.
5848 =item Transliteration pattern not terminated
5850 (F) The lexer couldn't find the interior delimiter of a tr/// or tr[][]
5851 or y/// or y[][] construct. Missing the leading C<$> from variables
5852 C<$tr> or C<$y> may cause this error.
5854 =item Transliteration replacement not terminated
5856 (F) The lexer couldn't find the final delimiter of a tr///, tr[][],
5857 y/// or y[][] construct.
5859 =item '%s' trapped by operation mask
5861 (F) You tried to use an operator from a Safe compartment in which it's
5862 disallowed. See L<Safe>.
5864 =item truncate not implemented
5866 (F) Your machine doesn't implement a file truncation mechanism that
5867 Configure knows about.
5869 =item Type of arg %d to &CORE::%s must be %s
5871 (F) The subroutine in question in the CORE package requires its argument
5872 to be a hard reference to data of the specified type. Overloading is
5873 ignored, so a reference to an object that is not the specified type, but
5874 nonetheless has overloading to handle it, will still not be accepted.
5876 =item Type of arg %d to %s must be %s (not %s)
5878 (F) This function requires the argument in that position to be of a
5879 certain type. Arrays must be @NAME or C<@{EXPR}>. Hashes must be
5880 %NAME or C<%{EXPR}>. No implicit dereferencing is allowed--use the
5881 {EXPR} forms as an explicit dereference. See L<perlref>.
5883 =item Type of argument to %s must be unblessed hashref or arrayref
5885 (F) You called C<keys>, C<values> or C<each> with a scalar argument that
5886 was not a reference to an unblessed hash or array.
5888 =item umask not implemented
5890 (F) Your machine doesn't implement the umask function and you tried to
5891 use it to restrict permissions for yourself (EXPR & 0700).
5893 =item Unbalanced context: %d more PUSHes than POPs
5895 (S internal) The exit code detected an internal inconsistency in how
5896 many execution contexts were entered and left.
5898 =item Unbalanced saves: %d more saves than restores
5900 (S internal) The exit code detected an internal inconsistency in how
5901 many values were temporarily localized.
5903 =item Unbalanced scopes: %d more ENTERs than LEAVEs
5905 (S internal) The exit code detected an internal inconsistency in how
5906 many blocks were entered and left.
5908 =item Unbalanced string table refcount: (%d) for "%s"
5910 (S internal) On exit, Perl found some strings remaining in the shared
5911 string table used for copy on write and for hash keys. The entries
5912 should have been freed, so this indicates a bug somewhere.
5914 =item Unbalanced tmps: %d more allocs than frees
5916 (S internal) The exit code detected an internal inconsistency in how
5917 many mortal scalars were allocated and freed.
5919 =item Undefined format "%s" called
5921 (F) The format indicated doesn't seem to exist. Perhaps it's really in
5922 another package? See L<perlform>.
5924 =item Undefined sort subroutine "%s" called
5926 (F) The sort comparison routine specified doesn't seem to exist.
5927 Perhaps it's in a different package? See L<perlfunc/sort>.
5929 =item Undefined subroutine &%s called
5931 (F) The subroutine indicated hasn't been defined, or if it was, it has
5932 since been undefined.
5934 =item Undefined subroutine called
5936 (F) The anonymous subroutine you're trying to call hasn't been defined,
5937 or if it was, it has since been undefined.
5939 =item Undefined subroutine in sort
5941 (F) The sort comparison routine specified is declared but doesn't seem
5942 to have been defined yet. See L<perlfunc/sort>.
5944 =item Undefined top format "%s" called
5946 (F) The format indicated doesn't seem to exist. Perhaps it's really in
5947 another package? See L<perlform>.
5949 =item Undefined value assigned to typeglob
5951 (W misc) An undefined value was assigned to a typeglob, a la
5952 C<*foo = undef>. This does nothing. It's possible that you really mean
5955 =item %s: Undefined variable
5957 (A) You've accidentally run your script through B<csh> instead of Perl.
5958 Check the #! line, or manually feed your script into Perl yourself.
5960 =item Unescaped left brace in regex is deprecated, passed through in regex;
5961 marked by <-- HERE in m/%s/
5963 (D deprecated, regexp) You used a literal C<"{"> character in a regular
5964 expression pattern. You should change to use C<"\{"> instead, because a
5965 future version of Perl (tentatively v5.26) will consider this to be a
5966 syntax error. If the pattern delimiters are also braces, any matching
5967 right brace (C<"}">) should also be escaped to avoid confusing the parser,
5972 =item unexec of %s into %s failed!
5974 (F) The unexec() routine failed for some reason. See your local FSF
5975 representative, who probably put it there in the first place.
5977 =item Unexpected binary operator '%c' with no preceding operand in regex;
5978 marked by S<<-- HERE> in m/%s/
5980 (F) You had something like this:
5984 where the C<"|"> is a binary operator with an operand on the right, but
5985 no operand on the left.
5987 =item Unexpected character in regex; marked by S<<-- HERE> in m/%s/
5989 (F) You had something like this:
5993 Within C<(?[ ])>, no literal characters are allowed unless they are
5994 within an inner pair of square brackets, like
5998 Another possibility is that you forgot a backslash. Perl isn't smart
5999 enough to figure out what you really meant.
6001 =item Unexpected constant lvalue entersub entry via type/targ %d:%d
6003 (P) When compiling a subroutine call in lvalue context, Perl failed an
6004 internal consistency check. It encountered a malformed op tree.
6006 =item Unexpected exit %u
6008 (S) exit() was called or the script otherwise finished gracefully when
6009 C<PERL_EXIT_WARN> was set in C<PL_exit_flags>.
6011 =item Unexpected exit failure %d
6013 (S) An uncaught die() was called when C<PERL_EXIT_WARN> was set in
6016 =item Unexpected ')' in regex; marked by S<<-- HERE> in m/%s/
6018 (F) You had something like this:
6020 (?[ ( \p{Digit} + ) ])
6022 The C<")"> is out-of-place. Something apparently was supposed to
6023 be combined with the digits, or the C<"+"> shouldn't be there, or
6024 something like that. Perl can't figure out what was intended.
6026 =item Unexpected '(' with no preceding operator in regex; marked by
6027 S<<-- HERE> in m/%s/
6029 (F) You had something like this:
6031 (?[ \p{Digit} ( \p{Lao} + \p{Thai} ) ])
6033 There should be an operator before the C<"(">, as there's
6034 no indication as to how the digits are to be combined
6035 with the characters in the Lao and Thai scripts.
6037 =item Unicode non-character U+%X is illegal for open interchange
6039 (S nonchar) Certain codepoints, such as U+FFFE and U+FFFF, are
6040 defined by the Unicode standard to be non-characters. Those
6041 are legal codepoints, but are reserved for internal use; so,
6042 applications shouldn't attempt to exchange them. An application
6043 may not be expecting any of these characters at all, and receiving
6044 them may lead to bugs. If you know what you are doing you can
6045 turn off this warning by C<no warnings 'nonchar';>.
6047 This is not really a "severe" error, but it is supposed to be
6048 raised by default even if warnings are not enabled, and currently
6049 the only way to do that in Perl is to mark it as serious.
6051 =item Unicode surrogate U+%X is illegal in UTF-8
6053 (S surrogate) You had a UTF-16 surrogate in a context where they are
6054 not considered acceptable. These code points, between U+D800 and
6055 U+DFFF (inclusive), are used by Unicode only for UTF-16. However, Perl
6056 internally allows all unsigned integer code points (up to the size limit
6057 available on your platform), including surrogates. But these can cause
6058 problems when being input or output, which is likely where this message
6059 came from. If you really really know what you are doing you can turn
6060 off this warning by C<no warnings 'surrogate';>.
6062 =item Unknown charname '%s'
6064 (F) The name you used inside C<\N{}> is unknown to Perl. Check the
6065 spelling. You can say C<use charnames ":loose"> to not have to be
6066 so precise about spaces, hyphens, and capitalization on standard Unicode
6067 names. (Any custom aliases that have been created must be specified
6068 exactly, regardless of whether C<:loose> is used or not.) This error may
6069 also happen if the C<\N{}> is not in the scope of the corresponding
6070 C<S<use charnames>>.
6074 (P) Perl was about to print an error message in C<$@>, but the C<$@> variable
6075 did not exist, even after an attempt to create it.
6077 =item Unknown open() mode '%s'
6079 (F) The second argument of 3-argument open() is not among the list
6080 of valid modes: C<< < >>, C<< > >>, C<<< >> >>>, C<< +< >>,
6081 C<< +> >>, C<<< +>> >>>, C<-|>, C<|->, C<< <& >>, C<< >& >>.
6083 =item Unknown PerlIO layer "%s"
6085 (W layer) An attempt was made to push an unknown layer onto the Perl I/O
6086 system. (Layers take care of transforming data between external and
6087 internal representations.) Note that some layers, such as C<mmap>,
6088 are not supported in all environments. If your program didn't
6089 explicitly request the failing operation, it may be the result of the
6090 value of the environment variable PERLIO.
6092 =item Unknown process %x sent message to prime_env_iter: %s
6094 (P) An error peculiar to VMS. Perl was reading values for %ENV before
6095 iterating over it, and someone else stuck a message in the stream of
6096 data Perl expected. Someone's very confused, or perhaps trying to
6097 subvert Perl's population of %ENV for nefarious purposes.
6099 =item Unknown regex modifier "%s"
6101 (F) Alphanumerics immediately following the closing delimiter
6102 of a regular expression pattern are interpreted by Perl as modifier
6103 flags for the regex. One of the ones you specified is invalid. One way
6104 this can happen is if you didn't put in white space between the end of
6105 the regex and a following alphanumeric operator:
6107 if ($a =~ /foo/and $bar == 3) { ... }
6109 The C<"a"> is a valid modifier flag, but the C<"n"> is not, and raises
6110 this error. Likely what was meant instead was:
6112 if ($a =~ /foo/ and $bar == 3) { ... }
6114 =item Unknown "re" subpragma '%s' (known ones are: %s)
6116 (W) You tried to use an unknown subpragma of the "re" pragma.
6118 =item Unknown switch condition (?(...)) in regex; marked by S<<-- HERE> in
6121 (F) The condition part of a (?(condition)if-clause|else-clause) construct
6122 is not known. The condition must be one of the following:
6124 (1) (2) ... true if 1st, 2nd, etc., capture matched
6125 (<NAME>) ('NAME') true if named capture matched
6126 (?=...) (?<=...) true if subpattern matches
6127 (?!...) (?<!...) true if subpattern fails to match
6128 (?{ CODE }) true if code returns a true value
6129 (R) true if evaluating inside recursion
6130 (R1) (R2) ... true if directly inside capture group 1, 2, etc.
6131 (R&NAME) true if directly inside named capture
6132 (DEFINE) always false; for defining named subpatterns
6134 The <-- HERE shows whereabouts in the regular expression the problem was
6135 discovered. See L<perlre>.
6137 =item Unknown Unicode option letter '%c'
6139 (F) You specified an unknown Unicode option. See L<perlrun> documentation
6140 of the C<-C> switch for the list of known options.
6142 =item Unknown Unicode option value %d
6144 (F) You specified an unknown Unicode option. See L<perlrun> documentation
6145 of the C<-C> switch for the list of known options.
6147 =item Unknown verb pattern '%s' in regex; marked by S<<-- HERE> in m/%s/
6149 (F) You either made a typo or have incorrectly put a C<*> quantifier
6150 after an open brace in your pattern. Check the pattern and review
6151 L<perlre> for details on legal verb patterns.
6153 =item Unknown warnings category '%s'
6155 (F) An error issued by the C<warnings> pragma. You specified a warnings
6156 category that is unknown to perl at this point.
6158 Note that if you want to enable a warnings category registered by a
6159 module (e.g. C<use warnings 'File::Find'>), you must have loaded this
6162 =item Unmatched '[' in POSIX class in regex; marked by S<<-- HERE> in m/%s/
6164 (F) You had something like this:
6168 That should be written:
6172 =item Unmatched '%c' in POSIX class in regex; marked by S<<-- HERE> in
6175 (F) You had something like this:
6179 There should be a second C<":">, like this:
6183 =item Unmatched [ in regex; marked by S<<-- HERE> in m/%s/
6185 (F) The brackets around a character class must match. If you wish to
6186 include a closing bracket in a character class, backslash it or put it
6187 first. The S<<-- HERE> shows whereabouts in the regular expression the
6188 problem was discovered. See L<perlre>.
6190 =item Unmatched ( in regex; marked by S<<-- HERE> in m/%s/
6192 =item Unmatched ) in regex; marked by S<<-- HERE> in m/%s/
6194 (F) Unbackslashed parentheses must always be balanced in regular
6195 expressions. If you're a vi user, the % key is valuable for finding
6196 the matching parenthesis. The S<<-- HERE> shows whereabouts in the
6197 regular expression the problem was discovered. See L<perlre>.
6199 =item Unmatched right %s bracket
6201 (F) The lexer counted more closing curly or square brackets than opening
6202 ones, so you're probably missing a matching opening bracket. As a
6203 general rule, you'll find the missing one (so to speak) near the place
6204 you were last editing.
6206 =item Unquoted string "%s" may clash with future reserved word
6208 (W reserved) You used a bareword that might someday be claimed as a
6209 reserved word. It's best to put such a word in quotes, or capitalize it
6210 somehow, or insert an underbar into it. You might also declare it as a
6213 =item Unrecognized character %s; marked by S<<-- HERE> after %s near column
6216 (F) The Perl parser has no idea what to do with the specified character
6217 in your Perl script (or eval) near the specified column. Perhaps you
6218 tried to run a compressed script, a binary program, or a directory as
6221 =item Unrecognized escape \%c in character class in regex; marked by
6222 S<<-- HERE> in m/%s/
6224 (F) You used a backslash-character combination which is not
6225 recognized by Perl inside character classes. This is a fatal
6226 error when the character class is used within C<(?[ ])>.
6228 =item Unrecognized escape \%c in character class passed through in regex;
6229 marked by S<<-- HERE> in m/%s/
6231 (W regexp) You used a backslash-character combination which is not
6232 recognized by Perl inside character classes. The character was
6233 understood literally, but this may change in a future version of Perl.
6234 The S<<-- HERE> shows whereabouts in the regular expression the
6235 escape was discovered.
6237 =item Unrecognized escape \%c passed through
6239 (W misc) You used a backslash-character combination which is not
6240 recognized by Perl. The character was understood literally, but this may
6241 change in a future version of Perl.
6243 =item Unrecognized escape \%s passed through in regex; marked by
6244 S<<-- HERE> in m/%s/
6246 (W regexp) You used a backslash-character combination which is not
6247 recognized by Perl. The character(s) were understood literally, but
6248 this may change in a future version of Perl. The S<<-- HERE> shows
6249 whereabouts in the regular expression the escape was discovered.
6251 =item Unrecognized signal name "%s"
6253 (F) You specified a signal name to the kill() function that was not
6254 recognized. Say C<kill -l> in your shell to see the valid signal names
6257 =item Unrecognized switch: -%s (-h will show valid options)
6259 (F) You specified an illegal option to Perl. Don't do that. (If you
6260 think you didn't do that, check the #! line to see if it's supplying the
6261 bad switch on your behalf.)
6263 =item unshift on reference is experimental
6265 (S experimental::autoderef) C<unshift> with a scalar argument
6266 is experimental and may change or be removed in a future
6267 Perl version. If you want to take the risk of using this
6268 feature, simply disable this warning:
6270 no warnings "experimental::autoderef";
6272 =item Unsuccessful %s on filename containing newline
6274 (W newline) A file operation was attempted on a filename, and that
6275 operation failed, PROBABLY because the filename contained a newline,
6276 PROBABLY because you forgot to chomp() it off. See L<perlfunc/chomp>.
6278 =item Unsupported directory function "%s" called
6280 (F) Your machine doesn't support opendir() and readdir().
6282 =item Unsupported function %s
6284 (F) This machine doesn't implement the indicated function, apparently.
6285 At least, Configure doesn't think so.
6287 =item Unsupported function fork
6289 (F) Your version of executable does not support forking.
6291 Note that under some systems, like OS/2, there may be different flavors
6292 of Perl executables, some of which may support fork, some not. Try
6293 changing the name you call Perl by to C<perl_>, C<perl__>, and so on.
6295 =item Unsupported script encoding %s
6297 (F) Your program file begins with a Unicode Byte Order Mark (BOM) which
6298 declares it to be in a Unicode encoding that Perl cannot read.
6300 =item Unsupported socket function "%s" called
6302 (F) Your machine doesn't support the Berkeley socket mechanism, or at
6303 least that's what Configure thought.
6305 =item Unterminated attribute list
6307 (F) The lexer found something other than a simple identifier at the
6308 start of an attribute, and it wasn't a semicolon or the start of a
6309 block. Perhaps you terminated the parameter list of the previous
6310 attribute too soon. See L<attributes>.
6312 =item Unterminated attribute parameter in attribute list
6314 (F) The lexer saw an opening (left) parenthesis character while parsing
6315 an attribute list, but the matching closing (right) parenthesis
6316 character was not found. You may need to add (or remove) a backslash
6317 character to get your parentheses to balance. See L<attributes>.
6319 =item Unterminated compressed integer
6321 (F) An argument to unpack("w",...) was incompatible with the BER
6322 compressed integer format and could not be converted to an integer.
6323 See L<perlfunc/pack>.
6325 =item Unterminated delimiter for here document
6327 (F) This message occurs when a here document label has an initial
6328 quotation mark but the final quotation mark is missing. Perhaps
6337 =item Unterminated \g... pattern in regex; marked by S<<-- HERE> in m/%s/
6339 =item Unterminated \g{...} pattern in regex; marked by S<<-- HERE> in m/%s/
6341 (F) In a regular expression, you had a C<\g> that wasn't followed by a
6342 proper group reference. In the case of C<\g{>, the closing brace is
6343 missing; otherwise the C<\g> must be followed by an integer. Fix the
6346 =item Unterminated <> operator
6348 (F) The lexer saw a left angle bracket in a place where it was expecting
6349 a term, so it's looking for the corresponding right angle bracket, and
6350 not finding it. Chances are you left some needed parentheses out
6351 earlier in the line, and you really meant a "less than".
6353 =item Unterminated verb pattern argument in regex; marked by S<<-- HERE> in
6356 (F) You used a pattern of the form C<(*VERB:ARG)> but did not terminate
6357 the pattern with a C<)>. Fix the pattern and retry.
6359 =item Unterminated verb pattern in regex; marked by S<<-- HERE> in m/%s/
6361 (F) You used a pattern of the form C<(*VERB)> but did not terminate
6362 the pattern with a C<)>. Fix the pattern and retry.
6364 =item untie attempted while %d inner references still exist
6366 (W untie) A copy of the object returned from C<tie> (or C<tied>) was
6367 still valid when C<untie> was called.
6369 =item Usage: POSIX::%s(%s)
6371 (F) You called a POSIX function with incorrect arguments.
6372 See L<POSIX/FUNCTIONS> for more information.
6374 =item Usage: Win32::%s(%s)
6376 (F) You called a Win32 function with incorrect arguments.
6377 See L<Win32> for more information.
6379 =item $[ used in %s (did you mean $] ?)
6381 (W syntax) You used C<$[> in a comparison, such as:
6387 You probably meant to use C<$]> instead. C<$[> is the base for indexing
6388 arrays. C<$]> is the Perl version number in decimal.
6390 =item Use "%s" instead of "%s"
6392 (F) The second listed construct is no longer legal. Use the first one
6395 =item Useless assignment to a temporary
6397 (W misc) You assigned to an lvalue subroutine, but what
6398 the subroutine returned was a temporary scalar about to
6399 be discarded, so the assignment had no effect.
6401 =item Useless (?-%s) - don't use /%s modifier in regex; marked by
6402 S<<-- HERE> in m/%s/
6404 (W regexp) You have used an internal modifier such as (?-o) that has no
6405 meaning unless removed from the entire regexp:
6407 if ($string =~ /(?-o)$pattern/o) { ... }
6411 if ($string =~ /$pattern/) { ... }
6413 The <-- HERE shows whereabouts in the regular expression the problem was
6414 discovered. See L<perlre>.
6416 =item Useless localization of %s
6418 (W syntax) The localization of lvalues such as C<local($x=10)> is legal,
6419 but in fact the local() currently has no effect. This may change at
6420 some point in the future, but in the meantime such code is discouraged.
6422 =item Useless (?%s) - use /%s modifier in regex; marked by S<<-- HERE> in
6425 (W regexp) You have used an internal modifier such as (?o) that has no
6426 meaning unless applied to the entire regexp:
6428 if ($string =~ /(?o)$pattern/) { ... }
6432 if ($string =~ /$pattern/o) { ... }
6434 The <-- HERE shows whereabouts in the regular expression the problem was
6435 discovered. See L<perlre>.
6437 =item Useless use of /d modifier in transliteration operator
6439 (W misc) You have used the /d modifier where the searchlist has the
6440 same length as the replacelist. See L<perlop> for more information
6441 about the /d modifier.
6443 =item Useless use of \E
6445 (W misc) You have a \E in a double-quotish string without a C<\U>,
6446 C<\L> or C<\Q> preceding it.
6448 =item Useless use of greediness modifier '%c' in regex; marked by S<<-- HERE> in m/%s/
6450 (W regexp) You specified something like these:
6455 The C<"?"> and C<"+"> don't have any effect, as they modify whether to
6456 match more or fewer when there is a choice, and by specifying to match
6457 exactly a given numer, there is no room left for a choice.
6459 =item Useless use of %s in void context
6461 (W void) You did something without a side effect in a context that does
6462 nothing with the return value, such as a statement that doesn't return a
6463 value from a block, or the left side of a scalar comma operator. Very
6464 often this points not to stupidity on your part, but a failure of Perl
6465 to parse your program the way you thought it would. For example, you'd
6466 get this if you mixed up your C precedence with Python precedence and
6471 when you meant to say
6473 ($one, $two) = (1, 2);
6475 Another common error is to use ordinary parentheses to construct a list
6476 reference when you should be using square or curly brackets, for
6481 when you should have said
6485 The square brackets explicitly turn a list value into a scalar value,
6486 while parentheses do not. So when a parenthesized list is evaluated in
6487 a scalar context, the comma is treated like C's comma operator, which
6488 throws away the left argument, which is not what you want. See
6489 L<perlref> for more on this.
6491 This warning will not be issued for numerical constants equal to 0 or 1
6492 since they are often used in statements like
6494 1 while sub_with_side_effects();
6496 String constants that would normally evaluate to 0 or 1 are warned
6499 =item Unusual use of %s in void context
6501 (W void_unusual) Similar to the "Useless use of %s in void context"
6502 warning, but only turned on by the top-level "pedantic" warning
6503 category, used for e.g. C<grep> in void context, which may indicate a
6504 bug, but could also just be someone using C<grep> for its side-effects
6507 Enabled as part of "extra" warnings, not in the "all" category. See
6508 L<warnings> for details
6510 =item Useless use of (?-p) in regex; marked by S<<-- HERE> in m/%s/
6512 (W regexp) The C<p> modifier cannot be turned off once set. Trying to do
6515 =item Useless use of "re" pragma
6517 (W) You did C<use re;> without any arguments. That isn't very useful.
6519 =item Useless use of sort in scalar context
6521 (W void) You used sort in scalar context, as in :
6525 This is not very useful, and perl currently optimizes this away.
6527 =item Useless use of %s with no values
6529 (W syntax) You used the push() or unshift() function with no arguments
6530 apart from the array, like C<push(@x)> or C<unshift(@foo)>. That won't
6531 usually have any effect on the array, so is completely useless. It's
6532 possible in principle that push(@tied_array) could have some effect
6533 if the array is tied to a class which implements a PUSH method. If so,
6534 you can write it as C<push(@tied_array,())> to avoid this warning.
6536 =item "use" not allowed in expression
6538 (F) The "use" keyword is recognized and executed at compile time, and
6539 returns no useful value. See L<perlmod>.
6541 =item Use of assignment to $[ is deprecated
6543 (D deprecated) The C<$[> variable (index of the first element in an array)
6544 is deprecated. See L<perlvar/"$[">.
6546 =item Use of bare << to mean <<"" is deprecated
6548 (D deprecated) You are now encouraged to use the explicitly quoted
6549 form if you wish to use an empty line as the terminator of the
6552 =item Use of chdir('') or chdir(undef) as chdir() deprecated
6554 (D deprecated) chdir() with no arguments is documented to change to
6555 $ENV{HOME} or $ENV{LOGDIR}. chdir(undef) and chdir('') share this
6556 behavior, but that has been deprecated. In future versions they
6559 Be careful to check that what you pass to chdir() is defined and not
6560 blank, else you might find yourself in your home directory.
6562 =item Use of /c modifier is meaningless in s///
6564 (W regexp) You used the /c modifier in a substitution. The /c
6565 modifier is not presently meaningful in substitutions.
6567 =item Use of /c modifier is meaningless without /g
6569 (W regexp) You used the /c modifier with a regex operand, but didn't
6570 use the /g modifier. Currently, /c is meaningful only when /g is
6571 used. (This may change in the future.)
6573 =item Use of comma-less variable list is deprecated
6575 (D deprecated) The values you give to a format should be
6576 separated by commas, not just aligned on a line.
6578 =item Use of each() on hash after insertion without resetting hash iterator results in undefined behavior
6580 (S internal) The behavior of C<each()> after insertion is undefined;
6581 it may skip items, or visit items more than once. Consider using
6582 C<keys()> instead of C<each()>.
6584 =item Use of := for an empty attribute list is not allowed
6586 (F) The construction C<my $x := 42> used to parse as equivalent to
6587 C<my $x : = 42> (applying an empty attribute list to C<$x>).
6588 This construct was deprecated in 5.12.0, and has now been made a syntax
6589 error, so C<:=> can be reclaimed as a new operator in the future.
6591 If you need an empty attribute list, for example in a code generator, add
6592 a space before the C<=>.
6594 =item Use of freed value in iteration
6596 (F) Perhaps you modified the iterated array within the loop?
6597 This error is typically caused by code like the following:
6600 @a = () for (1,2,@a);
6602 You are not supposed to modify arrays while they are being iterated over.
6603 For speed and efficiency reasons, Perl internally does not do full
6604 reference-counting of iterated items, hence deleting such an item in the
6605 middle of an iteration causes Perl to see a freed value.
6607 =item Use of *glob{FILEHANDLE} is deprecated
6609 (D deprecated) You are now encouraged to use the shorter *glob{IO} form
6610 to access the filehandle slot within a typeglob.
6612 =item Use of /g modifier is meaningless in split
6614 (W regexp) You used the /g modifier on the pattern for a C<split>
6615 operator. Since C<split> always tries to match the pattern
6616 repeatedly, the C</g> has no effect.
6618 =item Use of "goto" to jump into a construct is deprecated
6620 (D deprecated) Using C<goto> to jump from an outer scope into an inner
6621 scope is deprecated and should be avoided.
6623 =item Use of inherited AUTOLOAD for non-method %s() is deprecated
6625 (D deprecated) As an (ahem) accidental feature, C<AUTOLOAD>
6626 subroutines are looked up as methods (using the C<@ISA> hierarchy)
6627 even when the subroutines to be autoloaded were called as plain
6628 functions (e.g. C<Foo::bar()>), not as methods (e.g. C<< Foo->bar() >> or
6629 C<< $obj->bar() >>).
6631 This bug will be rectified in future by using method lookup only for
6632 methods' C<AUTOLOAD>s. However, there is a significant base of existing
6633 code that may be using the old behavior. So, as an interim step, Perl
6634 currently issues an optional warning when non-methods use inherited
6637 The simple rule is: Inheritance will not work when autoloading
6638 non-methods. The simple fix for old code is: In any module that used
6639 to depend on inheriting C<AUTOLOAD> for non-methods from a base class
6640 named C<BaseClass>, execute C<*AUTOLOAD = \&BaseClass::AUTOLOAD> during
6643 In code that currently says C<use AutoLoader; @ISA = qw(AutoLoader);>
6644 you should remove AutoLoader from @ISA and change C<use AutoLoader;> to
6645 C<use AutoLoader 'AUTOLOAD';>.
6647 =item Use of %s in printf format not supported
6649 (F) You attempted to use a feature of printf that is accessible from
6650 only C. This usually means there's a better way to do it in Perl.
6652 =item Use of %s is deprecated
6654 (D deprecated) The construct indicated is no longer recommended for use,
6655 generally because there's a better way to do it, and also because the
6656 old way has bad side effects.
6658 =item Use of literal control characters in variable names is deprecated
6660 =item Use of literal non-graphic characters in variable names is deprecated
6662 (D deprecated) Using literal non-graphic (including control)
6663 characters in the source to refer to the ^FOO variables, like C<$^X> and
6664 C<${^GLOBAL_PHASE}> is now deprecated. (We use C<^X> and C<^G> here for
6665 legibility. They actually represent the non-printable control
6666 characters, code points 0x18 and 0x07, respectively; C<^A> would mean
6667 the control character whose code point is 0x01.) This only affects
6668 code like C<$\cT>, where C<\cT> is a control in the source code; C<${"\cT"}> and
6669 C<$^T> remain valid. Things that are non-controls and also not graphic
6670 are NO-BREAK SPACE and SOFT HYPHEN, which were previously only allowed
6671 for historical reasons.
6673 =item Use of -l on filehandle%s
6675 (W io) A filehandle represents an opened file, and when you opened the file
6676 it already went past any symlink you are presumably trying to look for.
6677 The operation returned C<undef>. Use a filename instead.
6679 =item Use of my $_ is experimental
6681 (S experimental::lexical_topic) Lexical $_ is an experimental feature and
6682 its behavior may change or even be removed in any future release of perl.
6683 See the explanation under L<perlvar/$_>.
6685 =item Use of %s on a handle without * is deprecated
6687 (D deprecated) You used C<tie>, C<tied> or C<untie> on a scalar but that scalar
6688 happens to hold a typeglob, which means its filehandle will be tied. If
6689 you mean to tie a handle, use an explicit * as in C<tie *$handle>.
6691 This was a long-standing bug that was removed in Perl 5.16, as there was
6692 no way to tie the scalar itself when it held a typeglob, and no way to
6693 untie a scalar that had had a typeglob assigned to it. If you see this
6694 message, you must be using an older version.
6696 =item Use of reference "%s" as array index
6698 (W misc) You tried to use a reference as an array index; this probably
6699 isn't what you mean, because references in numerical context tend
6700 to be huge numbers, and so usually indicates programmer error.
6702 If you really do mean it, explicitly numify your reference, like so:
6703 C<$array[0+$ref]>. This warning is not given for overloaded objects,
6704 however, because you can overload the numification and stringification
6705 operators and then you presumably know what you are doing.
6707 =item Use of state $_ is experimental
6709 (S experimental::lexical_topic) Lexical $_ is an experimental feature and
6710 its behavior may change or even be removed in any future release of perl.
6711 See the explanation under L<perlvar/$_>.
6713 =item Use of tainted arguments in %s is deprecated
6715 (W taint, deprecated) You have supplied C<system()> or C<exec()> with multiple
6716 arguments and at least one of them is tainted. This used to be allowed
6717 but will become a fatal error in a future version of perl. Untaint your
6718 arguments. See L<perlsec>.
6720 =item Use of uninitialized value%s
6722 (W uninitialized) An undefined value was used as if it were already
6723 defined. It was interpreted as a "" or a 0, but maybe it was a mistake.
6724 To suppress this warning assign a defined value to your variables.
6726 To help you figure out what was undefined, perl will try to tell you
6727 the name of the variable (if any) that was undefined. In some cases
6728 it cannot do this, so it also tells you what operation you used the
6729 undefined value in. Note, however, that perl optimizes your program
6730 and the operation displayed in the warning may not necessarily appear
6731 literally in your program. For example, C<"that $foo"> is usually
6732 optimized into C<"that " . $foo>, and the warning will refer to the
6733 C<concatenation (.)> operator, even though there is no C<.> in
6736 =item Use \x{...} for more than two hex characters in regex; marked by
6737 S<<-- HERE> in m/%s/
6739 (F) In a regular expression, you said something like
6743 Perl isn't sure if you meant this
6747 or if you meant this
6749 (?[ [ \x{BE} E F ] ])
6751 You need to add either braces or blanks to disambiguate.
6753 =item Using just the first character returned by \N{} in character class in
6754 regex; marked by S<<-- HERE> in m/%s/
6756 (W regexp) Named Unicode character escapes C<(\N{...})> may return
6757 a multi-character sequence. Even though a character class is
6758 supposed to match just one character of input, perl will match
6759 the whole thing correctly, except when the class is inverted
6760 (C<[^...]>), or the escape is the beginning or final end point of
6761 a range. For these, what should happen isn't clear at all. In
6762 these circumstances, Perl discards all but the first character
6763 of the returned sequence, which is not likely what you want.
6765 =item Using !~ with %s doesn't make sense
6767 (F) Using the C<!~> operator with C<s///r>, C<tr///r> or C<y///r> is
6768 currently reserved for future use, as the exact behavior has not
6769 been decided. (Simply returning the boolean opposite of the
6770 modified string is usually not particularly useful.)
6772 =item UTF-16 surrogate U+%X
6774 (S surrogate) You had a UTF-16 surrogate in a context where they are
6775 not considered acceptable. These code points, between U+D800 and
6776 U+DFFF (inclusive), are used by Unicode only for UTF-16. However, Perl
6777 internally allows all unsigned integer code points (up to the size limit
6778 available on your platform), including surrogates. But these can cause
6779 problems when being input or output, which is likely where this message
6780 came from. If you really really know what you are doing you can turn
6781 off this warning by C<no warnings 'surrogate';>.
6783 =item Value of %s can be "0"; test with defined()
6785 (W misc) In a conditional expression, you used <HANDLE>, <*> (glob),
6786 C<each()>, or C<readdir()> as a boolean value. Each of these constructs
6787 can return a value of "0"; that would make the conditional expression
6788 false, which is probably not what you intended. When using these
6789 constructs in conditional expressions, test their values with the
6790 C<defined> operator.
6792 =item Value of CLI symbol "%s" too long
6794 (W misc) A warning peculiar to VMS. Perl tried to read the value of an
6795 %ENV element from a CLI symbol table, and found a resultant string
6796 longer than 1024 characters. The return value has been truncated to
6799 =item values on reference is experimental
6801 (S experimental::autoderef) C<values> with a scalar argument
6802 is experimental and may change or be removed in a future
6803 Perl version. If you want to take the risk of using this
6804 feature, simply disable this warning:
6806 no warnings "experimental::autoderef";
6808 =item Variable "%s" is not available
6810 (W closure) During compilation, an inner named subroutine or eval is
6811 attempting to capture an outer lexical that is not currently available.
6812 This can happen for one of two reasons. First, the outer lexical may be
6813 declared in an outer anonymous subroutine that has not yet been created.
6814 (Remember that named subs are created at compile time, while anonymous
6815 subs are created at run-time.) For example,
6817 sub { my $a; sub f { $a } }
6819 At the time that f is created, it can't capture the current value of $a,
6820 since the anonymous subroutine hasn't been created yet. Conversely,
6821 the following won't give a warning since the anonymous subroutine has by
6822 now been created and is live:
6824 sub { my $a; eval 'sub f { $a }' }->();
6826 The second situation is caused by an eval accessing a variable that has
6827 gone out of scope, for example,
6835 Here, when the '$a' in the eval is being compiled, f() is not currently
6836 being executed, so its $a is not available for capture.
6838 =item Variable "%s" is not imported%s
6840 (S misc) With "use strict" in effect, you referred to a global variable
6841 that you apparently thought was imported from another module, because
6842 something else of the same name (usually a subroutine) is exported by
6843 that module. It usually means you put the wrong funny character on the
6844 front of your variable.
6846 =item Variable length lookbehind not implemented in regex m/%s/
6848 (F) Lookbehind is allowed only for subexpressions whose length is fixed and
6849 known at compile time. For positive lookbehind, you can use the C<\K>
6850 regex construct as a way to get the equivalent functionality. See
6851 L<perlre/(?<=pattern) \K>.
6853 There are non-obvious Unicode rules under C</i> that can match variably,
6854 but which you might not think could. For example, the substring C<"ss">
6855 can match the single character LATIN SMALL LETTER SHARP S. There are
6856 other sequences of ASCII characters that can match single ligature
6857 characters, such as LATIN SMALL LIGATURE FFI matching C<qr/ffi/i>.
6858 Starting in Perl v5.16, if you only care about ASCII matches, adding the
6859 C</aa> modifier to the regex will exclude all these non-obvious matches,
6860 thus getting rid of this message. You can also say C<S<use re qw(/aa)>>
6861 to apply C</aa> to all regular expressions compiled within its scope.
6864 =item "%s" variable %s masks earlier declaration in same %s
6866 (W misc) A "my", "our" or "state" variable has been redeclared in the
6867 current scope or statement, effectively eliminating all access to the
6868 previous instance. This is almost always a typographical error. Note
6869 that the earlier variable will still exist until the end of the scope
6870 or until all closure references to it are destroyed.
6872 =item Variable syntax
6874 (A) You've accidentally run your script through B<csh> instead
6875 of Perl. Check the #! line, or manually feed your script into
6878 =item Variable "%s" will not stay shared
6880 (W closure) An inner (nested) I<named> subroutine is referencing a
6881 lexical variable defined in an outer named subroutine.
6883 When the inner subroutine is called, it will see the value of
6884 the outer subroutine's variable as it was before and during the *first*
6885 call to the outer subroutine; in this case, after the first call to the
6886 outer subroutine is complete, the inner and outer subroutines will no
6887 longer share a common value for the variable. In other words, the
6888 variable will no longer be shared.
6890 This problem can usually be solved by making the inner subroutine
6891 anonymous, using the C<sub {}> syntax. When inner anonymous subs that
6892 reference variables in outer subroutines are created, they
6893 are automatically rebound to the current values of such variables.
6895 =item vector argument not supported with alpha versions
6897 (S printf) The %vd (s)printf format does not support version objects
6900 =item Verb pattern '%s' has a mandatory argument in regex; marked by
6901 S<<-- HERE> in m/%s/
6903 (F) You used a verb pattern that requires an argument. Supply an
6904 argument or check that you are using the right verb.
6906 =item Verb pattern '%s' may not have an argument in regex; marked by
6907 S<<-- HERE> in m/%s/
6909 (F) You used a verb pattern that is not allowed an argument. Remove the
6910 argument or check that you are using the right verb.
6912 =item Version number must be a constant number
6914 (P) The attempt to translate a C<use Module n.n LIST> statement into
6915 its equivalent C<BEGIN> block found an internal inconsistency with
6918 =item Version string '%s' contains invalid data; ignoring: '%s'
6920 (W misc) The version string contains invalid characters at the end, which
6923 =item Warning: something's wrong
6925 (W) You passed warn() an empty string (the equivalent of C<warn "">) or
6926 you called it with no args and C<$@> was empty.
6928 =item Warning: unable to close filehandle %s properly
6930 (S) The implicit close() done by an open() got an error indication on
6931 the close(). This usually indicates your file system ran out of disk
6934 =item Warning: unable to close filehandle properly: %s
6936 =item Warning: unable to close filehandle %s properly: %s
6938 (S io) An error occurred when Perl implicitly closed a filehandle. This
6939 usually indicates your file system ran out of disk space.
6941 =item Warning: Use of "%s" without parentheses is ambiguous
6943 (S ambiguous) You wrote a unary operator followed by something that
6944 looks like a binary operator that could also have been interpreted as a
6945 term or unary operator. For instance, if you know that the rand
6946 function has a default argument of 1.0, and you write
6950 you may THINK you wrote the same thing as
6954 but in actual fact, you got
6958 So put in parentheses to say what you really mean.
6960 =item when is experimental
6962 (S experimental::smartmatch) C<when> depends on smartmatch, which is
6963 experimental. Additionally, it has several special cases that may
6964 not be immediately obvious, and their behavior may change or
6965 even be removed in any future release of perl. See the explanation
6966 under L<perlsyn/Experimental Details on given and when>.
6968 =item Wide character in %s
6970 (S utf8) Perl met a wide character (>255) when it wasn't expecting
6971 one. This warning is by default on for I/O (like print). The easiest
6972 way to quiet this warning is simply to add the C<:utf8> layer to the
6973 output, e.g. C<binmode STDOUT, ':utf8'>. Another way to turn off the
6974 warning is to add C<no warnings 'utf8';> but that is often closer to
6975 cheating. In general, you are supposed to explicitly mark the
6976 filehandle with an encoding, see L<open> and L<perlfunc/binmode>.
6978 =item Wide character (U+%X) in %s
6980 (W locale) While in a single-byte locale (I<i.e.>, a non-UTF-8
6981 one), a multi-byte character was encountered. Perl considers this
6982 character to be the specified Unicode code point. Combining non-UTF8
6983 locales and Unicode is dangerous. Almost certainly some characters
6984 will have two different representations. For example, in the ISO 8859-7
6985 (Greek) locale, the code point 0xC3 represents a Capital Gamma. But so
6986 also does 0x393. This will make string comparisons unreliable.
6988 You likely need to figure out how this multi-byte character got mixed up
6989 with your single-byte locale (or perhaps you thought you had a UTF-8
6990 locale, but Perl disagrees).
6992 =item Within []-length '%c' not allowed
6994 (F) The count in the (un)pack template may be replaced by C<[TEMPLATE]>
6995 only if C<TEMPLATE> always matches the same amount of packed bytes that
6996 can be determined from the template alone. This is not possible if
6997 it contains any of the codes @, /, U, u, w or a *-length. Redesign
7000 =item write() on closed filehandle %s
7002 (W closed) The filehandle you're writing to got itself closed sometime
7003 before now. Check your control flow.
7005 =item %s "\x%X" does not map to Unicode
7007 (S utf8) When reading in different encodings, Perl tries to
7008 map everything into Unicode characters. The bytes you read
7009 in are not legal in this encoding. For example
7011 utf8 "\xE4" does not map to Unicode
7013 if you try to read in the a-diaereses Latin-1 as UTF-8.
7015 =item 'X' outside of string
7017 (F) You had a (un)pack template that specified a relative position before
7018 the beginning of the string being (un)packed. See L<perlfunc/pack>.
7020 =item 'x' outside of string in unpack
7022 (F) You had a pack template that specified a relative position after
7023 the end of the string being unpacked. See L<perlfunc/pack>.
7025 =item YOU HAVEN'T DISABLED SET-ID SCRIPTS IN THE KERNEL YET!
7027 (F) And you probably never will, because you probably don't have the
7028 sources to your kernel, and your vendor probably doesn't give a rip
7029 about what you want. Your best bet is to put a setuid C wrapper around
7032 =item You need to quote "%s"
7034 (W syntax) You assigned a bareword as a signal handler name.
7035 Unfortunately, you already have a subroutine of that name declared,
7036 which means that Perl 5 will try to call the subroutine when the
7037 assignment is executed, which is probably not what you want. (If it IS
7038 what you want, put an & in front.)
7040 =item Your random numbers are not that random
7042 (F) When trying to initialize the random seed for hashes, Perl could
7043 not get any randomness out of your system. This usually indicates
7044 Something Very Wrong.
7046 =item Zero length \N{} in regex; marked by S<<-- HERE> in m/%s/
7048 (F) Named Unicode character escapes (C<\N{...}>) may return a zero-length
7049 sequence. Such an escape was used in an extended character class, i.e.
7050 C<(?[...])>, which is not permitted. Check that the correct escape has
7051 been used, and the correct charnames handler is in scope. The S<<-- HERE>
7052 shows whereabouts in the regular expression the problem was discovered.
7058 L<warnings>, L<diagnostics>.