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 Note that for the C<Inf> and C<NaN> (infinity and not-a-number) the
193 definition of "numeric" is somewhat unusual: the strings themselves
194 (like "Inf") are considered numeric, and anything following them is
195 considered non-numeric.
197 =item Argument list not closed for PerlIO layer "%s"
199 (W layer) When pushing a layer with arguments onto the Perl I/O
200 system you forgot the ) that closes the argument list. (Layers
201 take care of transforming data between external and internal
202 representations.) Perl stopped parsing the layer list at this
203 point and did not attempt to push this layer. If your program
204 didn't explicitly request the failing operation, it may be the
205 result of the value of the environment variable PERLIO.
207 =item Argument "%s" treated as 0 in increment (++)
209 (W numeric) The indicated string was fed as an argument to the C<++>
210 operator which expects either a number or a string matching
211 C</^[a-zA-Z]*[0-9]*\z/>. See L<perlop/Auto-increment and
212 Auto-decrement> for details.
214 =item assertion botched: %s
216 (X) The malloc package that comes with Perl had an internal failure.
218 =item Assertion %s failed: file "%s", line %d
220 (X) A general assertion failed. The file in question must be examined.
222 =item Assigned value is not a reference
224 (F) You tried to assign something that was not a reference to an lvalue
225 reference (e.g., C<\$x = $y>). If you meant to make $x an alias to $y, use
228 =item Assigned value is not %s reference
230 (F) You tried to assign a reference to a reference constructor, but the
231 two references were not of the same type. You cannot alias a scalar to
232 an array, or an array to a hash; the two types must match.
237 \$x = $y; # error; did you mean \$y?
239 =item Assigning non-zero to $[ is no longer possible
241 (F) When the "array_base" feature is disabled (e.g., under C<use v5.16;>)
242 the special variable C<$[>, which is deprecated, is now a fixed zero value.
244 =item Assignment to both a list and a scalar
246 (F) If you assign to a conditional operator, the 2nd and 3rd arguments
247 must either both be scalars or both be lists. Otherwise Perl won't
248 know which context to supply to the right side.
250 =item <> at require-statement should be quotes
252 (F) You wrote C<< require <file> >> when you should have written
255 =item Attempt to access disallowed key '%s' in a restricted hash
257 (F) The failing code has attempted to get or set a key which is not in
258 the current set of allowed keys of a restricted hash.
260 =item Attempt to bless into a freed package
262 (F) You wrote C<bless $foo> with one argument after somehow causing
263 the current package to be freed. Perl cannot figure out what to
264 do, so it throws up in hands in despair.
266 =item Attempt to bless into a reference
268 (F) The CLASSNAME argument to the bless() operator is expected to be
269 the name of the package to bless the resulting object into. You've
270 supplied instead a reference to something: perhaps you wrote
276 bless $self, ref($proto) || $proto;
278 If you actually want to bless into the stringified version
279 of the reference supplied, you need to stringify it yourself, for
282 bless $self, "$proto";
284 =item Attempt to clear deleted array
286 (S debugging) An array was assigned to when it was being freed.
287 Freed values are not supposed to be visible to Perl code. This
288 can also happen if XS code calls C<av_clear> from a custom magic
289 callback on the array.
291 =item Attempt to delete disallowed key '%s' from a restricted hash
293 (F) The failing code attempted to delete from a restricted hash a key
294 which is not in its key set.
296 =item Attempt to delete readonly key '%s' from a restricted hash
298 (F) The failing code attempted to delete a key whose value has been
299 declared readonly from a restricted hash.
301 =item Attempt to free non-arena SV: 0x%x
303 (S internal) All SV objects are supposed to be allocated from arenas
304 that will be garbage collected on exit. An SV was discovered to be
305 outside any of those arenas.
307 =item Attempt to free nonexistent shared string '%s'%s
309 (S internal) Perl maintains a reference-counted internal table of
310 strings to optimize the storage and access of hash keys and other
311 strings. This indicates someone tried to decrement the reference count
312 of a string that can no longer be found in the table.
314 =item Attempt to free temp prematurely: SV 0x%x
316 (S debugging) Mortalized values are supposed to be freed by the
317 free_tmps() routine. This indicates that something else is freeing the
318 SV before the free_tmps() routine gets a chance, which means that the
319 free_tmps() routine will be freeing an unreferenced scalar when it does
322 =item Attempt to free unreferenced glob pointers
324 (S internal) The reference counts got screwed up on symbol aliases.
326 =item Attempt to free unreferenced scalar: SV 0x%x
328 (S internal) Perl went to decrement the reference count of a scalar to
329 see if it would go to 0, and discovered that it had already gone to 0
330 earlier, and should have been freed, and in fact, probably was freed.
331 This could indicate that SvREFCNT_dec() was called too many times, or
332 that SvREFCNT_inc() was called too few times, or that the SV was
333 mortalized when it shouldn't have been, or that memory has been
336 =item Attempt to pack pointer to temporary value
338 (W pack) You tried to pass a temporary value (like the result of a
339 function, or a computed expression) to the "p" pack() template. This
340 means the result contains a pointer to a location that could become
341 invalid anytime, even before the end of the current statement. Use
342 literals or global values as arguments to the "p" pack() template to
345 =item Attempt to reload %s aborted.
347 (F) You tried to load a file with C<use> or C<require> that failed to
348 compile once already. Perl will not try to compile this file again
349 unless you delete its entry from %INC. See L<perlfunc/require> and
352 =item Attempt to set length of freed array
354 (W misc) You tried to set the length of an array which has
355 been freed. You can do this by storing a reference to the
356 scalar representing the last index of an array and later
357 assigning through that reference. For example
359 $r = do {my @a; \$#a};
362 =item Attempt to use reference as lvalue in substr
364 (W substr) You supplied a reference as the first argument to substr()
365 used as an lvalue, which is pretty strange. Perhaps you forgot to
366 dereference it first. See L<perlfunc/substr>.
368 =item Attribute "locked" is deprecated
370 (D deprecated) You have used the attributes pragma to modify the
371 "locked" attribute on a code reference. The :locked attribute is
372 obsolete, has had no effect since 5005 threads were removed, and
373 will be removed in a future release of Perl 5.
375 =item Attribute prototype(%s) discards earlier prototype attribute in same sub
377 (W misc) A sub was declared as sub foo : prototype(A) : prototype(B) {}, for
378 example. Since each sub can only have one prototype, the earlier
379 declaration(s) are discarded while the last one is applied.
381 =item Attribute "unique" is deprecated
383 (D deprecated) You have used the attributes pragma to modify
384 the "unique" attribute on an array, hash or scalar reference.
385 The :unique attribute has had no effect since Perl 5.8.8, and
386 will be removed in a future release of Perl 5.
388 =item av_reify called on tied array
390 (S debugging) This indicates that something went wrong and Perl got I<very>
391 confused about C<@_> or C<@DB::args> being tied.
393 =item Bad arg length for %s, is %u, should be %d
395 (F) You passed a buffer of the wrong size to one of msgctl(), semctl()
396 or shmctl(). In C parlance, the correct sizes are, respectively,
397 S<sizeof(struct msqid_ds *)>, S<sizeof(struct semid_ds *)>, and
398 S<sizeof(struct shmid_ds *)>.
400 =item Bad evalled substitution pattern
402 (F) You've used the C</e> switch to evaluate the replacement for a
403 substitution, but perl found a syntax error in the code to evaluate,
404 most likely an unexpected right brace '}'.
406 =item Bad filehandle: %s
408 (F) A symbol was passed to something wanting a filehandle, but the
409 symbol has no filehandle associated with it. Perhaps you didn't do an
410 open(), or did it in another package.
412 =item Bad free() ignored
414 (S malloc) An internal routine called free() on something that had never
415 been malloc()ed in the first place. Mandatory, but can be disabled by
416 setting environment variable C<PERL_BADFREE> to 0.
418 This message can be seen quite often with DB_File on systems with "hard"
419 dynamic linking, like C<AIX> and C<OS/2>. It is a bug of C<Berkeley DB>
420 which is left unnoticed if C<DB> uses I<forgiving> system malloc().
424 (P) One of the internal hash routines was passed a null HV pointer.
426 =item Badly placed ()'s
428 (A) You've accidentally run your script through B<csh> instead
429 of Perl. Check the #! line, or manually feed your script into
432 =item Bad name after %s
434 (F) You started to name a symbol by using a package prefix, and then
435 didn't finish the symbol. In particular, you can't interpolate outside
444 $sym = "mypack::$var";
446 =item Bad plugin affecting keyword '%s'
448 (F) An extension using the keyword plugin mechanism violated the
451 =item Bad realloc() ignored
453 (S malloc) An internal routine called realloc() on something that
454 had never been malloc()ed in the first place. Mandatory, but can
455 be disabled by setting the environment variable C<PERL_BADFREE> to 1.
457 =item Bad symbol for array
459 (P) An internal request asked to add an array entry to something that
460 wasn't a symbol table entry.
462 =item Bad symbol for dirhandle
464 (P) An internal request asked to add a dirhandle entry to something
465 that wasn't a symbol table entry.
467 =item Bad symbol for filehandle
469 (P) An internal request asked to add a filehandle entry to something
470 that wasn't a symbol table entry.
472 =item Bad symbol for hash
474 (P) An internal request asked to add a hash entry to something that
475 wasn't a symbol table entry.
477 =item Bad symbol for scalar
479 (P) An internal request asked to add a scalar entry to something that
480 wasn't a symbol table entry.
482 =item Bareword found in conditional
484 (W bareword) The compiler found a bareword where it expected a
485 conditional, which often indicates that an || or && was parsed as part
486 of the last argument of the previous construct, for example:
490 It may also indicate a misspelled constant that has been interpreted as
493 use constant TYPO => 1;
494 if (TYOP) { print "foo" }
496 The C<strict> pragma is useful in avoiding such errors.
498 =item Bareword "%s" not allowed while "strict subs" in use
500 (F) With "strict subs" in use, a bareword is only allowed as a
501 subroutine identifier, in curly brackets or to the left of the "=>"
502 symbol. Perhaps you need to predeclare a subroutine?
504 =item Bareword "%s" refers to nonexistent package
506 (W bareword) You used a qualified bareword of the form C<Foo::>, but the
507 compiler saw no other uses of that namespace before that point. Perhaps
508 you need to predeclare a package?
510 =item BEGIN failed--compilation aborted
512 (F) An untrapped exception was raised while executing a BEGIN
513 subroutine. Compilation stops immediately and the interpreter is
516 =item BEGIN not safe after errors--compilation aborted
518 (F) Perl found a C<BEGIN {}> subroutine (or a C<use> directive, which
519 implies a C<BEGIN {}>) after one or more compilation errors had already
520 occurred. Since the intended environment for the C<BEGIN {}> could not
521 be guaranteed (due to the errors), and since subsequent code likely
522 depends on its correct operation, Perl just gave up.
524 =item \%d better written as $%d
526 (W syntax) Outside of patterns, backreferences live on as variables.
527 The use of backslashes is grandfathered on the right-hand side of a
528 substitution, but stylistically it's better to use the variable form
529 because other Perl programmers will expect it, and it works better if
530 there are more than 9 backreferences.
532 =item Binary number > 0b11111111111111111111111111111111 non-portable
534 (W portable) The binary number you specified is larger than 2**32-1
535 (4294967295) and therefore non-portable between systems. See
536 L<perlport> for more on portability concerns.
538 =item bind() on closed socket %s
540 (W closed) You tried to do a bind on a closed socket. Did you forget to
541 check the return value of your socket() call? See L<perlfunc/bind>.
543 =item binmode() on closed filehandle %s
545 (W unopened) You tried binmode() on a filehandle that was never opened.
546 Check your control flow and number of arguments.
548 =item Bit vector size > 32 non-portable
550 (W portable) Using bit vector sizes larger than 32 is non-portable.
552 =item Bizarre copy of %s
554 (P) Perl detected an attempt to copy an internal value that is not
557 =item Bizarre SvTYPE [%d]
559 (P) When starting a new thread or returning values from a thread, Perl
560 encountered an invalid data type.
562 =item Both or neither range ends should be Unicode in regex; marked by
565 (W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
567 In a bracketed character class in a regular expression pattern, you
568 had a range which has exactly one end of it specified using C<\N{}>, and
569 the other end is specified using a non-portable mechanism. Perl treats
570 the range as a Unicode range, that is, all the characters in it are
571 considered to be the Unicode characters, and which may be different code
572 points on some platforms Perl runs on. For example, C<[\N{U+06}-\x08]>
573 is treated as if you had instead said C<[\N{U+06}-\N{U+08}]>, that is it
574 matches the characters whose code points in Unicode are 6, 7, and 8.
575 But that C<\x08> might indicate that you meant something different, so
576 the warning gets raised.
578 =item Buffer overflow in prime_env_iter: %s
580 (W internal) A warning peculiar to VMS. While Perl was preparing to
581 iterate over %ENV, it encountered a logical name or symbol definition
582 which was too long, so it was truncated to the string shown.
584 =item Callback called exit
586 (F) A subroutine invoked from an external package via call_sv()
587 exited by calling exit.
589 =item %s() called too early to check prototype
591 (W prototype) You've called a function that has a prototype before the
592 parser saw a definition or declaration for it, and Perl could not check
593 that the call conforms to the prototype. You need to either add an
594 early prototype declaration for the subroutine in question, or move the
595 subroutine definition ahead of the call to get proper prototype
596 checking. Alternatively, if you are certain that you're calling the
597 function correctly, you may put an ampersand before the name to avoid
598 the warning. See L<perlsub>.
600 =item Calling POSIX::%s() is deprecated
602 (D deprecated) You called a function whose use is deprecated. See
603 the function's name in L<POSIX> for details.
607 (F) You passed an invalid number (like an infinity or not-a-number) to C<chr>.
609 =item Cannot compress %f in pack
611 (F) You tried compressing an infinity or not-a-number as an unsigned
612 integer with BER, which makes no sense.
614 =item Cannot compress integer in pack
616 (F) An argument to pack("w",...) was too large to compress.
617 The BER compressed integer format can only be used with positive
618 integers, and you attempted to compress a very large number (> 1e308).
619 See L<perlfunc/pack>.
621 =item Cannot compress negative numbers in pack
623 (F) An argument to pack("w",...) was negative. The BER compressed integer
624 format can only be used with positive integers. See L<perlfunc/pack>.
626 =item Cannot convert a reference to %s to typeglob
628 (F) You manipulated Perl's symbol table directly, stored a reference
629 in it, then tried to access that symbol via conventional Perl syntax.
630 The access triggers Perl to autovivify that typeglob, but it there is
631 no legal conversion from that type of reference to a typeglob.
633 =item Cannot copy to %s
635 (P) Perl detected an attempt to copy a value to an internal type that cannot
636 be directly assigned to.
638 =item Cannot find encoding "%s"
640 (S io) You tried to apply an encoding that did not exist to a filehandle,
641 either with open() or binmode().
643 =item Cannot pack %f with '%c'
645 (F) You tried converting an infinity or not-a-number to an integer,
646 which makes no sense.
648 =item Cannot printf %f with '%c'
650 (F) You tried printing an infinity or not-a-number as a character (%c),
651 which makes no sense. Maybe you meant '%s', or just stringifying it?
653 =item Cannot set tied @DB::args
655 (F) C<caller> tried to set C<@DB::args>, but found it tied. Tying C<@DB::args>
656 is not supported. (Before this error was added, it used to crash.)
658 =item Cannot tie unreifiable array
660 (P) You somehow managed to call C<tie> on an array that does not
661 keep a reference count on its arguments and cannot be made to
662 do so. Such arrays are not even supposed to be accessible to
663 Perl code, but are only used internally.
665 =item Can only compress unsigned integers in pack
667 (F) An argument to pack("w",...) was not an integer. The BER compressed
668 integer format can only be used with positive integers, and you attempted
669 to compress something else. See L<perlfunc/pack>.
671 =item Can't bless non-reference value
673 (F) Only hard references may be blessed. This is how Perl "enforces"
674 encapsulation of objects. See L<perlobj>.
676 =item Can't "break" in a loop topicalizer
678 (F) You called C<break>, but you're in a C<foreach> block rather than
679 a C<given> block. You probably meant to use C<next> or C<last>.
681 =item Can't "break" outside a given block
683 (F) You called C<break>, but you're not inside a C<given> block.
685 =item Can't call method "%s" on an undefined value
687 (F) You used the syntax of a method call, but the slot filled by the
688 object reference or package name contains an undefined value. Something
689 like this will reproduce the error:
692 process $BADREF 1,2,3;
693 $BADREF->process(1,2,3);
695 =item Can't call method "%s" on unblessed reference
697 (F) A method call must know in what package it's supposed to run. It
698 ordinarily finds this out from the object reference you supply, but you
699 didn't supply an object reference in this case. A reference isn't an
700 object reference until it has been blessed. See L<perlobj>.
702 =item Can't call method "%s" without a package or object reference
704 (F) You used the syntax of a method call, but the slot filled by the
705 object reference or package name contains an expression that returns a
706 defined value which is neither an object reference nor a package name.
707 Something like this will reproduce the error:
710 process $BADREF 1,2,3;
711 $BADREF->process(1,2,3);
713 =item Can't call mro_isa_changed_in() on anonymous symbol table
715 (P) Perl got confused as to whether a hash was a plain hash or a
716 symbol table hash when trying to update @ISA caches.
718 =item Can't call mro_method_changed_in() on anonymous symbol table
720 (F) An XS module tried to call C<mro_method_changed_in> on a hash that was
721 not attached to the symbol table.
723 =item Can't chdir to %s
725 (F) You called C<perl -x/foo/bar>, but F</foo/bar> is not a directory
726 that you can chdir to, possibly because it doesn't exist.
728 =item Can't check filesystem of script "%s" for nosuid
730 (P) For some reason you can't check the filesystem of the script for
733 =item Can't coerce %s to %s in %s
735 (F) Certain types of SVs, in particular real symbol table entries
736 (typeglobs), can't be forced to stop being what they are. So you can't
746 but then $foo no longer contains a glob.
748 =item Can't "continue" outside a when block
750 (F) You called C<continue>, but you're not inside a C<when>
753 =item Can't create pipe mailbox
755 (P) An error peculiar to VMS. The process is suffering from exhausted
756 quotas or other plumbing problems.
758 =item Can't declare %s in "%s"
760 (F) Only scalar, array, and hash variables may be declared as "my", "our" or
761 "state" variables. They must have ordinary identifiers as names.
763 =item Can't "default" outside a topicalizer
765 (F) You have used a C<default> block that is neither inside a
766 C<foreach> loop nor a C<given> block. (Note that this error is
767 issued on exit from the C<default> block, so you won't get the
768 error if you use an explicit C<continue>.)
770 =item Can't do inplace edit: %s is not a regular file
772 (S inplace) You tried to use the B<-i> switch on a special file, such as
773 a file in /dev, a FIFO or an uneditable directory. The file was ignored.
775 =item Can't do inplace edit on %s: %s
777 (S inplace) The creation of the new file failed for the indicated
780 =item Can't do inplace edit without backup
782 (F) You're on a system such as MS-DOS that gets confused if you try
783 reading from a deleted (but still opened) file. You have to say
784 C<-i.bak>, or some such.
786 =item Can't do inplace edit: %s would not be unique
788 (S inplace) Your filesystem does not support filenames longer than 14
789 characters and Perl was unable to create a unique filename during
790 inplace editing with the B<-i> switch. The file was ignored.
792 =item Can't do %s("%s") on non-UTF-8 locale; resolved to "%s".
794 (W locale) You are 1) running under "C<use locale>"; 2) the current
795 locale is not a UTF-8 one; 3) you tried to do the designated case-change
796 operation on the specified Unicode character; and 4) the result of this
797 operation would mix Unicode and locale rules, which likely conflict.
798 Mixing of different rule types is forbidden, so the operation was not
799 done; instead the result is the indicated value, which is the best
800 available that uses entirely Unicode rules. That turns out to almost
801 always be the original character, unchanged.
803 It is generally a bad idea to mix non-UTF-8 locales and Unicode, and
804 this issue is one of the reasons why. This warning is raised when
805 Unicode rules would normally cause the result of this operation to
806 contain a character that is in the range specified by the locale,
807 0..255, and hence is subject to the locale's rules, not Unicode's.
809 If you are using locale purely for its characteristics related to things
810 like its numeric and time formatting (and not C<LC_CTYPE>), consider
811 using a restricted form of the locale pragma (see L<perllocale/The "use
812 locale" pragma>) like "S<C<use locale ':not_characters'>>".
814 Note that failed case-changing operations done as a result of
815 case-insensitive C</i> regular expression matching will show up in this
816 warning as having the C<fc> operation (as that is what the regular
817 expression engine calls behind the scenes.)
819 =item Can't do waitpid with flags
821 (F) This machine doesn't have either waitpid() or wait4(), so only
822 waitpid() without flags is emulated.
824 =item Can't emulate -%s on #! line
826 (F) The #! line specifies a switch that doesn't make sense at this
827 point. For example, it'd be kind of silly to put a B<-x> on the #!
830 =item Can't %s %s-endian %ss on this platform
832 (F) Your platform's byte-order is neither big-endian nor little-endian,
833 or it has a very strange pointer size. Packing and unpacking big- or
834 little-endian floating point values and pointers may not be possible.
835 See L<perlfunc/pack>.
837 =item Can't exec "%s": %s
839 (W exec) A system(), exec(), or piped open call could not execute the
840 named program for the indicated reason. Typical reasons include: the
841 permissions were wrong on the file, the file wasn't found in
842 C<$ENV{PATH}>, the executable in question was compiled for another
843 architecture, or the #! line in a script points to an interpreter that
844 can't be run for similar reasons. (Or maybe your system doesn't support
849 (F) Perl was trying to execute the indicated program for you because
850 that's what the #! line said. If that's not what you wanted, you may
851 need to mention "perl" on the #! line somewhere.
853 =item Can't execute %s
855 (F) You used the B<-S> switch, but the copies of the script to execute
856 found in the PATH did not have correct permissions.
858 =item Can't find an opnumber for "%s"
860 (F) A string of a form C<CORE::word> was given to prototype(), but there
861 is no builtin with the name C<word>.
863 =item Can't find %s character property "%s"
865 (F) You used C<\p{}> or C<\P{}> but the character property by that name
866 could not be found. Maybe you misspelled the name of the property?
867 See L<perluniprops/Properties accessible through \p{} and \P{}>
868 for a complete list of available official properties.
870 =item Can't find label %s
872 (F) You said to goto a label that isn't mentioned anywhere that it's
873 possible for us to go to. See L<perlfunc/goto>.
875 =item Can't find %s on PATH
877 (F) You used the B<-S> switch, but the script to execute could not be
880 =item Can't find %s on PATH, '.' not in PATH
882 (F) You used the B<-S> switch, but the script to execute could not be
883 found in the PATH, or at least not with the correct permissions. The
884 script exists in the current directory, but PATH prohibits running it.
886 =item Can't find string terminator %s anywhere before EOF
888 (F) Perl strings can stretch over multiple lines. This message means
889 that the closing delimiter was omitted. Because bracketed quotes count
890 nesting levels, the following is missing its final parenthesis:
892 print q(The character '(' starts a side comment.);
894 If you're getting this error from a here-document, you may have
895 included unseen whitespace before or after your closing tag or there
896 may not be a linebreak after it. A good programmer's editor will have
897 a way to help you find these characters (or lack of characters). See
898 L<perlop> for the full details on here-documents.
900 =item Can't find Unicode property definition "%s"
902 (F) You may have tried to use C<\p> which means a Unicode
903 property (for example C<\p{Lu}> matches all uppercase
904 letters). If you did mean to use a Unicode property, see
905 L<perluniprops/Properties accessible through \p{} and \P{}>
906 for a complete list of available properties. If you didn't
907 mean to use a Unicode property, escape the C<\p>, either by
908 C<\\p> (just the C<\p>) or by C<\Q\p> (the rest of the string, or
913 (F) A fatal error occurred while trying to fork while opening a
916 =item Can't fork, trying again in 5 seconds
918 (W pipe) A fork in a piped open failed with EAGAIN and will be retried
921 =item Can't get filespec - stale stat buffer?
923 (S) A warning peculiar to VMS. This arises because of the difference
924 between access checks under VMS and under the Unix model Perl assumes.
925 Under VMS, access checks are done by filename, rather than by bits in
926 the stat buffer, so that ACLs and other protections can be taken into
927 account. Unfortunately, Perl assumes that the stat buffer contains all
928 the necessary information, and passes it, instead of the filespec, to
929 the access-checking routine. It will try to retrieve the filespec using
930 the device name and FID present in the stat buffer, but this works only
931 if you haven't made a subsequent call to the CRTL stat() routine,
932 because the device name is overwritten with each call. If this warning
933 appears, the name lookup failed, and the access-checking routine gave up
934 and returned FALSE, just to be conservative. (Note: The access-checking
935 routine knows about the Perl C<stat> operator and file tests, so you
936 shouldn't ever see this warning in response to a Perl command; it arises
937 only if some internal code takes stat buffers lightly.)
939 =item Can't get pipe mailbox device name
941 (P) An error peculiar to VMS. After creating a mailbox to act as a
942 pipe, Perl can't retrieve its name for later use.
944 =item Can't get SYSGEN parameter value for MAXBUF
946 (P) An error peculiar to VMS. Perl asked $GETSYI how big you want your
947 mailbox buffers to be, and didn't get an answer.
949 =item Can't "goto" into the middle of a foreach loop
951 (F) A "goto" statement was executed to jump into the middle of a foreach
952 loop. You can't get there from here. See L<perlfunc/goto>.
954 =item Can't "goto" out of a pseudo block
956 (F) A "goto" statement was executed to jump out of what might look like
957 a block, except that it isn't a proper block. This usually occurs if
958 you tried to jump out of a sort() block or subroutine, which is a no-no.
959 See L<perlfunc/goto>.
961 =item Can't goto subroutine from an eval-%s
963 (F) The "goto subroutine" call can't be used to jump out of an eval
966 =item Can't goto subroutine from a sort sub (or similar callback)
968 (F) The "goto subroutine" call can't be used to jump out of the
969 comparison sub for a sort(), or from a similar callback (such
970 as the reduce() function in List::Util).
972 =item Can't goto subroutine outside a subroutine
974 (F) The deeply magical "goto subroutine" call can only replace one
975 subroutine call for another. It can't manufacture one out of whole
976 cloth. In general you should be calling it out of only an AUTOLOAD
977 routine anyway. See L<perlfunc/goto>.
979 =item Can't ignore signal CHLD, forcing to default
981 (W signal) Perl has detected that it is being run with the SIGCHLD
982 signal (sometimes known as SIGCLD) disabled. Since disabling this
983 signal will interfere with proper determination of exit status of child
984 processes, Perl has reset the signal to its default value. This
985 situation typically indicates that the parent program under which Perl
986 may be running (e.g. cron) is being very careless.
988 =item Can't kill a non-numeric process ID
990 (F) Process identifiers must be (signed) integers. It is a fatal error to
991 attempt to kill() an undefined, empty-string or otherwise non-numeric
994 =item Can't "last" outside a loop block
996 (F) A "last" statement was executed to break out of the current block,
997 except that there's this itty bitty problem called there isn't a current
998 block. Note that an "if" or "else" block doesn't count as a "loopish"
999 block, as doesn't a block given to sort(), map() or grep(). You can
1000 usually double the curlies to get the same effect though, because the
1001 inner curlies will be considered a block that loops once. See
1004 =item Can't linearize anonymous symbol table
1006 (F) Perl tried to calculate the method resolution order (MRO) of a
1007 package, but failed because the package stash has no name.
1009 =item Can't load '%s' for module %s
1011 (F) The module you tried to load failed to load a dynamic extension.
1012 This may either mean that you upgraded your version of perl to one
1013 that is incompatible with your old dynamic extensions (which is known
1014 to happen between major versions of perl), or (more likely) that your
1015 dynamic extension was built against an older version of the library
1016 that is installed on your system. You may need to rebuild your old
1019 =item Can't localize lexical variable %s
1021 (F) You used local on a variable name that was previously declared as a
1022 lexical variable using "my" or "state". This is not allowed. If you
1023 want to localize a package variable of the same name, qualify it with
1026 =item Can't localize through a reference
1028 (F) You said something like C<local $$ref>, which Perl can't currently
1029 handle, because when it goes to restore the old value of whatever $ref
1030 pointed to after the scope of the local() is finished, it can't be sure
1031 that $ref will still be a reference.
1033 =item Can't locate %s
1035 (F) You said to C<do> (or C<require>, or C<use>) a file that couldn't be found.
1036 Perl looks for the file in all the locations mentioned in @INC, unless
1037 the file name included the full path to the file. Perhaps you need
1038 to set the PERL5LIB or PERL5OPT environment variable to say where the
1039 extra library is, or maybe the script needs to add the library name
1040 to @INC. Or maybe you just misspelled the name of the file. See
1041 L<perlfunc/require> and L<lib>.
1043 =item Can't locate auto/%s.al in @INC
1045 (F) A function (or method) was called in a package which allows
1046 autoload, but there is no function to autoload. Most probable causes
1047 are a misprint in a function/method name or a failure to C<AutoSplit>
1048 the file, say, by doing C<make install>.
1050 =item Can't locate loadable object for module %s in @INC
1052 (F) The module you loaded is trying to load an external library, like
1053 for example, F<foo.so> or F<bar.dll>, but the L<DynaLoader> module was
1054 unable to locate this library. See L<DynaLoader>.
1056 =item Can't locate object method "%s" via package "%s"
1058 (F) You called a method correctly, and it correctly indicated a package
1059 functioning as a class, but that package doesn't define that particular
1060 method, nor does any of its base classes. See L<perlobj>.
1062 =item Can't locate object method "%s" via package "%s" (perhaps you forgot
1065 (F) You called a method on a class that did not exist, and the method
1066 could not be found in UNIVERSAL. This often means that a method
1067 requires a package that has not been loaded.
1069 =item Can't locate package %s for @%s::ISA
1071 (W syntax) The @ISA array contained the name of another package that
1072 doesn't seem to exist.
1074 =item Can't locate PerlIO%s
1076 (F) You tried to use in open() a PerlIO layer that does not exist,
1077 e.g. open(FH, ">:nosuchlayer", "somefile").
1079 =item Can't make list assignment to %ENV on this system
1081 (F) List assignment to %ENV is not supported on some systems, notably
1084 =item Can't make loaded symbols global on this platform while loading %s
1086 (S) A module passed the flag 0x01 to DynaLoader::dl_load_file() to request
1087 that symbols from the stated file are made available globally within the
1088 process, but that functionality is not available on this platform. Whilst
1089 the module likely will still work, this may prevent the perl interpreter
1090 from loading other XS-based extensions which need to link directly to
1091 functions defined in the C or XS code in the stated file.
1093 =item Can't modify %s in %s
1095 (F) You aren't allowed to assign to the item indicated, or otherwise try
1096 to change it, such as with an auto-increment.
1098 =item Can't modify nonexistent substring
1100 (P) The internal routine that does assignment to a substr() was handed
1103 =item Can't modify non-lvalue subroutine call
1105 (F) Subroutines meant to be used in lvalue context should be declared as
1106 such. See L<perlsub/"Lvalue subroutines">.
1108 =item Can't modify reference to %s in %s assignment
1110 (F) Only a limited number of constructs can be used as the argument to a
1111 reference constructor on the left-hand side of an assignment, and what
1112 you used was not one of them. See L<perlref/Assigning to References>.
1114 =item Can't modify reference to localized parenthesized array in list
1117 (F) Assigning to C<\local(@array)> or C<\(local @array)> is not supported, as
1118 it is not clear exactly what it should do. If you meant to make @array
1119 refer to some other array, use C<\@array = \@other_array>. If you want to
1120 make the elements of @array aliases of the scalars referenced on the
1121 right-hand side, use C<\(@array) = @scalar_refs>.
1123 =item Can't modify reference to parenthesized hash in list assignment
1125 (F) Assigning to C<\(%hash)> is not supported. If you meant to make %hash
1126 refer to some other hash, use C<\%hash = \%other_hash>. If you want to
1127 make the elements of %hash into aliases of the scalars referenced on the
1128 right-hand side, use a hash slice: C<\@hash{@keys} = @those_scalar_refs>.
1130 =item Can't msgrcv to read-only var
1132 (F) The target of a msgrcv must be modifiable to be used as a receive
1135 =item Can't "next" outside a loop block
1137 (F) A "next" statement was executed to reiterate the current block, but
1138 there isn't a current block. Note that an "if" or "else" block doesn't
1139 count as a "loopish" block, as doesn't a block given to sort(), map() or
1140 grep(). You can usually double the curlies to get the same effect
1141 though, because the inner curlies will be considered a block that loops
1142 once. See L<perlfunc/next>.
1144 =item Can't open %s: %s
1146 (S inplace) The implicit opening of a file through use of the C<< <> >>
1147 filehandle, either implicitly under the C<-n> or C<-p> command-line
1148 switches, or explicitly, failed for the indicated reason. Usually
1149 this is because you don't have read permission for a file which
1150 you named on the command line.
1152 (F) You tried to call perl with the B<-e> switch, but F</dev/null> (or
1153 your operating system's equivalent) could not be opened.
1155 =item Can't open a reference
1157 (W io) You tried to open a scalar reference for reading or writing,
1158 using the 3-arg open() syntax:
1162 but your version of perl is compiled without perlio, and this form of
1163 open is not supported.
1165 =item Can't open bidirectional pipe
1167 (W pipe) You tried to say C<open(CMD, "|cmd|")>, which is not supported.
1168 You can try any of several modules in the Perl library to do this, such
1169 as IPC::Open2. Alternately, direct the pipe's output to a file using
1170 ">", and then read it in under a different file handle.
1172 =item Can't open error file %s as stderr
1174 (F) An error peculiar to VMS. Perl does its own command line
1175 redirection, and couldn't open the file specified after '2>' or '2>>' on
1176 the command line for writing.
1178 =item Can't open input file %s as stdin
1180 (F) An error peculiar to VMS. Perl does its own command line
1181 redirection, and couldn't open the file specified after '<' on the
1182 command line for reading.
1184 =item Can't open output file %s as stdout
1186 (F) An error peculiar to VMS. Perl does its own command line
1187 redirection, and couldn't open the file specified after '>' or '>>' on
1188 the command line for writing.
1190 =item Can't open output pipe (name: %s)
1192 (P) An error peculiar to VMS. Perl does its own command line
1193 redirection, and couldn't open the pipe into which to send data destined
1196 =item Can't open perl script "%s": %s
1198 (F) The script you specified can't be opened for the indicated reason.
1200 If you're debugging a script that uses #!, and normally relies on the
1201 shell's $PATH search, the -S option causes perl to do that search, so
1202 you don't have to type the path or C<`which $scriptname`>.
1204 =item Can't read CRTL environ
1206 (S) A warning peculiar to VMS. Perl tried to read an element of %ENV
1207 from the CRTL's internal environment array and discovered the array was
1208 missing. You need to figure out where your CRTL misplaced its environ
1209 or define F<PERL_ENV_TABLES> (see L<perlvms>) so that environ is not
1212 =item Can't "redo" outside a loop block
1214 (F) A "redo" statement was executed to restart the current block, but
1215 there isn't a current block. Note that an "if" or "else" block doesn't
1216 count as a "loopish" block, as doesn't a block given to sort(), map()
1217 or grep(). You can usually double the curlies to get the same effect
1218 though, because the inner curlies will be considered a block that
1219 loops once. See L<perlfunc/redo>.
1221 =item Can't remove %s: %s, skipping file
1223 (S inplace) You requested an inplace edit without creating a backup
1224 file. Perl was unable to remove the original file to replace it with
1225 the modified file. The file was left unmodified.
1227 =item Can't rename %s to %s: %s, skipping file
1229 (S inplace) The rename done by the B<-i> switch failed for some reason,
1230 probably because you don't have write permission to the directory.
1232 =item Can't reopen input pipe (name: %s) in binary mode
1234 (P) An error peculiar to VMS. Perl thought stdin was a pipe, and tried
1235 to reopen it to accept binary data. Alas, it failed.
1237 =item Can't represent character for Ox%X on this platform
1239 (F) There is a hard limit to how big a character code point can be due
1240 to the fundamental properties of UTF-8, especially on EBCDIC
1241 platforms. The given code point exceeds that. The only work-around is
1242 to not use such a large code point.
1244 =item Can't reset %ENV on this system
1246 (F) You called C<reset('E')> or similar, which tried to reset
1247 all variables in the current package beginning with "E". In
1248 the main package, that includes %ENV. Resetting %ENV is not
1249 supported on some systems, notably VMS.
1251 =item Can't resolve method "%s" overloading "%s" in package "%s"
1253 (F)(P) Error resolving overloading specified by a method name (as
1254 opposed to a subroutine reference): no such method callable via the
1255 package. If the method name is C<???>, this is an internal error.
1257 =item Can't return %s from lvalue subroutine
1259 (F) Perl detected an attempt to return illegal lvalues (such as
1260 temporary or readonly values) from a subroutine used as an lvalue. This
1263 =item Can't return outside a subroutine
1265 (F) The return statement was executed in mainline code, that is, where
1266 there was no subroutine call to return out of. See L<perlsub>.
1268 =item Can't return %s to lvalue scalar context
1270 (F) You tried to return a complete array or hash from an lvalue
1271 subroutine, but you called the subroutine in a way that made Perl
1272 think you meant to return only one value. You probably meant to
1273 write parentheses around the call to the subroutine, which tell
1274 Perl that the call should be in list context.
1276 =item Can't stat script "%s"
1278 (P) For some reason you can't fstat() the script even though you have it
1279 open already. Bizarre.
1281 =item Can't take log of %g
1283 (F) For ordinary real numbers, you can't take the logarithm of a
1284 negative number or zero. There's a Math::Complex package that comes
1285 standard with Perl, though, if you really want to do that for the
1288 =item Can't take sqrt of %g
1290 (F) For ordinary real numbers, you can't take the square root of a
1291 negative number. There's a Math::Complex package that comes standard
1292 with Perl, though, if you really want to do that.
1294 =item Can't undef active subroutine
1296 (F) You can't undefine a routine that's currently running. You can,
1297 however, redefine it while it's running, and you can even undef the
1298 redefined subroutine while the old routine is running. Go figure.
1300 =item Can't upgrade %s (%d) to %d
1302 (P) The internal sv_upgrade routine adds "members" to an SV, making it
1303 into a more specialized kind of SV. The top several SV types are so
1304 specialized, however, that they cannot be interconverted. This message
1305 indicates that such a conversion was attempted.
1307 =item Can't use '%c' after -mname
1309 (F) You tried to call perl with the B<-m> switch, but you put something
1310 other than "=" after the module name.
1312 =item Can't use a hash as a reference
1314 (F) You tried to use a hash as a reference, as in
1315 C<< %foo->{"bar"} >> or C<< %$ref->{"hello"} >>. Versions of perl
1316 <= 5.22.0 used to allow this syntax, but shouldn't
1317 have. This was deprecated in perl 5.6.1.
1319 =item Can't use an array as a reference
1321 (F) You tried to use an array as a reference, as in
1322 C<< @foo->[23] >> or C<< @$ref->[99] >>. Versions of perl <= 5.22.0
1323 used to allow this syntax, but shouldn't have. This
1324 was deprecated in perl 5.6.1.
1326 =item Can't use anonymous symbol table for method lookup
1328 (F) The internal routine that does method lookup was handed a symbol
1329 table that doesn't have a name. Symbol tables can become anonymous
1330 for example by undefining stashes: C<undef %Some::Package::>.
1332 =item Can't use an undefined value as %s reference
1334 (F) A value used as either a hard reference or a symbolic reference must
1335 be a defined value. This helps to delurk some insidious errors.
1337 =item Can't use bareword ("%s") as %s ref while "strict refs" in use
1339 (F) Only hard references are allowed by "strict refs". Symbolic
1340 references are disallowed. See L<perlref>.
1342 =item Can't use %! because Errno.pm is not available
1344 (F) The first time the C<%!> hash is used, perl automatically loads the
1345 Errno.pm module. The Errno module is expected to tie the %! hash to
1346 provide symbolic names for C<$!> errno values.
1348 =item Can't use both '<' and '>' after type '%c' in %s
1350 (F) A type cannot be forced to have both big-endian and little-endian
1351 byte-order at the same time, so this combination of modifiers is not
1352 allowed. See L<perlfunc/pack>.
1354 =item Can't use 'defined(@array)' (Maybe you should just omit the defined()?)
1356 (F) defined() is not useful on arrays because it
1357 checks for an undefined I<scalar> value. If you want to see if the
1358 array is empty, just use C<if (@array) { # not empty }> for example.
1360 =item Can't use 'defined(%hash)' (Maybe you should just omit the defined()?)
1362 (F) C<defined()> is not usually right on hashes.
1364 Although C<defined %hash> is false on a plain not-yet-used hash, it
1365 becomes true in several non-obvious circumstances, including iterators,
1366 weak references, stash names, even remaining true after C<undef %hash>.
1367 These things make C<defined %hash> fairly useless in practice, so it now
1368 generates a fatal error.
1370 If a check for non-empty is what you wanted then just put it in boolean
1371 context (see L<perldata/Scalar values>):
1377 If you had C<defined %Foo::Bar::QUUX> to check whether such a package
1378 variable exists then that's never really been reliable, and isn't
1379 a good way to enquire about the features of a package, or whether
1382 =item Can't use %s for loop variable
1384 (P) The parser got confused when trying to parse a C<foreach> loop.
1386 =item Can't use global %s in "%s"
1388 (F) You tried to declare a magical variable as a lexical variable. This
1389 is not allowed, because the magic can be tied to only one location
1390 (namely the global variable) and it would be incredibly confusing to
1391 have variables in your program that looked like magical variables but
1394 =item Can't use '%c' in a group with different byte-order in %s
1396 (F) You attempted to force a different byte-order on a type
1397 that is already inside a group with a byte-order modifier.
1398 For example you cannot force little-endianness on a type that
1399 is inside a big-endian group.
1401 =item Can't use "my %s" in sort comparison
1403 (F) The global variables $a and $b are reserved for sort comparisons.
1404 You mentioned $a or $b in the same line as the <=> or cmp operator,
1405 and the variable had earlier been declared as a lexical variable.
1406 Either qualify the sort variable with the package name, or rename the
1409 =item Can't use %s ref as %s ref
1411 (F) You've mixed up your reference types. You have to dereference a
1412 reference of the type needed. You can use the ref() function to
1413 test the type of the reference, if need be.
1415 =item Can't use string ("%s") as %s ref while "strict refs" in use
1417 =item Can't use string ("%s"...) as %s ref while "strict refs" in use
1419 (F) You've told Perl to dereference a string, something which
1420 C<use strict> blocks to prevent it happening accidentally. See
1421 L<perlref/"Symbolic references">. This can be triggered by an C<@> or C<$>
1422 in a double-quoted string immediately before interpolating a variable,
1423 for example in C<"user @$twitter_id">, which says to treat the contents
1424 of C<$twitter_id> as an array reference; use a C<\> to have a literal C<@>
1425 symbol followed by the contents of C<$twitter_id>: C<"user \@$twitter_id">.
1427 =item Can't use subscript on %s
1429 (F) The compiler tried to interpret a bracketed expression as a
1430 subscript. But to the left of the brackets was an expression that
1431 didn't look like a hash or array reference, or anything else subscriptable.
1433 =item Can't use \%c to mean $%c in expression
1435 (W syntax) In an ordinary expression, backslash is a unary operator that
1436 creates a reference to its argument. The use of backslash to indicate a
1437 backreference to a matched substring is valid only as part of a regular
1438 expression pattern. Trying to do this in ordinary Perl code produces a
1439 value that prints out looking like SCALAR(0xdecaf). Use the $1 form
1442 =item Can't weaken a nonreference
1444 (F) You attempted to weaken something that was not a reference. Only
1445 references can be weakened.
1447 =item Can't "when" outside a topicalizer
1449 (F) You have used a when() block that is neither inside a C<foreach>
1450 loop nor a C<given> block. (Note that this error is issued on exit
1451 from the C<when> block, so you won't get the error if the match fails,
1452 or if you use an explicit C<continue>.)
1454 =item Can't x= to read-only value
1456 (F) You tried to repeat a constant value (often the undefined value)
1457 with an assignment operator, which implies modifying the value itself.
1458 Perhaps you need to copy the value to a temporary, and repeat that.
1460 =item Character following "\c" must be printable ASCII
1462 (F) In C<\cI<X>>, I<X> must be a printable (non-control) ASCII character.
1464 Note that ASCII characters that don't map to control characters are
1465 discouraged, and will generate the warning (when enabled)
1466 L</""\c%c" is more clearly written simply as "%s"">.
1468 =item Character in 'C' format wrapped in pack
1474 where $x is either less than 0 or more than 255; the C<"C"> format is
1475 only for encoding native operating system characters (ASCII, EBCDIC,
1476 and so on) and not for Unicode characters, so Perl behaved as if you meant
1480 If you actually want to pack Unicode codepoints, use the C<"U"> format
1483 =item Character in 'c' format wrapped in pack
1489 where $x is either less than -128 or more than 127; the C<"c"> format
1490 is only for encoding native operating system characters (ASCII, EBCDIC,
1491 and so on) and not for Unicode characters, so Perl behaved as if you meant
1493 pack("c", $x & 255);
1495 If you actually want to pack Unicode codepoints, use the C<"U"> format
1498 =item Character in '%c' format wrapped in unpack
1500 (W unpack) You tried something like
1502 unpack("H", "\x{2a1}")
1504 where the format expects to process a byte (a character with a value
1505 below 256), but a higher value was provided instead. Perl uses the
1506 value modulus 256 instead, as if you had provided:
1508 unpack("H", "\x{a1}")
1510 =item Character in 'W' format wrapped in pack
1516 where $x is either less than 0 or more than 255. However, C<U0>-mode
1517 expects all values to fall in the interval [0, 255], so Perl behaved
1520 pack("U0W", $x & 255)
1522 =item Character(s) in '%c' format wrapped in pack
1524 (W pack) You tried something like
1526 pack("u", "\x{1f3}b")
1528 where the format expects to process a sequence of bytes (character with a
1529 value below 256), but some of the characters had a higher value. Perl
1530 uses the character values modulus 256 instead, as if you had provided:
1532 pack("u", "\x{f3}b")
1534 =item Character(s) in '%c' format wrapped in unpack
1536 (W unpack) You tried something like
1538 unpack("s", "\x{1f3}b")
1540 where the format expects to process a sequence of bytes (character with a
1541 value below 256), but some of the characters had a higher value. Perl
1542 uses the character values modulus 256 instead, as if you had provided:
1544 unpack("s", "\x{f3}b")
1546 =item charnames alias definitions may not contain a sequence of multiple spaces
1548 (F) You defined a character name which had multiple space characters
1549 in a row. Change them to single spaces. Usually these names are
1550 defined in the C<:alias> import argument to C<use charnames>, but they
1551 could be defined by a translator installed into C<$^H{charnames}>. See
1552 L<charnames/CUSTOM ALIASES>.
1554 =item charnames alias definitions may not contain trailing white-space
1556 (F) You defined a character name which ended in a space
1557 character. Remove the trailing space(s). Usually these names are
1558 defined in the C<:alias> import argument to C<use charnames>, but they
1559 could be defined by a translator installed into C<$^H{charnames}>.
1560 See L<charnames/CUSTOM ALIASES>.
1562 =item \C is deprecated in regex; marked by <-- HERE in m/%s/
1564 (D deprecated, regexp) The \C character class is deprecated, and will
1565 become a compile-time error in a future release of perl (tentatively
1566 v5.24). This construct allows you to match a single byte of what makes
1567 up a multi-byte single UTF8 character, and breaks encapsulation. It is
1568 currently also very buggy. If you really need to process the individual
1569 bytes, you probably want to convert your string to one where each
1570 underlying byte is stored as a character, with utf8::encode().
1572 =item "\c%c" is more clearly written simply as "%s"
1574 (W syntax) The C<\cI<X>> construct is intended to be a way to specify
1575 non-printable characters. You used it for a printable one, which
1576 is better written as simply itself, perhaps preceded by a backslash
1577 for non-word characters. Doing it the way you did is not portable
1578 between ASCII and EBCDIC platforms.
1580 =item Cloning substitution context is unimplemented
1582 (F) Creating a new thread inside the C<s///> operator is not supported.
1584 =item closedir() attempted on invalid dirhandle %s
1586 (W io) The dirhandle you tried to close is either closed or not really
1587 a dirhandle. Check your control flow.
1589 =item close() on unopened filehandle %s
1591 (W unopened) You tried to close a filehandle that was never opened.
1593 =item Closure prototype called
1595 (F) If a closure has attributes, the subroutine passed to an attribute
1596 handler is the prototype that is cloned when a new closure is created.
1597 This subroutine cannot be called.
1599 =item Code missing after '/'
1601 (F) You had a (sub-)template that ends with a '/'. There must be
1602 another template code following the slash. See L<perlfunc/pack>.
1604 =item Code point 0x%X is not Unicode, may not be portable
1606 (S non_unicode) You had a code point above the Unicode maximum
1609 Perl allows strings to contain a superset of Unicode code points, up
1610 to the limit of what is storable in an unsigned integer on your system,
1611 but these may not be accepted by other languages/systems. At one time,
1612 it was legal in some standards to have code points up to 0x7FFF_FFFF,
1613 but not higher. Code points above 0xFFFF_FFFF require larger than a
1616 =item %s: Command not found
1618 (A) You've accidentally run your script through B<csh> or another shell
1619 instead of Perl. Check the #! line, or manually feed your script into
1620 Perl yourself. The #! line at the top of your file could look like
1624 =item Compilation failed in require
1626 (F) Perl could not compile a file specified in a C<require> statement.
1627 Perl uses this generic message when none of the errors that it
1628 encountered were severe enough to halt compilation immediately.
1630 =item Complex regular subexpression recursion limit (%d) exceeded
1632 (W regexp) The regular expression engine uses recursion in complex
1633 situations where back-tracking is required. Recursion depth is limited
1634 to 32766, or perhaps less in architectures where the stack cannot grow
1635 arbitrarily. ("Simple" and "medium" situations are handled without
1636 recursion and are not subject to a limit.) Try shortening the string
1637 under examination; looping in Perl code (e.g. with C<while>) rather than
1638 in the regular expression engine; or rewriting the regular expression so
1639 that it is simpler or backtracks less. (See L<perlfaq2> for information
1640 on I<Mastering Regular Expressions>.)
1642 =item connect() on closed socket %s
1644 (W closed) You tried to do a connect on a closed socket. Did you forget
1645 to check the return value of your socket() call? See
1646 L<perlfunc/connect>.
1648 =item Constant(%s): Call to &{$^H{%s}} did not return a defined value
1650 (F) The subroutine registered to handle constant overloading
1651 (see L<overload>) or a custom charnames handler (see
1652 L<charnames/CUSTOM TRANSLATORS>) returned an undefined value.
1654 =item Constant(%s): $^H{%s} is not defined
1656 (F) The parser found inconsistencies while attempting to define an
1657 overloaded constant. Perhaps you forgot to load the corresponding
1660 =item Constant is not %s reference
1662 (F) A constant value (perhaps declared using the C<use constant> pragma)
1663 is being dereferenced, but it amounts to the wrong type of reference.
1664 The message indicates the type of reference that was expected. This
1665 usually indicates a syntax error in dereferencing the constant value.
1666 See L<perlsub/"Constant Functions"> and L<constant>.
1668 =item Constants from lexical variables potentially modified elsewhere are
1671 (D deprecated) You wrote something like
1674 $sub = sub () { $var };
1676 but $var is referenced elsewhere and could be modified after the C<sub>
1677 expression is evaluated. Either it is explicitly modified elsewhere
1678 (C<$var = 3>) or it is passed to a subroutine or to an operator like
1679 C<printf> or C<map>, which may or may not modify the variable.
1681 Traditionally, Perl has captured the value of the variable at that
1682 point and turned the subroutine into a constant eligible for inlining.
1683 In those cases where the variable can be modified elsewhere, this
1684 breaks the behavior of closures, in which the subroutine captures
1685 the variable itself, rather than its value, so future changes to the
1686 variable are reflected in the subroutine's return value.
1688 This usage is deprecated, because the behavior is likely to change
1689 in a future version of Perl.
1691 If you intended for the subroutine to be eligible for inlining, then
1692 make sure the variable is not referenced elsewhere, possibly by
1696 $sub = sub () { $var2 };
1698 If you do want this subroutine to be a closure that reflects future
1699 changes to the variable that it closes over, add an explicit C<return>:
1702 $sub = sub () { return $var };
1704 =item Constant subroutine %s redefined
1706 (W redefine)(S) You redefined a subroutine which had previously
1707 been eligible for inlining. See L<perlsub/"Constant Functions">
1708 for commentary and workarounds.
1710 =item Constant subroutine %s undefined
1712 (W misc) You undefined a subroutine which had previously been eligible
1713 for inlining. See L<perlsub/"Constant Functions"> for commentary and
1716 =item Constant(%s) unknown
1718 (F) The parser found inconsistencies either while attempting
1719 to define an overloaded constant, or when trying to find the
1720 character name specified in the C<\N{...}> escape. Perhaps you
1721 forgot to load the corresponding L<overload> pragma?.
1723 =item :const is experimental
1725 (S experimental::const_attr) The "const" attribute is experimental.
1726 If you want to use the feature, disable the warning with C<no warnings
1727 'experimental::const_attr'>, but know that in doing so you are taking
1728 the risk that your code may break in a future Perl version.
1730 =item :const is not permitted on named subroutines
1732 (F) The "const" attribute causes an anonymous subroutine to be run and
1733 its value captured at the time that it is cloned. Named subroutines are
1734 not cloned like this, so the attribute does not make sense on them.
1736 =item Copy method did not return a reference
1738 (F) The method which overloads "=" is buggy. See
1739 L<overload/Copy Constructor>.
1741 =item &CORE::%s cannot be called directly
1743 (F) You tried to call a subroutine in the C<CORE::> namespace
1744 with C<&foo> syntax or through a reference. Some subroutines
1745 in this package cannot yet be called that way, but must be
1746 called as barewords. Something like this will work:
1748 BEGIN { *shove = \&CORE::push; }
1749 shove @array, 1,2,3; # pushes on to @array
1751 =item CORE::%s is not a keyword
1753 (F) The CORE:: namespace is reserved for Perl keywords.
1755 =item Corrupted regexp opcode %d > %d
1757 (P) This is either an error in Perl, or, if you're using
1758 one, your L<custom regular expression engine|perlreapi>. If not the
1759 latter, report the problem through the L<perlbug> utility.
1761 =item corrupted regexp pointers
1763 (P) The regular expression engine got confused by what the regular
1764 expression compiler gave it.
1766 =item corrupted regexp program
1768 (P) The regular expression engine got passed a regexp program without a
1771 =item Corrupt malloc ptr 0x%x at 0x%x
1773 (P) The malloc package that comes with Perl had an internal failure.
1775 =item Count after length/code in unpack
1777 (F) You had an unpack template indicating a counted-length string, but
1778 you have also specified an explicit size for the string. See
1782 The following are used in lib/diagnostics.t for testing two =items that
1783 share the same description. Changes here need to be propagated to there
1785 =item Deep recursion on anonymous subroutine
1787 =item Deep recursion on subroutine "%s"
1789 (W recursion) This subroutine has called itself (directly or indirectly)
1790 100 times more than it has returned. This probably indicates an
1791 infinite recursion, unless you're writing strange benchmark programs, in
1792 which case it indicates something else.
1794 This threshold can be changed from 100, by recompiling the F<perl> binary,
1795 setting the C pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value.
1797 =item (?(DEFINE)....) does not allow branches in regex; marked by
1798 S<<-- HERE> in m/%s/
1800 (F) You used something like C<(?(DEFINE)...|..)> which is illegal. The
1801 most likely cause of this error is that you left out a parenthesis inside
1802 of the C<....> part.
1804 The <-- HERE shows whereabouts in the regular expression the problem was
1807 =item %s defines neither package nor VERSION--version check failed
1809 (F) You said something like "use Module 42" but in the Module file
1810 there are neither package declarations nor a C<$VERSION>.
1812 =item delete argument is index/value array slice, use array slice
1814 (F) You used index/value array slice syntax (C<%array[...]>) as
1815 the argument to C<delete>. You probably meant C<@array[...]> with
1816 an @ symbol instead.
1818 =item delete argument is key/value hash slice, use hash slice
1820 (F) You used key/value hash slice syntax (C<%hash{...}>) as the argument to
1821 C<delete>. You probably meant C<@hash{...}> with an @ symbol instead.
1823 =item delete argument is not a HASH or ARRAY element or slice
1825 (F) The argument to C<delete> must be either a hash or array element,
1831 or a hash or array slice, such as:
1833 @foo[$bar, $baz, $xyzzy]
1834 @{$ref->[12]}{"susie", "queue"}
1836 =item Delimiter for here document is too long
1838 (F) In a here document construct like C<<<FOO>, the label C<FOO> is too
1839 long for Perl to handle. You have to be seriously twisted to write code
1840 that triggers this error.
1842 =item Deprecated use of my() in false conditional
1844 (D deprecated) You used a declaration similar to C<my $x if 0>. There
1845 has been a long-standing bug in Perl that causes a lexical variable
1846 not to be cleared at scope exit when its declaration includes a false
1847 conditional. Some people have exploited this bug to achieve a kind of
1848 static variable. Since we intend to fix this bug, we don't want people
1849 relying on this behavior. You can achieve a similar static effect by
1850 declaring the variable in a separate block outside the function, eg
1852 sub f { my $x if 0; return $x++ }
1856 { my $x; sub f { return $x++ } }
1858 Beginning with perl 5.10.0, you can also use C<state> variables to have
1859 lexicals that are initialized only once (see L<feature>):
1861 sub f { state $x; return $x++ }
1863 =item DESTROY created new reference to dead object '%s'
1865 (F) A DESTROY() method created a new reference to the object which is
1866 just being DESTROYed. Perl is confused, and prefers to abort rather
1867 than to create a dangling reference.
1869 =item Did not produce a valid header
1873 =item %s did not return a true value
1875 (F) A required (or used) file must return a true value to indicate that
1876 it compiled correctly and ran its initialization code correctly. It's
1877 traditional to end such a file with a "1;", though any true value would
1878 do. See L<perlfunc/require>.
1880 =item (Did you mean &%s instead?)
1882 (W misc) You probably referred to an imported subroutine &FOO as $FOO or
1885 =item (Did you mean "local" instead of "our"?)
1887 (W misc) Remember that "our" does not localize the declared global
1888 variable. You have declared it again in the same lexical scope, which
1891 =item (Did you mean $ or @ instead of %?)
1893 (W) You probably said %hash{$key} when you meant $hash{$key} or
1894 @hash{@keys}. On the other hand, maybe you just meant %hash and got
1899 (F) You passed die() an empty string (the equivalent of C<die "">) or
1900 you called it with no args and C<$@> was empty.
1902 =item Document contains no data
1906 =item %s does not define %s::VERSION--version check failed
1908 (F) You said something like "use Module 42" but the Module did not
1909 define a C<$VERSION>.
1911 =item '/' does not take a repeat count
1913 (F) You cannot put a repeat count of any kind right after the '/' code.
1914 See L<perlfunc/pack>.
1916 =item Don't know how to get file name
1918 (P) C<PerlIO_getname>, a perl internal I/O function specific to VMS, was
1919 somehow called on another platform. This should not happen.
1921 =item Don't know how to handle magic of type \%o
1923 (P) The internal handling of magical variables has been cursed.
1925 =item do_study: out of memory
1927 (P) This should have been caught by safemalloc() instead.
1929 =item (Do you need to predeclare %s?)
1931 (S syntax) This is an educated guess made in conjunction with the message
1932 "%s found where operator expected". It often means a subroutine or module
1933 name is being referenced that hasn't been declared yet. This may be
1934 because of ordering problems in your file, or because of a missing
1935 "sub", "package", "require", or "use" statement. If you're referencing
1936 something that isn't defined yet, you don't actually have to define the
1937 subroutine or package before the current location. You can use an empty
1938 "sub foo;" or "package FOO;" to enter a "forward" declaration.
1940 =item dump() better written as CORE::dump()
1942 (W misc) You used the obsolescent C<dump()> built-in function, without fully
1943 qualifying it as C<CORE::dump()>. Maybe it's a typo. See L<perlfunc/dump>.
1945 =item dump is not supported
1947 (F) Your machine doesn't support dump/undump.
1949 =item Duplicate free() ignored
1951 (S malloc) An internal routine called free() on something that had
1954 =item Duplicate modifier '%c' after '%c' in %s
1956 (W unpack) You have applied the same modifier more than once after a
1957 type in a pack template. See L<perlfunc/pack>.
1959 =item each on reference is experimental
1961 (S experimental::autoderef) C<each> with a scalar argument is experimental
1962 and may change or be removed in a future Perl version. If you want to
1963 take the risk of using this feature, simply disable this warning:
1965 no warnings "experimental::autoderef";
1967 =item elseif should be elsif
1969 (S syntax) There is no keyword "elseif" in Perl because Larry thinks
1970 it's ugly. Your code will be interpreted as an attempt to call a method
1971 named "elseif" for the class returned by the following block. This is
1972 unlikely to be what you want.
1974 =item Empty \%c{} in regex; marked by S<<-- HERE> in m/%s/
1976 (F) C<\p> and C<\P> are used to introduce a named Unicode property, as
1977 described in L<perlunicode> and L<perlre>. You used C<\p> or C<\P> in
1978 a regular expression without specifying the property name.
1980 =item entering effective %s failed
1982 (F) While under the C<use filetest> pragma, switching the real and
1983 effective uids or gids failed.
1985 =item %ENV is aliased to %s
1987 (F) You're running under taint mode, and the C<%ENV> variable has been
1988 aliased to another hash, so it doesn't reflect anymore the state of the
1989 program's environment. This is potentially insecure.
1991 =item Error converting file specification %s
1993 (F) An error peculiar to VMS. Because Perl may have to deal with file
1994 specifications in either VMS or Unix syntax, it converts them to a
1995 single form when it must operate on them directly. Either you've passed
1996 an invalid file specification to Perl, or you've found a case the
1997 conversion routines don't handle. Drat.
1999 =item Eval-group in insecure regular expression
2001 (F) Perl detected tainted data when trying to compile a regular
2002 expression that contains the C<(?{ ... })> zero-width assertion, which
2003 is unsafe. See L<perlre/(?{ code })>, and L<perlsec>.
2005 =item Eval-group not allowed at runtime, use re 'eval' in regex m/%s/
2007 (F) Perl tried to compile a regular expression containing the
2008 C<(?{ ... })> zero-width assertion at run time, as it would when the
2009 pattern contains interpolated values. Since that is a security risk,
2010 it is not allowed. If you insist, you may still do this by using the
2011 C<re 'eval'> pragma or by explicitly building the pattern from an
2012 interpolated string at run time and using that in an eval(). See
2013 L<perlre/(?{ code })>.
2015 =item Eval-group not allowed, use re 'eval' in regex m/%s/
2017 (F) A regular expression contained the C<(?{ ... })> zero-width
2018 assertion, but that construct is only allowed when the C<use re 'eval'>
2019 pragma is in effect. See L<perlre/(?{ code })>.
2021 =item EVAL without pos change exceeded limit in regex; marked by
2022 S<<-- HERE> in m/%s/
2024 (F) You used a pattern that nested too many EVAL calls without consuming
2025 any text. Restructure the pattern so that text is consumed.
2027 The <-- HERE shows whereabouts in the regular expression the problem was
2030 =item Excessively long <> operator
2032 (F) The contents of a <> operator may not exceed the maximum size of a
2033 Perl identifier. If you're just trying to glob a long list of
2034 filenames, try using the glob() operator, or put the filenames into a
2035 variable and glob that.
2037 =item exec? I'm not *that* kind of operating system
2039 (F) The C<exec> function is not implemented on some systems, e.g., Symbian
2040 OS. See L<perlport>.
2042 =item Execution of %s aborted due to compilation errors.
2044 (F) The final summary message when a Perl compilation fails.
2046 =item exists argument is not a HASH or ARRAY element or a subroutine
2048 (F) The argument to C<exists> must be a hash or array element or a
2049 subroutine with an ampersand, such as:
2055 =item exists argument is not a subroutine name
2057 (F) The argument to C<exists> for C<exists &sub> must be a subroutine name,
2058 and not a subroutine call. C<exists &sub()> will generate this error.
2060 =item Exiting eval via %s
2062 (W exiting) You are exiting an eval by unconventional means, such as a
2063 goto, or a loop control statement.
2065 =item Exiting format via %s
2067 (W exiting) You are exiting a format by unconventional means, such as a
2068 goto, or a loop control statement.
2070 =item Exiting pseudo-block via %s
2072 (W exiting) You are exiting a rather special block construct (like a
2073 sort block or subroutine) by unconventional means, such as a goto, or a
2074 loop control statement. See L<perlfunc/sort>.
2076 =item Exiting subroutine via %s
2078 (W exiting) You are exiting a subroutine by unconventional means, such
2079 as a goto, or a loop control statement.
2081 =item Exiting substitution via %s
2083 (W exiting) You are exiting a substitution by unconventional means, such
2084 as a return, a goto, or a loop control statement.
2086 =item Expecting close bracket in regex; marked by S<<-- HERE> in m/%s/
2088 (F) You wrote something like
2092 to denote a capturing group of the form
2093 L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>,
2094 but omitted the C<")">.
2096 =item Expecting '(?flags:(?[...' in regex; marked by S<<-- HERE> in m/%s/
2098 (F) The C<(?[...])> extended character class regular expression construct
2099 only allows character classes (including character class escapes like
2100 C<\d>), operators, and parentheses. The one exception is C<(?flags:...)>
2101 containing at least one flag and exactly one C<(?[...])> construct.
2102 This allows a regular expression containing just C<(?[...])> to be
2103 interpolated. If you see this error message, then you probably
2104 have some other C<(?...)> construct inside your character class. See
2105 L<perlrecharclass/Extended Bracketed Character Classes>.
2107 =item Experimental aliasing via reference not enabled
2109 (F) To do aliasing via references, you must first enable the feature:
2111 no warnings "experimental::refaliasing";
2112 use feature "refaliasing";
2115 =item Experimental subroutine signatures not enabled
2117 (F) To use subroutine signatures, you must first enable them:
2119 no warnings "experimental::signatures";
2120 use feature "signatures";
2121 sub foo ($left, $right) { ... }
2123 =item Experimental "%s" subs not enabled
2125 (F) To use lexical subs, you must first enable them:
2127 no warnings 'experimental::lexical_subs';
2128 use feature 'lexical_subs';
2131 =item Explicit blessing to '' (assuming package main)
2133 (W misc) You are blessing a reference to a zero length string. This has
2134 the effect of blessing the reference into the package main. This is
2135 usually not what you want. Consider providing a default target package,
2136 e.g. bless($ref, $p || 'MyPackage');
2138 =item %s: Expression syntax
2140 (A) You've accidentally run your script through B<csh> instead of Perl.
2141 Check the #! line, or manually feed your script into Perl yourself.
2143 =item %s failed--call queue aborted
2145 (F) An untrapped exception was raised while executing a UNITCHECK,
2146 CHECK, INIT, or END subroutine. Processing of the remainder of the
2147 queue of such routines has been prematurely ended.
2149 =item False [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
2151 (W regexp)(F) A character class range must start and end at a literal
2152 character, not another character class like C<\d> or C<[:alpha:]>. The "-"
2153 in your false range is interpreted as a literal "-". In a C<(?[...])>
2154 construct, this is an error, rather than a warning. Consider quoting
2155 the "-", "\-". The S<<-- HERE> shows whereabouts in the regular expression
2156 the problem was discovered. See L<perlre>.
2158 =item Fatal VMS error (status=%d) at %s, line %d
2160 (P) An error peculiar to VMS. Something untoward happened in a VMS
2161 system service or RTL routine; Perl's exit status should provide more
2162 details. The filename in "at %s" and the line number in "line %d" tell
2163 you which section of the Perl source code is distressed.
2165 =item fcntl is not implemented
2167 (F) Your machine apparently doesn't implement fcntl(). What is this, a
2168 PDP-11 or something?
2170 =item FETCHSIZE returned a negative value
2172 (F) A tied array claimed to have a negative number of elements, which
2175 =item Field too wide in 'u' format in pack
2177 (W pack) Each line in an uuencoded string starts with a length indicator
2178 which can't encode values above 63. So there is no point in asking for
2179 a line length bigger than that. Perl will behave as if you specified
2180 C<u63> as the format.
2182 =item Filehandle %s opened only for input
2184 (W io) You tried to write on a read-only filehandle. If you intended
2185 it to be a read-write filehandle, you needed to open it with "+<" or
2186 "+>" or "+>>" instead of with "<" or nothing. If you intended only to
2187 write the file, use ">" or ">>". See L<perlfunc/open>.
2189 =item Filehandle %s opened only for output
2191 (W io) You tried to read from a filehandle opened only for writing, If
2192 you intended it to be a read/write filehandle, you needed to open it
2193 with "+<" or "+>" or "+>>" instead of with ">". If you intended only to
2194 read from the file, use "<". See L<perlfunc/open>. Another possibility
2195 is that you attempted to open filedescriptor 0 (also known as STDIN) for
2196 output (maybe you closed STDIN earlier?).
2198 =item Filehandle %s reopened as %s only for input
2200 (W io) You opened for reading a filehandle that got the same filehandle id
2201 as STDOUT or STDERR. This occurred because you closed STDOUT or STDERR
2204 =item Filehandle STDIN reopened as %s only for output
2206 (W io) You opened for writing a filehandle that got the same filehandle id
2207 as STDIN. This occurred because you closed STDIN previously.
2209 =item Final $ should be \$ or $name
2211 (F) You must now decide whether the final $ in a string was meant to be
2212 a literal dollar sign, or was meant to introduce a variable name that
2213 happens to be missing. So you have to put either the backslash or the
2216 =item flock() on closed filehandle %s
2218 (W closed) The filehandle you're attempting to flock() got itself closed
2219 some time before now. Check your control flow. flock() operates on
2220 filehandles. Are you attempting to call flock() on a dirhandle by the
2223 =item Format not terminated
2225 (F) A format must be terminated by a line with a solitary dot. Perl got
2226 to the end of your file without finding such a line.
2228 =item Format %s redefined
2230 (W redefine) You redefined a format. To suppress this warning, say
2233 no warnings 'redefine';
2234 eval "format NAME =...";
2237 =item Found = in conditional, should be ==
2247 (or something like that).
2249 =item %s found where operator expected
2251 (S syntax) The Perl lexer knows whether to expect a term or an operator.
2252 If it sees what it knows to be a term when it was expecting to see an
2253 operator, it gives you this warning. Usually it indicates that an
2254 operator or delimiter was omitted, such as a semicolon.
2256 =item gdbm store returned %d, errno %d, key "%s"
2258 (S) A warning from the GDBM_File extension that a store failed.
2260 =item gethostent not implemented
2262 (F) Your C library apparently doesn't implement gethostent(), probably
2263 because if it did, it'd feel morally obligated to return every hostname
2266 =item get%sname() on closed socket %s
2268 (W closed) You tried to get a socket or peer socket name on a closed
2269 socket. Did you forget to check the return value of your socket() call?
2271 =item getpwnam returned invalid UIC %#o for user "%s"
2273 (S) A warning peculiar to VMS. The call to C<sys$getuai> underlying the
2274 C<getpwnam> operator returned an invalid UIC.
2276 =item getsockopt() on closed socket %s
2278 (W closed) You tried to get a socket option on a closed socket. Did you
2279 forget to check the return value of your socket() call? See
2280 L<perlfunc/getsockopt>.
2282 =item given is experimental
2284 (S experimental::smartmatch) C<given> depends on smartmatch, which
2285 is experimental, so its behavior may change or even be removed
2286 in any future release of perl. See the explanation under
2287 L<perlsyn/Experimental Details on given and when>.
2289 =item Global symbol "%s" requires explicit package name (did you forget to
2292 (F) You've said "use strict" or "use strict vars", which indicates
2293 that all variables must either be lexically scoped (using "my" or "state"),
2294 declared beforehand using "our", or explicitly qualified to say
2295 which package the global variable is in (using "::").
2297 =item glob failed (%s)
2299 (S glob) Something went wrong with the external program(s) used
2300 for C<glob> and C<< <*.c> >>. Usually, this means that you supplied a C<glob>
2301 pattern that caused the external program to fail and exit with a
2302 nonzero status. If the message indicates that the abnormal exit
2303 resulted in a coredump, this may also mean that your csh (C shell)
2304 is broken. If so, you should change all of the csh-related variables
2305 in config.sh: If you have tcsh, make the variables refer to it as
2306 if it were csh (e.g. C<full_csh='/usr/bin/tcsh'>); otherwise, make them
2307 all empty (except that C<d_csh> should be C<'undef'>) so that Perl will
2308 think csh is missing. In either case, after editing config.sh, run
2309 C<./Configure -S> and rebuild Perl.
2311 =item Glob not terminated
2313 (F) The lexer saw a left angle bracket in a place where it was expecting
2314 a term, so it's looking for the corresponding right angle bracket, and
2315 not finding it. Chances are you left some needed parentheses out
2316 earlier in the line, and you really meant a "less than".
2318 =item gmtime(%f) failed
2320 (W overflow) You called C<gmtime> with a number that it could not handle:
2321 too large, too small, or NaN. The returned value is C<undef>.
2323 =item gmtime(%f) too large
2325 (W overflow) You called C<gmtime> with a number that was larger than
2326 it can reliably handle and C<gmtime> probably returned the wrong
2327 date. This warning is also triggered with NaN (the special
2328 not-a-number value).
2330 =item gmtime(%f) too small
2332 (W overflow) You called C<gmtime> with a number that was smaller than
2333 it can reliably handle and C<gmtime> probably returned the wrong date.
2335 =item Got an error from DosAllocMem
2337 (P) An error peculiar to OS/2. Most probably you're using an obsolete
2338 version of Perl, and this should not happen anyway.
2340 =item goto must have label
2342 (F) Unlike with "next" or "last", you're not allowed to goto an
2343 unspecified destination. See L<perlfunc/goto>.
2345 =item Goto undefined subroutine%s
2347 (F) You tried to call a subroutine with C<goto &sub> syntax, but
2348 the indicated subroutine hasn't been defined, or if it was, it
2349 has since been undefined.
2351 =item Group name must start with a non-digit word character in regex; marked by
2352 S<<-- HERE> in m/%s/
2354 (F) Group names must follow the rules for perl identifiers, meaning
2355 they must start with a non-digit word character. A common cause of
2356 this error is using (?&0) instead of (?0). See L<perlre>.
2358 =item ()-group starts with a count
2360 (F) A ()-group started with a count. A count is supposed to follow
2361 something: a template character or a ()-group. See L<perlfunc/pack>.
2363 =item %s had compilation errors.
2365 (F) The final summary message when a C<perl -c> fails.
2367 =item Had to create %s unexpectedly
2369 (S internal) A routine asked for a symbol from a symbol table that ought
2370 to have existed already, but for some reason it didn't, and had to be
2371 created on an emergency basis to prevent a core dump.
2373 =item %s has too many errors
2375 (F) The parser has given up trying to parse the program after 10 errors.
2376 Further error messages would likely be uninformative.
2378 =item Having more than one /%c regexp modifier is deprecated
2380 (D deprecated, regexp) You used the indicated regular expression pattern
2381 modifier at least twice in a string of modifiers. It is deprecated to
2382 do this with this particular modifier, to allow future extensions to the
2385 =item Hexadecimal float: exponent overflow
2387 (W overflow) The hexadecimal floating point has a larger exponent
2388 than the floating point supports.
2390 =item Hexadecimal float: exponent underflow
2392 (W overflow) The hexadecimal floating point has a smaller exponent
2393 than the floating point supports.
2395 =item Hexadecimal float: internal error
2397 (F) Something went horribly bad in hexadecimal float handling.
2399 =item Hexadecimal float: mantissa overflow
2401 (W overflow) The hexadecimal floating point literal had more bits in
2402 the mantissa (the part between the 0x and the exponent, also known as
2403 the fraction or the significand) than the floating point supports.
2405 =item Hexadecimal float: precision loss
2407 (W overflow) The hexadecimal floating point had internally more
2408 digits than could be output. This can be caused by unsupported
2409 long double formats, or by 64-bit integers not being available
2410 (needed to retrieve the digits under some configurations).
2412 =item Hexadecimal float: unsupported long double format
2414 (F) You have configured Perl to use long doubles but
2415 the internals of the long double format are unknown;
2416 therefore the hexadecimal float output is impossible.
2418 =item Hexadecimal number > 0xffffffff non-portable
2420 (W portable) The hexadecimal number you specified is larger than 2**32-1
2421 (4294967295) and therefore non-portable between systems. See
2422 L<perlport> for more on portability concerns.
2424 =item Identifier too long
2426 (F) Perl limits identifiers (names for variables, functions, etc.) to
2427 about 250 characters for simple names, and somewhat more for compound
2428 names (like C<$A::B>). You've exceeded Perl's limits. Future versions
2429 of Perl are likely to eliminate these arbitrary limitations.
2431 =item Ignoring zero length \N{} in character class in regex; marked by
2432 S<<-- HERE> in m/%s/
2434 (W regexp) Named Unicode character escapes (C<\N{...}>) may return a
2435 zero-length sequence. When such an escape is used in a character
2436 class its behavior is not well defined. Check that the correct
2437 escape has been used, and the correct charname handler is in scope.
2439 =item Illegal binary digit %s
2441 (F) You used a digit other than 0 or 1 in a binary number.
2443 =item Illegal binary digit %s ignored
2445 (W digit) You may have tried to use a digit other than 0 or 1 in a
2446 binary number. Interpretation of the binary number stopped before the
2449 =item Illegal character after '_' in prototype for %s : %s
2451 (W illegalproto) An illegal character was found in a prototype
2452 declaration. The '_' in a prototype must be followed by a ';',
2453 indicating the rest of the parameters are optional, or one of '@'
2454 or '%', since those two will accept 0 or more final parameters.
2456 =item Illegal character \%o (carriage return)
2458 (F) Perl normally treats carriage returns in the program text as it
2459 would any other whitespace, which means you should never see this error
2460 when Perl was built using standard options. For some reason, your
2461 version of Perl appears to have been built without this support. Talk
2462 to your Perl administrator.
2464 =item Illegal character in prototype for %s : %s
2466 (W illegalproto) An illegal character was found in a prototype declaration.
2467 Legal characters in prototypes are $, @, %, *, ;, [, ], &, \, and +.
2468 Perhaps you were trying to write a subroutine signature but didn't enable
2469 that feature first (C<use feature 'signatures'>), so your signature was
2470 instead interpreted as a bad prototype.
2472 =item Illegal declaration of anonymous subroutine
2474 (F) When using the C<sub> keyword to construct an anonymous subroutine,
2475 you must always specify a block of code. See L<perlsub>.
2477 =item Illegal declaration of subroutine %s
2479 (F) A subroutine was not declared correctly. See L<perlsub>.
2481 =item Illegal division by zero
2483 (F) You tried to divide a number by 0. Either something was wrong in
2484 your logic, or you need to put a conditional in to guard against
2487 =item Illegal hexadecimal digit %s ignored
2489 (W digit) You may have tried to use a character other than 0 - 9 or
2490 A - F, a - f in a hexadecimal number. Interpretation of the hexadecimal
2491 number stopped before the illegal character.
2493 =item Illegal modulus zero
2495 (F) You tried to divide a number by 0 to get the remainder. Most
2496 numbers don't take to this kindly.
2498 =item Illegal number of bits in vec
2500 (F) The number of bits in vec() (the third argument) must be a power of
2501 two from 1 to 32 (or 64, if your platform supports that).
2503 =item Illegal octal digit %s
2505 (F) You used an 8 or 9 in an octal number.
2507 =item Illegal octal digit %s ignored
2509 (W digit) You may have tried to use an 8 or 9 in an octal number.
2510 Interpretation of the octal number stopped before the 8 or 9.
2512 =item Illegal pattern in regex; marked by S<<-- HERE> in m/%s/
2514 (F) You wrote something like
2518 The C<"+"> is valid only when followed by digits, indicating a
2519 capturing group. See
2520 L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>.
2522 =item Illegal suidscript
2524 (F) The script run under suidperl was somehow illegal.
2526 =item Illegal switch in PERL5OPT: -%c
2528 (X) The PERL5OPT environment variable may only be used to set the
2529 following switches: B<-[CDIMUdmtw]>.
2531 =item Ill-formed CRTL environ value "%s"
2533 (W internal) A warning peculiar to VMS. Perl tried to read the CRTL's
2534 internal environ array, and encountered an element without the C<=>
2535 delimiter used to separate keys from values. The element is ignored.
2537 =item Ill-formed message in prime_env_iter: |%s|
2539 (W internal) A warning peculiar to VMS. Perl tried to read a logical
2540 name or CLI symbol definition when preparing to iterate over %ENV, and
2541 didn't see the expected delimiter between key and value, so the line was
2544 =item (in cleanup) %s
2546 (W misc) This prefix usually indicates that a DESTROY() method raised
2547 the indicated exception. Since destructors are usually called by the
2548 system at arbitrary points during execution, and often a vast number of
2549 times, the warning is issued only once for any number of failures that
2550 would otherwise result in the same message being repeated.
2552 Failure of user callbacks dispatched using the C<G_KEEPERR> flag could
2553 also result in this warning. See L<perlcall/G_KEEPERR>.
2555 =item Incomplete expression within '(?[ ])' in regex; marked by S<<-- HERE>
2558 (F) There was a syntax error within the C<(?[ ])>. This can happen if the
2559 expression inside the construct was completely empty, or if there are
2560 too many or few operands for the number of operators. Perl is not smart
2561 enough to give you a more precise indication as to what is wrong.
2563 =item Inconsistent hierarchy during C3 merge of class '%s': merging failed on
2566 (F) The method resolution order (MRO) of the given class is not
2567 C3-consistent, and you have enabled the C3 MRO for this class. See the C3
2568 documentation in L<mro> for more information.
2570 =item In EBCDIC the v-string components cannot exceed 2147483647
2572 (F) An error peculiar to EBCDIC. Internally, v-strings are stored as
2573 Unicode code points, and encoded in EBCDIC as UTF-EBCDIC. The UTF-EBCDIC
2574 encoding is limited to code points no larger than 2147483647 (0x7FFFFFFF).
2576 =item Infinite recursion in regex
2578 (F) You used a pattern that references itself without consuming any input
2579 text. You should check the pattern to ensure that recursive patterns
2580 either consume text or fail.
2582 =item Initialization of state variables in list context currently forbidden
2584 (F) Currently the implementation of "state" only permits the
2585 initialization of scalar variables in scalar context. Re-write
2586 C<state ($a) = 42> as C<state $a = 42> to change from list to scalar
2587 context. Constructions such as C<state (@a) = foo()> will be
2588 supported in a future perl release.
2590 =item %%s[%s] in scalar context better written as $%s[%s]
2592 (W syntax) In scalar context, you've used an array index/value slice
2593 (indicated by %) to select a single element of an array. Generally
2594 it's better to ask for a scalar value (indicated by $). The difference
2595 is that C<$foo[&bar]> always behaves like a scalar, both in the value it
2596 returns and when evaluating its argument, while C<%foo[&bar]> provides
2597 a list context to its subscript, which can do weird things if you're
2598 expecting only one subscript. When called in list context, it also
2599 returns the index (what C<&bar> returns) in addition to the value.
2601 =item %%s{%s} in scalar context better written as $%s{%s}
2603 (W syntax) In scalar context, you've used a hash key/value slice
2604 (indicated by %) to select a single element of a hash. Generally it's
2605 better to ask for a scalar value (indicated by $). The difference
2606 is that C<$foo{&bar}> always behaves like a scalar, both in the value
2607 it returns and when evaluating its argument, while C<@foo{&bar}> and
2608 provides a list context to its subscript, which can do weird things
2609 if you're expecting only one subscript. When called in list context,
2610 it also returns the key in addition to the value.
2612 =item Insecure dependency in %s
2614 (F) You tried to do something that the tainting mechanism didn't like.
2615 The tainting mechanism is turned on when you're running setuid or
2616 setgid, or when you specify B<-T> to turn it on explicitly. The
2617 tainting mechanism labels all data that's derived directly or indirectly
2618 from the user, who is considered to be unworthy of your trust. If any
2619 such data is used in a "dangerous" operation, you get this error. See
2620 L<perlsec> for more information.
2622 =item Insecure directory in %s
2624 (F) You can't use system(), exec(), or a piped open in a setuid or
2625 setgid script if C<$ENV{PATH}> contains a directory that is writable by
2626 the world. Also, the PATH must not contain any relative directory.
2629 =item Insecure $ENV{%s} while running %s
2631 (F) You can't use system(), exec(), or a piped open in a setuid or
2632 setgid script if any of C<$ENV{PATH}>, C<$ENV{IFS}>, C<$ENV{CDPATH}>,
2633 C<$ENV{ENV}>, C<$ENV{BASH_ENV}> or C<$ENV{TERM}> are derived from data
2634 supplied (or potentially supplied) by the user. The script must set
2635 the path to a known value, using trustworthy data. See L<perlsec>.
2637 =item Insecure user-defined property %s
2639 (F) Perl detected tainted data when trying to compile a regular
2640 expression that contains a call to a user-defined character property
2641 function, i.e. C<\p{IsFoo}> or C<\p{InFoo}>.
2642 See L<perlunicode/User-Defined Character Properties> and L<perlsec>.
2644 =item Integer overflow in format string for %s
2646 (F) The indexes and widths specified in the format string of C<printf()>
2647 or C<sprintf()> are too large. The numbers must not overflow the size of
2648 integers for your architecture.
2650 =item Integer overflow in %s number
2652 (S overflow) The hexadecimal, octal or binary number you have specified
2653 either as a literal or as an argument to hex() or oct() is too big for
2654 your architecture, and has been converted to a floating point number.
2655 On a 32-bit architecture the largest hexadecimal, octal or binary number
2656 representable without overflow is 0xFFFFFFFF, 037777777777, or
2657 0b11111111111111111111111111111111 respectively. Note that Perl
2658 transparently promotes all numbers to a floating point representation
2659 internally--subject to loss of precision errors in subsequent
2662 =item Integer overflow in srand
2664 (S overflow) The number you have passed to srand is too big to fit
2665 in your architecture's integer representation. The number has been
2666 replaced with the largest integer supported (0xFFFFFFFF on 32-bit
2667 architectures). This means you may be getting less randomness than
2668 you expect, because different random seeds above the maximum will
2669 return the same sequence of random numbers.
2671 =item Integer overflow in version
2673 =item Integer overflow in version %d
2675 (W overflow) Some portion of a version initialization is too large for
2676 the size of integers for your architecture. This is not a warning
2677 because there is no rational reason for a version to try and use an
2678 element larger than typically 2**32. This is usually caused by trying
2679 to use some odd mathematical operation as a version, like 100/9.
2681 =item Internal disaster in regex; marked by S<<-- HERE> in m/%s/
2683 (P) Something went badly wrong in the regular expression parser.
2684 The S<<-- HERE> shows whereabouts in the regular expression the problem was
2687 =item Internal inconsistency in tracking vforks
2689 (S) A warning peculiar to VMS. Perl keeps track of the number of times
2690 you've called C<fork> and C<exec>, to determine whether the current call
2691 to C<exec> should affect the current script or a subprocess (see
2692 L<perlvms/"exec LIST">). Somehow, this count has become scrambled, so
2693 Perl is making a guess and treating this C<exec> as a request to
2694 terminate the Perl script and execute the specified command.
2696 =item internal %<num>p might conflict with future printf extensions
2698 (S internal) Perl's internal routine that handles C<printf> and C<sprintf>
2699 formatting follows a slightly different set of rules when called from
2700 C or XS code. Specifically, formats consisting of digits followed
2701 by "p" (e.g., "%7p") are reserved for future use. If you see this
2702 message, then an XS module tried to call that routine with one such
2705 =item Internal urp in regex; marked by S<<-- HERE> in m/%s/
2707 (P) Something went badly awry in the regular expression parser. The
2708 S<<-- HERE> shows whereabouts in the regular expression the problem was
2711 =item %s (...) interpreted as function
2713 (W syntax) You've run afoul of the rule that says that any list operator
2714 followed by parentheses turns into a function, with all the list
2715 operators arguments found inside the parentheses. See
2716 L<perlop/Terms and List Operators (Leftward)>.
2718 =item In '(?...)', the '(' and '?' must be adjacent in regex;
2719 marked by S<<-- HERE> in m/%s/
2721 (F) The two-character sequence C<"(?"> in this context in a regular
2722 expression pattern should be an indivisible token, with nothing
2723 intervening between the C<"("> and the C<"?">, but you separated them
2726 =item Invalid %s attribute: %s
2728 (F) The indicated attribute for a subroutine or variable was not recognized
2729 by Perl or by a user-supplied handler. See L<attributes>.
2731 =item Invalid %s attributes: %s
2733 (F) The indicated attributes for a subroutine or variable were not
2734 recognized by Perl or by a user-supplied handler. See L<attributes>.
2736 =item Invalid character in charnames alias definition; marked by
2739 (F) You tried to create a custom alias for a character name, with
2740 the C<:alias> option to C<use charnames> and the specified character in
2741 the indicated name isn't valid. See L<charnames/CUSTOM ALIASES>.
2743 =item Invalid \0 character in %s for %s: %s\0%s
2745 (W syscalls) Embedded \0 characters in pathnames or other system call
2746 arguments produce a warning as of 5.20. The parts after the \0 were
2747 formerly ignored by system calls.
2749 =item Invalid character in \N{...}; marked by S<<-- HERE> in \N{%s}
2751 (F) Only certain characters are valid for character names. The
2752 indicated one isn't. See L<charnames/CUSTOM ALIASES>.
2754 =item Invalid conversion in %s: "%s"
2756 (W printf) Perl does not understand the given format conversion. See
2757 L<perlfunc/sprintf>.
2759 =item Invalid escape in the specified encoding in regex; marked by
2760 S<<-- HERE> in m/%s/
2762 (W regexp)(F) The numeric escape (for example C<\xHH>) of value < 256
2763 didn't correspond to a single character through the conversion
2764 from the encoding specified by the encoding pragma.
2765 The escape was replaced with REPLACEMENT CHARACTER (U+FFFD)
2766 instead, except within S<C<(?[ ])>>, where it is a fatal error.
2767 The S<<-- HERE> shows whereabouts in the regular expression the
2768 escape was discovered.
2770 =item Invalid hexadecimal number in \N{U+...}
2772 =item Invalid hexadecimal number in \N{U+...} in regex; marked by
2773 S<<-- HERE> in m/%s/
2775 (F) The character constant represented by C<...> is not a valid hexadecimal
2776 number. Either it is empty, or you tried to use a character other than
2777 0 - 9 or A - F, a - f in a hexadecimal number.
2779 =item Invalid module name %s with -%c option: contains single ':'
2781 (F) The module argument to perl's B<-m> and B<-M> command-line options
2782 cannot contain single colons in the module name, but only in the
2783 arguments after "=". In other words, B<-MFoo::Bar=:baz> is ok, but
2784 B<-MFoo:Bar=baz> is not.
2786 =item Invalid mro name: '%s'
2788 (F) You tried to C<mro::set_mro("classname", "foo")> or C<use mro 'foo'>,
2789 where C<foo> is not a valid method resolution order (MRO). Currently,
2790 the only valid ones supported are C<dfs> and C<c3>, unless you have loaded
2791 a module that is a MRO plugin. See L<mro> and L<perlmroapi>.
2793 =item Invalid negative number (%s) in chr
2795 (W utf8) You passed a negative number to C<chr>. Negative numbers are
2796 not valid character numbers, so it returns the Unicode replacement
2799 =item invalid option -D%c, use -D'' to see choices
2801 (S debugging) Perl was called with invalid debugger flags. Call perl
2802 with the B<-D> option with no flags to see the list of acceptable values.
2803 See also L<perlrun/-Dletters>.
2805 =item Invalid [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
2807 (F) The range specified in a character class had a minimum character
2808 greater than the maximum character. One possibility is that you forgot the
2809 C<{}> from your ending C<\x{}> - C<\x> without the curly braces can go only
2810 up to C<ff>. The S<<-- HERE> shows whereabouts in the regular expression the
2811 problem was discovered. See L<perlre>.
2813 =item Invalid range "%s" in transliteration operator
2815 (F) The range specified in the tr/// or y/// operator had a minimum
2816 character greater than the maximum character. See L<perlop>.
2818 =item Invalid separator character %s in attribute list
2820 (F) Something other than a colon or whitespace was seen between the
2821 elements of an attribute list. If the previous attribute had a
2822 parenthesised parameter list, perhaps that list was terminated too soon.
2825 =item Invalid separator character %s in PerlIO layer specification %s
2827 (W layer) When pushing layers onto the Perl I/O system, something other
2828 than a colon or whitespace was seen between the elements of a layer list.
2829 If the previous attribute had a parenthesised parameter list, perhaps that
2830 list was terminated too soon.
2832 =item Invalid strict version format (%s)
2834 (F) A version number did not meet the "strict" criteria for versions.
2835 A "strict" version number is a positive decimal number (integer or
2836 decimal-fraction) without exponentiation or else a dotted-decimal
2837 v-string with a leading 'v' character and at least three components.
2838 The parenthesized text indicates which criteria were not met.
2839 See the L<version> module for more details on allowed version formats.
2841 =item Invalid type '%s' in %s
2843 (F) The given character is not a valid pack or unpack type.
2844 See L<perlfunc/pack>.
2846 (W) The given character is not a valid pack or unpack type but used to be
2849 =item Invalid version format (%s)
2851 (F) A version number did not meet the "lax" criteria for versions.
2852 A "lax" version number is a positive decimal number (integer or
2853 decimal-fraction) without exponentiation or else a dotted-decimal
2854 v-string. If the v-string has fewer than three components, it
2855 must have a leading 'v' character. Otherwise, the leading 'v' is
2856 optional. Both decimal and dotted-decimal versions may have a
2857 trailing "alpha" component separated by an underscore character
2858 after a fractional or dotted-decimal component. The parenthesized
2859 text indicates which criteria were not met. See the L<version> module
2860 for more details on allowed version formats.
2862 =item Invalid version object
2864 (F) The internal structure of the version object was invalid.
2865 Perhaps the internals were modified directly in some way or
2866 an arbitrary reference was blessed into the "version" class.
2868 =item In '(*VERB...)', the '(' and '*' must be adjacent in regex;
2869 marked by S<<-- HERE> in m/%s/
2871 (F) The two-character sequence C<"(*"> in
2872 this context in a regular expression pattern should be an
2873 indivisible token, with nothing intervening between the C<"(">
2874 and the C<"*">, but you separated them.
2876 =item ioctl is not implemented
2878 (F) Your machine apparently doesn't implement ioctl(), which is pretty
2879 strange for a machine that supports C.
2881 =item ioctl() on unopened %s
2883 (W unopened) You tried ioctl() on a filehandle that was never opened.
2884 Check your control flow and number of arguments.
2886 =item IO layers (like '%s') unavailable
2888 (F) Your Perl has not been configured to have PerlIO, and therefore
2889 you cannot use IO layers. To have PerlIO, Perl must be configured
2892 =item IO::Socket::atmark not implemented on this architecture
2894 (F) Your machine doesn't implement the sockatmark() functionality,
2895 neither as a system call nor an ioctl call (SIOCATMARK).
2897 =item "%s" is more clearly written simply as "%s" in regex; marked by <-- HERE in m/%s/
2899 (W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
2901 You specified a character that has the given plainer way of writing it,
2902 and which is also portable to platforms running with different character
2905 =item $* is no longer supported
2907 (D deprecated, syntax) The special variable C<$*>, deprecated in older
2908 perls, has been removed as of 5.10.0 and is no longer supported. In
2909 previous versions of perl the use of C<$*> enabled or disabled multi-line
2910 matching within a string.
2912 Instead of using C<$*> you should use the C</m> (and maybe C</s>) regexp
2913 modifiers. You can enable C</m> for a lexical scope (even a whole file)
2914 with C<use re '/m'>. (In older versions: when C<$*> was set to a true value
2915 then all regular expressions behaved as if they were written using C</m>.)
2917 =item $# is no longer supported
2919 (D deprecated, syntax) The special variable C<$#>, deprecated in older
2920 perls, has been removed as of 5.10.0 and is no longer supported. You
2921 should use the printf/sprintf functions instead.
2923 =item '%s' is not a code reference
2925 (W overload) The second (fourth, sixth, ...) argument of
2926 overload::constant needs to be a code reference. Either
2927 an anonymous subroutine, or a reference to a subroutine.
2929 =item '%s' is not an overloadable type
2931 (W overload) You tried to overload a constant type the overload package is
2934 =item -i used with no filenames on the command line, reading from STDIN
2936 (S inplace) The C<-i> option was passed on the command line, indicating
2937 that the script is intended to edit files in place, but no files were
2938 given. This is usually a mistake, since editing STDIN in place doesn't
2939 make sense, and can be confusing because it can make perl look like
2940 it is hanging when it is really just trying to read from STDIN. You
2941 should either pass a filename to edit, or remove C<-i> from the command
2942 line. See L<perlrun> for more details.
2944 =item Junk on end of regexp in regex m/%s/
2946 (P) The regular expression parser is confused.
2948 =item keys on reference is experimental
2950 (S experimental::autoderef) C<keys> with a scalar argument is experimental
2951 and may change or be removed in a future Perl version. If you want to
2952 take the risk of using this feature, simply disable this warning:
2954 no warnings "experimental::autoderef";
2956 =item Label not found for "last %s"
2958 (F) You named a loop to break out of, but you're not currently in a loop
2959 of that name, not even if you count where you were called from. See
2962 =item Label not found for "next %s"
2964 (F) You named a loop to continue, but you're not currently in a loop of
2965 that name, not even if you count where you were called from. See
2968 =item Label not found for "redo %s"
2970 (F) You named a loop to restart, but you're not currently in a loop of
2971 that name, not even if you count where you were called from. See
2974 =item leaving effective %s failed
2976 (F) While under the C<use filetest> pragma, switching the real and
2977 effective uids or gids failed.
2979 =item length/code after end of string in unpack
2981 (F) While unpacking, the string buffer was already used up when an unpack
2982 length/code combination tried to obtain more data. This results in
2983 an undefined value for the length. See L<perlfunc/pack>.
2985 =item length() used on %s (did you mean "scalar(%s)"?)
2987 (W syntax) You used length() on either an array or a hash when you
2988 probably wanted a count of the items.
2990 Array size can be obtained by doing:
2994 The number of items in a hash can be obtained by doing:
2998 =item Lexing code attempted to stuff non-Latin-1 character into Latin-1 input
3000 (F) An extension is attempting to insert text into the current parse
3001 (using L<lex_stuff_pvn|perlapi/lex_stuff_pvn> or similar), but tried to insert a character that
3002 couldn't be part of the current input. This is an inherent pitfall
3003 of the stuffing mechanism, and one of the reasons to avoid it. Where
3004 it is necessary to stuff, stuffing only plain ASCII is recommended.
3006 =item Lexing code internal error (%s)
3008 (F) Lexing code supplied by an extension violated the lexer's API in a
3011 =item listen() on closed socket %s
3013 (W closed) You tried to do a listen on a closed socket. Did you forget
3014 to check the return value of your socket() call? See
3017 =item List form of piped open not implemented
3019 (F) On some platforms, notably Windows, the three-or-more-arguments
3020 form of C<open> does not support pipes, such as C<open($pipe, '|-', @args)>.
3021 Use the two-argument C<open($pipe, '|prog arg1 arg2...')> form instead.
3023 =item %s: loadable library and perl binaries are mismatched (got handshake key %p, needed %p)
3025 (P) A dynamic loading library C<.so> or C<.dll> was being loaded into the
3026 process that was built against a different build of perl than the
3027 said library was compiled against. Reinstalling the XS module will
3028 likely fix this error.
3030 =item Locale '%s' may not work well.%s
3032 (W locale) You are using the named locale, which is a non-UTF-8 one, and
3033 which Perl has determined is not fully compatible with Perl. The second
3034 C<%s> gives a reason.
3036 By far the most common reason is that the locale has characters in it
3037 that are represented by more than one byte. The only such locales that
3038 Perl can handle are the UTF-8 locales. Most likely the specified locale
3039 is a non-UTF-8 one for an East Asian language such as Chinese or
3040 Japanese. If the locale is a superset of ASCII, the ASCII portion of it
3043 Some essentially obsolete locales that aren't supersets of ASCII, mainly
3044 those in ISO 646 or other 7-bit locales, such as ASMO 449, can also have
3045 problems, depending on what portions of the ASCII character set get
3046 changed by the locale and are also used by the program.
3047 The warning message lists the determinable conflicting characters.
3049 Note that not all incompatibilities are found.
3051 If this happens to you, there's not much you can do except switch to use a
3052 different locale or use L<Encode> to translate from the locale into
3053 UTF-8; if that's impracticable, you have been warned that some things
3056 This message is output once each time a bad locale is switched into
3057 within the scope of C<S<use locale>>, or on the first possibly-affected
3058 operation if the C<S<use locale>> inherits a bad one. It is not raised
3059 for any operations from the L<POSIX> module.
3061 =item localtime(%f) failed
3063 (W overflow) You called C<localtime> with a number that it could not handle:
3064 too large, too small, or NaN. The returned value is C<undef>.
3066 =item localtime(%f) too large
3068 (W overflow) You called C<localtime> with a number that was larger
3069 than it can reliably handle and C<localtime> probably returned the
3070 wrong date. This warning is also triggered with NaN (the special
3071 not-a-number value).
3073 =item localtime(%f) too small
3075 (W overflow) You called C<localtime> with a number that was smaller
3076 than it can reliably handle and C<localtime> probably returned the
3079 =item Lookbehind longer than %d not implemented in regex m/%s/
3081 (F) There is currently a limit on the length of string which lookbehind can
3082 handle. This restriction may be eased in a future release.
3084 =item Lost precision when %s %f by 1
3086 (W imprecision) The value you attempted to increment or decrement by one
3087 is too large for the underlying floating point representation to store
3088 accurately, hence the target of C<++> or C<--> is unchanged. Perl issues this
3089 warning because it has already switched from integers to floating point
3090 when values are too large for integers, and now even floating point is
3091 insufficient. You may wish to switch to using L<Math::BigInt> explicitly.
3093 =item lstat() on filehandle%s
3095 (W io) You tried to do an lstat on a filehandle. What did you mean
3096 by that? lstat() makes sense only on filenames. (Perl did a fstat()
3097 instead on the filehandle.)
3099 =item lvalue attribute %s already-defined subroutine
3101 (W misc) Although L<attributes.pm|attributes> allows this, turning the lvalue
3102 attribute on or off on a Perl subroutine that is already defined
3103 does not always work properly. It may or may not do what you
3104 want, depending on what code is inside the subroutine, with exact
3105 details subject to change between Perl versions. Only do this
3106 if you really know what you are doing.
3108 =item lvalue attribute ignored after the subroutine has been defined
3110 (W misc) Using the C<:lvalue> declarative syntax to make a Perl
3111 subroutine an lvalue subroutine after it has been defined is
3112 not permitted. To make the subroutine an lvalue subroutine,
3113 add the lvalue attribute to the definition, or put the C<sub
3114 foo :lvalue;> declaration before the definition.
3116 See also L<attributes.pm|attributes>.
3118 =item Magical list constants are not supported
3120 (F) You assigned a magical array to a stash element, and then tried
3121 to use the subroutine from the same slot. You are asking Perl to do
3122 something it cannot do, details subject to change between Perl versions.
3124 =item Malformed integer in [] in pack
3126 (F) Between the brackets enclosing a numeric repeat count only digits
3127 are permitted. See L<perlfunc/pack>.
3129 =item Malformed integer in [] in unpack
3131 (F) Between the brackets enclosing a numeric repeat count only digits
3132 are permitted. See L<perlfunc/pack>.
3134 =item Malformed PERLLIB_PREFIX
3136 (F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form
3143 with nonempty prefix1 and prefix2. If C<prefix1> is indeed a prefix of
3144 a builtin library search path, prefix2 is substituted. The error may
3145 appear if components are not found, or are too long. See
3146 "PERLLIB_PREFIX" in L<perlos2>.
3148 =item Malformed prototype for %s: %s
3150 (F) You tried to use a function with a malformed prototype. The
3151 syntax of function prototypes is given a brief compile-time check for
3152 obvious errors like invalid characters. A more rigorous check is run
3153 when the function is called.
3154 Perhaps the function's author was trying to write a subroutine signature
3155 but didn't enable that feature first (C<use feature 'signatures'>),
3156 so the signature was instead interpreted as a bad prototype.
3158 =item Malformed UTF-8 character (%s)
3160 (S utf8)(F) Perl detected a string that didn't comply with UTF-8
3161 encoding rules, even though it had the UTF8 flag on.
3163 One possible cause is that you set the UTF8 flag yourself for data that
3164 you thought to be in UTF-8 but it wasn't (it was for example legacy
3165 8-bit data). To guard against this, you can use Encode::decode_utf8.
3167 If you use the C<:encoding(UTF-8)> PerlIO layer for input, invalid byte
3168 sequences are handled gracefully, but if you use C<:utf8>, the flag is
3169 set without validating the data, possibly resulting in this error
3172 See also L<Encode/"Handling Malformed Data">.
3174 =item Malformed UTF-8 character immediately after '%s'
3176 (F) You said C<use utf8>, but the program file doesn't comply with UTF-8
3177 encoding rules. The message prints out the properly encoded characters
3178 just before the first bad one. If C<utf8> warnings are enabled, a
3179 warning is generated that gives more details about the type of
3182 =item Malformed UTF-8 returned by \N{%s} immediately after '%s'
3184 (F) The charnames handler returned malformed UTF-8.
3186 =item Malformed UTF-8 string in '%c' format in unpack
3188 (F) You tried to unpack something that didn't comply with UTF-8 encoding
3189 rules and perl was unable to guess how to make more progress.
3191 =item Malformed UTF-8 string in pack
3193 (F) You tried to pack something that didn't comply with UTF-8 encoding
3194 rules and perl was unable to guess how to make more progress.
3196 =item Malformed UTF-8 string in unpack
3198 (F) You tried to unpack something that didn't comply with UTF-8 encoding
3199 rules and perl was unable to guess how to make more progress.
3201 =item Malformed UTF-16 surrogate
3203 (F) Perl thought it was reading UTF-16 encoded character data but while
3204 doing it Perl met a malformed Unicode surrogate.
3206 =item Mandatory parameter follows optional parameter
3208 (F) In a subroutine signature, you wrote something like "$a = undef,
3209 $b", making an earlier parameter optional and a later one mandatory.
3210 Parameters are filled from left to right, so it's impossible for the
3211 caller to omit an earlier one and pass a later one. If you want to act
3212 as if the parameters are filled from right to left, declare the rightmost
3213 optional and then shuffle the parameters around in the subroutine's body.
3215 =item Matched non-Unicode code point 0x%X against Unicode property; may
3218 (S non_unicode) Perl allows strings to contain a superset of
3219 Unicode code points; each code point may be as large as what is storable
3220 in an unsigned integer on your system, but these may not be accepted by
3221 other languages/systems. This message occurs when you matched a string
3222 containing such a code point against a regular expression pattern, and
3223 the code point was matched against a Unicode property, C<\p{...}> or
3224 C<\P{...}>. Unicode properties are only defined on Unicode code points,
3225 so the result of this match is undefined by Unicode, but Perl (starting
3226 in v5.20) treats non-Unicode code points as if they were typical
3227 unassigned Unicode ones, and matched this one accordingly. Whether a
3228 given property matches these code points or not is specified in
3229 L<perluniprops/Properties accessible through \p{} and \P{}>.
3231 This message is suppressed (unless it has been made fatal) if it is
3232 immaterial to the results of the match if the code point is Unicode or
3233 not. For example, the property C<\p{ASCII_Hex_Digit}> only can match
3234 the 22 characters C<[0-9A-Fa-f]>, so obviously all other code points,
3235 Unicode or not, won't match it. (And C<\P{ASCII_Hex_Digit}> will match
3236 every code point except these 22.)
3238 Getting this message indicates that the outcome of the match arguably
3239 should have been the opposite of what actually happened. If you think
3240 that is the case, you may wish to make the C<non_unicode> warnings
3241 category fatal; if you agree with Perl's decision, you may wish to turn
3244 See L<perlunicode/Beyond Unicode code points> for more information.
3246 =item %s matches null string many times in regex; marked by S<<-- HERE> in
3249 (W regexp) The pattern you've specified would be an infinite loop if the
3250 regular expression engine didn't specifically check for that. The S<<-- HERE>
3251 shows whereabouts in the regular expression the problem was discovered.
3254 =item Maximal count of pending signals (%u) exceeded
3256 (F) Perl aborted due to too high a number of signals pending. This
3257 usually indicates that your operating system tried to deliver signals
3258 too fast (with a very high priority), starving the perl process from
3259 resources it would need to reach a point where it can process signals
3260 safely. (See L<perlipc/"Deferred Signals (Safe Signals)">.)
3262 =item "%s" may clash with future reserved word
3264 (W) This warning may be due to running a perl5 script through a perl4
3265 interpreter, especially if the word that is being warned about is
3268 =item '%' may not be used in pack
3270 (F) You can't pack a string by supplying a checksum, because the
3271 checksumming process loses information, and you can't go the other way.
3272 See L<perlfunc/unpack>.
3274 =item Method for operation %s not found in package %s during blessing
3276 (F) An attempt was made to specify an entry in an overloading table that
3277 doesn't resolve to a valid subroutine. See L<overload>.
3279 =item Method %s not permitted
3283 =item Might be a runaway multi-line %s string starting on line %d
3285 (S) An advisory indicating that the previous error may have been caused
3286 by a missing delimiter on a string or pattern, because it eventually
3287 ended earlier on the current line.
3289 =item Misplaced _ in number
3291 (W syntax) An underscore (underbar) in a numeric constant did not
3292 separate two digits.
3294 =item Missing argument in %s
3296 (W missing) You called a function with fewer arguments than other
3297 arguments you supplied indicated would be needed.
3299 Currently only emitted when a printf-type format required more
3300 arguments than were supplied, but might be used in the future for
3301 other cases where we can statically determine that arguments to
3302 functions are missing, e.g. for the L<perlfunc/pack> function.
3304 =item Ranges of ASCII printables should be some subset of "0-9", "A-Z", or
3305 "a-z" in regex; marked by <-- HERE in m/%s/
3307 (W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
3309 Stricter rules help to find typos and other errors. Perhaps you didn't
3310 even intend a range here, if the C<"-"> was meant to be some other
3311 character, or should have been escaped (like C<"\-">). If you did
3312 intend a range, the one that was used is not portable between ASCII and
3313 EBCDIC platforms, and doesn't have an obvious meaning to a casual
3316 [3-7] # OK; Obvious and portable
3317 [d-g] # OK; Obvious and portable
3318 [A-Y] # OK; Obvious and portable
3319 [A-z] # WRONG; Not portable; not clear what is meant
3320 [a-Z] # WRONG; Not portable; not clear what is meant
3321 [%-.] # WRONG; Not portable; not clear what is meant
3322 [\x41-Z] # WRONG; Not portable; not obvious to non-geek
3324 (You can force portability by specifying a Unicode range, which means that
3325 the endpoints are specified by
3326 L<C<\N{...}>|perlrecharclass/Character Ranges>, but the meaning may
3327 still not be obvious.)
3328 The stricter rules require that ranges that start or stop with an ASCII
3329 character that is not a control have all their endpoints be the literal
3330 character, and not some escape sequence (like C<"\x41">), and the ranges
3331 must be all digits, or all uppercase letters, or all lowercase letters.
3333 =item Ranges of digits should be from the same group in regex; marked by
3336 (W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
3338 Stricter rules help to find typos and other errors. You included a
3339 range, and at least one of the end points is a decimal digit. Under the
3340 stricter rules, when this happens, both end points should be digits in
3341 the same group of 10 consecutive digits.
3343 =item Missing argument to -%c
3345 (F) The argument to the indicated command line switch must follow
3346 immediately after the switch, without intervening spaces.
3348 =item Missing braces on \N{}
3350 =item Missing braces on \N{} in regex; marked by S<<-- HERE> in m/%s/
3352 (F) Wrong syntax of character name literal C<\N{charname}> within
3353 double-quotish context. This can also happen when there is a space
3354 (or comment) between the C<\N> and the C<{> in a regex with the C</x> modifier.
3355 This modifier does not change the requirement that the brace immediately
3358 =item Missing braces on \o{}
3360 (F) A C<\o> must be followed immediately by a C<{> in double-quotish context.
3362 =item Missing comma after first argument to %s function
3364 (F) While certain functions allow you to specify a filehandle or an
3365 "indirect object" before the argument list, this ain't one of them.
3367 =item Missing command in piped open
3369 (W pipe) You used the C<open(FH, "| command")> or
3370 C<open(FH, "command |")> construction, but the command was missing or
3373 =item Missing control char name in \c
3375 (F) A double-quoted string ended with "\c", without the required control
3378 =item Missing ']' in prototype for %s : %s
3380 (W illegalproto) A grouping was started with C<[> but never closed with C<]>.
3382 =item Missing name in "%s sub"
3384 (F) The syntax for lexically scoped subroutines requires that
3385 they have a name with which they can be found.
3387 =item Missing $ on loop variable
3389 (F) Apparently you've been programming in B<csh> too much. Variables
3390 are always mentioned with the $ in Perl, unlike in the shells, where it
3391 can vary from one line to the next.
3393 =item (Missing operator before %s?)
3395 (S syntax) This is an educated guess made in conjunction with the message
3396 "%s found where operator expected". Often the missing operator is a comma.
3398 =item Missing or undefined argument to require
3400 (F) You tried to call require with no argument or with an undefined
3401 value as an argument. Require expects either a package name or a
3402 file-specification as an argument. See L<perlfunc/require>.
3404 =item Missing right brace on \%c{} in regex; marked by S<<-- HERE> in m/%s/
3406 (F) Missing right brace in C<\x{...}>, C<\p{...}>, C<\P{...}>, or C<\N{...}>.
3408 =item Missing right brace on \N{}
3410 =item Missing right brace on \N{} or unescaped left brace after \N
3412 (F) C<\N> has two meanings.
3414 The traditional one has it followed by a name enclosed in braces,
3415 meaning the character (or sequence of characters) given by that
3416 name. Thus C<\N{ASTERISK}> is another way of writing C<*>, valid in both
3417 double-quoted strings and regular expression patterns. In patterns,
3418 it doesn't have the meaning an unescaped C<*> does.
3420 Starting in Perl 5.12.0, C<\N> also can have an additional meaning (only)
3421 in patterns, namely to match a non-newline character. (This is short
3422 for C<[^\n]>, and like C<.> but is not affected by the C</s> regex modifier.)
3424 This can lead to some ambiguities. When C<\N> is not followed immediately
3425 by a left brace, Perl assumes the C<[^\n]> meaning. Also, if the braces
3426 form a valid quantifier such as C<\N{3}> or C<\N{5,}>, Perl assumes that this
3427 means to match the given quantity of non-newlines (in these examples,
3428 3; and 5 or more, respectively). In all other case, where there is a
3429 C<\N{> and a matching C<}>, Perl assumes that a character name is desired.
3431 However, if there is no matching C<}>, Perl doesn't know if it was
3432 mistakenly omitted, or if C<[^\n]{> was desired, and raises this error.
3433 If you meant the former, add the right brace; if you meant the latter,
3434 escape the brace with a backslash, like so: C<\N\{>
3436 =item Missing right curly or square bracket
3438 (F) The lexer counted more opening curly or square brackets than closing
3439 ones. As a general rule, you'll find it's missing near the place you
3442 =item (Missing semicolon on previous line?)
3444 (S syntax) This is an educated guess made in conjunction with the message
3445 "%s found where operator expected". Don't automatically put a semicolon on
3446 the previous line just because you saw this message.
3448 =item Modification of a read-only value attempted
3450 (F) You tried, directly or indirectly, to change the value of a
3451 constant. You didn't, of course, try "2 = 1", because the compiler
3452 catches that. But an easy way to do the same thing is:
3454 sub mod { $_[0] = 1 }
3457 Another way is to assign to a substr() that's off the end of the string.
3459 Yet another way is to assign to a C<foreach> loop I<VAR> when I<VAR>
3460 is aliased to a constant in the look I<LIST>:
3463 foreach my $n ($x, 2) {
3464 $n *= 2; # modifies the $x, but fails on attempt to
3467 =item Modification of non-creatable array value attempted, %s
3469 (F) You tried to make an array value spring into existence, and the
3470 subscript was probably negative, even counting from end of the array
3473 =item Modification of non-creatable hash value attempted, %s
3475 (P) You tried to make a hash value spring into existence, and it
3476 couldn't be created for some peculiar reason.
3478 =item Module name must be constant
3480 (F) Only a bare module name is allowed as the first argument to a "use".
3482 =item Module name required with -%c option
3484 (F) The C<-M> or C<-m> options say that Perl should load some module, but
3485 you omitted the name of the module. Consult L<perlrun> for full details
3486 about C<-M> and C<-m>.
3488 =item More than one argument to '%s' open
3490 (F) The C<open> function has been asked to open multiple files. This
3491 can happen if you are trying to open a pipe to a command that takes a
3492 list of arguments, but have forgotten to specify a piped open mode.
3493 See L<perlfunc/open> for details.
3495 =item mprotect for COW string %p %u failed with %d
3497 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_COW (see
3498 L<perlguts/"Copy on Write">), but a shared string buffer
3499 could not be made read-only.
3501 =item mprotect for %p %u failed with %d
3503 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_OPS (see L<perlhacktips>),
3504 but an op tree could not be made read-only.
3506 =item mprotect RW for COW string %p %u failed with %d
3508 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_COW (see
3509 L<perlguts/"Copy on Write">), but a read-only shared string
3510 buffer could not be made mutable.
3512 =item mprotect RW for %p %u failed with %d
3514 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_OPS (see
3515 L<perlhacktips>), but a read-only op tree could not be made
3516 mutable before freeing the ops.
3518 =item msg%s not implemented
3520 (F) You don't have System V message IPC on your system.
3522 =item Multidimensional syntax %s not supported
3524 (W syntax) Multidimensional arrays aren't written like C<$foo[1,2,3]>.
3525 They're written like C<$foo[1][2][3]>, as in C.
3527 =item '/' must follow a numeric type in unpack
3529 (F) You had an unpack template that contained a '/', but this did not
3530 follow some unpack specification producing a numeric value.
3531 See L<perlfunc/pack>.
3533 =item "my sub" not yet implemented
3535 (F) Lexically scoped subroutines are not yet implemented. Don't try
3538 =item "my" subroutine %s can't be in a package
3540 (F) Lexically scoped subroutines aren't in a package, so it doesn't make
3541 sense to try to declare one with a package qualifier on the front.
3543 =item "my %s" used in sort comparison
3545 (W syntax) The package variables $a and $b are used for sort comparisons.
3546 You used $a or $b in as an operand to the C<< <=> >> or C<cmp> operator inside a
3547 sort comparison block, and the variable had earlier been declared as a
3548 lexical variable. Either qualify the sort variable with the package
3549 name, or rename the lexical variable.
3551 =item "my" variable %s can't be in a package
3553 (F) Lexically scoped variables aren't in a package, so it doesn't make
3554 sense to try to declare one with a package qualifier on the front. Use
3555 local() if you want to localize a package variable.
3557 =item Name "%s::%s" used only once: possible typo
3559 (W once) Typographical errors often show up as unique variable
3560 names. If you had a good reason for having a unique name, then
3561 just mention it again somehow to suppress the message. The C<our>
3562 declaration is also provided for this purpose.
3564 NOTE: This warning detects package symbols that have been used
3565 only once. This means lexical variables will never trigger this
3566 warning. It also means that all of the package variables $c, @c,
3567 %c, as well as *c, &c, sub c{}, c(), and c (the filehandle or
3568 format) are considered the same; if a program uses $c only once
3569 but also uses any of the others it will not trigger this warning.
3570 Symbols beginning with an underscore and symbols using special
3571 identifiers (q.v. L<perldata>) are exempt from this warning.
3573 =item Need exactly 3 octal digits in regex; marked by S<<-- HERE> in m/%s/
3575 (F) Within S<C<(?[ ])>>, all constants interpreted as octal need to be
3576 exactly 3 digits long. This helps catch some ambiguities. If your
3577 constant is too short, add leading zeros, like
3579 (?[ [ \078 ] ]) # Syntax error!
3580 (?[ [ \0078 ] ]) # Works
3581 (?[ [ \007 8 ] ]) # Clearer
3583 The maximum number this construct can express is C<\777>. If you
3584 need a larger one, you need to use L<\o{}|perlrebackslash/Octal escapes> instead. If you meant
3585 two separate things, you need to separate them:
3587 (?[ [ \7776 ] ]) # Syntax error!
3588 (?[ [ \o{7776} ] ]) # One meaning
3589 (?[ [ \777 6 ] ]) # Another meaning
3590 (?[ [ \777 \006 ] ]) # Still another
3592 =item Negative '/' count in unpack
3594 (F) The length count obtained from a length/code unpack operation was
3595 negative. See L<perlfunc/pack>.
3597 =item Negative length
3599 (F) You tried to do a read/write/send/recv operation with a buffer
3600 length that is less than 0. This is difficult to imagine.
3602 =item Negative offset to vec in lvalue context
3604 (F) When C<vec> is called in an lvalue context, the second argument must be
3605 greater than or equal to zero.
3607 =item Negative repeat count does nothing
3609 (W numeric) You tried to execute the
3610 L<C<x>|perlop/Multiplicative Operators> repetition operator fewer than 0
3611 times, which doesn't make sense.
3613 =item Nested quantifiers in regex; marked by S<<-- HERE> in m/%s/
3615 (F) You can't quantify a quantifier without intervening parentheses.
3616 So things like ** or +* or ?* are illegal. The S<<-- HERE> shows
3617 whereabouts in the regular expression the problem was discovered.
3619 Note that the minimal matching quantifiers, C<*?>, C<+?>, and
3620 C<??> appear to be nested quantifiers, but aren't. See L<perlre>.
3622 =item %s never introduced
3624 (S internal) The symbol in question was declared but somehow went out of
3625 scope before it could possibly have been used.
3627 =item next::method/next::can/maybe::next::method cannot find enclosing method
3629 (F) C<next::method> needs to be called within the context of a
3630 real method in a real package, and it could not find such a context.
3633 =item \N in a character class must be a named character: \N{...} in regex;
3634 marked by S<<-- HERE> in m/%s/
3636 (F) The new (as of Perl 5.12) meaning of C<\N> as C<[^\n]> is not valid in a
3637 bracketed character class, for the same reason that C<.> in a character
3638 class loses its specialness: it matches almost everything, which is
3639 probably not what you want.
3641 =item \N{} in inverted character class or as a range end-point is restricted to one character in regex; marked
3642 by S<<-- HERE> in m/%s/
3644 (F) Named Unicode character escapes (C<\N{...}>) may return a
3645 multi-character sequence. Even though a character class is
3646 supposed to match just one character of input, perl will match the
3647 whole thing correctly, except when the class is inverted (C<[^...]>),
3648 or the escape is the beginning or final end point of a range. The
3649 mathematically logical behavior for what matches when inverting
3650 is very different from what people expect, so we have decided to
3651 forbid it. Similarly unclear is what should be generated when the
3652 C<\N{...}> is used as one of the end points of the range, such as in
3654 [\x{41}-\N{ARABIC SEQUENCE YEH WITH HAMZA ABOVE WITH AE}]
3656 What is meant here is unclear, as the C<\N{...}> escape is a sequence
3657 of code points, so this is made an error.
3659 =item \N{NAME} must be resolved by the lexer in regex; marked by
3660 S<<-- HERE> in m/%s/
3662 (F) When compiling a regex pattern, an unresolved named character or
3663 sequence was encountered. This can happen in any of several ways that
3664 bypass the lexer, such as using single-quotish context, or an extra
3665 backslash in double-quotish:
3667 $re = '\N{SPACE}'; # Wrong!
3668 $re = "\\N{SPACE}"; # Wrong!
3671 Instead, use double-quotes with a single backslash:
3673 $re = "\N{SPACE}"; # ok
3676 The lexer can be bypassed as well by creating the pattern from smaller
3680 /${re}{SPACE}/; # Wrong!
3682 It's not a good idea to split a construct in the middle like this, and
3683 it doesn't work here. Instead use the solution above.
3685 Finally, the message also can happen under the C</x> regex modifier when the
3686 C<\N> is separated by spaces from the C<{>, in which case, remove the spaces.
3688 /\N {SPACE}/x; # Wrong!
3691 =item No %s allowed while running setuid
3693 (F) Certain operations are deemed to be too insecure for a setuid or
3694 setgid script to even be allowed to attempt. Generally speaking there
3695 will be another way to do what you want that is, if not secure, at least
3696 securable. See L<perlsec>.
3698 =item NO-BREAK SPACE in a charnames alias definition is deprecated
3700 (D deprecated) You defined a character name which contained a no-break
3701 space character. Change it to a regular space. Usually these names are
3702 defined in the C<:alias> import argument to C<use charnames>, but they
3703 could be defined by a translator installed into C<$^H{charnames}>. See
3704 L<charnames/CUSTOM ALIASES>.
3706 =item No code specified for -%c
3708 (F) Perl's B<-e> and B<-E> command-line options require an argument. If
3709 you want to run an empty program, pass the empty string as a separate
3710 argument or run a program consisting of a single 0 or 1:
3716 =item No comma allowed after %s
3718 (F) A list operator that has a filehandle or "indirect object" is
3719 not allowed to have a comma between that and the following arguments.
3720 Otherwise it'd be just another one of the arguments.
3722 One possible cause for this is that you expected to have imported
3723 a constant to your name space with B<use> or B<import> while no such
3724 importing took place, it may for example be that your operating
3725 system does not support that particular constant. Hopefully you did
3726 use an explicit import list for the constants you expect to see;
3727 please see L<perlfunc/use> and L<perlfunc/import>. While an
3728 explicit import list would probably have caught this error earlier
3729 it naturally does not remedy the fact that your operating system
3730 still does not support that constant. Maybe you have a typo in
3731 the constants of the symbol import list of B<use> or B<import> or in the
3732 constant name at the line where this error was triggered?
3734 =item No command into which to pipe on command line
3736 (F) An error peculiar to VMS. Perl handles its own command line
3737 redirection, and found a '|' at the end of the command line, so it
3738 doesn't know where you want to pipe the output from this command.
3740 =item No DB::DB routine defined
3742 (F) The currently executing code was compiled with the B<-d> switch, but
3743 for some reason the current debugger (e.g. F<perl5db.pl> or a C<Devel::>
3744 module) didn't define a routine to be called at the beginning of each
3747 =item No dbm on this machine
3749 (P) This is counted as an internal error, because every machine should
3750 supply dbm nowadays, because Perl comes with SDBM. See L<SDBM_File>.
3752 =item No DB::sub routine defined
3754 (F) The currently executing code was compiled with the B<-d> switch, but
3755 for some reason the current debugger (e.g. F<perl5db.pl> or a C<Devel::>
3756 module) didn't define a C<DB::sub> routine to be called at the beginning
3757 of each ordinary subroutine call.
3759 =item No directory specified for -I
3761 (F) The B<-I> command-line switch requires a directory name as part of the
3762 I<same> argument. Use B<-Ilib>, for instance. B<-I lib> won't work.
3764 =item No error file after 2> or 2>> on command line
3766 (F) An error peculiar to VMS. Perl handles its own command line
3767 redirection, and found a '2>' or a '2>>' on the command line, but can't
3768 find the name of the file to which to write data destined for stderr.
3770 =item No group ending character '%c' found in template
3772 (F) A pack or unpack template has an opening '(' or '[' without its
3773 matching counterpart. See L<perlfunc/pack>.
3775 =item No input file after < on command line
3777 (F) An error peculiar to VMS. Perl handles its own command line
3778 redirection, and found a '<' on the command line, but can't find the
3779 name of the file from which to read data for stdin.
3781 =item No next::method '%s' found for %s
3783 (F) C<next::method> found no further instances of this method name
3784 in the remaining packages of the MRO of this class. If you don't want
3785 it throwing an exception, use C<maybe::next::method>
3786 or C<next::can>. See L<mro>.
3788 =item Non-finite repeat count does nothing
3790 (W numeric) You tried to execute the
3791 L<C<x>|perlop/Multiplicative Operators> repetition operator C<Inf> (or
3792 C<-Inf>) or C<NaN> times, which doesn't make sense.
3794 =item Non-hex character in regex; marked by S<<-- HERE> in m/%s/
3796 (F) In a regular expression, there was a non-hexadecimal character where
3797 a hex one was expected, like
3802 =item Non-octal character in regex; marked by S<<-- HERE> in m/%s/
3804 (F) In a regular expression, there was a non-octal character where
3805 an octal one was expected, like
3809 =item Non-octal character '%c'. Resolved as "%s"
3811 (W digit) In parsing an octal numeric constant, a character was
3812 unexpectedly encountered that isn't octal. The resulting value
3815 =item "no" not allowed in expression
3817 (F) The "no" keyword is recognized and executed at compile time, and
3818 returns no useful value. See L<perlmod>.
3820 =item Non-string passed as bitmask
3822 (W misc) A number has been passed as a bitmask argument to select().
3823 Use the vec() function to construct the file descriptor bitmasks for
3824 select. See L<perlfunc/select>.
3826 =item No output file after > on command line
3828 (F) An error peculiar to VMS. Perl handles its own command line
3829 redirection, and found a lone '>' at the end of the command line, so it
3830 doesn't know where you wanted to redirect stdout.
3832 =item No output file after > or >> on command line
3834 (F) An error peculiar to VMS. Perl handles its own command line
3835 redirection, and found a '>' or a '>>' on the command line, but can't
3836 find the name of the file to which to write data destined for stdout.
3838 =item No package name allowed for variable %s in "our"
3840 (F) Fully qualified variable names are not allowed in "our"
3841 declarations, because that doesn't make much sense under existing
3842 semantics. Such syntax is reserved for future extensions.
3844 =item No Perl script found in input
3846 (F) You called C<perl -x>, but no line was found in the file beginning
3847 with #! and containing the word "perl".
3849 =item No setregid available
3851 (F) Configure didn't find anything resembling the setregid() call for
3854 =item No setreuid available
3856 (F) Configure didn't find anything resembling the setreuid() call for
3859 =item No such class %s
3861 (F) You provided a class qualifier in a "my", "our" or "state"
3862 declaration, but this class doesn't exist at this point in your program.
3864 =item No such class field "%s" in variable %s of type %s
3866 (F) You tried to access a key from a hash through the indicated typed
3867 variable but that key is not allowed by the package of the same type.
3868 The indicated package has restricted the set of allowed keys using the
3871 =item No such hook: %s
3873 (F) You specified a signal hook that was not recognized by Perl.
3874 Currently, Perl accepts C<__DIE__> and C<__WARN__> as valid signal hooks.
3876 =item No such pipe open
3878 (P) An error peculiar to VMS. The internal routine my_pclose() tried to
3879 close a pipe which hadn't been opened. This should have been caught
3880 earlier as an attempt to close an unopened filehandle.
3882 =item No such signal: SIG%s
3884 (W signal) You specified a signal name as a subscript to %SIG that was
3885 not recognized. Say C<kill -l> in your shell to see the valid signal
3886 names on your system.
3888 =item Not a CODE reference
3890 (F) Perl was trying to evaluate a reference to a code value (that is, a
3891 subroutine), but found a reference to something else instead. You can
3892 use the ref() function to find out what kind of ref it really was. See
3895 =item Not a GLOB reference
3897 (F) Perl was trying to evaluate a reference to a "typeglob" (that is, a
3898 symbol table entry that looks like C<*foo>), but found a reference to
3899 something else instead. You can use the ref() function to find out what
3900 kind of ref it really was. See L<perlref>.
3902 =item Not a HASH reference
3904 (F) Perl was trying to evaluate a reference to a hash value, but found a
3905 reference to something else instead. You can use the ref() function to
3906 find out what kind of ref it really was. See L<perlref>.
3908 =item Not an ARRAY reference
3910 (F) Perl was trying to evaluate a reference to an array value, but found
3911 a reference to something else instead. You can use the ref() function
3912 to find out what kind of ref it really was. See L<perlref>.
3914 =item Not an unblessed ARRAY reference
3916 (F) You passed a reference to a blessed array to C<push>, C<shift> or
3917 another array function. These only accept unblessed array references
3918 or arrays beginning explicitly with C<@>.
3920 =item Not a SCALAR reference
3922 (F) Perl was trying to evaluate a reference to a scalar value, but found
3923 a reference to something else instead. You can use the ref() function
3924 to find out what kind of ref it really was. See L<perlref>.
3926 =item Not a subroutine reference
3928 (F) Perl was trying to evaluate a reference to a code value (that is, a
3929 subroutine), but found a reference to something else instead. You can
3930 use the ref() function to find out what kind of ref it really was. See
3933 =item Not a subroutine reference in overload table
3935 (F) An attempt was made to specify an entry in an overloading table that
3936 doesn't somehow point to a valid subroutine. See L<overload>.
3938 =item Not enough arguments for %s
3940 (F) The function requires more arguments than you specified.
3942 =item Not enough format arguments
3944 (W syntax) A format specified more picture fields than the next line
3945 supplied. See L<perlform>.
3949 (A) You've accidentally run your script through the Bourne shell instead
3950 of Perl. Check the #! line, or manually feed your script into Perl
3953 =item (?[...]) not valid in locale in regex; marked by S<<-- HERE> in m/%s/
3955 (F) C<(?[...])> cannot be used within the scope of a C<S<use locale>> or with
3956 an C</l> regular expression modifier, as that would require deferring
3957 to run-time the calculation of what it should evaluate to, and it is
3958 regex compile-time only.
3960 =item no UTC offset information; assuming local time is UTC
3962 (S) A warning peculiar to VMS. Perl was unable to find the local
3963 timezone offset, so it's assuming that local system time is equivalent
3964 to UTC. If it's not, define the logical name
3965 F<SYS$TIMEZONE_DIFFERENTIAL> to translate to the number of seconds which
3966 need to be added to UTC to get local time.
3968 =item NULL OP IN RUN
3970 (S debugging) Some internal routine called run() with a null opcode
3973 =item Null picture in formline
3975 (F) The first argument to formline must be a valid format picture
3976 specification. It was found to be empty, which probably means you
3977 supplied it an uninitialized value. See L<perlform>.
3981 (P) An attempt was made to realloc NULL.
3983 =item NULL regexp argument
3985 (P) The internal pattern matching routines blew it big time.
3987 =item NULL regexp parameter
3989 (P) The internal pattern matching routines are out of their gourd.
3991 =item Number too long
3993 (F) Perl limits the representation of decimal numbers in programs to
3994 about 250 characters. You've exceeded that length. Future
3995 versions of Perl are likely to eliminate this arbitrary limitation. In
3996 the meantime, try using scientific notation (e.g. "1e6" instead of
3999 =item Number with no digits
4001 (F) Perl was looking for a number but found nothing that looked like
4002 a number. This happens, for example with C<\o{}>, with no number between
4005 =item Octal number > 037777777777 non-portable
4007 (W portable) The octal number you specified is larger than 2**32-1
4008 (4294967295) and therefore non-portable between systems. See
4009 L<perlport> for more on portability concerns.
4011 =item Odd name/value argument for subroutine
4013 (F) A subroutine using a slurpy hash parameter in its signature
4014 received an odd number of arguments to populate the hash. It requires
4015 the arguments to be paired, with the same number of keys as values.
4016 The caller of the subroutine is presumably at fault. Inconveniently,
4017 this error will be reported at the location of the subroutine, not that
4020 =item Odd number of arguments for overload::constant
4022 (W overload) The call to overload::constant contained an odd number of
4023 arguments. The arguments should come in pairs.
4025 =item Odd number of elements in anonymous hash
4027 (W misc) You specified an odd number of elements to initialize a hash,
4028 which is odd, because hashes come in key/value pairs.
4030 =item Odd number of elements in hash assignment
4032 (W misc) You specified an odd number of elements to initialize a hash,
4033 which is odd, because hashes come in key/value pairs.
4035 =item Offset outside string
4037 (F)(W layer) You tried to do a read/write/send/recv/seek operation
4038 with an offset pointing outside the buffer. This is difficult to
4039 imagine. The sole exceptions to this are that zero padding will
4040 take place when going past the end of the string when either
4041 C<sysread()>ing a file, or when seeking past the end of a scalar opened
4042 for I/O (in anticipation of future reads and to imitate the behavior
4045 =item %s() on unopened %s
4047 (W unopened) An I/O operation was attempted on a filehandle that was
4048 never initialized. You need to do an open(), a sysopen(), or a socket()
4049 call, or call a constructor from the FileHandle package.
4051 =item -%s on unopened filehandle %s
4053 (W unopened) You tried to invoke a file test operator on a filehandle
4054 that isn't open. Check your control flow. See also L<perlfunc/-X>.
4058 (S internal) An internal warning that the grammar is screwed up.
4062 (S internal) An internal warning that the grammar is screwed up.
4064 =item Opening dirhandle %s also as a file
4066 (D io, deprecated) You used open() to associate a filehandle to
4067 a symbol (glob or scalar) that already holds a dirhandle.
4068 Although legal, this idiom might render your code confusing
4071 =item Opening filehandle %s also as a directory
4073 (D io, deprecated) You used opendir() to associate a dirhandle to
4074 a symbol (glob or scalar) that already holds a filehandle.
4075 Although legal, this idiom might render your code confusing
4078 =item Operand with no preceding operator in regex; marked by S<<-- HERE> in
4081 (F) You wrote something like
4083 (?[ \p{Digit} \p{Thai} ])
4085 There are two operands, but no operator giving how you want to combine
4088 =item Operation "%s": no method found, %s
4090 (F) An attempt was made to perform an overloaded operation for which no
4091 handler was defined. While some handlers can be autogenerated in terms
4092 of other handlers, there is no default handler for any operation, unless
4093 the C<fallback> overloading key is specified to be true. See L<overload>.
4095 =item Operation "%s" returns its argument for non-Unicode code point 0x%X
4097 (S non_unicode) You performed an operation requiring Unicode semantics
4098 on a code point that is not in Unicode, so what it should do is not
4099 defined. Perl has chosen to have it do nothing, and warn you.
4101 If the operation shown is "ToFold", it means that case-insensitive
4102 matching in a regular expression was done on the code point.
4104 If you know what you are doing you can turn off this warning by
4105 C<no warnings 'non_unicode';>.
4107 =item Operation "%s" returns its argument for UTF-16 surrogate U+%X
4109 (S surrogate) You performed an operation requiring Unicode
4110 semantics on a Unicode surrogate. Unicode frowns upon the use
4111 of surrogates for anything but storing strings in UTF-16, but
4112 semantics are (reluctantly) defined for the surrogates, and
4113 they are to do nothing for this operation. Because the use of
4114 surrogates can be dangerous, Perl warns.
4116 If the operation shown is "ToFold", it means that case-insensitive
4117 matching in a regular expression was done on the code point.
4119 If you know what you are doing you can turn off this warning by
4120 C<no warnings 'surrogate';>.
4122 =item Operator or semicolon missing before %s
4124 (S ambiguous) You used a variable or subroutine call where the parser
4125 was expecting an operator. The parser has assumed you really meant to
4126 use an operator, but this is highly likely to be incorrect. For
4127 example, if you say "*foo *foo" it will be interpreted as if you said
4130 =item Optional parameter lacks default expression
4132 (F) In a subroutine signature, you wrote something like "$a =", making a
4133 named optional parameter without a default value. A nameless optional
4134 parameter is permitted to have no default value, but a named one must
4135 have a specific default. You probably want "$a = undef".
4137 =item "our" variable %s redeclared
4139 (W misc) You seem to have already declared the same global once before
4140 in the current lexical scope.
4142 =item Out of memory!
4144 (X) The malloc() function returned 0, indicating there was insufficient
4145 remaining memory (or virtual memory) to satisfy the request. Perl has
4146 no option but to exit immediately.
4148 At least in Unix you may be able to get past this by increasing your
4149 process datasize limits: in csh/tcsh use C<limit> and
4150 C<limit datasize n> (where C<n> is the number of kilobytes) to check
4151 the current limits and change them, and in ksh/bash/zsh use C<ulimit -a>
4152 and C<ulimit -d n>, respectively.
4154 =item Out of memory during %s extend
4156 (X) An attempt was made to extend an array, a list, or a string beyond
4157 the largest possible memory allocation.
4159 =item Out of memory during "large" request for %s
4161 (F) The malloc() function returned 0, indicating there was insufficient
4162 remaining memory (or virtual memory) to satisfy the request. However,
4163 the request was judged large enough (compile-time default is 64K), so a
4164 possibility to shut down by trapping this error is granted.
4166 =item Out of memory during request for %s
4168 (X)(F) The malloc() function returned 0, indicating there was
4169 insufficient remaining memory (or virtual memory) to satisfy the
4172 The request was judged to be small, so the possibility to trap it
4173 depends on the way perl was compiled. By default it is not trappable.
4174 However, if compiled for this, Perl may use the contents of C<$^M> as an
4175 emergency pool after die()ing with this message. In this case the error
4176 is trappable I<once>, and the error message will include the line and file
4177 where the failed request happened.
4179 =item Out of memory during ridiculously large request
4181 (F) You can't allocate more than 2^31+"small amount" bytes. This error
4182 is most likely to be caused by a typo in the Perl program. e.g.,
4183 C<$arr[time]> instead of C<$arr[$time]>.
4185 =item Out of memory for yacc stack
4187 (F) The yacc parser wanted to grow its stack so it could continue
4188 parsing, but realloc() wouldn't give it more memory, virtual or
4191 =item '.' outside of string in pack
4193 (F) The argument to a '.' in your template tried to move the working
4194 position to before the start of the packed string being built.
4196 =item '@' outside of string in unpack
4198 (F) You had a template that specified an absolute position outside
4199 the string being unpacked. See L<perlfunc/pack>.
4201 =item '@' outside of string with malformed UTF-8 in unpack
4203 (F) You had a template that specified an absolute position outside
4204 the string being unpacked. The string being unpacked was also invalid
4205 UTF-8. See L<perlfunc/pack>.
4207 =item overload arg '%s' is invalid
4209 (W overload) The L<overload> pragma was passed an argument it did not
4210 recognize. Did you mistype an operator?
4212 =item Overloaded dereference did not return a reference
4214 (F) An object with an overloaded dereference operator was dereferenced,
4215 but the overloaded operation did not return a reference. See
4218 =item Overloaded qr did not return a REGEXP
4220 (F) An object with a C<qr> overload was used as part of a match, but the
4221 overloaded operation didn't return a compiled regexp. See L<overload>.
4223 =item %s package attribute may clash with future reserved word: %s
4225 (W reserved) A lowercase attribute name was used that had a
4226 package-specific handler. That name might have a meaning to Perl itself
4227 some day, even though it doesn't yet. Perhaps you should use a
4228 mixed-case attribute name, instead. See L<attributes>.
4230 =item pack/unpack repeat count overflow
4232 (F) You can't specify a repeat count so large that it overflows your
4233 signed integers. See L<perlfunc/pack>.
4237 (W io) A single call to write() produced more lines than can fit on a
4238 page. See L<perlform>.
4242 (P) An internal error.
4244 =item panic: attempt to call %s in %s
4246 (P) One of the file test operators entered a code branch that calls
4247 an ACL related-function, but that function is not available on this
4248 platform. Earlier checks mean that it should not be possible to
4249 enter this branch on this platform.
4251 =item panic: child pseudo-process was never scheduled
4253 (P) A child pseudo-process in the ithreads implementation on Windows
4254 was not scheduled within the time period allowed and therefore was not
4255 able to initialize properly.
4257 =item panic: ck_grep, type=%u
4259 (P) Failed an internal consistency check trying to compile a grep.
4261 =item panic: ck_split, type=%u
4263 (P) Failed an internal consistency check trying to compile a split.
4265 =item panic: corrupt saved stack index %ld
4267 (P) The savestack was requested to restore more localized values than
4268 there are in the savestack.
4270 =item panic: del_backref
4272 (P) Failed an internal consistency check while trying to reset a weak
4277 (P) We popped the context stack to an eval context, and then discovered
4278 it wasn't an eval context.
4280 =item panic: do_subst
4282 (P) The internal pp_subst() routine was called with invalid operational
4285 =item panic: do_trans_%s
4287 (P) The internal do_trans routines were called with invalid operational
4290 =item panic: fold_constants JMPENV_PUSH returned %d
4292 (P) While attempting folding constants an exception other than an C<eval>
4295 =item panic: frexp: %f
4297 (P) The library function frexp() failed, making printf("%f") impossible.
4299 =item panic: goto, type=%u, ix=%ld
4301 (P) We popped the context stack to a context with the specified label,
4302 and then discovered it wasn't a context we know how to do a goto in.
4304 =item panic: gp_free failed to free glob pointer
4306 (P) The internal routine used to clear a typeglob's entries tried
4307 repeatedly, but each time something re-created entries in the glob.
4308 Most likely the glob contains an object with a reference back to
4309 the glob and a destructor that adds a new object to the glob.
4311 =item panic: INTERPCASEMOD, %s
4313 (P) The lexer got into a bad state at a case modifier.
4315 =item panic: INTERPCONCAT, %s
4317 (P) The lexer got into a bad state parsing a string with brackets.
4319 =item panic: kid popen errno read
4321 (F) A forked child returned an incomprehensible message about its errno.
4323 =item panic: last, type=%u
4325 (P) We popped the context stack to a block context, and then discovered
4326 it wasn't a block context.
4328 =item panic: leave_scope clearsv
4330 (P) A writable lexical variable became read-only somehow within the
4333 =item panic: leave_scope inconsistency %u
4335 (P) The savestack probably got out of sync. At least, there was an
4336 invalid enum on the top of it.
4338 =item panic: magic_killbackrefs
4340 (P) Failed an internal consistency check while trying to reset all weak
4341 references to an object.
4343 =item panic: malloc, %s
4345 (P) Something requested a negative number of bytes of malloc.
4347 =item panic: memory wrap
4349 (P) Something tried to allocate either more memory than possible or a
4352 =item panic: pad_alloc, %p!=%p
4354 (P) The compiler got confused about which scratch pad it was allocating
4355 and freeing temporaries and lexicals from.
4357 =item panic: pad_free curpad, %p!=%p
4359 (P) The compiler got confused about which scratch pad it was allocating
4360 and freeing temporaries and lexicals from.
4362 =item panic: pad_free po
4364 (P) A zero scratch pad offset was detected internally. An attempt was
4365 made to free a target that had not been allocated to begin with.
4367 =item panic: pad_reset curpad, %p!=%p
4369 (P) The compiler got confused about which scratch pad it was allocating
4370 and freeing temporaries and lexicals from.
4372 =item panic: pad_sv po
4374 (P) A zero scratch pad offset was detected internally. Most likely
4375 an operator needed a target but that target had not been allocated
4376 for whatever reason.
4378 =item panic: pad_swipe curpad, %p!=%p
4380 (P) The compiler got confused about which scratch pad it was allocating
4381 and freeing temporaries and lexicals from.
4383 =item panic: pad_swipe po
4385 (P) An invalid scratch pad offset was detected internally.
4387 =item panic: pp_iter, type=%u
4389 (P) The foreach iterator got called in a non-loop context frame.
4391 =item panic: pp_match%s
4393 (P) The internal pp_match() routine was called with invalid operational
4396 =item panic: pp_split, pm=%p, s=%p
4398 (P) Something terrible went wrong in setting up for the split.
4400 =item panic: realloc, %s
4402 (P) Something requested a negative number of bytes of realloc.
4404 =item panic: reference miscount on nsv in sv_replace() (%d != 1)
4406 (P) The internal sv_replace() function was handed a new SV with a
4407 reference count other than 1.
4409 =item panic: restartop in %s
4411 (P) Some internal routine requested a goto (or something like it), and
4412 didn't supply the destination.
4414 =item panic: return, type=%u
4416 (P) We popped the context stack to a subroutine or eval context, and
4417 then discovered it wasn't a subroutine or eval context.
4419 =item panic: scan_num, %s
4421 (P) scan_num() got called on something that wasn't a number.
4423 =item panic: Sequence (?{...}): no code block found in regex m/%s/
4425 (P) While compiling a pattern that has embedded (?{}) or (??{}) code
4426 blocks, perl couldn't locate the code block that should have already been
4427 seen and compiled by perl before control passed to the regex compiler.
4429 =item panic: strxfrm() gets absurd - a => %u, ab => %u
4431 (P) The interpreter's sanity check of the C function strxfrm() failed.
4432 In your current locale the returned transformation of the string "ab"
4433 is shorter than that of the string "a", which makes no sense.
4435 =item panic: sv_chop %s
4437 (P) The sv_chop() routine was passed a position that is not within the
4438 scalar's string buffer.
4440 =item panic: sv_insert, midend=%p, bigend=%p
4442 (P) The sv_insert() routine was told to remove more string than there
4445 =item panic: top_env
4447 (P) The compiler attempted to do a goto, or something weird like that.
4449 =item panic: unimplemented op %s (#%d) called
4451 (P) The compiler is screwed up and attempted to use an op that isn't
4452 permitted at run time.
4454 =item panic: utf16_to_utf8: odd bytelen
4456 (P) Something tried to call utf16_to_utf8 with an odd (as opposed
4457 to even) byte length.
4459 =item panic: utf16_to_utf8_reversed: odd bytelen
4461 (P) Something tried to call utf16_to_utf8_reversed with an odd (as opposed
4462 to even) byte length.
4464 =item panic: yylex, %s
4466 (P) The lexer got into a bad state while processing a case modifier.
4468 =item Parentheses missing around "%s" list
4470 (W parenthesis) You said something like
4476 my ($foo, $bar) = @_;
4478 Remember that "my", "our", "local" and "state" bind tighter than comma.
4480 =item Parsing code internal error (%s)
4482 (F) Parsing code supplied by an extension violated the parser's API in
4485 =item Passing malformed UTF-8 to "%s" is deprecated
4487 (D deprecated, utf8) This message indicates a bug either in the Perl
4488 core or in XS code. Such code was trying to find out if a character,
4489 allegedly stored internally encoded as UTF-8, was of a given type, such
4490 as being punctuation or a digit. But the character was not encoded in
4491 legal UTF-8. The C<%s> is replaced by a string that can be used by
4492 knowledgeable people to determine what the type being checked against
4493 was. If C<utf8> warnings are enabled, a further message is raised,
4494 giving details of the malformation.
4496 =item Pattern subroutine nesting without pos change exceeded limit in regex
4498 (F) You used a pattern that uses too many nested subpattern calls without
4499 consuming any text. Restructure the pattern so text is consumed before
4500 the nesting limit is exceeded.
4502 =item C<-p> destination: %s
4504 (F) An error occurred during the implicit output invoked by the C<-p>
4505 command-line switch. (This output goes to STDOUT unless you've
4506 redirected it with select().)
4508 =item Perl API version %s of %s does not match %s
4510 (F) The XS module in question was compiled against a different incompatible
4511 version of Perl than the one that has loaded the XS module.
4513 =item Perl folding rules are not up-to-date for 0x%X; please use the perlbug
4514 utility to report; in regex; marked by S<<-- HERE> in m/%s/
4516 (S regexp) You used a regular expression with case-insensitive matching,
4517 and there is a bug in Perl in which the built-in regular expression
4518 folding rules are not accurate. This may lead to incorrect results.
4519 Please report this as a bug using the L<perlbug> utility.
4521 =item PerlIO layer ':win32' is experimental
4523 (S experimental::win32_perlio) The C<:win32> PerlIO layer is
4524 experimental. If you want to take the risk of using this layer,
4525 simply disable this warning:
4527 no warnings "experimental::win32_perlio";
4529 =item Perl_my_%s() not available
4531 (F) Your platform has very uncommon byte-order and integer size,
4532 so it was not possible to set up some or all fixed-width byte-order
4533 conversion functions. This is only a problem when you're using the
4534 '<' or '>' modifiers in (un)pack templates. See L<perlfunc/pack>.
4536 =item Perl %s required (did you mean %s?)--this is only %s, stopped
4538 (F) The code you are trying to run has asked for a newer version of
4539 Perl than you are running. Perhaps C<use 5.10> was written instead
4540 of C<use 5.010> or C<use v5.10>. Without the leading C<v>, the number is
4541 interpreted as a decimal, with every three digits after the
4542 decimal point representing a part of the version number. So 5.10
4543 is equivalent to v5.100.
4545 =item Perl %s required--this is only %s, stopped
4547 (F) The module in question uses features of a version of Perl more
4548 recent than the currently running version. How long has it been since
4549 you upgraded, anyway? See L<perlfunc/require>.
4551 =item PERL_SH_DIR too long
4553 (F) An error peculiar to OS/2. PERL_SH_DIR is the directory to find the
4554 C<sh>-shell in. See "PERL_SH_DIR" in L<perlos2>.
4556 =item PERL_SIGNALS illegal: "%s"
4558 (X) See L<perlrun/PERL_SIGNALS> for legal values.
4560 =item Perls since %s too modern--this is %s, stopped
4562 (F) The code you are trying to run claims it will not run
4563 on the version of Perl you are using because it is too new.
4564 Maybe the code needs to be updated, or maybe it is simply
4565 wrong and the version check should just be removed.
4567 =item perl: warning: Non hex character in '$ENV{PERL_HASH_SEED}', seed only partially set
4569 (S) PERL_HASH_SEED should match /^\s*(?:0x)?[0-9a-fA-F]+\s*\z/ but it
4570 contained a non hex character. This could mean you are not using the
4571 hash seed you think you are.
4573 =item perl: warning: Setting locale failed.
4575 (S) The whole warning message will look something like:
4577 perl: warning: Setting locale failed.
4578 perl: warning: Please check that your locale settings:
4581 are supported and installed on your system.
4582 perl: warning: Falling back to the standard locale ("C").
4584 Exactly what were the failed locale settings varies. In the above the
4585 settings were that the LC_ALL was "En_US" and the LANG had no value.
4586 This error means that Perl detected that you and/or your operating
4587 system supplier and/or system administrator have set up the so-called
4588 locale system but Perl could not use those settings. This was not
4589 dead serious, fortunately: there is a "default locale" called "C" that
4590 Perl can and will use, and the script will be run. Before you really
4591 fix the problem, however, you will get the same error message each
4592 time you run Perl. How to really fix the problem can be found in
4593 L<perllocale> section B<LOCALE PROBLEMS>.
4595 =item perl: warning: strange setting in '$ENV{PERL_PERTURB_KEYS}': '%s'
4597 (S) Perl was run with the environment variable PERL_PERTURB_KEYS defined
4598 but containing an unexpected value. The legal values of this setting
4601 Numeric | String | Result
4602 --------+---------------+-----------------------------------------
4603 0 | NO | Disables key traversal randomization
4604 1 | RANDOM | Enables full key traversal randomization
4605 2 | DETERMINISTIC | Enables repeatable key traversal
4608 Both numeric and string values are accepted, but note that string values are
4609 case sensitive. The default for this setting is "RANDOM" or 1.
4611 =item pid %x not a child
4613 (W exec) A warning peculiar to VMS. Waitpid() was asked to wait for a
4614 process which isn't a subprocess of the current process. While this is
4615 fine from VMS' perspective, it's probably not what you intended.
4617 =item 'P' must have an explicit size in unpack
4619 (F) The unpack format P must have an explicit size, not "*".
4621 =item pop on reference is experimental
4623 (S experimental::autoderef) C<pop> with a scalar argument is experimental
4624 and may change or be removed in a future Perl version. If you want to
4625 take the risk of using this feature, simply disable this warning:
4627 no warnings "experimental::autoderef";
4629 =item POSIX class [:%s:] unknown in regex; marked by S<< <-- HERE in m/%s/ >>
4631 (F) The class in the character class [: :] syntax is unknown. The S<<-- HERE>
4632 shows whereabouts in the regular expression the problem was discovered.
4633 Note that the POSIX character classes do B<not> have the C<is> prefix
4634 the corresponding C interfaces have: in other words, it's C<[[:print:]]>,
4635 not C<isprint>. See L<perlre>.
4637 =item POSIX getpgrp can't take an argument
4639 (F) Your system has POSIX getpgrp(), which takes no argument, unlike
4640 the BSD version, which takes a pid.
4642 =item POSIX syntax [%c %c] belongs inside character classes in regex; marked by
4643 S<<-- HERE> in m/%s/
4645 (W regexp) The character class constructs [: :], [= =], and [. .] go
4646 I<inside> character classes, the [] are part of the construct, for example:
4647 /[012[:alpha:]345]/. Note that [= =] and [. .] are not currently
4648 implemented; they are simply placeholders for future extensions and
4649 will cause fatal errors. The S<<-- HERE> shows whereabouts in the regular
4650 expression the problem was discovered. See L<perlre>.
4652 =item POSIX syntax [. .] is reserved for future extensions in regex; marked by
4653 S<<-- HERE> in m/%s/
4655 (F) Within regular expression character classes ([]) the syntax beginning
4656 with "[." and ending with ".]" is reserved for future extensions. If you
4657 need to represent those character sequences inside a regular expression
4658 character class, just quote the square brackets with the backslash: "\[."
4659 and ".\]". The S<<-- HERE> shows whereabouts in the regular expression the
4660 problem was discovered. See L<perlre>.
4662 =item POSIX syntax [= =] is reserved for future extensions in regex; marked by
4663 S<<-- HERE> in m/%s/
4665 (F) Within regular expression character classes ([]) the syntax beginning
4666 with "[=" and ending with "=]" is reserved for future extensions. If you
4667 need to represent those character sequences inside a regular expression
4668 character class, just quote the square brackets with the backslash: "\[="
4669 and "=\]". The S<<-- HERE> shows whereabouts in the regular expression the
4670 problem was discovered. See L<perlre>.
4672 =item Possible attempt to put comments in qw() list
4674 (W qw) qw() lists contain items separated by whitespace; as with literal
4675 strings, comment characters are not ignored, but are instead treated as
4676 literal data. (You may have used different delimiters than the
4677 parentheses shown here; braces are also frequently used.)
4679 You probably wrote something like this:
4686 when you should have written this:
4693 If you really want comments, build your list the
4694 old-fashioned way, with quotes and commas:
4698 'b', # another comment
4701 =item Possible attempt to separate words with commas
4703 (W qw) qw() lists contain items separated by whitespace; therefore
4704 commas aren't needed to separate the items. (You may have used
4705 different delimiters than the parentheses shown here; braces are also
4708 You probably wrote something like this:
4712 which puts literal commas into some of the list items. Write it without
4713 commas if you don't want them to appear in your data:
4717 =item Possible memory corruption: %s overflowed 3rd argument
4719 (F) An ioctl() or fcntl() returned more than Perl was bargaining for.
4720 Perl guesses a reasonable buffer size, but puts a sentinel byte at the
4721 end of the buffer just in case. This sentinel byte got clobbered, and
4722 Perl assumes that memory is now corrupted. See L<perlfunc/ioctl>.
4724 =item Possible precedence issue with control flow operator
4726 (W syntax) There is a possible problem with the mixing of a control
4727 flow operator (e.g. C<return>) and a low-precedence operator like
4730 sub { return $a or $b; }
4734 sub { (return $a) or $b; }
4736 Which is effectively just:
4740 Either use parentheses or the high-precedence variant of the operator.
4742 Note this may be also triggered for constructs like:
4746 =item Possible precedence problem on bitwise %c operator
4748 (W precedence) Your program uses a bitwise logical operator in conjunction
4749 with a numeric comparison operator, like this :
4751 if ($x & $y == 0) { ... }
4753 This expression is actually equivalent to C<$x & ($y == 0)>, due to the
4754 higher precedence of C<==>. This is probably not what you want. (If you
4755 really meant to write this, disable the warning, or, better, put the
4756 parentheses explicitly and write C<$x & ($y == 0)>).
4758 =item Possible unintended interpolation of $\ in regex
4760 (W ambiguous) You said something like C<m/$\/> in a regex.
4761 The regex C<m/foo$\s+bar/m> translates to: match the word 'foo', the output
4762 record separator (see L<perlvar/$\>) and the letter 's' (one time or more)
4763 followed by the word 'bar'.
4765 If this is what you intended then you can silence the warning by using
4766 C<m/${\}/> (for example: C<m/foo${\}s+bar/>).
4768 If instead you intended to match the word 'foo' at the end of the line
4769 followed by whitespace and the word 'bar' on the next line then you can use
4770 C<m/$(?)\/> (for example: C<m/foo$(?)\s+bar/>).
4772 =item Possible unintended interpolation of %s in string
4774 (W ambiguous) You said something like '@foo' in a double-quoted string
4775 but there was no array C<@foo> in scope at the time. If you wanted a
4776 literal @foo, then write it as \@foo; otherwise find out what happened
4777 to the array you apparently lost track of.
4779 =item Postfix dereference is experimental
4781 (S experimental::postderef) This warning is emitted if you use
4782 the experimental postfix dereference syntax. Simply suppress the
4783 warning if you want to use the feature, but know that in doing
4784 so you are taking the risk of using an experimental feature which
4785 may change or be removed in a future Perl version:
4787 no warnings "experimental::postderef";
4788 use feature "postderef", "postderef_qq";
4794 =item Precedence problem: open %s should be open(%s)
4796 (S precedence) The old irregular construct
4800 is now misinterpreted as
4804 because of the strict regularization of Perl 5's grammar into unary and
4805 list operators. (The old open was a little of both.) You must put
4806 parentheses around the filehandle, or use the new "or" operator instead
4809 =item Premature end of script headers
4813 =item printf() on closed filehandle %s
4815 (W closed) The filehandle you're writing to got itself closed sometime
4816 before now. Check your control flow.
4818 =item print() on closed filehandle %s
4820 (W closed) The filehandle you're printing on got itself closed sometime
4821 before now. Check your control flow.
4823 =item Process terminated by SIG%s
4825 (W) This is a standard message issued by OS/2 applications, while *nix
4826 applications die in silence. It is considered a feature of the OS/2
4827 port. One can easily disable this by appropriate sighandlers, see
4828 L<perlipc/"Signals">. See also "Process terminated by SIGTERM/SIGINT"
4831 =item Property '%s' is unknown in regex; marked by S<<-- HERE> in m/%s/
4833 (F) The named property which you specified via C<\p> or C<\P> is not one
4834 known to Perl. Perhaps you misspelled the name? See
4835 L<perluniprops/Properties accessible through \p{} and \P{}>
4836 for a complete list of available official
4837 properties. If it is a L<user-defined property|perlunicode/User-Defined Character Properties>
4838 it must have been defined by the time the regular expression is
4841 =item Prototype after '%c' for %s : %s
4843 (W illegalproto) A character follows % or @ in a prototype. This is
4844 useless, since % and @ gobble the rest of the subroutine arguments.
4846 =item Prototype mismatch: %s vs %s
4848 (S prototype) The subroutine being declared or defined had previously been
4849 declared or defined with a different function prototype.
4851 =item Prototype not terminated
4853 (F) You've omitted the closing parenthesis in a function prototype
4856 =item Prototype '%s' overridden by attribute 'prototype(%s)' in %s
4858 (W prototype) A prototype was declared in both the parentheses after
4859 the sub name and via the prototype attribute. The prototype in
4860 parentheses is useless, since it will be replaced by the prototype
4861 from the attribute before it's ever used.
4863 =item push on reference is experimental
4865 (S experimental::autoderef) C<push> with a scalar argument is experimental
4866 and may change or be removed in a future Perl version. If you want to
4867 take the risk of using this feature, simply disable this warning:
4869 no warnings "experimental::autoderef";
4871 =item Quantifier follows nothing in regex; marked by S<< <-- HERE in m/%s/ >>
4873 (F) You started a regular expression with a quantifier. Backslash it if
4874 you meant it literally. The S<<-- HERE> shows whereabouts in the regular
4875 expression the problem was discovered. See L<perlre>.
4877 =item Quantifier in {,} bigger than %d in regex; marked by S<<-- HERE> in
4880 (F) There is currently a limit to the size of the min and max values of
4881 the {min,max} construct. The S<<-- HERE> shows whereabouts in the regular
4882 expression the problem was discovered. See L<perlre>.
4884 =item Quantifier {n,m} with n > m can't match in regex
4886 =item Quantifier {n,m} with n > m can't match in regex; marked by
4887 S<<-- HERE> in m/%s/
4889 (W regexp) Minima should be less than or equal to maxima. If you really
4890 want your regexp to match something 0 times, just put {0}.
4892 =item Quantifier unexpected on zero-length expression in regex m/%s/
4894 (W regexp) You applied a regular expression quantifier in a place where
4895 it makes no sense, such as on a zero-width assertion. Try putting the
4896 quantifier inside the assertion instead. For example, the way to match
4897 "abc" provided that it is followed by three repetitions of "xyz" is
4898 C</abc(?=(?:xyz){3})/>, not C</abc(?=xyz){3}/>.
4900 =item Range iterator outside integer range
4902 (F) One (or both) of the numeric arguments to the range operator ".."
4903 are outside the range which can be represented by integers internally.
4904 One possible workaround is to force Perl to use magical string increment
4905 by prepending "0" to your numbers.
4907 =item readdir() attempted on invalid dirhandle %s
4909 (W io) The dirhandle you're reading from is either closed or not really
4910 a dirhandle. Check your control flow.
4912 =item readline() on closed filehandle %s
4914 (W closed) The filehandle you're reading from got itself closed sometime
4915 before now. Check your control flow.
4917 =item read() on closed filehandle %s
4919 (W closed) You tried to read from a closed filehandle.
4921 =item read() on unopened filehandle %s
4923 (W unopened) You tried to read from a filehandle that was never opened.
4925 =item Reallocation too large: %x
4927 (F) You can't allocate more than 64K on an MS-DOS machine.
4929 =item realloc() of freed memory ignored
4931 (S malloc) An internal routine called realloc() on something that had
4934 =item Recompile perl with B<-D>DEBUGGING to use B<-D> switch
4936 (S debugging) You can't use the B<-D> option unless the code to produce
4937 the desired output is compiled into Perl, which entails some overhead,
4938 which is why it's currently left out of your copy.
4940 =item Recursive call to Perl_load_module in PerlIO_find_layer
4942 (P) It is currently not permitted to load modules when creating
4943 a filehandle inside an %INC hook. This can happen with C<open my
4944 $fh, '<', \$scalar>, which implicitly loads PerlIO::scalar. Try
4945 loading PerlIO::scalar explicitly first.
4947 =item Recursive inheritance detected in package '%s'
4949 (F) While calculating the method resolution order (MRO) of a package, Perl
4950 believes it found an infinite loop in the C<@ISA> hierarchy. This is a
4951 crude check that bails out after 100 levels of C<@ISA> depth.
4953 =item Redundant argument in %s
4955 (W redundant) You called a function with more arguments than other
4956 arguments you supplied indicated would be needed. Currently only
4957 emitted when a printf-type format required fewer arguments than were
4958 supplied, but might be used in the future for e.g. L<perlfunc/pack>.
4960 =item refcnt_dec: fd %d%s
4962 =item refcnt: fd %d%s
4964 =item refcnt_inc: fd %d%s
4966 (P) Perl's I/O implementation failed an internal consistency check. If
4967 you see this message, something is very wrong.
4969 =item Reference found where even-sized list expected
4971 (W misc) You gave a single reference where Perl was expecting a list
4972 with an even number of elements (for assignment to a hash). This
4973 usually means that you used the anon hash constructor when you meant
4974 to use parens. In any case, a hash requires key/value B<pairs>.
4976 %hash = { one => 1, two => 2, }; # WRONG
4977 %hash = [ qw/ an anon array / ]; # WRONG
4978 %hash = ( one => 1, two => 2, ); # right
4979 %hash = qw( one 1 two 2 ); # also fine
4981 =item Reference is already weak
4983 (W misc) You have attempted to weaken a reference that is already weak.
4984 Doing so has no effect.
4986 =item Reference to invalid group 0 in regex; marked by S<<-- HERE> in m/%s/
4988 (F) You used C<\g0> or similar in a regular expression. You may refer
4989 to capturing parentheses only with strictly positive integers
4990 (normal backreferences) or with strictly negative integers (relative
4991 backreferences). Using 0 does not make sense.
4993 =item Reference to nonexistent group in regex; marked by S<<-- HERE> in
4996 (F) You used something like C<\7> in your regular expression, but there are
4997 not at least seven sets of capturing parentheses in the expression. If
4998 you wanted to have the character with ordinal 7 inserted into the regular
4999 expression, prepend zeroes to make it three digits long: C<\007>
5001 The <-- HERE shows whereabouts in the regular expression the problem was
5004 =item Reference to nonexistent named group in regex; marked by S<<-- HERE>
5007 (F) You used something like C<\k'NAME'> or C<< \k<NAME> >> in your regular
5008 expression, but there is no corresponding named capturing parentheses
5009 such as C<(?'NAME'...)> or C<< (?<NAME>...) >>. Check if the name has been
5010 spelled correctly both in the backreference and the declaration.
5012 The <-- HERE shows whereabouts in the regular expression the problem was
5015 =item Reference to nonexistent or unclosed group in regex; marked by
5016 S<<-- HERE> in m/%s/
5018 (F) You used something like C<\g{-7}> in your regular expression, but there
5019 are not at least seven sets of closed capturing parentheses in the
5020 expression before where the C<\g{-7}> was located.
5022 The <-- HERE shows whereabouts in the regular expression the problem was
5025 =item regexp memory corruption
5027 (P) The regular expression engine got confused by what the regular
5028 expression compiler gave it.
5030 =item Regexp modifier "/%c" may appear a maximum of twice
5032 =item Regexp modifier "%c" may appear a maximum of twice in regex; marked
5033 by S<<-- HERE> in m/%s/
5035 (F) The regular expression pattern had too many occurrences
5036 of the specified modifier. Remove the extraneous ones.
5038 =item Regexp modifier "%c" may not appear after the "-" in regex; marked by <--
5041 (F) Turning off the given modifier has the side effect of turning on
5042 another one. Perl currently doesn't allow this. Reword the regular
5043 expression to use the modifier you want to turn on (and place it before
5044 the minus), instead of the one you want to turn off.
5046 =item Regexp modifier "/%c" may not appear twice
5048 =item Regexp modifier "%c" may not appear twice in regex; marked by <--
5051 (F) The regular expression pattern had too many occurrences
5052 of the specified modifier. Remove the extraneous ones.
5054 =item Regexp modifiers "/%c" and "/%c" are mutually exclusive
5056 =item Regexp modifiers "%c" and "%c" are mutually exclusive in regex;
5057 marked by S<<-- HERE> in m/%s/
5059 (F) The regular expression pattern had more than one of these
5060 mutually exclusive modifiers. Retain only the modifier that is
5061 supposed to be there.
5063 =item Regexp out of space in regex m/%s/
5065 (P) A "can't happen" error, because safemalloc() should have caught it
5068 =item Repeated format line will never terminate (~~ and @#)
5070 (F) Your format contains the ~~ repeat-until-blank sequence and a
5071 numeric field that will never go blank so that the repetition never
5072 terminates. You might use ^# instead. See L<perlform>.
5074 =item Replacement list is longer than search list
5076 (W misc) You have used a replacement list that is longer than the
5077 search list. So the additional elements in the replacement list
5080 =item '%s' resolved to '\o{%s}%d'
5082 (W misc, regexp) You wrote something like C<\08>, or C<\179> in a
5083 double-quotish string. All but the last digit is treated as a single
5084 character, specified in octal. The last digit is the next character in
5085 the string. To tell Perl that this is indeed what you want, you can use
5086 the C<\o{ }> syntax, or use exactly three digits to specify the octal
5089 =item Reversed %s= operator
5091 (W syntax) You wrote your assignment operator backwards. The = must
5092 always come last, to avoid ambiguity with subsequent unary operators.
5094 =item rewinddir() attempted on invalid dirhandle %s
5096 (W io) The dirhandle you tried to do a rewinddir() on is either closed
5097 or not really a dirhandle. Check your control flow.
5099 =item Scalars leaked: %d
5101 (S internal) Something went wrong in Perl's internal bookkeeping
5102 of scalars: not all scalar variables were deallocated by the time
5103 Perl exited. What this usually indicates is a memory leak, which
5104 is of course bad, especially if the Perl program is intended to be
5107 =item Scalar value @%s[%s] better written as $%s[%s]
5109 (W syntax) You've used an array slice (indicated by @) to select a
5110 single element of an array. Generally it's better to ask for a scalar
5111 value (indicated by $). The difference is that C<$foo[&bar]> always
5112 behaves like a scalar, both when assigning to it and when evaluating its
5113 argument, while C<@foo[&bar]> behaves like a list when you assign to it,
5114 and provides a list context to its subscript, which can do weird things
5115 if you're expecting only one subscript.
5117 On the other hand, if you were actually hoping to treat the array
5118 element as a list, you need to look into how references work, because
5119 Perl will not magically convert between scalars and lists for you. See
5122 =item Scalar value @%s{%s} better written as $%s{%s}
5124 (W syntax) You've used a hash slice (indicated by @) to select a single
5125 element of a hash. Generally it's better to ask for a scalar value
5126 (indicated by $). The difference is that C<$foo{&bar}> always behaves
5127 like a scalar, both when assigning to it and when evaluating its
5128 argument, while C<@foo{&bar}> behaves like a list when you assign to it,
5129 and provides a list context to its subscript, which can do weird things
5130 if you're expecting only one subscript.
5132 On the other hand, if you were actually hoping to treat the hash element
5133 as a list, you need to look into how references work, because Perl will
5134 not magically convert between scalars and lists for you. See
5137 =item Search pattern not terminated
5139 (F) The lexer couldn't find the final delimiter of a // or m{}
5140 construct. Remember that bracketing delimiters count nesting level.
5141 Missing the leading C<$> from a variable C<$m> may cause this error.
5143 Note that since Perl 5.10.0 a // can also be the I<defined-or>
5144 construct, not just the empty search pattern. Therefore code written
5145 in Perl 5.10.0 or later that uses the // as the I<defined-or> can be
5146 misparsed by pre-5.10.0 Perls as a non-terminated search pattern.
5148 =item seekdir() attempted on invalid dirhandle %s
5150 (W io) The dirhandle you are doing a seekdir() on is either closed or not
5151 really a dirhandle. Check your control flow.
5153 =item %sseek() on unopened filehandle
5155 (W unopened) You tried to use the seek() or sysseek() function on a
5156 filehandle that was either never opened or has since been closed.
5158 =item select not implemented
5160 (F) This machine doesn't implement the select() system call.
5162 =item Self-ties of arrays and hashes are not supported
5164 (F) Self-ties are of arrays and hashes are not supported in
5165 the current implementation.
5167 =item Semicolon seems to be missing
5169 (W semicolon) A nearby syntax error was probably caused by a missing
5170 semicolon, or possibly some other missing operator, such as a comma.
5172 =item semi-panic: attempt to dup freed string
5174 (S internal) The internal newSVsv() routine was called to duplicate a
5175 scalar that had previously been marked as free.
5177 =item sem%s not implemented
5179 (F) You don't have System V semaphore IPC on your system.
5181 =item send() on closed socket %s
5183 (W closed) The socket you're sending to got itself closed sometime
5184 before now. Check your control flow.
5186 =item Sequence "\c{" invalid
5188 (F) These three characters may not appear in sequence in a
5189 double-quotish context. This message is raised only on non-ASCII
5190 platforms (a different error message is output on ASCII ones). If you
5191 were intending to specify a control character with this sequence, you'll
5192 have to use a different way to specify it.
5194 =item Sequence (? incomplete in regex; marked by S<<-- HERE> in m/%s/
5196 (F) A regular expression ended with an incomplete extension (?. The
5197 S<<-- HERE> shows whereabouts in the regular expression the problem was
5198 discovered. See L<perlre>.
5200 =item Sequence (?%c...) not implemented in regex; marked by S<<-- HERE> in
5203 (F) A proposed regular expression extension has the character reserved
5204 but has not yet been written. The S<<-- HERE> shows whereabouts in the
5205 regular expression the problem was discovered. See L<perlre>.
5207 =item Sequence (?%s...) not recognized in regex; marked by S<<-- HERE> in
5210 (F) You used a regular expression extension that doesn't make sense.
5211 The S<<-- HERE> shows whereabouts in the regular expression the problem was
5212 discovered. This may happen when using the C<(?^...)> construct to tell
5213 Perl to use the default regular expression modifiers, and you
5214 redundantly specify a default modifier. For other
5215 causes, see L<perlre>.
5217 =item Sequence (?#... not terminated in regex m/%s/
5219 (F) A regular expression comment must be terminated by a closing
5220 parenthesis. Embedded parentheses aren't allowed. See
5223 =item Sequence (?&... not terminated in regex; marked by S<<-- HERE> in
5226 (F) A named reference of the form C<(?&...)> was missing the final
5227 closing parenthesis after the name. The S<<-- HERE> shows whereabouts
5228 in the regular expression the problem was discovered.
5230 =item Sequence (?%c... not terminated in regex; marked by S<<-- HERE>
5233 (F) A named group of the form C<(?'...')> or C<< (?<...>) >> was missing the final
5234 closing quote or angle bracket. The S<<-- HERE> shows whereabouts in the
5235 regular expression the problem was discovered.
5237 =item Sequence (?(%c... not terminated in regex; marked by S<<-- HERE>
5240 (F) A named reference of the form C<(?('...')...)> or C<< (?(<...>)...) >> was
5241 missing the final closing quote or angle bracket after the name. The
5242 S<<-- HERE> shows whereabouts in the regular expression the problem was
5245 =item Sequence \%s... not terminated in regex; marked by S<<-- HERE> in
5248 (F) The regular expression expects a mandatory argument following the escape
5249 sequence and this has been omitted or incorrectly written.
5251 =item Sequence (?{...}) not terminated with ')'
5253 (F) The end of the perl code contained within the {...} must be
5254 followed immediately by a ')'.
5256 =item Sequence ?P=... not terminated in regex; marked by S<<-- HERE> in
5259 (F) A named reference of the form C<(?P=...)> was missing the final
5260 closing parenthesis after the name. The S<<-- HERE> shows whereabouts
5261 in the regular expression the problem was discovered.
5263 =item Sequence (?R) not terminated in regex m/%s/
5265 (F) An C<(?R)> or C<(?0)> sequence in a regular expression was missing the
5268 =item Server error (a.k.a. "500 Server error")
5270 (A) This is the error message generally seen in a browser window
5271 when trying to run a CGI program (including SSI) over the web. The
5272 actual error text varies widely from server to server. The most
5273 frequently-seen variants are "500 Server error", "Method (something)
5274 not permitted", "Document contains no data", "Premature end of script
5275 headers", and "Did not produce a valid header".
5277 B<This is a CGI error, not a Perl error>.
5279 You need to make sure your script is executable, is accessible by
5280 the user CGI is running the script under (which is probably not the
5281 user account you tested it under), does not rely on any environment
5282 variables (like PATH) from the user it isn't running under, and isn't
5283 in a location where the CGI server can't find it, basically, more or
5284 less. Please see the following for more information:
5286 http://www.perl.org/CGI_MetaFAQ.html
5287 http://www.htmlhelp.org/faq/cgifaq.html
5288 http://www.w3.org/Security/Faq/
5290 You should also look at L<perlfaq9>.
5292 =item setegid() not implemented
5294 (F) You tried to assign to C<$)>, and your operating system doesn't
5295 support the setegid() system call (or equivalent), or at least Configure
5298 =item seteuid() not implemented
5300 (F) You tried to assign to C<< $> >>, and your operating system doesn't
5301 support the seteuid() system call (or equivalent), or at least Configure
5304 =item setpgrp can't take arguments
5306 (F) Your system has the setpgrp() from BSD 4.2, which takes no
5307 arguments, unlike POSIX setpgid(), which takes a process ID and process
5310 =item setrgid() not implemented
5312 (F) You tried to assign to C<$(>, and your operating system doesn't
5313 support the setrgid() system call (or equivalent), or at least Configure
5316 =item setruid() not implemented
5318 (F) You tried to assign to C<$<>, and your operating system doesn't
5319 support the setruid() system call (or equivalent), or at least Configure
5322 =item setsockopt() on closed socket %s
5324 (W closed) You tried to set a socket option on a closed socket. Did you
5325 forget to check the return value of your socket() call? See
5326 L<perlfunc/setsockopt>.
5328 =item Setting ${^ENCODING} is deprecated
5330 (D deprecated) You assigned a non-C<undef> value to C<${^ENCODING}>.
5331 This is deprecated; see C<L<perlvar/${^ENCODING}>> for details.
5333 =item Setting $/ to a reference to %s as a form of slurp is deprecated, treating as undef
5335 (D deprecated) You assigned a reference to a scalar to C<$/> where the
5336 referenced item is not a positive integer. In older perls this B<appeared>
5337 to work the same as setting it to C<undef> but was in fact internally
5338 different, less efficient and with very bad luck could have resulted in
5339 your file being split by a stringified form of the reference.
5341 In Perl 5.20.0 this was changed so that it would be B<exactly> the same as
5342 setting C<$/> to undef, with the exception that this warning would be
5345 You are recommended to change your code to set C<$/> to C<undef> explicitly
5346 if you wish to slurp the file. In future versions of Perl assigning
5347 a reference to will throw a fatal error.
5349 =item Setting $/ to %s reference is forbidden
5351 (F) You tried to assign a reference to a non integer to C<$/>. In older
5352 Perls this would have behaved similarly to setting it to a reference to
5353 a positive integer, where the integer was the address of the reference.
5354 As of Perl 5.20.0 this is a fatal error, to allow future versions of Perl
5355 to use non-integer refs for more interesting purposes.
5357 =item shift on reference is experimental
5359 (S experimental::autoderef) C<shift> with a scalar argument is experimental
5360 and may change or be removed in a future Perl version. If you want to
5361 take the risk of using this feature, simply disable this warning:
5363 no warnings "experimental::autoderef";
5365 =item shm%s not implemented
5367 (F) You don't have System V shared memory IPC on your system.
5369 =item !=~ should be !~
5371 (W syntax) The non-matching operator is !~, not !=~. !=~ will be
5372 interpreted as the != (numeric not equal) and ~ (1's complement)
5373 operators: probably not what you intended.
5375 =item /%s/ should probably be written as "%s"
5377 (W syntax) You have used a pattern where Perl expected to find a string,
5378 as in the first argument to C<join>. Perl will treat the true or false
5379 result of matching the pattern against $_ as the string, which is
5380 probably not what you had in mind.
5382 =item shutdown() on closed socket %s
5384 (W closed) You tried to do a shutdown on a closed socket. Seems a bit
5387 =item SIG%s handler "%s" not defined
5389 (W signal) The signal handler named in %SIG doesn't, in fact, exist.
5390 Perhaps you put it into the wrong package?
5392 =item Slab leaked from cv %p
5394 (S) If you see this message, then something is seriously wrong with the
5395 internal bookkeeping of op trees. An op tree needed to be freed after
5396 a compilation error, but could not be found, so it was leaked instead.
5398 =item sleep(%u) too large
5400 (W overflow) You called C<sleep> with a number that was larger than
5401 it can reliably handle and C<sleep> probably slept for less time than
5404 =item Slurpy parameter not last
5406 (F) In a subroutine signature, you put something after a slurpy (array or
5407 hash) parameter. The slurpy parameter takes all the available arguments,
5408 so there can't be any left to fill later parameters.
5410 =item Smart matching a non-overloaded object breaks encapsulation
5412 (F) You should not use the C<~~> operator on an object that does not
5413 overload it: Perl refuses to use the object's underlying structure
5414 for the smart match.
5416 =item Smartmatch is experimental
5418 (S experimental::smartmatch) This warning is emitted if you
5419 use the smartmatch (C<~~>) operator. This is currently an experimental
5420 feature, and its details are subject to change in future releases of
5421 Perl. Particularly, its current behavior is noticed for being
5422 unnecessarily complex and unintuitive, and is very likely to be
5425 =item sort is now a reserved word
5427 (F) An ancient error message that almost nobody ever runs into anymore.
5428 But before sort was a keyword, people sometimes used it as a filehandle.
5430 =item Sort subroutine didn't return single value
5432 (F) A sort comparison subroutine written in XS must return exactly one
5433 item. See L<perlfunc/sort>.
5435 =item Source filters apply only to byte streams
5437 (F) You tried to activate a source filter (usually by loading a
5438 source filter module) within a string passed to C<eval>. This is
5439 not permitted under the C<unicode_eval> feature. Consider using
5440 C<evalbytes> instead. See L<feature>.
5442 =item splice() offset past end of array
5444 (W misc) You attempted to specify an offset that was past the end of
5445 the array passed to splice(). Splicing will instead commence at the
5446 end of the array, rather than past it. If this isn't what you want,
5447 try explicitly pre-extending the array by assigning $#array = $offset.
5448 See L<perlfunc/splice>.
5450 =item splice on reference is experimental
5452 (S experimental::autoderef) C<splice> with a scalar argument
5453 is experimental and may change or be removed in a future
5454 Perl version. If you want to take the risk of using this
5455 feature, simply disable this warning:
5457 no warnings "experimental::autoderef";
5461 (P) The split was looping infinitely. (Obviously, a split shouldn't
5462 iterate more times than there are characters of input, which is what
5463 happened.) See L<perlfunc/split>.
5465 =item Statement unlikely to be reached
5467 (W exec) You did an exec() with some statement after it other than a
5468 die(). This is almost always an error, because exec() never returns
5469 unless there was a failure. You probably wanted to use system()
5470 instead, which does return. To suppress this warning, put the exec() in
5473 =item "state" subroutine %s can't be in a package
5475 (F) Lexically scoped subroutines aren't in a package, so it doesn't make
5476 sense to try to declare one with a package qualifier on the front.
5478 =item "state %s" used in sort comparison
5480 (W syntax) The package variables $a and $b are used for sort comparisons.
5481 You used $a or $b in as an operand to the C<< <=> >> or C<cmp> operator inside a
5482 sort comparison block, and the variable had earlier been declared as a
5483 lexical variable. Either qualify the sort variable with the package
5484 name, or rename the lexical variable.
5486 =item "state" variable %s can't be in a package
5488 (F) Lexically scoped variables aren't in a package, so it doesn't make
5489 sense to try to declare one with a package qualifier on the front. Use
5490 local() if you want to localize a package variable.
5492 =item stat() on unopened filehandle %s
5494 (W unopened) You tried to use the stat() function on a filehandle that
5495 was either never opened or has since been closed.
5497 =item Strings with code points over 0xFF may not be mapped into in-memory file handles
5499 (W utf8) You tried to open a reference to a scalar for read or append
5500 where the scalar contained code points over 0xFF. In-memory files
5501 model on-disk files and can only contain bytes.
5503 =item Stub found while resolving method "%s" overloading "%s" in package "%s"
5505 (P) Overloading resolution over @ISA tree may be broken by importation
5506 stubs. Stubs should never be implicitly created, but explicit calls to
5507 C<can> may break this.
5509 =item Subroutine "&%s" is not available
5511 (W closure) During compilation, an inner named subroutine or eval is
5512 attempting to capture an outer lexical subroutine that is not currently
5513 available. This can happen for one of two reasons. First, the lexical
5514 subroutine may be declared in an outer anonymous subroutine that has
5515 not yet been created. (Remember that named subs are created at compile
5516 time, while anonymous subs are created at run-time.) For example,
5518 sub { my sub a {...} sub f { \&a } }
5520 At the time that f is created, it can't capture the current "a" sub,
5521 since the anonymous subroutine hasn't been created yet. Conversely, the
5522 following won't give a warning since the anonymous subroutine has by now
5523 been created and is live:
5525 sub { my sub a {...} eval 'sub f { \&a }' }->();
5527 The second situation is caused by an eval accessing a lexical subroutine
5528 that has gone out of scope, for example,
5536 Here, when the '\&a' in the eval is being compiled, f() is not currently
5537 being executed, so its &a is not available for capture.
5539 =item "%s" subroutine &%s masks earlier declaration in same %s
5541 (W misc) A "my" or "state" subroutine has been redeclared in the
5542 current scope or statement, effectively eliminating all access to
5543 the previous instance. This is almost always a typographical error.
5544 Note that the earlier subroutine will still exist until the end of
5545 the scope or until all closure references to it are destroyed.
5547 =item Subroutine %s redefined
5549 (W redefine) You redefined a subroutine. To suppress this warning, say
5552 no warnings 'redefine';
5553 eval "sub name { ... }";
5556 =item Subroutine "%s" will not stay shared
5558 (W closure) An inner (nested) I<named> subroutine is referencing a "my"
5559 subroutine defined in an outer named subroutine.
5561 When the inner subroutine is called, it will see the value of the outer
5562 subroutine's lexical subroutine as it was before and during the *first*
5563 call to the outer subroutine; in this case, after the first call to the
5564 outer subroutine is complete, the inner and outer subroutines will no
5565 longer share a common value for the lexical subroutine. In other words,
5566 it will no longer be shared. This will especially make a difference
5567 if the lexical subroutines accesses lexical variables declared in its
5570 This problem can usually be solved by making the inner subroutine
5571 anonymous, using the C<sub {}> syntax. When inner anonymous subs that
5572 reference lexical subroutines in outer subroutines are created, they
5573 are automatically rebound to the current values of such lexical subs.
5575 =item Substitution loop
5577 (P) The substitution was looping infinitely. (Obviously, a substitution
5578 shouldn't iterate more times than there are characters of input, which
5579 is what happened.) See the discussion of substitution in
5580 L<perlop/"Regexp Quote-Like Operators">.
5582 =item Substitution pattern not terminated
5584 (F) The lexer couldn't find the interior delimiter of an s/// or s{}{}
5585 construct. Remember that bracketing delimiters count nesting level.
5586 Missing the leading C<$> from variable C<$s> may cause this error.
5588 =item Substitution replacement not terminated
5590 (F) The lexer couldn't find the final delimiter of an s/// or s{}{}
5591 construct. Remember that bracketing delimiters count nesting level.
5592 Missing the leading C<$> from variable C<$s> may cause this error.
5594 =item substr outside of string
5596 (W substr)(F) You tried to reference a substr() that pointed outside of
5597 a string. That is, the absolute value of the offset was larger than the
5598 length of the string. See L<perlfunc/substr>. This warning is fatal if
5599 substr is used in an lvalue context (as the left hand side of an
5600 assignment or as a subroutine argument for example).
5602 =item sv_upgrade from type %d down to type %d
5604 (P) Perl tried to force the upgrade of an SV to a type which was actually
5605 inferior to its current type.
5607 =item SWASHNEW didn't return an HV ref
5609 (P) Something went wrong internally when Perl was trying to look up
5612 =item Switch (?(condition)... contains too many branches in regex; marked by
5613 S<<-- HERE> in m/%s/
5615 (F) A (?(condition)if-clause|else-clause) construct can have at most
5616 two branches (the if-clause and the else-clause). If you want one or
5617 both to contain alternation, such as using C<this|that|other>, enclose
5618 it in clustering parentheses:
5620 (?(condition)(?:this|that|other)|else-clause)
5622 The S<<-- HERE> shows whereabouts in the regular expression the problem
5623 was discovered. See L<perlre>.
5625 =item Switch condition not recognized in regex; marked by S<<-- HERE> in
5628 (F) The condition part of a (?(condition)if-clause|else-clause) construct
5629 is not known. The condition must be one of the following:
5631 (1) (2) ... true if 1st, 2nd, etc., capture matched
5632 (<NAME>) ('NAME') true if named capture matched
5633 (?=...) (?<=...) true if subpattern matches
5634 (?!...) (?<!...) true if subpattern fails to match
5635 (?{ CODE }) true if code returns a true value
5636 (R) true if evaluating inside recursion
5637 (R1) (R2) ... true if directly inside capture group 1, 2, etc.
5638 (R&NAME) true if directly inside named capture
5639 (DEFINE) always false; for defining named subpatterns
5641 The <-- HERE shows whereabouts in the regular expression the problem was
5642 discovered. See L<perlre>.
5644 =item Switch (?(condition)... not terminated in regex; marked by
5645 S<<-- HERE> in m/%s/
5647 (F) You omitted to close a (?(condition)...) block somewhere
5648 in the pattern. Add a closing parenthesis in the appropriate
5649 position. See L<perlre>.
5651 =item switching effective %s is not implemented
5653 (F) While under the C<use filetest> pragma, we cannot switch the real
5654 and effective uids or gids.
5658 (F) Probably means you had a syntax error. Common reasons include:
5660 A keyword is misspelled.
5661 A semicolon is missing.
5663 An opening or closing parenthesis is missing.
5664 An opening or closing brace is missing.
5665 A closing quote is missing.
5667 Often there will be another error message associated with the syntax
5668 error giving more information. (Sometimes it helps to turn on B<-w>.)
5669 The error message itself often tells you where it was in the line when
5670 it decided to give up. Sometimes the actual error is several tokens
5671 before this, because Perl is good at understanding random input.
5672 Occasionally the line number may be misleading, and once in a blue moon
5673 the only way to figure out what's triggering the error is to call
5674 C<perl -c> repeatedly, chopping away half the program each time to see
5675 if the error went away. Sort of the cybernetic version of S<20 questions>.
5677 =item syntax error at line %d: '%s' unexpected
5679 (A) You've accidentally run your script through the Bourne shell instead
5680 of Perl. Check the #! line, or manually feed your script into Perl
5683 =item syntax error in file %s at line %d, next 2 tokens "%s"
5685 (F) This error is likely to occur if you run a perl5 script through
5686 a perl4 interpreter, especially if the next 2 tokens are "use strict"
5687 or "my $var" or "our $var".
5689 =item Syntax error in (?[...]) in regex m/%s/
5691 (F) Perl could not figure out what you meant inside this construct; this
5692 notifies you that it is giving up trying.
5696 (F) The final summary message when a C<perl -c> succeeds.
5698 =item sysread() on closed filehandle %s
5700 (W closed) You tried to read from a closed filehandle.
5702 =item sysread() on unopened filehandle %s
5704 (W unopened) You tried to read from a filehandle that was never opened.
5706 =item System V %s is not implemented on this machine
5708 (F) You tried to do something with a function beginning with "sem",
5709 "shm", or "msg" but that System V IPC is not implemented in your
5710 machine. In some machines the functionality can exist but be
5711 unconfigured. Consult your system support.
5713 =item syswrite() on closed filehandle %s
5715 (W closed) The filehandle you're writing to got itself closed sometime
5716 before now. Check your control flow.
5718 =item C<-T> and C<-B> not implemented on filehandles
5720 (F) Perl can't peek at the stdio buffer of filehandles when it doesn't
5721 know about your kind of stdio. You'll have to use a filename instead.
5723 =item Target of goto is too deeply nested
5725 (F) You tried to use C<goto> to reach a label that was too deeply nested
5726 for Perl to reach. Perl is doing you a favor by refusing.
5728 =item telldir() attempted on invalid dirhandle %s
5730 (W io) The dirhandle you tried to telldir() is either closed or not really
5731 a dirhandle. Check your control flow.
5733 =item tell() on unopened filehandle
5735 (W unopened) You tried to use the tell() function on a filehandle that
5736 was either never opened or has since been closed.
5738 =item That use of $[ is unsupported
5740 (F) Assignment to C<$[> is now strictly circumscribed, and interpreted
5741 as a compiler directive. You may say only one of
5750 This is to prevent the problem of one module changing the array base out
5751 from under another module inadvertently. See L<perlvar/$[> and L<arybase>.
5753 =item The crypt() function is unimplemented due to excessive paranoia.
5755 (F) Configure couldn't find the crypt() function on your machine,
5756 probably because your vendor didn't supply it, probably because they
5757 think the U.S. Government thinks it's a secret, or at least that they
5758 will continue to pretend that it is. And if you quote me on that, I
5761 =item The %s function is unimplemented
5763 (F) The function indicated isn't implemented on this architecture,
5764 according to the probings of Configure.
5766 =item The lexical_subs feature is experimental
5768 (S experimental::lexical_subs) This warning is emitted if you
5769 declare a sub with C<my> or C<state>. Simply suppress the warning
5770 if you want to use the feature, but know that in doing so you
5771 are taking the risk of using an experimental feature which may
5772 change or be removed in a future Perl version:
5774 no warnings "experimental::lexical_subs";
5775 use feature "lexical_subs";
5778 =item The regex_sets feature is experimental
5780 (S experimental::regex_sets) This warning is emitted if you
5781 use the syntax S<C<(?[ ])>> in a regular expression.
5782 The details of this feature are subject to change.
5783 if you want to use it, but know that in doing so you
5784 are taking the risk of using an experimental feature which may
5785 change in a future Perl version, you can do this to silence the
5788 no warnings "experimental::regex_sets";
5790 =item The signatures feature is experimental
5792 (S experimental::signatures) This warning is emitted if you unwrap a
5793 subroutine's arguments using a signature. Simply suppress the warning
5794 if you want to use the feature, but know that in doing so you are taking
5795 the risk of using an experimental feature which may change or be removed
5796 in a future Perl version:
5798 no warnings "experimental::signatures";
5799 use feature "signatures";
5800 sub foo ($left, $right) { ... }
5802 =item The stat preceding %s wasn't an lstat
5804 (F) It makes no sense to test the current stat buffer for symbolic
5805 linkhood if the last stat that wrote to the stat buffer already went
5806 past the symlink to get to the real file. Use an actual filename
5809 =item The 'unique' attribute may only be applied to 'our' variables
5811 (F) This attribute was never supported on C<my> or C<sub> declarations.
5813 =item This Perl can't reset CRTL environ elements (%s)
5815 =item This Perl can't set CRTL environ elements (%s=%s)
5817 (W internal) Warnings peculiar to VMS. You tried to change or delete an
5818 element of the CRTL's internal environ array, but your copy of Perl
5819 wasn't built with a CRTL that contained the setenv() function. You'll
5820 need to rebuild Perl with a CRTL that does, or redefine
5821 F<PERL_ENV_TABLES> (see L<perlvms>) so that the environ array isn't the
5822 target of the change to
5823 %ENV which produced the warning.
5825 =item This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().
5827 (F) Something has attempted to use an internal API call which
5828 depends on Perl being compiled with the default support for randomized hash
5829 key traversal, but this Perl has been compiled without it. You should
5830 report this warning to the relevant upstream party, or recompile perl
5831 with default options.
5833 =item times not implemented
5835 (F) Your version of the C library apparently doesn't do times(). I
5836 suspect you're not running on Unix.
5838 =item "-T" is on the #! line, it must also be used on the command line
5840 (X) The #! line (or local equivalent) in a Perl script contains
5841 the B<-T> option (or the B<-t> option), but Perl was not invoked with
5842 B<-T> in its command line. This is an error because, by the time
5843 Perl discovers a B<-T> in a script, it's too late to properly taint
5844 everything from the environment. So Perl gives up.
5846 If the Perl script is being executed as a command using the #!
5847 mechanism (or its local equivalent), this error can usually be
5848 fixed by editing the #! line so that the B<-%c> option is a part of
5849 Perl's first argument: e.g. change C<perl -n -%c> to C<perl -%c -n>.
5851 If the Perl script is being executed as C<perl scriptname>, then the
5852 B<-%c> option must appear on the command line: C<perl -%c scriptname>.
5854 =item To%s: illegal mapping '%s'
5856 (F) You tried to define a customized To-mapping for lc(), lcfirst,
5857 uc(), or ucfirst() (or their string-inlined versions), but you
5858 specified an illegal mapping.
5859 See L<perlunicode/"User-Defined Character Properties">.
5861 =item Too deeply nested ()-groups
5863 (F) Your template contains ()-groups with a ridiculously deep nesting level.
5865 =item Too few args to syscall
5867 (F) There has to be at least one argument to syscall() to specify the
5868 system call to call, silly dilly.
5870 =item Too few arguments for subroutine
5872 (F) A subroutine using a signature received fewer arguments than required
5873 by the signature. The caller of the subroutine is presumably at fault.
5874 Inconveniently, this error will be reported at the location of the
5875 subroutine, not that of the caller.
5877 =item Too late for "-%s" option
5879 (X) The #! line (or local equivalent) in a Perl script contains the
5880 B<-M>, B<-m> or B<-C> option.
5882 In the case of B<-M> and B<-m>, this is an error because those options
5883 are not intended for use inside scripts. Use the C<use> pragma instead.
5885 The B<-C> option only works if it is specified on the command line as
5886 well (with the same sequence of letters or numbers following). Either
5887 specify this option on the command line, or, if your system supports
5888 it, make your script executable and run it directly instead of passing
5891 =item Too late to run %s block
5893 (W void) A CHECK or INIT block is being defined during run time proper,
5894 when the opportunity to run them has already passed. Perhaps you are
5895 loading a file with C<require> or C<do> when you should be using C<use>
5896 instead. Or perhaps you should put the C<require> or C<do> inside a
5899 =item Too many args to syscall
5901 (F) Perl supports a maximum of only 14 args to syscall().
5903 =item Too many arguments for %s
5905 (F) The function requires fewer arguments than you specified.
5907 =item Too many arguments for subroutine
5909 (F) A subroutine using a signature received more arguments than required
5910 by the signature. The caller of the subroutine is presumably at fault.
5911 Inconveniently, this error will be reported at the location of the
5912 subroutine, not that of the caller.
5916 (A) You've accidentally run your script through B<csh> instead of Perl.
5917 Check the #! line, or manually feed your script into Perl yourself.
5921 (A) You've accidentally run your script through B<csh> instead of Perl.
5922 Check the #! line, or manually feed your script into Perl yourself.
5924 =item Trailing \ in regex m/%s/
5926 (F) The regular expression ends with an unbackslashed backslash.
5927 Backslash it. See L<perlre>.
5929 =item Transliteration pattern not terminated
5931 (F) The lexer couldn't find the interior delimiter of a tr/// or tr[][]
5932 or y/// or y[][] construct. Missing the leading C<$> from variables
5933 C<$tr> or C<$y> may cause this error.
5935 =item Transliteration replacement not terminated
5937 (F) The lexer couldn't find the final delimiter of a tr///, tr[][],
5938 y/// or y[][] construct.
5940 =item '%s' trapped by operation mask
5942 (F) You tried to use an operator from a Safe compartment in which it's
5943 disallowed. See L<Safe>.
5945 =item truncate not implemented
5947 (F) Your machine doesn't implement a file truncation mechanism that
5948 Configure knows about.
5950 =item Type of arg %d to &CORE::%s must be %s
5952 (F) The subroutine in question in the CORE package requires its argument
5953 to be a hard reference to data of the specified type. Overloading is
5954 ignored, so a reference to an object that is not the specified type, but
5955 nonetheless has overloading to handle it, will still not be accepted.
5957 =item Type of arg %d to %s must be %s (not %s)
5959 (F) This function requires the argument in that position to be of a
5960 certain type. Arrays must be @NAME or C<@{EXPR}>. Hashes must be
5961 %NAME or C<%{EXPR}>. No implicit dereferencing is allowed--use the
5962 {EXPR} forms as an explicit dereference. See L<perlref>.
5964 =item Type of argument to %s must be unblessed hashref or arrayref
5966 (F) You called C<keys>, C<values> or C<each> with a scalar argument that
5967 was not a reference to an unblessed hash or array.
5969 =item umask not implemented
5971 (F) Your machine doesn't implement the umask function and you tried to
5972 use it to restrict permissions for yourself (EXPR & 0700).
5974 =item Unbalanced context: %d more PUSHes than POPs
5976 (S internal) The exit code detected an internal inconsistency in how
5977 many execution contexts were entered and left.
5979 =item Unbalanced saves: %d more saves than restores
5981 (S internal) The exit code detected an internal inconsistency in how
5982 many values were temporarily localized.
5984 =item Unbalanced scopes: %d more ENTERs than LEAVEs
5986 (S internal) The exit code detected an internal inconsistency in how
5987 many blocks were entered and left.
5989 =item Unbalanced string table refcount: (%d) for "%s"
5991 (S internal) On exit, Perl found some strings remaining in the shared
5992 string table used for copy on write and for hash keys. The entries
5993 should have been freed, so this indicates a bug somewhere.
5995 =item Unbalanced tmps: %d more allocs than frees
5997 (S internal) The exit code detected an internal inconsistency in how
5998 many mortal scalars were allocated and freed.
6000 =item Undefined format "%s" called
6002 (F) The format indicated doesn't seem to exist. Perhaps it's really in
6003 another package? See L<perlform>.
6005 =item Undefined sort subroutine "%s" called
6007 (F) The sort comparison routine specified doesn't seem to exist.
6008 Perhaps it's in a different package? See L<perlfunc/sort>.
6010 =item Undefined subroutine &%s called
6012 (F) The subroutine indicated hasn't been defined, or if it was, it has
6013 since been undefined.
6015 =item Undefined subroutine called
6017 (F) The anonymous subroutine you're trying to call hasn't been defined,
6018 or if it was, it has since been undefined.
6020 =item Undefined subroutine in sort
6022 (F) The sort comparison routine specified is declared but doesn't seem
6023 to have been defined yet. See L<perlfunc/sort>.
6025 =item Undefined top format "%s" called
6027 (F) The format indicated doesn't seem to exist. Perhaps it's really in
6028 another package? See L<perlform>.
6030 =item Undefined value assigned to typeglob
6032 (W misc) An undefined value was assigned to a typeglob, a la
6033 C<*foo = undef>. This does nothing. It's possible that you really mean
6036 =item %s: Undefined variable
6038 (A) You've accidentally run your script through B<csh> instead of Perl.
6039 Check the #! line, or manually feed your script into Perl yourself.
6041 =item Unescaped left brace in regex is deprecated, passed through in regex;
6042 marked by <-- HERE in m/%s/
6044 (D deprecated, regexp) You used a literal C<"{"> character in a regular
6045 expression pattern. You should change to use C<"\{"> instead, because a
6046 future version of Perl (tentatively v5.26) will consider this to be a
6047 syntax error. If the pattern delimiters are also braces, any matching
6048 right brace (C<"}">) should also be escaped to avoid confusing the parser,
6053 =item unexec of %s into %s failed!
6055 (F) The unexec() routine failed for some reason. See your local FSF
6056 representative, who probably put it there in the first place.
6058 =item Unexpected binary operator '%c' with no preceding operand in regex;
6059 marked by S<<-- HERE> in m/%s/
6061 (F) You had something like this:
6065 where the C<"|"> is a binary operator with an operand on the right, but
6066 no operand on the left.
6068 =item Unexpected character in regex; marked by S<<-- HERE> in m/%s/
6070 (F) You had something like this:
6074 Within C<(?[ ])>, no literal characters are allowed unless they are
6075 within an inner pair of square brackets, like
6079 Another possibility is that you forgot a backslash. Perl isn't smart
6080 enough to figure out what you really meant.
6082 =item Unexpected constant lvalue entersub entry via type/targ %d:%d
6084 (P) When compiling a subroutine call in lvalue context, Perl failed an
6085 internal consistency check. It encountered a malformed op tree.
6087 =item Unexpected exit %u
6089 (S) exit() was called or the script otherwise finished gracefully when
6090 C<PERL_EXIT_WARN> was set in C<PL_exit_flags>.
6092 =item Unexpected exit failure %d
6094 (S) An uncaught die() was called when C<PERL_EXIT_WARN> was set in
6097 =item Unexpected ')' in regex; marked by S<<-- HERE> in m/%s/
6099 (F) You had something like this:
6101 (?[ ( \p{Digit} + ) ])
6103 The C<")"> is out-of-place. Something apparently was supposed to
6104 be combined with the digits, or the C<"+"> shouldn't be there, or
6105 something like that. Perl can't figure out what was intended.
6107 =item Unexpected '(' with no preceding operator in regex; marked by
6108 S<<-- HERE> in m/%s/
6110 (F) You had something like this:
6112 (?[ \p{Digit} ( \p{Lao} + \p{Thai} ) ])
6114 There should be an operator before the C<"(">, as there's
6115 no indication as to how the digits are to be combined
6116 with the characters in the Lao and Thai scripts.
6118 =item Unicode non-character U+%X is illegal for open interchange
6120 (S nonchar) Certain codepoints, such as U+FFFE and U+FFFF, are
6121 defined by the Unicode standard to be non-characters. Those
6122 are legal codepoints, but are reserved for internal use; so,
6123 applications shouldn't attempt to exchange them. An application
6124 may not be expecting any of these characters at all, and receiving
6125 them may lead to bugs. If you know what you are doing you can
6126 turn off this warning by C<no warnings 'nonchar';>.
6128 This is not really a "severe" error, but it is supposed to be
6129 raised by default even if warnings are not enabled, and currently
6130 the only way to do that in Perl is to mark it as serious.
6132 =item Unicode surrogate U+%X is illegal in UTF-8
6134 (S surrogate) You had a UTF-16 surrogate in a context where they are
6135 not considered acceptable. These code points, between U+D800 and
6136 U+DFFF (inclusive), are used by Unicode only for UTF-16. However, Perl
6137 internally allows all unsigned integer code points (up to the size limit
6138 available on your platform), including surrogates. But these can cause
6139 problems when being input or output, which is likely where this message
6140 came from. If you really really know what you are doing you can turn
6141 off this warning by C<no warnings 'surrogate';>.
6143 =item Unknown charname '%s'
6145 (F) The name you used inside C<\N{}> is unknown to Perl. Check the
6146 spelling. You can say C<use charnames ":loose"> to not have to be
6147 so precise about spaces, hyphens, and capitalization on standard Unicode
6148 names. (Any custom aliases that have been created must be specified
6149 exactly, regardless of whether C<:loose> is used or not.) This error may
6150 also happen if the C<\N{}> is not in the scope of the corresponding
6151 C<S<use charnames>>.
6155 (P) Perl was about to print an error message in C<$@>, but the C<$@> variable
6156 did not exist, even after an attempt to create it.
6158 =item Unknown open() mode '%s'
6160 (F) The second argument of 3-argument open() is not among the list
6161 of valid modes: C<< < >>, C<< > >>, C<<< >> >>>, C<< +< >>,
6162 C<< +> >>, C<<< +>> >>>, C<-|>, C<|->, C<< <& >>, C<< >& >>.
6164 =item Unknown PerlIO layer "%s"
6166 (W layer) An attempt was made to push an unknown layer onto the Perl I/O
6167 system. (Layers take care of transforming data between external and
6168 internal representations.) Note that some layers, such as C<mmap>,
6169 are not supported in all environments. If your program didn't
6170 explicitly request the failing operation, it may be the result of the
6171 value of the environment variable PERLIO.
6173 =item Unknown process %x sent message to prime_env_iter: %s
6175 (P) An error peculiar to VMS. Perl was reading values for %ENV before
6176 iterating over it, and someone else stuck a message in the stream of
6177 data Perl expected. Someone's very confused, or perhaps trying to
6178 subvert Perl's population of %ENV for nefarious purposes.
6180 =item Unknown regex modifier "%s"
6182 (F) Alphanumerics immediately following the closing delimiter
6183 of a regular expression pattern are interpreted by Perl as modifier
6184 flags for the regex. One of the ones you specified is invalid. One way
6185 this can happen is if you didn't put in white space between the end of
6186 the regex and a following alphanumeric operator:
6188 if ($a =~ /foo/and $bar == 3) { ... }
6190 The C<"a"> is a valid modifier flag, but the C<"n"> is not, and raises
6191 this error. Likely what was meant instead was:
6193 if ($a =~ /foo/ and $bar == 3) { ... }
6195 =item Unknown "re" subpragma '%s' (known ones are: %s)
6197 (W) You tried to use an unknown subpragma of the "re" pragma.
6199 =item Unknown switch condition (?(...)) in regex; marked by S<<-- HERE> in
6202 (F) The condition part of a (?(condition)if-clause|else-clause) construct
6203 is not known. The condition must be one of the following:
6205 (1) (2) ... true if 1st, 2nd, etc., capture matched
6206 (<NAME>) ('NAME') true if named capture matched
6207 (?=...) (?<=...) true if subpattern matches
6208 (?!...) (?<!...) true if subpattern fails to match
6209 (?{ CODE }) true if code returns a true value
6210 (R) true if evaluating inside recursion
6211 (R1) (R2) ... true if directly inside capture group 1, 2, etc.
6212 (R&NAME) true if directly inside named capture
6213 (DEFINE) always false; for defining named subpatterns
6215 The <-- HERE shows whereabouts in the regular expression the problem was
6216 discovered. See L<perlre>.
6218 =item Unknown Unicode option letter '%c'
6220 (F) You specified an unknown Unicode option. See L<perlrun> documentation
6221 of the C<-C> switch for the list of known options.
6223 =item Unknown Unicode option value %d
6225 (F) You specified an unknown Unicode option. See L<perlrun> documentation
6226 of the C<-C> switch for the list of known options.
6228 =item Unknown verb pattern '%s' in regex; marked by S<<-- HERE> in m/%s/
6230 (F) You either made a typo or have incorrectly put a C<*> quantifier
6231 after an open brace in your pattern. Check the pattern and review
6232 L<perlre> for details on legal verb patterns.
6234 =item Unknown warnings category '%s'
6236 (F) An error issued by the C<warnings> pragma. You specified a warnings
6237 category that is unknown to perl at this point.
6239 Note that if you want to enable a warnings category registered by a
6240 module (e.g. C<use warnings 'File::Find'>), you must have loaded this
6243 =item Unmatched '[' in POSIX class in regex; marked by S<<-- HERE> in m/%s/
6245 (F) You had something like this:
6249 That should be written:
6253 =item Unmatched '%c' in POSIX class in regex; marked by S<<-- HERE> in
6256 (F) You had something like this:
6260 There should be a second C<":">, like this:
6264 =item Unmatched [ in regex; marked by S<<-- HERE> in m/%s/
6266 (F) The brackets around a character class must match. If you wish to
6267 include a closing bracket in a character class, backslash it or put it
6268 first. The S<<-- HERE> shows whereabouts in the regular expression the
6269 problem was discovered. See L<perlre>.
6271 =item Unmatched ( in regex; marked by S<<-- HERE> in m/%s/
6273 =item Unmatched ) in regex; marked by S<<-- HERE> in m/%s/
6275 (F) Unbackslashed parentheses must always be balanced in regular
6276 expressions. If you're a vi user, the % key is valuable for finding
6277 the matching parenthesis. The S<<-- HERE> shows whereabouts in the
6278 regular expression the problem was discovered. See L<perlre>.
6280 =item Unmatched right %s bracket
6282 (F) The lexer counted more closing curly or square brackets than opening
6283 ones, so you're probably missing a matching opening bracket. As a
6284 general rule, you'll find the missing one (so to speak) near the place
6285 you were last editing.
6287 =item Unquoted string "%s" may clash with future reserved word
6289 (W reserved) You used a bareword that might someday be claimed as a
6290 reserved word. It's best to put such a word in quotes, or capitalize it
6291 somehow, or insert an underbar into it. You might also declare it as a
6294 =item Unrecognized character %s; marked by S<<-- HERE> after %s near column
6297 (F) The Perl parser has no idea what to do with the specified character
6298 in your Perl script (or eval) near the specified column. Perhaps you
6299 tried to run a compressed script, a binary program, or a directory as
6302 =item Unrecognized escape \%c in character class in regex; marked by
6303 S<<-- HERE> in m/%s/
6305 (F) You used a backslash-character combination which is not
6306 recognized by Perl inside character classes. This is a fatal
6307 error when the character class is used within C<(?[ ])>.
6309 =item Unrecognized escape \%c in character class passed through in regex;
6310 marked by S<<-- HERE> in m/%s/
6312 (W regexp) You used a backslash-character combination which is not
6313 recognized by Perl inside character classes. The character was
6314 understood literally, but this may change in a future version of Perl.
6315 The S<<-- HERE> shows whereabouts in the regular expression the
6316 escape was discovered.
6318 =item Unrecognized escape \%c passed through
6320 (W misc) You used a backslash-character combination which is not
6321 recognized by Perl. The character was understood literally, but this may
6322 change in a future version of Perl.
6324 =item Unrecognized escape \%s passed through in regex; marked by
6325 S<<-- HERE> in m/%s/
6327 (W regexp) You used a backslash-character combination which is not
6328 recognized by Perl. The character(s) were understood literally, but
6329 this may change in a future version of Perl. The S<<-- HERE> shows
6330 whereabouts in the regular expression the escape was discovered.
6332 =item Unrecognized signal name "%s"
6334 (F) You specified a signal name to the kill() function that was not
6335 recognized. Say C<kill -l> in your shell to see the valid signal names
6338 =item Unrecognized switch: -%s (-h will show valid options)
6340 (F) You specified an illegal option to Perl. Don't do that. (If you
6341 think you didn't do that, check the #! line to see if it's supplying the
6342 bad switch on your behalf.)
6344 =item unshift on reference is experimental
6346 (S experimental::autoderef) C<unshift> with a scalar argument
6347 is experimental and may change or be removed in a future
6348 Perl version. If you want to take the risk of using this
6349 feature, simply disable this warning:
6351 no warnings "experimental::autoderef";
6353 =item Unsuccessful %s on filename containing newline
6355 (W newline) A file operation was attempted on a filename, and that
6356 operation failed, PROBABLY because the filename contained a newline,
6357 PROBABLY because you forgot to chomp() it off. See L<perlfunc/chomp>.
6359 =item Unsupported directory function "%s" called
6361 (F) Your machine doesn't support opendir() and readdir().
6363 =item Unsupported function %s
6365 (F) This machine doesn't implement the indicated function, apparently.
6366 At least, Configure doesn't think so.
6368 =item Unsupported function fork
6370 (F) Your version of executable does not support forking.
6372 Note that under some systems, like OS/2, there may be different flavors
6373 of Perl executables, some of which may support fork, some not. Try
6374 changing the name you call Perl by to C<perl_>, C<perl__>, and so on.
6376 =item Unsupported script encoding %s
6378 (F) Your program file begins with a Unicode Byte Order Mark (BOM) which
6379 declares it to be in a Unicode encoding that Perl cannot read.
6381 =item Unsupported socket function "%s" called
6383 (F) Your machine doesn't support the Berkeley socket mechanism, or at
6384 least that's what Configure thought.
6386 =item Unterminated attribute list
6388 (F) The lexer found something other than a simple identifier at the
6389 start of an attribute, and it wasn't a semicolon or the start of a
6390 block. Perhaps you terminated the parameter list of the previous
6391 attribute too soon. See L<attributes>.
6393 =item Unterminated attribute parameter in attribute list
6395 (F) The lexer saw an opening (left) parenthesis character while parsing
6396 an attribute list, but the matching closing (right) parenthesis
6397 character was not found. You may need to add (or remove) a backslash
6398 character to get your parentheses to balance. See L<attributes>.
6400 =item Unterminated compressed integer
6402 (F) An argument to unpack("w",...) was incompatible with the BER
6403 compressed integer format and could not be converted to an integer.
6404 See L<perlfunc/pack>.
6406 =item Unterminated delimiter for here document
6408 (F) This message occurs when a here document label has an initial
6409 quotation mark but the final quotation mark is missing. Perhaps
6418 =item Unterminated \g... pattern in regex; marked by S<<-- HERE> in m/%s/
6420 =item Unterminated \g{...} pattern in regex; marked by S<<-- HERE> in m/%s/
6422 (F) In a regular expression, you had a C<\g> that wasn't followed by a
6423 proper group reference. In the case of C<\g{>, the closing brace is
6424 missing; otherwise the C<\g> must be followed by an integer. Fix the
6427 =item Unterminated <> operator
6429 (F) The lexer saw a left angle bracket in a place where it was expecting
6430 a term, so it's looking for the corresponding right angle bracket, and
6431 not finding it. Chances are you left some needed parentheses out
6432 earlier in the line, and you really meant a "less than".
6434 =item Unterminated verb pattern argument in regex; marked by S<<-- HERE> in
6437 (F) You used a pattern of the form C<(*VERB:ARG)> but did not terminate
6438 the pattern with a C<)>. Fix the pattern and retry.
6440 =item Unterminated verb pattern in regex; marked by S<<-- HERE> in m/%s/
6442 (F) You used a pattern of the form C<(*VERB)> but did not terminate
6443 the pattern with a C<)>. Fix the pattern and retry.
6445 =item untie attempted while %d inner references still exist
6447 (W untie) A copy of the object returned from C<tie> (or C<tied>) was
6448 still valid when C<untie> was called.
6450 =item Usage: POSIX::%s(%s)
6452 (F) You called a POSIX function with incorrect arguments.
6453 See L<POSIX/FUNCTIONS> for more information.
6455 =item Usage: Win32::%s(%s)
6457 (F) You called a Win32 function with incorrect arguments.
6458 See L<Win32> for more information.
6460 =item $[ used in %s (did you mean $] ?)
6462 (W syntax) You used C<$[> in a comparison, such as:
6468 You probably meant to use C<$]> instead. C<$[> is the base for indexing
6469 arrays. C<$]> is the Perl version number in decimal.
6471 =item Use "%s" instead of "%s"
6473 (F) The second listed construct is no longer legal. Use the first one
6476 =item Useless assignment to a temporary
6478 (W misc) You assigned to an lvalue subroutine, but what
6479 the subroutine returned was a temporary scalar about to
6480 be discarded, so the assignment had no effect.
6482 =item Useless (?-%s) - don't use /%s modifier in regex; marked by
6483 S<<-- HERE> in m/%s/
6485 (W regexp) You have used an internal modifier such as (?-o) that has no
6486 meaning unless removed from the entire regexp:
6488 if ($string =~ /(?-o)$pattern/o) { ... }
6492 if ($string =~ /$pattern/) { ... }
6494 The <-- HERE shows whereabouts in the regular expression the problem was
6495 discovered. See L<perlre>.
6497 =item Useless localization of %s
6499 (W syntax) The localization of lvalues such as C<local($x=10)> is legal,
6500 but in fact the local() currently has no effect. This may change at
6501 some point in the future, but in the meantime such code is discouraged.
6503 =item Useless (?%s) - use /%s modifier in regex; marked by S<<-- HERE> in
6506 (W regexp) You have used an internal modifier such as (?o) that has no
6507 meaning unless applied to the entire regexp:
6509 if ($string =~ /(?o)$pattern/) { ... }
6513 if ($string =~ /$pattern/o) { ... }
6515 The <-- HERE shows whereabouts in the regular expression the problem was
6516 discovered. See L<perlre>.
6518 =item Useless use of attribute "const"
6520 (W misc) The "const" attribute has no effect except
6521 on anonymous closure prototypes. You applied it to
6522 a subroutine via L<attributes.pm|attributes>. This is only useful
6523 inside an attribute handler for an anonymous subroutine.
6525 =item Useless use of /d modifier in transliteration operator
6527 (W misc) You have used the /d modifier where the searchlist has the
6528 same length as the replacelist. See L<perlop> for more information
6529 about the /d modifier.
6531 =item Useless use of \E
6533 (W misc) You have a \E in a double-quotish string without a C<\U>,
6534 C<\L> or C<\Q> preceding it.
6536 =item Useless use of greediness modifier '%c' in regex; marked by S<<-- HERE> in m/%s/
6538 (W regexp) You specified something like these:
6543 The C<"?"> and C<"+"> don't have any effect, as they modify whether to
6544 match more or fewer when there is a choice, and by specifying to match
6545 exactly a given numer, there is no room left for a choice.
6547 =item Useless use of %s in void context
6549 (W void) You did something without a side effect in a context that does
6550 nothing with the return value, such as a statement that doesn't return a
6551 value from a block, or the left side of a scalar comma operator. Very
6552 often this points not to stupidity on your part, but a failure of Perl
6553 to parse your program the way you thought it would. For example, you'd
6554 get this if you mixed up your C precedence with Python precedence and
6559 when you meant to say
6561 ($one, $two) = (1, 2);
6563 Another common error is to use ordinary parentheses to construct a list
6564 reference when you should be using square or curly brackets, for
6569 when you should have said
6573 The square brackets explicitly turn a list value into a scalar value,
6574 while parentheses do not. So when a parenthesized list is evaluated in
6575 a scalar context, the comma is treated like C's comma operator, which
6576 throws away the left argument, which is not what you want. See
6577 L<perlref> for more on this.
6579 This warning will not be issued for numerical constants equal to 0 or 1
6580 since they are often used in statements like
6582 1 while sub_with_side_effects();
6584 String constants that would normally evaluate to 0 or 1 are warned
6587 =item Useless use of (?-p) in regex; marked by S<<-- HERE> in m/%s/
6589 (W regexp) The C<p> modifier cannot be turned off once set. Trying to do
6592 =item Useless use of "re" pragma
6594 (W) You did C<use re;> without any arguments. That isn't very useful.
6596 =item Useless use of sort in scalar context
6598 (W void) You used sort in scalar context, as in :
6602 This is not very useful, and perl currently optimizes this away.
6604 =item Useless use of %s with no values
6606 (W syntax) You used the push() or unshift() function with no arguments
6607 apart from the array, like C<push(@x)> or C<unshift(@foo)>. That won't
6608 usually have any effect on the array, so is completely useless. It's
6609 possible in principle that push(@tied_array) could have some effect
6610 if the array is tied to a class which implements a PUSH method. If so,
6611 you can write it as C<push(@tied_array,())> to avoid this warning.
6613 =item "use" not allowed in expression
6615 (F) The "use" keyword is recognized and executed at compile time, and
6616 returns no useful value. See L<perlmod>.
6618 =item Use of assignment to $[ is deprecated
6620 (D deprecated) The C<$[> variable (index of the first element in an array)
6621 is deprecated. See L<perlvar/"$[">.
6623 =item Use of bare << to mean <<"" is deprecated
6625 (D deprecated) You are now encouraged to use the explicitly quoted
6626 form if you wish to use an empty line as the terminator of the
6629 =item Use of chdir('') or chdir(undef) as chdir() deprecated
6631 (D deprecated) chdir() with no arguments is documented to change to
6632 $ENV{HOME} or $ENV{LOGDIR}. chdir(undef) and chdir('') share this
6633 behavior, but that has been deprecated. In future versions they
6636 Be careful to check that what you pass to chdir() is defined and not
6637 blank, else you might find yourself in your home directory.
6639 =item Use of /c modifier is meaningless in s///
6641 (W regexp) You used the /c modifier in a substitution. The /c
6642 modifier is not presently meaningful in substitutions.
6644 =item Use of /c modifier is meaningless without /g
6646 (W regexp) You used the /c modifier with a regex operand, but didn't
6647 use the /g modifier. Currently, /c is meaningful only when /g is
6648 used. (This may change in the future.)
6650 =item Use of comma-less variable list is deprecated
6652 (D deprecated) The values you give to a format should be
6653 separated by commas, not just aligned on a line.
6655 =item Use of each() on hash after insertion without resetting hash iterator results in undefined behavior
6657 (S internal) The behavior of C<each()> after insertion is undefined;
6658 it may skip items, or visit items more than once. Consider using
6659 C<keys()> instead of C<each()>.
6661 =item Use of := for an empty attribute list is not allowed
6663 (F) The construction C<my $x := 42> used to parse as equivalent to
6664 C<my $x : = 42> (applying an empty attribute list to C<$x>).
6665 This construct was deprecated in 5.12.0, and has now been made a syntax
6666 error, so C<:=> can be reclaimed as a new operator in the future.
6668 If you need an empty attribute list, for example in a code generator, add
6669 a space before the C<=>.
6671 =item Use of freed value in iteration
6673 (F) Perhaps you modified the iterated array within the loop?
6674 This error is typically caused by code like the following:
6677 @a = () for (1,2,@a);
6679 You are not supposed to modify arrays while they are being iterated over.
6680 For speed and efficiency reasons, Perl internally does not do full
6681 reference-counting of iterated items, hence deleting such an item in the
6682 middle of an iteration causes Perl to see a freed value.
6684 =item Use of *glob{FILEHANDLE} is deprecated
6686 (D deprecated) You are now encouraged to use the shorter *glob{IO} form
6687 to access the filehandle slot within a typeglob.
6689 =item Use of /g modifier is meaningless in split
6691 (W regexp) You used the /g modifier on the pattern for a C<split>
6692 operator. Since C<split> always tries to match the pattern
6693 repeatedly, the C</g> has no effect.
6695 =item Use of "goto" to jump into a construct is deprecated
6697 (D deprecated) Using C<goto> to jump from an outer scope into an inner
6698 scope is deprecated and should be avoided.
6700 =item Use of inherited AUTOLOAD for non-method %s() is deprecated
6702 (D deprecated) As an (ahem) accidental feature, C<AUTOLOAD>
6703 subroutines are looked up as methods (using the C<@ISA> hierarchy)
6704 even when the subroutines to be autoloaded were called as plain
6705 functions (e.g. C<Foo::bar()>), not as methods (e.g. C<< Foo->bar() >> or
6706 C<< $obj->bar() >>).
6708 This bug will be rectified in future by using method lookup only for
6709 methods' C<AUTOLOAD>s. However, there is a significant base of existing
6710 code that may be using the old behavior. So, as an interim step, Perl
6711 currently issues an optional warning when non-methods use inherited
6714 The simple rule is: Inheritance will not work when autoloading
6715 non-methods. The simple fix for old code is: In any module that used
6716 to depend on inheriting C<AUTOLOAD> for non-methods from a base class
6717 named C<BaseClass>, execute C<*AUTOLOAD = \&BaseClass::AUTOLOAD> during
6720 In code that currently says C<use AutoLoader; @ISA = qw(AutoLoader);>
6721 you should remove AutoLoader from @ISA and change C<use AutoLoader;> to
6722 C<use AutoLoader 'AUTOLOAD';>.
6724 =item Use of %s in printf format not supported
6726 (F) You attempted to use a feature of printf that is accessible from
6727 only C. This usually means there's a better way to do it in Perl.
6729 =item Use of %s is deprecated
6731 (D deprecated) The construct indicated is no longer recommended for use,
6732 generally because there's a better way to do it, and also because the
6733 old way has bad side effects.
6735 =item Use of literal control characters in variable names is deprecated
6737 =item Use of literal non-graphic characters in variable names is deprecated
6739 (D deprecated) Using literal non-graphic (including control)
6740 characters in the source to refer to the ^FOO variables, like C<$^X> and
6741 C<${^GLOBAL_PHASE}> is now deprecated. (We use C<^X> and C<^G> here for
6742 legibility. They actually represent the non-printable control
6743 characters, code points 0x18 and 0x07, respectively; C<^A> would mean
6744 the control character whose code point is 0x01.) This only affects
6745 code like C<$\cT>, where C<\cT> is a control in the source code; C<${"\cT"}> and
6746 C<$^T> remain valid. Things that are non-controls and also not graphic
6747 are NO-BREAK SPACE and SOFT HYPHEN, which were previously only allowed
6748 for historical reasons.
6750 =item Use of -l on filehandle%s
6752 (W io) A filehandle represents an opened file, and when you opened the file
6753 it already went past any symlink you are presumably trying to look for.
6754 The operation returned C<undef>. Use a filename instead.
6756 =item Use of my $_ is experimental
6758 (S experimental::lexical_topic) Lexical $_ is an experimental feature and
6759 its behavior may change or even be removed in any future release of perl.
6760 See the explanation under L<perlvar/$_>.
6762 =item Use of %s on a handle without * is deprecated
6764 (D deprecated) You used C<tie>, C<tied> or C<untie> on a scalar but that scalar
6765 happens to hold a typeglob, which means its filehandle will be tied. If
6766 you mean to tie a handle, use an explicit * as in C<tie *$handle>.
6768 This was a long-standing bug that was removed in Perl 5.16, as there was
6769 no way to tie the scalar itself when it held a typeglob, and no way to
6770 untie a scalar that had had a typeglob assigned to it. If you see this
6771 message, you must be using an older version.
6773 =item Use of reference "%s" as array index
6775 (W misc) You tried to use a reference as an array index; this probably
6776 isn't what you mean, because references in numerical context tend
6777 to be huge numbers, and so usually indicates programmer error.
6779 If you really do mean it, explicitly numify your reference, like so:
6780 C<$array[0+$ref]>. This warning is not given for overloaded objects,
6781 however, because you can overload the numification and stringification
6782 operators and then you presumably know what you are doing.
6784 =item Use of state $_ is experimental
6786 (S experimental::lexical_topic) Lexical $_ is an experimental feature and
6787 its behavior may change or even be removed in any future release of perl.
6788 See the explanation under L<perlvar/$_>.
6790 =item Use of tainted arguments in %s is deprecated
6792 (W taint, deprecated) You have supplied C<system()> or C<exec()> with multiple
6793 arguments and at least one of them is tainted. This used to be allowed
6794 but will become a fatal error in a future version of perl. Untaint your
6795 arguments. See L<perlsec>.
6797 =item Use of uninitialized value%s
6799 (W uninitialized) An undefined value was used as if it were already
6800 defined. It was interpreted as a "" or a 0, but maybe it was a mistake.
6801 To suppress this warning assign a defined value to your variables.
6803 To help you figure out what was undefined, perl will try to tell you
6804 the name of the variable (if any) that was undefined. In some cases
6805 it cannot do this, so it also tells you what operation you used the
6806 undefined value in. Note, however, that perl optimizes your program
6807 and the operation displayed in the warning may not necessarily appear
6808 literally in your program. For example, C<"that $foo"> is usually
6809 optimized into C<"that " . $foo>, and the warning will refer to the
6810 C<concatenation (.)> operator, even though there is no C<.> in
6813 =item "use re 'strict'" is experimental
6815 (S experimental::re_strict) The things that are different when a regular
6816 expression pattern is compiled under C<'strict'> are subject to change
6817 in future Perl releases in incompatible ways. This means that a pattern
6818 that compiles today may not in a future Perl release. This warning is
6819 to alert you to that risk.
6821 =item Use \x{...} for more than two hex characters in regex; marked by
6822 S<<-- HERE> in m/%s/
6824 (F) In a regular expression, you said something like
6828 Perl isn't sure if you meant this
6832 or if you meant this
6834 (?[ [ \x{BE} E F ] ])
6836 You need to add either braces or blanks to disambiguate.
6838 =item Using just the first character returned by \N{} in character class in
6839 regex; marked by S<<-- HERE> in m/%s/
6841 (W regexp) Named Unicode character escapes C<(\N{...})> may return
6842 a multi-character sequence. Even though a character class is
6843 supposed to match just one character of input, perl will match
6844 the whole thing correctly, except when the class is inverted
6845 (C<[^...]>), or the escape is the beginning or final end point of
6846 a range. For these, what should happen isn't clear at all. In
6847 these circumstances, Perl discards all but the first character
6848 of the returned sequence, which is not likely what you want.
6850 =item Using !~ with %s doesn't make sense
6852 (F) Using the C<!~> operator with C<s///r>, C<tr///r> or C<y///r> is
6853 currently reserved for future use, as the exact behavior has not
6854 been decided. (Simply returning the boolean opposite of the
6855 modified string is usually not particularly useful.)
6857 =item UTF-16 surrogate U+%X
6859 (S surrogate) You had a UTF-16 surrogate in a context where they are
6860 not considered acceptable. These code points, between U+D800 and
6861 U+DFFF (inclusive), are used by Unicode only for UTF-16. However, Perl
6862 internally allows all unsigned integer code points (up to the size limit
6863 available on your platform), including surrogates. But these can cause
6864 problems when being input or output, which is likely where this message
6865 came from. If you really really know what you are doing you can turn
6866 off this warning by C<no warnings 'surrogate';>.
6868 =item Value of %s can be "0"; test with defined()
6870 (W misc) In a conditional expression, you used <HANDLE>, <*> (glob),
6871 C<each()>, or C<readdir()> as a boolean value. Each of these constructs
6872 can return a value of "0"; that would make the conditional expression
6873 false, which is probably not what you intended. When using these
6874 constructs in conditional expressions, test their values with the
6875 C<defined> operator.
6877 =item Value of CLI symbol "%s" too long
6879 (W misc) A warning peculiar to VMS. Perl tried to read the value of an
6880 %ENV element from a CLI symbol table, and found a resultant string
6881 longer than 1024 characters. The return value has been truncated to
6884 =item values on reference is experimental
6886 (S experimental::autoderef) C<values> with a scalar argument
6887 is experimental and may change or be removed in a future
6888 Perl version. If you want to take the risk of using this
6889 feature, simply disable this warning:
6891 no warnings "experimental::autoderef";
6893 =item Variable "%s" is not available
6895 (W closure) During compilation, an inner named subroutine or eval is
6896 attempting to capture an outer lexical that is not currently available.
6897 This can happen for one of two reasons. First, the outer lexical may be
6898 declared in an outer anonymous subroutine that has not yet been created.
6899 (Remember that named subs are created at compile time, while anonymous
6900 subs are created at run-time.) For example,
6902 sub { my $a; sub f { $a } }
6904 At the time that f is created, it can't capture the current value of $a,
6905 since the anonymous subroutine hasn't been created yet. Conversely,
6906 the following won't give a warning since the anonymous subroutine has by
6907 now been created and is live:
6909 sub { my $a; eval 'sub f { $a }' }->();
6911 The second situation is caused by an eval accessing a variable that has
6912 gone out of scope, for example,
6920 Here, when the '$a' in the eval is being compiled, f() is not currently
6921 being executed, so its $a is not available for capture.
6923 =item Variable "%s" is not imported%s
6925 (S misc) With "use strict" in effect, you referred to a global variable
6926 that you apparently thought was imported from another module, because
6927 something else of the same name (usually a subroutine) is exported by
6928 that module. It usually means you put the wrong funny character on the
6929 front of your variable.
6931 =item Variable length lookbehind not implemented in regex m/%s/
6933 (F) Lookbehind is allowed only for subexpressions whose length is fixed and
6934 known at compile time. For positive lookbehind, you can use the C<\K>
6935 regex construct as a way to get the equivalent functionality. See
6936 L<perlre/(?<=pattern) \K>.
6938 There are non-obvious Unicode rules under C</i> that can match variably,
6939 but which you might not think could. For example, the substring C<"ss">
6940 can match the single character LATIN SMALL LETTER SHARP S. There are
6941 other sequences of ASCII characters that can match single ligature
6942 characters, such as LATIN SMALL LIGATURE FFI matching C<qr/ffi/i>.
6943 Starting in Perl v5.16, if you only care about ASCII matches, adding the
6944 C</aa> modifier to the regex will exclude all these non-obvious matches,
6945 thus getting rid of this message. You can also say C<S<use re qw(/aa)>>
6946 to apply C</aa> to all regular expressions compiled within its scope.
6949 =item "%s" variable %s masks earlier declaration in same %s
6951 (W misc) A "my", "our" or "state" variable has been redeclared in the
6952 current scope or statement, effectively eliminating all access to the
6953 previous instance. This is almost always a typographical error. Note
6954 that the earlier variable will still exist until the end of the scope
6955 or until all closure references to it are destroyed.
6957 =item Variable syntax
6959 (A) You've accidentally run your script through B<csh> instead
6960 of Perl. Check the #! line, or manually feed your script into
6963 =item Variable "%s" will not stay shared
6965 (W closure) An inner (nested) I<named> subroutine is referencing a
6966 lexical variable defined in an outer named subroutine.
6968 When the inner subroutine is called, it will see the value of
6969 the outer subroutine's variable as it was before and during the *first*
6970 call to the outer subroutine; in this case, after the first call to the
6971 outer subroutine is complete, the inner and outer subroutines will no
6972 longer share a common value for the variable. In other words, the
6973 variable will no longer be shared.
6975 This problem can usually be solved by making the inner subroutine
6976 anonymous, using the C<sub {}> syntax. When inner anonymous subs that
6977 reference variables in outer subroutines are created, they
6978 are automatically rebound to the current values of such variables.
6980 =item vector argument not supported with alpha versions
6982 (S printf) The %vd (s)printf format does not support version objects
6985 =item Verb pattern '%s' has a mandatory argument in regex; marked by
6986 S<<-- HERE> in m/%s/
6988 (F) You used a verb pattern that requires an argument. Supply an
6989 argument or check that you are using the right verb.
6991 =item Verb pattern '%s' may not have an argument in regex; marked by
6992 S<<-- HERE> in m/%s/
6994 (F) You used a verb pattern that is not allowed an argument. Remove the
6995 argument or check that you are using the right verb.
6997 =item Version number must be a constant number
6999 (P) The attempt to translate a C<use Module n.n LIST> statement into
7000 its equivalent C<BEGIN> block found an internal inconsistency with
7003 =item Version string '%s' contains invalid data; ignoring: '%s'
7005 (W misc) The version string contains invalid characters at the end, which
7008 =item Warning: something's wrong
7010 (W) You passed warn() an empty string (the equivalent of C<warn "">) or
7011 you called it with no args and C<$@> was empty.
7013 =item Warning: unable to close filehandle %s properly
7015 (S) The implicit close() done by an open() got an error indication on
7016 the close(). This usually indicates your file system ran out of disk
7019 =item Warning: unable to close filehandle properly: %s
7021 =item Warning: unable to close filehandle %s properly: %s
7023 (S io) An error occurred when Perl implicitly closed a filehandle. This
7024 usually indicates your file system ran out of disk space.
7026 =item Warning: Use of "%s" without parentheses is ambiguous
7028 (S ambiguous) You wrote a unary operator followed by something that
7029 looks like a binary operator that could also have been interpreted as a
7030 term or unary operator. For instance, if you know that the rand
7031 function has a default argument of 1.0, and you write
7035 you may THINK you wrote the same thing as
7039 but in actual fact, you got
7043 So put in parentheses to say what you really mean.
7045 =item when is experimental
7047 (S experimental::smartmatch) C<when> depends on smartmatch, which is
7048 experimental. Additionally, it has several special cases that may
7049 not be immediately obvious, and their behavior may change or
7050 even be removed in any future release of perl. See the explanation
7051 under L<perlsyn/Experimental Details on given and when>.
7053 =item Wide character in %s
7055 (S utf8) Perl met a wide character (>255) when it wasn't expecting
7056 one. This warning is by default on for I/O (like print). The easiest
7057 way to quiet this warning is simply to add the C<:utf8> layer to the
7058 output, e.g. C<binmode STDOUT, ':utf8'>. Another way to turn off the
7059 warning is to add C<no warnings 'utf8';> but that is often closer to
7060 cheating. In general, you are supposed to explicitly mark the
7061 filehandle with an encoding, see L<open> and L<perlfunc/binmode>.
7063 =item Wide character (U+%X) in %s
7065 (W locale) While in a single-byte locale (I<i.e.>, a non-UTF-8
7066 one), a multi-byte character was encountered. Perl considers this
7067 character to be the specified Unicode code point. Combining non-UTF8
7068 locales and Unicode is dangerous. Almost certainly some characters
7069 will have two different representations. For example, in the ISO 8859-7
7070 (Greek) locale, the code point 0xC3 represents a Capital Gamma. But so
7071 also does 0x393. This will make string comparisons unreliable.
7073 You likely need to figure out how this multi-byte character got mixed up
7074 with your single-byte locale (or perhaps you thought you had a UTF-8
7075 locale, but Perl disagrees).
7077 =item Within []-length '%c' not allowed
7079 (F) The count in the (un)pack template may be replaced by C<[TEMPLATE]>
7080 only if C<TEMPLATE> always matches the same amount of packed bytes that
7081 can be determined from the template alone. This is not possible if
7082 it contains any of the codes @, /, U, u, w or a *-length. Redesign
7085 =item write() on closed filehandle %s
7087 (W closed) The filehandle you're writing to got itself closed sometime
7088 before now. Check your control flow.
7090 =item %s "\x%X" does not map to Unicode
7092 (S utf8) When reading in different encodings, Perl tries to
7093 map everything into Unicode characters. The bytes you read
7094 in are not legal in this encoding. For example
7096 utf8 "\xE4" does not map to Unicode
7098 if you try to read in the a-diaereses Latin-1 as UTF-8.
7100 =item 'X' outside of string
7102 (F) You had a (un)pack template that specified a relative position before
7103 the beginning of the string being (un)packed. See L<perlfunc/pack>.
7105 =item 'x' outside of string in unpack
7107 (F) You had a pack template that specified a relative position after
7108 the end of the string being unpacked. See L<perlfunc/pack>.
7110 =item YOU HAVEN'T DISABLED SET-ID SCRIPTS IN THE KERNEL YET!
7112 (F) And you probably never will, because you probably don't have the
7113 sources to your kernel, and your vendor probably doesn't give a rip
7114 about what you want. Your best bet is to put a setuid C wrapper around
7117 =item You need to quote "%s"
7119 (W syntax) You assigned a bareword as a signal handler name.
7120 Unfortunately, you already have a subroutine of that name declared,
7121 which means that Perl 5 will try to call the subroutine when the
7122 assignment is executed, which is probably not what you want. (If it IS
7123 what you want, put an & in front.)
7125 =item Your random numbers are not that random
7127 (F) When trying to initialize the random seed for hashes, Perl could
7128 not get any randomness out of your system. This usually indicates
7129 Something Very Wrong.
7131 =item Zero length \N{} in regex; marked by S<<-- HERE> in m/%s/
7133 (F) Named Unicode character escapes (C<\N{...}>) may return a zero-length
7134 sequence. Such an escape was used in an extended character class, i.e.
7135 C<(?[...])>, which is not permitted. Check that the correct escape has
7136 been used, and the correct charnames handler is in scope. The S<<-- HERE>
7137 shows whereabouts in the regular expression the problem was discovered.
7143 L<warnings>, L<diagnostics>.