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 alpha->numify() is lossy
77 (W numeric) An alpha version can not be numified without losing
80 =item Ambiguous call resolved as CORE::%s(), qualify as such or use &
82 (W ambiguous) A subroutine you have declared has the same name as a Perl
83 keyword, and you have used the name without qualification for calling
84 one or the other. Perl decided to call the builtin because the
85 subroutine is not imported.
87 To force interpretation as a subroutine call, either put an ampersand
88 before the subroutine name, or qualify the name with its package.
89 Alternatively, you can import the subroutine (or pretend that it's
90 imported with the C<use subs> pragma).
92 To silently interpret it as the Perl operator, use the C<CORE::> prefix
93 on the operator (e.g. C<CORE::log($x)>) or declare the subroutine
94 to be an object method (see L<perlsub/"Subroutine Attributes"> or
97 =item Ambiguous range in transliteration operator
99 (F) You wrote something like C<tr/a-z-0//> which doesn't mean anything at
100 all. To include a C<-> character in a transliteration, put it either
101 first or last. (In the past, C<tr/a-z-0//> was synonymous with
102 C<tr/a-y//>, which was probably not what you would have expected.)
104 =item Ambiguous use of %s resolved as %s
106 (S ambiguous) You said something that may not be interpreted the way
107 you thought. Normally it's pretty easy to disambiguate it by supplying
108 a missing quote, operator, parenthesis pair or declaration.
110 =item Ambiguous use of -%s resolved as -&%s()
112 (S ambiguous) You wrote something like C<-foo>, which might be the
113 string C<"-foo">, or a call to the function C<foo>, negated. If you meant
114 the string, just write C<"-foo">. If you meant the function call,
117 =item Ambiguous use of %c resolved as operator %c
119 (S ambiguous) C<%>, C<&>, and C<*> are both infix operators (modulus,
120 bitwise and, and multiplication) I<and> initial special characters
121 (denoting hashes, subroutines and typeglobs), and you said something
122 like C<*foo * foo> that might be interpreted as either of them. We
123 assumed you meant the infix operator, but please try to make it more
124 clear -- in the example given, you might write C<*foo * foo()> if you
125 really meant to multiply a glob by the result of calling a function.
127 =item Ambiguous use of %c{%s} resolved to %c%s
129 (W ambiguous) You wrote something like C<@{foo}>, which might be
130 asking for the variable C<@foo>, or it might be calling a function
131 named foo, and dereferencing it as an array reference. If you wanted
132 the variable, you can just write C<@foo>. If you wanted to call the
133 function, write C<@{foo()}> ... or you could just not have a variable
134 and a function with the same name, and save yourself a lot of trouble.
136 =item Ambiguous use of %c{%s[...]} resolved to %c%s[...]
138 =item Ambiguous use of %c{%s{...}} resolved to %c%s{...}
140 (W ambiguous) You wrote something like C<${foo[2]}> (where foo represents
141 the name of a Perl keyword), which might be looking for element number
142 2 of the array named C<@foo>, in which case please write C<$foo[2]>, or you
143 might have meant to pass an anonymous arrayref to the function named
144 foo, and then do a scalar deref on the value it returns. If you meant
145 that, write C<${foo([2])}>.
147 In regular expressions, the C<${foo[2]}> syntax is sometimes necessary
148 to disambiguate between array subscripts and character classes.
149 C</$length[2345]/>, for instance, will be interpreted as C<$length> followed
150 by the character class C<[2345]>. If an array subscript is what you
151 want, you can avoid the warning by changing C</${length[2345]}/> to the
152 unsightly C</${\$length[2345]}/>, by renaming your array to something
153 that does not coincide with a built-in keyword, or by simply turning
154 off warnings with C<no warnings 'ambiguous';>.
156 =item '|' and '<' may not both be specified on command line
158 (F) An error peculiar to VMS. Perl does its own command line
159 redirection, and found that STDIN was a pipe, and that you also tried to
160 redirect STDIN using '<'. Only one STDIN stream to a customer, please.
162 =item '|' and '>' may not both be specified on command line
164 (F) An error peculiar to VMS. Perl does its own command line
165 redirection, and thinks you tried to redirect stdout both to a file and
166 into a pipe to another command. You need to choose one or the other,
167 though nothing's stopping you from piping into a program or Perl script
168 which 'splits' output into two streams, such as
170 open(OUT,">$ARGV[0]") or die "Can't write to $ARGV[0]: $!";
177 =item Applying %s to %s will act on scalar(%s)
179 (W misc) The pattern match (C<//>), substitution (C<s///>), and
180 transliteration (C<tr///>) operators work on scalar values. If you apply
181 one of them to an array or a hash, it will convert the array or hash to
182 a scalar value (the length of an array, or the population info of a
183 hash) and then work on that scalar value. This is probably not what
184 you meant to do. See L<perlfunc/grep> and L<perlfunc/map> for
187 =item Arg too short for msgsnd
189 (F) msgsnd() requires a string at least as long as sizeof(long).
191 =item Argument "%s" isn't numeric%s
193 (W numeric) The indicated string was fed as an argument to an operator
194 that expected a numeric value instead. If you're fortunate the message
195 will identify which operator was so unfortunate.
197 Note that for the C<Inf> and C<NaN> (infinity and not-a-number) the
198 definition of "numeric" is somewhat unusual: the strings themselves
199 (like "Inf") are considered numeric, and anything following them is
200 considered non-numeric.
202 =item Argument list not closed for PerlIO layer "%s"
204 (W layer) When pushing a layer with arguments onto the Perl I/O
205 system you forgot the ) that closes the argument list. (Layers
206 take care of transforming data between external and internal
207 representations.) Perl stopped parsing the layer list at this
208 point and did not attempt to push this layer. If your program
209 didn't explicitly request the failing operation, it may be the
210 result of the value of the environment variable PERLIO.
212 =item Argument "%s" treated as 0 in increment (++)
214 (W numeric) The indicated string was fed as an argument to the C<++>
215 operator which expects either a number or a string matching
216 C</^[a-zA-Z]*[0-9]*\z/>. See L<perlop/Auto-increment and
217 Auto-decrement> for details.
219 =item Array passed to stat will be coerced to a scalar%s
221 (W syntax) You called stat() on an array, but the array will be
222 coerced to a scalar - the number of elements in the array.
224 =item A signature parameter must start with '$', '@' or '%'
226 (F) Each subroutine signature parameter declaration must start with a valid
229 sub foo ($a, $, $b = 1, @c) {}
231 =item A slurpy parameter may not have a default value
233 (F) Only scalar subroutine signature parameters may have a default value;
236 sub foo ($a = 1) {} # legal
237 sub foo (@a = (1)) {} # invalid
238 sub foo (%a = (a => b)) {} # invalid
240 =item assertion botched: %s
242 (X) The malloc package that comes with Perl had an internal failure.
244 =item Assertion %s failed: file "%s", line %d
246 (X) A general assertion failed. The file in question must be examined.
248 =item Assigned value is not a reference
250 (F) You tried to assign something that was not a reference to an lvalue
251 reference (e.g., C<\$x = $y>). If you meant to make $x an alias to $y, use
254 =item Assigned value is not %s reference
256 (F) You tried to assign a reference to a reference constructor, but the
257 two references were not of the same type. You cannot alias a scalar to
258 an array, or an array to a hash; the two types must match.
263 \$x = $y; # error; did you mean \$y?
265 =item Assigning non-zero to $[ is no longer possible
267 (F) When the "array_base" feature is disabled
268 (e.g., and under C<use v5.16;>, and as of Perl 5.30)
269 the special variable C<$[>, which is deprecated, is now a fixed zero value.
271 =item Assignment to both a list and a scalar
273 (F) If you assign to a conditional operator, the 2nd and 3rd arguments
274 must either both be scalars or both be lists. Otherwise Perl won't
275 know which context to supply to the right side.
277 =item Assuming NOT a POSIX class since %s in regex; marked by S<<-- HERE> in m/%s/
279 (W regexp) You had something like these:
284 They look like they might have been meant to be the POSIX classes
285 C<[:alnum:]> or C<[:digit:]>. If so, they should be written:
290 Since these aren't legal POSIX class specifications, but are legal
291 bracketed character classes, Perl treats them as the latter. In the
292 first example, it matches the characters C<":">, C<"[">, C<"a">, C<"l">,
293 C<"m">, C<"n">, and C<"u">.
295 If these weren't meant to be POSIX classes, this warning message is
296 spurious, and can be suppressed by reordering things, such as
304 =item <> at require-statement should be quotes
306 (F) You wrote C<< require <file> >> when you should have written
309 =item Attempt to access disallowed key '%s' in a restricted hash
311 (F) The failing code has attempted to get or set a key which is not in
312 the current set of allowed keys of a restricted hash.
314 =item Attempt to bless into a freed package
316 (F) You wrote C<bless $foo> with one argument after somehow causing
317 the current package to be freed. Perl cannot figure out what to
318 do, so it throws up its hands in despair.
320 =item Attempt to bless into a reference
322 (F) The CLASSNAME argument to the bless() operator is expected to be
323 the name of the package to bless the resulting object into. You've
324 supplied instead a reference to something: perhaps you wrote
330 bless $self, ref($proto) || $proto;
332 If you actually want to bless into the stringified version
333 of the reference supplied, you need to stringify it yourself, for
336 bless $self, "$proto";
338 =item Attempt to clear deleted array
340 (S debugging) An array was assigned to when it was being freed.
341 Freed values are not supposed to be visible to Perl code. This
342 can also happen if XS code calls C<av_clear> from a custom magic
343 callback on the array.
345 =item Attempt to delete disallowed key '%s' from a restricted hash
347 (F) The failing code attempted to delete from a restricted hash a key
348 which is not in its key set.
350 =item Attempt to delete readonly key '%s' from a restricted hash
352 (F) The failing code attempted to delete a key whose value has been
353 declared readonly from a restricted hash.
355 =item Attempt to free non-arena SV: 0x%x
357 (S internal) All SV objects are supposed to be allocated from arenas
358 that will be garbage collected on exit. An SV was discovered to be
359 outside any of those arenas.
361 =item Attempt to free nonexistent shared string '%s'%s
363 (S internal) Perl maintains a reference-counted internal table of
364 strings to optimize the storage and access of hash keys and other
365 strings. This indicates someone tried to decrement the reference count
366 of a string that can no longer be found in the table.
368 =item Attempt to free temp prematurely: SV 0x%x
370 (S debugging) Mortalized values are supposed to be freed by the
371 free_tmps() routine. This indicates that something else is freeing the
372 SV before the free_tmps() routine gets a chance, which means that the
373 free_tmps() routine will be freeing an unreferenced scalar when it does
376 =item Attempt to free unreferenced glob pointers
378 (S internal) The reference counts got screwed up on symbol aliases.
380 =item Attempt to free unreferenced scalar: SV 0x%x
382 (S internal) Perl went to decrement the reference count of a scalar to
383 see if it would go to 0, and discovered that it had already gone to 0
384 earlier, and should have been freed, and in fact, probably was freed.
385 This could indicate that SvREFCNT_dec() was called too many times, or
386 that SvREFCNT_inc() was called too few times, or that the SV was
387 mortalized when it shouldn't have been, or that memory has been
390 =item Attempt to pack pointer to temporary value
392 (W pack) You tried to pass a temporary value (like the result of a
393 function, or a computed expression) to the "p" pack() template. This
394 means the result contains a pointer to a location that could become
395 invalid anytime, even before the end of the current statement. Use
396 literals or global values as arguments to the "p" pack() template to
399 =item Attempt to reload %s aborted.
401 (F) You tried to load a file with C<use> or C<require> that failed to
402 compile once already. Perl will not try to compile this file again
403 unless you delete its entry from %INC. See L<perlfunc/require> and
406 =item Attempt to set length of freed array
408 (W misc) You tried to set the length of an array which has
409 been freed. You can do this by storing a reference to the
410 scalar representing the last index of an array and later
411 assigning through that reference. For example
413 $r = do {my @a; \$#a};
416 =item Attempt to use reference as lvalue in substr
418 (W substr) You supplied a reference as the first argument to substr()
419 used as an lvalue, which is pretty strange. Perhaps you forgot to
420 dereference it first. See L<perlfunc/substr>.
422 =item Attribute prototype(%s) discards earlier prototype attribute in same sub
424 (W misc) A sub was declared as sub foo : prototype(A) : prototype(B) {}, for
425 example. Since each sub can only have one prototype, the earlier
426 declaration(s) are discarded while the last one is applied.
428 =item av_reify called on tied array
430 (S debugging) This indicates that something went wrong and Perl got I<very>
431 confused about C<@_> or C<@DB::args> being tied.
433 =item Bad arg length for %s, is %u, should be %d
435 (F) You passed a buffer of the wrong size to one of msgctl(), semctl()
436 or shmctl(). In C parlance, the correct sizes are, respectively,
437 S<sizeof(struct msqid_ds *)>, S<sizeof(struct semid_ds *)>, and
438 S<sizeof(struct shmid_ds *)>.
440 =item Bad evalled substitution pattern
442 (F) You've used the C</e> switch to evaluate the replacement for a
443 substitution, but perl found a syntax error in the code to evaluate,
444 most likely an unexpected right brace '}'.
446 =item Bad filehandle: %s
448 (F) A symbol was passed to something wanting a filehandle, but the
449 symbol has no filehandle associated with it. Perhaps you didn't do an
450 open(), or did it in another package.
452 =item Bad free() ignored
454 (S malloc) An internal routine called free() on something that had never
455 been malloc()ed in the first place. Mandatory, but can be disabled by
456 setting environment variable C<PERL_BADFREE> to 0.
458 This message can be seen quite often with DB_File on systems with "hard"
459 dynamic linking, like C<AIX> and C<OS/2>. It is a bug of C<Berkeley DB>
460 which is left unnoticed if C<DB> uses I<forgiving> system malloc().
464 (P) One of the internal hash routines was passed a null HV pointer.
466 =item Badly placed ()'s
468 (A) You've accidentally run your script through B<csh> instead
469 of Perl. Check the #! line, or manually feed your script into
472 =item Bad name after %s
474 (F) You started to name a symbol by using a package prefix, and then
475 didn't finish the symbol. In particular, you can't interpolate outside
484 $sym = "mypack::$var";
486 =item Bad plugin affecting keyword '%s'
488 (F) An extension using the keyword plugin mechanism violated the
491 =item Bad realloc() ignored
493 (S malloc) An internal routine called realloc() on something that
494 had never been malloc()ed in the first place. Mandatory, but can
495 be disabled by setting the environment variable C<PERL_BADFREE> to 1.
497 =item Bad symbol for array
499 (P) An internal request asked to add an array entry to something that
500 wasn't a symbol table entry.
502 =item Bad symbol for dirhandle
504 (P) An internal request asked to add a dirhandle entry to something
505 that wasn't a symbol table entry.
507 =item Bad symbol for filehandle
509 (P) An internal request asked to add a filehandle entry to something
510 that wasn't a symbol table entry.
512 =item Bad symbol for hash
514 (P) An internal request asked to add a hash entry to something that
515 wasn't a symbol table entry.
517 =item Bad symbol for scalar
519 (P) An internal request asked to add a scalar entry to something that
520 wasn't a symbol table entry.
522 =item Bareword found in conditional
524 (W bareword) The compiler found a bareword where it expected a
525 conditional, which often indicates that an || or && was parsed as part
526 of the last argument of the previous construct, for example:
530 It may also indicate a misspelled constant that has been interpreted as
533 use constant TYPO => 1;
534 if (TYOP) { print "foo" }
536 The C<strict> pragma is useful in avoiding such errors.
538 =item Bareword in require contains "%s"
540 =item Bareword in require maps to disallowed filename "%s"
542 =item Bareword in require maps to empty filename
544 (F) The bareword form of require has been invoked with a filename which could
545 not have been generated by a valid bareword permitted by the parser. You
546 shouldn't be able to get this error from Perl code, but XS code may throw it
547 if it passes an invalid module name to C<Perl_load_module>.
549 =item Bareword in require must not start with a double-colon: "%s"
551 (F) In C<require Bare::Word>, the bareword is not allowed to start with a
552 double-colon. Write C<require ::Foo::Bar> as C<require Foo::Bar> instead.
554 =item Bareword "%s" not allowed while "strict subs" in use
556 (F) With "strict subs" in use, a bareword is only allowed as a
557 subroutine identifier, in curly brackets or to the left of the "=>"
558 symbol. Perhaps you need to predeclare a subroutine?
560 =item Bareword "%s" refers to nonexistent package
562 (W bareword) You used a qualified bareword of the form C<Foo::>, but the
563 compiler saw no other uses of that namespace before that point. Perhaps
564 you need to predeclare a package?
566 =item BEGIN failed--compilation aborted
568 (F) An untrapped exception was raised while executing a BEGIN
569 subroutine. Compilation stops immediately and the interpreter is
572 =item BEGIN not safe after errors--compilation aborted
574 (F) Perl found a C<BEGIN {}> subroutine (or a C<use> directive, which
575 implies a C<BEGIN {}>) after one or more compilation errors had already
576 occurred. Since the intended environment for the C<BEGIN {}> could not
577 be guaranteed (due to the errors), and since subsequent code likely
578 depends on its correct operation, Perl just gave up.
580 =item \%d better written as $%d
582 (W syntax) Outside of patterns, backreferences live on as variables.
583 The use of backslashes is grandfathered on the right-hand side of a
584 substitution, but stylistically it's better to use the variable form
585 because other Perl programmers will expect it, and it works better if
586 there are more than 9 backreferences.
588 =item Binary number > 0b11111111111111111111111111111111 non-portable
590 (W portable) The binary number you specified is larger than 2**32-1
591 (4294967295) and therefore non-portable between systems. See
592 L<perlport> for more on portability concerns.
594 =item bind() on closed socket %s
596 (W closed) You tried to do a bind on a closed socket. Did you forget to
597 check the return value of your socket() call? See L<perlfunc/bind>.
599 =item binmode() on closed filehandle %s
601 (W unopened) You tried binmode() on a filehandle that was never opened.
602 Check your control flow and number of arguments.
604 =item Bit vector size > 32 non-portable
606 (W portable) Using bit vector sizes larger than 32 is non-portable.
608 =item Bizarre copy of %s
610 (P) Perl detected an attempt to copy an internal value that is not
613 =item Bizarre SvTYPE [%d]
615 (P) When starting a new thread or returning values from a thread, Perl
616 encountered an invalid data type.
618 =item Both or neither range ends should be Unicode in regex; marked by
621 (W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
623 In a bracketed character class in a regular expression pattern, you
624 had a range which has exactly one end of it specified using C<\N{}>, and
625 the other end is specified using a non-portable mechanism. Perl treats
626 the range as a Unicode range, that is, all the characters in it are
627 considered to be the Unicode characters, and which may be different code
628 points on some platforms Perl runs on. For example, C<[\N{U+06}-\x08]>
629 is treated as if you had instead said C<[\N{U+06}-\N{U+08}]>, that is it
630 matches the characters whose code points in Unicode are 6, 7, and 8.
631 But that C<\x08> might indicate that you meant something different, so
632 the warning gets raised.
634 =item Buffer overflow in prime_env_iter: %s
636 (W internal) A warning peculiar to VMS. While Perl was preparing to
637 iterate over %ENV, it encountered a logical name or symbol definition
638 which was too long, so it was truncated to the string shown.
640 =item Callback called exit
642 (F) A subroutine invoked from an external package via call_sv()
643 exited by calling exit.
645 =item %s() called too early to check prototype
647 (W prototype) You've called a function that has a prototype before the
648 parser saw a definition or declaration for it, and Perl could not check
649 that the call conforms to the prototype. You need to either add an
650 early prototype declaration for the subroutine in question, or move the
651 subroutine definition ahead of the call to get proper prototype
652 checking. Alternatively, if you are certain that you're calling the
653 function correctly, you may put an ampersand before the name to avoid
654 the warning. See L<perlsub>.
658 (F) You passed an invalid number (like an infinity or not-a-number) to C<chr>.
660 =item Cannot complete in-place edit of %s: %s
662 (F) Your perl script appears to have changed directory while
663 performing an in-place edit of a file specified by a relative path,
664 and your system doesn't include the directory relative POSIX functions
665 needed to handle that.
667 =item Cannot compress %f in pack
669 (F) You tried compressing an infinity or not-a-number as an unsigned
670 integer with BER, which makes no sense.
672 =item Cannot compress integer in pack
674 (F) An argument to pack("w",...) was too large to compress.
675 The BER compressed integer format can only be used with positive
676 integers, and you attempted to compress a very large number (> 1e308).
677 See L<perlfunc/pack>.
679 =item Cannot compress negative numbers in pack
681 (F) An argument to pack("w",...) was negative. The BER compressed integer
682 format can only be used with positive integers. See L<perlfunc/pack>.
684 =item Cannot convert a reference to %s to typeglob
686 (F) You manipulated Perl's symbol table directly, stored a reference
687 in it, then tried to access that symbol via conventional Perl syntax.
688 The access triggers Perl to autovivify that typeglob, but it there is
689 no legal conversion from that type of reference to a typeglob.
691 =item Cannot copy to %s
693 (P) Perl detected an attempt to copy a value to an internal type that cannot
694 be directly assigned to.
696 =item Cannot find encoding "%s"
698 (S io) You tried to apply an encoding that did not exist to a filehandle,
699 either with open() or binmode().
701 =item Cannot open %s as a dirhandle: it is already open as a filehandle
703 (F) You tried to use opendir() to associate a dirhandle to a symbol (glob
704 or scalar) that already holds a filehandle. Since this idiom might render
705 your code confusing, it was deprecated in Perl 5.10. As of Perl 5.28, it
708 =item Cannot open %s as a filehandle: it is already open as a dirhandle
710 (F) You tried to use open() to associate a filehandle to a symbol (glob
711 or scalar) that already holds a dirhandle. Since this idiom might render
712 your code confusing, it was deprecated in Perl 5.10. As of Perl 5.28, it
715 =item Cannot pack %f with '%c'
717 (F) You tried converting an infinity or not-a-number to an integer,
718 which makes no sense.
720 =item Cannot printf %f with '%c'
722 (F) You tried printing an infinity or not-a-number as a character (%c),
723 which makes no sense. Maybe you meant '%s', or just stringifying it?
725 =item Cannot set tied @DB::args
727 (F) C<caller> tried to set C<@DB::args>, but found it tied. Tying C<@DB::args>
728 is not supported. (Before this error was added, it used to crash.)
730 =item Cannot tie unreifiable array
732 (P) You somehow managed to call C<tie> on an array that does not
733 keep a reference count on its arguments and cannot be made to
734 do so. Such arrays are not even supposed to be accessible to
735 Perl code, but are only used internally.
737 =item Cannot yet reorder sv_vcatpvfn() arguments from va_list
739 (F) Some XS code tried to use C<sv_vcatpvfn()> or a related function with a
740 format string that specifies explicit indexes for some of the elements, and
741 using a C-style variable-argument list (a C<va_list>). This is not currently
742 supported. XS authors wanting to do this must instead construct a C array
743 of C<SV*> scalars containing the arguments.
745 =item Can only compress unsigned integers in pack
747 (F) An argument to pack("w",...) was not an integer. The BER compressed
748 integer format can only be used with positive integers, and you attempted
749 to compress something else. See L<perlfunc/pack>.
751 =item Can't bless non-reference value
753 (F) Only hard references may be blessed. This is how Perl "enforces"
754 encapsulation of objects. See L<perlobj>.
756 =item Can't "break" in a loop topicalizer
758 (F) You called C<break>, but you're in a C<foreach> block rather than
759 a C<given> block. You probably meant to use C<next> or C<last>.
761 =item Can't "break" outside a given block
763 (F) You called C<break>, but you're not inside a C<given> block.
765 =item Can't call method "%s" on an undefined value
767 (F) You used the syntax of a method call, but the slot filled by the
768 object reference or package name contains an undefined value. Something
769 like this will reproduce the error:
772 process $BADREF 1,2,3;
773 $BADREF->process(1,2,3);
775 =item Can't call method "%s" on unblessed reference
777 (F) A method call must know in what package it's supposed to run. It
778 ordinarily finds this out from the object reference you supply, but you
779 didn't supply an object reference in this case. A reference isn't an
780 object reference until it has been blessed. See L<perlobj>.
782 =item Can't call method "%s" without a package or object reference
784 (F) You used the syntax of a method call, but the slot filled by the
785 object reference or package name contains an expression that returns a
786 defined value which is neither an object reference nor a package name.
787 Something like this will reproduce the error:
790 process $BADREF 1,2,3;
791 $BADREF->process(1,2,3);
793 =item Can't call mro_isa_changed_in() on anonymous symbol table
795 (P) Perl got confused as to whether a hash was a plain hash or a
796 symbol table hash when trying to update @ISA caches.
798 =item Can't call mro_method_changed_in() on anonymous symbol table
800 (F) An XS module tried to call C<mro_method_changed_in> on a hash that was
801 not attached to the symbol table.
803 =item Can't chdir to %s
805 (F) You called C<perl -x/foo/bar>, but F</foo/bar> is not a directory
806 that you can chdir to, possibly because it doesn't exist.
808 =item Can't check filesystem of script "%s" for nosuid
810 (P) For some reason you can't check the filesystem of the script for
813 =item Can't coerce %s to %s in %s
815 (F) Certain types of SVs, in particular real symbol table entries
816 (typeglobs), can't be forced to stop being what they are. So you can't
826 but then $foo no longer contains a glob.
828 =item Can't "continue" outside a when block
830 (F) You called C<continue>, but you're not inside a C<when>
833 =item Can't create pipe mailbox
835 (P) An error peculiar to VMS. The process is suffering from exhausted
836 quotas or other plumbing problems.
838 =item Can't declare %s in "%s"
840 (F) Only scalar, array, and hash variables may be declared as "my", "our" or
841 "state" variables. They must have ordinary identifiers as names.
843 =item Can't "default" outside a topicalizer
845 (F) You have used a C<default> block that is neither inside a
846 C<foreach> loop nor a C<given> block. (Note that this error is
847 issued on exit from the C<default> block, so you won't get the
848 error if you use an explicit C<continue>.)
850 =item Can't determine class of operator %s, assuming BASEOP
852 (S) This warning indicates something wrong in the internals of perl.
853 Perl was trying to find the class (e.g. LISTOP) of a particular OP,
854 and was unable to do so. This is likely to be due to a bug in the perl
855 internals, or due to a bug in XS code which manipulates perl optrees.
857 =item Can't do inplace edit: %s is not a regular file
859 (S inplace) You tried to use the B<-i> switch on a special file, such as
860 a file in /dev, a FIFO or an uneditable directory. The file was ignored.
862 =item Can't do inplace edit on %s: %s
864 (S inplace) The creation of the new file failed for the indicated
867 =item Can't do inplace edit: %s would not be unique
869 (S inplace) Your filesystem does not support filenames longer than 14
870 characters and Perl was unable to create a unique filename during
871 inplace editing with the B<-i> switch. The file was ignored.
873 =item Can't do %s("%s") on non-UTF-8 locale; resolved to "%s".
875 (W locale) You are 1) running under "C<use locale>"; 2) the current
876 locale is not a UTF-8 one; 3) you tried to do the designated case-change
877 operation on the specified Unicode character; and 4) the result of this
878 operation would mix Unicode and locale rules, which likely conflict.
879 Mixing of different rule types is forbidden, so the operation was not
880 done; instead the result is the indicated value, which is the best
881 available that uses entirely Unicode rules. That turns out to almost
882 always be the original character, unchanged.
884 It is generally a bad idea to mix non-UTF-8 locales and Unicode, and
885 this issue is one of the reasons why. This warning is raised when
886 Unicode rules would normally cause the result of this operation to
887 contain a character that is in the range specified by the locale,
888 0..255, and hence is subject to the locale's rules, not Unicode's.
890 If you are using locale purely for its characteristics related to things
891 like its numeric and time formatting (and not C<LC_CTYPE>), consider
892 using a restricted form of the locale pragma (see L<perllocale/The "use
893 locale" pragma>) like "S<C<use locale ':not_characters'>>".
895 Note that failed case-changing operations done as a result of
896 case-insensitive C</i> regular expression matching will show up in this
897 warning as having the C<fc> operation (as that is what the regular
898 expression engine calls behind the scenes.)
900 =item Can't do waitpid with flags
902 (F) This machine doesn't have either waitpid() or wait4(), so only
903 waitpid() without flags is emulated.
905 =item Can't emulate -%s on #! line
907 (F) The #! line specifies a switch that doesn't make sense at this
908 point. For example, it'd be kind of silly to put a B<-x> on the #!
911 =item Can't %s %s-endian %ss on this platform
913 (F) Your platform's byte-order is neither big-endian nor little-endian,
914 or it has a very strange pointer size. Packing and unpacking big- or
915 little-endian floating point values and pointers may not be possible.
916 See L<perlfunc/pack>.
918 =item Can't exec "%s": %s
920 (W exec) A system(), exec(), or piped open call could not execute the
921 named program for the indicated reason. Typical reasons include: the
922 permissions were wrong on the file, the file wasn't found in
923 C<$ENV{PATH}>, the executable in question was compiled for another
924 architecture, or the #! line in a script points to an interpreter that
925 can't be run for similar reasons. (Or maybe your system doesn't support
930 (F) Perl was trying to execute the indicated program for you because
931 that's what the #! line said. If that's not what you wanted, you may
932 need to mention "perl" on the #! line somewhere.
934 =item Can't execute %s
936 (F) You used the B<-S> switch, but the copies of the script to execute
937 found in the PATH did not have correct permissions.
939 =item Can't find an opnumber for "%s"
941 (F) A string of a form C<CORE::word> was given to prototype(), but there
942 is no builtin with the name C<word>.
944 =item Can't find label %s
946 (F) You said to goto a label that isn't mentioned anywhere that it's
947 possible for us to go to. See L<perlfunc/goto>.
949 =item Can't find %s on PATH
951 (F) You used the B<-S> switch, but the script to execute could not be
954 =item Can't find %s on PATH, '.' not in PATH
956 (F) You used the B<-S> switch, but the script to execute could not be
957 found in the PATH, or at least not with the correct permissions. The
958 script exists in the current directory, but PATH prohibits running it.
960 =item Can't find string terminator %s anywhere before EOF
962 (F) Perl strings can stretch over multiple lines. This message means
963 that the closing delimiter was omitted. Because bracketed quotes count
964 nesting levels, the following is missing its final parenthesis:
966 print q(The character '(' starts a side comment.);
968 If you're getting this error from a here-document, you may have
969 included unseen whitespace before or after your closing tag or there
970 may not be a linebreak after it. A good programmer's editor will have
971 a way to help you find these characters (or lack of characters). See
972 L<perlop> for the full details on here-documents.
974 =item Can't find Unicode property definition "%s"
976 =item Can't find Unicode property definition "%s" in regex; marked by <-- HERE in m/%s/
978 (F) The named property which you specified via C<\p> or C<\P> is not one
979 known to Perl. Perhaps you misspelled the name? See
980 L<perluniprops/Properties accessible through \p{} and \P{}>
981 for a complete list of available official
982 properties. If it is a
983 L<user-defined property|perlunicode/User-Defined Character Properties>
984 it must have been defined by the time the regular expression is
987 If you didn't mean to use a Unicode property, escape the C<\p>, either
988 by C<\\p> (just the C<\p>) or by C<\Q\p> (the rest of the string, or
993 (F) A fatal error occurred while trying to fork while opening a
996 =item Can't fork, trying again in 5 seconds
998 (W pipe) A fork in a piped open failed with EAGAIN and will be retried
1001 =item Can't get filespec - stale stat buffer?
1003 (S) A warning peculiar to VMS. This arises because of the difference
1004 between access checks under VMS and under the Unix model Perl assumes.
1005 Under VMS, access checks are done by filename, rather than by bits in
1006 the stat buffer, so that ACLs and other protections can be taken into
1007 account. Unfortunately, Perl assumes that the stat buffer contains all
1008 the necessary information, and passes it, instead of the filespec, to
1009 the access-checking routine. It will try to retrieve the filespec using
1010 the device name and FID present in the stat buffer, but this works only
1011 if you haven't made a subsequent call to the CRTL stat() routine,
1012 because the device name is overwritten with each call. If this warning
1013 appears, the name lookup failed, and the access-checking routine gave up
1014 and returned FALSE, just to be conservative. (Note: The access-checking
1015 routine knows about the Perl C<stat> operator and file tests, so you
1016 shouldn't ever see this warning in response to a Perl command; it arises
1017 only if some internal code takes stat buffers lightly.)
1019 =item Can't get pipe mailbox device name
1021 (P) An error peculiar to VMS. After creating a mailbox to act as a
1022 pipe, Perl can't retrieve its name for later use.
1024 =item Can't get SYSGEN parameter value for MAXBUF
1026 (P) An error peculiar to VMS. Perl asked $GETSYI how big you want your
1027 mailbox buffers to be, and didn't get an answer.
1029 =item Can't "goto" into a binary or list expression
1031 (F) A "goto" statement was executed to jump into the middle of a binary
1032 or list expression. You can't get there from here. The reason for this
1033 restriction is that the interpreter would get confused as to how many
1034 arguments there are, resulting in stack corruption or crashes. This
1035 error occurs in cases such as these:
1038 print do { F: }; # Can't jump into the arguments to print
1041 $x + do { G: $y }; # How is + supposed to get its first operand?
1043 =item Can't "goto" into a "given" block
1045 (F) A "goto" statement was executed to jump into the middle of a C<given>
1046 block. You can't get there from here. See L<perlfunc/goto>.
1048 =item Can't "goto" into the middle of a foreach loop
1050 (F) A "goto" statement was executed to jump into the middle of a foreach
1051 loop. You can't get there from here. See L<perlfunc/goto>.
1053 =item Can't "goto" out of a pseudo block
1055 (F) A "goto" statement was executed to jump out of what might look like
1056 a block, except that it isn't a proper block. This usually occurs if
1057 you tried to jump out of a sort() block or subroutine, which is a no-no.
1058 See L<perlfunc/goto>.
1060 =item Can't goto subroutine from an eval-%s
1062 (F) The "goto subroutine" call can't be used to jump out of an eval
1065 =item Can't goto subroutine from a sort sub (or similar callback)
1067 (F) The "goto subroutine" call can't be used to jump out of the
1068 comparison sub for a sort(), or from a similar callback (such
1069 as the reduce() function in List::Util).
1071 =item Can't goto subroutine outside a subroutine
1073 (F) The deeply magical "goto subroutine" call can only replace one
1074 subroutine call for another. It can't manufacture one out of whole
1075 cloth. In general you should be calling it out of only an AUTOLOAD
1076 routine anyway. See L<perlfunc/goto>.
1078 =item Can't ignore signal CHLD, forcing to default
1080 (W signal) Perl has detected that it is being run with the SIGCHLD
1081 signal (sometimes known as SIGCLD) disabled. Since disabling this
1082 signal will interfere with proper determination of exit status of child
1083 processes, Perl has reset the signal to its default value. This
1084 situation typically indicates that the parent program under which Perl
1085 may be running (e.g. cron) is being very careless.
1087 =item Can't kill a non-numeric process ID
1089 (F) Process identifiers must be (signed) integers. It is a fatal error to
1090 attempt to kill() an undefined, empty-string or otherwise non-numeric
1093 =item Can't "last" outside a loop block
1095 (F) A "last" statement was executed to break out of the current block,
1096 except that there's this itty bitty problem called there isn't a current
1097 block. Note that an "if" or "else" block doesn't count as a "loopish"
1098 block, as doesn't a block given to sort(), map() or grep(). You can
1099 usually double the curlies to get the same effect though, because the
1100 inner curlies will be considered a block that loops once. See
1103 =item Can't linearize anonymous symbol table
1105 (F) Perl tried to calculate the method resolution order (MRO) of a
1106 package, but failed because the package stash has no name.
1108 =item Can't load '%s' for module %s
1110 (F) The module you tried to load failed to load a dynamic extension.
1111 This may either mean that you upgraded your version of perl to one
1112 that is incompatible with your old dynamic extensions (which is known
1113 to happen between major versions of perl), or (more likely) that your
1114 dynamic extension was built against an older version of the library
1115 that is installed on your system. You may need to rebuild your old
1118 =item Can't localize lexical variable %s
1120 (F) You used local on a variable name that was previously declared as a
1121 lexical variable using "my" or "state". This is not allowed. If you
1122 want to localize a package variable of the same name, qualify it with
1125 =item Can't localize through a reference
1127 (F) You said something like C<local $$ref>, which Perl can't currently
1128 handle, because when it goes to restore the old value of whatever $ref
1129 pointed to after the scope of the local() is finished, it can't be sure
1130 that $ref will still be a reference.
1132 =item Can't locate %s
1134 (F) You said to C<do> (or C<require>, or C<use>) a file that couldn't be found.
1135 Perl looks for the file in all the locations mentioned in @INC, unless
1136 the file name included the full path to the file. Perhaps you need
1137 to set the PERL5LIB or PERL5OPT environment variable to say where the
1138 extra library is, or maybe the script needs to add the library name
1139 to @INC. Or maybe you just misspelled the name of the file. See
1140 L<perlfunc/require> and L<lib>.
1142 =item Can't locate auto/%s.al in @INC
1144 (F) A function (or method) was called in a package which allows
1145 autoload, but there is no function to autoload. Most probable causes
1146 are a misprint in a function/method name or a failure to C<AutoSplit>
1147 the file, say, by doing C<make install>.
1149 =item Can't locate loadable object for module %s in @INC
1151 (F) The module you loaded is trying to load an external library, like
1152 for example, F<foo.so> or F<bar.dll>, but the L<DynaLoader> module was
1153 unable to locate this library. See L<DynaLoader>.
1155 =item Can't locate object method "%s" via package "%s"
1157 (F) You called a method correctly, and it correctly indicated a package
1158 functioning as a class, but that package doesn't define that particular
1159 method, nor does any of its base classes. See L<perlobj>.
1161 =item Can't locate object method "%s" via package "%s" (perhaps you forgot
1164 (F) You called a method on a class that did not exist, and the method
1165 could not be found in UNIVERSAL. This often means that a method
1166 requires a package that has not been loaded.
1168 =item Can't locate package %s for @%s::ISA
1170 (W syntax) The @ISA array contained the name of another package that
1171 doesn't seem to exist.
1173 =item Can't locate PerlIO%s
1175 (F) You tried to use in open() a PerlIO layer that does not exist,
1176 e.g. open(FH, ">:nosuchlayer", "somefile").
1178 =item Can't make list assignment to %ENV on this system
1180 (F) List assignment to %ENV is not supported on some systems, notably
1183 =item Can't make loaded symbols global on this platform while loading %s
1185 (S) A module passed the flag 0x01 to DynaLoader::dl_load_file() to request
1186 that symbols from the stated file are made available globally within the
1187 process, but that functionality is not available on this platform. Whilst
1188 the module likely will still work, this may prevent the perl interpreter
1189 from loading other XS-based extensions which need to link directly to
1190 functions defined in the C or XS code in the stated file.
1192 =item Can't modify %s in %s
1194 (F) You aren't allowed to assign to the item indicated, or otherwise try
1195 to change it, such as with an auto-increment.
1197 =item Can't modify nonexistent substring
1199 (P) The internal routine that does assignment to a substr() was handed
1202 =item Can't modify non-lvalue subroutine call of &%s
1204 =item Can't modify non-lvalue subroutine call of &%s in %s
1206 (F) Subroutines meant to be used in lvalue context should be declared as
1207 such. See L<perlsub/"Lvalue subroutines">.
1209 =item Can't modify reference to %s in %s assignment
1211 (F) Only a limited number of constructs can be used as the argument to a
1212 reference constructor on the left-hand side of an assignment, and what
1213 you used was not one of them. See L<perlref/Assigning to References>.
1215 =item Can't modify reference to localized parenthesized array in list
1218 (F) Assigning to C<\local(@array)> or C<\(local @array)> is not supported, as
1219 it is not clear exactly what it should do. If you meant to make @array
1220 refer to some other array, use C<\@array = \@other_array>. If you want to
1221 make the elements of @array aliases of the scalars referenced on the
1222 right-hand side, use C<\(@array) = @scalar_refs>.
1224 =item Can't modify reference to parenthesized hash in list assignment
1226 (F) Assigning to C<\(%hash)> is not supported. If you meant to make %hash
1227 refer to some other hash, use C<\%hash = \%other_hash>. If you want to
1228 make the elements of %hash into aliases of the scalars referenced on the
1229 right-hand side, use a hash slice: C<\@hash{@keys} = @those_scalar_refs>.
1231 =item Can't msgrcv to read-only var
1233 (F) The target of a msgrcv must be modifiable to be used as a receive
1236 =item Can't "next" outside a loop block
1238 (F) A "next" statement was executed to reiterate the current block, but
1239 there isn't a current block. Note that an "if" or "else" block doesn't
1240 count as a "loopish" block, as doesn't a block given to sort(), map() or
1241 grep(). You can usually double the curlies to get the same effect
1242 though, because the inner curlies will be considered a block that loops
1243 once. See L<perlfunc/next>.
1245 =item Can't open %s: %s
1247 (S inplace) The implicit opening of a file through use of the C<< <> >>
1248 filehandle, either implicitly under the C<-n> or C<-p> command-line
1249 switches, or explicitly, failed for the indicated reason. Usually
1250 this is because you don't have read permission for a file which
1251 you named on the command line.
1253 (F) You tried to call perl with the B<-e> switch, but F</dev/null> (or
1254 your operating system's equivalent) could not be opened.
1256 =item Can't open a reference
1258 (W io) You tried to open a scalar reference for reading or writing,
1259 using the 3-arg open() syntax:
1263 but your version of perl is compiled without perlio, and this form of
1264 open is not supported.
1266 =item Can't open bidirectional pipe
1268 (W pipe) You tried to say C<open(CMD, "|cmd|")>, which is not supported.
1269 You can try any of several modules in the Perl library to do this, such
1270 as IPC::Open2. Alternately, direct the pipe's output to a file using
1271 ">", and then read it in under a different file handle.
1273 =item Can't open error file %s as stderr
1275 (F) An error peculiar to VMS. Perl does its own command line
1276 redirection, and couldn't open the file specified after '2>' or '2>>' on
1277 the command line for writing.
1279 =item Can't open input file %s as stdin
1281 (F) An error peculiar to VMS. Perl does its own command line
1282 redirection, and couldn't open the file specified after '<' on the
1283 command line for reading.
1285 =item Can't open output file %s as stdout
1287 (F) An error peculiar to VMS. Perl does its own command line
1288 redirection, and couldn't open the file specified after '>' or '>>' on
1289 the command line for writing.
1291 =item Can't open output pipe (name: %s)
1293 (P) An error peculiar to VMS. Perl does its own command line
1294 redirection, and couldn't open the pipe into which to send data destined
1297 =item Can't open perl script "%s": %s
1299 (F) The script you specified can't be opened for the indicated reason.
1301 If you're debugging a script that uses #!, and normally relies on the
1302 shell's $PATH search, the -S option causes perl to do that search, so
1303 you don't have to type the path or C<`which $scriptname`>.
1305 =item Can't read CRTL environ
1307 (S) A warning peculiar to VMS. Perl tried to read an element of %ENV
1308 from the CRTL's internal environment array and discovered the array was
1309 missing. You need to figure out where your CRTL misplaced its environ
1310 or define F<PERL_ENV_TABLES> (see L<perlvms>) so that environ is not
1313 =item Can't redeclare "%s" in "%s"
1315 (F) A "my", "our" or "state" declaration was found within another declaration,
1316 such as C<my ($x, my($y), $z)> or C<our (my $x)>.
1318 =item Can't "redo" outside a loop block
1320 (F) A "redo" statement was executed to restart the current block, but
1321 there isn't a current block. Note that an "if" or "else" block doesn't
1322 count as a "loopish" block, as doesn't a block given to sort(), map()
1323 or grep(). You can usually double the curlies to get the same effect
1324 though, because the inner curlies will be considered a block that
1325 loops once. See L<perlfunc/redo>.
1327 =item Can't remove %s: %s, skipping file
1329 (S inplace) You requested an inplace edit without creating a backup
1330 file. Perl was unable to remove the original file to replace it with
1331 the modified file. The file was left unmodified.
1333 =item Can't rename in-place work file '%s' to '%s': %s
1335 (F) When closed implicitly, the temporary file for in-place editing
1336 couldn't be renamed to the original filename.
1338 =item Can't rename %s to %s: %s, skipping file
1340 (F) The rename done by the B<-i> switch failed for some reason,
1341 probably because you don't have write permission to the directory.
1343 =item Can't reopen input pipe (name: %s) in binary mode
1345 (P) An error peculiar to VMS. Perl thought stdin was a pipe, and tried
1346 to reopen it to accept binary data. Alas, it failed.
1348 =item Can't represent character for Ox%X on this platform
1350 (F) There is a hard limit to how big a character code point can be due
1351 to the fundamental properties of UTF-8, especially on EBCDIC
1352 platforms. The given code point exceeds that. The only work-around is
1353 to not use such a large code point.
1355 =item Can't reset %ENV on this system
1357 (F) You called C<reset('E')> or similar, which tried to reset
1358 all variables in the current package beginning with "E". In
1359 the main package, that includes %ENV. Resetting %ENV is not
1360 supported on some systems, notably VMS.
1362 =item Can't resolve method "%s" overloading "%s" in package "%s"
1364 (F)(P) Error resolving overloading specified by a method name (as
1365 opposed to a subroutine reference): no such method callable via the
1366 package. If the method name is C<???>, this is an internal error.
1368 =item Can't return %s from lvalue subroutine
1370 (F) Perl detected an attempt to return illegal lvalues (such as
1371 temporary or readonly values) from a subroutine used as an lvalue. This
1374 =item Can't return outside a subroutine
1376 (F) The return statement was executed in mainline code, that is, where
1377 there was no subroutine call to return out of. See L<perlsub>.
1379 =item Can't return %s to lvalue scalar context
1381 (F) You tried to return a complete array or hash from an lvalue
1382 subroutine, but you called the subroutine in a way that made Perl
1383 think you meant to return only one value. You probably meant to
1384 write parentheses around the call to the subroutine, which tell
1385 Perl that the call should be in list context.
1387 =item Can't stat script "%s"
1389 (P) For some reason you can't fstat() the script even though you have it
1390 open already. Bizarre.
1392 =item Can't take log of %g
1394 (F) For ordinary real numbers, you can't take the logarithm of a
1395 negative number or zero. There's a Math::Complex package that comes
1396 standard with Perl, though, if you really want to do that for the
1399 =item Can't take sqrt of %g
1401 (F) For ordinary real numbers, you can't take the square root of a
1402 negative number. There's a Math::Complex package that comes standard
1403 with Perl, though, if you really want to do that.
1405 =item Can't undef active subroutine
1407 (F) You can't undefine a routine that's currently running. You can,
1408 however, redefine it while it's running, and you can even undef the
1409 redefined subroutine while the old routine is running. Go figure.
1411 =item Can't unweaken a nonreference
1413 (F) You attempted to unweaken something that was not a reference. Only
1414 references can be unweakened.
1416 =item Can't upgrade %s (%d) to %d
1418 (P) The internal sv_upgrade routine adds "members" to an SV, making it
1419 into a more specialized kind of SV. The top several SV types are so
1420 specialized, however, that they cannot be interconverted. This message
1421 indicates that such a conversion was attempted.
1423 =item Can't use '%c' after -mname
1425 (F) You tried to call perl with the B<-m> switch, but you put something
1426 other than "=" after the module name.
1428 =item Can't use a hash as a reference
1430 (F) You tried to use a hash as a reference, as in
1431 C<< %foo->{"bar"} >> or C<< %$ref->{"hello"} >>. Versions of perl
1432 <= 5.22.0 used to allow this syntax, but shouldn't
1433 have. This was deprecated in perl 5.6.1.
1435 =item Can't use an array as a reference
1437 (F) You tried to use an array as a reference, as in
1438 C<< @foo->[23] >> or C<< @$ref->[99] >>. Versions of perl <= 5.22.0
1439 used to allow this syntax, but shouldn't have. This
1440 was deprecated in perl 5.6.1.
1442 =item Can't use anonymous symbol table for method lookup
1444 (F) The internal routine that does method lookup was handed a symbol
1445 table that doesn't have a name. Symbol tables can become anonymous
1446 for example by undefining stashes: C<undef %Some::Package::>.
1448 =item Can't use an undefined value as %s reference
1450 (F) A value used as either a hard reference or a symbolic reference must
1451 be a defined value. This helps to delurk some insidious errors.
1453 =item Can't use bareword ("%s") as %s ref while "strict refs" in use
1455 (F) Only hard references are allowed by "strict refs". Symbolic
1456 references are disallowed. See L<perlref>.
1458 =item Can't use %! because Errno.pm is not available
1460 (F) The first time the C<%!> hash is used, perl automatically loads the
1461 Errno.pm module. The Errno module is expected to tie the %! hash to
1462 provide symbolic names for C<$!> errno values.
1464 =item Can't use both '<' and '>' after type '%c' in %s
1466 (F) A type cannot be forced to have both big-endian and little-endian
1467 byte-order at the same time, so this combination of modifiers is not
1468 allowed. See L<perlfunc/pack>.
1470 =item Can't use 'defined(@array)' (Maybe you should just omit the defined()?)
1472 (F) defined() is not useful on arrays because it
1473 checks for an undefined I<scalar> value. If you want to see if the
1474 array is empty, just use C<if (@array) { # not empty }> for example.
1476 =item Can't use 'defined(%hash)' (Maybe you should just omit the defined()?)
1478 (F) C<defined()> is not usually right on hashes.
1480 Although C<defined %hash> is false on a plain not-yet-used hash, it
1481 becomes true in several non-obvious circumstances, including iterators,
1482 weak references, stash names, even remaining true after C<undef %hash>.
1483 These things make C<defined %hash> fairly useless in practice, so it now
1484 generates a fatal error.
1486 If a check for non-empty is what you wanted then just put it in boolean
1487 context (see L<perldata/Scalar values>):
1493 If you had C<defined %Foo::Bar::QUUX> to check whether such a package
1494 variable exists then that's never really been reliable, and isn't
1495 a good way to enquire about the features of a package, or whether
1498 =item Can't use %s for loop variable
1500 (P) The parser got confused when trying to parse a C<foreach> loop.
1502 =item Can't use global %s in "%s"
1504 (F) You tried to declare a magical variable as a lexical variable. This
1505 is not allowed, because the magic can be tied to only one location
1506 (namely the global variable) and it would be incredibly confusing to
1507 have variables in your program that looked like magical variables but
1510 =item Can't use '%c' in a group with different byte-order in %s
1512 (F) You attempted to force a different byte-order on a type
1513 that is already inside a group with a byte-order modifier.
1514 For example you cannot force little-endianness on a type that
1515 is inside a big-endian group.
1517 =item Can't use "my %s" in sort comparison
1519 (F) The global variables $a and $b are reserved for sort comparisons.
1520 You mentioned $a or $b in the same line as the <=> or cmp operator,
1521 and the variable had earlier been declared as a lexical variable.
1522 Either qualify the sort variable with the package name, or rename the
1525 =item Can't use %s ref as %s ref
1527 (F) You've mixed up your reference types. You have to dereference a
1528 reference of the type needed. You can use the ref() function to
1529 test the type of the reference, if need be.
1531 =item Can't use string ("%s") as %s ref while "strict refs" in use
1533 =item Can't use string ("%s"...) as %s ref while "strict refs" in use
1535 (F) You've told Perl to dereference a string, something which
1536 C<use strict> blocks to prevent it happening accidentally. See
1537 L<perlref/"Symbolic references">. This can be triggered by an C<@> or C<$>
1538 in a double-quoted string immediately before interpolating a variable,
1539 for example in C<"user @$twitter_id">, which says to treat the contents
1540 of C<$twitter_id> as an array reference; use a C<\> to have a literal C<@>
1541 symbol followed by the contents of C<$twitter_id>: C<"user \@$twitter_id">.
1543 =item Can't use subscript on %s
1545 (F) The compiler tried to interpret a bracketed expression as a
1546 subscript. But to the left of the brackets was an expression that
1547 didn't look like a hash or array reference, or anything else subscriptable.
1549 =item Can't use \%c to mean $%c in expression
1551 (W syntax) In an ordinary expression, backslash is a unary operator that
1552 creates a reference to its argument. The use of backslash to indicate a
1553 backreference to a matched substring is valid only as part of a regular
1554 expression pattern. Trying to do this in ordinary Perl code produces a
1555 value that prints out looking like SCALAR(0xdecaf). Use the $1 form
1558 =item Can't weaken a nonreference
1560 (F) You attempted to weaken something that was not a reference. Only
1561 references can be weakened.
1563 =item Can't "when" outside a topicalizer
1565 (F) You have used a when() block that is neither inside a C<foreach>
1566 loop nor a C<given> block. (Note that this error is issued on exit
1567 from the C<when> block, so you won't get the error if the match fails,
1568 or if you use an explicit C<continue>.)
1570 =item Can't x= to read-only value
1572 (F) You tried to repeat a constant value (often the undefined value)
1573 with an assignment operator, which implies modifying the value itself.
1574 Perhaps you need to copy the value to a temporary, and repeat that.
1576 =item Character following "\c" must be printable ASCII
1578 (F) In C<\cI<X>>, I<X> must be a printable (non-control) ASCII character.
1580 Note that ASCII characters that don't map to control characters are
1581 discouraged, and will generate the warning (when enabled)
1582 L</""\c%c" is more clearly written simply as "%s"">.
1584 =item Character following \%c must be '{' or a single-character Unicode property name in regex; marked by <-- HERE in m/%s/
1586 (F) (In the above the C<%c> is replaced by either C<p> or C<P>.) You
1587 specified something that isn't a legal Unicode property name. Most
1588 Unicode properties are specified by C<\p{...}>. But if the name is a
1589 single character one, the braces may be omitted.
1591 =item Character in 'C' format wrapped in pack
1597 where $x is either less than 0 or more than 255; the C<"C"> format is
1598 only for encoding native operating system characters (ASCII, EBCDIC,
1599 and so on) and not for Unicode characters, so Perl behaved as if you meant
1603 If you actually want to pack Unicode codepoints, use the C<"U"> format
1606 =item Character in 'c' format wrapped in pack
1612 where $x is either less than -128 or more than 127; the C<"c"> format
1613 is only for encoding native operating system characters (ASCII, EBCDIC,
1614 and so on) and not for Unicode characters, so Perl behaved as if you meant
1616 pack("c", $x & 255);
1618 If you actually want to pack Unicode codepoints, use the C<"U"> format
1621 =item Character in '%c' format wrapped in unpack
1623 (W unpack) You tried something like
1625 unpack("H", "\x{2a1}")
1627 where the format expects to process a byte (a character with a value
1628 below 256), but a higher value was provided instead. Perl uses the
1629 value modulus 256 instead, as if you had provided:
1631 unpack("H", "\x{a1}")
1633 =item Character in 'W' format wrapped in pack
1639 where $x is either less than 0 or more than 255. However, C<U0>-mode
1640 expects all values to fall in the interval [0, 255], so Perl behaved
1643 pack("U0W", $x & 255)
1645 =item Character(s) in '%c' format wrapped in pack
1647 (W pack) You tried something like
1649 pack("u", "\x{1f3}b")
1651 where the format expects to process a sequence of bytes (character with a
1652 value below 256), but some of the characters had a higher value. Perl
1653 uses the character values modulus 256 instead, as if you had provided:
1655 pack("u", "\x{f3}b")
1657 =item Character(s) in '%c' format wrapped in unpack
1659 (W unpack) You tried something like
1661 unpack("s", "\x{1f3}b")
1663 where the format expects to process a sequence of bytes (character with a
1664 value below 256), but some of the characters had a higher value. Perl
1665 uses the character values modulus 256 instead, as if you had provided:
1667 unpack("s", "\x{f3}b")
1669 =item charnames alias definitions may not contain a sequence of multiple
1670 spaces; marked by S<<-- HERE> in %s
1672 (F) You defined a character name which had multiple space characters
1673 in a row. Change them to single spaces. Usually these names are
1674 defined in the C<:alias> import argument to C<use charnames>, but they
1675 could be defined by a translator installed into C<$^H{charnames}>. See
1676 L<charnames/CUSTOM ALIASES>.
1678 =item charnames alias definitions may not contain trailing white-space;
1679 marked by S<<-- HERE> in %s
1681 (F) You defined a character name which ended in a space
1682 character. Remove the trailing space(s). Usually these names are
1683 defined in the C<:alias> import argument to C<use charnames>, but they
1684 could be defined by a translator installed into C<$^H{charnames}>.
1685 See L<charnames/CUSTOM ALIASES>.
1687 =item chdir() on unopened filehandle %s
1689 (W unopened) You tried chdir() on a filehandle that was never opened.
1691 =item "\c%c" is more clearly written simply as "%s"
1693 (W syntax) The C<\cI<X>> construct is intended to be a way to specify
1694 non-printable characters. You used it for a printable one, which
1695 is better written as simply itself, perhaps preceded by a backslash
1696 for non-word characters. Doing it the way you did is not portable
1697 between ASCII and EBCDIC platforms.
1699 =item Cloning substitution context is unimplemented
1701 (F) Creating a new thread inside the C<s///> operator is not supported.
1703 =item closedir() attempted on invalid dirhandle %s
1705 (W io) The dirhandle you tried to close is either closed or not really
1706 a dirhandle. Check your control flow.
1708 =item close() on unopened filehandle %s
1710 (W unopened) You tried to close a filehandle that was never opened.
1712 =item Closure prototype called
1714 (F) If a closure has attributes, the subroutine passed to an attribute
1715 handler is the prototype that is cloned when a new closure is created.
1716 This subroutine cannot be called.
1718 =item \C no longer supported in regex; marked by S<<-- HERE> in m/%s/
1720 (F) The \C character class used to allow a match of single byte
1721 within a multi-byte utf-8 character, but was removed in v5.24 as
1722 it broke encapsulation and its implementation was extremely buggy.
1723 If you really need to process the individual bytes, you probably
1724 want to convert your string to one where each underlying byte is
1725 stored as a character, with utf8::encode().
1727 =item Code missing after '/'
1729 (F) You had a (sub-)template that ends with a '/'. There must be
1730 another template code following the slash. See L<perlfunc/pack>.
1732 =item Code point 0x%X is not Unicode, and not portable
1734 (S non_unicode) You had a code point that has never been in any
1735 standard, so it is likely that languages other than Perl will NOT
1736 understand it. At one time, it was legal in some standards to have code
1737 points up to 0x7FFF_FFFF, but not higher, and this code point is higher.
1739 Acceptance of these code points is a Perl extension, and you should
1740 expect that nothing other than Perl can handle them; Perl itself on
1741 EBCDIC platforms before v5.24 does not handle them.
1743 Code points above 0xFFFF_FFFF require larger than a 32 bit word.
1745 Perl also makes no guarantees that the representation of these code
1746 points won't change at some point in the future, say when machines
1747 become available that have larger than a 64-bit word. At that time,
1748 files written by an older Perl would require conversion before being
1749 readable by a newer Perl.
1751 =item Code point 0x%X is not Unicode, may not be portable
1753 (S non_unicode) You had a code point above the Unicode maximum
1756 Perl allows strings to contain a superset of Unicode code points, but
1757 these may not be accepted by other languages/systems. Further, even if
1758 these languages/systems accept these large code points, they may have
1759 chosen a different representation for them than the UTF-8-like one that
1760 Perl has, which would mean files are not exchangeable between them and
1763 On EBCDIC platforms, code points above 0x3FFF_FFFF have a different
1764 representation in Perl v5.24 than before, so any file containing these
1765 that was written before that version will require conversion before
1766 being readable by a later Perl.
1768 =item %s: Command not found
1770 (A) You've accidentally run your script through B<csh> or another shell
1771 instead of Perl. Check the #! line, or manually feed your script into
1772 Perl yourself. The #! line at the top of your file could look like
1776 =item %s: command not found
1778 (A) You've accidentally run your script through B<bash> or another shell
1779 instead of Perl. Check the #! line, or manually feed your script into
1780 Perl yourself. The #! line at the top of your file could look like
1784 =item %s: command not found: %s
1786 (A) You've accidentally run your script through B<zsh> or another shell
1787 instead of Perl. Check the #! line, or manually feed your script into
1788 Perl yourself. The #! line at the top of your file could look like
1792 =item Compilation failed in require
1794 (F) Perl could not compile a file specified in a C<require> statement.
1795 Perl uses this generic message when none of the errors that it
1796 encountered were severe enough to halt compilation immediately.
1798 =item Complex regular subexpression recursion limit (%d) exceeded
1800 (W regexp) The regular expression engine uses recursion in complex
1801 situations where back-tracking is required. Recursion depth is limited
1802 to 32766, or perhaps less in architectures where the stack cannot grow
1803 arbitrarily. ("Simple" and "medium" situations are handled without
1804 recursion and are not subject to a limit.) Try shortening the string
1805 under examination; looping in Perl code (e.g. with C<while>) rather than
1806 in the regular expression engine; or rewriting the regular expression so
1807 that it is simpler or backtracks less. (See L<perlfaq2> for information
1808 on I<Mastering Regular Expressions>.)
1810 =item connect() on closed socket %s
1812 (W closed) You tried to do a connect on a closed socket. Did you forget
1813 to check the return value of your socket() call? See
1814 L<perlfunc/connect>.
1816 =item Constant(%s): Call to &{$^H{%s}} did not return a defined value
1818 (F) The subroutine registered to handle constant overloading
1819 (see L<overload>) or a custom charnames handler (see
1820 L<charnames/CUSTOM TRANSLATORS>) returned an undefined value.
1822 =item Constant(%s): $^H{%s} is not defined
1824 (F) The parser found inconsistencies while attempting to define an
1825 overloaded constant. Perhaps you forgot to load the corresponding
1828 =item Constant is not %s reference
1830 (F) A constant value (perhaps declared using the C<use constant> pragma)
1831 is being dereferenced, but it amounts to the wrong type of reference.
1832 The message indicates the type of reference that was expected. This
1833 usually indicates a syntax error in dereferencing the constant value.
1834 See L<perlsub/"Constant Functions"> and L<constant>.
1836 =item Constants from lexical variables potentially modified elsewhere are
1837 deprecated. This will not be allowed in Perl 5.32
1839 (D deprecated) You wrote something like
1842 $sub = sub () { $var };
1844 but $var is referenced elsewhere and could be modified after the C<sub>
1845 expression is evaluated. Either it is explicitly modified elsewhere
1846 (C<$var = 3>) or it is passed to a subroutine or to an operator like
1847 C<printf> or C<map>, which may or may not modify the variable.
1849 Traditionally, Perl has captured the value of the variable at that
1850 point and turned the subroutine into a constant eligible for inlining.
1851 In those cases where the variable can be modified elsewhere, this
1852 breaks the behavior of closures, in which the subroutine captures
1853 the variable itself, rather than its value, so future changes to the
1854 variable are reflected in the subroutine's return value.
1856 This usage is deprecated, and will no longer be allowed in Perl 5.32,
1857 making it possible to change the behavior in the future.
1859 If you intended for the subroutine to be eligible for inlining, then
1860 make sure the variable is not referenced elsewhere, possibly by
1864 $sub = sub () { $var2 };
1866 If you do want this subroutine to be a closure that reflects future
1867 changes to the variable that it closes over, add an explicit C<return>:
1870 $sub = sub () { return $var };
1872 =item Constant subroutine %s redefined
1874 (W redefine)(S) You redefined a subroutine which had previously
1875 been eligible for inlining. See L<perlsub/"Constant Functions">
1876 for commentary and workarounds.
1878 =item Constant subroutine %s undefined
1880 (W misc) You undefined a subroutine which had previously been eligible
1881 for inlining. See L<perlsub/"Constant Functions"> for commentary and
1884 =item Constant(%s) unknown
1886 (F) The parser found inconsistencies either while attempting
1887 to define an overloaded constant, or when trying to find the
1888 character name specified in the C<\N{...}> escape. Perhaps you
1889 forgot to load the corresponding L<overload> pragma?
1891 =item :const is experimental
1893 (S experimental::const_attr) The "const" attribute is experimental.
1894 If you want to use the feature, disable the warning with C<no warnings
1895 'experimental::const_attr'>, but know that in doing so you are taking
1896 the risk that your code may break in a future Perl version.
1898 =item :const is not permitted on named subroutines
1900 (F) The "const" attribute causes an anonymous subroutine to be run and
1901 its value captured at the time that it is cloned. Named subroutines are
1902 not cloned like this, so the attribute does not make sense on them.
1904 =item Copy method did not return a reference
1906 (F) The method which overloads "=" is buggy. See
1907 L<overload/Copy Constructor>.
1909 =item &CORE::%s cannot be called directly
1911 (F) You tried to call a subroutine in the C<CORE::> namespace
1912 with C<&foo> syntax or through a reference. Some subroutines
1913 in this package cannot yet be called that way, but must be
1914 called as barewords. Something like this will work:
1916 BEGIN { *shove = \&CORE::push; }
1917 shove @array, 1,2,3; # pushes on to @array
1919 =item CORE::%s is not a keyword
1921 (F) The CORE:: namespace is reserved for Perl keywords.
1923 =item Corrupted regexp opcode %d > %d
1925 (P) This is either an error in Perl, or, if you're using
1926 one, your L<custom regular expression engine|perlreapi>. If not the
1927 latter, report the problem through the L<perlbug> utility.
1929 =item corrupted regexp pointers
1931 (P) The regular expression engine got confused by what the regular
1932 expression compiler gave it.
1934 =item corrupted regexp program
1936 (P) The regular expression engine got passed a regexp program without a
1939 =item Corrupt malloc ptr 0x%x at 0x%x
1941 (P) The malloc package that comes with Perl had an internal failure.
1943 =item Count after length/code in unpack
1945 (F) You had an unpack template indicating a counted-length string, but
1946 you have also specified an explicit size for the string. See
1949 =item Declaring references is experimental
1951 (S experimental::declared_refs) This warning is emitted if you use
1952 a reference constructor on the right-hand side of C<my>, C<state>, C<our>, or
1953 C<local>. Simply suppress the warning if you want to use the feature, but
1954 know that in doing so you are taking the risk of using an experimental
1955 feature which may change or be removed in a future Perl version:
1957 no warnings "experimental::declared_refs";
1958 use feature "declared_refs";
1962 The following are used in lib/diagnostics.t for testing two =items that
1963 share the same description. Changes here need to be propagated to there
1965 =item Deep recursion on anonymous subroutine
1967 =item Deep recursion on subroutine "%s"
1969 (W recursion) This subroutine has called itself (directly or indirectly)
1970 100 times more than it has returned. This probably indicates an
1971 infinite recursion, unless you're writing strange benchmark programs, in
1972 which case it indicates something else.
1974 This threshold can be changed from 100, by recompiling the F<perl> binary,
1975 setting the C pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value.
1977 =item (?(DEFINE)....) does not allow branches in regex; marked by
1978 S<<-- HERE> in m/%s/
1980 (F) You used something like C<(?(DEFINE)...|..)> which is illegal. The
1981 most likely cause of this error is that you left out a parenthesis inside
1982 of the C<....> part.
1984 The S<<-- HERE> shows whereabouts in the regular expression the problem was
1987 =item %s defines neither package nor VERSION--version check failed
1989 (F) You said something like "use Module 42" but in the Module file
1990 there are neither package declarations nor a C<$VERSION>.
1992 =item delete argument is not a HASH or ARRAY element or slice
1994 (F) The argument to C<delete> must be either a hash or array element,
2000 or a hash or array slice, such as:
2002 @foo[$bar, $baz, $xyzzy]
2003 @{$ref->[12]}{"susie", "queue"}
2005 or a hash key/value or array index/value slice, such as:
2007 %foo[$bar, $baz, $xyzzy]
2008 %{$ref->[12]}{"susie", "queue"}
2010 =item Delimiter for here document is too long
2012 (F) In a here document construct like C<<<FOO>, the label C<FOO> is too
2013 long for Perl to handle. You have to be seriously twisted to write code
2014 that triggers this error.
2016 =item Deprecated use of my() in false conditional. This will be a fatal error in Perl 5.30
2018 (D deprecated) You used a declaration similar to C<my $x if 0>. There
2019 has been a long-standing bug in Perl that causes a lexical variable
2020 not to be cleared at scope exit when its declaration includes a false
2021 conditional. Some people have exploited this bug to achieve a kind of
2022 static variable. Since we intend to fix this bug, we don't want people
2023 relying on this behavior. You can achieve a similar static effect by
2024 declaring the variable in a separate block outside the function, eg
2026 sub f { my $x if 0; return $x++ }
2030 { my $x; sub f { return $x++ } }
2032 Beginning with perl 5.10.0, you can also use C<state> variables to have
2033 lexicals that are initialized only once (see L<feature>):
2035 sub f { state $x; return $x++ }
2037 This use of C<my()> in a false conditional has been deprecated since
2038 Perl 5.10, and it will become a fatal error in Perl 5.30.
2040 =item DESTROY created new reference to dead object '%s'
2042 (F) A DESTROY() method created a new reference to the object which is
2043 just being DESTROYed. Perl is confused, and prefers to abort rather
2044 than to create a dangling reference.
2046 =item Did not produce a valid header
2048 See L</500 Server error>.
2050 =item %s did not return a true value
2052 (F) A required (or used) file must return a true value to indicate that
2053 it compiled correctly and ran its initialization code correctly. It's
2054 traditional to end such a file with a "1;", though any true value would
2055 do. See L<perlfunc/require>.
2057 =item (Did you mean &%s instead?)
2059 (W misc) You probably referred to an imported subroutine &FOO as $FOO or
2062 =item (Did you mean "local" instead of "our"?)
2064 (W shadow) Remember that "our" does not localize the declared global
2065 variable. You have declared it again in the same lexical scope, which
2068 =item (Did you mean $ or @ instead of %?)
2070 (W) You probably said %hash{$key} when you meant $hash{$key} or
2071 @hash{@keys}. On the other hand, maybe you just meant %hash and got
2076 (F) You passed die() an empty string (the equivalent of C<die "">) or
2077 you called it with no args and C<$@> was empty.
2079 =item Document contains no data
2081 See L</500 Server error>.
2083 =item %s does not define %s::VERSION--version check failed
2085 (F) You said something like "use Module 42" but the Module did not
2086 define a C<$VERSION>.
2088 =item '/' does not take a repeat count
2090 (F) You cannot put a repeat count of any kind right after the '/' code.
2091 See L<perlfunc/pack>.
2093 =item do "%s" failed, '.' is no longer in @INC; did you mean do "./%s"?
2095 (D deprecated) Previously C< do "somefile"; > would search the current
2096 directory for the specified file. Since perl v5.26.0, F<.> has been
2097 removed from C<@INC> by default, so this is no longer true. To search the
2098 current directory (and only the current directory) you can write
2099 C< do "./somefile"; >.
2101 =item Don't know how to get file name
2103 (P) C<PerlIO_getname>, a perl internal I/O function specific to VMS, was
2104 somehow called on another platform. This should not happen.
2106 =item Don't know how to handle magic of type \%o
2108 (P) The internal handling of magical variables has been cursed.
2110 =item do_study: out of memory
2112 (P) This should have been caught by safemalloc() instead.
2114 =item (Do you need to predeclare %s?)
2116 (S syntax) This is an educated guess made in conjunction with the message
2117 "%s found where operator expected". It often means a subroutine or module
2118 name is being referenced that hasn't been declared yet. This may be
2119 because of ordering problems in your file, or because of a missing
2120 "sub", "package", "require", or "use" statement. If you're referencing
2121 something that isn't defined yet, you don't actually have to define the
2122 subroutine or package before the current location. You can use an empty
2123 "sub foo;" or "package FOO;" to enter a "forward" declaration.
2125 =item dump() must be written as CORE::dump() as of Perl 5.30
2127 (F) You used the obsolete C<dump()> built-in function. That was deprecated in
2128 Perl 5.8.0. As of Perl 5.30 it must be written in fully qualified format:
2131 See L<perlfunc/dump>.
2133 =item dump is not supported
2135 (F) Your machine doesn't support dump/undump.
2137 =item Duplicate free() ignored
2139 (S malloc) An internal routine called free() on something that had
2142 =item Duplicate modifier '%c' after '%c' in %s
2144 (W unpack) You have applied the same modifier more than once after a
2145 type in a pack template. See L<perlfunc/pack>.
2147 =item elseif should be elsif
2149 (S syntax) There is no keyword "elseif" in Perl because Larry thinks
2150 it's ugly. Your code will be interpreted as an attempt to call a method
2151 named "elseif" for the class returned by the following block. This is
2152 unlikely to be what you want.
2154 =item Empty \%c in regex; marked by S<<-- HERE> in m/%s/
2158 =item Empty \%c{} in regex; marked by S<<-- HERE> in m/%s/
2160 (F) You used something like C<\b{}>, C<\B{}>, C<\o{}>, C<\p>, C<\P>, or
2161 C<\x> without specifying anything for it to operate on.
2163 Unfortunately, for backwards compatibility reasons, an empty C<\x> is
2164 legal outside S<C<use re 'strict'>> and expands to a NUL character.
2166 =item Empty (?) without any modifiers in regex; marked by <-- HERE in m/%s/
2168 (W regexp) (only under C<S<use re 'strict'>>)
2169 C<(?)> does nothing, so perhaps this is a typo.
2171 =item ${^ENCODING} is no longer supported
2173 (F) The special variable C<${^ENCODING}>, formerly used to implement
2174 the C<encoding> pragma, is no longer supported as of Perl 5.26.0.
2176 Setting it to anything other than C<undef> is a fatal error as of Perl
2179 =item entering effective %s failed
2181 (F) While under the C<use filetest> pragma, switching the real and
2182 effective uids or gids failed.
2184 =item %ENV is aliased to %s
2186 (F) You're running under taint mode, and the C<%ENV> variable has been
2187 aliased to another hash, so it doesn't reflect anymore the state of the
2188 program's environment. This is potentially insecure.
2190 =item Error converting file specification %s
2192 (F) An error peculiar to VMS. Because Perl may have to deal with file
2193 specifications in either VMS or Unix syntax, it converts them to a
2194 single form when it must operate on them directly. Either you've passed
2195 an invalid file specification to Perl, or you've found a case the
2196 conversion routines don't handle. Drat.
2198 =item Eval-group in insecure regular expression
2200 (F) Perl detected tainted data when trying to compile a regular
2201 expression that contains the C<(?{ ... })> zero-width assertion, which
2202 is unsafe. See L<perlre/(?{ code })>, and L<perlsec>.
2204 =item Eval-group not allowed at runtime, use re 'eval' in regex m/%s/
2206 (F) Perl tried to compile a regular expression containing the
2207 C<(?{ ... })> zero-width assertion at run time, as it would when the
2208 pattern contains interpolated values. Since that is a security risk,
2209 it is not allowed. If you insist, you may still do this by using the
2210 C<re 'eval'> pragma or by explicitly building the pattern from an
2211 interpolated string at run time and using that in an eval(). See
2212 L<perlre/(?{ code })>.
2214 =item Eval-group not allowed, use re 'eval' in regex m/%s/
2216 (F) A regular expression contained the C<(?{ ... })> zero-width
2217 assertion, but that construct is only allowed when the C<use re 'eval'>
2218 pragma is in effect. See L<perlre/(?{ code })>.
2220 =item EVAL without pos change exceeded limit in regex; marked by
2221 S<<-- HERE> in m/%s/
2223 (F) You used a pattern that nested too many EVAL calls without consuming
2224 any text. Restructure the pattern so that text is consumed.
2226 The S<<-- HERE> shows whereabouts in the regular expression the problem was
2229 =item Excessively long <> operator
2231 (F) The contents of a <> operator may not exceed the maximum size of a
2232 Perl identifier. If you're just trying to glob a long list of
2233 filenames, try using the glob() operator, or put the filenames into a
2234 variable and glob that.
2236 =item exec? I'm not *that* kind of operating system
2238 (F) The C<exec> function is not implemented on some systems, e.g., Symbian
2239 OS. See L<perlport>.
2241 =item %sExecution of %s aborted due to compilation errors.
2243 (F) The final summary message when a Perl compilation fails.
2245 =item exists argument is not a HASH or ARRAY element or a subroutine
2247 (F) The argument to C<exists> must be a hash or array element or a
2248 subroutine with an ampersand, such as:
2254 =item exists argument is not a subroutine name
2256 (F) The argument to C<exists> for C<exists &sub> must be a subroutine name,
2257 and not a subroutine call. C<exists &sub()> will generate this error.
2259 =item Exiting eval via %s
2261 (W exiting) You are exiting an eval by unconventional means, such as a
2262 goto, or a loop control statement.
2264 =item Exiting format via %s
2266 (W exiting) You are exiting a format by unconventional means, such as a
2267 goto, or a loop control statement.
2269 =item Exiting pseudo-block via %s
2271 (W exiting) You are exiting a rather special block construct (like a
2272 sort block or subroutine) by unconventional means, such as a goto, or a
2273 loop control statement. See L<perlfunc/sort>.
2275 =item Exiting subroutine via %s
2277 (W exiting) You are exiting a subroutine by unconventional means, such
2278 as a goto, or a loop control statement.
2280 =item Exiting substitution via %s
2282 (W exiting) You are exiting a substitution by unconventional means, such
2283 as a return, a goto, or a loop control statement.
2285 =item Expecting close bracket in regex; marked by S<<-- HERE> in m/%s/
2287 (F) You wrote something like
2291 to denote a capturing group of the form
2292 L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>,
2293 but omitted the C<")">.
2295 =item Expecting close paren for nested extended charclass in regex; marked
2296 by <-- HERE in m/%s/
2298 (F) While parsing a nested extended character class like:
2300 (?[ ... (?flags:(?[ ... ])) ... ])
2303 we expected to see a close paren ')' (marked by ^) but did not.
2305 =item Expecting close paren for wrapper for nested extended charclass in
2306 regex; marked by <-- HERE in m/%s/
2308 (F) While parsing a nested extended character class like:
2310 (?[ ... (?flags:(?[ ... ])) ... ])
2313 we expected to see a close paren ')' (marked by ^) but did not.
2315 =item Expecting '(?flags:(?[...' in regex; marked by S<<-- HERE> in m/%s/
2317 (F) The C<(?[...])> extended character class regular expression construct
2318 only allows character classes (including character class escapes like
2319 C<\d>), operators, and parentheses. The one exception is C<(?flags:...)>
2320 containing at least one flag and exactly one C<(?[...])> construct.
2321 This allows a regular expression containing just C<(?[...])> to be
2322 interpolated. If you see this error message, then you probably
2323 have some other C<(?...)> construct inside your character class. See
2324 L<perlrecharclass/Extended Bracketed Character Classes>.
2326 =item Experimental aliasing via reference not enabled
2328 (F) To do aliasing via references, you must first enable the feature:
2330 no warnings "experimental::refaliasing";
2331 use feature "refaliasing";
2334 =item Experimental %s on scalar is now forbidden
2336 (F) An experimental feature added in Perl 5.14 allowed C<each>, C<keys>,
2337 C<push>, C<pop>, C<shift>, C<splice>, C<unshift>, and C<values> to be called with a
2338 scalar argument. This experiment is considered unsuccessful, and
2339 has been removed. The C<postderef> feature may meet your needs better.
2341 =item Experimental subroutine signatures not enabled
2343 (F) To use subroutine signatures, you must first enable them:
2345 no warnings "experimental::signatures";
2346 use feature "signatures";
2347 sub foo ($left, $right) { ... }
2349 =item Explicit blessing to '' (assuming package main)
2351 (W misc) You are blessing a reference to a zero length string. This has
2352 the effect of blessing the reference into the package main. This is
2353 usually not what you want. Consider providing a default target package,
2354 e.g. bless($ref, $p || 'MyPackage');
2356 =item %s: Expression syntax
2358 (A) You've accidentally run your script through B<csh> instead of Perl.
2359 Check the #! line, or manually feed your script into Perl yourself.
2361 =item %s failed--call queue aborted
2363 (F) An untrapped exception was raised while executing a UNITCHECK,
2364 CHECK, INIT, or END subroutine. Processing of the remainder of the
2365 queue of such routines has been prematurely ended.
2367 =item Failed to close in-place work file %s: %s
2369 (F) Closing an output file from in-place editing, as with the C<-i>
2370 command-line switch, failed.
2372 =item False [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
2374 (W regexp)(F) A character class range must start and end at a literal
2375 character, not another character class like C<\d> or C<[:alpha:]>. The "-"
2376 in your false range is interpreted as a literal "-". In a C<(?[...])>
2377 construct, this is an error, rather than a warning. Consider quoting
2378 the "-", "\-". The S<<-- HERE> shows whereabouts in the regular expression
2379 the problem was discovered. See L<perlre>.
2381 =item Fatal VMS error (status=%d) at %s, line %d
2383 (P) An error peculiar to VMS. Something untoward happened in a VMS
2384 system service or RTL routine; Perl's exit status should provide more
2385 details. The filename in "at %s" and the line number in "line %d" tell
2386 you which section of the Perl source code is distressed.
2388 =item fcntl is not implemented
2390 (F) Your machine apparently doesn't implement fcntl(). What is this, a
2391 PDP-11 or something?
2393 =item FETCHSIZE returned a negative value
2395 (F) A tied array claimed to have a negative number of elements, which
2398 =item Field too wide in 'u' format in pack
2400 (W pack) Each line in an uuencoded string starts with a length indicator
2401 which can't encode values above 63. So there is no point in asking for
2402 a line length bigger than that. Perl will behave as if you specified
2403 C<u63> as the format.
2405 =item File::Glob::glob() will disappear in perl 5.30. Use File::Glob::bsd_glob() instead.
2407 (D deprecated) C<< File::Glob >> has a function called C<< glob >>, which
2408 just calls C<< bsd_glob >>. However, its prototype is different from the
2409 prototype of C<< CORE::glob >>, and hence, C<< File::Glob::glob >> should
2412 C<< File::Glob::glob() >> was deprecated in perl 5.8.0. A deprecation
2413 message was issued from perl 5.26.0 onwards, and the function will
2414 disappear in perl 5.30.0.
2416 Code using C<< File::Glob::glob() >> should call
2417 C<< File::Glob::bsd_glob() >> instead.
2419 =item Filehandle %s opened only for input
2421 (W io) You tried to write on a read-only filehandle. If you intended
2422 it to be a read-write filehandle, you needed to open it with "+<" or
2423 "+>" or "+>>" instead of with "<" or nothing. If you intended only to
2424 write the file, use ">" or ">>". See L<perlfunc/open>.
2426 =item Filehandle %s opened only for output
2428 (W io) You tried to read from a filehandle opened only for writing, If
2429 you intended it to be a read/write filehandle, you needed to open it
2430 with "+<" or "+>" or "+>>" instead of with ">". If you intended only to
2431 read from the file, use "<". See L<perlfunc/open>. Another possibility
2432 is that you attempted to open filedescriptor 0 (also known as STDIN) for
2433 output (maybe you closed STDIN earlier?).
2435 =item Filehandle %s reopened as %s only for input
2437 (W io) You opened for reading a filehandle that got the same filehandle id
2438 as STDOUT or STDERR. This occurred because you closed STDOUT or STDERR
2441 =item Filehandle STDIN reopened as %s only for output
2443 (W io) You opened for writing a filehandle that got the same filehandle id
2444 as STDIN. This occurred because you closed STDIN previously.
2446 =item Final $ should be \$ or $name
2448 (F) You must now decide whether the final $ in a string was meant to be
2449 a literal dollar sign, or was meant to introduce a variable name that
2450 happens to be missing. So you have to put either the backslash or the
2453 =item flock() on closed filehandle %s
2455 (W closed) The filehandle you're attempting to flock() got itself closed
2456 some time before now. Check your control flow. flock() operates on
2457 filehandles. Are you attempting to call flock() on a dirhandle by the
2460 =item Format not terminated
2462 (F) A format must be terminated by a line with a solitary dot. Perl got
2463 to the end of your file without finding such a line.
2465 =item Format %s redefined
2467 (W redefine) You redefined a format. To suppress this warning, say
2470 no warnings 'redefine';
2471 eval "format NAME =...";
2474 =item Found = in conditional, should be ==
2484 (or something like that).
2486 =item %s found where operator expected
2488 (S syntax) The Perl lexer knows whether to expect a term or an operator.
2489 If it sees what it knows to be a term when it was expecting to see an
2490 operator, it gives you this warning. Usually it indicates that an
2491 operator or delimiter was omitted, such as a semicolon.
2493 =item gdbm store returned %d, errno %d, key "%s"
2495 (S) A warning from the GDBM_File extension that a store failed.
2497 =item gethostent not implemented
2499 (F) Your C library apparently doesn't implement gethostent(), probably
2500 because if it did, it'd feel morally obligated to return every hostname
2503 =item get%sname() on closed socket %s
2505 (W closed) You tried to get a socket or peer socket name on a closed
2506 socket. Did you forget to check the return value of your socket() call?
2508 =item getpwnam returned invalid UIC %#o for user "%s"
2510 (S) A warning peculiar to VMS. The call to C<sys$getuai> underlying the
2511 C<getpwnam> operator returned an invalid UIC.
2513 =item getsockopt() on closed socket %s
2515 (W closed) You tried to get a socket option on a closed socket. Did you
2516 forget to check the return value of your socket() call? See
2517 L<perlfunc/getsockopt>.
2519 =item given is experimental
2521 (S experimental::smartmatch) C<given> depends on smartmatch, which
2522 is experimental, so its behavior may change or even be removed
2523 in any future release of perl. See the explanation under
2524 L<perlsyn/Experimental Details on given and when>.
2526 =item Global symbol "%s" requires explicit package name (did you forget to
2529 (F) You've said "use strict" or "use strict vars", which indicates
2530 that all variables must either be lexically scoped (using "my" or "state"),
2531 declared beforehand using "our", or explicitly qualified to say
2532 which package the global variable is in (using "::").
2534 =item glob failed (%s)
2536 (S glob) Something went wrong with the external program(s) used
2537 for C<glob> and C<< <*.c> >>. Usually, this means that you supplied a C<glob>
2538 pattern that caused the external program to fail and exit with a
2539 nonzero status. If the message indicates that the abnormal exit
2540 resulted in a coredump, this may also mean that your csh (C shell)
2541 is broken. If so, you should change all of the csh-related variables
2542 in config.sh: If you have tcsh, make the variables refer to it as
2543 if it were csh (e.g. C<full_csh='/usr/bin/tcsh'>); otherwise, make them
2544 all empty (except that C<d_csh> should be C<'undef'>) so that Perl will
2545 think csh is missing. In either case, after editing config.sh, run
2546 C<./Configure -S> and rebuild Perl.
2548 =item Glob not terminated
2550 (F) The lexer saw a left angle bracket in a place where it was expecting
2551 a term, so it's looking for the corresponding right angle bracket, and
2552 not finding it. Chances are you left some needed parentheses out
2553 earlier in the line, and you really meant a "less than".
2555 =item gmtime(%f) failed
2557 (W overflow) You called C<gmtime> with a number that it could not handle:
2558 too large, too small, or NaN. The returned value is C<undef>.
2560 =item gmtime(%f) too large
2562 (W overflow) You called C<gmtime> with a number that was larger than
2563 it can reliably handle and C<gmtime> probably returned the wrong
2564 date. This warning is also triggered with NaN (the special
2565 not-a-number value).
2567 =item gmtime(%f) too small
2569 (W overflow) You called C<gmtime> with a number that was smaller than
2570 it can reliably handle and C<gmtime> probably returned the wrong date.
2572 =item Got an error from DosAllocMem
2574 (P) An error peculiar to OS/2. Most probably you're using an obsolete
2575 version of Perl, and this should not happen anyway.
2577 =item goto must have label
2579 (F) Unlike with "next" or "last", you're not allowed to goto an
2580 unspecified destination. See L<perlfunc/goto>.
2582 =item Goto undefined subroutine%s
2584 (F) You tried to call a subroutine with C<goto &sub> syntax, but
2585 the indicated subroutine hasn't been defined, or if it was, it
2586 has since been undefined.
2588 =item Group name must start with a non-digit word character in regex; marked by
2589 S<<-- HERE> in m/%s/
2591 (F) Group names must follow the rules for perl identifiers, meaning
2592 they must start with a non-digit word character. A common cause of
2593 this error is using (?&0) instead of (?0). See L<perlre>.
2595 =item ()-group starts with a count
2597 (F) A ()-group started with a count. A count is supposed to follow
2598 something: a template character or a ()-group. See L<perlfunc/pack>.
2600 =item %s had compilation errors.
2602 (F) The final summary message when a C<perl -c> fails.
2604 =item Had to create %s unexpectedly
2606 (S internal) A routine asked for a symbol from a symbol table that ought
2607 to have existed already, but for some reason it didn't, and had to be
2608 created on an emergency basis to prevent a core dump.
2610 =item %s has too many errors
2612 (F) The parser has given up trying to parse the program after 10 errors.
2613 Further error messages would likely be uninformative.
2615 =item Hexadecimal float: exponent overflow
2617 (W overflow) The hexadecimal floating point has a larger exponent
2618 than the floating point supports.
2620 =item Hexadecimal float: exponent underflow
2622 (W overflow) The hexadecimal floating point has a smaller exponent
2623 than the floating point supports. With the IEEE 754 floating point,
2624 this may also mean that the subnormals (formerly known as denormals)
2625 are being used, which may or may not be an error.
2627 =item Hexadecimal float: internal error (%s)
2629 (F) Something went horribly bad in hexadecimal float handling.
2631 =item Hexadecimal float: mantissa overflow
2633 (W overflow) The hexadecimal floating point literal had more bits in
2634 the mantissa (the part between the 0x and the exponent, also known as
2635 the fraction or the significand) than the floating point supports.
2637 =item Hexadecimal float: precision loss
2639 (W overflow) The hexadecimal floating point had internally more
2640 digits than could be output. This can be caused by unsupported
2641 long double formats, or by 64-bit integers not being available
2642 (needed to retrieve the digits under some configurations).
2644 =item Hexadecimal float: unsupported long double format
2646 (F) You have configured Perl to use long doubles but
2647 the internals of the long double format are unknown;
2648 therefore the hexadecimal float output is impossible.
2650 =item Hexadecimal number > 0xffffffff non-portable
2652 (W portable) The hexadecimal number you specified is larger than 2**32-1
2653 (4294967295) and therefore non-portable between systems. See
2654 L<perlport> for more on portability concerns.
2656 =item Identifier too long
2658 (F) Perl limits identifiers (names for variables, functions, etc.) to
2659 about 250 characters for simple names, and somewhat more for compound
2660 names (like C<$A::B>). You've exceeded Perl's limits. Future versions
2661 of Perl are likely to eliminate these arbitrary limitations.
2663 =item Ignoring zero length \N{} in character class in regex; marked by
2664 S<<-- HERE> in m/%s/
2666 (W regexp) Named Unicode character escapes (C<\N{...}>) may return a
2667 zero-length sequence. When such an escape is used in a character
2668 class its behavior is not well defined. Check that the correct
2669 escape has been used, and the correct charname handler is in scope.
2671 =item Illegal binary digit '%c'
2673 (F) You used a digit other than 0 or 1 in a binary number.
2675 =item Illegal binary digit %s ignored
2677 (W digit) You may have tried to use a digit other than 0 or 1 in a
2678 binary number. Interpretation of the binary number stopped before the
2681 =item Illegal character after '_' in prototype for %s : %s
2683 (W illegalproto) An illegal character was found in a prototype
2684 declaration. The '_' in a prototype must be followed by a ';',
2685 indicating the rest of the parameters are optional, or one of '@'
2686 or '%', since those two will accept 0 or more final parameters.
2688 =item Illegal character \%o (carriage return)
2690 (F) Perl normally treats carriage returns in the program text as
2691 it would any other whitespace, which means you should never see
2692 this error when Perl was built using standard options. For some
2693 reason, your version of Perl appears to have been built without
2694 this support. Talk to your Perl administrator.
2696 =item Illegal character following sigil in a subroutine signature
2698 (F) A parameter in a subroutine signature contained an unexpected character
2699 following the C<$>, C<@> or C<%> sigil character. Normally the sigil
2700 should be followed by the variable name or C<=> etc. Perhaps you are
2701 trying use a prototype while in the scope of C<use feature 'signatures'>?
2704 sub foo ($$) {} # legal - a prototype
2706 use feature 'signatures;
2707 sub foo ($$) {} # illegal - was expecting a signature
2709 :prototype($$) {} # legal
2712 =item Illegal character in prototype for %s : %s
2714 (W illegalproto) An illegal character was found in a prototype declaration.
2715 Legal characters in prototypes are $, @, %, *, ;, [, ], &, \, and +.
2716 Perhaps you were trying to write a subroutine signature but didn't enable
2717 that feature first (C<use feature 'signatures'>), so your signature was
2718 instead interpreted as a bad prototype.
2720 =item Illegal declaration of anonymous subroutine
2722 (F) When using the C<sub> keyword to construct an anonymous subroutine,
2723 you must always specify a block of code. See L<perlsub>.
2725 =item Illegal declaration of subroutine %s
2727 (F) A subroutine was not declared correctly. See L<perlsub>.
2729 =item Illegal division by zero
2731 (F) You tried to divide a number by 0. Either something was wrong in
2732 your logic, or you need to put a conditional in to guard against
2735 =item Illegal hexadecimal digit %s ignored
2737 (W digit) You may have tried to use a character other than 0 - 9 or
2738 A - F, a - f in a hexadecimal number. Interpretation of the hexadecimal
2739 number stopped before the illegal character.
2741 =item Illegal modulus zero
2743 (F) You tried to divide a number by 0 to get the remainder. Most
2744 numbers don't take to this kindly.
2746 =item Illegal number of bits in vec
2748 (F) The number of bits in vec() (the third argument) must be a power of
2749 two from 1 to 32 (or 64, if your platform supports that).
2751 =item Illegal octal digit '%c'
2753 (F) You used an 8 or 9 in an octal number.
2755 =item Illegal octal digit %s ignored
2757 (W digit) You may have tried to use an 8 or 9 in an octal number.
2758 Interpretation of the octal number stopped before the 8 or 9.
2760 =item Illegal operator following parameter in a subroutine signature
2762 (F) A parameter in a subroutine signature, was followed by something
2763 other than C<=> introducing a default, C<,> or C<)>.
2765 use feature 'signatures';
2766 sub foo ($=1) {} # legal
2767 sub foo ($a = 1) {} # legal
2768 sub foo ($a += 1) {} # illegal
2769 sub foo ($a == 1) {} # illegal
2771 =item Illegal pattern in regex; marked by S<<-- HERE> in m/%s/
2773 (F) You wrote something like
2777 The C<"+"> is valid only when followed by digits, indicating a
2778 capturing group. See
2779 L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>.
2781 =item Illegal suidscript
2783 (F) The script run under suidperl was somehow illegal.
2785 =item Illegal switch in PERL5OPT: -%c
2787 (X) The PERL5OPT environment variable may only be used to set the
2788 following switches: B<-[CDIMUdmtw]>.
2790 =item Illegal user-defined property name
2792 (F) You specified a Unicode-like property name in a regular expression
2793 pattern (using C<\p{}> or C<\P{}>) that Perl knows isn't an official
2794 Unicode property, and was likely meant to be a user-defined property
2795 name, but it can't be one of those, as they must begin with either C<In>
2796 or C<Is>. Check the spelling. See also
2797 L</Can't find Unicode property definition "%s">.
2799 =item Ill-formed CRTL environ value "%s"
2801 (W internal) A warning peculiar to VMS. Perl tried to read the CRTL's
2802 internal environ array, and encountered an element without the C<=>
2803 delimiter used to separate keys from values. The element is ignored.
2805 =item Ill-formed message in prime_env_iter: |%s|
2807 (W internal) A warning peculiar to VMS. Perl tried to read a logical
2808 name or CLI symbol definition when preparing to iterate over %ENV, and
2809 didn't see the expected delimiter between key and value, so the line was
2812 =item (in cleanup) %s
2814 (W misc) This prefix usually indicates that a DESTROY() method raised
2815 the indicated exception. Since destructors are usually called by the
2816 system at arbitrary points during execution, and often a vast number of
2817 times, the warning is issued only once for any number of failures that
2818 would otherwise result in the same message being repeated.
2820 Failure of user callbacks dispatched using the C<G_KEEPERR> flag could
2821 also result in this warning. See L<perlcall/G_KEEPERR>.
2823 =item Incomplete expression within '(?[ ])' in regex; marked by S<<-- HERE>
2826 (F) There was a syntax error within the C<(?[ ])>. This can happen if the
2827 expression inside the construct was completely empty, or if there are
2828 too many or few operands for the number of operators. Perl is not smart
2829 enough to give you a more precise indication as to what is wrong.
2831 =item Inconsistent hierarchy during C3 merge of class '%s': merging failed on
2834 (F) The method resolution order (MRO) of the given class is not
2835 C3-consistent, and you have enabled the C3 MRO for this class. See the C3
2836 documentation in L<mro> for more information.
2838 =item Indentation on line %d of here-doc doesn't match delimiter
2840 (F) You have an indented here-document where one or more of its lines
2841 have whitespace at the beginning that does not match the closing
2844 For example, line 2 below is wrong because it does not have at least
2845 2 spaces, but lines 1 and 3 are fine because they have at least 2:
2855 Note that tabs and spaces are compared strictly, meaning 1 tab will
2858 =item Infinite recursion in regex
2860 (F) You used a pattern that references itself without consuming any input
2861 text. You should check the pattern to ensure that recursive patterns
2862 either consume text or fail.
2864 =item Infinite recursion via empty pattern
2866 (F) You tried to use the empty pattern inside of a regex code block,
2867 for instance C</(?{ s!!! })/>, which resulted in re-executing
2868 the same pattern, which is an infinite loop which is broken by
2869 throwing an exception.
2871 =item Initialization of state variables in list currently forbidden
2873 (F) C<state> only permits initializing a single variable, specified
2874 without parentheses. So C<state $a = 42> and C<state @a = qw(a b c)> are
2875 allowed, but not C<state ($a) = 42> or C<(state $a) = 42>. To initialize
2876 more than one C<state> variable, initialize them one at a time.
2878 =item %%s[%s] in scalar context better written as $%s[%s]
2880 (W syntax) In scalar context, you've used an array index/value slice
2881 (indicated by %) to select a single element of an array. Generally
2882 it's better to ask for a scalar value (indicated by $). The difference
2883 is that C<$foo[&bar]> always behaves like a scalar, both in the value it
2884 returns and when evaluating its argument, while C<%foo[&bar]> provides
2885 a list context to its subscript, which can do weird things if you're
2886 expecting only one subscript. When called in list context, it also
2887 returns the index (what C<&bar> returns) in addition to the value.
2889 =item %%s{%s} in scalar context better written as $%s{%s}
2891 (W syntax) In scalar context, you've used a hash key/value slice
2892 (indicated by %) to select a single element of a hash. Generally it's
2893 better to ask for a scalar value (indicated by $). The difference
2894 is that C<$foo{&bar}> always behaves like a scalar, both in the value
2895 it returns and when evaluating its argument, while C<@foo{&bar}> and
2896 provides a list context to its subscript, which can do weird things
2897 if you're expecting only one subscript. When called in list context,
2898 it also returns the key in addition to the value.
2900 =item Insecure dependency in %s
2902 (F) You tried to do something that the tainting mechanism didn't like.
2903 The tainting mechanism is turned on when you're running setuid or
2904 setgid, or when you specify B<-T> to turn it on explicitly. The
2905 tainting mechanism labels all data that's derived directly or indirectly
2906 from the user, who is considered to be unworthy of your trust. If any
2907 such data is used in a "dangerous" operation, you get this error. See
2908 L<perlsec> for more information.
2910 =item Insecure directory in %s
2912 (F) You can't use system(), exec(), or a piped open in a setuid or
2913 setgid script if C<$ENV{PATH}> contains a directory that is writable by
2914 the world. Also, the PATH must not contain any relative directory.
2917 =item Insecure $ENV{%s} while running %s
2919 (F) You can't use system(), exec(), or a piped open in a setuid or
2920 setgid script if any of C<$ENV{PATH}>, C<$ENV{IFS}>, C<$ENV{CDPATH}>,
2921 C<$ENV{ENV}>, C<$ENV{BASH_ENV}> or C<$ENV{TERM}> are derived from data
2922 supplied (or potentially supplied) by the user. The script must set
2923 the path to a known value, using trustworthy data. See L<perlsec>.
2925 =item Insecure user-defined property %s
2927 (F) Perl detected tainted data when trying to compile a regular
2928 expression that contains a call to a user-defined character property
2929 function, i.e. C<\p{IsFoo}> or C<\p{InFoo}>.
2930 See L<perlunicode/User-Defined Character Properties> and L<perlsec>.
2932 =item Integer overflow in format string for %s
2934 (F) The indexes and widths specified in the format string of C<printf()>
2935 or C<sprintf()> are too large. The numbers must not overflow the size of
2936 integers for your architecture.
2938 =item Integer overflow in %s number
2940 (S overflow) The hexadecimal, octal or binary number you have specified
2941 either as a literal or as an argument to hex() or oct() is too big for
2942 your architecture, and has been converted to a floating point number.
2943 On a 32-bit architecture the largest hexadecimal, octal or binary number
2944 representable without overflow is 0xFFFFFFFF, 037777777777, or
2945 0b11111111111111111111111111111111 respectively. Note that Perl
2946 transparently promotes all numbers to a floating point representation
2947 internally--subject to loss of precision errors in subsequent
2950 =item Integer overflow in srand
2952 (S overflow) The number you have passed to srand is too big to fit
2953 in your architecture's integer representation. The number has been
2954 replaced with the largest integer supported (0xFFFFFFFF on 32-bit
2955 architectures). This means you may be getting less randomness than
2956 you expect, because different random seeds above the maximum will
2957 return the same sequence of random numbers.
2959 =item Integer overflow in version
2961 =item Integer overflow in version %d
2963 (W overflow) Some portion of a version initialization is too large for
2964 the size of integers for your architecture. This is not a warning
2965 because there is no rational reason for a version to try and use an
2966 element larger than typically 2**32. This is usually caused by trying
2967 to use some odd mathematical operation as a version, like 100/9.
2969 =item Internal disaster in regex; marked by S<<-- HERE> in m/%s/
2971 (P) Something went badly wrong in the regular expression parser.
2972 The S<<-- HERE> shows whereabouts in the regular expression the problem was
2975 =item Internal inconsistency in tracking vforks
2977 (S) A warning peculiar to VMS. Perl keeps track of the number of times
2978 you've called C<fork> and C<exec>, to determine whether the current call
2979 to C<exec> should affect the current script or a subprocess (see
2980 L<perlvms/"exec LIST">). Somehow, this count has become scrambled, so
2981 Perl is making a guess and treating this C<exec> as a request to
2982 terminate the Perl script and execute the specified command.
2984 =item internal %<num>p might conflict with future printf extensions
2986 (S internal) Perl's internal routine that handles C<printf> and C<sprintf>
2987 formatting follows a slightly different set of rules when called from
2988 C or XS code. Specifically, formats consisting of digits followed
2989 by "p" (e.g., "%7p") are reserved for future use. If you see this
2990 message, then an XS module tried to call that routine with one such
2993 =item Internal urp in regex; marked by S<<-- HERE> in m/%s/
2995 (P) Something went badly awry in the regular expression parser. The
2996 S<<-- HERE> shows whereabouts in the regular expression the problem was
2999 =item %s (...) interpreted as function
3001 (W syntax) You've run afoul of the rule that says that any list operator
3002 followed by parentheses turns into a function, with all the list
3003 operators arguments found inside the parentheses. See
3004 L<perlop/Terms and List Operators (Leftward)>.
3006 =item In '(?...)', the '(' and '?' must be adjacent in regex;
3007 marked by S<<-- HERE> in m/%s/
3009 (F) The two-character sequence C<"(?"> in this context in a regular
3010 expression pattern should be an indivisible token, with nothing
3011 intervening between the C<"("> and the C<"?">, but you separated them
3014 =item In '(*...)', the '(' and '*' must be adjacent in regex;
3015 marked by S<<-- HERE> in m/%s/
3017 (F) The two-character sequence C<"(*"> in this context in a regular
3018 expression pattern should be an indivisible token, with nothing
3019 intervening between the C<"("> and the C<"*">, but you separated them.
3020 Fix the pattern and retry.
3022 =item Invalid %s attribute: %s
3024 (F) The indicated attribute for a subroutine or variable was not recognized
3025 by Perl or by a user-supplied handler. See L<attributes>.
3027 =item Invalid %s attributes: %s
3029 (F) The indicated attributes for a subroutine or variable were not
3030 recognized by Perl or by a user-supplied handler. See L<attributes>.
3032 =item Invalid character in charnames alias definition; marked by
3035 (F) You tried to create a custom alias for a character name, with
3036 the C<:alias> option to C<use charnames> and the specified character in
3037 the indicated name isn't valid. See L<charnames/CUSTOM ALIASES>.
3039 =item Invalid \0 character in %s for %s: %s\0%s
3041 (W syscalls) Embedded \0 characters in pathnames or other system call
3042 arguments produce a warning as of 5.20. The parts after the \0 were
3043 formerly ignored by system calls.
3045 =item Invalid character in \N{...}; marked by S<<-- HERE> in \N{%s}
3047 (F) Only certain characters are valid for character names. The
3048 indicated one isn't. See L<charnames/CUSTOM ALIASES>.
3050 =item Invalid conversion in %s: "%s"
3052 (W printf) Perl does not understand the given format conversion. See
3053 L<perlfunc/sprintf>.
3055 =item Invalid escape in the specified encoding in regex; marked by
3056 S<<-- HERE> in m/%s/
3058 (W regexp)(F) The numeric escape (for example C<\xHH>) of value < 256
3059 didn't correspond to a single character through the conversion
3060 from the encoding specified by the encoding pragma.
3061 The escape was replaced with REPLACEMENT CHARACTER (U+FFFD)
3062 instead, except within S<C<(?[ ])>>, where it is a fatal error.
3063 The S<<-- HERE> shows whereabouts in the regular expression the
3064 escape was discovered.
3066 =item Invalid hexadecimal number in \N{U+...}
3068 =item Invalid hexadecimal number in \N{U+...} in regex; marked by
3069 S<<-- HERE> in m/%s/
3071 (F) The character constant represented by C<...> is not a valid hexadecimal
3072 number. Either it is empty, or you tried to use a character other than
3073 0 - 9 or A - F, a - f in a hexadecimal number.
3075 =item Invalid module name %s with -%c option: contains single ':'
3077 (F) The module argument to perl's B<-m> and B<-M> command-line options
3078 cannot contain single colons in the module name, but only in the
3079 arguments after "=". In other words, B<-MFoo::Bar=:baz> is ok, but
3080 B<-MFoo:Bar=baz> is not.
3082 =item Invalid mro name: '%s'
3084 (F) You tried to C<mro::set_mro("classname", "foo")> or C<use mro 'foo'>,
3085 where C<foo> is not a valid method resolution order (MRO). Currently,
3086 the only valid ones supported are C<dfs> and C<c3>, unless you have loaded
3087 a module that is a MRO plugin. See L<mro> and L<perlmroapi>.
3089 =item Invalid negative number (%s) in chr
3091 (W utf8) You passed a negative number to C<chr>. Negative numbers are
3092 not valid character numbers, so it returns the Unicode replacement
3095 =item Invalid number '%s' for -C option.
3097 (F) You supplied a number to the -C option that either has extra leading
3098 zeroes or overflows perl's unsigned integer representation.
3100 =item invalid option -D%c, use -D'' to see choices
3102 (S debugging) Perl was called with invalid debugger flags. Call perl
3103 with the B<-D> option with no flags to see the list of acceptable values.
3104 See also L<perlrun/-Dletters>.
3106 =item Invalid quantifier in {,} in regex; marked by S<<-- HERE> in m/%s/
3108 (F) The pattern looks like a {min,max} quantifier, but the min or max
3109 could not be parsed as a valid number - either it has leading zeroes,
3110 or it represents too big a number to cope with. The S<<-- HERE> shows
3111 where in the regular expression the problem was discovered. See L<perlre>.
3113 =item Invalid [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
3115 (F) The range specified in a character class had a minimum character
3116 greater than the maximum character. One possibility is that you forgot the
3117 C<{}> from your ending C<\x{}> - C<\x> without the curly braces can go only
3118 up to C<ff>. The S<<-- HERE> shows whereabouts in the regular expression the
3119 problem was discovered. See L<perlre>.
3121 =item Invalid range "%s" in transliteration operator
3123 (F) The range specified in the tr/// or y/// operator had a minimum
3124 character greater than the maximum character. See L<perlop>.
3126 =item Invalid separator character %s in attribute list
3128 (F) Something other than a colon or whitespace was seen between the
3129 elements of an attribute list. If the previous attribute had a
3130 parenthesised parameter list, perhaps that list was terminated too soon.
3133 =item Invalid separator character %s in PerlIO layer specification %s
3135 (W layer) When pushing layers onto the Perl I/O system, something other
3136 than a colon or whitespace was seen between the elements of a layer list.
3137 If the previous attribute had a parenthesised parameter list, perhaps that
3138 list was terminated too soon.
3140 =item Invalid strict version format (%s)
3142 (F) A version number did not meet the "strict" criteria for versions.
3143 A "strict" version number is a positive decimal number (integer or
3144 decimal-fraction) without exponentiation or else a dotted-decimal
3145 v-string with a leading 'v' character and at least three components.
3146 The parenthesized text indicates which criteria were not met.
3147 See the L<version> module for more details on allowed version formats.
3149 =item Invalid type '%s' in %s
3151 (F) The given character is not a valid pack or unpack type.
3152 See L<perlfunc/pack>.
3154 (W) The given character is not a valid pack or unpack type but used to be
3157 =item Invalid version format (%s)
3159 (F) A version number did not meet the "lax" criteria for versions.
3160 A "lax" version number is a positive decimal number (integer or
3161 decimal-fraction) without exponentiation or else a dotted-decimal
3162 v-string. If the v-string has fewer than three components, it
3163 must have a leading 'v' character. Otherwise, the leading 'v' is
3164 optional. Both decimal and dotted-decimal versions may have a
3165 trailing "alpha" component separated by an underscore character
3166 after a fractional or dotted-decimal component. The parenthesized
3167 text indicates which criteria were not met. See the L<version> module
3168 for more details on allowed version formats.
3170 =item Invalid version object
3172 (F) The internal structure of the version object was invalid.
3173 Perhaps the internals were modified directly in some way or
3174 an arbitrary reference was blessed into the "version" class.
3176 =item In '(*VERB...)', the '(' and '*' must be adjacent in regex;
3177 marked by S<<-- HERE> in m/%s/
3179 (F) The two-character sequence C<"(*"> in this context in a regular
3180 expression pattern should be an indivisible token, with nothing
3181 intervening between the C<"("> and the C<"*">, but you separated them.
3183 =item ioctl is not implemented
3185 (F) Your machine apparently doesn't implement ioctl(), which is pretty
3186 strange for a machine that supports C.
3188 =item ioctl() on unopened %s
3190 (W unopened) You tried ioctl() on a filehandle that was never opened.
3191 Check your control flow and number of arguments.
3193 =item IO layers (like '%s') unavailable
3195 (F) Your Perl has not been configured to have PerlIO, and therefore
3196 you cannot use IO layers. To have PerlIO, Perl must be configured
3199 =item IO::Socket::atmark not implemented on this architecture
3201 (F) Your machine doesn't implement the sockatmark() functionality,
3202 neither as a system call nor an ioctl call (SIOCATMARK).
3204 =item '%s' is an unknown bound type in regex; marked by S<<-- HERE> in m/%s/
3206 (F) You used C<\b{...}> or C<\B{...}> and the C<...> is not known to
3207 Perl. The current valid ones are given in
3208 L<perlrebackslash/\b{}, \b, \B{}, \B>.
3210 =item %s() isn't allowed on :utf8 handles
3212 (F) The sysread(), recv(), syswrite() and send() operators are
3213 not allowed on handles that have the C<:utf8> layer, either explicitly, or
3214 implicitly, eg., with the C<:encoding(UTF-16LE)> layer.
3216 Previously sysread() and recv() currently use only the C<:utf8> flag for the stream,
3217 ignoring the actual layers. Since sysread() and recv() did no UTF-8
3218 validation they can end up creating invalidly encoded scalars.
3220 Similarly, syswrite() and send() used only the C<:utf8> flag, otherwise ignoring
3221 any layers. If the flag is set, both wrote the value UTF-8 encoded, even if
3222 the layer is some different encoding, such as the example above.
3224 Ideally, all of these operators would completely ignore the C<:utf8> state,
3225 working only with bytes, but this would result in silently breaking existing
3228 =item "%s" is more clearly written simply as "%s" in regex; marked by S<<-- HERE> in m/%s/
3230 (W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
3232 You specified a character that has the given plainer way of writing it, and
3233 which is also portable to platforms running with different character sets.
3235 =item $* is no longer supported as of Perl 5.30
3237 (F) The special variable C<$*>, deprecated in older perls, was removed in
3238 5.10.0, is no longer supported and is a fatal error as of Perl 5.30. In
3239 previous versions of perl the use of C<$*> enabled or disabled multi-line
3240 matching within a string.
3242 Instead of using C<$*> you should use the C</m> (and maybe C</s>) regexp
3243 modifiers. You can enable C</m> for a lexical scope (even a whole file)
3244 with C<use re '/m'>. (In older versions: when C<$*> was set to a true value
3245 then all regular expressions behaved as if they were written using C</m>.)
3247 Use of this variable will be a fatal error in Perl 5.30.
3249 =item $# is no longer supported as of Perl 5.30
3251 (F) The special variable C<$#>, deprecated in older perls, was removed as of
3252 5.10.0, is no longer supported and is a fatal error as of Perl 5.30. You
3253 should use the printf/sprintf functions instead.
3255 =item '%s' is not a code reference
3257 (W overload) The second (fourth, sixth, ...) argument of
3258 overload::constant needs to be a code reference. Either
3259 an anonymous subroutine, or a reference to a subroutine.
3261 =item '%s' is not an overloadable type
3263 (W overload) You tried to overload a constant type the overload package is
3266 =item -i used with no filenames on the command line, reading from STDIN
3268 (S inplace) The C<-i> option was passed on the command line, indicating
3269 that the script is intended to edit files in place, but no files were
3270 given. This is usually a mistake, since editing STDIN in place doesn't
3271 make sense, and can be confusing because it can make perl look like
3272 it is hanging when it is really just trying to read from STDIN. You
3273 should either pass a filename to edit, or remove C<-i> from the command
3274 line. See L<perlrun> for more details.
3276 =item Junk on end of regexp in regex m/%s/
3278 (P) The regular expression parser is confused.
3280 =item Label not found for "last %s"
3282 (F) You named a loop to break out of, but you're not currently in a loop
3283 of that name, not even if you count where you were called from. See
3286 =item Label not found for "next %s"
3288 (F) You named a loop to continue, but you're not currently in a loop of
3289 that name, not even if you count where you were called from. See
3292 =item Label not found for "redo %s"
3294 (F) You named a loop to restart, but you're not currently in a loop of
3295 that name, not even if you count where you were called from. See
3298 =item leaving effective %s failed
3300 (F) While under the C<use filetest> pragma, switching the real and
3301 effective uids or gids failed.
3303 =item length/code after end of string in unpack
3305 (F) While unpacking, the string buffer was already used up when an unpack
3306 length/code combination tried to obtain more data. This results in
3307 an undefined value for the length. See L<perlfunc/pack>.
3309 =item length() used on %s (did you mean "scalar(%s)"?)
3311 (W syntax) You used length() on either an array or a hash when you
3312 probably wanted a count of the items.
3314 Array size can be obtained by doing:
3318 The number of items in a hash can be obtained by doing:
3322 =item Lexing code attempted to stuff non-Latin-1 character into Latin-1 input
3324 (F) An extension is attempting to insert text into the current parse
3325 (using L<lex_stuff_pvn|perlapi/lex_stuff_pvn> or similar), but tried to insert a character that
3326 couldn't be part of the current input. This is an inherent pitfall
3327 of the stuffing mechanism, and one of the reasons to avoid it. Where
3328 it is necessary to stuff, stuffing only plain ASCII is recommended.
3330 =item Lexing code internal error (%s)
3332 (F) Lexing code supplied by an extension violated the lexer's API in a
3335 =item listen() on closed socket %s
3337 (W closed) You tried to do a listen on a closed socket. Did you forget
3338 to check the return value of your socket() call? See
3341 =item List form of piped open not implemented
3343 (F) On some platforms, notably Windows, the three-or-more-arguments
3344 form of C<open> does not support pipes, such as C<open($pipe, '|-', @args)>.
3345 Use the two-argument C<open($pipe, '|prog arg1 arg2...')> form instead.
3347 =item Literal vertical space in [] is illegal except under /x in regex;
3348 marked by S<<-- HERE> in m/%s/
3350 (F) (only under C<S<use re 'strict'>> or within C<(?[...])>)
3352 Likely you forgot the C</x> modifier or there was a typo in the pattern.
3353 For example, did you really mean to match a form-feed? If so, all the
3354 ASCII vertical space control characters are representable by escape
3355 sequences which won't present such a jarring appearance as your pattern
3356 does when displayed.
3363 =item %s: loadable library and perl binaries are mismatched (got handshake key %p, needed %p)
3365 (P) A dynamic loading library C<.so> or C<.dll> was being loaded into the
3366 process that was built against a different build of perl than the
3367 said library was compiled against. Reinstalling the XS module will
3368 likely fix this error.
3370 =item Locale '%s' contains (at least) the following characters which
3371 have unexpected meanings: %s The Perl program will use the expected
3374 (W locale) You are using the named UTF-8 locale. UTF-8 locales are
3375 expected to have very particular behavior, which most do. This message
3376 arises when perl found some departures from the expectations, and is
3377 notifying you that the expected behavior overrides these differences.
3378 In some cases the differences are caused by the locale definition being
3379 defective, but the most common causes of this warning are when there are
3380 ambiguities and conflicts in following the Standard, and the locale has
3381 chosen an approach that differs from Perl's.
3383 One of these is because that, contrary to the claims, Unicode is not
3384 completely locale insensitive. Turkish and some related languages
3385 have two types of C<"I"> characters. One is dotted in both upper- and
3386 lowercase, and the other is dotless in both cases. Unicode allows a
3387 locale to use either the Turkish rules, or the rules used in all other
3388 instances, where there is only one type of C<"I">, which is dotless in
3389 the uppercase, and dotted in the lower. The perl core does not (yet)
3390 handle the Turkish case, and this message warns you of that. Instead,
3391 the L<Unicode::Casing> module allows you to mostly implement the Turkish
3394 The other common cause is for the characters
3398 These are probematic. The C standard says that these should be
3399 considered punctuation in the C locale (and the POSIX standard defers to
3400 the C standard), and Unicode is generally considered a superset of
3401 the C locale. But Unicode has added an extra category, "Symbol", and
3402 classifies these particular characters as being symbols. Most UTF-8
3403 locales have them treated as punctuation, so that L<ispunct(2)> returns
3404 non-zero for them. But a few locales have it return 0. Perl takes
3405 the first approach, not using C<ispunct()> at all (see L<Note [5] in
3406 perlrecharclass|perlrecharclass/[5]>), and this message is raised to notify you that you
3407 are getting Perl's approach, not the locale's.
3409 =item Locale '%s' may not work well.%s
3411 (W locale) You are using the named locale, which is a non-UTF-8 one, and
3412 which perl has determined is not fully compatible with what it can
3413 handle. The second C<%s> gives a reason.
3415 By far the most common reason is that the locale has characters in it
3416 that are represented by more than one byte. The only such locales that
3417 Perl can handle are the UTF-8 locales. Most likely the specified locale
3418 is a non-UTF-8 one for an East Asian language such as Chinese or
3419 Japanese. If the locale is a superset of ASCII, the ASCII portion of it
3422 Some essentially obsolete locales that aren't supersets of ASCII, mainly
3423 those in ISO 646 or other 7-bit locales, such as ASMO 449, can also have
3424 problems, depending on what portions of the ASCII character set get
3425 changed by the locale and are also used by the program.
3426 The warning message lists the determinable conflicting characters.
3428 Note that not all incompatibilities are found.
3430 If this happens to you, there's not much you can do except switch to use a
3431 different locale or use L<Encode> to translate from the locale into
3432 UTF-8; if that's impracticable, you have been warned that some things
3435 This message is output once each time a bad locale is switched into
3436 within the scope of C<S<use locale>>, or on the first possibly-affected
3437 operation if the C<S<use locale>> inherits a bad one. It is not raised
3438 for any operations from the L<POSIX> module.
3440 =item localtime(%f) failed
3442 (W overflow) You called C<localtime> with a number that it could not handle:
3443 too large, too small, or NaN. The returned value is C<undef>.
3445 =item localtime(%f) too large
3447 (W overflow) You called C<localtime> with a number that was larger
3448 than it can reliably handle and C<localtime> probably returned the
3449 wrong date. This warning is also triggered with NaN (the special
3450 not-a-number value).
3452 =item localtime(%f) too small
3454 (W overflow) You called C<localtime> with a number that was smaller
3455 than it can reliably handle and C<localtime> probably returned the
3458 =item Lookbehind longer than %d not implemented in regex m/%s/
3460 (F) There is currently a limit on the length of string which lookbehind can
3461 handle. This restriction may be eased in a future release.
3463 =item Lost precision when %s %f by 1
3465 (W imprecision) The value you attempted to increment or decrement by one
3466 is too large for the underlying floating point representation to store
3467 accurately, hence the target of C<++> or C<--> is unchanged. Perl issues this
3468 warning because it has already switched from integers to floating point
3469 when values are too large for integers, and now even floating point is
3470 insufficient. You may wish to switch to using L<Math::BigInt> explicitly.
3472 =item lstat() on filehandle%s
3474 (W io) You tried to do an lstat on a filehandle. What did you mean
3475 by that? lstat() makes sense only on filenames. (Perl did a fstat()
3476 instead on the filehandle.)
3478 =item lvalue attribute %s already-defined subroutine
3480 (W misc) Although L<attributes.pm|attributes> allows this, turning the lvalue
3481 attribute on or off on a Perl subroutine that is already defined
3482 does not always work properly. It may or may not do what you
3483 want, depending on what code is inside the subroutine, with exact
3484 details subject to change between Perl versions. Only do this
3485 if you really know what you are doing.
3487 =item lvalue attribute ignored after the subroutine has been defined
3489 (W misc) Using the C<:lvalue> declarative syntax to make a Perl
3490 subroutine an lvalue subroutine after it has been defined is
3491 not permitted. To make the subroutine an lvalue subroutine,
3492 add the lvalue attribute to the definition, or put the C<sub
3493 foo :lvalue;> declaration before the definition.
3495 See also L<attributes.pm|attributes>.
3497 =item Magical list constants are not supported
3499 (F) You assigned a magical array to a stash element, and then tried
3500 to use the subroutine from the same slot. You are asking Perl to do
3501 something it cannot do, details subject to change between Perl versions.
3503 =item Malformed integer in [] in pack
3505 (F) Between the brackets enclosing a numeric repeat count only digits
3506 are permitted. See L<perlfunc/pack>.
3508 =item Malformed integer in [] in unpack
3510 (F) Between the brackets enclosing a numeric repeat count only digits
3511 are permitted. See L<perlfunc/pack>.
3513 =item Malformed PERLLIB_PREFIX
3515 (F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form
3522 with nonempty prefix1 and prefix2. If C<prefix1> is indeed a prefix of
3523 a builtin library search path, prefix2 is substituted. The error may
3524 appear if components are not found, or are too long. See
3525 "PERLLIB_PREFIX" in L<perlos2>.
3527 =item Malformed prototype for %s: %s
3529 (F) You tried to use a function with a malformed prototype. The
3530 syntax of function prototypes is given a brief compile-time check for
3531 obvious errors like invalid characters. A more rigorous check is run
3532 when the function is called.
3533 Perhaps the function's author was trying to write a subroutine signature
3534 but didn't enable that feature first (C<use feature 'signatures'>),
3535 so the signature was instead interpreted as a bad prototype.
3537 =item Malformed UTF-8 character%s
3539 (S utf8)(F) Perl detected a string that should be UTF-8, but didn't
3540 comply with UTF-8 encoding rules, or represents a code point whose
3541 ordinal integer value doesn't fit into the word size of the current
3542 platform (overflows). Details as to the exact malformation are given in
3543 the variable, C<%s>, part of the message.
3545 One possible cause is that you set the UTF8 flag yourself for data that
3546 you thought to be in UTF-8 but it wasn't (it was for example legacy 8-bit
3547 data). To guard against this, you can use C<Encode::decode('UTF-8', ...)>.
3549 If you use the C<:encoding(UTF-8)> PerlIO layer for input, invalid byte
3550 sequences are handled gracefully, but if you use C<:utf8>, the flag is set
3551 without validating the data, possibly resulting in this error message.
3553 See also L<Encode/"Handling Malformed Data">.
3555 =item Malformed UTF-8 returned by \N{%s} immediately after '%s'
3557 (F) The charnames handler returned malformed UTF-8.
3559 =item Malformed UTF-8 string in "%s"
3561 (F) This message indicates a bug either in the Perl core or in XS
3562 code. Such code was trying to find out if a character, allegedly
3563 stored internally encoded as UTF-8, was of a given type, such as
3564 being punctuation or a digit. But the character was not encoded
3565 in legal UTF-8. The C<%s> is replaced by a string that can be used
3566 by knowledgeable people to determine what the type being checked
3569 Passing malformed strings was deprecated in Perl 5.18, and
3570 became fatal in Perl 5.26.
3572 =item Malformed UTF-8 string in '%c' format in unpack
3574 (F) You tried to unpack something that didn't comply with UTF-8 encoding
3575 rules and perl was unable to guess how to make more progress.
3577 =item Malformed UTF-8 string in pack
3579 (F) You tried to pack something that didn't comply with UTF-8 encoding
3580 rules and perl was unable to guess how to make more progress.
3582 =item Malformed UTF-8 string in unpack
3584 (F) You tried to unpack something that didn't comply with UTF-8 encoding
3585 rules and perl was unable to guess how to make more progress.
3587 =item Malformed UTF-16 surrogate
3589 (F) Perl thought it was reading UTF-16 encoded character data but while
3590 doing it Perl met a malformed Unicode surrogate.
3592 =item Mandatory parameter follows optional parameter
3594 (F) In a subroutine signature, you wrote something like "$a = undef,
3595 $b", making an earlier parameter optional and a later one mandatory.
3596 Parameters are filled from left to right, so it's impossible for the
3597 caller to omit an earlier one and pass a later one. If you want to act
3598 as if the parameters are filled from right to left, declare the rightmost
3599 optional and then shuffle the parameters around in the subroutine's body.
3601 =item Matched non-Unicode code point 0x%X against Unicode property; may
3604 (S non_unicode) Perl allows strings to contain a superset of
3605 Unicode code points; each code point may be as large as what is storable
3606 in a signed integer on your system, but these may not be accepted by
3607 other languages/systems. This message occurs when you matched a string
3608 containing such a code point against a regular expression pattern, and
3609 the code point was matched against a Unicode property, C<\p{...}> or
3610 C<\P{...}>. Unicode properties are only defined on Unicode code points,
3611 so the result of this match is undefined by Unicode, but Perl (starting
3612 in v5.20) treats non-Unicode code points as if they were typical
3613 unassigned Unicode ones, and matched this one accordingly. Whether a
3614 given property matches these code points or not is specified in
3615 L<perluniprops/Properties accessible through \p{} and \P{}>.
3617 This message is suppressed (unless it has been made fatal) if it is
3618 immaterial to the results of the match if the code point is Unicode or
3619 not. For example, the property C<\p{ASCII_Hex_Digit}> only can match
3620 the 22 characters C<[0-9A-Fa-f]>, so obviously all other code points,
3621 Unicode or not, won't match it. (And C<\P{ASCII_Hex_Digit}> will match
3622 every code point except these 22.)
3624 Getting this message indicates that the outcome of the match arguably
3625 should have been the opposite of what actually happened. If you think
3626 that is the case, you may wish to make the C<non_unicode> warnings
3627 category fatal; if you agree with Perl's decision, you may wish to turn
3630 See L<perlunicode/Beyond Unicode code points> for more information.
3632 =item %s matches null string many times in regex; marked by S<<-- HERE> in
3635 (W regexp) The pattern you've specified would be an infinite loop if the
3636 regular expression engine didn't specifically check for that. The S<<-- HERE>
3637 shows whereabouts in the regular expression the problem was discovered.
3640 =item Maximal count of pending signals (%u) exceeded
3642 (F) Perl aborted due to too high a number of signals pending. This
3643 usually indicates that your operating system tried to deliver signals
3644 too fast (with a very high priority), starving the perl process from
3645 resources it would need to reach a point where it can process signals
3646 safely. (See L<perlipc/"Deferred Signals (Safe Signals)">.)
3648 =item "%s" may clash with future reserved word
3650 (W) This warning may be due to running a perl5 script through a perl4
3651 interpreter, especially if the word that is being warned about is
3654 =item '%' may not be used in pack
3656 (F) You can't pack a string by supplying a checksum, because the
3657 checksumming process loses information, and you can't go the other way.
3658 See L<perlfunc/unpack>.
3660 =item Method for operation %s not found in package %s during blessing
3662 (F) An attempt was made to specify an entry in an overloading table that
3663 doesn't resolve to a valid subroutine. See L<overload>.
3665 =item Method %s not permitted
3667 See L</500 Server error>.
3669 =item Might be a runaway multi-line %s string starting on line %d
3671 (S) An advisory indicating that the previous error may have been caused
3672 by a missing delimiter on a string or pattern, because it eventually
3673 ended earlier on the current line.
3675 =item Misplaced _ in number
3677 (W syntax) An underscore (underbar) in a numeric constant did not
3678 separate two digits.
3680 =item Missing argument for %n in %s
3682 (F) A C<%n> was used in a format string with no corresponding argument for
3683 perl to write the current string length to.
3685 =item Missing argument in %s
3687 (W missing) You called a function with fewer arguments than other
3688 arguments you supplied indicated would be needed.
3690 Currently only emitted when a printf-type format required more
3691 arguments than were supplied, but might be used in the future for
3692 other cases where we can statically determine that arguments to
3693 functions are missing, e.g. for the L<perlfunc/pack> function.
3695 =item Missing argument to -%c
3697 (F) The argument to the indicated command line switch must follow
3698 immediately after the switch, without intervening spaces.
3700 =item Missing braces on \N{}
3702 =item Missing braces on \N{} in regex; marked by S<<-- HERE> in m/%s/
3704 (F) Wrong syntax of character name literal C<\N{charname}> within
3705 double-quotish context. This can also happen when there is a space
3706 (or comment) between the C<\N> and the C<{> in a regex with the C</x> modifier.
3707 This modifier does not change the requirement that the brace immediately
3710 =item Missing braces on \o{}
3712 (F) A C<\o> must be followed immediately by a C<{> in double-quotish context.
3714 =item Missing comma after first argument to %s function
3716 (F) While certain functions allow you to specify a filehandle or an
3717 "indirect object" before the argument list, this ain't one of them.
3719 =item Missing command in piped open
3721 (W pipe) You used the C<open(FH, "| command")> or
3722 C<open(FH, "command |")> construction, but the command was missing or
3725 =item Missing control char name in \c
3727 (F) A double-quoted string ended with "\c", without the required control
3730 =item Missing ']' in prototype for %s : %s
3732 (W illegalproto) A grouping was started with C<[> but never closed with C<]>.
3734 =item Missing name in "%s sub"
3736 (F) The syntax for lexically scoped subroutines requires that
3737 they have a name with which they can be found.
3739 =item Missing $ on loop variable
3741 (F) Apparently you've been programming in B<csh> too much. Variables
3742 are always mentioned with the $ in Perl, unlike in the shells, where it
3743 can vary from one line to the next.
3745 =item (Missing operator before %s?)
3747 (S syntax) This is an educated guess made in conjunction with the message
3748 "%s found where operator expected". Often the missing operator is a comma.
3750 =item Missing or undefined argument to %s
3752 (F) You tried to call require or do with no argument or with an undefined
3753 value as an argument. Require expects either a package name or a
3754 file-specification as an argument; do expects a filename. See
3755 L<perlfunc/require EXPR> and L<perlfunc/do EXPR>.
3757 =item Missing right brace on \%c{} in regex; marked by S<<-- HERE> in m/%s/
3759 (F) Missing right brace in C<\x{...}>, C<\p{...}>, C<\P{...}>, or C<\N{...}>.
3761 =item Missing right brace on \N{}
3763 =item Missing right brace on \N{} or unescaped left brace after \N
3765 (F) C<\N> has two meanings.
3767 The traditional one has it followed by a name enclosed in braces,
3768 meaning the character (or sequence of characters) given by that
3769 name. Thus C<\N{ASTERISK}> is another way of writing C<*>, valid in both
3770 double-quoted strings and regular expression patterns. In patterns,
3771 it doesn't have the meaning an unescaped C<*> does.
3773 Starting in Perl 5.12.0, C<\N> also can have an additional meaning (only)
3774 in patterns, namely to match a non-newline character. (This is short
3775 for C<[^\n]>, and like C<.> but is not affected by the C</s> regex modifier.)
3777 This can lead to some ambiguities. When C<\N> is not followed immediately
3778 by a left brace, Perl assumes the C<[^\n]> meaning. Also, if the braces
3779 form a valid quantifier such as C<\N{3}> or C<\N{5,}>, Perl assumes that this
3780 means to match the given quantity of non-newlines (in these examples,
3781 3; and 5 or more, respectively). In all other case, where there is a
3782 C<\N{> and a matching C<}>, Perl assumes that a character name is desired.
3784 However, if there is no matching C<}>, Perl doesn't know if it was
3785 mistakenly omitted, or if C<[^\n]{> was desired, and raises this error.
3786 If you meant the former, add the right brace; if you meant the latter,
3787 escape the brace with a backslash, like so: C<\N\{>
3789 =item Missing right curly or square bracket
3791 (F) The lexer counted more opening curly or square brackets than closing
3792 ones. As a general rule, you'll find it's missing near the place you
3795 =item (Missing semicolon on previous line?)
3797 (S syntax) This is an educated guess made in conjunction with the message
3798 "%s found where operator expected". Don't automatically put a semicolon on
3799 the previous line just because you saw this message.
3801 =item Modification of a read-only value attempted
3803 (F) You tried, directly or indirectly, to change the value of a
3804 constant. You didn't, of course, try "2 = 1", because the compiler
3805 catches that. But an easy way to do the same thing is:
3807 sub mod { $_[0] = 1 }
3810 Another way is to assign to a substr() that's off the end of the string.
3812 Yet another way is to assign to a C<foreach> loop I<VAR> when I<VAR>
3813 is aliased to a constant in the look I<LIST>:
3816 foreach my $n ($x, 2) {
3817 $n *= 2; # modifies the $x, but fails on attempt to
3820 =item Modification of non-creatable array value attempted, %s
3822 (F) You tried to make an array value spring into existence, and the
3823 subscript was probably negative, even counting from end of the array
3826 =item Modification of non-creatable hash value attempted, %s
3828 (P) You tried to make a hash value spring into existence, and it
3829 couldn't be created for some peculiar reason.
3831 =item Module name must be constant
3833 (F) Only a bare module name is allowed as the first argument to a "use".
3835 =item Module name required with -%c option
3837 (F) The C<-M> or C<-m> options say that Perl should load some module, but
3838 you omitted the name of the module. Consult L<perlrun> for full details
3839 about C<-M> and C<-m>.
3841 =item More than one argument to '%s' open
3843 (F) The C<open> function has been asked to open multiple files. This
3844 can happen if you are trying to open a pipe to a command that takes a
3845 list of arguments, but have forgotten to specify a piped open mode.
3846 See L<perlfunc/open> for details.
3848 =item mprotect for COW string %p %u failed with %d
3850 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_COW (see
3851 L<perlguts/"Copy on Write">), but a shared string buffer
3852 could not be made read-only.
3854 =item mprotect for %p %u failed with %d
3856 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_OPS (see L<perlhacktips>),
3857 but an op tree could not be made read-only.
3859 =item mprotect RW for COW string %p %u failed with %d
3861 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_COW (see
3862 L<perlguts/"Copy on Write">), but a read-only shared string
3863 buffer could not be made mutable.
3865 =item mprotect RW for %p %u failed with %d
3867 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_OPS (see
3868 L<perlhacktips>), but a read-only op tree could not be made
3869 mutable before freeing the ops.
3871 =item msg%s not implemented
3873 (F) You don't have System V message IPC on your system.
3875 =item Multidimensional syntax %s not supported
3877 (W syntax) Multidimensional arrays aren't written like C<$foo[1,2,3]>.
3878 They're written like C<$foo[1][2][3]>, as in C.
3880 =item Multiple slurpy parameters not allowed
3882 (F) In subroutine signatures, a slurpy parameter (C<@> or C<%>) must be
3883 the last parameter, and there must not be more than one of them; for
3886 sub foo ($a, @b) {} # legal
3887 sub foo ($a, @b, %) {} # invalid
3889 =item '/' must follow a numeric type in unpack
3891 (F) You had an unpack template that contained a '/', but this did not
3892 follow some unpack specification producing a numeric value.
3893 See L<perlfunc/pack>.
3895 =item %s must not be a named sequence in transliteration operator
3897 (F) Transliteration (C<tr///> and C<y///>) transliterates individual
3898 characters. But a named sequence by definition is more than an
3899 individual character, and hence doing this operation on it doesn't make
3902 =item "my sub" not yet implemented
3904 (F) Lexically scoped subroutines are not yet implemented. Don't try
3907 =item "my" subroutine %s can't be in a package
3909 (F) Lexically scoped subroutines aren't in a package, so it doesn't make
3910 sense to try to declare one with a package qualifier on the front.
3912 =item "my %s" used in sort comparison
3914 (W syntax) The package variables $a and $b are used for sort comparisons.
3915 You used $a or $b in as an operand to the C<< <=> >> or C<cmp> operator inside a
3916 sort comparison block, and the variable had earlier been declared as a
3917 lexical variable. Either qualify the sort variable with the package
3918 name, or rename the lexical variable.
3920 =item "my" variable %s can't be in a package
3922 (F) Lexically scoped variables aren't in a package, so it doesn't make
3923 sense to try to declare one with a package qualifier on the front. Use
3924 local() if you want to localize a package variable.
3926 =item Name "%s::%s" used only once: possible typo
3928 (W once) Typographical errors often show up as unique variable
3929 names. If you had a good reason for having a unique name, then
3930 just mention it again somehow to suppress the message. The C<our>
3931 declaration is also provided for this purpose.
3933 NOTE: This warning detects package symbols that have been used
3934 only once. This means lexical variables will never trigger this
3935 warning. It also means that all of the package variables $c, @c,
3936 %c, as well as *c, &c, sub c{}, c(), and c (the filehandle or
3937 format) are considered the same; if a program uses $c only once
3938 but also uses any of the others it will not trigger this warning.
3939 Symbols beginning with an underscore and symbols using special
3940 identifiers (q.v. L<perldata>) are exempt from this warning.
3942 =item Need exactly 3 octal digits in regex; marked by S<<-- HERE> in m/%s/
3944 (F) Within S<C<(?[ ])>>, all constants interpreted as octal need to be
3945 exactly 3 digits long. This helps catch some ambiguities. If your
3946 constant is too short, add leading zeros, like
3948 (?[ [ \078 ] ]) # Syntax error!
3949 (?[ [ \0078 ] ]) # Works
3950 (?[ [ \007 8 ] ]) # Clearer
3952 The maximum number this construct can express is C<\777>. If you
3953 need a larger one, you need to use L<\o{}|perlrebackslash/Octal escapes> instead. If you meant
3954 two separate things, you need to separate them:
3956 (?[ [ \7776 ] ]) # Syntax error!
3957 (?[ [ \o{7776} ] ]) # One meaning
3958 (?[ [ \777 6 ] ]) # Another meaning
3959 (?[ [ \777 \006 ] ]) # Still another
3961 =item Negative '/' count in unpack
3963 (F) The length count obtained from a length/code unpack operation was
3964 negative. See L<perlfunc/pack>.
3966 =item Negative length
3968 (F) You tried to do a read/write/send/recv operation with a buffer
3969 length that is less than 0. This is difficult to imagine.
3971 =item Negative offset to vec in lvalue context
3973 (F) When C<vec> is called in an lvalue context, the second argument must be
3974 greater than or equal to zero.
3976 =item Negative repeat count does nothing
3978 (W numeric) You tried to execute the
3979 L<C<x>|perlop/Multiplicative Operators> repetition operator fewer than 0
3980 times, which doesn't make sense.
3982 =item Nested quantifiers in regex; marked by S<<-- HERE> in m/%s/
3984 (F) You can't quantify a quantifier without intervening parentheses.
3985 So things like ** or +* or ?* are illegal. The S<<-- HERE> shows
3986 whereabouts in the regular expression the problem was discovered.
3988 Note that the minimal matching quantifiers, C<*?>, C<+?>, and
3989 C<??> appear to be nested quantifiers, but aren't. See L<perlre>.
3991 =item %s never introduced
3993 (S internal) The symbol in question was declared but somehow went out of
3994 scope before it could possibly have been used.
3996 =item next::method/next::can/maybe::next::method cannot find enclosing method
3998 (F) C<next::method> needs to be called within the context of a
3999 real method in a real package, and it could not find such a context.
4002 =item \N in a character class must be a named character: \N{...} in regex;
4003 marked by S<<-- HERE> in m/%s/
4005 (F) The new (as of Perl 5.12) meaning of C<\N> as C<[^\n]> is not valid in a
4006 bracketed character class, for the same reason that C<.> in a character
4007 class loses its specialness: it matches almost everything, which is
4008 probably not what you want.
4010 =item \N{} in inverted character class or as a range end-point is restricted to one character in regex; marked by <-- HERE in m/%s/
4012 (F) Named Unicode character escapes (C<\N{...}>) may return a
4013 multi-character sequence. Even though a character class is
4014 supposed to match just one character of input, perl will match the
4015 whole thing correctly, except under certain conditions. These currently
4020 =item When the class is inverted (C<[^...]>)
4022 The mathematically logical behavior for what matches when inverting
4023 is very different from what people expect, so we have decided to
4026 =item The escape is the beginning or final end point of a range
4028 Similarly unclear is what should be generated when the
4029 C<\N{...}> is used as one of the end points of the range, such as in
4031 [\x{41}-\N{ARABIC SEQUENCE YEH WITH HAMZA ABOVE WITH AE}]
4033 What is meant here is unclear, as the C<\N{...}> escape is a sequence
4034 of code points, so this is made an error.
4036 =item In a regex set
4038 The syntax S<C<(?[ ])>> in a regular expression yields a list of
4039 single code points, none can be a sequence.
4043 =item No %s allowed while running setuid
4045 (F) Certain operations are deemed to be too insecure for a setuid or
4046 setgid script to even be allowed to attempt. Generally speaking there
4047 will be another way to do what you want that is, if not secure, at least
4048 securable. See L<perlsec>.
4050 =item No code specified for -%c
4052 (F) Perl's B<-e> and B<-E> command-line options require an argument. If
4053 you want to run an empty program, pass the empty string as a separate
4054 argument or run a program consisting of a single 0 or 1:
4060 =item No comma allowed after %s
4062 (F) A list operator that has a filehandle or "indirect object" is
4063 not allowed to have a comma between that and the following arguments.
4064 Otherwise it'd be just another one of the arguments.
4066 One possible cause for this is that you expected to have imported
4067 a constant to your name space with B<use> or B<import> while no such
4068 importing took place, it may for example be that your operating
4069 system does not support that particular constant. Hopefully you did
4070 use an explicit import list for the constants you expect to see;
4071 please see L<perlfunc/use> and L<perlfunc/import>. While an
4072 explicit import list would probably have caught this error earlier
4073 it naturally does not remedy the fact that your operating system
4074 still does not support that constant. Maybe you have a typo in
4075 the constants of the symbol import list of B<use> or B<import> or in the
4076 constant name at the line where this error was triggered?
4078 =item No command into which to pipe on command line
4080 (F) An error peculiar to VMS. Perl handles its own command line
4081 redirection, and found a '|' at the end of the command line, so it
4082 doesn't know where you want to pipe the output from this command.
4084 =item No DB::DB routine defined
4086 (F) The currently executing code was compiled with the B<-d> switch, but
4087 for some reason the current debugger (e.g. F<perl5db.pl> or a C<Devel::>
4088 module) didn't define a routine to be called at the beginning of each
4091 =item No dbm on this machine
4093 (P) This is counted as an internal error, because every machine should
4094 supply dbm nowadays, because Perl comes with SDBM. See L<SDBM_File>.
4096 =item No DB::sub routine defined
4098 (F) The currently executing code was compiled with the B<-d> switch, but
4099 for some reason the current debugger (e.g. F<perl5db.pl> or a C<Devel::>
4100 module) didn't define a C<DB::sub> routine to be called at the beginning
4101 of each ordinary subroutine call.
4103 =item No directory specified for -I
4105 (F) The B<-I> command-line switch requires a directory name as part of the
4106 I<same> argument. Use B<-Ilib>, for instance. B<-I lib> won't work.
4108 =item No error file after 2> or 2>> on command line
4110 (F) An error peculiar to VMS. Perl handles its own command line
4111 redirection, and found a '2>' or a '2>>' on the command line, but can't
4112 find the name of the file to which to write data destined for stderr.
4114 =item No group ending character '%c' found in template
4116 (F) A pack or unpack template has an opening '(' or '[' without its
4117 matching counterpart. See L<perlfunc/pack>.
4119 =item No input file after < on command line
4121 (F) An error peculiar to VMS. Perl handles its own command line
4122 redirection, and found a '<' on the command line, but can't find the
4123 name of the file from which to read data for stdin.
4125 =item No next::method '%s' found for %s
4127 (F) C<next::method> found no further instances of this method name
4128 in the remaining packages of the MRO of this class. If you don't want
4129 it throwing an exception, use C<maybe::next::method>
4130 or C<next::can>. See L<mro>.
4132 =item Non-finite repeat count does nothing
4134 (W numeric) You tried to execute the
4135 L<C<x>|perlop/Multiplicative Operators> repetition operator C<Inf> (or
4136 C<-Inf>) or C<NaN> times, which doesn't make sense.
4138 =item Non-hex character in regex; marked by S<<-- HERE> in m/%s/
4140 (F) In a regular expression, there was a non-hexadecimal character where
4141 a hex one was expected, like
4146 =item Non-octal character in regex; marked by S<<-- HERE> in m/%s/
4148 (F) In a regular expression, there was a non-octal character where
4149 an octal one was expected, like
4153 =item Non-octal character '%c'. Resolved as "%s"
4155 (W digit) In parsing an octal numeric constant, a character was
4156 unexpectedly encountered that isn't octal. The resulting value
4159 =item "no" not allowed in expression
4161 (F) The "no" keyword is recognized and executed at compile time, and
4162 returns no useful value. See L<perlmod>.
4164 =item Non-string passed as bitmask
4166 (W misc) A number has been passed as a bitmask argument to select().
4167 Use the vec() function to construct the file descriptor bitmasks for
4168 select. See L<perlfunc/select>.
4170 =item No output file after > on command line
4172 (F) An error peculiar to VMS. Perl handles its own command line
4173 redirection, and found a lone '>' at the end of the command line, so it
4174 doesn't know where you wanted to redirect stdout.
4176 =item No output file after > or >> on command line
4178 (F) An error peculiar to VMS. Perl handles its own command line
4179 redirection, and found a '>' or a '>>' on the command line, but can't
4180 find the name of the file to which to write data destined for stdout.
4182 =item No package name allowed for subroutine %s in "our"
4184 =item No package name allowed for variable %s in "our"
4186 (F) Fully qualified subroutine and variable names are not allowed in "our"
4187 declarations, because that doesn't make much sense under existing rules.
4188 Such syntax is reserved for future extensions.
4190 =item No Perl script found in input
4192 (F) You called C<perl -x>, but no line was found in the file beginning
4193 with #! and containing the word "perl".
4195 =item No setregid available
4197 (F) Configure didn't find anything resembling the setregid() call for
4200 =item No setreuid available
4202 (F) Configure didn't find anything resembling the setreuid() call for
4205 =item No such class %s
4207 (F) You provided a class qualifier in a "my", "our" or "state"
4208 declaration, but this class doesn't exist at this point in your program.
4210 =item No such class field "%s" in variable %s of type %s
4212 (F) You tried to access a key from a hash through the indicated typed
4213 variable but that key is not allowed by the package of the same type.
4214 The indicated package has restricted the set of allowed keys using the
4217 =item No such hook: %s
4219 (F) You specified a signal hook that was not recognized by Perl.
4220 Currently, Perl accepts C<__DIE__> and C<__WARN__> as valid signal hooks.
4222 =item No such pipe open
4224 (P) An error peculiar to VMS. The internal routine my_pclose() tried to
4225 close a pipe which hadn't been opened. This should have been caught
4226 earlier as an attempt to close an unopened filehandle.
4228 =item No such signal: SIG%s
4230 (W signal) You specified a signal name as a subscript to %SIG that was
4231 not recognized. Say C<kill -l> in your shell to see the valid signal
4232 names on your system.
4234 =item No Unicode property value wildcard matches:
4236 (W regexp) You specified a wildcard for a Unicode property value, but
4237 there is no property value in the current Unicode release that matches
4238 it. Check your spelling.
4240 =item Not a CODE reference
4242 (F) Perl was trying to evaluate a reference to a code value (that is, a
4243 subroutine), but found a reference to something else instead. You can
4244 use the ref() function to find out what kind of ref it really was. See
4247 =item Not a GLOB reference
4249 (F) Perl was trying to evaluate a reference to a "typeglob" (that is, a
4250 symbol table entry that looks like C<*foo>), but found a reference to
4251 something else instead. You can use the ref() function to find out what
4252 kind of ref it really was. See L<perlref>.
4254 =item Not a HASH reference
4256 (F) Perl was trying to evaluate a reference to a hash value, but found a
4257 reference to something else instead. You can use the ref() function to
4258 find out what kind of ref it really was. See L<perlref>.
4260 =item '#' not allowed immediately following a sigil in a subroutine signature
4262 (F) In a subroutine signature definition, a comment following a sigil
4263 (C<$>, C<@> or C<%>), needs to be separated by whitespace or a comma etc., in
4264 particular to avoid confusion with the C<$#> variable. For example:
4267 sub f ($# ignore first arg
4270 sub f ($, # ignore first arg
4273 =item Not an ARRAY reference
4275 (F) Perl was trying to evaluate a reference to an array value, but found
4276 a reference to something else instead. You can use the ref() function
4277 to find out what kind of ref it really was. See L<perlref>.
4279 =item Not a SCALAR reference
4281 (F) Perl was trying to evaluate a reference to a scalar value, but found
4282 a reference to something else instead. You can use the ref() function
4283 to find out what kind of ref it really was. See L<perlref>.
4285 =item Not a subroutine reference
4287 (F) Perl was trying to evaluate a reference to a code value (that is, a
4288 subroutine), but found a reference to something else instead. You can
4289 use the ref() function to find out what kind of ref it really was. See
4292 =item Not a subroutine reference in overload table
4294 (F) An attempt was made to specify an entry in an overloading table that
4295 doesn't somehow point to a valid subroutine. See L<overload>.
4297 =item Not enough arguments for %s
4299 (F) The function requires more arguments than you specified.
4301 =item Not enough format arguments
4303 (W syntax) A format specified more picture fields than the next line
4304 supplied. See L<perlform>.
4308 (A) You've accidentally run your script through the Bourne shell instead
4309 of Perl. Check the #! line, or manually feed your script into Perl
4312 =item no UTC offset information; assuming local time is UTC
4314 (S) A warning peculiar to VMS. Perl was unable to find the local
4315 timezone offset, so it's assuming that local system time is equivalent
4316 to UTC. If it's not, define the logical name
4317 F<SYS$TIMEZONE_DIFFERENTIAL> to translate to the number of seconds which
4318 need to be added to UTC to get local time.
4320 =item NULL OP IN RUN
4322 (S debugging) Some internal routine called run() with a null opcode
4325 =item Null picture in formline
4327 (F) The first argument to formline must be a valid format picture
4328 specification. It was found to be empty, which probably means you
4329 supplied it an uninitialized value. See L<perlform>.
4333 (P) An attempt was made to realloc NULL.
4335 =item NULL regexp argument
4337 (P) The internal pattern matching routines blew it big time.
4339 =item NULL regexp parameter
4341 (P) The internal pattern matching routines are out of their gourd.
4343 =item Number too long
4345 (F) Perl limits the representation of decimal numbers in programs to
4346 about 250 characters. You've exceeded that length. Future
4347 versions of Perl are likely to eliminate this arbitrary limitation. In
4348 the meantime, try using scientific notation (e.g. "1e6" instead of
4351 =item Number with no digits
4353 (F) Perl was looking for a number but found nothing that looked like
4354 a number. This happens, for example with C<\o{}>, with no number between
4357 =item Numeric format result too large
4359 (F) The length of the result of a numeric format supplied to sprintf()
4360 or printf() would have been too large for the underlying C function to
4361 report. This limit is typically 2GB.
4363 =item Octal number > 037777777777 non-portable
4365 (W portable) The octal number you specified is larger than 2**32-1
4366 (4294967295) and therefore non-portable between systems. See
4367 L<perlport> for more on portability concerns.
4369 =item Odd name/value argument for subroutine '%s'
4371 (F) A subroutine using a slurpy hash parameter in its signature
4372 received an odd number of arguments to populate the hash. It requires
4373 the arguments to be paired, with the same number of keys as values.
4374 The caller of the subroutine is presumably at fault.
4376 The message attempts to include the name of the called subroutine. If the
4377 subroutine has been aliased, the subroutine's original name will be shown,
4378 regardless of what name the caller used.
4380 =item Odd number of arguments for overload::constant
4382 (W overload) The call to overload::constant contained an odd number of
4383 arguments. The arguments should come in pairs.
4385 =item Odd number of elements in anonymous hash
4387 (W misc) You specified an odd number of elements to initialize a hash,
4388 which is odd, because hashes come in key/value pairs.
4390 =item Odd number of elements in hash assignment
4392 (W misc) You specified an odd number of elements to initialize a hash,
4393 which is odd, because hashes come in key/value pairs.
4395 =item Offset outside string
4397 (F)(W layer) You tried to do a read/write/send/recv/seek operation
4398 with an offset pointing outside the buffer. This is difficult to
4399 imagine. The sole exceptions to this are that zero padding will
4400 take place when going past the end of the string when either
4401 C<sysread()>ing a file, or when seeking past the end of a scalar opened
4402 for I/O (in anticipation of future reads and to imitate the behavior
4405 =item Old package separator used in string
4407 (W syntax) You used the old package separator, "'", in a variable
4408 named inside a double-quoted string; e.g., C<"In $name's house">. This
4409 is equivalent to C<"In $name::s house">. If you meant the former, put
4410 a backslash before the apostrophe (C<"In $name\'s house">).
4412 =item %s() on unopened %s
4414 (W unopened) An I/O operation was attempted on a filehandle that was
4415 never initialized. You need to do an open(), a sysopen(), or a socket()
4416 call, or call a constructor from the FileHandle package.
4418 =item -%s on unopened filehandle %s
4420 (W unopened) You tried to invoke a file test operator on a filehandle
4421 that isn't open. Check your control flow. See also L<perlfunc/-X>.
4425 (S internal) An internal warning that the grammar is screwed up.
4429 (S internal) An internal warning that the grammar is screwed up.
4431 =item Operand with no preceding operator in regex; marked by S<<-- HERE> in
4434 (F) You wrote something like
4436 (?[ \p{Digit} \p{Thai} ])
4438 There are two operands, but no operator giving how you want to combine
4441 =item Operation "%s": no method found, %s
4443 (F) An attempt was made to perform an overloaded operation for which no
4444 handler was defined. While some handlers can be autogenerated in terms
4445 of other handlers, there is no default handler for any operation, unless
4446 the C<fallback> overloading key is specified to be true. See L<overload>.
4448 =item Operation "%s" returns its argument for non-Unicode code point 0x%X
4450 (S non_unicode) You performed an operation requiring Unicode rules
4451 on a code point that is not in Unicode, so what it should do is not
4452 defined. Perl has chosen to have it do nothing, and warn you.
4454 If the operation shown is "ToFold", it means that case-insensitive
4455 matching in a regular expression was done on the code point.
4457 If you know what you are doing you can turn off this warning by
4458 C<no warnings 'non_unicode';>.
4460 =item Operation "%s" returns its argument for UTF-16 surrogate U+%X
4462 (S surrogate) You performed an operation requiring Unicode
4463 rules on a Unicode surrogate. Unicode frowns upon the use
4464 of surrogates for anything but storing strings in UTF-16, but
4465 rules are (reluctantly) defined for the surrogates, and
4466 they are to do nothing for this operation. Because the use of
4467 surrogates can be dangerous, Perl warns.
4469 If the operation shown is "ToFold", it means that case-insensitive
4470 matching in a regular expression was done on the code point.
4472 If you know what you are doing you can turn off this warning by
4473 C<no warnings 'surrogate';>.
4475 =item Operator or semicolon missing before %s
4477 (S ambiguous) You used a variable or subroutine call where the parser
4478 was expecting an operator. The parser has assumed you really meant to
4479 use an operator, but this is highly likely to be incorrect. For
4480 example, if you say "*foo *foo" it will be interpreted as if you said
4483 =item Optional parameter lacks default expression
4485 (F) In a subroutine signature, you wrote something like "$a =", making a
4486 named optional parameter without a default value. A nameless optional
4487 parameter is permitted to have no default value, but a named one must
4488 have a specific default. You probably want "$a = undef".
4490 =item "our" variable %s redeclared
4492 (W shadow) You seem to have already declared the same global once before
4493 in the current lexical scope.
4495 =item Out of memory!
4497 (X) The malloc() function returned 0, indicating there was insufficient
4498 remaining memory (or virtual memory) to satisfy the request. Perl has
4499 no option but to exit immediately.
4501 At least in Unix you may be able to get past this by increasing your
4502 process datasize limits: in csh/tcsh use C<limit> and
4503 C<limit datasize n> (where C<n> is the number of kilobytes) to check
4504 the current limits and change them, and in ksh/bash/zsh use C<ulimit -a>
4505 and C<ulimit -d n>, respectively.
4507 =item Out of memory during %s extend
4509 (X) An attempt was made to extend an array, a list, or a string beyond
4510 the largest possible memory allocation.
4512 =item Out of memory during "large" request for %s
4514 (F) The malloc() function returned 0, indicating there was insufficient
4515 remaining memory (or virtual memory) to satisfy the request. However,
4516 the request was judged large enough (compile-time default is 64K), so a
4517 possibility to shut down by trapping this error is granted.
4519 =item Out of memory during request for %s
4521 (X)(F) The malloc() function returned 0, indicating there was
4522 insufficient remaining memory (or virtual memory) to satisfy the
4525 The request was judged to be small, so the possibility to trap it
4526 depends on the way perl was compiled. By default it is not trappable.
4527 However, if compiled for this, Perl may use the contents of C<$^M> as an
4528 emergency pool after die()ing with this message. In this case the error
4529 is trappable I<once>, and the error message will include the line and file
4530 where the failed request happened.
4532 =item Out of memory during ridiculously large request
4534 (F) You can't allocate more than 2^31+"small amount" bytes. This error
4535 is most likely to be caused by a typo in the Perl program. e.g.,
4536 C<$arr[time]> instead of C<$arr[$time]>.
4538 =item Out of memory for yacc stack
4540 (F) The yacc parser wanted to grow its stack so it could continue
4541 parsing, but realloc() wouldn't give it more memory, virtual or
4544 =item '.' outside of string in pack
4546 (F) The argument to a '.' in your template tried to move the working
4547 position to before the start of the packed string being built.
4549 =item '@' outside of string in unpack
4551 (F) You had a template that specified an absolute position outside
4552 the string being unpacked. See L<perlfunc/pack>.
4554 =item '@' outside of string with malformed UTF-8 in unpack
4556 (F) You had a template that specified an absolute position outside
4557 the string being unpacked. The string being unpacked was also invalid
4558 UTF-8. See L<perlfunc/pack>.
4560 =item overload arg '%s' is invalid
4562 (W overload) The L<overload> pragma was passed an argument it did not
4563 recognize. Did you mistype an operator?
4565 =item Overloaded dereference did not return a reference
4567 (F) An object with an overloaded dereference operator was dereferenced,
4568 but the overloaded operation did not return a reference. See
4571 =item Overloaded qr did not return a REGEXP
4573 (F) An object with a C<qr> overload was used as part of a match, but the
4574 overloaded operation didn't return a compiled regexp. See L<overload>.
4576 =item %s package attribute may clash with future reserved word: %s
4578 (W reserved) A lowercase attribute name was used that had a
4579 package-specific handler. That name might have a meaning to Perl itself
4580 some day, even though it doesn't yet. Perhaps you should use a
4581 mixed-case attribute name, instead. See L<attributes>.
4583 =item pack/unpack repeat count overflow
4585 (F) You can't specify a repeat count so large that it overflows your
4586 signed integers. See L<perlfunc/pack>.
4590 (W io) A single call to write() produced more lines than can fit on a
4591 page. See L<perlform>.
4595 (P) An internal error.
4597 =item panic: attempt to call %s in %s
4599 (P) One of the file test operators entered a code branch that calls
4600 an ACL related-function, but that function is not available on this
4601 platform. Earlier checks mean that it should not be possible to
4602 enter this branch on this platform.
4604 =item panic: child pseudo-process was never scheduled
4606 (P) A child pseudo-process in the ithreads implementation on Windows
4607 was not scheduled within the time period allowed and therefore was not
4608 able to initialize properly.
4610 =item panic: ck_grep, type=%u
4612 (P) Failed an internal consistency check trying to compile a grep.
4614 =item panic: corrupt saved stack index %ld
4616 (P) The savestack was requested to restore more localized values than
4617 there are in the savestack.
4619 =item panic: del_backref
4621 (P) Failed an internal consistency check while trying to reset a weak
4624 =item panic: do_subst
4626 (P) The internal pp_subst() routine was called with invalid operational
4629 =item panic: do_trans_%s
4631 (P) The internal do_trans routines were called with invalid operational
4634 =item panic: fold_constants JMPENV_PUSH returned %d
4636 (P) While attempting folding constants an exception other than an C<eval>
4639 =item panic: frexp: %f
4641 (P) The library function frexp() failed, making printf("%f") impossible.
4643 =item panic: goto, type=%u, ix=%ld
4645 (P) We popped the context stack to a context with the specified label,
4646 and then discovered it wasn't a context we know how to do a goto in.
4648 =item panic: gp_free failed to free glob pointer
4650 (P) The internal routine used to clear a typeglob's entries tried
4651 repeatedly, but each time something re-created entries in the glob.
4652 Most likely the glob contains an object with a reference back to
4653 the glob and a destructor that adds a new object to the glob.
4655 =item panic: INTERPCASEMOD, %s
4657 (P) The lexer got into a bad state at a case modifier.
4659 =item panic: INTERPCONCAT, %s
4661 (P) The lexer got into a bad state parsing a string with brackets.
4663 =item panic: kid popen errno read
4665 (F) A forked child returned an incomprehensible message about its errno.
4667 =item panic: last, type=%u
4669 (P) We popped the context stack to a block context, and then discovered
4670 it wasn't a block context.
4672 =item panic: leave_scope clearsv
4674 (P) A writable lexical variable became read-only somehow within the
4677 =item panic: leave_scope inconsistency %u
4679 (P) The savestack probably got out of sync. At least, there was an
4680 invalid enum on the top of it.
4682 =item panic: magic_killbackrefs
4684 (P) Failed an internal consistency check while trying to reset all weak
4685 references to an object.
4687 =item panic: malloc, %s
4689 (P) Something requested a negative number of bytes of malloc.
4691 =item panic: memory wrap
4693 (P) Something tried to allocate either more memory than possible or a
4696 =item panic: pad_alloc, %p!=%p
4698 (P) The compiler got confused about which scratch pad it was allocating
4699 and freeing temporaries and lexicals from.
4701 =item panic: pad_free curpad, %p!=%p
4703 (P) The compiler got confused about which scratch pad it was allocating
4704 and freeing temporaries and lexicals from.
4706 =item panic: pad_free po
4708 (P) A zero scratch pad offset was detected internally. An attempt was
4709 made to free a target that had not been allocated to begin with.
4711 =item panic: pad_reset curpad, %p!=%p
4713 (P) The compiler got confused about which scratch pad it was allocating
4714 and freeing temporaries and lexicals from.
4716 =item panic: pad_sv po
4718 (P) A zero scratch pad offset was detected internally. Most likely
4719 an operator needed a target but that target had not been allocated
4720 for whatever reason.
4722 =item panic: pad_swipe curpad, %p!=%p
4724 (P) The compiler got confused about which scratch pad it was allocating
4725 and freeing temporaries and lexicals from.
4727 =item panic: pad_swipe po
4729 (P) An invalid scratch pad offset was detected internally.
4731 =item panic: pp_iter, type=%u
4733 (P) The foreach iterator got called in a non-loop context frame.
4735 =item panic: pp_match%s
4737 (P) The internal pp_match() routine was called with invalid operational
4740 =item panic: realloc, %s
4742 (P) Something requested a negative number of bytes of realloc.
4744 =item panic: reference miscount on nsv in sv_replace() (%d != 1)
4746 (P) The internal sv_replace() function was handed a new SV with a
4747 reference count other than 1.
4749 =item panic: restartop in %s
4751 (P) Some internal routine requested a goto (or something like it), and
4752 didn't supply the destination.
4754 =item panic: return, type=%u
4756 (P) We popped the context stack to a subroutine or eval context, and
4757 then discovered it wasn't a subroutine or eval context.
4759 =item panic: scan_num, %s
4761 (P) scan_num() got called on something that wasn't a number.
4763 =item panic: Sequence (?{...}): no code block found in regex m/%s/
4765 (P) While compiling a pattern that has embedded (?{}) or (??{}) code
4766 blocks, perl couldn't locate the code block that should have already been
4767 seen and compiled by perl before control passed to the regex compiler.
4769 =item panic: strxfrm() gets absurd - a => %u, ab => %u
4771 (P) The interpreter's sanity check of the C function strxfrm() failed.
4772 In your current locale the returned transformation of the string "ab"
4773 is shorter than that of the string "a", which makes no sense.
4775 =item panic: sv_chop %s
4777 (P) The sv_chop() routine was passed a position that is not within the
4778 scalar's string buffer.
4780 =item panic: sv_insert, midend=%p, bigend=%p
4782 (P) The sv_insert() routine was told to remove more string than there
4785 =item panic: top_env
4787 (P) The compiler attempted to do a goto, or something weird like that.
4789 =item panic: unimplemented op %s (#%d) called
4791 (P) The compiler is screwed up and attempted to use an op that isn't
4792 permitted at run time.
4794 =item panic: unknown OA_*: %x
4796 (P) The internal routine that handles arguments to C<&CORE::foo()>
4797 subroutine calls was unable to determine what type of arguments
4800 =item panic: utf16_to_utf8: odd bytelen
4802 (P) Something tried to call utf16_to_utf8 with an odd (as opposed
4803 to even) byte length.
4805 =item panic: utf16_to_utf8_reversed: odd bytelen
4807 (P) Something tried to call utf16_to_utf8_reversed with an odd (as opposed
4808 to even) byte length.
4810 =item panic: yylex, %s
4812 (P) The lexer got into a bad state while processing a case modifier.
4814 =item Parentheses missing around "%s" list
4816 (W parenthesis) You said something like
4822 my ($foo, $bar) = @_;
4824 Remember that "my", "our", "local" and "state" bind tighter than comma.
4826 =item Parsing code internal error (%s)
4828 (F) Parsing code supplied by an extension violated the parser's API in
4831 =item Pattern subroutine nesting without pos change exceeded limit in regex
4833 (F) You used a pattern that uses too many nested subpattern calls without
4834 consuming any text. Restructure the pattern so text is consumed before
4835 the nesting limit is exceeded.
4837 =item C<-p> destination: %s
4839 (F) An error occurred during the implicit output invoked by the C<-p>
4840 command-line switch. (This output goes to STDOUT unless you've
4841 redirected it with select().)
4843 =item Perl API version %s of %s does not match %s
4845 (F) The XS module in question was compiled against a different incompatible
4846 version of Perl than the one that has loaded the XS module.
4848 =item Perl folding rules are not up-to-date for 0x%X; please use the perlbug
4849 utility to report; in regex; marked by S<<-- HERE> in m/%s/
4851 (S regexp) You used a regular expression with case-insensitive matching,
4852 and there is a bug in Perl in which the built-in regular expression
4853 folding rules are not accurate. This may lead to incorrect results.
4854 Please report this as a bug using the L<perlbug> utility.
4856 =item PerlIO layer ':win32' is experimental
4858 (S experimental::win32_perlio) The C<:win32> PerlIO layer is
4859 experimental. If you want to take the risk of using this layer,
4860 simply disable this warning:
4862 no warnings "experimental::win32_perlio";
4864 =item Perl_my_%s() not available
4866 (F) Your platform has very uncommon byte-order and integer size,
4867 so it was not possible to set up some or all fixed-width byte-order
4868 conversion functions. This is only a problem when you're using the
4869 '<' or '>' modifiers in (un)pack templates. See L<perlfunc/pack>.
4871 =item Perl %s required (did you mean %s?)--this is only %s, stopped
4873 (F) The code you are trying to run has asked for a newer version of
4874 Perl than you are running. Perhaps C<use 5.10> was written instead
4875 of C<use 5.010> or C<use v5.10>. Without the leading C<v>, the number is
4876 interpreted as a decimal, with every three digits after the
4877 decimal point representing a part of the version number. So 5.10
4878 is equivalent to v5.100.
4880 =item Perl %s required--this is only %s, stopped
4882 (F) The module in question uses features of a version of Perl more
4883 recent than the currently running version. How long has it been since
4884 you upgraded, anyway? See L<perlfunc/require>.
4886 =item PERL_SH_DIR too long
4888 (F) An error peculiar to OS/2. PERL_SH_DIR is the directory to find the
4889 C<sh>-shell in. See "PERL_SH_DIR" in L<perlos2>.
4891 =item PERL_SIGNALS illegal: "%s"
4893 (X) See L<perlrun/PERL_SIGNALS> for legal values.
4895 =item Perls since %s too modern--this is %s, stopped
4897 (F) The code you are trying to run claims it will not run
4898 on the version of Perl you are using because it is too new.
4899 Maybe the code needs to be updated, or maybe it is simply
4900 wrong and the version check should just be removed.
4902 =item perl: warning: Non hex character in '$ENV{PERL_HASH_SEED}', seed only partially set
4904 (S) PERL_HASH_SEED should match /^\s*(?:0x)?[0-9a-fA-F]+\s*\z/ but it
4905 contained a non hex character. This could mean you are not using the
4906 hash seed you think you are.
4908 =item perl: warning: Setting locale failed.
4910 (S) The whole warning message will look something like:
4912 perl: warning: Setting locale failed.
4913 perl: warning: Please check that your locale settings:
4916 are supported and installed on your system.
4917 perl: warning: Falling back to the standard locale ("C").
4919 Exactly what were the failed locale settings varies. In the above the
4920 settings were that the LC_ALL was "En_US" and the LANG had no value.
4921 This error means that Perl detected that you and/or your operating
4922 system supplier and/or system administrator have set up the so-called
4923 locale system but Perl could not use those settings. This was not
4924 dead serious, fortunately: there is a "default locale" called "C" that
4925 Perl can and will use, and the script will be run. Before you really
4926 fix the problem, however, you will get the same error message each
4927 time you run Perl. How to really fix the problem can be found in
4928 L<perllocale> section B<LOCALE PROBLEMS>.
4930 =item perl: warning: strange setting in '$ENV{PERL_PERTURB_KEYS}': '%s'
4932 (S) Perl was run with the environment variable PERL_PERTURB_KEYS defined
4933 but containing an unexpected value. The legal values of this setting
4936 Numeric | String | Result
4937 --------+---------------+-----------------------------------------
4938 0 | NO | Disables key traversal randomization
4939 1 | RANDOM | Enables full key traversal randomization
4940 2 | DETERMINISTIC | Enables repeatable key traversal
4943 Both numeric and string values are accepted, but note that string values are
4944 case sensitive. The default for this setting is "RANDOM" or 1.
4946 =item pid %x not a child
4948 (W exec) A warning peculiar to VMS. Waitpid() was asked to wait for a
4949 process which isn't a subprocess of the current process. While this is
4950 fine from VMS' perspective, it's probably not what you intended.
4952 =item 'P' must have an explicit size in unpack
4954 (F) The unpack format P must have an explicit size, not "*".
4956 =item POSIX class [:%s:] unknown in regex; marked by S<<-- HERE> in m/%s/
4958 (F) The class in the character class [: :] syntax is unknown. The S<<-- HERE>
4959 shows whereabouts in the regular expression the problem was discovered.
4960 Note that the POSIX character classes do B<not> have the C<is> prefix
4961 the corresponding C interfaces have: in other words, it's C<[[:print:]]>,
4962 not C<isprint>. See L<perlre>.
4964 =item POSIX getpgrp can't take an argument
4966 (F) Your system has POSIX getpgrp(), which takes no argument, unlike
4967 the BSD version, which takes a pid.
4969 =item POSIX syntax [%c %c] belongs inside character classes%s in regex; marked by
4970 S<<-- HERE> in m/%s/
4972 (W regexp) Perl thinks that you intended to write a POSIX character
4973 class, but didn't use enough brackets. These POSIX class constructs [:
4974 :], [= =], and [. .] go I<inside> character classes, the [] are part of
4975 the construct, for example: C<qr/[012[:alpha:]345]/>. What the regular
4976 expression pattern compiled to is probably not what you were intending.
4977 For example, C<qr/[:alpha:]/> compiles to a regular bracketed character
4978 class consisting of the four characters C<":">, C<"a">, C<"l">,
4979 C<"h">, and C<"p">. To specify the POSIX class, it should have been
4980 written C<qr/[[:alpha:]]/>.
4982 Note that [= =] and [. .] are not currently
4983 implemented; they are simply placeholders for future extensions and
4984 will cause fatal errors. The S<<-- HERE> shows whereabouts in the regular
4985 expression the problem was discovered. See L<perlre>.
4987 If the specification of the class was not completely valid, the message
4990 =item POSIX syntax [. .] is reserved for future extensions in regex; marked by
4991 S<<-- HERE> in m/%s/
4993 (F) Within regular expression character classes ([]) the syntax beginning
4994 with "[." and ending with ".]" is reserved for future extensions. If you
4995 need to represent those character sequences inside a regular expression
4996 character class, just quote the square brackets with the backslash: "\[."
4997 and ".\]". The S<<-- HERE> shows whereabouts in the regular expression the
4998 problem was discovered. See L<perlre>.
5000 =item POSIX syntax [= =] is reserved for future extensions in regex; marked by
5001 S<<-- HERE> in m/%s/
5003 (F) Within regular expression character classes ([]) the syntax beginning
5004 with "[=" and ending with "=]" is reserved for future extensions. If you
5005 need to represent those character sequences inside a regular expression
5006 character class, just quote the square brackets with the backslash: "\[="
5007 and "=\]". The S<<-- HERE> shows whereabouts in the regular expression the
5008 problem was discovered. See L<perlre>.
5010 =item Possible attempt to put comments in qw() list
5012 (W qw) qw() lists contain items separated by whitespace; as with literal
5013 strings, comment characters are not ignored, but are instead treated as
5014 literal data. (You may have used different delimiters than the
5015 parentheses shown here; braces are also frequently used.)
5017 You probably wrote something like this:
5024 when you should have written this:
5031 If you really want comments, build your list the
5032 old-fashioned way, with quotes and commas:
5036 'b', # another comment
5039 =item Possible attempt to separate words with commas
5041 (W qw) qw() lists contain items separated by whitespace; therefore
5042 commas aren't needed to separate the items. (You may have used
5043 different delimiters than the parentheses shown here; braces are also
5046 You probably wrote something like this:
5050 which puts literal commas into some of the list items. Write it without
5051 commas if you don't want them to appear in your data:
5055 =item Possible memory corruption: %s overflowed 3rd argument
5057 (F) An ioctl() or fcntl() returned more than Perl was bargaining for.
5058 Perl guesses a reasonable buffer size, but puts a sentinel byte at the
5059 end of the buffer just in case. This sentinel byte got clobbered, and
5060 Perl assumes that memory is now corrupted. See L<perlfunc/ioctl>.
5062 =item Possible precedence issue with control flow operator
5064 (W syntax) There is a possible problem with the mixing of a control
5065 flow operator (e.g. C<return>) and a low-precedence operator like
5068 sub { return $a or $b; }
5072 sub { (return $a) or $b; }
5074 Which is effectively just:
5078 Either use parentheses or the high-precedence variant of the operator.
5080 Note this may be also triggered for constructs like:
5084 =item Possible precedence problem on bitwise %s operator
5086 (W precedence) Your program uses a bitwise logical operator in conjunction
5087 with a numeric comparison operator, like this :
5089 if ($x & $y == 0) { ... }
5091 This expression is actually equivalent to C<$x & ($y == 0)>, due to the
5092 higher precedence of C<==>. This is probably not what you want. (If you
5093 really meant to write this, disable the warning, or, better, put the
5094 parentheses explicitly and write C<$x & ($y == 0)>).
5096 =item Possible unintended interpolation of $\ in regex
5098 (W ambiguous) You said something like C<m/$\/> in a regex.
5099 The regex C<m/foo$\s+bar/m> translates to: match the word 'foo', the output
5100 record separator (see L<perlvar/$\>) and the letter 's' (one time or more)
5101 followed by the word 'bar'.
5103 If this is what you intended then you can silence the warning by using
5104 C<m/${\}/> (for example: C<m/foo${\}s+bar/>).
5106 If instead you intended to match the word 'foo' at the end of the line
5107 followed by whitespace and the word 'bar' on the next line then you can use
5108 C<m/$(?)\/> (for example: C<m/foo$(?)\s+bar/>).
5110 =item Possible unintended interpolation of %s in string
5112 (W ambiguous) You said something like '@foo' in a double-quoted string
5113 but there was no array C<@foo> in scope at the time. If you wanted a
5114 literal @foo, then write it as \@foo; otherwise find out what happened
5115 to the array you apparently lost track of.
5117 =item Precedence problem: open %s should be open(%s)
5119 (S precedence) The old irregular construct
5123 is now misinterpreted as
5127 because of the strict regularization of Perl 5's grammar into unary and
5128 list operators. (The old open was a little of both.) You must put
5129 parentheses around the filehandle, or use the new "or" operator instead
5132 =item Premature end of script headers
5134 See L</500 Server error>.
5136 =item printf() on closed filehandle %s
5138 (W closed) The filehandle you're writing to got itself closed sometime
5139 before now. Check your control flow.
5141 =item print() on closed filehandle %s
5143 (W closed) The filehandle you're printing on got itself closed sometime
5144 before now. Check your control flow.
5146 =item Process terminated by SIG%s
5148 (W) This is a standard message issued by OS/2 applications, while *nix
5149 applications die in silence. It is considered a feature of the OS/2
5150 port. One can easily disable this by appropriate sighandlers, see
5151 L<perlipc/"Signals">. See also "Process terminated by SIGTERM/SIGINT"
5154 =item Prototype after '%c' for %s : %s
5156 (W illegalproto) A character follows % or @ in a prototype. This is
5157 useless, since % and @ gobble the rest of the subroutine arguments.
5159 =item Prototype mismatch: %s vs %s
5161 (S prototype) The subroutine being declared or defined had previously been
5162 declared or defined with a different function prototype.
5164 =item Prototype not terminated
5166 (F) You've omitted the closing parenthesis in a function prototype
5169 =item Prototype '%s' overridden by attribute 'prototype(%s)' in %s
5171 (W prototype) A prototype was declared in both the parentheses after
5172 the sub name and via the prototype attribute. The prototype in
5173 parentheses is useless, since it will be replaced by the prototype
5174 from the attribute before it's ever used.
5176 =item Quantifier follows nothing in regex; marked by S<<-- HERE> in m/%s/
5178 (F) You started a regular expression with a quantifier. Backslash it if
5179 you meant it literally. The S<<-- HERE> shows whereabouts in the regular
5180 expression the problem was discovered. See L<perlre>.
5182 =item Quantifier in {,} bigger than %d in regex; marked by S<<-- HERE> in m/%s/
5184 (F) There is currently a limit to the size of the min and max values of
5185 the {min,max} construct. The S<<-- HERE> shows whereabouts in the regular
5186 expression the problem was discovered. See L<perlre>.
5188 =item Quantifier {n,m} with n > m can't match in regex
5190 =item Quantifier {n,m} with n > m can't match in regex; marked by
5191 S<<-- HERE> in m/%s/
5193 (W regexp) Minima should be less than or equal to maxima. If you really
5194 want your regexp to match something 0 times, just put {0}.
5196 =item Quantifier unexpected on zero-length expression in regex m/%s/
5198 (W regexp) You applied a regular expression quantifier in a place where
5199 it makes no sense, such as on a zero-width assertion. Try putting the
5200 quantifier inside the assertion instead. For example, the way to match
5201 "abc" provided that it is followed by three repetitions of "xyz" is
5202 C</abc(?=(?:xyz){3})/>, not C</abc(?=xyz){3}/>.
5204 =item Range iterator outside integer range
5206 (F) One (or both) of the numeric arguments to the range operator ".."
5207 are outside the range which can be represented by integers internally.
5208 One possible workaround is to force Perl to use magical string increment
5209 by prepending "0" to your numbers.
5211 =item Ranges of ASCII printables should be some subset of "0-9", "A-Z", or
5212 "a-z" in regex; marked by S<<-- HERE> in m/%s/
5214 (W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
5216 Stricter rules help to find typos and other errors. Perhaps you didn't
5217 even intend a range here, if the C<"-"> was meant to be some other
5218 character, or should have been escaped (like C<"\-">). If you did
5219 intend a range, the one that was used is not portable between ASCII and
5220 EBCDIC platforms, and doesn't have an obvious meaning to a casual
5223 [3-7] # OK; Obvious and portable
5224 [d-g] # OK; Obvious and portable
5225 [A-Y] # OK; Obvious and portable
5226 [A-z] # WRONG; Not portable; not clear what is meant
5227 [a-Z] # WRONG; Not portable; not clear what is meant
5228 [%-.] # WRONG; Not portable; not clear what is meant
5229 [\x41-Z] # WRONG; Not portable; not obvious to non-geek
5231 (You can force portability by specifying a Unicode range, which means that
5232 the endpoints are specified by
5233 L<C<\N{...}>|perlrecharclass/Character Ranges>, but the meaning may
5234 still not be obvious.)
5235 The stricter rules require that ranges that start or stop with an ASCII
5236 character that is not a control have all their endpoints be the literal
5237 character, and not some escape sequence (like C<"\x41">), and the ranges
5238 must be all digits, or all uppercase letters, or all lowercase letters.
5240 =item Ranges of digits should be from the same group in regex; marked by
5241 S<<-- HERE> in m/%s/
5243 (W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
5245 Stricter rules help to find typos and other errors. You included a
5246 range, and at least one of the end points is a decimal digit. Under the
5247 stricter rules, when this happens, both end points should be digits in
5248 the same group of 10 consecutive digits.
5250 =item readdir() attempted on invalid dirhandle %s
5252 (W io) The dirhandle you're reading from is either closed or not really
5253 a dirhandle. Check your control flow.
5255 =item readline() on closed filehandle %s
5257 (W closed) The filehandle you're reading from got itself closed sometime
5258 before now. Check your control flow.
5260 =item read() on closed filehandle %s
5262 (W closed) You tried to read from a closed filehandle.
5264 =item read() on unopened filehandle %s
5266 (W unopened) You tried to read from a filehandle that was never opened.
5268 =item Reallocation too large: %x
5270 (F) You can't allocate more than 64K on an MS-DOS machine.
5272 =item realloc() of freed memory ignored
5274 (S malloc) An internal routine called realloc() on something that had
5277 =item Recompile perl with B<-D>DEBUGGING to use B<-D> switch
5279 (S debugging) You can't use the B<-D> option unless the code to produce
5280 the desired output is compiled into Perl, which entails some overhead,
5281 which is why it's currently left out of your copy.
5283 =item Recursive call to Perl_load_module in PerlIO_find_layer
5285 (P) It is currently not permitted to load modules when creating
5286 a filehandle inside an %INC hook. This can happen with C<open my
5287 $fh, '<', \$scalar>, which implicitly loads PerlIO::scalar. Try
5288 loading PerlIO::scalar explicitly first.
5290 =item Recursive inheritance detected in package '%s'
5292 (F) While calculating the method resolution order (MRO) of a package, Perl
5293 believes it found an infinite loop in the C<@ISA> hierarchy. This is a
5294 crude check that bails out after 100 levels of C<@ISA> depth.
5296 =item Redundant argument in %s
5298 (W redundant) You called a function with more arguments than other
5299 arguments you supplied indicated would be needed. Currently only
5300 emitted when a printf-type format required fewer arguments than were
5301 supplied, but might be used in the future for e.g. L<perlfunc/pack>.
5303 =item refcnt_dec: fd %d%s
5305 =item refcnt: fd %d%s
5307 =item refcnt_inc: fd %d%s
5309 (P) Perl's I/O implementation failed an internal consistency check. If
5310 you see this message, something is very wrong.
5312 =item Reference found where even-sized list expected
5314 (W misc) You gave a single reference where Perl was expecting a list
5315 with an even number of elements (for assignment to a hash). This
5316 usually means that you used the anon hash constructor when you meant
5317 to use parens. In any case, a hash requires key/value B<pairs>.
5319 %hash = { one => 1, two => 2, }; # WRONG
5320 %hash = [ qw/ an anon array / ]; # WRONG
5321 %hash = ( one => 1, two => 2, ); # right
5322 %hash = qw( one 1 two 2 ); # also fine
5324 =item Reference is already weak
5326 (W misc) You have attempted to weaken a reference that is already weak.
5327 Doing so has no effect.
5329 =item Reference is not weak
5331 (W misc) You have attempted to unweaken a reference that is not weak.
5332 Doing so has no effect.
5334 =item Reference to invalid group 0 in regex; marked by S<<-- HERE> in m/%s/
5336 (F) You used C<\g0> or similar in a regular expression. You may refer
5337 to capturing parentheses only with strictly positive integers
5338 (normal backreferences) or with strictly negative integers (relative
5339 backreferences). Using 0 does not make sense.
5341 =item Reference to nonexistent group in regex; marked by S<<-- HERE> in
5344 (F) You used something like C<\7> in your regular expression, but there are
5345 not at least seven sets of capturing parentheses in the expression. If
5346 you wanted to have the character with ordinal 7 inserted into the regular
5347 expression, prepend zeroes to make it three digits long: C<\007>
5349 The S<<-- HERE> shows whereabouts in the regular expression the problem was
5352 =item Reference to nonexistent named group in regex; marked by S<<-- HERE>
5355 (F) You used something like C<\k'NAME'> or C<< \k<NAME> >> in your regular
5356 expression, but there is no corresponding named capturing parentheses
5357 such as C<(?'NAME'...)> or C<< (?<NAME>...) >>. Check if the name has been
5358 spelled correctly both in the backreference and the declaration.
5360 The S<<-- HERE> shows whereabouts in the regular expression the problem was
5363 =item Reference to nonexistent or unclosed group in regex; marked by
5364 S<<-- HERE> in m/%s/
5366 (F) You used something like C<\g{-7}> in your regular expression, but there
5367 are not at least seven sets of closed capturing parentheses in the
5368 expression before where the C<\g{-7}> was located.
5370 The S<<-- HERE> shows whereabouts in the regular expression the problem was
5373 =item regexp memory corruption
5375 (P) The regular expression engine got confused by what the regular
5376 expression compiler gave it.
5378 =item Regexp modifier "/%c" may appear a maximum of twice
5380 =item Regexp modifier "%c" may appear a maximum of twice in regex; marked
5381 by S<<-- HERE> in m/%s/
5383 (F) The regular expression pattern had too many occurrences
5384 of the specified modifier. Remove the extraneous ones.
5386 =item Regexp modifier "%c" may not appear after the "-" in regex; marked by <--
5389 (F) Turning off the given modifier has the side effect of turning on
5390 another one. Perl currently doesn't allow this. Reword the regular
5391 expression to use the modifier you want to turn on (and place it before
5392 the minus), instead of the one you want to turn off.
5394 =item Regexp modifier "/%c" may not appear twice
5396 =item Regexp modifier "%c" may not appear twice in regex; marked by <--
5399 (F) The regular expression pattern had too many occurrences
5400 of the specified modifier. Remove the extraneous ones.
5402 =item Regexp modifiers "/%c" and "/%c" are mutually exclusive
5404 =item Regexp modifiers "%c" and "%c" are mutually exclusive in regex;
5405 marked by S<<-- HERE> in m/%s/
5407 (F) The regular expression pattern had more than one of these
5408 mutually exclusive modifiers. Retain only the modifier that is
5409 supposed to be there.
5411 =item Regexp out of space in regex m/%s/
5413 (P) A "can't happen" error, because safemalloc() should have caught it
5416 =item Repeated format line will never terminate (~~ and @#)
5418 (F) Your format contains the ~~ repeat-until-blank sequence and a
5419 numeric field that will never go blank so that the repetition never
5420 terminates. You might use ^# instead. See L<perlform>.
5422 =item Replacement list is longer than search list
5424 (W misc) You have used a replacement list that is longer than the
5425 search list. So the additional elements in the replacement list
5428 =item '(*%s' requires a terminating ':' in regex; marked by <-- HERE in m/%s/
5430 (F) You used a construct that needs a colon and pattern argument.
5431 Supply these or check that you are using the right construct.
5433 =item '%s' resolved to '\o{%s}%d'
5435 (W misc, regexp) You wrote something like C<\08>, or C<\179> in a
5436 double-quotish string. All but the last digit is treated as a single
5437 character, specified in octal. The last digit is the next character in
5438 the string. To tell Perl that this is indeed what you want, you can use
5439 the C<\o{ }> syntax, or use exactly three digits to specify the octal
5442 =item Reversed %s= operator
5444 (W syntax) You wrote your assignment operator backwards. The = must
5445 always come last, to avoid ambiguity with subsequent unary operators.
5447 =item rewinddir() attempted on invalid dirhandle %s
5449 (W io) The dirhandle you tried to do a rewinddir() on is either closed
5450 or not really a dirhandle. Check your control flow.
5452 =item Scalars leaked: %d
5454 (S internal) Something went wrong in Perl's internal bookkeeping
5455 of scalars: not all scalar variables were deallocated by the time
5456 Perl exited. What this usually indicates is a memory leak, which
5457 is of course bad, especially if the Perl program is intended to be
5460 =item Scalar value @%s[%s] better written as $%s[%s]
5462 (W syntax) You've used an array slice (indicated by @) to select a
5463 single element of an array. Generally it's better to ask for a scalar
5464 value (indicated by $). The difference is that C<$foo[&bar]> always
5465 behaves like a scalar, both when assigning to it and when evaluating its
5466 argument, while C<@foo[&bar]> behaves like a list when you assign to it,
5467 and provides a list context to its subscript, which can do weird things
5468 if you're expecting only one subscript.
5470 On the other hand, if you were actually hoping to treat the array
5471 element as a list, you need to look into how references work, because
5472 Perl will not magically convert between scalars and lists for you. See
5475 =item Scalar value @%s{%s} better written as $%s{%s}
5477 (W syntax) You've used a hash slice (indicated by @) to select a single
5478 element of a hash. Generally it's better to ask for a scalar value
5479 (indicated by $). The difference is that C<$foo{&bar}> always behaves
5480 like a scalar, both when assigning to it and when evaluating its
5481 argument, while C<@foo{&bar}> behaves like a list when you assign to it,
5482 and provides a list context to its subscript, which can do weird things
5483 if you're expecting only one subscript.
5485 On the other hand, if you were actually hoping to treat the hash element
5486 as a list, you need to look into how references work, because Perl will
5487 not magically convert between scalars and lists for you. See
5490 =item Search pattern not terminated
5492 (F) The lexer couldn't find the final delimiter of a // or m{}
5493 construct. Remember that bracketing delimiters count nesting level.
5494 Missing the leading C<$> from a variable C<$m> may cause this error.
5496 Note that since Perl 5.10.0 a // can also be the I<defined-or>
5497 construct, not just the empty search pattern. Therefore code written
5498 in Perl 5.10.0 or later that uses the // as the I<defined-or> can be
5499 misparsed by pre-5.10.0 Perls as a non-terminated search pattern.
5501 =item seekdir() attempted on invalid dirhandle %s
5503 (W io) The dirhandle you are doing a seekdir() on is either closed or not
5504 really a dirhandle. Check your control flow.
5506 =item %sseek() on unopened filehandle
5508 (W unopened) You tried to use the seek() or sysseek() function on a
5509 filehandle that was either never opened or has since been closed.
5511 =item select not implemented
5513 (F) This machine doesn't implement the select() system call.
5515 =item Self-ties of arrays and hashes are not supported
5517 (F) Self-ties are of arrays and hashes are not supported in
5518 the current implementation.
5520 =item Semicolon seems to be missing
5522 (W semicolon) A nearby syntax error was probably caused by a missing
5523 semicolon, or possibly some other missing operator, such as a comma.
5525 =item semi-panic: attempt to dup freed string
5527 (S internal) The internal newSVsv() routine was called to duplicate a
5528 scalar that had previously been marked as free.
5530 =item sem%s not implemented
5532 (F) You don't have System V semaphore IPC on your system.
5534 =item send() on closed socket %s
5536 (W closed) The socket you're sending to got itself closed sometime
5537 before now. Check your control flow.
5539 =item Sequence "\c{" invalid
5541 (F) These three characters may not appear in sequence in a
5542 double-quotish context. This message is raised only on non-ASCII
5543 platforms (a different error message is output on ASCII ones). If you
5544 were intending to specify a control character with this sequence, you'll
5545 have to use a different way to specify it.
5547 =item Sequence (? incomplete in regex; marked by S<<-- HERE> in m/%s/
5549 (F) A regular expression ended with an incomplete extension (?. The
5550 S<<-- HERE> shows whereabouts in the regular expression the problem was
5551 discovered. See L<perlre>.
5553 =item Sequence (?%c...) not implemented in regex; marked by S<<-- HERE> in
5556 (F) A proposed regular expression extension has the character reserved
5557 but has not yet been written. The S<<-- HERE> shows whereabouts in the
5558 regular expression the problem was discovered. See L<perlre>.
5560 =item Sequence (?%s...) not recognized in regex; marked by S<<-- HERE> in
5563 (F) You used a regular expression extension that doesn't make sense.
5564 The S<<-- HERE> shows whereabouts in the regular expression the problem was
5565 discovered. This may happen when using the C<(?^...)> construct to tell
5566 Perl to use the default regular expression modifiers, and you
5567 redundantly specify a default modifier. For other
5568 causes, see L<perlre>.
5570 =item Sequence (?#... not terminated in regex m/%s/
5572 (F) A regular expression comment must be terminated by a closing
5573 parenthesis. Embedded parentheses aren't allowed. See
5576 =item Sequence (?&... not terminated in regex; marked by S<<-- HERE> in
5579 (F) A named reference of the form C<(?&...)> was missing the final
5580 closing parenthesis after the name. The S<<-- HERE> shows whereabouts
5581 in the regular expression the problem was discovered.
5583 =item Sequence (?%c... not terminated in regex; marked by S<<-- HERE>
5586 (F) A named group of the form C<(?'...')> or C<< (?<...>) >> was missing the final
5587 closing quote or angle bracket. The S<<-- HERE> shows whereabouts in the
5588 regular expression the problem was discovered.
5590 =item Sequence (?(%c... not terminated in regex; marked by S<<-- HERE>
5593 (F) A named reference of the form C<(?('...')...)> or C<< (?(<...>)...) >> was
5594 missing the final closing quote or angle bracket after the name. The
5595 S<<-- HERE> shows whereabouts in the regular expression the problem was
5598 =item Sequence (?... not terminated in regex; marked by S<<-- HERE> in
5601 (F) There was no matching closing parenthesis for the '('. The
5602 S<<-- HERE> shows whereabouts in the regular expression the problem was
5605 =item Sequence \%s... not terminated in regex; marked by S<<-- HERE> in
5608 (F) The regular expression expects a mandatory argument following the escape
5609 sequence and this has been omitted or incorrectly written.
5611 =item Sequence (?{...}) not terminated with ')'
5613 (F) The end of the perl code contained within the {...} must be
5614 followed immediately by a ')'.
5616 =item Sequence (?PE<gt>... not terminated in regex; marked by S<<-- HERE> in m/%s/
5618 (F) A named reference of the form C<(?PE<gt>...)> was missing the final
5619 closing parenthesis after the name. The S<<-- HERE> shows whereabouts
5620 in the regular expression the problem was discovered.
5622 =item Sequence (?PE<lt>... not terminated in regex; marked by S<<-- HERE> in m/%s/
5624 (F) A named group of the form C<(?PE<lt>...E<gt>')> was missing the final
5625 closing angle bracket. The S<<-- HERE> shows whereabouts in the
5626 regular expression the problem was discovered.
5628 =item Sequence ?P=... not terminated in regex; marked by S<<-- HERE> in
5631 (F) A named reference of the form C<(?P=...)> was missing the final
5632 closing parenthesis after the name. The S<<-- HERE> shows whereabouts
5633 in the regular expression the problem was discovered.
5635 =item Sequence (?R) not terminated in regex m/%s/
5637 (F) An C<(?R)> or C<(?0)> sequence in a regular expression was missing the
5640 =item Z<>500 Server error
5642 (A) This is the error message generally seen in a browser window
5643 when trying to run a CGI program (including SSI) over the web. The
5644 actual error text varies widely from server to server. The most
5645 frequently-seen variants are "500 Server error", "Method (something)
5646 not permitted", "Document contains no data", "Premature end of script
5647 headers", and "Did not produce a valid header".
5649 B<This is a CGI error, not a Perl error>.
5651 You need to make sure your script is executable, is accessible by
5652 the user CGI is running the script under (which is probably not the
5653 user account you tested it under), does not rely on any environment
5654 variables (like PATH) from the user it isn't running under, and isn't
5655 in a location where the CGI server can't find it, basically, more or
5656 less. Please see the following for more information:
5658 http://www.perl.org/CGI_MetaFAQ.html
5659 http://www.htmlhelp.org/faq/cgifaq.html
5660 http://www.w3.org/Security/Faq/
5662 You should also look at L<perlfaq9>.
5664 =item setegid() not implemented
5666 (F) You tried to assign to C<$)>, and your operating system doesn't
5667 support the setegid() system call (or equivalent), or at least Configure
5670 =item seteuid() not implemented
5672 (F) You tried to assign to C<< $> >>, and your operating system doesn't
5673 support the seteuid() system call (or equivalent), or at least Configure
5676 =item setpgrp can't take arguments
5678 (F) Your system has the setpgrp() from BSD 4.2, which takes no
5679 arguments, unlike POSIX setpgid(), which takes a process ID and process
5682 =item setrgid() not implemented
5684 (F) You tried to assign to C<$(>, and your operating system doesn't
5685 support the setrgid() system call (or equivalent), or at least Configure
5688 =item setruid() not implemented
5690 (F) You tried to assign to C<$<>, and your operating system doesn't
5691 support the setruid() system call (or equivalent), or at least Configure
5694 =item setsockopt() on closed socket %s
5696 (W closed) You tried to set a socket option on a closed socket. Did you
5697 forget to check the return value of your socket() call? See
5698 L<perlfunc/setsockopt>.
5700 =item Setting $/ to a reference to %s is forbidden
5702 (F) You assigned a reference to a scalar to C<$/> where the referenced item is
5703 not a positive integer. In older perls this B<appeared> to work the same as
5704 setting it to C<undef> but was in fact internally different, less efficient
5705 and with very bad luck could have resulted in your file being split by a
5706 stringified form of the reference.
5708 In Perl 5.20.0 this was changed so that it would be B<exactly> the same as
5709 setting C<$/> to undef, with the exception that this warning would be thrown.
5711 You are recommended to change your code to set C<$/> to C<undef> explicitly if
5712 you wish to slurp the file. As of Perl 5.28 assigning C<$/> to a reference
5713 to an integer which isn't positive is a fatal error.
5715 =item Setting $/ to %s reference is forbidden
5717 (F) You tried to assign a reference to a non integer to C<$/>. In older
5718 Perls this would have behaved similarly to setting it to a reference to
5719 a positive integer, where the integer was the address of the reference.
5720 As of Perl 5.20.0 this is a fatal error, to allow future versions of Perl
5721 to use non-integer refs for more interesting purposes.
5723 =item shm%s not implemented
5725 (F) You don't have System V shared memory IPC on your system.
5727 =item !=~ should be !~
5729 (W syntax) The non-matching operator is !~, not !=~. !=~ will be
5730 interpreted as the != (numeric not equal) and ~ (1's complement)
5731 operators: probably not what you intended.
5733 =item /%s/ should probably be written as "%s"
5735 (W syntax) You have used a pattern where Perl expected to find a string,
5736 as in the first argument to C<join>. Perl will treat the true or false
5737 result of matching the pattern against $_ as the string, which is
5738 probably not what you had in mind.
5740 =item shutdown() on closed socket %s
5742 (W closed) You tried to do a shutdown on a closed socket. Seems a bit
5745 =item SIG%s handler "%s" not defined
5747 (W signal) The signal handler named in %SIG doesn't, in fact, exist.
5748 Perhaps you put it into the wrong package?
5750 =item Slab leaked from cv %p
5752 (S) If you see this message, then something is seriously wrong with the
5753 internal bookkeeping of op trees. An op tree needed to be freed after
5754 a compilation error, but could not be found, so it was leaked instead.
5756 =item sleep(%u) too large
5758 (W overflow) You called C<sleep> with a number that was larger than
5759 it can reliably handle and C<sleep> probably slept for less time than
5762 =item Slurpy parameter not last
5764 (F) In a subroutine signature, you put something after a slurpy (array or
5765 hash) parameter. The slurpy parameter takes all the available arguments,
5766 so there can't be any left to fill later parameters.
5768 =item Smart matching a non-overloaded object breaks encapsulation
5770 (F) You should not use the C<~~> operator on an object that does not
5771 overload it: Perl refuses to use the object's underlying structure
5772 for the smart match.
5774 =item Smartmatch is experimental
5776 (S experimental::smartmatch) This warning is emitted if you
5777 use the smartmatch (C<~~>) operator. This is currently an experimental
5778 feature, and its details are subject to change in future releases of
5779 Perl. Particularly, its current behavior is noticed for being
5780 unnecessarily complex and unintuitive, and is very likely to be
5783 =item Sorry, hash keys must be smaller than 2**31 bytes
5785 (F) You tried to create a hash containing a very large key, where "very
5786 large" means that it needs at least 2 gigabytes to store. Unfortunately,
5787 Perl doesn't yet handle such large hash keys. You should
5788 reconsider your design to avoid hashing such a long string directly.
5790 =item sort is now a reserved word
5792 (F) An ancient error message that almost nobody ever runs into anymore.
5793 But before sort was a keyword, people sometimes used it as a filehandle.
5795 =item Source filters apply only to byte streams
5797 (F) You tried to activate a source filter (usually by loading a
5798 source filter module) within a string passed to C<eval>. This is
5799 not permitted under the C<unicode_eval> feature. Consider using
5800 C<evalbytes> instead. See L<feature>.
5802 =item splice() offset past end of array
5804 (W misc) You attempted to specify an offset that was past the end of
5805 the array passed to splice(). Splicing will instead commence at the
5806 end of the array, rather than past it. If this isn't what you want,
5807 try explicitly pre-extending the array by assigning $#array = $offset.
5808 See L<perlfunc/splice>.
5812 (P) The split was looping infinitely. (Obviously, a split shouldn't
5813 iterate more times than there are characters of input, which is what
5814 happened.) See L<perlfunc/split>.
5816 =item Statement unlikely to be reached
5818 (W exec) You did an exec() with some statement after it other than a
5819 die(). This is almost always an error, because exec() never returns
5820 unless there was a failure. You probably wanted to use system()
5821 instead, which does return. To suppress this warning, put the exec() in
5824 =item "state" subroutine %s can't be in a package
5826 (F) Lexically scoped subroutines aren't in a package, so it doesn't make
5827 sense to try to declare one with a package qualifier on the front.
5829 =item "state %s" used in sort comparison
5831 (W syntax) The package variables $a and $b are used for sort comparisons.
5832 You used $a or $b in as an operand to the C<< <=> >> or C<cmp> operator inside a
5833 sort comparison block, and the variable had earlier been declared as a
5834 lexical variable. Either qualify the sort variable with the package
5835 name, or rename the lexical variable.
5837 =item "state" variable %s can't be in a package
5839 (F) Lexically scoped variables aren't in a package, so it doesn't make
5840 sense to try to declare one with a package qualifier on the front. Use
5841 local() if you want to localize a package variable.
5843 =item stat() on unopened filehandle %s
5845 (W unopened) You tried to use the stat() function on a filehandle that
5846 was either never opened or has since been closed.
5848 =item Strings with code points over 0xFF may not be mapped into in-memory file handles
5850 (W utf8) You tried to open a reference to a scalar for read or append
5851 where the scalar contained code points over 0xFF. In-memory files
5852 model on-disk files and can only contain bytes.
5854 =item Stub found while resolving method "%s" overloading "%s" in package "%s"
5856 (P) Overloading resolution over @ISA tree may be broken by importation
5857 stubs. Stubs should never be implicitly created, but explicit calls to
5858 C<can> may break this.
5860 =item Subroutine attributes must come before the signature
5862 (F) When subroutine signatures are enabled, any subroutine attributes must
5863 come before the signature. Note that this order was the opposite in
5864 versions 5.22..5.26. So:
5866 sub foo :lvalue ($a, $b) { ... } # 5.20 and 5.28 +
5867 sub foo ($a, $b) :lvalue { ... } # 5.22 .. 5.26
5869 =item Subroutine "&%s" is not available
5871 (W closure) During compilation, an inner named subroutine or eval is
5872 attempting to capture an outer lexical subroutine that is not currently
5873 available. This can happen for one of two reasons. First, the lexical
5874 subroutine may be declared in an outer anonymous subroutine that has
5875 not yet been created. (Remember that named subs are created at compile
5876 time, while anonymous subs are created at run-time.) For example,
5878 sub { my sub a {...} sub f { \&a } }
5880 At the time that f is created, it can't capture the current "a" sub,
5881 since the anonymous subroutine hasn't been created yet. Conversely, the
5882 following won't give a warning since the anonymous subroutine has by now
5883 been created and is live:
5885 sub { my sub a {...} eval 'sub f { \&a }' }->();
5887 The second situation is caused by an eval accessing a lexical subroutine
5888 that has gone out of scope, for example,
5896 Here, when the '\&a' in the eval is being compiled, f() is not currently
5897 being executed, so its &a is not available for capture.
5899 =item "%s" subroutine &%s masks earlier declaration in same %s
5901 (W shadow) A "my" or "state" subroutine has been redeclared in the
5902 current scope or statement, effectively eliminating all access to
5903 the previous instance. This is almost always a typographical error.
5904 Note that the earlier subroutine will still exist until the end of
5905 the scope or until all closure references to it are destroyed.
5907 =item Subroutine %s redefined
5909 (W redefine) You redefined a subroutine. To suppress this warning, say
5912 no warnings 'redefine';
5913 eval "sub name { ... }";
5916 =item Subroutine "%s" will not stay shared
5918 (W closure) An inner (nested) I<named> subroutine is referencing a "my"
5919 subroutine defined in an outer named subroutine.
5921 When the inner subroutine is called, it will see the value of the outer
5922 subroutine's lexical subroutine as it was before and during the *first*
5923 call to the outer subroutine; in this case, after the first call to the
5924 outer subroutine is complete, the inner and outer subroutines will no
5925 longer share a common value for the lexical subroutine. In other words,
5926 it will no longer be shared. This will especially make a difference
5927 if the lexical subroutines accesses lexical variables declared in its
5930 This problem can usually be solved by making the inner subroutine
5931 anonymous, using the C<sub {}> syntax. When inner anonymous subs that
5932 reference lexical subroutines in outer subroutines are created, they
5933 are automatically rebound to the current values of such lexical subs.
5935 =item Substitution loop
5937 (P) The substitution was looping infinitely. (Obviously, a substitution
5938 shouldn't iterate more times than there are characters of input, which
5939 is what happened.) See the discussion of substitution in
5940 L<perlop/"Regexp Quote-Like Operators">.
5942 =item Substitution pattern not terminated
5944 (F) The lexer couldn't find the interior delimiter of an s/// or s{}{}
5945 construct. Remember that bracketing delimiters count nesting level.
5946 Missing the leading C<$> from variable C<$s> may cause this error.
5948 =item Substitution replacement not terminated
5950 (F) The lexer couldn't find the final delimiter of an s/// or s{}{}
5951 construct. Remember that bracketing delimiters count nesting level.
5952 Missing the leading C<$> from variable C<$s> may cause this error.
5954 =item substr outside of string
5956 (W substr)(F) You tried to reference a substr() that pointed outside of
5957 a string. That is, the absolute value of the offset was larger than the
5958 length of the string. See L<perlfunc/substr>. This warning is fatal if
5959 substr is used in an lvalue context (as the left hand side of an
5960 assignment or as a subroutine argument for example).
5962 =item sv_upgrade from type %d down to type %d
5964 (P) Perl tried to force the upgrade of an SV to a type which was actually
5965 inferior to its current type.
5967 =item SWASHNEW didn't return an HV ref
5969 (P) Something went wrong internally when Perl was trying to look up
5972 =item Switch (?(condition)... contains too many branches in regex; marked by
5973 S<<-- HERE> in m/%s/
5975 (F) A (?(condition)if-clause|else-clause) construct can have at most
5976 two branches (the if-clause and the else-clause). If you want one or
5977 both to contain alternation, such as using C<this|that|other>, enclose
5978 it in clustering parentheses:
5980 (?(condition)(?:this|that|other)|else-clause)
5982 The S<<-- HERE> shows whereabouts in the regular expression the problem
5983 was discovered. See L<perlre>.
5985 =item Switch condition not recognized in regex; marked by S<<-- HERE> in
5988 (F) The condition part of a (?(condition)if-clause|else-clause) construct
5989 is not known. The condition must be one of the following:
5991 (1) (2) ... true if 1st, 2nd, etc., capture matched
5992 (<NAME>) ('NAME') true if named capture matched
5993 (?=...) (?<=...) true if subpattern matches
5994 (?!...) (?<!...) true if subpattern fails to match
5995 (?{ CODE }) true if code returns a true value
5996 (R) true if evaluating inside recursion
5997 (R1) (R2) ... true if directly inside capture group 1, 2, etc.
5998 (R&NAME) true if directly inside named capture
5999 (DEFINE) always false; for defining named subpatterns
6001 The S<<-- HERE> shows whereabouts in the regular expression the problem was
6002 discovered. See L<perlre>.
6004 =item Switch (?(condition)... not terminated in regex; marked by
6005 S<<-- HERE> in m/%s/
6007 (F) You omitted to close a (?(condition)...) block somewhere
6008 in the pattern. Add a closing parenthesis in the appropriate
6009 position. See L<perlre>.
6011 =item switching effective %s is not implemented
6013 (F) While under the C<use filetest> pragma, we cannot switch the real
6014 and effective uids or gids.
6018 (F) Probably means you had a syntax error. Common reasons include:
6020 A keyword is misspelled.
6021 A semicolon is missing.
6023 An opening or closing parenthesis is missing.
6024 An opening or closing brace is missing.
6025 A closing quote is missing.
6027 Often there will be another error message associated with the syntax
6028 error giving more information. (Sometimes it helps to turn on B<-w>.)
6029 The error message itself often tells you where it was in the line when
6030 it decided to give up. Sometimes the actual error is several tokens
6031 before this, because Perl is good at understanding random input.
6032 Occasionally the line number may be misleading, and once in a blue moon
6033 the only way to figure out what's triggering the error is to call
6034 C<perl -c> repeatedly, chopping away half the program each time to see
6035 if the error went away. Sort of the cybernetic version of S<20 questions>.
6037 =item syntax error at line %d: '%s' unexpected
6039 (A) You've accidentally run your script through the Bourne shell instead
6040 of Perl. Check the #! line, or manually feed your script into Perl
6043 =item syntax error in file %s at line %d, next 2 tokens "%s"
6045 (F) This error is likely to occur if you run a perl5 script through
6046 a perl4 interpreter, especially if the next 2 tokens are "use strict"
6047 or "my $var" or "our $var".
6049 =item Syntax error in (?[...]) in regex; marked by <-- HERE in m/%s/
6051 (F) Perl could not figure out what you meant inside this construct; this
6052 notifies you that it is giving up trying.
6056 (F) The final summary message when a C<perl -c> succeeds.
6058 =item sysread() on closed filehandle %s
6060 (W closed) You tried to read from a closed filehandle.
6062 =item sysread() on unopened filehandle %s
6064 (W unopened) You tried to read from a filehandle that was never opened.
6066 =item System V %s is not implemented on this machine
6068 (F) You tried to do something with a function beginning with "sem",
6069 "shm", or "msg" but that System V IPC is not implemented in your
6070 machine. In some machines the functionality can exist but be
6071 unconfigured. Consult your system support.
6073 =item syswrite() on closed filehandle %s
6075 (W closed) The filehandle you're writing to got itself closed sometime
6076 before now. Check your control flow.
6078 =item C<-T> and C<-B> not implemented on filehandles
6080 (F) Perl can't peek at the stdio buffer of filehandles when it doesn't
6081 know about your kind of stdio. You'll have to use a filename instead.
6083 =item Target of goto is too deeply nested
6085 (F) You tried to use C<goto> to reach a label that was too deeply nested
6086 for Perl to reach. Perl is doing you a favor by refusing.
6088 =item telldir() attempted on invalid dirhandle %s
6090 (W io) The dirhandle you tried to telldir() is either closed or not really
6091 a dirhandle. Check your control flow.
6093 =item tell() on unopened filehandle
6095 (W unopened) You tried to use the tell() function on a filehandle that
6096 was either never opened or has since been closed.
6098 =item The alpha_assertions feature is experimental
6100 (S experimental::alpha_assertions) This feature is experimental
6101 and its behavior may change in any future release of perl. See
6102 L<perlre/Extended Patterns>.
6104 =item The crypt() function is unimplemented due to excessive paranoia.
6106 (F) Configure couldn't find the crypt() function on your machine,
6107 probably because your vendor didn't supply it, probably because they
6108 think the U.S. Government thinks it's a secret, or at least that they
6109 will continue to pretend that it is. And if you quote me on that, I
6112 =item The experimental declared_refs feature is not enabled
6114 (F) To declare references to variables, as in C<my \%x>, you must first enable
6117 no warnings "experimental::declared_refs";
6118 use feature "declared_refs";
6120 =item The %s function is unimplemented
6122 (F) The function indicated isn't implemented on this architecture,
6123 according to the probings of Configure.
6125 =item The private_use feature is experimental
6127 (S experimental::private_use) This feature is actually a hook for future
6130 =item The regex_sets feature is experimental
6132 (S experimental::regex_sets) This warning is emitted if you
6133 use the syntax S<C<(?[ ])>> in a regular expression.
6134 The details of this feature are subject to change.
6135 If you want to use it, but know that in doing so you
6136 are taking the risk of using an experimental feature which may
6137 change in a future Perl version, you can do this to silence the
6140 no warnings "experimental::regex_sets";
6142 =item The script_run feature is experimental
6144 (S experimental::script_run) This feature is experimental
6145 and its behavior may in any future release of perl. See
6146 L<perlre/Script Runs>.
6148 =item The signatures feature is experimental
6150 (S experimental::signatures) This warning is emitted if you unwrap a
6151 subroutine's arguments using a signature. Simply suppress the warning
6152 if you want to use the feature, but know that in doing so you are taking
6153 the risk of using an experimental feature which may change or be removed
6154 in a future Perl version:
6156 no warnings "experimental::signatures";
6157 use feature "signatures";
6158 sub foo ($left, $right) { ... }
6160 =item The stat preceding %s wasn't an lstat
6162 (F) It makes no sense to test the current stat buffer for symbolic
6163 linkhood if the last stat that wrote to the stat buffer already went
6164 past the symlink to get to the real file. Use an actual filename
6167 =item The Unicode property wildcards feature is experimental
6169 (S experimental::uniprop_wildcards) This feature is experimental
6170 and its behavior may in any future release of perl. See
6171 L<perlunicode/Wildcards in Property Values>.
6173 =item The 'unique' attribute may only be applied to 'our' variables
6175 (F) This attribute was never supported on C<my> or C<sub> declarations.
6177 =item This Perl can't reset CRTL environ elements (%s)
6179 =item This Perl can't set CRTL environ elements (%s=%s)
6181 (W internal) Warnings peculiar to VMS. You tried to change or delete an
6182 element of the CRTL's internal environ array, but your copy of Perl
6183 wasn't built with a CRTL that contained the setenv() function. You'll
6184 need to rebuild Perl with a CRTL that does, or redefine
6185 F<PERL_ENV_TABLES> (see L<perlvms>) so that the environ array isn't the
6186 target of the change to
6187 %ENV which produced the warning.
6189 =item This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().
6191 (F) Something has attempted to use an internal API call which
6192 depends on Perl being compiled with the default support for randomized hash
6193 key traversal, but this Perl has been compiled without it. You should
6194 report this warning to the relevant upstream party, or recompile perl
6195 with default options.
6197 =item This use of my() in false conditional is no longer allowed
6199 (F) You used a declaration similar to C<my $x if 0>. There
6200 has been a long-standing bug in Perl that causes a lexical variable
6201 not to be cleared at scope exit when its declaration includes a false
6202 conditional. Some people have exploited this bug to achieve a kind of
6203 static variable. Since we intend to fix this bug, we don't want people
6204 relying on this behavior. You can achieve a similar static effect by
6205 declaring the variable in a separate block outside the function, eg
6207 sub f { my $x if 0; return $x++ }
6211 { my $x; sub f { return $x++ } }
6213 Beginning with perl 5.10.0, you can also use C<state> variables to have
6214 lexicals that are initialized only once (see L<feature>):
6216 sub f { state $x; return $x++ }
6218 This use of C<my()> in a false conditional was deprecated beginning in
6219 Perl 5.10 and became a fatal error in Perl 5.30.
6221 =item times not implemented
6223 (F) Your version of the C library apparently doesn't do times(). I
6224 suspect you're not running on Unix.
6226 =item "-T" is on the #! line, it must also be used on the command line
6228 (X) The #! line (or local equivalent) in a Perl script contains
6229 the B<-T> option (or the B<-t> option), but Perl was not invoked with
6230 B<-T> in its command line. This is an error because, by the time
6231 Perl discovers a B<-T> in a script, it's too late to properly taint
6232 everything from the environment. So Perl gives up.
6234 If the Perl script is being executed as a command using the #!
6235 mechanism (or its local equivalent), this error can usually be
6236 fixed by editing the #! line so that the B<-%c> option is a part of
6237 Perl's first argument: e.g. change C<perl -n -%c> to C<perl -%c -n>.
6239 If the Perl script is being executed as C<perl scriptname>, then the
6240 B<-%c> option must appear on the command line: C<perl -%c scriptname>.
6242 =item To%s: illegal mapping '%s'
6244 (F) You tried to define a customized To-mapping for lc(), lcfirst,
6245 uc(), or ucfirst() (or their string-inlined versions), but you
6246 specified an illegal mapping.
6247 See L<perlunicode/"User-Defined Character Properties">.
6249 =item Too deeply nested ()-groups
6251 (F) Your template contains ()-groups with a ridiculously deep nesting level.
6253 =item Too few args to syscall
6255 (F) There has to be at least one argument to syscall() to specify the
6256 system call to call, silly dilly.
6258 =item Too few arguments for subroutine '%s'
6260 (F) A subroutine using a signature fewer arguments than required by the
6261 signature. The caller of the subroutine is presumably at fault.
6263 The message attempts to include the name of the called subroutine. If
6264 the subroutine has been aliased, the subroutine's original name will be
6265 shown, regardless of what name the caller used.
6267 =item Too late for "-%s" option
6269 (X) The #! line (or local equivalent) in a Perl script contains the
6270 B<-M>, B<-m> or B<-C> option.
6272 In the case of B<-M> and B<-m>, this is an error because those options
6273 are not intended for use inside scripts. Use the C<use> pragma instead.
6275 The B<-C> option only works if it is specified on the command line as
6276 well (with the same sequence of letters or numbers following). Either
6277 specify this option on the command line, or, if your system supports
6278 it, make your script executable and run it directly instead of passing
6281 =item Too late to run %s block
6283 (W void) A CHECK or INIT block is being defined during run time proper,
6284 when the opportunity to run them has already passed. Perhaps you are
6285 loading a file with C<require> or C<do> when you should be using C<use>
6286 instead. Or perhaps you should put the C<require> or C<do> inside a
6289 =item Too many args to syscall
6291 (F) Perl supports a maximum of only 14 args to syscall().
6293 =item Too many arguments for %s
6295 (F) The function requires fewer arguments than you specified.
6297 =item Too many arguments for subroutine '%s'
6299 (F) A subroutine using a signature received more arguments than permitted
6300 by the signature. The caller of the subroutine is presumably at fault.
6302 The message attempts to include the name of the called subroutine. If the
6303 subroutine has been aliased, the subroutine's original name will be shown,
6304 regardless of what name the caller used.
6306 =item Too many nested open parens in regex; marked by <-- HERE in m/%s/
6308 (F) You have exceeded the number of open C<"("> parentheses that haven't
6309 been matched by corresponding closing ones. This limit prevents eating
6310 up too much memory. It is initially set to 1000, but may be changed by
6311 setting C<${^RE_COMPILE_RECURSION_LIMIT}> to some other value. This may
6312 need to be done in a BEGIN block before the regular expression pattern
6317 (A) You've accidentally run your script through B<csh> instead of Perl.
6318 Check the #! line, or manually feed your script into Perl yourself.
6322 (A) You've accidentally run your script through B<csh> instead of Perl.
6323 Check the #! line, or manually feed your script into Perl yourself.
6325 =item Trailing \ in regex m/%s/
6327 (F) The regular expression ends with an unbackslashed backslash.
6328 Backslash it. See L<perlre>.
6330 =item Transliteration pattern not terminated
6332 (F) The lexer couldn't find the interior delimiter of a tr/// or tr[][]
6333 or y/// or y[][] construct. Missing the leading C<$> from variables
6334 C<$tr> or C<$y> may cause this error.
6336 =item Transliteration replacement not terminated
6338 (F) The lexer couldn't find the final delimiter of a tr///, tr[][],
6339 y/// or y[][] construct.
6341 =item '%s' trapped by operation mask
6343 (F) You tried to use an operator from a Safe compartment in which it's
6344 disallowed. See L<Safe>.
6346 =item truncate not implemented
6348 (F) Your machine doesn't implement a file truncation mechanism that
6349 Configure knows about.
6351 =item Type of arg %d to &CORE::%s must be %s
6353 (F) The subroutine in question in the CORE package requires its argument
6354 to be a hard reference to data of the specified type. Overloading is
6355 ignored, so a reference to an object that is not the specified type, but
6356 nonetheless has overloading to handle it, will still not be accepted.
6358 =item Type of arg %d to %s must be %s (not %s)
6360 (F) This function requires the argument in that position to be of a
6361 certain type. Arrays must be @NAME or C<@{EXPR}>. Hashes must be
6362 %NAME or C<%{EXPR}>. No implicit dereferencing is allowed--use the
6363 {EXPR} forms as an explicit dereference. See L<perlref>.
6365 =item umask not implemented
6367 (F) Your machine doesn't implement the umask function and you tried to
6368 use it to restrict permissions for yourself (EXPR & 0700).
6370 =item Unbalanced context: %d more PUSHes than POPs
6372 (S internal) The exit code detected an internal inconsistency in how
6373 many execution contexts were entered and left.
6375 =item Unbalanced saves: %d more saves than restores
6377 (S internal) The exit code detected an internal inconsistency in how
6378 many values were temporarily localized.
6380 =item Unbalanced scopes: %d more ENTERs than LEAVEs
6382 (S internal) The exit code detected an internal inconsistency in how
6383 many blocks were entered and left.
6385 =item Unbalanced string table refcount: (%d) for "%s"
6387 (S internal) On exit, Perl found some strings remaining in the shared
6388 string table used for copy on write and for hash keys. The entries
6389 should have been freed, so this indicates a bug somewhere.
6391 =item Unbalanced tmps: %d more allocs than frees
6393 (S internal) The exit code detected an internal inconsistency in how
6394 many mortal scalars were allocated and freed.
6396 =item Undefined format "%s" called
6398 (F) The format indicated doesn't seem to exist. Perhaps it's really in
6399 another package? See L<perlform>.
6401 =item Undefined sort subroutine "%s" called
6403 (F) The sort comparison routine specified doesn't seem to exist.
6404 Perhaps it's in a different package? See L<perlfunc/sort>.
6406 =item Undefined subroutine &%s called
6408 (F) The subroutine indicated hasn't been defined, or if it was, it has
6409 since been undefined.
6411 =item Undefined subroutine called
6413 (F) The anonymous subroutine you're trying to call hasn't been defined,
6414 or if it was, it has since been undefined.
6416 =item Undefined subroutine in sort
6418 (F) The sort comparison routine specified is declared but doesn't seem
6419 to have been defined yet. See L<perlfunc/sort>.
6421 =item Undefined top format "%s" called
6423 (F) The format indicated doesn't seem to exist. Perhaps it's really in
6424 another package? See L<perlform>.
6426 =item Undefined value assigned to typeglob
6428 (W misc) An undefined value was assigned to a typeglob, a la
6429 C<*foo = undef>. This does nothing. It's possible that you really mean
6432 =item %s: Undefined variable
6434 (A) You've accidentally run your script through B<csh> instead of Perl.
6435 Check the #! line, or manually feed your script into Perl yourself.
6437 =item Unescaped left brace in regex is passed through in regex; marked by S<<-- HERE> in m/%s/
6439 (W regexp) The simple rule to remember, if you want to
6440 match a literal C<"{"> character (U+007B C<LEFT CURLY BRACKET>) in a
6441 regular expression pattern, is to escape each literal instance of it in
6442 some way. Generally easiest is to precede it with a backslash, like
6443 C<"\{"> or enclose it in square brackets (C<"[{]">). If the pattern
6444 delimiters are also braces, any matching right brace (C<"}">) should
6445 also be escaped to avoid confusing the parser, for example,
6449 Forcing literal C<"{"> characters to be escaped will enable the Perl
6450 language to be extended in various ways in future releases. To avoid
6451 needlessly breaking existing code, the restriction is is not enforced in
6452 contexts where there are unlikely to ever be extensions that could
6453 conflict with the use there of C<"{"> as a literal. Those that are
6454 not potentially ambiguous do not warn; those that are do raise a
6455 non-deprecation warning.
6457 In this release of Perl, some literal uses of C<"{"> are fatal, and some
6458 still just deprecated. This is because of an oversight: some uses of a
6459 literal C<"{"> that should have raised a deprecation warning starting in
6460 v5.20 did not warn until v5.26. By making the already-warned uses fatal
6461 now, some of the planned extensions can be made to the language sooner.
6462 The cases which are still allowed will be fatal in Perl 5.32.
6464 The contexts where no warnings or errors are raised are:
6470 as the first character in a pattern, or following C<"^"> indicating to
6471 anchor the match to the beginning of a line.
6475 as the first character following a C<"|"> indicating alternation.
6479 as the first character in a parenthesized grouping like
6486 as the first character following a quantifier
6493 The text of the message above is duplicated below to allow splain (and
6494 'use diagnostics') to work. Since one is deprecated, and one not, khw
6495 thinks they can't be combined as one message.
6497 =item Unescaped left brace in regex is deprecated here (and will be fatal in Perl 5.32), passed through in regex; marked by S<<-- HERE> in m/%s/
6499 (D deprecated, regexp) The simple rule to remember, if you want to
6500 match a literal C<"{"> character (U+007B C<LEFT CURLY BRACKET>) in a
6501 regular expression pattern, is to escape each literal instance of it in
6502 some way. Generally easiest is to precede it with a backslash, like
6503 C<"\{"> or enclose it in square brackets (C<"[{]">). If the pattern
6504 delimiters are also braces, any matching right brace (C<"}">) should
6505 also be escaped to avoid confusing the parser, for example,
6509 Forcing literal C<"{"> characters to be escaped will enable the Perl
6510 language to be extended in various ways in future releases. To avoid
6511 needlessly breaking existing code, the restriction is is not enforced in
6512 contexts where there are unlikely to ever be extensions that could
6513 conflict with the use there of C<"{"> as a literal. Those that are
6514 not potentially ambiguous do not warn; those that are do raise a
6515 non-deprecation warning.
6517 In this release of Perl, some literal uses of C<"{"> are fatal, and some
6518 still just deprecated. This is because of an oversight: some uses of a
6519 literal C<"{"> that should have raised a deprecation warning starting in
6520 v5.20 did not warn until v5.26. By making the already-warned uses fatal
6521 now, some of the planned extensions can be made to the language sooner.
6522 The cases which are still allowed will be fatal in Perl 5.32.
6524 The contexts where no warnings or errors are raised are:
6530 as the first character in a pattern, or following C<"^"> indicating to
6531 anchor the match to the beginning of a line.
6535 as the first character following a C<"|"> indicating alternation.
6539 as the first character in a parenthesized grouping like
6546 as the first character following a quantifier
6553 The text of the message above is duplicated below to allow splain (and
6554 'use diagnostics') to work. Since one is fatal, and one not, they can't
6555 be combined as one message. Perhaps perldiag could be enhanced to
6558 =item Unescaped left brace in regex is illegal here in regex;
6559 marked by S<<-- HERE> in m/%s/
6561 (F) The simple rule to remember, if you want to
6562 match a literal C<"{"> character (U+007B C<LEFT CURLY BRACKET>) in a
6563 regular expression pattern, is to escape each literal instance of it in
6564 some way. Generally easiest is to precede it with a backslash, like
6565 C<"\{"> or enclose it in square brackets (C<"[{]">). If the pattern
6566 delimiters are also braces, any matching right brace (C<"}">) should
6567 also be escaped to avoid confusing the parser, for example,
6571 Forcing literal C<"{"> characters to be escaped will enable the Perl
6572 language to be extended in various ways in future releases. To avoid
6573 needlessly breaking existing code, the restriction is is not enforced in
6574 contexts where there are unlikely to ever be extensions that could
6575 conflict with the use there of C<"{"> as a literal. Those that are
6576 not potentially ambiguous do not warn; those that are do raise a
6577 non-deprecation warning.
6579 In this release of Perl, some literal uses of C<"{"> are fatal, and some
6580 still just deprecated. This is because of an oversight: some uses of a
6581 literal C<"{"> that should have raised a deprecation warning starting in
6582 v5.20 did not warn until v5.26. By making the already-warned uses fatal
6583 now, some of the planned extensions can be made to the language sooner.
6584 The cases which are still allowed will be fatal in Perl 5.32.
6586 The contexts where no warnings or errors are raised are:
6592 as the first character in a pattern, or following C<"^"> indicating to
6593 anchor the match to the beginning of a line.
6597 as the first character following a C<"|"> indicating alternation.
6601 as the first character in a parenthesized grouping like
6608 as the first character following a quantifier
6614 =item Unescaped literal '%c' in regex; marked by <-- HERE in m/%s/
6616 (W regexp) (only under C<S<use re 'strict'>>)
6618 Within the scope of C<S<use re 'strict'>> in a regular expression
6619 pattern, you included an unescaped C<}> or C<]> which was interpreted
6620 literally. These two characters are sometimes metacharacters, and
6621 sometimes literals, depending on what precedes them in the
6622 pattern. This is unlike the similar C<)> which is always a
6623 metacharacter unless escaped.
6625 This action at a distance, perhaps a large distance, can lead to Perl
6626 silently misinterpreting what you meant, so when you specify that you
6627 want extra checking by C<S<use re 'strict'>>, this warning is generated.
6628 If you meant the character as a literal, simply confirm that to Perl by
6629 preceding the character with a backslash, or make it into a bracketed
6630 character class (like C<[}]>). If you meant it as closing a
6631 corresponding C<[> or C<{>, you'll need to look back through the pattern
6632 to find out why that isn't happening.
6634 =item unexec of %s into %s failed!
6636 (F) The unexec() routine failed for some reason. See your local FSF
6637 representative, who probably put it there in the first place.
6639 =item Unexpected binary operator '%c' with no preceding operand in regex;
6640 marked by S<<-- HERE> in m/%s/
6642 (F) You had something like this:
6646 where the C<"|"> is a binary operator with an operand on the right, but
6647 no operand on the left.
6649 =item Unexpected character in regex; marked by S<<-- HERE> in m/%s/
6651 (F) You had something like this:
6655 Within C<(?[ ])>, no literal characters are allowed unless they are
6656 within an inner pair of square brackets, like
6660 Another possibility is that you forgot a backslash. Perl isn't smart
6661 enough to figure out what you really meant.
6663 =item Unexpected constant lvalue entersub entry via type/targ %d:%d
6665 (P) When compiling a subroutine call in lvalue context, Perl failed an
6666 internal consistency check. It encountered a malformed op tree.
6668 =item Unexpected exit %u
6670 (S) exit() was called or the script otherwise finished gracefully when
6671 C<PERL_EXIT_WARN> was set in C<PL_exit_flags>.
6673 =item Unexpected exit failure %d
6675 (S) An uncaught die() was called when C<PERL_EXIT_WARN> was set in
6678 =item Unexpected ')' in regex; marked by S<<-- HERE> in m/%s/
6680 (F) You had something like this:
6682 (?[ ( \p{Digit} + ) ])
6684 The C<")"> is out-of-place. Something apparently was supposed to
6685 be combined with the digits, or the C<"+"> shouldn't be there, or
6686 something like that. Perl can't figure out what was intended.
6688 =item Unexpected ']' with no following ')' in (?[... in regex; marked by
6691 (F) While parsing an extended character class a ']' character was
6692 encountered at a point in the definition where the only legal use of
6693 ']' is to close the character class definition as part of a '])', you
6694 may have forgotten the close paren, or otherwise confused the parser.
6696 =item Unexpected '(' with no preceding operator in regex; marked by
6697 S<<-- HERE> in m/%s/
6699 (F) You had something like this:
6701 (?[ \p{Digit} ( \p{Lao} + \p{Thai} ) ])
6703 There should be an operator before the C<"(">, as there's
6704 no indication as to how the digits are to be combined
6705 with the characters in the Lao and Thai scripts.
6707 =item Unicode non-character U+%X is not recommended for open interchange
6709 (S nonchar) Certain codepoints, such as U+FFFE and U+FFFF, are
6710 defined by the Unicode standard to be non-characters. Those
6711 are legal codepoints, but are reserved for internal use; so,
6712 applications shouldn't attempt to exchange them. An application
6713 may not be expecting any of these characters at all, and receiving
6714 them may lead to bugs. If you know what you are doing you can
6715 turn off this warning by C<no warnings 'nonchar';>.
6717 This is not really a "severe" error, but it is supposed to be
6718 raised by default even if warnings are not enabled, and currently
6719 the only way to do that in Perl is to mark it as serious.
6721 =item Unicode property wildcard not terminated
6723 (F) A Unicode property wildcard looks like a delimited regular
6724 expression pattern (all within the braces of the enclosing C<\p{...}>.
6725 The closing delimtter to match the opening one was not found. If the
6726 opening one is escaped by preceding it with a backslash, the closing one
6727 must also be so escaped.
6729 =item Unicode surrogate U+%X is illegal in UTF-8
6731 (S surrogate) You had a UTF-16 surrogate in a context where they are
6732 not considered acceptable. These code points, between U+D800 and
6733 U+DFFF (inclusive), are used by Unicode only for UTF-16. However, Perl
6734 internally allows all unsigned integer code points (up to the size limit
6735 available on your platform), including surrogates. But these can cause
6736 problems when being input or output, which is likely where this message
6737 came from. If you really really know what you are doing you can turn
6738 off this warning by C<no warnings 'surrogate';>.
6740 =item Unknown charname '%s'
6742 (F) The name you used inside C<\N{}> is unknown to Perl. Check the
6743 spelling. You can say C<use charnames ":loose"> to not have to be
6744 so precise about spaces, hyphens, and capitalization on standard Unicode
6745 names. (Any custom aliases that have been created must be specified
6746 exactly, regardless of whether C<:loose> is used or not.) This error may
6747 also happen if the C<\N{}> is not in the scope of the corresponding
6748 C<S<use charnames>>.
6750 =item Unknown '(*...)' construct '%s' in regex; marked by <-- HERE in m/%s/
6752 (F) The C<(*> was followed by something that the regular expression
6753 compiler does not recognize. Check your spelling.
6757 (P) Perl was about to print an error message in C<$@>, but the C<$@> variable
6758 did not exist, even after an attempt to create it.
6760 =item Unknown locale category %d; can't set it to %s
6762 (W locale) You used a locale category that perl doesn't recognize, so it
6763 cannot carry out your request. Check that you are using a valid
6764 category. If so, see L<perllocale/Multi-threaded> for advice on
6765 reporting this as a bug, and for modifying perl locally to accommodate
6768 =item Unknown open() mode '%s'
6770 (F) The second argument of 3-argument open() is not among the list
6771 of valid modes: C<< < >>, C<< > >>, C<<< >> >>>, C<< +< >>,
6772 C<< +> >>, C<<< +>> >>>, C<-|>, C<|->, C<< <& >>, C<< >& >>.
6774 =item Unknown PerlIO layer "%s"
6776 (W layer) An attempt was made to push an unknown layer onto the Perl I/O
6777 system. (Layers take care of transforming data between external and
6778 internal representations.) Note that some layers, such as C<mmap>,
6779 are not supported in all environments. If your program didn't
6780 explicitly request the failing operation, it may be the result of the
6781 value of the environment variable PERLIO.
6783 =item Unknown process %x sent message to prime_env_iter: %s
6785 (P) An error peculiar to VMS. Perl was reading values for %ENV before
6786 iterating over it, and someone else stuck a message in the stream of
6787 data Perl expected. Someone's very confused, or perhaps trying to
6788 subvert Perl's population of %ENV for nefarious purposes.
6790 =item Unknown regexp modifier "/%s"
6792 (F) Alphanumerics immediately following the closing delimiter
6793 of a regular expression pattern are interpreted by Perl as modifier
6794 flags for the regex. One of the ones you specified is invalid. One way
6795 this can happen is if you didn't put in white space between the end of
6796 the regex and a following alphanumeric operator:
6798 if ($a =~ /foo/and $bar == 3) { ... }
6800 The C<"a"> is a valid modifier flag, but the C<"n"> is not, and raises
6801 this error. Likely what was meant instead was:
6803 if ($a =~ /foo/ and $bar == 3) { ... }
6805 =item Unknown "re" subpragma '%s' (known ones are: %s)
6807 (W) You tried to use an unknown subpragma of the "re" pragma.
6809 =item Unknown switch condition (?(...)) in regex; marked by S<<-- HERE> in
6812 (F) The condition part of a (?(condition)if-clause|else-clause) construct
6813 is not known. The condition must be one of the following:
6815 (1) (2) ... true if 1st, 2nd, etc., capture matched
6816 (<NAME>) ('NAME') true if named capture matched
6817 (?=...) (?<=...) true if subpattern matches
6818 (*pla:...) (*plb:...) true if subpattern matches; also
6819 (*positive_lookahead:...)
6820 (*positive_lookbehind:...)
6821 (*nla:...) (*nlb:...) true if subpattern fails to match; also
6822 (*negative_lookahead:...)
6823 (*negative_lookbehind:...)
6824 (?{ CODE }) true if code returns a true value
6825 (R) true if evaluating inside recursion
6826 (R1) (R2) ... true if directly inside capture group 1, 2,
6828 (R&NAME) true if directly inside named capture
6829 (DEFINE) always false; for defining named subpatterns
6831 The S<<-- HERE> shows whereabouts in the regular expression the problem was
6832 discovered. See L<perlre>.
6834 =item Unknown Unicode option letter '%c'
6836 (F) You specified an unknown Unicode option. See L<perlrun> documentation
6837 of the C<-C> switch for the list of known options.
6839 =item Unknown Unicode option value %d
6841 (F) You specified an unknown Unicode option. See L<perlrun> documentation
6842 of the C<-C> switch for the list of known options.
6844 =item Unknown verb pattern '%s' in regex; marked by S<<-- HERE> in m/%s/
6846 (F) You either made a typo or have incorrectly put a C<*> quantifier
6847 after an open brace in your pattern. Check the pattern and review
6848 L<perlre> for details on legal verb patterns.
6850 =item Unknown warnings category '%s'
6852 (F) An error issued by the C<warnings> pragma. You specified a warnings
6853 category that is unknown to perl at this point.
6855 Note that if you want to enable a warnings category registered by a
6856 module (e.g. C<use warnings 'File::Find'>), you must have loaded this
6859 =item Unmatched [ in regex; marked by S<<-- HERE> in m/%s/
6861 (F) The brackets around a character class must match. If you wish to
6862 include a closing bracket in a character class, backslash it or put it
6863 first. The S<<-- HERE> shows whereabouts in the regular expression the
6864 problem was discovered. See L<perlre>.
6866 =item Unmatched ( in regex; marked by S<<-- HERE> in m/%s/
6868 =item Unmatched ) in regex; marked by S<<-- HERE> in m/%s/
6870 (F) Unbackslashed parentheses must always be balanced in regular
6871 expressions. If you're a vi user, the % key is valuable for finding
6872 the matching parenthesis. The S<<-- HERE> shows whereabouts in the
6873 regular expression the problem was discovered. See L<perlre>.
6875 =item Unmatched right %s bracket
6877 (F) The lexer counted more closing curly or square brackets than opening
6878 ones, so you're probably missing a matching opening bracket. As a
6879 general rule, you'll find the missing one (so to speak) near the place
6880 you were last editing.
6882 =item Unquoted string "%s" may clash with future reserved word
6884 (W reserved) You used a bareword that might someday be claimed as a
6885 reserved word. It's best to put such a word in quotes, or capitalize it
6886 somehow, or insert an underbar into it. You might also declare it as a
6889 =item Unrecognized character %s; marked by S<<-- HERE> after %s near column
6892 (F) The Perl parser has no idea what to do with the specified character
6893 in your Perl script (or eval) near the specified column. Perhaps you
6894 tried to run a compressed script, a binary program, or a directory as
6897 =item Unrecognized escape \%c in character class in regex; marked by
6898 S<<-- HERE> in m/%s/
6900 (F) You used a backslash-character combination which is not
6901 recognized by Perl inside character classes. This is a fatal
6902 error when the character class is used within C<(?[ ])>.
6904 =item Unrecognized escape \%c in character class passed through in regex;
6905 marked by S<<-- HERE> in m/%s/
6907 (W regexp) You used a backslash-character combination which is not
6908 recognized by Perl inside character classes. The character was
6909 understood literally, but this may change in a future version of Perl.
6910 The S<<-- HERE> shows whereabouts in the regular expression the
6911 escape was discovered.
6913 =item Unrecognized escape \%c passed through
6915 (W misc) You used a backslash-character combination which is not
6916 recognized by Perl. The character was understood literally, but this may
6917 change in a future version of Perl.
6919 =item Unrecognized escape \%s passed through in regex; marked by
6920 S<<-- HERE> in m/%s/
6922 (W regexp) You used a backslash-character combination which is not
6923 recognized by Perl. The character(s) were understood literally, but
6924 this may change in a future version of Perl. The S<<-- HERE> shows
6925 whereabouts in the regular expression the escape was discovered.
6927 =item Unrecognized signal name "%s"
6929 (F) You specified a signal name to the kill() function that was not
6930 recognized. Say C<kill -l> in your shell to see the valid signal names
6933 =item Unrecognized switch: -%s (-h will show valid options)
6935 (F) You specified an illegal option to Perl. Don't do that. (If you
6936 think you didn't do that, check the #! line to see if it's supplying the
6937 bad switch on your behalf.)
6939 =item Unsuccessful %s on filename containing newline
6941 (W newline) A file operation was attempted on a filename, and that
6942 operation failed, PROBABLY because the filename contained a newline,
6943 PROBABLY because you forgot to chomp() it off. See L<perlfunc/chomp>.
6945 =item Unsupported directory function "%s" called
6947 (F) Your machine doesn't support opendir() and readdir().
6949 =item Unsupported function %s
6951 (F) This machine doesn't implement the indicated function, apparently.
6952 At least, Configure doesn't think so.
6954 =item Unsupported function fork
6956 (F) Your version of executable does not support forking.
6958 Note that under some systems, like OS/2, there may be different flavors
6959 of Perl executables, some of which may support fork, some not. Try
6960 changing the name you call Perl by to C<perl_>, C<perl__>, and so on.
6962 =item Unsupported script encoding %s
6964 (F) Your program file begins with a Unicode Byte Order Mark (BOM) which
6965 declares it to be in a Unicode encoding that Perl cannot read.
6967 =item Unsupported socket function "%s" called
6969 (F) Your machine doesn't support the Berkeley socket mechanism, or at
6970 least that's what Configure thought.
6972 =item Unterminated '(*...' argument in regex; marked by <-- HERE in m/%s/
6974 (F) You used a pattern of the form C<(*...:...)> but did not terminate
6975 the pattern with a C<)>. Fix the pattern and retry.
6977 =item Unterminated attribute list
6979 (F) The lexer found something other than a simple identifier at the
6980 start of an attribute, and it wasn't a semicolon or the start of a
6981 block. Perhaps you terminated the parameter list of the previous
6982 attribute too soon. See L<attributes>.
6984 =item Unterminated attribute parameter in attribute list
6986 (F) The lexer saw an opening (left) parenthesis character while parsing
6987 an attribute list, but the matching closing (right) parenthesis
6988 character was not found. You may need to add (or remove) a backslash
6989 character to get your parentheses to balance. See L<attributes>.
6991 =item Unterminated compressed integer
6993 (F) An argument to unpack("w",...) was incompatible with the BER
6994 compressed integer format and could not be converted to an integer.
6995 See L<perlfunc/pack>.
6997 =item Unterminated '(*...' construct in regex; marked by <-- HERE in m/%s/
6999 (F) You used a pattern of the form C<(*...)> but did not terminate
7000 the pattern with a C<)>. Fix the pattern and retry.
7002 =item Unterminated delimiter for here document
7004 (F) This message occurs when a here document label has an initial
7005 quotation mark but the final quotation mark is missing. Perhaps
7014 =item Unterminated \g... pattern in regex; marked by S<<-- HERE> in m/%s/
7016 =item Unterminated \g{...} pattern in regex; marked by S<<-- HERE> in m/%s/
7018 (F) In a regular expression, you had a C<\g> that wasn't followed by a
7019 proper group reference. In the case of C<\g{>, the closing brace is
7020 missing; otherwise the C<\g> must be followed by an integer. Fix the
7023 =item Unterminated <> operator
7025 (F) The lexer saw a left angle bracket in a place where it was expecting
7026 a term, so it's looking for the corresponding right angle bracket, and
7027 not finding it. Chances are you left some needed parentheses out
7028 earlier in the line, and you really meant a "less than".
7030 =item Unterminated verb pattern argument in regex; marked by S<<-- HERE> in
7033 (F) You used a pattern of the form C<(*VERB:ARG)> but did not terminate
7034 the pattern with a C<)>. Fix the pattern and retry.
7036 =item Unterminated verb pattern in regex; marked by S<<-- HERE> in m/%s/
7038 (F) You used a pattern of the form C<(*VERB)> but did not terminate
7039 the pattern with a C<)>. Fix the pattern and retry.
7041 =item untie attempted while %d inner references still exist
7043 (W untie) A copy of the object returned from C<tie> (or C<tied>) was
7044 still valid when C<untie> was called.
7046 =item Usage: POSIX::%s(%s)
7048 (F) You called a POSIX function with incorrect arguments.
7049 See L<POSIX/FUNCTIONS> for more information.
7051 =item Usage: Win32::%s(%s)
7053 (F) You called a Win32 function with incorrect arguments.
7054 See L<Win32> for more information.
7056 =item $[ used in %s (did you mean $] ?)
7058 (W syntax) You used C<$[> in a comparison, such as:
7064 You probably meant to use C<$]> instead. C<$[> is the base for indexing
7065 arrays. C<$]> is the Perl version number in decimal.
7067 =item Use "%s" instead of "%s"
7069 (F) The second listed construct is no longer legal. Use the first one
7072 =item Useless assignment to a temporary
7074 (W misc) You assigned to an lvalue subroutine, but what
7075 the subroutine returned was a temporary scalar about to
7076 be discarded, so the assignment had no effect.
7078 =item Useless (?-%s) - don't use /%s modifier in regex; marked by
7079 S<<-- HERE> in m/%s/
7081 (W regexp) You have used an internal modifier such as (?-o) that has no
7082 meaning unless removed from the entire regexp:
7084 if ($string =~ /(?-o)$pattern/o) { ... }
7088 if ($string =~ /$pattern/) { ... }
7090 The S<<-- HERE> shows whereabouts in the regular expression the problem was
7091 discovered. See L<perlre>.
7093 =item Useless localization of %s
7095 (W syntax) The localization of lvalues such as C<local($x=10)> is legal,
7096 but in fact the local() currently has no effect. This may change at
7097 some point in the future, but in the meantime such code is discouraged.
7099 =item Useless (?%s) - use /%s modifier in regex; marked by S<<-- HERE> in
7102 (W regexp) You have used an internal modifier such as (?o) that has no
7103 meaning unless applied to the entire regexp:
7105 if ($string =~ /(?o)$pattern/) { ... }
7109 if ($string =~ /$pattern/o) { ... }
7111 The S<<-- HERE> shows whereabouts in the regular expression the problem was
7112 discovered. See L<perlre>.
7114 =item Useless use of attribute "const"
7116 (W misc) The C<const> attribute has no effect except
7117 on anonymous closure prototypes. You applied it to
7118 a subroutine via L<attributes.pm|attributes>. This is only useful
7119 inside an attribute handler for an anonymous subroutine.
7121 =item Useless use of /d modifier in transliteration operator
7123 (W misc) You have used the /d modifier where the searchlist has the
7124 same length as the replacelist. See L<perlop> for more information
7125 about the /d modifier.
7127 =item Useless use of \E
7129 (W misc) You have a \E in a double-quotish string without a C<\U>,
7130 C<\L> or C<\Q> preceding it.
7132 =item Useless use of greediness modifier '%c' in regex; marked by S<<-- HERE> in m/%s/
7134 (W regexp) You specified something like these:
7139 The C<"?"> and C<"+"> don't have any effect, as they modify whether to
7140 match more or fewer when there is a choice, and by specifying to match
7141 exactly a given numer, there is no room left for a choice.
7143 =item Useless use of %s in void context
7145 (W void) You did something without a side effect in a context that does
7146 nothing with the return value, such as a statement that doesn't return a
7147 value from a block, or the left side of a scalar comma operator. Very
7148 often this points not to stupidity on your part, but a failure of Perl
7149 to parse your program the way you thought it would. For example, you'd
7150 get this if you mixed up your C precedence with Python precedence and
7155 when you meant to say
7157 ($one, $two) = (1, 2);
7159 Another common error is to use ordinary parentheses to construct a list
7160 reference when you should be using square or curly brackets, for
7165 when you should have said
7169 The square brackets explicitly turn a list value into a scalar value,
7170 while parentheses do not. So when a parenthesized list is evaluated in
7171 a scalar context, the comma is treated like C's comma operator, which
7172 throws away the left argument, which is not what you want. See
7173 L<perlref> for more on this.
7175 This warning will not be issued for numerical constants equal to 0 or 1
7176 since they are often used in statements like
7178 1 while sub_with_side_effects();
7180 String constants that would normally evaluate to 0 or 1 are warned
7183 =item Useless use of (?-p) in regex; marked by S<<-- HERE> in m/%s/
7185 (W regexp) The C<p> modifier cannot be turned off once set. Trying to do
7188 =item Useless use of "re" pragma
7190 (W) You did C<use re;> without any arguments. That isn't very useful.
7192 =item Useless use of sort in scalar context
7194 (W void) You used sort in scalar context, as in :
7198 This is not very useful, and perl currently optimizes this away.
7200 =item Useless use of %s with no values
7202 (W syntax) You used the push() or unshift() function with no arguments
7203 apart from the array, like C<push(@x)> or C<unshift(@foo)>. That won't
7204 usually have any effect on the array, so is completely useless. It's
7205 possible in principle that push(@tied_array) could have some effect
7206 if the array is tied to a class which implements a PUSH method. If so,
7207 you can write it as C<push(@tied_array,())> to avoid this warning.
7209 =item "use" not allowed in expression
7211 (F) The "use" keyword is recognized and executed at compile time, and
7212 returns no useful value. See L<perlmod>.
7214 =item Use of bare << to mean <<"" is forbidden
7216 (F) You are now required to use the explicitly quoted form if you wish
7217 to use an empty line as the terminator of the here-document.
7219 Use of a bare terminator was deprecated in Perl 5.000, and is a fatal
7220 error as of Perl 5.28.
7222 =item Use of /c modifier is meaningless in s///
7224 (W regexp) You used the /c modifier in a substitution. The /c
7225 modifier is not presently meaningful in substitutions.
7227 =item Use of /c modifier is meaningless without /g
7229 (W regexp) You used the /c modifier with a regex operand, but didn't
7230 use the /g modifier. Currently, /c is meaningful only when /g is
7231 used. (This may change in the future.)
7233 =item Use of code point 0x%s is not allowed; the permissible max is 0x%x
7235 =item Use of code point 0x%s is not allowed; the permissible max is 0x%x
7236 in regex; marked by <-- HERE in m/%s/
7238 (F) You used a code point that is not allowed, because it is too large.
7239 Unicode only allows code points up to 0x10FFFF, but Perl allows much
7240 larger ones. Earlier versions of Perl allowed code points above IV_MAX
7241 (0x7FFFFFF on 32-bit platforms, 0x7FFFFFFFFFFFFFFF on 64-bit platforms),
7242 however, this could possibly break the perl interpreter in some constructs,
7243 including causing it to hang in a few cases.
7245 If your code is to run on various platforms, keep in mind that the upper
7246 limit depends on the platform. It is much larger on 64-bit word sizes
7249 The use of out of range code points was deprecated in Perl 5.24, and
7250 became a fatal error in Perl 5.28.
7252 =item Use of each() on hash after insertion without resetting hash iterator results in undefined behavior
7254 (S internal) The behavior of C<each()> after insertion is undefined;
7255 it may skip items, or visit items more than once. Consider using
7256 C<keys()> instead of C<each()>.
7258 =item Use of := for an empty attribute list is not allowed
7260 (F) The construction C<my $x := 42> used to parse as equivalent to
7261 C<my $x : = 42> (applying an empty attribute list to C<$x>).
7262 This construct was deprecated in 5.12.0, and has now been made a syntax
7263 error, so C<:=> can be reclaimed as a new operator in the future.
7265 If you need an empty attribute list, for example in a code generator, add
7266 a space before the C<=>.
7268 =item Use of %s for non-UTF-8 locale is wrong. Assuming a UTF-8 locale
7270 (W locale) You are matching a regular expression using locale rules,
7271 and the specified construct was encountered. This construct is only
7272 valid for UTF-8 locales, which the current locale isn't. This doesn't
7273 make sense. Perl will continue, assuming a Unicode (UTF-8) locale, but
7274 the results are likely to be wrong.
7276 =item Use of freed value in iteration
7278 (F) Perhaps you modified the iterated array within the loop?
7279 This error is typically caused by code like the following:
7282 @a = () for (1,2,@a);
7284 You are not supposed to modify arrays while they are being iterated over.
7285 For speed and efficiency reasons, Perl internally does not do full
7286 reference-counting of iterated items, hence deleting such an item in the
7287 middle of an iteration causes Perl to see a freed value.
7289 =item Use of /g modifier is meaningless in split
7291 (W regexp) You used the /g modifier on the pattern for a C<split>
7292 operator. Since C<split> always tries to match the pattern
7293 repeatedly, the C</g> has no effect.
7295 =item Use of "goto" to jump into a construct is deprecated
7297 (D deprecated) Using C<goto> to jump from an outer scope into an inner
7298 scope is deprecated and should be avoided.
7300 This was deprecated in Perl 5.12.
7302 =item Use of '%s' in \p{} or \P{} is deprecated because: %s
7304 (D deprecated) Certain properties are deprecated by Unicode, and may
7305 eventually be removed from the Standard, at which time Perl will follow
7306 along. In the meantime, this message is raised to notify you.
7308 =item Use of inherited AUTOLOAD for non-method %s::%s() is no longer allowed
7310 (F) As an accidental feature, C<AUTOLOAD> subroutines were looked up as
7311 methods (using the C<@ISA> hierarchy), even when the subroutines to be
7312 autoloaded were called as plain functions (e.g. C<Foo::bar()>), not as
7313 methods (e.g. C<< Foo->bar() >> or C<< $obj->bar() >>).
7315 This was deprecated in Perl 5.004, and was made fatal in Perl 5.28.
7317 =item Use of %s in printf format not supported
7319 (F) You attempted to use a feature of printf that is accessible from
7320 only C. This usually means there's a better way to do it in Perl.
7322 =item Use of -l on filehandle%s
7324 (W io) A filehandle represents an opened file, and when you opened the file
7325 it already went past any symlink you are presumably trying to look for.
7326 The operation returned C<undef>. Use a filename instead.
7328 =item Use of reference "%s" as array index
7330 (W misc) You tried to use a reference as an array index; this probably
7331 isn't what you mean, because references in numerical context tend
7332 to be huge numbers, and so usually indicates programmer error.
7334 If you really do mean it, explicitly numify your reference, like so:
7335 C<$array[0+$ref]>. This warning is not given for overloaded objects,
7336 however, because you can overload the numification and stringification
7337 operators and then you presumably know what you are doing.
7339 =item Use of strings with code points over 0xFF as arguments to %s
7340 operator is not allowed
7342 (F) You tried to use one of the string bitwise operators (C<&> or C<|> or C<^> or
7343 C<~>) on a string containing a code point over 0xFF. The string bitwise
7344 operators treat their operands as strings of bytes, and values beyond
7345 0xFF are nonsensical in this context.
7347 Certain instances became fatal in Perl 5.28; others in perl 5.32.
7349 =item Use of strings with code points over 0xFF as arguments to vec is forbidden
7351 (F) You tried to use L<C<vec>|perlfunc/vec EXPR,OFFSET,BITS>
7352 on a string containing a code point over 0xFF, which is nonsensical here.
7354 This became fatal in Perl 5.32.
7356 =item Use of tainted arguments in %s is deprecated
7358 (W taint, deprecated) You have supplied C<system()> or C<exec()> with multiple
7359 arguments and at least one of them is tainted. This used to be allowed
7360 but will become a fatal error in a future version of perl. Untaint your
7361 arguments. See L<perlsec>.
7363 =item Use of unassigned code point or non-standalone grapheme for a
7364 delimiter is not allowed
7367 A grapheme is what appears to a native-speaker of a language to be a
7368 character. In Unicode (and hence Perl) a grapheme may actually be
7369 several adjacent characters that together form a complete grapheme. For
7370 example, there can be a base character, like "R" and an accent, like a
7371 circumflex "^", that appear when displayed to be a single character with
7372 the circumflex hovering over the "R". Perl currently allows things like
7373 that circumflex to be delimiters of strings, patterns, I<etc>. When
7374 displayed, the circumflex would look like it belongs to the character
7375 just to the left of it. In order to move the language to be able to
7376 accept graphemes as delimiters, we cannot allow the use of
7377 delimiters which aren't graphemes by themselves. Also, a delimiter must
7378 already be assigned (or known to be never going to be assigned) to try
7379 to future-proof code, for otherwise code that works today would fail to
7380 compile if the currently unassigned delimiter ends up being something
7381 that isn't a stand-alone grapheme. Because Unicode is never going to
7383 L<non-character code points|perlunicode/Noncharacter code points>, nor
7384 L<code points that are above the legal Unicode maximum|
7385 perlunicode/Beyond Unicode code points>, those can be delimiters, and
7388 =item Use of uninitialized value%s
7390 (W uninitialized) An undefined value was used as if it were already
7391 defined. It was interpreted as a "" or a 0, but maybe it was a mistake.
7392 To suppress this warning assign a defined value to your variables.
7394 To help you figure out what was undefined, perl will try to tell you
7395 the name of the variable (if any) that was undefined. In some cases
7396 it cannot do this, so it also tells you what operation you used the
7397 undefined value in. Note, however, that perl optimizes your program
7398 and the operation displayed in the warning may not necessarily appear
7399 literally in your program. For example, C<"that $foo"> is usually
7400 optimized into C<"that " . $foo>, and the warning will refer to the
7401 C<concatenation (.)> operator, even though there is no C<.> in
7404 =item "use re 'strict'" is experimental
7406 (S experimental::re_strict) The things that are different when a regular
7407 expression pattern is compiled under C<'strict'> are subject to change
7408 in future Perl releases in incompatible ways. This means that a pattern
7409 that compiles today may not in a future Perl release. This warning is
7410 to alert you to that risk.
7412 =item Use \x{...} for more than two hex characters in regex; marked by
7413 S<<-- HERE> in m/%s/
7415 (F) In a regular expression, you said something like
7419 Perl isn't sure if you meant this
7423 or if you meant this
7425 (?[ [ \x{BE} E F ] ])
7427 You need to add either braces or blanks to disambiguate.
7429 =item Using just the first character returned by \N{} in character class in
7430 regex; marked by S<<-- HERE> in m/%s/
7432 (W regexp) Named Unicode character escapes C<(\N{...})> may return
7433 a multi-character sequence. Even though a character class is
7434 supposed to match just one character of input, perl will match
7435 the whole thing correctly, except when the class is inverted
7436 (C<[^...]>), or the escape is the beginning or final end point of
7437 a range. For these, what should happen isn't clear at all. In
7438 these circumstances, Perl discards all but the first character
7439 of the returned sequence, which is not likely what you want.
7441 =item Using /u for '%s' instead of /%s in regex; marked by S<<-- HERE> in m/%s/
7443 (W regexp) You used a Unicode boundary (C<\b{...}> or C<\B{...}>) in a
7444 portion of a regular expression where the character set modifiers C</a>
7445 or C</aa> are in effect. These two modifiers indicate an ASCII
7446 interpretation, and this doesn't make sense for a Unicode definition.
7447 The generated regular expression will compile so that the boundary uses
7448 all of Unicode. No other portion of the regular expression is affected.
7450 =item Using !~ with %s doesn't make sense
7452 (F) Using the C<!~> operator with C<s///r>, C<tr///r> or C<y///r> is
7453 currently reserved for future use, as the exact behavior has not
7454 been decided. (Simply returning the boolean opposite of the
7455 modified string is usually not particularly useful.)
7457 =item UTF-16 surrogate U+%X
7459 (S surrogate) You had a UTF-16 surrogate in a context where they are
7460 not considered acceptable. These code points, between U+D800 and
7461 U+DFFF (inclusive), are used by Unicode only for UTF-16. However, Perl
7462 internally allows all unsigned integer code points (up to the size limit
7463 available on your platform), including surrogates. But these can cause
7464 problems when being input or output, which is likely where this message
7465 came from. If you really really know what you are doing you can turn
7466 off this warning by C<no warnings 'surrogate';>.
7468 =item Value of %s can be "0"; test with defined()
7470 (W misc) In a conditional expression, you used <HANDLE>, <*> (glob),
7471 C<each()>, or C<readdir()> as a boolean value. Each of these constructs
7472 can return a value of "0"; that would make the conditional expression
7473 false, which is probably not what you intended. When using these
7474 constructs in conditional expressions, test their values with the
7475 C<defined> operator.
7477 =item Value of CLI symbol "%s" too long
7479 (W misc) A warning peculiar to VMS. Perl tried to read the value of an
7480 %ENV element from a CLI symbol table, and found a resultant string
7481 longer than 1024 characters. The return value has been truncated to
7484 =item Variable "%s" is not available
7486 (W closure) During compilation, an inner named subroutine or eval is
7487 attempting to capture an outer lexical that is not currently available.
7488 This can happen for one of two reasons. First, the outer lexical may be
7489 declared in an outer anonymous subroutine that has not yet been created.
7490 (Remember that named subs are created at compile time, while anonymous
7491 subs are created at run-time.) For example,
7493 sub { my $a; sub f { $a } }
7495 At the time that f is created, it can't capture the current value of $a,
7496 since the anonymous subroutine hasn't been created yet. Conversely,
7497 the following won't give a warning since the anonymous subroutine has by
7498 now been created and is live:
7500 sub { my $a; eval 'sub f { $a }' }->();
7502 The second situation is caused by an eval accessing a variable that has
7503 gone out of scope, for example,
7511 Here, when the '$a' in the eval is being compiled, f() is not currently
7512 being executed, so its $a is not available for capture.
7514 =item Variable "%s" is not imported%s
7516 (S misc) With "use strict" in effect, you referred to a global variable
7517 that you apparently thought was imported from another module, because
7518 something else of the same name (usually a subroutine) is exported by
7519 that module. It usually means you put the wrong funny character on the
7520 front of your variable.
7522 =item Variable length lookbehind not implemented in regex m/%s/
7524 (F) B<This message no longer should be raised as of Perl 5.30.> It is
7525 retained in this document as a convenience for people using an earlier
7528 In Perl 5.30 and earlier, lookbehind is allowed
7529 only for subexpressions whose length is fixed and
7530 known at compile time. For positive lookbehind, you can use the C<\K>
7531 regex construct as a way to get the equivalent functionality. See
7532 L<(?<=pattern) and \K in perlre|perlre/\K>.
7534 Starting in Perl 5.18, there are non-obvious Unicode rules under C</i>
7535 that can match variably, but which you might not think could. For
7536 example, the substring C<"ss"> can match the single character LATIN
7537 SMALL LETTER SHARP S. Here's a complete list of the current ones
7538 affecting ASCII characters:
7541 sequence Matches single letter under /i
7542 FF U+FB00 LATIN SMALL LIGATURE FF
7543 FFI U+FB03 LATIN SMALL LIGATURE FFI
7544 FFL U+FB04 LATIN SMALL LIGATURE FFL
7545 FI U+FB01 LATIN SMALL LIGATURE FI
7546 FL U+FB02 LATIN SMALL LIGATURE FL
7547 SS U+00DF LATIN SMALL LETTER SHARP S
7548 U+1E9E LATIN CAPITAL LETTER SHARP S
7549 ST U+FB06 LATIN SMALL LIGATURE ST
7550 U+FB05 LATIN SMALL LIGATURE LONG S T
7552 This list is subject to change, but is quite unlikely to.
7553 Each ASCII sequence can be any combination of upper- and lowercase.
7555 You can avoid this by using a bracketed character class in the
7556 lookbehind assertion, like
7561 This fools Perl into not matching the ligatures.
7563 Another option for Perls starting with 5.16, if you only care about
7564 ASCII matches, is to add the C</aa> modifier to the regex. This will
7565 exclude all these non-obvious matches, thus getting rid of this message.
7568 use if $] ge 5.016, re => '/aa';
7570 to apply C</aa> to all regular expressions compiled within its scope.
7573 =item "%s" variable %s masks earlier declaration in same %s
7575 (W shadow) A "my", "our" or "state" variable has been redeclared in the
7576 current scope or statement, effectively eliminating all access to the
7577 previous instance. This is almost always a typographical error. Note
7578 that the earlier variable will still exist until the end of the scope
7579 or until all closure references to it are destroyed.
7581 =item Variable syntax
7583 (A) You've accidentally run your script through B<csh> instead
7584 of Perl. Check the #! line, or manually feed your script into
7587 =item Variable "%s" will not stay shared
7589 (W closure) An inner (nested) I<named> subroutine is referencing a
7590 lexical variable defined in an outer named subroutine.
7592 When the inner subroutine is called, it will see the value of
7593 the outer subroutine's variable as it was before and during the *first*
7594 call to the outer subroutine; in this case, after the first call to the
7595 outer subroutine is complete, the inner and outer subroutines will no
7596 longer share a common value for the variable. In other words, the
7597 variable will no longer be shared.
7599 This problem can usually be solved by making the inner subroutine
7600 anonymous, using the C<sub {}> syntax. When inner anonymous subs that
7601 reference variables in outer subroutines are created, they
7602 are automatically rebound to the current values of such variables.
7604 =item vector argument not supported with alpha versions
7606 (S printf) The %vd (s)printf format does not support version objects
7609 =item Verb pattern '%s' has a mandatory argument in regex; marked by
7610 S<<-- HERE> in m/%s/
7612 (F) You used a verb pattern that requires an argument. Supply an
7613 argument or check that you are using the right verb.
7615 =item Verb pattern '%s' may not have an argument in regex; marked by
7616 S<<-- HERE> in m/%s/
7618 (F) You used a verb pattern that is not allowed an argument. Remove the
7619 argument or check that you are using the right verb.
7621 =item Version control conflict marker
7623 (F) The parser found a line starting with C<E<lt><<<<<<>,
7624 C<E<gt>E<gt>E<gt>E<gt>E<gt>E<gt>E<gt>>, or C<=======>. These may be left by a
7625 version control system to mark conflicts after a failed merge operation.
7627 =item Version number must be a constant number
7629 (P) The attempt to translate a C<use Module n.n LIST> statement into
7630 its equivalent C<BEGIN> block found an internal inconsistency with
7633 =item Version string '%s' contains invalid data; ignoring: '%s'
7635 (W misc) The version string contains invalid characters at the end, which
7638 =item Warning: something's wrong
7640 (W) You passed warn() an empty string (the equivalent of C<warn "">) or
7641 you called it with no args and C<$@> was empty.
7643 =item Warning: unable to close filehandle %s properly
7645 (S) The implicit close() done by an open() got an error indication on
7646 the close(). This usually indicates your file system ran out of disk
7649 =item Warning: unable to close filehandle properly: %s
7651 =item Warning: unable to close filehandle %s properly: %s
7653 (S io) There were errors during the implicit close() done on a filehandle
7654 when its reference count reached zero while it was still open, e.g.:
7657 open my $fh, '>', $file or die "open: '$file': $!\n";
7658 print $fh $data or die "print: $!";
7659 } # implicit close here
7661 Because various errors may only be detected by close() (e.g. buffering could
7662 allow the C<print> in this example to return true even when the disk is full),
7663 it is dangerous to ignore its result. So when it happens implicitly, perl
7664 will signal errors by warning.
7666 B<Prior to version 5.22.0, perl ignored such errors>, so the common idiom shown
7667 above was liable to cause B<silent data loss>.
7669 =item Warning: Use of "%s" without parentheses is ambiguous
7671 (S ambiguous) You wrote a unary operator followed by something that
7672 looks like a binary operator that could also have been interpreted as a
7673 term or unary operator. For instance, if you know that the rand
7674 function has a default argument of 1.0, and you write
7678 you may THINK you wrote the same thing as
7682 but in actual fact, you got
7686 So put in parentheses to say what you really mean.
7688 =item when is experimental
7690 (S experimental::smartmatch) C<when> depends on smartmatch, which is
7691 experimental. Additionally, it has several special cases that may
7692 not be immediately obvious, and their behavior may change or
7693 even be removed in any future release of perl. See the explanation
7694 under L<perlsyn/Experimental Details on given and when>.
7696 =item Wide character in %s
7698 (S utf8) Perl met a wide character (ordinal >255) when it wasn't
7699 expecting one. This warning is by default on for I/O (like print).
7701 If this warning does come from I/O, the easiest
7702 way to quiet it is simply to add the C<:utf8> layer, I<e.g.>,
7703 S<C<binmode STDOUT, ':utf8'>>. Another way to turn off the warning is
7704 to add S<C<no warnings 'utf8';>> but that is often closer to
7705 cheating. In general, you are supposed to explicitly mark the
7706 filehandle with an encoding, see L<open> and L<perlfunc/binmode>.
7708 If the warning comes from other than I/O, this diagnostic probably
7709 indicates that incorrect results are being obtained. You should examine
7710 your code to determine how a wide character is getting to an operation
7711 that doesn't handle them.
7713 =item Wide character (U+%X) in %s
7715 (W locale) While in a single-byte locale (I<i.e.>, a non-UTF-8
7716 one), a multi-byte character was encountered. Perl considers this
7717 character to be the specified Unicode code point. Combining non-UTF-8
7718 locales and Unicode is dangerous. Almost certainly some characters
7719 will have two different representations. For example, in the ISO 8859-7
7720 (Greek) locale, the code point 0xC3 represents a Capital Gamma. But so
7721 also does 0x393. This will make string comparisons unreliable.
7723 You likely need to figure out how this multi-byte character got mixed up
7724 with your single-byte locale (or perhaps you thought you had a UTF-8
7725 locale, but Perl disagrees).
7727 =item Within []-length '%c' not allowed
7729 (F) The count in the (un)pack template may be replaced by C<[TEMPLATE]>
7730 only if C<TEMPLATE> always matches the same amount of packed bytes that
7731 can be determined from the template alone. This is not possible if
7732 it contains any of the codes @, /, U, u, w or a *-length. Redesign
7735 =item %s() with negative argument
7737 (S misc) Certain operations make no sense with negative arguments.
7738 Warning is given and the operation is not done.
7740 =item write() on closed filehandle %s
7742 (W closed) The filehandle you're writing to got itself closed sometime
7743 before now. Check your control flow.
7745 =item %s "\x%X" does not map to Unicode
7747 (S utf8) When reading in different encodings, Perl tries to
7748 map everything into Unicode characters. The bytes you read
7749 in are not legal in this encoding. For example
7751 utf8 "\xE4" does not map to Unicode
7753 if you try to read in the a-diaereses Latin-1 as UTF-8.
7755 =item 'X' outside of string
7757 (F) You had a (un)pack template that specified a relative position before
7758 the beginning of the string being (un)packed. See L<perlfunc/pack>.
7760 =item 'x' outside of string in unpack
7762 (F) You had a pack template that specified a relative position after
7763 the end of the string being unpacked. See L<perlfunc/pack>.
7765 =item YOU HAVEN'T DISABLED SET-ID SCRIPTS IN THE KERNEL YET!
7767 (F) And you probably never will, because you probably don't have the
7768 sources to your kernel, and your vendor probably doesn't give a rip
7769 about what you want. There is a vulnerability anywhere that you have a
7770 set-id script, and to close it you need to remove the set-id bit from
7771 the script that you're attempting to run. To actually run the script
7772 set-id, your best bet is to put a set-id C wrapper around your script.
7774 =item You need to quote "%s"
7776 (W syntax) You assigned a bareword as a signal handler name.
7777 Unfortunately, you already have a subroutine of that name declared,
7778 which means that Perl 5 will try to call the subroutine when the
7779 assignment is executed, which is probably not what you want. (If it IS
7780 what you want, put an & in front.)
7782 =item Your random numbers are not that random
7784 (F) When trying to initialize the random seed for hashes, Perl could
7785 not get any randomness out of your system. This usually indicates
7786 Something Very Wrong.
7788 =item Zero length \N{} in regex; marked by S<<-- HERE> in m/%s/
7790 (F) Named Unicode character escapes (C<\N{...}>) may return a zero-length
7791 sequence. Such an escape was used in an extended character class, i.e.
7792 C<(?[...])>, or under C<use re 'strict'>, which is not permitted. Check
7793 that the correct escape has been used, and the correct charnames handler
7794 is in scope. The S<<-- HERE> shows whereabouts in the regular
7795 expression the problem was discovered.
7801 L<warnings>, L<diagnostics>.