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 $[ is no longer possible
267 (F) When the "array_base" feature is disabled (e.g., under C<use v5.16;>)
268 the special variable C<$[>, which is deprecated, is now a fixed zero value.
270 =item Assignment to both a list and a scalar
272 (F) If you assign to a conditional operator, the 2nd and 3rd arguments
273 must either both be scalars or both be lists. Otherwise Perl won't
274 know which context to supply to the right side.
276 =item Assuming NOT a POSIX class since %s in regex; marked by S<<-- HERE> in m/%s/
278 (W regexp) You had something like these:
283 They look like they might have been meant to be the POSIX classes
284 C<[:alnum:]> or C<[:digit:]>. If so, they should be written:
289 Since these aren't legal POSIX class specifications, but are legal
290 bracketed character classes, Perl treats them as the latter. In the
291 first example, it matches the characters C<":">, C<"[">, C<"a">, C<"l">,
292 C<"m">, C<"n">, and C<"u">.
294 If these weren't meant to be POSIX classes, this warning message is
295 spurious, and can be suppressed by reordering things, such as
303 =item <> at require-statement should be quotes
305 (F) You wrote C<< require <file> >> when you should have written
308 =item Attempt to access disallowed key '%s' in a restricted hash
310 (F) The failing code has attempted to get or set a key which is not in
311 the current set of allowed keys of a restricted hash.
313 =item Attempt to bless into a freed package
315 (F) You wrote C<bless $foo> with one argument after somehow causing
316 the current package to be freed. Perl cannot figure out what to
317 do, so it throws up in hands in despair.
319 =item Attempt to bless into a reference
321 (F) The CLASSNAME argument to the bless() operator is expected to be
322 the name of the package to bless the resulting object into. You've
323 supplied instead a reference to something: perhaps you wrote
329 bless $self, ref($proto) || $proto;
331 If you actually want to bless into the stringified version
332 of the reference supplied, you need to stringify it yourself, for
335 bless $self, "$proto";
337 =item Attempt to clear deleted array
339 (S debugging) An array was assigned to when it was being freed.
340 Freed values are not supposed to be visible to Perl code. This
341 can also happen if XS code calls C<av_clear> from a custom magic
342 callback on the array.
344 =item Attempt to delete disallowed key '%s' from a restricted hash
346 (F) The failing code attempted to delete from a restricted hash a key
347 which is not in its key set.
349 =item Attempt to delete readonly key '%s' from a restricted hash
351 (F) The failing code attempted to delete a key whose value has been
352 declared readonly from a restricted hash.
354 =item Attempt to free non-arena SV: 0x%x
356 (S internal) All SV objects are supposed to be allocated from arenas
357 that will be garbage collected on exit. An SV was discovered to be
358 outside any of those arenas.
360 =item Attempt to free nonexistent shared string '%s'%s
362 (S internal) Perl maintains a reference-counted internal table of
363 strings to optimize the storage and access of hash keys and other
364 strings. This indicates someone tried to decrement the reference count
365 of a string that can no longer be found in the table.
367 =item Attempt to free temp prematurely: SV 0x%x
369 (S debugging) Mortalized values are supposed to be freed by the
370 free_tmps() routine. This indicates that something else is freeing the
371 SV before the free_tmps() routine gets a chance, which means that the
372 free_tmps() routine will be freeing an unreferenced scalar when it does
375 =item Attempt to free unreferenced glob pointers
377 (S internal) The reference counts got screwed up on symbol aliases.
379 =item Attempt to free unreferenced scalar: SV 0x%x
381 (S internal) Perl went to decrement the reference count of a scalar to
382 see if it would go to 0, and discovered that it had already gone to 0
383 earlier, and should have been freed, and in fact, probably was freed.
384 This could indicate that SvREFCNT_dec() was called too many times, or
385 that SvREFCNT_inc() was called too few times, or that the SV was
386 mortalized when it shouldn't have been, or that memory has been
389 =item Attempt to pack pointer to temporary value
391 (W pack) You tried to pass a temporary value (like the result of a
392 function, or a computed expression) to the "p" pack() template. This
393 means the result contains a pointer to a location that could become
394 invalid anytime, even before the end of the current statement. Use
395 literals or global values as arguments to the "p" pack() template to
398 =item Attempt to reload %s aborted.
400 (F) You tried to load a file with C<use> or C<require> that failed to
401 compile once already. Perl will not try to compile this file again
402 unless you delete its entry from %INC. See L<perlfunc/require> and
405 =item Attempt to set length of freed array
407 (W misc) You tried to set the length of an array which has
408 been freed. You can do this by storing a reference to the
409 scalar representing the last index of an array and later
410 assigning through that reference. For example
412 $r = do {my @a; \$#a};
415 =item Attempt to use reference as lvalue in substr
417 (W substr) You supplied a reference as the first argument to substr()
418 used as an lvalue, which is pretty strange. Perhaps you forgot to
419 dereference it first. See L<perlfunc/substr>.
421 =item Attribute "locked" is deprecated, and will disappear in Perl 5.28
423 (D deprecated) You have used the attributes pragma to modify the
424 "locked" attribute on a code reference. The :locked attribute is
425 obsolete, has had no effect since 5005 threads were removed, and
426 will be removed in a Perl 5.28.
428 =item Attribute prototype(%s) discards earlier prototype attribute in same sub
430 (W misc) A sub was declared as sub foo : prototype(A) : prototype(B) {}, for
431 example. Since each sub can only have one prototype, the earlier
432 declaration(s) are discarded while the last one is applied.
434 =item Attribute "unique" is deprecated, and will disappear in Perl 5.28
436 (D deprecated) You have used the attributes pragma to modify
437 the "unique" attribute on an array, hash or scalar reference.
438 The :unique attribute has had no effect since Perl 5.8.8, and
439 will be removed in a Perl 5.28.
441 =item av_reify called on tied array
443 (S debugging) This indicates that something went wrong and Perl got I<very>
444 confused about C<@_> or C<@DB::args> being tied.
446 =item Bad arg length for %s, is %u, should be %d
448 (F) You passed a buffer of the wrong size to one of msgctl(), semctl()
449 or shmctl(). In C parlance, the correct sizes are, respectively,
450 S<sizeof(struct msqid_ds *)>, S<sizeof(struct semid_ds *)>, and
451 S<sizeof(struct shmid_ds *)>.
453 =item Bad evalled substitution pattern
455 (F) You've used the C</e> switch to evaluate the replacement for a
456 substitution, but perl found a syntax error in the code to evaluate,
457 most likely an unexpected right brace '}'.
459 =item Bad filehandle: %s
461 (F) A symbol was passed to something wanting a filehandle, but the
462 symbol has no filehandle associated with it. Perhaps you didn't do an
463 open(), or did it in another package.
465 =item Bad free() ignored
467 (S malloc) An internal routine called free() on something that had never
468 been malloc()ed in the first place. Mandatory, but can be disabled by
469 setting environment variable C<PERL_BADFREE> to 0.
471 This message can be seen quite often with DB_File on systems with "hard"
472 dynamic linking, like C<AIX> and C<OS/2>. It is a bug of C<Berkeley DB>
473 which is left unnoticed if C<DB> uses I<forgiving> system malloc().
477 (P) One of the internal hash routines was passed a null HV pointer.
479 =item Badly placed ()'s
481 (A) You've accidentally run your script through B<csh> instead
482 of Perl. Check the #! line, or manually feed your script into
485 =item Bad name after %s
487 (F) You started to name a symbol by using a package prefix, and then
488 didn't finish the symbol. In particular, you can't interpolate outside
497 $sym = "mypack::$var";
499 =item Bad plugin affecting keyword '%s'
501 (F) An extension using the keyword plugin mechanism violated the
504 =item Bad realloc() ignored
506 (S malloc) An internal routine called realloc() on something that
507 had never been malloc()ed in the first place. Mandatory, but can
508 be disabled by setting the environment variable C<PERL_BADFREE> to 1.
510 =item Bad symbol for array
512 (P) An internal request asked to add an array entry to something that
513 wasn't a symbol table entry.
515 =item Bad symbol for dirhandle
517 (P) An internal request asked to add a dirhandle entry to something
518 that wasn't a symbol table entry.
520 =item Bad symbol for filehandle
522 (P) An internal request asked to add a filehandle entry to something
523 that wasn't a symbol table entry.
525 =item Bad symbol for hash
527 (P) An internal request asked to add a hash entry to something that
528 wasn't a symbol table entry.
530 =item Bad symbol for scalar
532 (P) An internal request asked to add a scalar entry to something that
533 wasn't a symbol table entry.
535 =item Bareword found in conditional
537 (W bareword) The compiler found a bareword where it expected a
538 conditional, which often indicates that an || or && was parsed as part
539 of the last argument of the previous construct, for example:
543 It may also indicate a misspelled constant that has been interpreted as
546 use constant TYPO => 1;
547 if (TYOP) { print "foo" }
549 The C<strict> pragma is useful in avoiding such errors.
551 =item Bareword in require contains "%s"
553 =item Bareword in require maps to disallowed filename "%s"
555 =item Bareword in require maps to empty filename
557 (F) The bareword form of require has been invoked with a filename which could
558 not have been generated by a valid bareword permitted by the parser. You
559 shouldn't be able to get this error from Perl code, but XS code may throw it
560 if it passes an invalid module name to C<Perl_load_module>.
562 =item Bareword in require must not start with a double-colon: "%s"
564 (F) In C<require Bare::Word>, the bareword is not allowed to start with a
565 double-colon. Write C<require ::Foo::Bar> as C<require Foo::Bar> instead.
567 =item Bareword "%s" not allowed while "strict subs" in use
569 (F) With "strict subs" in use, a bareword is only allowed as a
570 subroutine identifier, in curly brackets or to the left of the "=>"
571 symbol. Perhaps you need to predeclare a subroutine?
573 =item Bareword "%s" refers to nonexistent package
575 (W bareword) You used a qualified bareword of the form C<Foo::>, but the
576 compiler saw no other uses of that namespace before that point. Perhaps
577 you need to predeclare a package?
579 =item BEGIN failed--compilation aborted
581 (F) An untrapped exception was raised while executing a BEGIN
582 subroutine. Compilation stops immediately and the interpreter is
585 =item BEGIN not safe after errors--compilation aborted
587 (F) Perl found a C<BEGIN {}> subroutine (or a C<use> directive, which
588 implies a C<BEGIN {}>) after one or more compilation errors had already
589 occurred. Since the intended environment for the C<BEGIN {}> could not
590 be guaranteed (due to the errors), and since subsequent code likely
591 depends on its correct operation, Perl just gave up.
593 =item \%d better written as $%d
595 (W syntax) Outside of patterns, backreferences live on as variables.
596 The use of backslashes is grandfathered on the right-hand side of a
597 substitution, but stylistically it's better to use the variable form
598 because other Perl programmers will expect it, and it works better if
599 there are more than 9 backreferences.
601 =item Binary number > 0b11111111111111111111111111111111 non-portable
603 (W portable) The binary number you specified is larger than 2**32-1
604 (4294967295) and therefore non-portable between systems. See
605 L<perlport> for more on portability concerns.
607 =item bind() on closed socket %s
609 (W closed) You tried to do a bind on a closed socket. Did you forget to
610 check the return value of your socket() call? See L<perlfunc/bind>.
612 =item binmode() on closed filehandle %s
614 (W unopened) You tried binmode() on a filehandle that was never opened.
615 Check your control flow and number of arguments.
617 =item Bit vector size > 32 non-portable
619 (W portable) Using bit vector sizes larger than 32 is non-portable.
621 =item Bizarre copy of %s
623 (P) Perl detected an attempt to copy an internal value that is not
626 =item Bizarre SvTYPE [%d]
628 (P) When starting a new thread or returning values from a thread, Perl
629 encountered an invalid data type.
631 =item Both or neither range ends should be Unicode in regex; marked by
634 (W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
636 In a bracketed character class in a regular expression pattern, you
637 had a range which has exactly one end of it specified using C<\N{}>, and
638 the other end is specified using a non-portable mechanism. Perl treats
639 the range as a Unicode range, that is, all the characters in it are
640 considered to be the Unicode characters, and which may be different code
641 points on some platforms Perl runs on. For example, C<[\N{U+06}-\x08]>
642 is treated as if you had instead said C<[\N{U+06}-\N{U+08}]>, that is it
643 matches the characters whose code points in Unicode are 6, 7, and 8.
644 But that C<\x08> might indicate that you meant something different, so
645 the warning gets raised.
647 =item Buffer overflow in prime_env_iter: %s
649 (W internal) A warning peculiar to VMS. While Perl was preparing to
650 iterate over %ENV, it encountered a logical name or symbol definition
651 which was too long, so it was truncated to the string shown.
653 =item Callback called exit
655 (F) A subroutine invoked from an external package via call_sv()
656 exited by calling exit.
658 =item %s() called too early to check prototype
660 (W prototype) You've called a function that has a prototype before the
661 parser saw a definition or declaration for it, and Perl could not check
662 that the call conforms to the prototype. You need to either add an
663 early prototype declaration for the subroutine in question, or move the
664 subroutine definition ahead of the call to get proper prototype
665 checking. Alternatively, if you are certain that you're calling the
666 function correctly, you may put an ampersand before the name to avoid
667 the warning. See L<perlsub>.
671 (F) You passed an invalid number (like an infinity or not-a-number) to C<chr>.
673 =item Cannot compress %f in pack
675 (F) You tried compressing an infinity or not-a-number as an unsigned
676 integer with BER, which makes no sense.
678 =item Cannot compress integer in pack
680 (F) An argument to pack("w",...) was too large to compress.
681 The BER compressed integer format can only be used with positive
682 integers, and you attempted to compress a very large number (> 1e308).
683 See L<perlfunc/pack>.
685 =item Cannot compress negative numbers in pack
687 (F) An argument to pack("w",...) was negative. The BER compressed integer
688 format can only be used with positive integers. See L<perlfunc/pack>.
690 =item Cannot convert a reference to %s to typeglob
692 (F) You manipulated Perl's symbol table directly, stored a reference
693 in it, then tried to access that symbol via conventional Perl syntax.
694 The access triggers Perl to autovivify that typeglob, but it there is
695 no legal conversion from that type of reference to a typeglob.
697 =item Cannot copy to %s
699 (P) Perl detected an attempt to copy a value to an internal type that cannot
700 be directly assigned to.
702 =item Cannot find encoding "%s"
704 (S io) You tried to apply an encoding that did not exist to a filehandle,
705 either with open() or binmode().
707 =item Cannot pack %f with '%c'
709 (F) You tried converting an infinity or not-a-number to an integer,
710 which makes no sense.
712 =item Cannot printf %f with '%c'
714 (F) You tried printing an infinity or not-a-number as a character (%c),
715 which makes no sense. Maybe you meant '%s', or just stringifying it?
717 =item Cannot set tied @DB::args
719 (F) C<caller> tried to set C<@DB::args>, but found it tied. Tying C<@DB::args>
720 is not supported. (Before this error was added, it used to crash.)
722 =item Cannot tie unreifiable array
724 (P) You somehow managed to call C<tie> on an array that does not
725 keep a reference count on its arguments and cannot be made to
726 do so. Such arrays are not even supposed to be accessible to
727 Perl code, but are only used internally.
729 =item Cannot yet reorder sv_catpvfn() arguments from va_list
731 (F) Some XS code tried to use C<sv_catpvfn()> or a related function with a
732 format string that specifies explicit indexes for some of the elements, and
733 using a C-style variable-argument list (a C<va_list>). This is not currently
734 supported. XS authors wanting to do this must instead construct a C array
735 of C<SV*> scalars containing the arguments.
737 =item Can only compress unsigned integers in pack
739 (F) An argument to pack("w",...) was not an integer. The BER compressed
740 integer format can only be used with positive integers, and you attempted
741 to compress something else. See L<perlfunc/pack>.
743 =item Can't bless non-reference value
745 (F) Only hard references may be blessed. This is how Perl "enforces"
746 encapsulation of objects. See L<perlobj>.
748 =item Can't "break" in a loop topicalizer
750 (F) You called C<break>, but you're in a C<foreach> block rather than
751 a C<given> block. You probably meant to use C<next> or C<last>.
753 =item Can't "break" outside a given block
755 (F) You called C<break>, but you're not inside a C<given> block.
757 =item Can't call method "%s" on an undefined value
759 (F) You used the syntax of a method call, but the slot filled by the
760 object reference or package name contains an undefined value. Something
761 like this will reproduce the error:
764 process $BADREF 1,2,3;
765 $BADREF->process(1,2,3);
767 =item Can't call method "%s" on unblessed reference
769 (F) A method call must know in what package it's supposed to run. It
770 ordinarily finds this out from the object reference you supply, but you
771 didn't supply an object reference in this case. A reference isn't an
772 object reference until it has been blessed. See L<perlobj>.
774 =item Can't call method "%s" without a package or object reference
776 (F) You used the syntax of a method call, but the slot filled by the
777 object reference or package name contains an expression that returns a
778 defined value which is neither an object reference nor a package name.
779 Something like this will reproduce the error:
782 process $BADREF 1,2,3;
783 $BADREF->process(1,2,3);
785 =item Can't call mro_isa_changed_in() on anonymous symbol table
787 (P) Perl got confused as to whether a hash was a plain hash or a
788 symbol table hash when trying to update @ISA caches.
790 =item Can't call mro_method_changed_in() on anonymous symbol table
792 (F) An XS module tried to call C<mro_method_changed_in> on a hash that was
793 not attached to the symbol table.
795 =item Can't chdir to %s
797 (F) You called C<perl -x/foo/bar>, but F</foo/bar> is not a directory
798 that you can chdir to, possibly because it doesn't exist.
800 =item Can't check filesystem of script "%s" for nosuid
802 (P) For some reason you can't check the filesystem of the script for
805 =item Can't coerce %s to %s in %s
807 (F) Certain types of SVs, in particular real symbol table entries
808 (typeglobs), can't be forced to stop being what they are. So you can't
818 but then $foo no longer contains a glob.
820 =item Can't "continue" outside a when block
822 (F) You called C<continue>, but you're not inside a C<when>
825 =item Can't create pipe mailbox
827 (P) An error peculiar to VMS. The process is suffering from exhausted
828 quotas or other plumbing problems.
830 =item Can't declare %s in "%s"
832 (F) Only scalar, array, and hash variables may be declared as "my", "our" or
833 "state" variables. They must have ordinary identifiers as names.
835 =item Can't "default" outside a topicalizer
837 (F) You have used a C<default> block that is neither inside a
838 C<foreach> loop nor a C<given> block. (Note that this error is
839 issued on exit from the C<default> block, so you won't get the
840 error if you use an explicit C<continue>.)
842 =item Can't determine class of operator %s, assuming BASEOP
844 (S) This warning indicates something wrong in the internals of perl.
845 Perl was trying to find the class (e.g. LISTOP) of a particular OP,
846 and was unable to do so. This is likely to be due to a bug in the perl
847 internals, or due to a bug in XS code which manipulates perl optrees.
849 =item Can't do inplace edit: %s is not a regular file
851 (S inplace) You tried to use the B<-i> switch on a special file, such as
852 a file in /dev, a FIFO or an uneditable directory. The file was ignored.
854 =item Can't do inplace edit on %s: %s
856 (S inplace) The creation of the new file failed for the indicated
859 =item Can't do inplace edit without backup
861 (F) You're on a system such as MS-DOS that gets confused if you try
862 reading from a deleted (but still opened) file. You have to say
863 C<-i.bak>, or some such.
865 =item Can't do inplace edit: %s would not be unique
867 (S inplace) Your filesystem does not support filenames longer than 14
868 characters and Perl was unable to create a unique filename during
869 inplace editing with the B<-i> switch. The file was ignored.
871 =item Can't do %s("%s") on non-UTF-8 locale; resolved to "%s".
873 (W locale) You are 1) running under "C<use locale>"; 2) the current
874 locale is not a UTF-8 one; 3) you tried to do the designated case-change
875 operation on the specified Unicode character; and 4) the result of this
876 operation would mix Unicode and locale rules, which likely conflict.
877 Mixing of different rule types is forbidden, so the operation was not
878 done; instead the result is the indicated value, which is the best
879 available that uses entirely Unicode rules. That turns out to almost
880 always be the original character, unchanged.
882 It is generally a bad idea to mix non-UTF-8 locales and Unicode, and
883 this issue is one of the reasons why. This warning is raised when
884 Unicode rules would normally cause the result of this operation to
885 contain a character that is in the range specified by the locale,
886 0..255, and hence is subject to the locale's rules, not Unicode's.
888 If you are using locale purely for its characteristics related to things
889 like its numeric and time formatting (and not C<LC_CTYPE>), consider
890 using a restricted form of the locale pragma (see L<perllocale/The "use
891 locale" pragma>) like "S<C<use locale ':not_characters'>>".
893 Note that failed case-changing operations done as a result of
894 case-insensitive C</i> regular expression matching will show up in this
895 warning as having the C<fc> operation (as that is what the regular
896 expression engine calls behind the scenes.)
898 =item Can't do waitpid with flags
900 (F) This machine doesn't have either waitpid() or wait4(), so only
901 waitpid() without flags is emulated.
903 =item Can't emulate -%s on #! line
905 (F) The #! line specifies a switch that doesn't make sense at this
906 point. For example, it'd be kind of silly to put a B<-x> on the #!
909 =item Can't %s %s-endian %ss on this platform
911 (F) Your platform's byte-order is neither big-endian nor little-endian,
912 or it has a very strange pointer size. Packing and unpacking big- or
913 little-endian floating point values and pointers may not be possible.
914 See L<perlfunc/pack>.
916 =item Can't exec "%s": %s
918 (W exec) A system(), exec(), or piped open call could not execute the
919 named program for the indicated reason. Typical reasons include: the
920 permissions were wrong on the file, the file wasn't found in
921 C<$ENV{PATH}>, the executable in question was compiled for another
922 architecture, or the #! line in a script points to an interpreter that
923 can't be run for similar reasons. (Or maybe your system doesn't support
928 (F) Perl was trying to execute the indicated program for you because
929 that's what the #! line said. If that's not what you wanted, you may
930 need to mention "perl" on the #! line somewhere.
932 =item Can't execute %s
934 (F) You used the B<-S> switch, but the copies of the script to execute
935 found in the PATH did not have correct permissions.
937 =item Can't find an opnumber for "%s"
939 (F) A string of a form C<CORE::word> was given to prototype(), but there
940 is no builtin with the name C<word>.
942 =item Can't find label %s
944 (F) You said to goto a label that isn't mentioned anywhere that it's
945 possible for us to go to. See L<perlfunc/goto>.
947 =item Can't find %s on PATH
949 (F) You used the B<-S> switch, but the script to execute could not be
952 =item Can't find %s on PATH, '.' not in PATH
954 (F) You used the B<-S> switch, but the script to execute could not be
955 found in the PATH, or at least not with the correct permissions. The
956 script exists in the current directory, but PATH prohibits running it.
958 =item Can't find string terminator %s anywhere before EOF
960 (F) Perl strings can stretch over multiple lines. This message means
961 that the closing delimiter was omitted. Because bracketed quotes count
962 nesting levels, the following is missing its final parenthesis:
964 print q(The character '(' starts a side comment.);
966 If you're getting this error from a here-document, you may have
967 included unseen whitespace before or after your closing tag or there
968 may not be a linebreak after it. A good programmer's editor will have
969 a way to help you find these characters (or lack of characters). See
970 L<perlop> for the full details on here-documents.
972 =item Can't find Unicode property definition "%s"
974 =item Can't find Unicode property definition "%s" in regex; marked by <-- HERE in m/%s/
976 (F) The named property which you specified via C<\p> or C<\P> is not one
977 known to Perl. Perhaps you misspelled the name? See
978 L<perluniprops/Properties accessible through \p{} and \P{}>
979 for a complete list of available official
980 properties. If it is a
981 L<user-defined property|perlunicode/User-Defined Character Properties>
982 it must have been defined by the time the regular expression is
985 If you didn't mean to use a Unicode property, escape the C<\p>, either
986 by C<\\p> (just the C<\p>) or by C<\Q\p> (the rest of the string, or
991 (F) A fatal error occurred while trying to fork while opening a
994 =item Can't fork, trying again in 5 seconds
996 (W pipe) A fork in a piped open failed with EAGAIN and will be retried
999 =item Can't get filespec - stale stat buffer?
1001 (S) A warning peculiar to VMS. This arises because of the difference
1002 between access checks under VMS and under the Unix model Perl assumes.
1003 Under VMS, access checks are done by filename, rather than by bits in
1004 the stat buffer, so that ACLs and other protections can be taken into
1005 account. Unfortunately, Perl assumes that the stat buffer contains all
1006 the necessary information, and passes it, instead of the filespec, to
1007 the access-checking routine. It will try to retrieve the filespec using
1008 the device name and FID present in the stat buffer, but this works only
1009 if you haven't made a subsequent call to the CRTL stat() routine,
1010 because the device name is overwritten with each call. If this warning
1011 appears, the name lookup failed, and the access-checking routine gave up
1012 and returned FALSE, just to be conservative. (Note: The access-checking
1013 routine knows about the Perl C<stat> operator and file tests, so you
1014 shouldn't ever see this warning in response to a Perl command; it arises
1015 only if some internal code takes stat buffers lightly.)
1017 =item Can't get pipe mailbox device name
1019 (P) An error peculiar to VMS. After creating a mailbox to act as a
1020 pipe, Perl can't retrieve its name for later use.
1022 =item Can't get SYSGEN parameter value for MAXBUF
1024 (P) An error peculiar to VMS. Perl asked $GETSYI how big you want your
1025 mailbox buffers to be, and didn't get an answer.
1027 =item Can't "goto" into the middle of a foreach loop
1029 (F) A "goto" statement was executed to jump into the middle of a foreach
1030 loop. You can't get there from here. See L<perlfunc/goto>.
1032 =item Can't "goto" out of a pseudo block
1034 (F) A "goto" statement was executed to jump out of what might look like
1035 a block, except that it isn't a proper block. This usually occurs if
1036 you tried to jump out of a sort() block or subroutine, which is a no-no.
1037 See L<perlfunc/goto>.
1039 =item Can't goto subroutine from an eval-%s
1041 (F) The "goto subroutine" call can't be used to jump out of an eval
1044 =item Can't goto subroutine from a sort sub (or similar callback)
1046 (F) The "goto subroutine" call can't be used to jump out of the
1047 comparison sub for a sort(), or from a similar callback (such
1048 as the reduce() function in List::Util).
1050 =item Can't goto subroutine outside a subroutine
1052 (F) The deeply magical "goto subroutine" call can only replace one
1053 subroutine call for another. It can't manufacture one out of whole
1054 cloth. In general you should be calling it out of only an AUTOLOAD
1055 routine anyway. See L<perlfunc/goto>.
1057 =item Can't ignore signal CHLD, forcing to default
1059 (W signal) Perl has detected that it is being run with the SIGCHLD
1060 signal (sometimes known as SIGCLD) disabled. Since disabling this
1061 signal will interfere with proper determination of exit status of child
1062 processes, Perl has reset the signal to its default value. This
1063 situation typically indicates that the parent program under which Perl
1064 may be running (e.g. cron) is being very careless.
1066 =item Can't kill a non-numeric process ID
1068 (F) Process identifiers must be (signed) integers. It is a fatal error to
1069 attempt to kill() an undefined, empty-string or otherwise non-numeric
1072 =item Can't "last" outside a loop block
1074 (F) A "last" statement was executed to break out of the current block,
1075 except that there's this itty bitty problem called there isn't a current
1076 block. Note that an "if" or "else" block doesn't count as a "loopish"
1077 block, as doesn't a block given to sort(), map() or grep(). You can
1078 usually double the curlies to get the same effect though, because the
1079 inner curlies will be considered a block that loops once. See
1082 =item Can't linearize anonymous symbol table
1084 (F) Perl tried to calculate the method resolution order (MRO) of a
1085 package, but failed because the package stash has no name.
1087 =item Can't load '%s' for module %s
1089 (F) The module you tried to load failed to load a dynamic extension.
1090 This may either mean that you upgraded your version of perl to one
1091 that is incompatible with your old dynamic extensions (which is known
1092 to happen between major versions of perl), or (more likely) that your
1093 dynamic extension was built against an older version of the library
1094 that is installed on your system. You may need to rebuild your old
1097 =item Can't localize lexical variable %s
1099 (F) You used local on a variable name that was previously declared as a
1100 lexical variable using "my" or "state". This is not allowed. If you
1101 want to localize a package variable of the same name, qualify it with
1104 =item Can't localize through a reference
1106 (F) You said something like C<local $$ref>, which Perl can't currently
1107 handle, because when it goes to restore the old value of whatever $ref
1108 pointed to after the scope of the local() is finished, it can't be sure
1109 that $ref will still be a reference.
1111 =item Can't locate %s
1113 (F) You said to C<do> (or C<require>, or C<use>) a file that couldn't be found.
1114 Perl looks for the file in all the locations mentioned in @INC, unless
1115 the file name included the full path to the file. Perhaps you need
1116 to set the PERL5LIB or PERL5OPT environment variable to say where the
1117 extra library is, or maybe the script needs to add the library name
1118 to @INC. Or maybe you just misspelled the name of the file. See
1119 L<perlfunc/require> and L<lib>.
1121 =item Can't locate auto/%s.al in @INC
1123 (F) A function (or method) was called in a package which allows
1124 autoload, but there is no function to autoload. Most probable causes
1125 are a misprint in a function/method name or a failure to C<AutoSplit>
1126 the file, say, by doing C<make install>.
1128 =item Can't locate loadable object for module %s in @INC
1130 (F) The module you loaded is trying to load an external library, like
1131 for example, F<foo.so> or F<bar.dll>, but the L<DynaLoader> module was
1132 unable to locate this library. See L<DynaLoader>.
1134 =item Can't locate object method "%s" via package "%s"
1136 (F) You called a method correctly, and it correctly indicated a package
1137 functioning as a class, but that package doesn't define that particular
1138 method, nor does any of its base classes. See L<perlobj>.
1140 =item Can't locate object method "%s" via package "%s" (perhaps you forgot
1143 (F) You called a method on a class that did not exist, and the method
1144 could not be found in UNIVERSAL. This often means that a method
1145 requires a package that has not been loaded.
1147 =item Can't locate package %s for @%s::ISA
1149 (W syntax) The @ISA array contained the name of another package that
1150 doesn't seem to exist.
1152 =item Can't locate PerlIO%s
1154 (F) You tried to use in open() a PerlIO layer that does not exist,
1155 e.g. open(FH, ">:nosuchlayer", "somefile").
1157 =item Can't make list assignment to %ENV on this system
1159 (F) List assignment to %ENV is not supported on some systems, notably
1162 =item Can't make loaded symbols global on this platform while loading %s
1164 (S) A module passed the flag 0x01 to DynaLoader::dl_load_file() to request
1165 that symbols from the stated file are made available globally within the
1166 process, but that functionality is not available on this platform. Whilst
1167 the module likely will still work, this may prevent the perl interpreter
1168 from loading other XS-based extensions which need to link directly to
1169 functions defined in the C or XS code in the stated file.
1171 =item Can't modify %s in %s
1173 (F) You aren't allowed to assign to the item indicated, or otherwise try
1174 to change it, such as with an auto-increment.
1176 =item Can't modify nonexistent substring
1178 (P) The internal routine that does assignment to a substr() was handed
1181 =item Can't modify non-lvalue subroutine call of &%s
1183 (F) Subroutines meant to be used in lvalue context should be declared as
1184 such. See L<perlsub/"Lvalue subroutines">.
1186 =item Can't modify reference to %s in %s assignment
1188 (F) Only a limited number of constructs can be used as the argument to a
1189 reference constructor on the left-hand side of an assignment, and what
1190 you used was not one of them. See L<perlref/Assigning to References>.
1192 =item Can't modify reference to localized parenthesized array in list
1195 (F) Assigning to C<\local(@array)> or C<\(local @array)> is not supported, as
1196 it is not clear exactly what it should do. If you meant to make @array
1197 refer to some other array, use C<\@array = \@other_array>. If you want to
1198 make the elements of @array aliases of the scalars referenced on the
1199 right-hand side, use C<\(@array) = @scalar_refs>.
1201 =item Can't modify reference to parenthesized hash in list assignment
1203 (F) Assigning to C<\(%hash)> is not supported. If you meant to make %hash
1204 refer to some other hash, use C<\%hash = \%other_hash>. If you want to
1205 make the elements of %hash into aliases of the scalars referenced on the
1206 right-hand side, use a hash slice: C<\@hash{@keys} = @those_scalar_refs>.
1208 =item Can't msgrcv to read-only var
1210 (F) The target of a msgrcv must be modifiable to be used as a receive
1213 =item Can't "next" outside a loop block
1215 (F) A "next" statement was executed to reiterate the current block, but
1216 there isn't a current block. Note that an "if" or "else" block doesn't
1217 count as a "loopish" block, as doesn't a block given to sort(), map() or
1218 grep(). You can usually double the curlies to get the same effect
1219 though, because the inner curlies will be considered a block that loops
1220 once. See L<perlfunc/next>.
1222 =item Can't open %s: %s
1224 (S inplace) The implicit opening of a file through use of the C<< <> >>
1225 filehandle, either implicitly under the C<-n> or C<-p> command-line
1226 switches, or explicitly, failed for the indicated reason. Usually
1227 this is because you don't have read permission for a file which
1228 you named on the command line.
1230 (F) You tried to call perl with the B<-e> switch, but F</dev/null> (or
1231 your operating system's equivalent) could not be opened.
1233 =item Can't open a reference
1235 (W io) You tried to open a scalar reference for reading or writing,
1236 using the 3-arg open() syntax:
1240 but your version of perl is compiled without perlio, and this form of
1241 open is not supported.
1243 =item Can't open bidirectional pipe
1245 (W pipe) You tried to say C<open(CMD, "|cmd|")>, which is not supported.
1246 You can try any of several modules in the Perl library to do this, such
1247 as IPC::Open2. Alternately, direct the pipe's output to a file using
1248 ">", and then read it in under a different file handle.
1250 =item Can't open error file %s as stderr
1252 (F) An error peculiar to VMS. Perl does its own command line
1253 redirection, and couldn't open the file specified after '2>' or '2>>' on
1254 the command line for writing.
1256 =item Can't open input file %s as stdin
1258 (F) An error peculiar to VMS. Perl does its own command line
1259 redirection, and couldn't open the file specified after '<' on the
1260 command line for reading.
1262 =item Can't open output file %s as stdout
1264 (F) An error peculiar to VMS. Perl does its own command line
1265 redirection, and couldn't open the file specified after '>' or '>>' on
1266 the command line for writing.
1268 =item Can't open output pipe (name: %s)
1270 (P) An error peculiar to VMS. Perl does its own command line
1271 redirection, and couldn't open the pipe into which to send data destined
1274 =item Can't open perl script "%s": %s
1276 (F) The script you specified can't be opened for the indicated reason.
1278 If you're debugging a script that uses #!, and normally relies on the
1279 shell's $PATH search, the -S option causes perl to do that search, so
1280 you don't have to type the path or C<`which $scriptname`>.
1282 =item Can't read CRTL environ
1284 (S) A warning peculiar to VMS. Perl tried to read an element of %ENV
1285 from the CRTL's internal environment array and discovered the array was
1286 missing. You need to figure out where your CRTL misplaced its environ
1287 or define F<PERL_ENV_TABLES> (see L<perlvms>) so that environ is not
1290 =item Can't redeclare "%s" in "%s"
1292 (F) A "my", "our" or "state" declaration was found within another declaration,
1293 such as C<my ($x, my($y), $z)> or C<our (my $x)>.
1295 =item Can't "redo" outside a loop block
1297 (F) A "redo" statement was executed to restart the current block, but
1298 there isn't a current block. Note that an "if" or "else" block doesn't
1299 count as a "loopish" block, as doesn't a block given to sort(), map()
1300 or grep(). You can usually double the curlies to get the same effect
1301 though, because the inner curlies will be considered a block that
1302 loops once. See L<perlfunc/redo>.
1304 =item Can't remove %s: %s, skipping file
1306 (S inplace) You requested an inplace edit without creating a backup
1307 file. Perl was unable to remove the original file to replace it with
1308 the modified file. The file was left unmodified.
1310 =item Can't rename %s to %s: %s, skipping file
1312 (S inplace) The rename done by the B<-i> switch failed for some reason,
1313 probably because you don't have write permission to the directory.
1315 =item Can't reopen input pipe (name: %s) in binary mode
1317 (P) An error peculiar to VMS. Perl thought stdin was a pipe, and tried
1318 to reopen it to accept binary data. Alas, it failed.
1320 =item Can't represent character for Ox%X on this platform
1322 (F) There is a hard limit to how big a character code point can be due
1323 to the fundamental properties of UTF-8, especially on EBCDIC
1324 platforms. The given code point exceeds that. The only work-around is
1325 to not use such a large code point.
1327 =item Can't reset %ENV on this system
1329 (F) You called C<reset('E')> or similar, which tried to reset
1330 all variables in the current package beginning with "E". In
1331 the main package, that includes %ENV. Resetting %ENV is not
1332 supported on some systems, notably VMS.
1334 =item Can't resolve method "%s" overloading "%s" in package "%s"
1336 (F)(P) Error resolving overloading specified by a method name (as
1337 opposed to a subroutine reference): no such method callable via the
1338 package. If the method name is C<???>, this is an internal error.
1340 =item Can't return %s from lvalue subroutine
1342 (F) Perl detected an attempt to return illegal lvalues (such as
1343 temporary or readonly values) from a subroutine used as an lvalue. This
1346 =item Can't return outside a subroutine
1348 (F) The return statement was executed in mainline code, that is, where
1349 there was no subroutine call to return out of. See L<perlsub>.
1351 =item Can't return %s to lvalue scalar context
1353 (F) You tried to return a complete array or hash from an lvalue
1354 subroutine, but you called the subroutine in a way that made Perl
1355 think you meant to return only one value. You probably meant to
1356 write parentheses around the call to the subroutine, which tell
1357 Perl that the call should be in list context.
1359 =item Can't stat script "%s"
1361 (P) For some reason you can't fstat() the script even though you have it
1362 open already. Bizarre.
1364 =item Can't take log of %g
1366 (F) For ordinary real numbers, you can't take the logarithm of a
1367 negative number or zero. There's a Math::Complex package that comes
1368 standard with Perl, though, if you really want to do that for the
1371 =item Can't take sqrt of %g
1373 (F) For ordinary real numbers, you can't take the square root of a
1374 negative number. There's a Math::Complex package that comes standard
1375 with Perl, though, if you really want to do that.
1377 =item Can't undef active subroutine
1379 (F) You can't undefine a routine that's currently running. You can,
1380 however, redefine it while it's running, and you can even undef the
1381 redefined subroutine while the old routine is running. Go figure.
1383 =item Can't upgrade %s (%d) to %d
1385 (P) The internal sv_upgrade routine adds "members" to an SV, making it
1386 into a more specialized kind of SV. The top several SV types are so
1387 specialized, however, that they cannot be interconverted. This message
1388 indicates that such a conversion was attempted.
1390 =item Can't use '%c' after -mname
1392 (F) You tried to call perl with the B<-m> switch, but you put something
1393 other than "=" after the module name.
1395 =item Can't use a hash as a reference
1397 (F) You tried to use a hash as a reference, as in
1398 C<< %foo->{"bar"} >> or C<< %$ref->{"hello"} >>. Versions of perl
1399 <= 5.22.0 used to allow this syntax, but shouldn't
1400 have. This was deprecated in perl 5.6.1.
1402 =item Can't use an array as a reference
1404 (F) You tried to use an array as a reference, as in
1405 C<< @foo->[23] >> or C<< @$ref->[99] >>. Versions of perl <= 5.22.0
1406 used to allow this syntax, but shouldn't have. This
1407 was deprecated in perl 5.6.1.
1409 =item Can't use anonymous symbol table for method lookup
1411 (F) The internal routine that does method lookup was handed a symbol
1412 table that doesn't have a name. Symbol tables can become anonymous
1413 for example by undefining stashes: C<undef %Some::Package::>.
1415 =item Can't use an undefined value as %s reference
1417 (F) A value used as either a hard reference or a symbolic reference must
1418 be a defined value. This helps to delurk some insidious errors.
1420 =item Can't use bareword ("%s") as %s ref while "strict refs" in use
1422 (F) Only hard references are allowed by "strict refs". Symbolic
1423 references are disallowed. See L<perlref>.
1425 =item Can't use %! because Errno.pm is not available
1427 (F) The first time the C<%!> hash is used, perl automatically loads the
1428 Errno.pm module. The Errno module is expected to tie the %! hash to
1429 provide symbolic names for C<$!> errno values.
1431 =item Can't use both '<' and '>' after type '%c' in %s
1433 (F) A type cannot be forced to have both big-endian and little-endian
1434 byte-order at the same time, so this combination of modifiers is not
1435 allowed. See L<perlfunc/pack>.
1437 =item Can't use 'defined(@array)' (Maybe you should just omit the defined()?)
1439 (F) defined() is not useful on arrays because it
1440 checks for an undefined I<scalar> value. If you want to see if the
1441 array is empty, just use C<if (@array) { # not empty }> for example.
1443 =item Can't use 'defined(%hash)' (Maybe you should just omit the defined()?)
1445 (F) C<defined()> is not usually right on hashes.
1447 Although C<defined %hash> is false on a plain not-yet-used hash, it
1448 becomes true in several non-obvious circumstances, including iterators,
1449 weak references, stash names, even remaining true after C<undef %hash>.
1450 These things make C<defined %hash> fairly useless in practice, so it now
1451 generates a fatal error.
1453 If a check for non-empty is what you wanted then just put it in boolean
1454 context (see L<perldata/Scalar values>):
1460 If you had C<defined %Foo::Bar::QUUX> to check whether such a package
1461 variable exists then that's never really been reliable, and isn't
1462 a good way to enquire about the features of a package, or whether
1465 =item Can't use %s for loop variable
1467 (P) The parser got confused when trying to parse a C<foreach> loop.
1469 =item Can't use global %s in "%s"
1471 (F) You tried to declare a magical variable as a lexical variable. This
1472 is not allowed, because the magic can be tied to only one location
1473 (namely the global variable) and it would be incredibly confusing to
1474 have variables in your program that looked like magical variables but
1477 =item Can't use '%c' in a group with different byte-order in %s
1479 (F) You attempted to force a different byte-order on a type
1480 that is already inside a group with a byte-order modifier.
1481 For example you cannot force little-endianness on a type that
1482 is inside a big-endian group.
1484 =item Can't use "my %s" in sort comparison
1486 (F) The global variables $a and $b are reserved for sort comparisons.
1487 You mentioned $a or $b in the same line as the <=> or cmp operator,
1488 and the variable had earlier been declared as a lexical variable.
1489 Either qualify the sort variable with the package name, or rename the
1492 =item Can't use %s ref as %s ref
1494 (F) You've mixed up your reference types. You have to dereference a
1495 reference of the type needed. You can use the ref() function to
1496 test the type of the reference, if need be.
1498 =item Can't use string ("%s") as %s ref while "strict refs" in use
1500 =item Can't use string ("%s"...) as %s ref while "strict refs" in use
1502 (F) You've told Perl to dereference a string, something which
1503 C<use strict> blocks to prevent it happening accidentally. See
1504 L<perlref/"Symbolic references">. This can be triggered by an C<@> or C<$>
1505 in a double-quoted string immediately before interpolating a variable,
1506 for example in C<"user @$twitter_id">, which says to treat the contents
1507 of C<$twitter_id> as an array reference; use a C<\> to have a literal C<@>
1508 symbol followed by the contents of C<$twitter_id>: C<"user \@$twitter_id">.
1510 =item Can't use subscript on %s
1512 (F) The compiler tried to interpret a bracketed expression as a
1513 subscript. But to the left of the brackets was an expression that
1514 didn't look like a hash or array reference, or anything else subscriptable.
1516 =item Can't use \%c to mean $%c in expression
1518 (W syntax) In an ordinary expression, backslash is a unary operator that
1519 creates a reference to its argument. The use of backslash to indicate a
1520 backreference to a matched substring is valid only as part of a regular
1521 expression pattern. Trying to do this in ordinary Perl code produces a
1522 value that prints out looking like SCALAR(0xdecaf). Use the $1 form
1525 =item Can't weaken a nonreference
1527 (F) You attempted to weaken something that was not a reference. Only
1528 references can be weakened.
1530 =item Can't "when" outside a topicalizer
1532 (F) You have used a when() block that is neither inside a C<foreach>
1533 loop nor a C<given> block. (Note that this error is issued on exit
1534 from the C<when> block, so you won't get the error if the match fails,
1535 or if you use an explicit C<continue>.)
1537 =item Can't x= to read-only value
1539 (F) You tried to repeat a constant value (often the undefined value)
1540 with an assignment operator, which implies modifying the value itself.
1541 Perhaps you need to copy the value to a temporary, and repeat that.
1543 =item Character following "\c" must be printable ASCII
1545 (F) In C<\cI<X>>, I<X> must be a printable (non-control) ASCII character.
1547 Note that ASCII characters that don't map to control characters are
1548 discouraged, and will generate the warning (when enabled)
1549 L</""\c%c" is more clearly written simply as "%s"">.
1551 =item Character following \%c must be '{' or a single-character Unicode property name in regex; marked by <-- HERE in m/%s/
1553 (F) (In the above the C<%c> is replaced by either C<p> or C<P>.) You
1554 specified something that isn't a legal Unicode property name. Most
1555 Unicode properties are specified by C<\p{...}>. But if the name is a
1556 single character one, the braces may be omitted.
1558 =item Character in 'C' format wrapped in pack
1564 where $x is either less than 0 or more than 255; the C<"C"> format is
1565 only for encoding native operating system characters (ASCII, EBCDIC,
1566 and so on) and not for Unicode characters, so Perl behaved as if you meant
1570 If you actually want to pack Unicode codepoints, use the C<"U"> format
1573 =item Character in 'c' format wrapped in pack
1579 where $x is either less than -128 or more than 127; the C<"c"> format
1580 is only for encoding native operating system characters (ASCII, EBCDIC,
1581 and so on) and not for Unicode characters, so Perl behaved as if you meant
1583 pack("c", $x & 255);
1585 If you actually want to pack Unicode codepoints, use the C<"U"> format
1588 =item Character in '%c' format wrapped in unpack
1590 (W unpack) You tried something like
1592 unpack("H", "\x{2a1}")
1594 where the format expects to process a byte (a character with a value
1595 below 256), but a higher value was provided instead. Perl uses the
1596 value modulus 256 instead, as if you had provided:
1598 unpack("H", "\x{a1}")
1600 =item Character in 'W' format wrapped in pack
1606 where $x is either less than 0 or more than 255. However, C<U0>-mode
1607 expects all values to fall in the interval [0, 255], so Perl behaved
1610 pack("U0W", $x & 255)
1612 =item Character(s) in '%c' format wrapped in pack
1614 (W pack) You tried something like
1616 pack("u", "\x{1f3}b")
1618 where the format expects to process a sequence of bytes (character with a
1619 value below 256), but some of the characters had a higher value. Perl
1620 uses the character values modulus 256 instead, as if you had provided:
1622 pack("u", "\x{f3}b")
1624 =item Character(s) in '%c' format wrapped in unpack
1626 (W unpack) You tried something like
1628 unpack("s", "\x{1f3}b")
1630 where the format expects to process a sequence of bytes (character with a
1631 value below 256), but some of the characters had a higher value. Perl
1632 uses the character values modulus 256 instead, as if you had provided:
1634 unpack("s", "\x{f3}b")
1636 =item charnames alias definitions may not contain a sequence of multiple spaces
1638 (F) You defined a character name which had multiple space characters
1639 in a row. Change them to single spaces. Usually these names are
1640 defined in the C<:alias> import argument to C<use charnames>, but they
1641 could be defined by a translator installed into C<$^H{charnames}>. See
1642 L<charnames/CUSTOM ALIASES>.
1644 =item charnames alias definitions may not contain trailing white-space
1646 (F) You defined a character name which ended in a space
1647 character. Remove the trailing space(s). Usually these names are
1648 defined in the C<:alias> import argument to C<use charnames>, but they
1649 could be defined by a translator installed into C<$^H{charnames}>.
1650 See L<charnames/CUSTOM ALIASES>.
1652 =item chdir() on unopened filehandle %s
1654 (W unopened) You tried chdir() on a filehandle that was never opened.
1656 =item "\c%c" is more clearly written simply as "%s"
1658 (W syntax) The C<\cI<X>> construct is intended to be a way to specify
1659 non-printable characters. You used it for a printable one, which
1660 is better written as simply itself, perhaps preceded by a backslash
1661 for non-word characters. Doing it the way you did is not portable
1662 between ASCII and EBCDIC platforms.
1664 =item Cloning substitution context is unimplemented
1666 (F) Creating a new thread inside the C<s///> operator is not supported.
1668 =item closedir() attempted on invalid dirhandle %s
1670 (W io) The dirhandle you tried to close is either closed or not really
1671 a dirhandle. Check your control flow.
1673 =item close() on unopened filehandle %s
1675 (W unopened) You tried to close a filehandle that was never opened.
1677 =item Closure prototype called
1679 (F) If a closure has attributes, the subroutine passed to an attribute
1680 handler is the prototype that is cloned when a new closure is created.
1681 This subroutine cannot be called.
1683 =item \C no longer supported in regex; marked by S<<-- HERE> in m/%s/
1685 (F) The \C character class used to allow a match of single byte
1686 within a multi-byte utf-8 character, but was removed in v5.24 as
1687 it broke encapsulation and its implementation was extremely buggy.
1688 If you really need to process the individual bytes, you probably
1689 want to convert your string to one where each underlying byte is
1690 stored as a character, with utf8::encode().
1692 =item Code missing after '/'
1694 (F) You had a (sub-)template that ends with a '/'. There must be
1695 another template code following the slash. See L<perlfunc/pack>.
1697 =item Code point 0x%X is not Unicode, and not portable
1699 (S non_unicode) You had a code point that has never been in any
1700 standard, so it is likely that languages other than Perl will NOT
1701 understand it. At one time, it was legal in some standards to have code
1702 points up to 0x7FFF_FFFF, but not higher, and this code point is higher.
1704 Acceptance of these code points is a Perl extension, and you should
1705 expect that nothing other than Perl can handle them; Perl itself on
1706 EBCDIC platforms before v5.24 does not handle them.
1708 Code points above 0xFFFF_FFFF require larger than a 32 bit word.
1710 Perl also makes no guarantees that the representation of these code
1711 points won't change at some point in the future, say when machines
1712 become available that have larger than a 64-bit word. At that time,
1713 files written by an older Perl would require conversion before being
1714 readable by a newer Perl.
1716 =item Code point 0x%X is not Unicode, may not be portable
1718 (S non_unicode) You had a code point above the Unicode maximum
1721 Perl allows strings to contain a superset of Unicode code points, but
1722 these may not be accepted by other languages/systems. Further, even if
1723 these languages/systems accept these large code points, they may have
1724 chosen a different representation for them than the UTF-8-like one that
1725 Perl has, which would mean files are not exchangeable between them and
1728 On EBCDIC platforms, code points above 0x3FFF_FFFF have a different
1729 representation in Perl v5.24 than before, so any file containing these
1730 that was written before that version will require conversion before
1731 being readable by a later Perl.
1733 =item %s: Command not found
1735 (A) You've accidentally run your script through B<csh> or another shell
1736 instead of Perl. Check the #! line, or manually feed your script into
1737 Perl yourself. The #! line at the top of your file could look like
1741 =item %s: command not found
1743 (A) You've accidentally run your script through B<bash> or another shell
1744 instead of Perl. Check the #! line, or manually feed your script into
1745 Perl yourself. The #! line at the top of your file could look like
1749 =item %s: command not found: %s
1751 (A) You've accidentally run your script through B<zsh> or another shell
1752 instead of Perl. Check the #! line, or manually feed your script into
1753 Perl yourself. The #! line at the top of your file could look like
1757 =item Compilation failed in require
1759 (F) Perl could not compile a file specified in a C<require> statement.
1760 Perl uses this generic message when none of the errors that it
1761 encountered were severe enough to halt compilation immediately.
1763 =item Complex regular subexpression recursion limit (%d) exceeded
1765 (W regexp) The regular expression engine uses recursion in complex
1766 situations where back-tracking is required. Recursion depth is limited
1767 to 32766, or perhaps less in architectures where the stack cannot grow
1768 arbitrarily. ("Simple" and "medium" situations are handled without
1769 recursion and are not subject to a limit.) Try shortening the string
1770 under examination; looping in Perl code (e.g. with C<while>) rather than
1771 in the regular expression engine; or rewriting the regular expression so
1772 that it is simpler or backtracks less. (See L<perlfaq2> for information
1773 on I<Mastering Regular Expressions>.)
1775 =item connect() on closed socket %s
1777 (W closed) You tried to do a connect on a closed socket. Did you forget
1778 to check the return value of your socket() call? See
1779 L<perlfunc/connect>.
1781 =item Constant(%s): Call to &{$^H{%s}} did not return a defined value
1783 (F) The subroutine registered to handle constant overloading
1784 (see L<overload>) or a custom charnames handler (see
1785 L<charnames/CUSTOM TRANSLATORS>) returned an undefined value.
1787 =item Constant(%s): $^H{%s} is not defined
1789 (F) The parser found inconsistencies while attempting to define an
1790 overloaded constant. Perhaps you forgot to load the corresponding
1793 =item Constant is not %s reference
1795 (F) A constant value (perhaps declared using the C<use constant> pragma)
1796 is being dereferenced, but it amounts to the wrong type of reference.
1797 The message indicates the type of reference that was expected. This
1798 usually indicates a syntax error in dereferencing the constant value.
1799 See L<perlsub/"Constant Functions"> and L<constant>.
1801 =item Constants from lexical variables potentially modified elsewhere are
1802 deprecated. This will not be allowed in Perl 5.32
1804 (D deprecated) You wrote something like
1807 $sub = sub () { $var };
1809 but $var is referenced elsewhere and could be modified after the C<sub>
1810 expression is evaluated. Either it is explicitly modified elsewhere
1811 (C<$var = 3>) or it is passed to a subroutine or to an operator like
1812 C<printf> or C<map>, which may or may not modify the variable.
1814 Traditionally, Perl has captured the value of the variable at that
1815 point and turned the subroutine into a constant eligible for inlining.
1816 In those cases where the variable can be modified elsewhere, this
1817 breaks the behavior of closures, in which the subroutine captures
1818 the variable itself, rather than its value, so future changes to the
1819 variable are reflected in the subroutine's return value.
1821 This usage is deprecated, and will no longer be allowed in Perl 5.32,
1822 making it possible to change the behavior in the future.
1824 If you intended for the subroutine to be eligible for inlining, then
1825 make sure the variable is not referenced elsewhere, possibly by
1829 $sub = sub () { $var2 };
1831 If you do want this subroutine to be a closure that reflects future
1832 changes to the variable that it closes over, add an explicit C<return>:
1835 $sub = sub () { return $var };
1837 =item Constant subroutine %s redefined
1839 (W redefine)(S) You redefined a subroutine which had previously
1840 been eligible for inlining. See L<perlsub/"Constant Functions">
1841 for commentary and workarounds.
1843 =item Constant subroutine %s undefined
1845 (W misc) You undefined a subroutine which had previously been eligible
1846 for inlining. See L<perlsub/"Constant Functions"> for commentary and
1849 =item Constant(%s) unknown
1851 (F) The parser found inconsistencies either while attempting
1852 to define an overloaded constant, or when trying to find the
1853 character name specified in the C<\N{...}> escape. Perhaps you
1854 forgot to load the corresponding L<overload> pragma?
1856 =item :const is experimental
1858 (S experimental::const_attr) The "const" attribute is experimental.
1859 If you want to use the feature, disable the warning with C<no warnings
1860 'experimental::const_attr'>, but know that in doing so you are taking
1861 the risk that your code may break in a future Perl version.
1863 =item :const is not permitted on named subroutines
1865 (F) The "const" attribute causes an anonymous subroutine to be run and
1866 its value captured at the time that it is cloned. Named subroutines are
1867 not cloned like this, so the attribute does not make sense on them.
1869 =item Copy method did not return a reference
1871 (F) The method which overloads "=" is buggy. See
1872 L<overload/Copy Constructor>.
1874 =item &CORE::%s cannot be called directly
1876 (F) You tried to call a subroutine in the C<CORE::> namespace
1877 with C<&foo> syntax or through a reference. Some subroutines
1878 in this package cannot yet be called that way, but must be
1879 called as barewords. Something like this will work:
1881 BEGIN { *shove = \&CORE::push; }
1882 shove @array, 1,2,3; # pushes on to @array
1884 =item CORE::%s is not a keyword
1886 (F) The CORE:: namespace is reserved for Perl keywords.
1888 =item Corrupted regexp opcode %d > %d
1890 (P) This is either an error in Perl, or, if you're using
1891 one, your L<custom regular expression engine|perlreapi>. If not the
1892 latter, report the problem through the L<perlbug> utility.
1894 =item corrupted regexp pointers
1896 (P) The regular expression engine got confused by what the regular
1897 expression compiler gave it.
1899 =item corrupted regexp program
1901 (P) The regular expression engine got passed a regexp program without a
1904 =item Corrupt malloc ptr 0x%x at 0x%x
1906 (P) The malloc package that comes with Perl had an internal failure.
1908 =item Count after length/code in unpack
1910 (F) You had an unpack template indicating a counted-length string, but
1911 you have also specified an explicit size for the string. See
1914 =item Declaring references is experimental
1916 (S experimental::declared_refs) This warning is emitted if you use
1917 a reference constructor on the right-hand side of C<my>, C<state>, C<our>, or
1918 C<local>. Simply suppress the warning if you want to use the feature, but
1919 know that in doing so you are taking the risk of using an experimental
1920 feature which may change or be removed in a future Perl version:
1922 no warnings "experimental::declared_refs";
1923 use feature "declared_refs";
1927 The following are used in lib/diagnostics.t for testing two =items that
1928 share the same description. Changes here need to be propagated to there
1930 =item Deep recursion on anonymous subroutine
1932 =item Deep recursion on subroutine "%s"
1934 (W recursion) This subroutine has called itself (directly or indirectly)
1935 100 times more than it has returned. This probably indicates an
1936 infinite recursion, unless you're writing strange benchmark programs, in
1937 which case it indicates something else.
1939 This threshold can be changed from 100, by recompiling the F<perl> binary,
1940 setting the C pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value.
1942 =item (?(DEFINE)....) does not allow branches in regex; marked by
1943 S<<-- HERE> in m/%s/
1945 (F) You used something like C<(?(DEFINE)...|..)> which is illegal. The
1946 most likely cause of this error is that you left out a parenthesis inside
1947 of the C<....> part.
1949 The S<<-- HERE> shows whereabouts in the regular expression the problem was
1952 =item %s defines neither package nor VERSION--version check failed
1954 (F) You said something like "use Module 42" but in the Module file
1955 there are neither package declarations nor a C<$VERSION>.
1957 =item delete argument is index/value array slice, use array slice
1959 (F) You used index/value array slice syntax (C<%array[...]>) as
1960 the argument to C<delete>. You probably meant C<@array[...]> with
1961 an @ symbol instead.
1963 =item delete argument is key/value hash slice, use hash slice
1965 (F) You used key/value hash slice syntax (C<%hash{...}>) as the argument to
1966 C<delete>. You probably meant C<@hash{...}> with an @ symbol instead.
1968 =item delete argument is not a HASH or ARRAY element or slice
1970 (F) The argument to C<delete> must be either a hash or array element,
1976 or a hash or array slice, such as:
1978 @foo[$bar, $baz, $xyzzy]
1979 @{$ref->[12]}{"susie", "queue"}
1981 =item Delimiter for here document is too long
1983 (F) In a here document construct like C<<<FOO>, the label C<FOO> is too
1984 long for Perl to handle. You have to be seriously twisted to write code
1985 that triggers this error.
1987 =item Deprecated use of my() in false conditional. This will be a fatal error in Perl 5.30
1989 (D deprecated) You used a declaration similar to C<my $x if 0>. There
1990 has been a long-standing bug in Perl that causes a lexical variable
1991 not to be cleared at scope exit when its declaration includes a false
1992 conditional. Some people have exploited this bug to achieve a kind of
1993 static variable. Since we intend to fix this bug, we don't want people
1994 relying on this behavior. You can achieve a similar static effect by
1995 declaring the variable in a separate block outside the function, eg
1997 sub f { my $x if 0; return $x++ }
2001 { my $x; sub f { return $x++ } }
2003 Beginning with perl 5.10.0, you can also use C<state> variables to have
2004 lexicals that are initialized only once (see L<feature>):
2006 sub f { state $x; return $x++ }
2008 This use of C<my()> in a false conditional has been deprecated since
2009 Perl 5.10, and it will become a fatal error in Perl 5.30.
2011 =item DESTROY created new reference to dead object '%s'
2013 (F) A DESTROY() method created a new reference to the object which is
2014 just being DESTROYed. Perl is confused, and prefers to abort rather
2015 than to create a dangling reference.
2017 =item Did not produce a valid header
2019 See L</500 Server error>.
2021 =item %s did not return a true value
2023 (F) A required (or used) file must return a true value to indicate that
2024 it compiled correctly and ran its initialization code correctly. It's
2025 traditional to end such a file with a "1;", though any true value would
2026 do. See L<perlfunc/require>.
2028 =item (Did you mean &%s instead?)
2030 (W misc) You probably referred to an imported subroutine &FOO as $FOO or
2033 =item (Did you mean "local" instead of "our"?)
2035 (W misc) Remember that "our" does not localize the declared global
2036 variable. You have declared it again in the same lexical scope, which
2039 =item (Did you mean $ or @ instead of %?)
2041 (W) You probably said %hash{$key} when you meant $hash{$key} or
2042 @hash{@keys}. On the other hand, maybe you just meant %hash and got
2047 (F) You passed die() an empty string (the equivalent of C<die "">) or
2048 you called it with no args and C<$@> was empty.
2050 =item Document contains no data
2052 See L</500 Server error>.
2054 =item %s does not define %s::VERSION--version check failed
2056 (F) You said something like "use Module 42" but the Module did not
2057 define a C<$VERSION>.
2059 =item '/' does not take a repeat count
2061 (F) You cannot put a repeat count of any kind right after the '/' code.
2062 See L<perlfunc/pack>.
2064 =item Don't know how to get file name
2066 (P) C<PerlIO_getname>, a perl internal I/O function specific to VMS, was
2067 somehow called on another platform. This should not happen.
2069 =item Don't know how to handle magic of type \%o
2071 (P) The internal handling of magical variables has been cursed.
2073 =item do_study: out of memory
2075 (P) This should have been caught by safemalloc() instead.
2077 =item (Do you need to predeclare %s?)
2079 (S syntax) This is an educated guess made in conjunction with the message
2080 "%s found where operator expected". It often means a subroutine or module
2081 name is being referenced that hasn't been declared yet. This may be
2082 because of ordering problems in your file, or because of a missing
2083 "sub", "package", "require", or "use" statement. If you're referencing
2084 something that isn't defined yet, you don't actually have to define the
2085 subroutine or package before the current location. You can use an empty
2086 "sub foo;" or "package FOO;" to enter a "forward" declaration.
2088 =item dump() better written as CORE::dump(). dump() will no longer be available in Perl 5.30
2090 (D deprecated, misc) You used the obsolescent C<dump()> built-in function,
2091 without fully qualifying it as C<CORE::dump()>. Maybe it's a typo.
2093 Use of a unqualified C<dump()> was deprecated in Perl 5.30, and this
2094 will not be available in Perl 5.30.
2096 See L<perlfunc/dump>.
2098 =item dump is not supported
2100 (F) Your machine doesn't support dump/undump.
2102 =item Duplicate free() ignored
2104 (S malloc) An internal routine called free() on something that had
2107 =item Duplicate modifier '%c' after '%c' in %s
2109 (W unpack) You have applied the same modifier more than once after a
2110 type in a pack template. See L<perlfunc/pack>.
2112 =item elseif should be elsif
2114 (S syntax) There is no keyword "elseif" in Perl because Larry thinks
2115 it's ugly. Your code will be interpreted as an attempt to call a method
2116 named "elseif" for the class returned by the following block. This is
2117 unlikely to be what you want.
2119 =item Empty \%c in regex; marked by S<<-- HERE> in m/%s/
2121 =item Empty \%c{} in regex; marked by S<<-- HERE> in m/%s/
2123 (F) C<\p> and C<\P> are used to introduce a named Unicode property, as
2124 described in L<perlunicode> and L<perlre>. You used C<\p> or C<\P> in
2125 a regular expression without specifying the property name.
2127 =item ${^ENCODING} is no longer supported. Its use will be fatal in Perl 5.28
2129 (D deprecated) The special variable C<${^ENCODING}>, formerly used to implement
2130 the C<encoding> pragma, is no longer supported as of Perl 5.26.0.
2132 Setting this variable will become a fatal error in Perl 5.28.
2134 =item entering effective %s failed
2136 (F) While under the C<use filetest> pragma, switching the real and
2137 effective uids or gids failed.
2139 =item %ENV is aliased to %s
2141 (F) You're running under taint mode, and the C<%ENV> variable has been
2142 aliased to another hash, so it doesn't reflect anymore the state of the
2143 program's environment. This is potentially insecure.
2145 =item Error converting file specification %s
2147 (F) An error peculiar to VMS. Because Perl may have to deal with file
2148 specifications in either VMS or Unix syntax, it converts them to a
2149 single form when it must operate on them directly. Either you've passed
2150 an invalid file specification to Perl, or you've found a case the
2151 conversion routines don't handle. Drat.
2153 =item Eval-group in insecure regular expression
2155 (F) Perl detected tainted data when trying to compile a regular
2156 expression that contains the C<(?{ ... })> zero-width assertion, which
2157 is unsafe. See L<perlre/(?{ code })>, and L<perlsec>.
2159 =item Eval-group not allowed at runtime, use re 'eval' in regex m/%s/
2161 (F) Perl tried to compile a regular expression containing the
2162 C<(?{ ... })> zero-width assertion at run time, as it would when the
2163 pattern contains interpolated values. Since that is a security risk,
2164 it is not allowed. If you insist, you may still do this by using the
2165 C<re 'eval'> pragma or by explicitly building the pattern from an
2166 interpolated string at run time and using that in an eval(). See
2167 L<perlre/(?{ code })>.
2169 =item Eval-group not allowed, use re 'eval' in regex m/%s/
2171 (F) A regular expression contained the C<(?{ ... })> zero-width
2172 assertion, but that construct is only allowed when the C<use re 'eval'>
2173 pragma is in effect. See L<perlre/(?{ code })>.
2175 =item EVAL without pos change exceeded limit in regex; marked by
2176 S<<-- HERE> in m/%s/
2178 (F) You used a pattern that nested too many EVAL calls without consuming
2179 any text. Restructure the pattern so that text is consumed.
2181 The S<<-- HERE> shows whereabouts in the regular expression the problem was
2184 =item Excessively long <> operator
2186 (F) The contents of a <> operator may not exceed the maximum size of a
2187 Perl identifier. If you're just trying to glob a long list of
2188 filenames, try using the glob() operator, or put the filenames into a
2189 variable and glob that.
2191 =item exec? I'm not *that* kind of operating system
2193 (F) The C<exec> function is not implemented on some systems, e.g., Symbian
2194 OS. See L<perlport>.
2196 =item Execution of %s aborted due to compilation errors.
2198 (F) The final summary message when a Perl compilation fails.
2200 =item exists argument is not a HASH or ARRAY element or a subroutine
2202 (F) The argument to C<exists> must be a hash or array element or a
2203 subroutine with an ampersand, such as:
2209 =item exists argument is not a subroutine name
2211 (F) The argument to C<exists> for C<exists &sub> must be a subroutine name,
2212 and not a subroutine call. C<exists &sub()> will generate this error.
2214 =item Exiting eval via %s
2216 (W exiting) You are exiting an eval by unconventional means, such as a
2217 goto, or a loop control statement.
2219 =item Exiting format via %s
2221 (W exiting) You are exiting a format by unconventional means, such as a
2222 goto, or a loop control statement.
2224 =item Exiting pseudo-block via %s
2226 (W exiting) You are exiting a rather special block construct (like a
2227 sort block or subroutine) by unconventional means, such as a goto, or a
2228 loop control statement. See L<perlfunc/sort>.
2230 =item Exiting subroutine via %s
2232 (W exiting) You are exiting a subroutine by unconventional means, such
2233 as a goto, or a loop control statement.
2235 =item Exiting substitution via %s
2237 (W exiting) You are exiting a substitution by unconventional means, such
2238 as a return, a goto, or a loop control statement.
2240 =item Expecting close bracket in regex; marked by S<<-- HERE> in m/%s/
2242 (F) You wrote something like
2246 to denote a capturing group of the form
2247 L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>,
2248 but omitted the C<")">.
2250 =item Expecting '(?flags:(?[...' in regex; marked by S<<-- HERE> in m/%s/
2252 (F) The C<(?[...])> extended character class regular expression construct
2253 only allows character classes (including character class escapes like
2254 C<\d>), operators, and parentheses. The one exception is C<(?flags:...)>
2255 containing at least one flag and exactly one C<(?[...])> construct.
2256 This allows a regular expression containing just C<(?[...])> to be
2257 interpolated. If you see this error message, then you probably
2258 have some other C<(?...)> construct inside your character class. See
2259 L<perlrecharclass/Extended Bracketed Character Classes>.
2261 =item Experimental aliasing via reference not enabled
2263 (F) To do aliasing via references, you must first enable the feature:
2265 no warnings "experimental::refaliasing";
2266 use feature "refaliasing";
2269 =item Experimental %s on scalar is now forbidden
2271 (F) An experimental feature added in Perl 5.14 allowed C<each>, C<keys>,
2272 C<push>, C<pop>, C<shift>, C<splice>, C<unshift>, and C<values> to be called with a
2273 scalar argument. This experiment is considered unsuccessful, and
2274 has been removed. The C<postderef> feature may meet your needs better.
2276 =item Experimental subroutine signatures not enabled
2278 (F) To use subroutine signatures, you must first enable them:
2280 no warnings "experimental::signatures";
2281 use feature "signatures";
2282 sub foo ($left, $right) { ... }
2284 =item Explicit blessing to '' (assuming package main)
2286 (W misc) You are blessing a reference to a zero length string. This has
2287 the effect of blessing the reference into the package main. This is
2288 usually not what you want. Consider providing a default target package,
2289 e.g. bless($ref, $p || 'MyPackage');
2291 =item %s: Expression syntax
2293 (A) You've accidentally run your script through B<csh> instead of Perl.
2294 Check the #! line, or manually feed your script into Perl yourself.
2296 =item %s failed--call queue aborted
2298 (F) An untrapped exception was raised while executing a UNITCHECK,
2299 CHECK, INIT, or END subroutine. Processing of the remainder of the
2300 queue of such routines has been prematurely ended.
2302 =item Failed to close in-place edit file %s: %s
2304 (F) Closing an output file from in-place editing, as with the C<-i>
2305 command-line switch, failed.
2307 =item False [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
2309 (W regexp)(F) A character class range must start and end at a literal
2310 character, not another character class like C<\d> or C<[:alpha:]>. The "-"
2311 in your false range is interpreted as a literal "-". In a C<(?[...])>
2312 construct, this is an error, rather than a warning. Consider quoting
2313 the "-", "\-". The S<<-- HERE> shows whereabouts in the regular expression
2314 the problem was discovered. See L<perlre>.
2316 =item Fatal VMS error (status=%d) at %s, line %d
2318 (P) An error peculiar to VMS. Something untoward happened in a VMS
2319 system service or RTL routine; Perl's exit status should provide more
2320 details. The filename in "at %s" and the line number in "line %d" tell
2321 you which section of the Perl source code is distressed.
2323 =item fcntl is not implemented
2325 (F) Your machine apparently doesn't implement fcntl(). What is this, a
2326 PDP-11 or something?
2328 =item FETCHSIZE returned a negative value
2330 (F) A tied array claimed to have a negative number of elements, which
2333 =item Field too wide in 'u' format in pack
2335 (W pack) Each line in an uuencoded string starts with a length indicator
2336 which can't encode values above 63. So there is no point in asking for
2337 a line length bigger than that. Perl will behave as if you specified
2338 C<u63> as the format.
2340 =item File::Glob::glob() will disappear in perl 5.30. Use File::Glob::bsd_glob() instead.
2342 (D deprecated) C<< File::Glob >> has a function called C<< glob >>, which
2343 just calls C<< bsd_glob >>. However, its prototype is different from the
2344 prototype of C<< CORE::glob >>, and hence, C<< File::Glob::glob >> should
2347 C<< File::Glob::glob() >> was deprecated in perl 5.8.0. A deprecation
2348 message was issued from perl 5.26.0 onwards, and the function will
2349 disappear in perl 5.30.0.
2351 Code using C<< File::Glob::glob() >> should call
2352 C<< File::Glob::bsd_glob() >> instead.
2354 =item Filehandle %s opened only for input
2356 (W io) You tried to write on a read-only filehandle. If you intended
2357 it to be a read-write filehandle, you needed to open it with "+<" or
2358 "+>" or "+>>" instead of with "<" or nothing. If you intended only to
2359 write the file, use ">" or ">>". See L<perlfunc/open>.
2361 =item Filehandle %s opened only for output
2363 (W io) You tried to read from a filehandle opened only for writing, If
2364 you intended it to be a read/write filehandle, you needed to open it
2365 with "+<" or "+>" or "+>>" instead of with ">". If you intended only to
2366 read from the file, use "<". See L<perlfunc/open>. Another possibility
2367 is that you attempted to open filedescriptor 0 (also known as STDIN) for
2368 output (maybe you closed STDIN earlier?).
2370 =item Filehandle %s reopened as %s only for input
2372 (W io) You opened for reading a filehandle that got the same filehandle id
2373 as STDOUT or STDERR. This occurred because you closed STDOUT or STDERR
2376 =item Filehandle STDIN reopened as %s only for output
2378 (W io) You opened for writing a filehandle that got the same filehandle id
2379 as STDIN. This occurred because you closed STDIN previously.
2381 =item Final $ should be \$ or $name
2383 (F) You must now decide whether the final $ in a string was meant to be
2384 a literal dollar sign, or was meant to introduce a variable name that
2385 happens to be missing. So you have to put either the backslash or the
2388 =item flock() on closed filehandle %s
2390 (W closed) The filehandle you're attempting to flock() got itself closed
2391 some time before now. Check your control flow. flock() operates on
2392 filehandles. Are you attempting to call flock() on a dirhandle by the
2395 =item Format not terminated
2397 (F) A format must be terminated by a line with a solitary dot. Perl got
2398 to the end of your file without finding such a line.
2400 =item Format %s redefined
2402 (W redefine) You redefined a format. To suppress this warning, say
2405 no warnings 'redefine';
2406 eval "format NAME =...";
2409 =item Found = in conditional, should be ==
2419 (or something like that).
2421 =item %s found where operator expected
2423 (S syntax) The Perl lexer knows whether to expect a term or an operator.
2424 If it sees what it knows to be a term when it was expecting to see an
2425 operator, it gives you this warning. Usually it indicates that an
2426 operator or delimiter was omitted, such as a semicolon.
2428 =item gdbm store returned %d, errno %d, key "%s"
2430 (S) A warning from the GDBM_File extension that a store failed.
2432 =item gethostent not implemented
2434 (F) Your C library apparently doesn't implement gethostent(), probably
2435 because if it did, it'd feel morally obligated to return every hostname
2438 =item get%sname() on closed socket %s
2440 (W closed) You tried to get a socket or peer socket name on a closed
2441 socket. Did you forget to check the return value of your socket() call?
2443 =item getpwnam returned invalid UIC %#o for user "%s"
2445 (S) A warning peculiar to VMS. The call to C<sys$getuai> underlying the
2446 C<getpwnam> operator returned an invalid UIC.
2448 =item getsockopt() on closed socket %s
2450 (W closed) You tried to get a socket option on a closed socket. Did you
2451 forget to check the return value of your socket() call? See
2452 L<perlfunc/getsockopt>.
2454 =item given is experimental
2456 (S experimental::smartmatch) C<given> depends on smartmatch, which
2457 is experimental, so its behavior may change or even be removed
2458 in any future release of perl. See the explanation under
2459 L<perlsyn/Experimental Details on given and when>.
2461 =item Global symbol "%s" requires explicit package name (did you forget to
2464 (F) You've said "use strict" or "use strict vars", which indicates
2465 that all variables must either be lexically scoped (using "my" or "state"),
2466 declared beforehand using "our", or explicitly qualified to say
2467 which package the global variable is in (using "::").
2469 =item glob failed (%s)
2471 (S glob) Something went wrong with the external program(s) used
2472 for C<glob> and C<< <*.c> >>. Usually, this means that you supplied a C<glob>
2473 pattern that caused the external program to fail and exit with a
2474 nonzero status. If the message indicates that the abnormal exit
2475 resulted in a coredump, this may also mean that your csh (C shell)
2476 is broken. If so, you should change all of the csh-related variables
2477 in config.sh: If you have tcsh, make the variables refer to it as
2478 if it were csh (e.g. C<full_csh='/usr/bin/tcsh'>); otherwise, make them
2479 all empty (except that C<d_csh> should be C<'undef'>) so that Perl will
2480 think csh is missing. In either case, after editing config.sh, run
2481 C<./Configure -S> and rebuild Perl.
2483 =item Glob not terminated
2485 (F) The lexer saw a left angle bracket in a place where it was expecting
2486 a term, so it's looking for the corresponding right angle bracket, and
2487 not finding it. Chances are you left some needed parentheses out
2488 earlier in the line, and you really meant a "less than".
2490 =item gmtime(%f) failed
2492 (W overflow) You called C<gmtime> with a number that it could not handle:
2493 too large, too small, or NaN. The returned value is C<undef>.
2495 =item gmtime(%f) too large
2497 (W overflow) You called C<gmtime> with a number that was larger than
2498 it can reliably handle and C<gmtime> probably returned the wrong
2499 date. This warning is also triggered with NaN (the special
2500 not-a-number value).
2502 =item gmtime(%f) too small
2504 (W overflow) You called C<gmtime> with a number that was smaller than
2505 it can reliably handle and C<gmtime> probably returned the wrong date.
2507 =item Got an error from DosAllocMem
2509 (P) An error peculiar to OS/2. Most probably you're using an obsolete
2510 version of Perl, and this should not happen anyway.
2512 =item goto must have label
2514 (F) Unlike with "next" or "last", you're not allowed to goto an
2515 unspecified destination. See L<perlfunc/goto>.
2517 =item Goto undefined subroutine%s
2519 (F) You tried to call a subroutine with C<goto &sub> syntax, but
2520 the indicated subroutine hasn't been defined, or if it was, it
2521 has since been undefined.
2523 =item Group name must start with a non-digit word character in regex; marked by
2524 S<<-- HERE> in m/%s/
2526 (F) Group names must follow the rules for perl identifiers, meaning
2527 they must start with a non-digit word character. A common cause of
2528 this error is using (?&0) instead of (?0). See L<perlre>.
2530 =item ()-group starts with a count
2532 (F) A ()-group started with a count. A count is supposed to follow
2533 something: a template character or a ()-group. See L<perlfunc/pack>.
2535 =item %s had compilation errors.
2537 (F) The final summary message when a C<perl -c> fails.
2539 =item Had to create %s unexpectedly
2541 (S internal) A routine asked for a symbol from a symbol table that ought
2542 to have existed already, but for some reason it didn't, and had to be
2543 created on an emergency basis to prevent a core dump.
2545 =item %s has too many errors
2547 (F) The parser has given up trying to parse the program after 10 errors.
2548 Further error messages would likely be uninformative.
2550 =item Hexadecimal float: exponent overflow
2552 (W overflow) The hexadecimal floating point has a larger exponent
2553 than the floating point supports.
2555 =item Hexadecimal float: exponent underflow
2557 (W overflow) The hexadecimal floating point has a smaller exponent
2558 than the floating point supports. With the IEEE 754 floating point,
2559 this may also mean that the subnormals (formerly known as denormals)
2560 are being used, which may or may not be an error.
2562 =item Hexadecimal float: internal error (%s)
2564 (F) Something went horribly bad in hexadecimal float handling.
2566 =item Hexadecimal float: mantissa overflow
2568 (W overflow) The hexadecimal floating point literal had more bits in
2569 the mantissa (the part between the 0x and the exponent, also known as
2570 the fraction or the significand) than the floating point supports.
2572 =item Hexadecimal float: precision loss
2574 (W overflow) The hexadecimal floating point had internally more
2575 digits than could be output. This can be caused by unsupported
2576 long double formats, or by 64-bit integers not being available
2577 (needed to retrieve the digits under some configurations).
2579 =item Hexadecimal float: unsupported long double format
2581 (F) You have configured Perl to use long doubles but
2582 the internals of the long double format are unknown;
2583 therefore the hexadecimal float output is impossible.
2585 =item Hexadecimal number > 0xffffffff non-portable
2587 (W portable) The hexadecimal number you specified is larger than 2**32-1
2588 (4294967295) and therefore non-portable between systems. See
2589 L<perlport> for more on portability concerns.
2591 =item Identifier too long
2593 (F) Perl limits identifiers (names for variables, functions, etc.) to
2594 about 250 characters for simple names, and somewhat more for compound
2595 names (like C<$A::B>). You've exceeded Perl's limits. Future versions
2596 of Perl are likely to eliminate these arbitrary limitations.
2598 =item Ignoring zero length \N{} in character class in regex; marked by
2599 S<<-- HERE> in m/%s/
2601 (W regexp) Named Unicode character escapes (C<\N{...}>) may return a
2602 zero-length sequence. When such an escape is used in a character
2603 class its behavior is not well defined. Check that the correct
2604 escape has been used, and the correct charname handler is in scope.
2606 =item Illegal binary digit %s
2608 (F) You used a digit other than 0 or 1 in a binary number.
2610 =item Illegal binary digit %s ignored
2612 (W digit) You may have tried to use a digit other than 0 or 1 in a
2613 binary number. Interpretation of the binary number stopped before the
2616 =item Illegal character after '_' in prototype for %s : %s
2618 (W illegalproto) An illegal character was found in a prototype
2619 declaration. The '_' in a prototype must be followed by a ';',
2620 indicating the rest of the parameters are optional, or one of '@'
2621 or '%', since those two will accept 0 or more final parameters.
2623 =item Illegal character \%o (carriage return)
2625 (F) Perl normally treats carriage returns in the program text as
2626 it would any other whitespace, which means you should never see
2627 this error when Perl was built using standard options. For some
2628 reason, your version of Perl appears to have been built without
2629 this support. Talk to your Perl administrator.
2631 =item Illegal character following sigil in a subroutine signature
2633 (F) A parameter in a subroutine signature contained an unexpected character
2634 following the C<$>, C<@> or C<%> sigil character. Normally the sigil
2635 should be followed by the variable name or C<=> etc. Perhaps you are
2636 trying use a prototype while in the scope of C<use feature 'signatures'>?
2639 sub foo ($$) {} # legal - a prototype
2641 use feature 'signatures;
2642 sub foo ($$) {} # illegal - was expecting a signature
2644 :prototype($$) {} # legal
2647 =item Illegal character in prototype for %s : %s
2649 (W illegalproto) An illegal character was found in a prototype declaration.
2650 Legal characters in prototypes are $, @, %, *, ;, [, ], &, \, and +.
2651 Perhaps you were trying to write a subroutine signature but didn't enable
2652 that feature first (C<use feature 'signatures'>), so your signature was
2653 instead interpreted as a bad prototype.
2655 =item Illegal declaration of anonymous subroutine
2657 (F) When using the C<sub> keyword to construct an anonymous subroutine,
2658 you must always specify a block of code. See L<perlsub>.
2660 =item Illegal declaration of subroutine %s
2662 (F) A subroutine was not declared correctly. See L<perlsub>.
2664 =item Illegal division by zero
2666 (F) You tried to divide a number by 0. Either something was wrong in
2667 your logic, or you need to put a conditional in to guard against
2670 =item Illegal hexadecimal digit %s ignored
2672 (W digit) You may have tried to use a character other than 0 - 9 or
2673 A - F, a - f in a hexadecimal number. Interpretation of the hexadecimal
2674 number stopped before the illegal character.
2676 =item Illegal modulus zero
2678 (F) You tried to divide a number by 0 to get the remainder. Most
2679 numbers don't take to this kindly.
2681 =item Illegal number of bits in vec
2683 (F) The number of bits in vec() (the third argument) must be a power of
2684 two from 1 to 32 (or 64, if your platform supports that).
2686 =item Illegal octal digit %s
2688 (F) You used an 8 or 9 in an octal number.
2690 =item Illegal octal digit %s ignored
2692 (W digit) You may have tried to use an 8 or 9 in an octal number.
2693 Interpretation of the octal number stopped before the 8 or 9.
2695 =item Illegal pattern in regex; marked by S<<-- HERE> in m/%s/
2697 (F) You wrote something like
2701 The C<"+"> is valid only when followed by digits, indicating a
2702 capturing group. See
2703 L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>.
2705 =item Illegal suidscript
2707 (F) The script run under suidperl was somehow illegal.
2709 =item Illegal switch in PERL5OPT: -%c
2711 (X) The PERL5OPT environment variable may only be used to set the
2712 following switches: B<-[CDIMUdmtw]>.
2714 =item Illegal user-defined property name
2716 (F) You specified a Unicode-like property name in a regular expression
2717 pattern (using C<\p{}> or C<\P{}>) that Perl knows isn't an official
2718 Unicode property, and was likely meant to be a user-defined property
2719 name, but it can't be one of those, as they must begin with either C<In>
2720 or C<Is>. Check the spelling. See also
2721 L</Can't find Unicode property definition "%s">.
2723 =item Ill-formed CRTL environ value "%s"
2725 (W internal) A warning peculiar to VMS. Perl tried to read the CRTL's
2726 internal environ array, and encountered an element without the C<=>
2727 delimiter used to separate keys from values. The element is ignored.
2729 =item Ill-formed message in prime_env_iter: |%s|
2731 (W internal) A warning peculiar to VMS. Perl tried to read a logical
2732 name or CLI symbol definition when preparing to iterate over %ENV, and
2733 didn't see the expected delimiter between key and value, so the line was
2736 =item (in cleanup) %s
2738 (W misc) This prefix usually indicates that a DESTROY() method raised
2739 the indicated exception. Since destructors are usually called by the
2740 system at arbitrary points during execution, and often a vast number of
2741 times, the warning is issued only once for any number of failures that
2742 would otherwise result in the same message being repeated.
2744 Failure of user callbacks dispatched using the C<G_KEEPERR> flag could
2745 also result in this warning. See L<perlcall/G_KEEPERR>.
2747 =item Incomplete expression within '(?[ ])' in regex; marked by S<<-- HERE>
2750 (F) There was a syntax error within the C<(?[ ])>. This can happen if the
2751 expression inside the construct was completely empty, or if there are
2752 too many or few operands for the number of operators. Perl is not smart
2753 enough to give you a more precise indication as to what is wrong.
2755 =item Inconsistent hierarchy during C3 merge of class '%s': merging failed on
2758 (F) The method resolution order (MRO) of the given class is not
2759 C3-consistent, and you have enabled the C3 MRO for this class. See the C3
2760 documentation in L<mro> for more information.
2762 =item Indentation on line %d of here-doc doesn't match delimiter
2764 (F) You have an indented here-document where one or more of its lines
2765 have whitespace at the beginning that does not match the closing
2768 For example, line 2 below is wrong because it does not have at least
2769 2 spaces, but lines 1 and 3 are fine because they have at least 2:
2779 Note that tabs and spaces are compared strictly, meaning 1 tab will
2782 =item Infinite recursion in regex
2784 (F) You used a pattern that references itself without consuming any input
2785 text. You should check the pattern to ensure that recursive patterns
2786 either consume text or fail.
2788 =item Initialization of state variables in list context currently forbidden
2790 (F) C<state> only permits initializing a single scalar variable, in scalar
2791 context. So C<state $a = 42> is allowed, but not C<state ($a) = 42>. To apply
2792 state semantics to a hash or array, store a hash or array reference in a
2795 =item %%s[%s] in scalar context better written as $%s[%s]
2797 (W syntax) In scalar context, you've used an array index/value slice
2798 (indicated by %) to select a single element of an array. Generally
2799 it's better to ask for a scalar value (indicated by $). The difference
2800 is that C<$foo[&bar]> always behaves like a scalar, both in the value it
2801 returns and when evaluating its argument, while C<%foo[&bar]> provides
2802 a list context to its subscript, which can do weird things if you're
2803 expecting only one subscript. When called in list context, it also
2804 returns the index (what C<&bar> returns) in addition to the value.
2806 =item %%s{%s} in scalar context better written as $%s{%s}
2808 (W syntax) In scalar context, you've used a hash key/value slice
2809 (indicated by %) to select a single element of a hash. Generally it's
2810 better to ask for a scalar value (indicated by $). The difference
2811 is that C<$foo{&bar}> always behaves like a scalar, both in the value
2812 it returns and when evaluating its argument, while C<@foo{&bar}> and
2813 provides a list context to its subscript, which can do weird things
2814 if you're expecting only one subscript. When called in list context,
2815 it also returns the key in addition to the value.
2817 =item Insecure dependency in %s
2819 (F) You tried to do something that the tainting mechanism didn't like.
2820 The tainting mechanism is turned on when you're running setuid or
2821 setgid, or when you specify B<-T> to turn it on explicitly. The
2822 tainting mechanism labels all data that's derived directly or indirectly
2823 from the user, who is considered to be unworthy of your trust. If any
2824 such data is used in a "dangerous" operation, you get this error. See
2825 L<perlsec> for more information.
2827 =item Insecure directory in %s
2829 (F) You can't use system(), exec(), or a piped open in a setuid or
2830 setgid script if C<$ENV{PATH}> contains a directory that is writable by
2831 the world. Also, the PATH must not contain any relative directory.
2834 =item Insecure $ENV{%s} while running %s
2836 (F) You can't use system(), exec(), or a piped open in a setuid or
2837 setgid script if any of C<$ENV{PATH}>, C<$ENV{IFS}>, C<$ENV{CDPATH}>,
2838 C<$ENV{ENV}>, C<$ENV{BASH_ENV}> or C<$ENV{TERM}> are derived from data
2839 supplied (or potentially supplied) by the user. The script must set
2840 the path to a known value, using trustworthy data. See L<perlsec>.
2842 =item Insecure user-defined property %s
2844 (F) Perl detected tainted data when trying to compile a regular
2845 expression that contains a call to a user-defined character property
2846 function, i.e. C<\p{IsFoo}> or C<\p{InFoo}>.
2847 See L<perlunicode/User-Defined Character Properties> and L<perlsec>.
2849 =item Integer overflow in format string for %s
2851 (F) The indexes and widths specified in the format string of C<printf()>
2852 or C<sprintf()> are too large. The numbers must not overflow the size of
2853 integers for your architecture.
2855 =item Integer overflow in %s number
2857 (S overflow) The hexadecimal, octal or binary number you have specified
2858 either as a literal or as an argument to hex() or oct() is too big for
2859 your architecture, and has been converted to a floating point number.
2860 On a 32-bit architecture the largest hexadecimal, octal or binary number
2861 representable without overflow is 0xFFFFFFFF, 037777777777, or
2862 0b11111111111111111111111111111111 respectively. Note that Perl
2863 transparently promotes all numbers to a floating point representation
2864 internally--subject to loss of precision errors in subsequent
2867 =item Integer overflow in srand
2869 (S overflow) The number you have passed to srand is too big to fit
2870 in your architecture's integer representation. The number has been
2871 replaced with the largest integer supported (0xFFFFFFFF on 32-bit
2872 architectures). This means you may be getting less randomness than
2873 you expect, because different random seeds above the maximum will
2874 return the same sequence of random numbers.
2876 =item Integer overflow in version
2878 =item Integer overflow in version %d
2880 (W overflow) Some portion of a version initialization is too large for
2881 the size of integers for your architecture. This is not a warning
2882 because there is no rational reason for a version to try and use an
2883 element larger than typically 2**32. This is usually caused by trying
2884 to use some odd mathematical operation as a version, like 100/9.
2886 =item Internal disaster in regex; marked by S<<-- HERE> in m/%s/
2888 (P) Something went badly wrong in the regular expression parser.
2889 The S<<-- HERE> shows whereabouts in the regular expression the problem was
2892 =item Internal inconsistency in tracking vforks
2894 (S) A warning peculiar to VMS. Perl keeps track of the number of times
2895 you've called C<fork> and C<exec>, to determine whether the current call
2896 to C<exec> should affect the current script or a subprocess (see
2897 L<perlvms/"exec LIST">). Somehow, this count has become scrambled, so
2898 Perl is making a guess and treating this C<exec> as a request to
2899 terminate the Perl script and execute the specified command.
2901 =item internal %<num>p might conflict with future printf extensions
2903 (S internal) Perl's internal routine that handles C<printf> and C<sprintf>
2904 formatting follows a slightly different set of rules when called from
2905 C or XS code. Specifically, formats consisting of digits followed
2906 by "p" (e.g., "%7p") are reserved for future use. If you see this
2907 message, then an XS module tried to call that routine with one such
2910 =item Internal urp in regex; marked by S<<-- HERE> in m/%s/
2912 (P) Something went badly awry in the regular expression parser. The
2913 S<<-- HERE> shows whereabouts in the regular expression the problem was
2916 =item %s (...) interpreted as function
2918 (W syntax) You've run afoul of the rule that says that any list operator
2919 followed by parentheses turns into a function, with all the list
2920 operators arguments found inside the parentheses. See
2921 L<perlop/Terms and List Operators (Leftward)>.
2923 =item In '(?...)', the '(' and '?' must be adjacent in regex;
2924 marked by S<<-- HERE> in m/%s/
2926 (F) The two-character sequence C<"(?"> in this context in a regular
2927 expression pattern should be an indivisible token, with nothing
2928 intervening between the C<"("> and the C<"?">, but you separated them
2931 =item Invalid %s attribute: %s
2933 (F) The indicated attribute for a subroutine or variable was not recognized
2934 by Perl or by a user-supplied handler. See L<attributes>.
2936 =item Invalid %s attributes: %s
2938 (F) The indicated attributes for a subroutine or variable were not
2939 recognized by Perl or by a user-supplied handler. See L<attributes>.
2941 =item Invalid character in charnames alias definition; marked by
2944 (F) You tried to create a custom alias for a character name, with
2945 the C<:alias> option to C<use charnames> and the specified character in
2946 the indicated name isn't valid. See L<charnames/CUSTOM ALIASES>.
2948 =item Invalid \0 character in %s for %s: %s\0%s
2950 (W syscalls) Embedded \0 characters in pathnames or other system call
2951 arguments produce a warning as of 5.20. The parts after the \0 were
2952 formerly ignored by system calls.
2954 =item Invalid character in \N{...}; marked by S<<-- HERE> in \N{%s}
2956 (F) Only certain characters are valid for character names. The
2957 indicated one isn't. See L<charnames/CUSTOM ALIASES>.
2959 =item Invalid conversion in %s: "%s"
2961 (W printf) Perl does not understand the given format conversion. See
2962 L<perlfunc/sprintf>.
2964 =item Invalid escape in the specified encoding in regex; marked by
2965 S<<-- HERE> in m/%s/
2967 (W regexp)(F) The numeric escape (for example C<\xHH>) of value < 256
2968 didn't correspond to a single character through the conversion
2969 from the encoding specified by the encoding pragma.
2970 The escape was replaced with REPLACEMENT CHARACTER (U+FFFD)
2971 instead, except within S<C<(?[ ])>>, where it is a fatal error.
2972 The S<<-- HERE> shows whereabouts in the regular expression the
2973 escape was discovered.
2975 =item Invalid hexadecimal number in \N{U+...}
2977 =item Invalid hexadecimal number in \N{U+...} in regex; marked by
2978 S<<-- HERE> in m/%s/
2980 (F) The character constant represented by C<...> is not a valid hexadecimal
2981 number. Either it is empty, or you tried to use a character other than
2982 0 - 9 or A - F, a - f in a hexadecimal number.
2984 =item Invalid module name %s with -%c option: contains single ':'
2986 (F) The module argument to perl's B<-m> and B<-M> command-line options
2987 cannot contain single colons in the module name, but only in the
2988 arguments after "=". In other words, B<-MFoo::Bar=:baz> is ok, but
2989 B<-MFoo:Bar=baz> is not.
2991 =item Invalid mro name: '%s'
2993 (F) You tried to C<mro::set_mro("classname", "foo")> or C<use mro 'foo'>,
2994 where C<foo> is not a valid method resolution order (MRO). Currently,
2995 the only valid ones supported are C<dfs> and C<c3>, unless you have loaded
2996 a module that is a MRO plugin. See L<mro> and L<perlmroapi>.
2998 =item Invalid negative number (%s) in chr
3000 (W utf8) You passed a negative number to C<chr>. Negative numbers are
3001 not valid character numbers, so it returns the Unicode replacement
3004 =item Invalid number '%s' for -C option.
3006 (F) You supplied a number to the -C option that either has extra leading
3007 zeroes or overflows perl's unsigned integer representation.
3009 =item invalid option -D%c, use -D'' to see choices
3011 (S debugging) Perl was called with invalid debugger flags. Call perl
3012 with the B<-D> option with no flags to see the list of acceptable values.
3013 See also L<perlrun/-Dletters>.
3015 =item Invalid quantifier in {,} in regex; marked by S<<-- HERE> in m/%s/
3017 (F) The pattern looks like a {min,max} quantifier, but the min or max
3018 could not be parsed as a valid number - either it has leading zeroes,
3019 or it represents too big a number to cope with. The S<<-- HERE> shows
3020 where in the regular expression the problem was discovered. See L<perlre>.
3022 =item Invalid [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
3024 (F) The range specified in a character class had a minimum character
3025 greater than the maximum character. One possibility is that you forgot the
3026 C<{}> from your ending C<\x{}> - C<\x> without the curly braces can go only
3027 up to C<ff>. The S<<-- HERE> shows whereabouts in the regular expression the
3028 problem was discovered. See L<perlre>.
3030 =item Invalid range "%s" in transliteration operator
3032 (F) The range specified in the tr/// or y/// operator had a minimum
3033 character greater than the maximum character. See L<perlop>.
3035 =item Invalid separator character %s in attribute list
3037 (F) Something other than a colon or whitespace was seen between the
3038 elements of an attribute list. If the previous attribute had a
3039 parenthesised parameter list, perhaps that list was terminated too soon.
3042 =item Invalid separator character %s in PerlIO layer specification %s
3044 (W layer) When pushing layers onto the Perl I/O system, something other
3045 than a colon or whitespace was seen between the elements of a layer list.
3046 If the previous attribute had a parenthesised parameter list, perhaps that
3047 list was terminated too soon.
3049 =item Invalid strict version format (%s)
3051 (F) A version number did not meet the "strict" criteria for versions.
3052 A "strict" version number is a positive decimal number (integer or
3053 decimal-fraction) without exponentiation or else a dotted-decimal
3054 v-string with a leading 'v' character and at least three components.
3055 The parenthesized text indicates which criteria were not met.
3056 See the L<version> module for more details on allowed version formats.
3058 =item Invalid type '%s' in %s
3060 (F) The given character is not a valid pack or unpack type.
3061 See L<perlfunc/pack>.
3063 (W) The given character is not a valid pack or unpack type but used to be
3066 =item Invalid version format (%s)
3068 (F) A version number did not meet the "lax" criteria for versions.
3069 A "lax" version number is a positive decimal number (integer or
3070 decimal-fraction) without exponentiation or else a dotted-decimal
3071 v-string. If the v-string has fewer than three components, it
3072 must have a leading 'v' character. Otherwise, the leading 'v' is
3073 optional. Both decimal and dotted-decimal versions may have a
3074 trailing "alpha" component separated by an underscore character
3075 after a fractional or dotted-decimal component. The parenthesized
3076 text indicates which criteria were not met. See the L<version> module
3077 for more details on allowed version formats.
3079 =item Invalid version object
3081 (F) The internal structure of the version object was invalid.
3082 Perhaps the internals were modified directly in some way or
3083 an arbitrary reference was blessed into the "version" class.
3085 =item In '(*VERB...)', the '(' and '*' must be adjacent in regex;
3086 marked by S<<-- HERE> in m/%s/
3088 (F) The two-character sequence C<"(*"> in
3089 this context in a regular expression pattern should be an
3090 indivisible token, with nothing intervening between the C<"(">
3091 and the C<"*">, but you separated them.
3093 =item ioctl is not implemented
3095 (F) Your machine apparently doesn't implement ioctl(), which is pretty
3096 strange for a machine that supports C.
3098 =item ioctl() on unopened %s
3100 (W unopened) You tried ioctl() on a filehandle that was never opened.
3101 Check your control flow and number of arguments.
3103 =item IO layers (like '%s') unavailable
3105 (F) Your Perl has not been configured to have PerlIO, and therefore
3106 you cannot use IO layers. To have PerlIO, Perl must be configured
3109 =item IO::Socket::atmark not implemented on this architecture
3111 (F) Your machine doesn't implement the sockatmark() functionality,
3112 neither as a system call nor an ioctl call (SIOCATMARK).
3114 =item '%s' is an unknown bound type in regex; marked by S<<-- HERE> in m/%s/
3116 (F) You used C<\b{...}> or C<\B{...}> and the C<...> is not known to
3117 Perl. The current valid ones are given in
3118 L<perlrebackslash/\b{}, \b, \B{}, \B>.
3120 =item %s() is deprecated on :utf8 handles. This will be a fatal error in Perl 5.30
3122 (D deprecated) The sysread(), recv(), syswrite() and send() operators are
3123 deprecated on handles that have the C<:utf8> layer, either explicitly, or
3124 implicitly, eg., with the C<:encoding(UTF-16LE)> layer.
3126 Both sysread() and recv() currently use only the C<:utf8> flag for the stream,
3127 ignoring the actual layers. Since sysread() and recv() do no UTF-8
3128 validation they can end up creating invalidly encoded scalars.
3130 Similarly, syswrite() and send() use only the C<:utf8> flag, otherwise ignoring
3131 any layers. If the flag is set, both write the value UTF-8 encoded, even if
3132 the layer is some different encoding, such as the example above.
3134 Ideally, all of these operators would completely ignore the C<:utf8> state,
3135 working only with bytes, but this would result in silently breaking existing
3138 In Perl 5.30, it will no longer be possible to use sysread(), recv(),
3139 syswrite() or send() to read or send bytes from/to :utf8 handles.
3141 =item "%s" is more clearly written simply as "%s" in regex; marked by S<<-- HERE> in m/%s/
3143 (W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
3145 You specified a character that has the given plainer way of writing it,
3146 and which is also portable to platforms running with different character
3149 =item $* is no longer supported. Its use will be fatal in Perl 5.30
3151 (D deprecated, syntax) The special variable C<$*>, deprecated in older
3152 perls, has been removed as of 5.10.0 and is no longer supported. In
3153 previous versions of perl the use of C<$*> enabled or disabled multi-line
3154 matching within a string.
3156 Instead of using C<$*> you should use the C</m> (and maybe C</s>) regexp
3157 modifiers. You can enable C</m> for a lexical scope (even a whole file)
3158 with C<use re '/m'>. (In older versions: when C<$*> was set to a true value
3159 then all regular expressions behaved as if they were written using C</m>.)
3161 Use of this variable will be a fatal error in Perl 5.30.
3163 =item $# is no longer supported. Its use will be fatal in Perl 5.30
3165 (D deprecated, syntax) The special variable C<$#>, deprecated in older
3166 perls, has been removed as of 5.10.0 and is no longer supported. You
3167 should use the printf/sprintf functions instead.
3169 Use of this variable will be a fatal error in Perl 5.30.
3171 =item '%s' is not a code reference
3173 (W overload) The second (fourth, sixth, ...) argument of
3174 overload::constant needs to be a code reference. Either
3175 an anonymous subroutine, or a reference to a subroutine.
3177 =item '%s' is not an overloadable type
3179 (W overload) You tried to overload a constant type the overload package is
3182 =item -i used with no filenames on the command line, reading from STDIN
3184 (S inplace) The C<-i> option was passed on the command line, indicating
3185 that the script is intended to edit files in place, but no files were
3186 given. This is usually a mistake, since editing STDIN in place doesn't
3187 make sense, and can be confusing because it can make perl look like
3188 it is hanging when it is really just trying to read from STDIN. You
3189 should either pass a filename to edit, or remove C<-i> from the command
3190 line. See L<perlrun> for more details.
3192 =item Junk on end of regexp in regex m/%s/
3194 (P) The regular expression parser is confused.
3196 =item Label not found for "last %s"
3198 (F) You named a loop to break out of, but you're not currently in a loop
3199 of that name, not even if you count where you were called from. See
3202 =item Label not found for "next %s"
3204 (F) You named a loop to continue, but you're not currently in a loop of
3205 that name, not even if you count where you were called from. See
3208 =item Label not found for "redo %s"
3210 (F) You named a loop to restart, but you're not currently in a loop of
3211 that name, not even if you count where you were called from. See
3214 =item leaving effective %s failed
3216 (F) While under the C<use filetest> pragma, switching the real and
3217 effective uids or gids failed.
3219 =item length/code after end of string in unpack
3221 (F) While unpacking, the string buffer was already used up when an unpack
3222 length/code combination tried to obtain more data. This results in
3223 an undefined value for the length. See L<perlfunc/pack>.
3225 =item length() used on %s (did you mean "scalar(%s)"?)
3227 (W syntax) You used length() on either an array or a hash when you
3228 probably wanted a count of the items.
3230 Array size can be obtained by doing:
3234 The number of items in a hash can be obtained by doing:
3238 =item Lexing code attempted to stuff non-Latin-1 character into Latin-1 input
3240 (F) An extension is attempting to insert text into the current parse
3241 (using L<lex_stuff_pvn|perlapi/lex_stuff_pvn> or similar), but tried to insert a character that
3242 couldn't be part of the current input. This is an inherent pitfall
3243 of the stuffing mechanism, and one of the reasons to avoid it. Where
3244 it is necessary to stuff, stuffing only plain ASCII is recommended.
3246 =item Lexing code internal error (%s)
3248 (F) Lexing code supplied by an extension violated the lexer's API in a
3251 =item listen() on closed socket %s
3253 (W closed) You tried to do a listen on a closed socket. Did you forget
3254 to check the return value of your socket() call? See
3257 =item List form of piped open not implemented
3259 (F) On some platforms, notably Windows, the three-or-more-arguments
3260 form of C<open> does not support pipes, such as C<open($pipe, '|-', @args)>.
3261 Use the two-argument C<open($pipe, '|prog arg1 arg2...')> form instead.
3263 =item %s: loadable library and perl binaries are mismatched (got handshake key %p, needed %p)
3265 (P) A dynamic loading library C<.so> or C<.dll> was being loaded into the
3266 process that was built against a different build of perl than the
3267 said library was compiled against. Reinstalling the XS module will
3268 likely fix this error.
3270 =item Locale '%s' may not work well.%s
3272 (W locale) You are using the named locale, which is a non-UTF-8 one, and
3273 which perl has determined is not fully compatible with what it can
3274 handle. The second C<%s> gives a reason.
3276 By far the most common reason is that the locale has characters in it
3277 that are represented by more than one byte. The only such locales that
3278 Perl can handle are the UTF-8 locales. Most likely the specified locale
3279 is a non-UTF-8 one for an East Asian language such as Chinese or
3280 Japanese. If the locale is a superset of ASCII, the ASCII portion of it
3283 Some essentially obsolete locales that aren't supersets of ASCII, mainly
3284 those in ISO 646 or other 7-bit locales, such as ASMO 449, can also have
3285 problems, depending on what portions of the ASCII character set get
3286 changed by the locale and are also used by the program.
3287 The warning message lists the determinable conflicting characters.
3289 Note that not all incompatibilities are found.
3291 If this happens to you, there's not much you can do except switch to use a
3292 different locale or use L<Encode> to translate from the locale into
3293 UTF-8; if that's impracticable, you have been warned that some things
3296 This message is output once each time a bad locale is switched into
3297 within the scope of C<S<use locale>>, or on the first possibly-affected
3298 operation if the C<S<use locale>> inherits a bad one. It is not raised
3299 for any operations from the L<POSIX> module.
3301 =item localtime(%f) failed
3303 (W overflow) You called C<localtime> with a number that it could not handle:
3304 too large, too small, or NaN. The returned value is C<undef>.
3306 =item localtime(%f) too large
3308 (W overflow) You called C<localtime> with a number that was larger
3309 than it can reliably handle and C<localtime> probably returned the
3310 wrong date. This warning is also triggered with NaN (the special
3311 not-a-number value).
3313 =item localtime(%f) too small
3315 (W overflow) You called C<localtime> with a number that was smaller
3316 than it can reliably handle and C<localtime> probably returned the
3319 =item Lookbehind longer than %d not implemented in regex m/%s/
3321 (F) There is currently a limit on the length of string which lookbehind can
3322 handle. This restriction may be eased in a future release.
3324 =item Lost precision when %s %f by 1
3326 (W imprecision) The value you attempted to increment or decrement by one
3327 is too large for the underlying floating point representation to store
3328 accurately, hence the target of C<++> or C<--> is unchanged. Perl issues this
3329 warning because it has already switched from integers to floating point
3330 when values are too large for integers, and now even floating point is
3331 insufficient. You may wish to switch to using L<Math::BigInt> explicitly.
3333 =item lstat() on filehandle%s
3335 (W io) You tried to do an lstat on a filehandle. What did you mean
3336 by that? lstat() makes sense only on filenames. (Perl did a fstat()
3337 instead on the filehandle.)
3339 =item lvalue attribute %s already-defined subroutine
3341 (W misc) Although L<attributes.pm|attributes> allows this, turning the lvalue
3342 attribute on or off on a Perl subroutine that is already defined
3343 does not always work properly. It may or may not do what you
3344 want, depending on what code is inside the subroutine, with exact
3345 details subject to change between Perl versions. Only do this
3346 if you really know what you are doing.
3348 =item lvalue attribute ignored after the subroutine has been defined
3350 (W misc) Using the C<:lvalue> declarative syntax to make a Perl
3351 subroutine an lvalue subroutine after it has been defined is
3352 not permitted. To make the subroutine an lvalue subroutine,
3353 add the lvalue attribute to the definition, or put the C<sub
3354 foo :lvalue;> declaration before the definition.
3356 See also L<attributes.pm|attributes>.
3358 =item Magical list constants are not supported
3360 (F) You assigned a magical array to a stash element, and then tried
3361 to use the subroutine from the same slot. You are asking Perl to do
3362 something it cannot do, details subject to change between Perl versions.
3364 =item Malformed integer in [] in pack
3366 (F) Between the brackets enclosing a numeric repeat count only digits
3367 are permitted. See L<perlfunc/pack>.
3369 =item Malformed integer in [] in unpack
3371 (F) Between the brackets enclosing a numeric repeat count only digits
3372 are permitted. See L<perlfunc/pack>.
3374 =item Malformed PERLLIB_PREFIX
3376 (F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form
3383 with nonempty prefix1 and prefix2. If C<prefix1> is indeed a prefix of
3384 a builtin library search path, prefix2 is substituted. The error may
3385 appear if components are not found, or are too long. See
3386 "PERLLIB_PREFIX" in L<perlos2>.
3388 =item Malformed prototype for %s: %s
3390 (F) You tried to use a function with a malformed prototype. The
3391 syntax of function prototypes is given a brief compile-time check for
3392 obvious errors like invalid characters. A more rigorous check is run
3393 when the function is called.
3394 Perhaps the function's author was trying to write a subroutine signature
3395 but didn't enable that feature first (C<use feature 'signatures'>),
3396 so the signature was instead interpreted as a bad prototype.
3398 =item Malformed UTF-8 character%s
3400 (S utf8)(F) Perl detected a string that should be UTF-8, but didn't
3401 comply with UTF-8 encoding rules, or represents a code point whose
3402 ordinal integer value doesn't fit into the word size of the current
3403 platform (overflows). Details as to the exact malformation are given in
3404 the variable, C<%s>, part of the message.
3406 One possible cause is that you set the UTF8 flag yourself for data that
3407 you thought to be in UTF-8 but it wasn't (it was for example legacy
3408 8-bit data). To guard against this, you can use C<Encode::decode('UTF-8', ...)>.
3410 If you use the C<:encoding(UTF-8)> PerlIO layer for input, invalid byte
3411 sequences are handled gracefully, but if you use C<:utf8>, the flag is
3412 set without validating the data, possibly resulting in this error
3415 See also L<Encode/"Handling Malformed Data">.
3417 =item Malformed UTF-8 character immediately after '%s'
3419 (F) You said C<use utf8>, but the program file doesn't comply with UTF-8
3420 encoding rules. The message prints out the properly encoded characters
3421 just before the first bad one. If C<utf8> warnings are enabled, a
3422 warning is generated that gives more details about the type of
3425 =item Malformed UTF-8 returned by \N{%s} immediately after '%s'
3427 (F) The charnames handler returned malformed UTF-8.
3429 =item Malformed UTF-8 string in '%c' format in unpack
3431 (F) You tried to unpack something that didn't comply with UTF-8 encoding
3432 rules and perl was unable to guess how to make more progress.
3434 =item Malformed UTF-8 string in pack
3436 (F) You tried to pack something that didn't comply with UTF-8 encoding
3437 rules and perl was unable to guess how to make more progress.
3439 =item Malformed UTF-8 string in unpack
3441 (F) You tried to unpack something that didn't comply with UTF-8 encoding
3442 rules and perl was unable to guess how to make more progress.
3444 =item Malformed UTF-8 string in "%s"
3446 (F) This message indicates a bug either in the Perl core or in XS
3447 code. Such code was trying to find out if a character, allegedly
3448 stored internally encoded as UTF-8, was of a given type, such as
3449 being punctuation or a digit. But the character was not encoded
3450 in legal UTF-8. The C<%s> is replaced by a string that can be used
3451 by knowledgeable people to determine what the type being checked
3454 Passing malformed strings was deprecated in Perl 5.18, and
3455 became fatal in Perl 5.26.
3457 =item Malformed UTF-16 surrogate
3459 (F) Perl thought it was reading UTF-16 encoded character data but while
3460 doing it Perl met a malformed Unicode surrogate.
3462 =item Mandatory parameter follows optional parameter
3464 (F) In a subroutine signature, you wrote something like "$a = undef,
3465 $b", making an earlier parameter optional and a later one mandatory.
3466 Parameters are filled from left to right, so it's impossible for the
3467 caller to omit an earlier one and pass a later one. If you want to act
3468 as if the parameters are filled from right to left, declare the rightmost
3469 optional and then shuffle the parameters around in the subroutine's body.
3471 =item Matched non-Unicode code point 0x%X against Unicode property; may
3474 (S non_unicode) Perl allows strings to contain a superset of
3475 Unicode code points; each code point may be as large as what is storable
3476 in an unsigned integer on your system, but these may not be accepted by
3477 other languages/systems. This message occurs when you matched a string
3478 containing such a code point against a regular expression pattern, and
3479 the code point was matched against a Unicode property, C<\p{...}> or
3480 C<\P{...}>. Unicode properties are only defined on Unicode code points,
3481 so the result of this match is undefined by Unicode, but Perl (starting
3482 in v5.20) treats non-Unicode code points as if they were typical
3483 unassigned Unicode ones, and matched this one accordingly. Whether a
3484 given property matches these code points or not is specified in
3485 L<perluniprops/Properties accessible through \p{} and \P{}>.
3487 This message is suppressed (unless it has been made fatal) if it is
3488 immaterial to the results of the match if the code point is Unicode or
3489 not. For example, the property C<\p{ASCII_Hex_Digit}> only can match
3490 the 22 characters C<[0-9A-Fa-f]>, so obviously all other code points,
3491 Unicode or not, won't match it. (And C<\P{ASCII_Hex_Digit}> will match
3492 every code point except these 22.)
3494 Getting this message indicates that the outcome of the match arguably
3495 should have been the opposite of what actually happened. If you think
3496 that is the case, you may wish to make the C<non_unicode> warnings
3497 category fatal; if you agree with Perl's decision, you may wish to turn
3500 See L<perlunicode/Beyond Unicode code points> for more information.
3502 =item %s matches null string many times in regex; marked by S<<-- HERE> in
3505 (W regexp) The pattern you've specified would be an infinite loop if the
3506 regular expression engine didn't specifically check for that. The S<<-- HERE>
3507 shows whereabouts in the regular expression the problem was discovered.
3510 =item Maximal count of pending signals (%u) exceeded
3512 (F) Perl aborted due to too high a number of signals pending. This
3513 usually indicates that your operating system tried to deliver signals
3514 too fast (with a very high priority), starving the perl process from
3515 resources it would need to reach a point where it can process signals
3516 safely. (See L<perlipc/"Deferred Signals (Safe Signals)">.)
3518 =item "%s" may clash with future reserved word
3520 (W) This warning may be due to running a perl5 script through a perl4
3521 interpreter, especially if the word that is being warned about is
3524 =item '%' may not be used in pack
3526 (F) You can't pack a string by supplying a checksum, because the
3527 checksumming process loses information, and you can't go the other way.
3528 See L<perlfunc/unpack>.
3530 =item Method for operation %s not found in package %s during blessing
3532 (F) An attempt was made to specify an entry in an overloading table that
3533 doesn't resolve to a valid subroutine. See L<overload>.
3535 =item Method %s not permitted
3537 See L</500 Server error>.
3539 =item Might be a runaway multi-line %s string starting on line %d
3541 (S) An advisory indicating that the previous error may have been caused
3542 by a missing delimiter on a string or pattern, because it eventually
3543 ended earlier on the current line.
3545 =item Misplaced _ in number
3547 (W syntax) An underscore (underbar) in a numeric constant did not
3548 separate two digits.
3550 =item Missing argument in %s
3552 (W missing) You called a function with fewer arguments than other
3553 arguments you supplied indicated would be needed.
3555 Currently only emitted when a printf-type format required more
3556 arguments than were supplied, but might be used in the future for
3557 other cases where we can statically determine that arguments to
3558 functions are missing, e.g. for the L<perlfunc/pack> function.
3560 =item Missing argument to -%c
3562 (F) The argument to the indicated command line switch must follow
3563 immediately after the switch, without intervening spaces.
3565 =item Missing braces on \N{}
3567 =item Missing braces on \N{} in regex; marked by S<<-- HERE> in m/%s/
3569 (F) Wrong syntax of character name literal C<\N{charname}> within
3570 double-quotish context. This can also happen when there is a space
3571 (or comment) between the C<\N> and the C<{> in a regex with the C</x> modifier.
3572 This modifier does not change the requirement that the brace immediately
3575 =item Missing braces on \o{}
3577 (F) A C<\o> must be followed immediately by a C<{> in double-quotish context.
3579 =item Missing comma after first argument to %s function
3581 (F) While certain functions allow you to specify a filehandle or an
3582 "indirect object" before the argument list, this ain't one of them.
3584 =item Missing command in piped open
3586 (W pipe) You used the C<open(FH, "| command")> or
3587 C<open(FH, "command |")> construction, but the command was missing or
3590 =item Missing control char name in \c
3592 (F) A double-quoted string ended with "\c", without the required control
3595 =item Missing ']' in prototype for %s : %s
3597 (W illegalproto) A grouping was started with C<[> but never closed with C<]>.
3599 =item Missing name in "%s sub"
3601 (F) The syntax for lexically scoped subroutines requires that
3602 they have a name with which they can be found.
3604 =item Missing $ on loop variable
3606 (F) Apparently you've been programming in B<csh> too much. Variables
3607 are always mentioned with the $ in Perl, unlike in the shells, where it
3608 can vary from one line to the next.
3610 =item (Missing operator before %s?)
3612 (S syntax) This is an educated guess made in conjunction with the message
3613 "%s found where operator expected". Often the missing operator is a comma.
3615 =item Missing or undefined argument to %s
3617 (F) You tried to call require or do with no argument or with an undefined
3618 value as an argument. Require expects either a package name or a
3619 file-specification as an argument; do expects a filename. See
3620 L<perlfunc/require EXPR> and L<perlfunc/do EXPR>.
3622 =item Missing right brace on \%c{} in regex; marked by S<<-- HERE> in m/%s/
3624 (F) Missing right brace in C<\x{...}>, C<\p{...}>, C<\P{...}>, or C<\N{...}>.
3626 =item Missing right brace on \N{}
3628 =item Missing right brace on \N{} or unescaped left brace after \N
3630 (F) C<\N> has two meanings.
3632 The traditional one has it followed by a name enclosed in braces,
3633 meaning the character (or sequence of characters) given by that
3634 name. Thus C<\N{ASTERISK}> is another way of writing C<*>, valid in both
3635 double-quoted strings and regular expression patterns. In patterns,
3636 it doesn't have the meaning an unescaped C<*> does.
3638 Starting in Perl 5.12.0, C<\N> also can have an additional meaning (only)
3639 in patterns, namely to match a non-newline character. (This is short
3640 for C<[^\n]>, and like C<.> but is not affected by the C</s> regex modifier.)
3642 This can lead to some ambiguities. When C<\N> is not followed immediately
3643 by a left brace, Perl assumes the C<[^\n]> meaning. Also, if the braces
3644 form a valid quantifier such as C<\N{3}> or C<\N{5,}>, Perl assumes that this
3645 means to match the given quantity of non-newlines (in these examples,
3646 3; and 5 or more, respectively). In all other case, where there is a
3647 C<\N{> and a matching C<}>, Perl assumes that a character name is desired.
3649 However, if there is no matching C<}>, Perl doesn't know if it was
3650 mistakenly omitted, or if C<[^\n]{> was desired, and raises this error.
3651 If you meant the former, add the right brace; if you meant the latter,
3652 escape the brace with a backslash, like so: C<\N\{>
3654 =item Missing right curly or square bracket
3656 (F) The lexer counted more opening curly or square brackets than closing
3657 ones. As a general rule, you'll find it's missing near the place you
3660 =item (Missing semicolon on previous line?)
3662 (S syntax) This is an educated guess made in conjunction with the message
3663 "%s found where operator expected". Don't automatically put a semicolon on
3664 the previous line just because you saw this message.
3666 =item Modification of a read-only value attempted
3668 (F) You tried, directly or indirectly, to change the value of a
3669 constant. You didn't, of course, try "2 = 1", because the compiler
3670 catches that. But an easy way to do the same thing is:
3672 sub mod { $_[0] = 1 }
3675 Another way is to assign to a substr() that's off the end of the string.
3677 Yet another way is to assign to a C<foreach> loop I<VAR> when I<VAR>
3678 is aliased to a constant in the look I<LIST>:
3681 foreach my $n ($x, 2) {
3682 $n *= 2; # modifies the $x, but fails on attempt to
3685 =item Modification of non-creatable array value attempted, %s
3687 (F) You tried to make an array value spring into existence, and the
3688 subscript was probably negative, even counting from end of the array
3691 =item Modification of non-creatable hash value attempted, %s
3693 (P) You tried to make a hash value spring into existence, and it
3694 couldn't be created for some peculiar reason.
3696 =item Module name must be constant
3698 (F) Only a bare module name is allowed as the first argument to a "use".
3700 =item Module name required with -%c option
3702 (F) The C<-M> or C<-m> options say that Perl should load some module, but
3703 you omitted the name of the module. Consult L<perlrun> for full details
3704 about C<-M> and C<-m>.
3706 =item More than one argument to '%s' open
3708 (F) The C<open> function has been asked to open multiple files. This
3709 can happen if you are trying to open a pipe to a command that takes a
3710 list of arguments, but have forgotten to specify a piped open mode.
3711 See L<perlfunc/open> for details.
3713 =item mprotect for COW string %p %u failed with %d
3715 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_COW (see
3716 L<perlguts/"Copy on Write">), but a shared string buffer
3717 could not be made read-only.
3719 =item mprotect for %p %u failed with %d
3721 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_OPS (see L<perlhacktips>),
3722 but an op tree could not be made read-only.
3724 =item mprotect RW for COW string %p %u failed with %d
3726 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_COW (see
3727 L<perlguts/"Copy on Write">), but a read-only shared string
3728 buffer could not be made mutable.
3730 =item mprotect RW for %p %u failed with %d
3732 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_OPS (see
3733 L<perlhacktips>), but a read-only op tree could not be made
3734 mutable before freeing the ops.
3736 =item msg%s not implemented
3738 (F) You don't have System V message IPC on your system.
3740 =item Multidimensional syntax %s not supported
3742 (W syntax) Multidimensional arrays aren't written like C<$foo[1,2,3]>.
3743 They're written like C<$foo[1][2][3]>, as in C.
3745 =item Multiple slurpy parameters not allowed
3747 (F) In subroutine signatures, a slurpy parameter (C<@> or C<%>) must be
3748 the last parameter, and there must not be more than one of them; for
3751 sub foo ($a, @b) {} # legal
3752 sub foo ($a, @b, %) {} # invalid
3754 =item '/' must follow a numeric type in unpack
3756 (F) You had an unpack template that contained a '/', but this did not
3757 follow some unpack specification producing a numeric value.
3758 See L<perlfunc/pack>.
3760 =item %s must not be a named sequence in transliteration operator
3762 (F) Transliteration (C<tr///> and C<y///>) transliterates individual
3763 characters. But a named sequence by definition is more than an
3764 individual charater, and hence doing this operation on it doesn't make
3767 =item "my sub" not yet implemented
3769 (F) Lexically scoped subroutines are not yet implemented. Don't try
3772 =item "my" subroutine %s can't be in a package
3774 (F) Lexically scoped subroutines aren't in a package, so it doesn't make
3775 sense to try to declare one with a package qualifier on the front.
3777 =item "my %s" used in sort comparison
3779 (W syntax) The package variables $a and $b are used for sort comparisons.
3780 You used $a or $b in as an operand to the C<< <=> >> or C<cmp> operator inside a
3781 sort comparison block, and the variable had earlier been declared as a
3782 lexical variable. Either qualify the sort variable with the package
3783 name, or rename the lexical variable.
3785 =item "my" variable %s can't be in a package
3787 (F) Lexically scoped variables aren't in a package, so it doesn't make
3788 sense to try to declare one with a package qualifier on the front. Use
3789 local() if you want to localize a package variable.
3791 =item Name "%s::%s" used only once: possible typo
3793 (W once) Typographical errors often show up as unique variable
3794 names. If you had a good reason for having a unique name, then
3795 just mention it again somehow to suppress the message. The C<our>
3796 declaration is also provided for this purpose.
3798 NOTE: This warning detects package symbols that have been used
3799 only once. This means lexical variables will never trigger this
3800 warning. It also means that all of the package variables $c, @c,
3801 %c, as well as *c, &c, sub c{}, c(), and c (the filehandle or
3802 format) are considered the same; if a program uses $c only once
3803 but also uses any of the others it will not trigger this warning.
3804 Symbols beginning with an underscore and symbols using special
3805 identifiers (q.v. L<perldata>) are exempt from this warning.
3807 =item Need exactly 3 octal digits in regex; marked by S<<-- HERE> in m/%s/
3809 (F) Within S<C<(?[ ])>>, all constants interpreted as octal need to be
3810 exactly 3 digits long. This helps catch some ambiguities. If your
3811 constant is too short, add leading zeros, like
3813 (?[ [ \078 ] ]) # Syntax error!
3814 (?[ [ \0078 ] ]) # Works
3815 (?[ [ \007 8 ] ]) # Clearer
3817 The maximum number this construct can express is C<\777>. If you
3818 need a larger one, you need to use L<\o{}|perlrebackslash/Octal escapes> instead. If you meant
3819 two separate things, you need to separate them:
3821 (?[ [ \7776 ] ]) # Syntax error!
3822 (?[ [ \o{7776} ] ]) # One meaning
3823 (?[ [ \777 6 ] ]) # Another meaning
3824 (?[ [ \777 \006 ] ]) # Still another
3826 =item Negative '/' count in unpack
3828 (F) The length count obtained from a length/code unpack operation was
3829 negative. See L<perlfunc/pack>.
3831 =item Negative length
3833 (F) You tried to do a read/write/send/recv operation with a buffer
3834 length that is less than 0. This is difficult to imagine.
3836 =item Negative offset to vec in lvalue context
3838 (F) When C<vec> is called in an lvalue context, the second argument must be
3839 greater than or equal to zero.
3841 =item Negative repeat count does nothing
3843 (W numeric) You tried to execute the
3844 L<C<x>|perlop/Multiplicative Operators> repetition operator fewer than 0
3845 times, which doesn't make sense.
3847 =item Nested quantifiers in regex; marked by S<<-- HERE> in m/%s/
3849 (F) You can't quantify a quantifier without intervening parentheses.
3850 So things like ** or +* or ?* are illegal. The S<<-- HERE> shows
3851 whereabouts in the regular expression the problem was discovered.
3853 Note that the minimal matching quantifiers, C<*?>, C<+?>, and
3854 C<??> appear to be nested quantifiers, but aren't. See L<perlre>.
3856 =item %s never introduced
3858 (S internal) The symbol in question was declared but somehow went out of
3859 scope before it could possibly have been used.
3861 =item next::method/next::can/maybe::next::method cannot find enclosing method
3863 (F) C<next::method> needs to be called within the context of a
3864 real method in a real package, and it could not find such a context.
3867 =item \N in a character class must be a named character: \N{...} in regex;
3868 marked by S<<-- HERE> in m/%s/
3870 (F) The new (as of Perl 5.12) meaning of C<\N> as C<[^\n]> is not valid in a
3871 bracketed character class, for the same reason that C<.> in a character
3872 class loses its specialness: it matches almost everything, which is
3873 probably not what you want.
3875 =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/
3877 (F) Named Unicode character escapes (C<\N{...}>) may return a
3878 multi-character sequence. Even though a character class is
3879 supposed to match just one character of input, perl will match the
3880 whole thing correctly, except when the class is inverted (C<[^...]>),
3881 or the escape is the beginning or final end point of a range. The
3882 mathematically logical behavior for what matches when inverting
3883 is very different from what people expect, so we have decided to
3884 forbid it. Similarly unclear is what should be generated when the
3885 C<\N{...}> is used as one of the end points of the range, such as in
3887 [\x{41}-\N{ARABIC SEQUENCE YEH WITH HAMZA ABOVE WITH AE}]
3889 What is meant here is unclear, as the C<\N{...}> escape is a sequence
3890 of code points, so this is made an error.
3892 =item \N{NAME} must be resolved by the lexer in regex; marked by
3893 S<<-- HERE> in m/%s/
3895 (F) When compiling a regex pattern, an unresolved named character or
3896 sequence was encountered. This can happen in any of several ways that
3897 bypass the lexer, such as using single-quotish context, or an extra
3898 backslash in double-quotish:
3900 $re = '\N{SPACE}'; # Wrong!
3901 $re = "\\N{SPACE}"; # Wrong!
3904 Instead, use double-quotes with a single backslash:
3906 $re = "\N{SPACE}"; # ok
3909 The lexer can be bypassed as well by creating the pattern from smaller
3913 /${re}{SPACE}/; # Wrong!
3915 It's not a good idea to split a construct in the middle like this, and
3916 it doesn't work here. Instead use the solution above.
3918 Finally, the message also can happen under the C</x> regex modifier when the
3919 C<\N> is separated by spaces from the C<{>, in which case, remove the spaces.
3921 /\N {SPACE}/x; # Wrong!
3924 =item No %s allowed while running setuid
3926 (F) Certain operations are deemed to be too insecure for a setuid or
3927 setgid script to even be allowed to attempt. Generally speaking there
3928 will be another way to do what you want that is, if not secure, at least
3929 securable. See L<perlsec>.
3931 =item No code specified for -%c
3933 (F) Perl's B<-e> and B<-E> command-line options require an argument. If
3934 you want to run an empty program, pass the empty string as a separate
3935 argument or run a program consisting of a single 0 or 1:
3941 =item No comma allowed after %s
3943 (F) A list operator that has a filehandle or "indirect object" is
3944 not allowed to have a comma between that and the following arguments.
3945 Otherwise it'd be just another one of the arguments.
3947 One possible cause for this is that you expected to have imported
3948 a constant to your name space with B<use> or B<import> while no such
3949 importing took place, it may for example be that your operating
3950 system does not support that particular constant. Hopefully you did
3951 use an explicit import list for the constants you expect to see;
3952 please see L<perlfunc/use> and L<perlfunc/import>. While an
3953 explicit import list would probably have caught this error earlier
3954 it naturally does not remedy the fact that your operating system
3955 still does not support that constant. Maybe you have a typo in
3956 the constants of the symbol import list of B<use> or B<import> or in the
3957 constant name at the line where this error was triggered?
3959 =item No command into which to pipe on command line
3961 (F) An error peculiar to VMS. Perl handles its own command line
3962 redirection, and found a '|' at the end of the command line, so it
3963 doesn't know where you want to pipe the output from this command.
3965 =item No DB::DB routine defined
3967 (F) The currently executing code was compiled with the B<-d> switch, but
3968 for some reason the current debugger (e.g. F<perl5db.pl> or a C<Devel::>
3969 module) didn't define a routine to be called at the beginning of each
3972 =item No dbm on this machine
3974 (P) This is counted as an internal error, because every machine should
3975 supply dbm nowadays, because Perl comes with SDBM. See L<SDBM_File>.
3977 =item No DB::sub routine defined
3979 (F) The currently executing code was compiled with the B<-d> switch, but
3980 for some reason the current debugger (e.g. F<perl5db.pl> or a C<Devel::>
3981 module) didn't define a C<DB::sub> routine to be called at the beginning
3982 of each ordinary subroutine call.
3984 =item No directory specified for -I
3986 (F) The B<-I> command-line switch requires a directory name as part of the
3987 I<same> argument. Use B<-Ilib>, for instance. B<-I lib> won't work.
3989 =item No error file after 2> or 2>> on command line
3991 (F) An error peculiar to VMS. Perl handles its own command line
3992 redirection, and found a '2>' or a '2>>' on the command line, but can't
3993 find the name of the file to which to write data destined for stderr.
3995 =item No group ending character '%c' found in template
3997 (F) A pack or unpack template has an opening '(' or '[' without its
3998 matching counterpart. See L<perlfunc/pack>.
4000 =item No input file after < on command line
4002 (F) An error peculiar to VMS. Perl handles its own command line
4003 redirection, and found a '<' on the command line, but can't find the
4004 name of the file from which to read data for stdin.
4006 =item No next::method '%s' found for %s
4008 (F) C<next::method> found no further instances of this method name
4009 in the remaining packages of the MRO of this class. If you don't want
4010 it throwing an exception, use C<maybe::next::method>
4011 or C<next::can>. See L<mro>.
4013 =item Non-finite repeat count does nothing
4015 (W numeric) You tried to execute the
4016 L<C<x>|perlop/Multiplicative Operators> repetition operator C<Inf> (or
4017 C<-Inf>) or C<NaN> times, which doesn't make sense.
4019 =item Non-hex character in regex; marked by S<<-- HERE> in m/%s/
4021 (F) In a regular expression, there was a non-hexadecimal character where
4022 a hex one was expected, like
4027 =item Non-octal character in regex; marked by S<<-- HERE> in m/%s/
4029 (F) In a regular expression, there was a non-octal character where
4030 an octal one was expected, like
4034 =item Non-octal character '%c'. Resolved as "%s"
4036 (W digit) In parsing an octal numeric constant, a character was
4037 unexpectedly encountered that isn't octal. The resulting value
4040 =item "no" not allowed in expression
4042 (F) The "no" keyword is recognized and executed at compile time, and
4043 returns no useful value. See L<perlmod>.
4045 =item Non-string passed as bitmask
4047 (W misc) A number has been passed as a bitmask argument to select().
4048 Use the vec() function to construct the file descriptor bitmasks for
4049 select. See L<perlfunc/select>.
4051 =item No output file after > on command line
4053 (F) An error peculiar to VMS. Perl handles its own command line
4054 redirection, and found a lone '>' at the end of the command line, so it
4055 doesn't know where you wanted to redirect stdout.
4057 =item No output file after > or >> on command line
4059 (F) An error peculiar to VMS. Perl handles its own command line
4060 redirection, and found a '>' or a '>>' on the command line, but can't
4061 find the name of the file to which to write data destined for stdout.
4063 =item No package name allowed for variable %s in "our"
4065 (F) Fully qualified variable names are not allowed in "our"
4066 declarations, because that doesn't make much sense under existing
4067 rules. Such syntax is reserved for future extensions.
4069 =item No Perl script found in input
4071 (F) You called C<perl -x>, but no line was found in the file beginning
4072 with #! and containing the word "perl".
4074 =item No setregid available
4076 (F) Configure didn't find anything resembling the setregid() call for
4079 =item No setreuid available
4081 (F) Configure didn't find anything resembling the setreuid() call for
4084 =item No such class %s
4086 (F) You provided a class qualifier in a "my", "our" or "state"
4087 declaration, but this class doesn't exist at this point in your program.
4089 =item No such class field "%s" in variable %s of type %s
4091 (F) You tried to access a key from a hash through the indicated typed
4092 variable but that key is not allowed by the package of the same type.
4093 The indicated package has restricted the set of allowed keys using the
4096 =item No such hook: %s
4098 (F) You specified a signal hook that was not recognized by Perl.
4099 Currently, Perl accepts C<__DIE__> and C<__WARN__> as valid signal hooks.
4101 =item No such pipe open
4103 (P) An error peculiar to VMS. The internal routine my_pclose() tried to
4104 close a pipe which hadn't been opened. This should have been caught
4105 earlier as an attempt to close an unopened filehandle.
4107 =item No such signal: SIG%s
4109 (W signal) You specified a signal name as a subscript to %SIG that was
4110 not recognized. Say C<kill -l> in your shell to see the valid signal
4111 names on your system.
4113 =item Not a CODE reference
4115 (F) Perl was trying to evaluate a reference to a code value (that is, a
4116 subroutine), but found a reference to something else instead. You can
4117 use the ref() function to find out what kind of ref it really was. See
4120 =item Not a GLOB reference
4122 (F) Perl was trying to evaluate a reference to a "typeglob" (that is, a
4123 symbol table entry that looks like C<*foo>), but found a reference to
4124 something else instead. You can use the ref() function to find out what
4125 kind of ref it really was. See L<perlref>.
4127 =item Not a HASH reference
4129 (F) Perl was trying to evaluate a reference to a hash value, but found a
4130 reference to something else instead. You can use the ref() function to
4131 find out what kind of ref it really was. See L<perlref>.
4133 =item '#' not allowed immediately following a sigil in a subroutine signature
4135 (F) In a subroutine signature definition, a comment following a sigil
4136 (C<$>, C<@> or C<%>), needs to be separated by whitespace or a commma etc., in
4137 particular to avoid confusion with the C<$#> variable. For example:
4140 sub f ($# ignore first arg
4143 sub f ($, # ignore first arg
4146 =item Not an ARRAY reference
4148 (F) Perl was trying to evaluate a reference to an array value, but found
4149 a reference to something else instead. You can use the ref() function
4150 to find out what kind of ref it really was. See L<perlref>.
4152 =item Not a SCALAR reference
4154 (F) Perl was trying to evaluate a reference to a scalar value, but found
4155 a reference to something else instead. You can use the ref() function
4156 to find out what kind of ref it really was. See L<perlref>.
4158 =item Not a subroutine reference
4160 (F) Perl was trying to evaluate a reference to a code value (that is, a
4161 subroutine), but found a reference to something else instead. You can
4162 use the ref() function to find out what kind of ref it really was. See
4165 =item Not a subroutine reference in overload table
4167 (F) An attempt was made to specify an entry in an overloading table that
4168 doesn't somehow point to a valid subroutine. See L<overload>.
4170 =item Not enough arguments for %s
4172 (F) The function requires more arguments than you specified.
4174 =item Not enough format arguments
4176 (W syntax) A format specified more picture fields than the next line
4177 supplied. See L<perlform>.
4181 (A) You've accidentally run your script through the Bourne shell instead
4182 of Perl. Check the #! line, or manually feed your script into Perl
4185 =item (?[...]) not valid in locale in regex; marked by S<<-- HERE> in m/%s/
4187 (F) C<(?[...])> cannot be used within the scope of a C<S<use locale>> or with
4188 an C</l> regular expression modifier, as that would require deferring
4189 to run-time the calculation of what it should evaluate to, and it is
4190 regex compile-time only.
4192 =item no UTC offset information; assuming local time is UTC
4194 (S) A warning peculiar to VMS. Perl was unable to find the local
4195 timezone offset, so it's assuming that local system time is equivalent
4196 to UTC. If it's not, define the logical name
4197 F<SYS$TIMEZONE_DIFFERENTIAL> to translate to the number of seconds which
4198 need to be added to UTC to get local time.
4200 =item NULL OP IN RUN
4202 (S debugging) Some internal routine called run() with a null opcode
4205 =item Null picture in formline
4207 (F) The first argument to formline must be a valid format picture
4208 specification. It was found to be empty, which probably means you
4209 supplied it an uninitialized value. See L<perlform>.
4213 (P) An attempt was made to realloc NULL.
4215 =item NULL regexp argument
4217 (P) The internal pattern matching routines blew it big time.
4219 =item NULL regexp parameter
4221 (P) The internal pattern matching routines are out of their gourd.
4223 =item Number too long
4225 (F) Perl limits the representation of decimal numbers in programs to
4226 about 250 characters. You've exceeded that length. Future
4227 versions of Perl are likely to eliminate this arbitrary limitation. In
4228 the meantime, try using scientific notation (e.g. "1e6" instead of
4231 =item Number with no digits
4233 (F) Perl was looking for a number but found nothing that looked like
4234 a number. This happens, for example with C<\o{}>, with no number between
4237 =item Octal number > 037777777777 non-portable
4239 (W portable) The octal number you specified is larger than 2**32-1
4240 (4294967295) and therefore non-portable between systems. See
4241 L<perlport> for more on portability concerns.
4243 =item Odd name/value argument for subroutine
4245 (F) A subroutine using a slurpy hash parameter in its signature
4246 received an odd number of arguments to populate the hash. It requires
4247 the arguments to be paired, with the same number of keys as values.
4248 The caller of the subroutine is presumably at fault.
4250 =item Odd number of arguments for overload::constant
4252 (W overload) The call to overload::constant contained an odd number of
4253 arguments. The arguments should come in pairs.
4255 =item Odd number of elements in anonymous hash
4257 (W misc) You specified an odd number of elements to initialize a hash,
4258 which is odd, because hashes come in key/value pairs.
4260 =item Odd number of elements in hash assignment
4262 (W misc) You specified an odd number of elements to initialize a hash,
4263 which is odd, because hashes come in key/value pairs.
4265 =item Offset outside string
4267 (F)(W layer) You tried to do a read/write/send/recv/seek operation
4268 with an offset pointing outside the buffer. This is difficult to
4269 imagine. The sole exceptions to this are that zero padding will
4270 take place when going past the end of the string when either
4271 C<sysread()>ing a file, or when seeking past the end of a scalar opened
4272 for I/O (in anticipation of future reads and to imitate the behavior
4275 =item %s() on unopened %s
4277 (W unopened) An I/O operation was attempted on a filehandle that was
4278 never initialized. You need to do an open(), a sysopen(), or a socket()
4279 call, or call a constructor from the FileHandle package.
4281 =item -%s on unopened filehandle %s
4283 (W unopened) You tried to invoke a file test operator on a filehandle
4284 that isn't open. Check your control flow. See also L<perlfunc/-X>.
4288 (S internal) An internal warning that the grammar is screwed up.
4292 (S internal) An internal warning that the grammar is screwed up.
4294 =item Opening dirhandle %s also as a file. This will be a fatal error in Perl 5.28
4296 (D io, deprecated) You used open() to associate a filehandle to
4297 a symbol (glob or scalar) that already holds a dirhandle.
4298 Although legal, this idiom might render your code confusing
4299 and this was deprecated in Perl 5.10. In Perl 5.28, this
4300 will be a fatal error.
4302 =item Opening filehandle %s also as a directory. This will be a fatal error in Perl 5.28
4304 (D io, deprecated) You used opendir() to associate a dirhandle to
4305 a symbol (glob or scalar) that already holds a filehandle.
4306 Although legal, this idiom might render your code confusing
4307 and this was deprecated in Perl 5.10. In Perl 5.28, this
4308 will be a fatal error.
4310 =item Operand with no preceding operator in regex; marked by S<<-- HERE> in
4313 (F) You wrote something like
4315 (?[ \p{Digit} \p{Thai} ])
4317 There are two operands, but no operator giving how you want to combine
4320 =item Operation "%s": no method found, %s
4322 (F) An attempt was made to perform an overloaded operation for which no
4323 handler was defined. While some handlers can be autogenerated in terms
4324 of other handlers, there is no default handler for any operation, unless
4325 the C<fallback> overloading key is specified to be true. See L<overload>.
4327 =item Operation "%s" returns its argument for non-Unicode code point 0x%X
4329 (S non_unicode) You performed an operation requiring Unicode rules
4330 on a code point that is not in Unicode, so what it should do is not
4331 defined. Perl has chosen to have it do nothing, and warn you.
4333 If the operation shown is "ToFold", it means that case-insensitive
4334 matching in a regular expression was done on the code point.
4336 If you know what you are doing you can turn off this warning by
4337 C<no warnings 'non_unicode';>.
4339 =item Operation "%s" returns its argument for UTF-16 surrogate U+%X
4341 (S surrogate) You performed an operation requiring Unicode
4342 rules on a Unicode surrogate. Unicode frowns upon the use
4343 of surrogates for anything but storing strings in UTF-16, but
4344 rules are (reluctantly) defined for the surrogates, and
4345 they are to do nothing for this operation. Because the use of
4346 surrogates can be dangerous, Perl warns.
4348 If the operation shown is "ToFold", it means that case-insensitive
4349 matching in a regular expression was done on the code point.
4351 If you know what you are doing you can turn off this warning by
4352 C<no warnings 'surrogate';>.
4354 =item Operator or semicolon missing before %s
4356 (S ambiguous) You used a variable or subroutine call where the parser
4357 was expecting an operator. The parser has assumed you really meant to
4358 use an operator, but this is highly likely to be incorrect. For
4359 example, if you say "*foo *foo" it will be interpreted as if you said
4362 =item Optional parameter lacks default expression
4364 (F) In a subroutine signature, you wrote something like "$a =", making a
4365 named optional parameter without a default value. A nameless optional
4366 parameter is permitted to have no default value, but a named one must
4367 have a specific default. You probably want "$a = undef".
4369 =item "our" variable %s redeclared
4371 (W misc) You seem to have already declared the same global once before
4372 in the current lexical scope.
4374 =item Out of memory!
4376 (X) The malloc() function returned 0, indicating there was insufficient
4377 remaining memory (or virtual memory) to satisfy the request. Perl has
4378 no option but to exit immediately.
4380 At least in Unix you may be able to get past this by increasing your
4381 process datasize limits: in csh/tcsh use C<limit> and
4382 C<limit datasize n> (where C<n> is the number of kilobytes) to check
4383 the current limits and change them, and in ksh/bash/zsh use C<ulimit -a>
4384 and C<ulimit -d n>, respectively.
4386 =item Out of memory during %s extend
4388 (X) An attempt was made to extend an array, a list, or a string beyond
4389 the largest possible memory allocation.
4391 =item Out of memory during "large" request for %s
4393 (F) The malloc() function returned 0, indicating there was insufficient
4394 remaining memory (or virtual memory) to satisfy the request. However,
4395 the request was judged large enough (compile-time default is 64K), so a
4396 possibility to shut down by trapping this error is granted.
4398 =item Out of memory during request for %s
4400 (X)(F) The malloc() function returned 0, indicating there was
4401 insufficient remaining memory (or virtual memory) to satisfy the
4404 The request was judged to be small, so the possibility to trap it
4405 depends on the way perl was compiled. By default it is not trappable.
4406 However, if compiled for this, Perl may use the contents of C<$^M> as an
4407 emergency pool after die()ing with this message. In this case the error
4408 is trappable I<once>, and the error message will include the line and file
4409 where the failed request happened.
4411 =item Out of memory during ridiculously large request
4413 (F) You can't allocate more than 2^31+"small amount" bytes. This error
4414 is most likely to be caused by a typo in the Perl program. e.g.,
4415 C<$arr[time]> instead of C<$arr[$time]>.
4417 =item Out of memory for yacc stack
4419 (F) The yacc parser wanted to grow its stack so it could continue
4420 parsing, but realloc() wouldn't give it more memory, virtual or
4423 =item '.' outside of string in pack
4425 (F) The argument to a '.' in your template tried to move the working
4426 position to before the start of the packed string being built.
4428 =item '@' outside of string in unpack
4430 (F) You had a template that specified an absolute position outside
4431 the string being unpacked. See L<perlfunc/pack>.
4433 =item '@' outside of string with malformed UTF-8 in unpack
4435 (F) You had a template that specified an absolute position outside
4436 the string being unpacked. The string being unpacked was also invalid
4437 UTF-8. See L<perlfunc/pack>.
4439 =item overload arg '%s' is invalid
4441 (W overload) The L<overload> pragma was passed an argument it did not
4442 recognize. Did you mistype an operator?
4444 =item Overloaded dereference did not return a reference
4446 (F) An object with an overloaded dereference operator was dereferenced,
4447 but the overloaded operation did not return a reference. See
4450 =item Overloaded qr did not return a REGEXP
4452 (F) An object with a C<qr> overload was used as part of a match, but the
4453 overloaded operation didn't return a compiled regexp. See L<overload>.
4455 =item %s package attribute may clash with future reserved word: %s
4457 (W reserved) A lowercase attribute name was used that had a
4458 package-specific handler. That name might have a meaning to Perl itself
4459 some day, even though it doesn't yet. Perhaps you should use a
4460 mixed-case attribute name, instead. See L<attributes>.
4462 =item pack/unpack repeat count overflow
4464 (F) You can't specify a repeat count so large that it overflows your
4465 signed integers. See L<perlfunc/pack>.
4469 (W io) A single call to write() produced more lines than can fit on a
4470 page. See L<perlform>.
4474 (P) An internal error.
4476 =item panic: attempt to call %s in %s
4478 (P) One of the file test operators entered a code branch that calls
4479 an ACL related-function, but that function is not available on this
4480 platform. Earlier checks mean that it should not be possible to
4481 enter this branch on this platform.
4483 =item panic: child pseudo-process was never scheduled
4485 (P) A child pseudo-process in the ithreads implementation on Windows
4486 was not scheduled within the time period allowed and therefore was not
4487 able to initialize properly.
4489 =item panic: ck_grep, type=%u
4491 (P) Failed an internal consistency check trying to compile a grep.
4493 =item panic: corrupt saved stack index %ld
4495 (P) The savestack was requested to restore more localized values than
4496 there are in the savestack.
4498 =item panic: del_backref
4500 (P) Failed an internal consistency check while trying to reset a weak
4503 =item panic: do_subst
4505 (P) The internal pp_subst() routine was called with invalid operational
4508 =item panic: do_trans_%s
4510 (P) The internal do_trans routines were called with invalid operational
4513 =item panic: fold_constants JMPENV_PUSH returned %d
4515 (P) While attempting folding constants an exception other than an C<eval>
4518 =item panic: frexp: %f
4520 (P) The library function frexp() failed, making printf("%f") impossible.
4522 =item panic: goto, type=%u, ix=%ld
4524 (P) We popped the context stack to a context with the specified label,
4525 and then discovered it wasn't a context we know how to do a goto in.
4527 =item panic: gp_free failed to free glob pointer
4529 (P) The internal routine used to clear a typeglob's entries tried
4530 repeatedly, but each time something re-created entries in the glob.
4531 Most likely the glob contains an object with a reference back to
4532 the glob and a destructor that adds a new object to the glob.
4534 =item panic: INTERPCASEMOD, %s
4536 (P) The lexer got into a bad state at a case modifier.
4538 =item panic: INTERPCONCAT, %s
4540 (P) The lexer got into a bad state parsing a string with brackets.
4542 =item panic: kid popen errno read
4544 (F) A forked child returned an incomprehensible message about its errno.
4546 =item panic: last, type=%u
4548 (P) We popped the context stack to a block context, and then discovered
4549 it wasn't a block context.
4551 =item panic: leave_scope clearsv
4553 (P) A writable lexical variable became read-only somehow within the
4556 =item panic: leave_scope inconsistency %u
4558 (P) The savestack probably got out of sync. At least, there was an
4559 invalid enum on the top of it.
4561 =item panic: magic_killbackrefs
4563 (P) Failed an internal consistency check while trying to reset all weak
4564 references to an object.
4566 =item panic: malloc, %s
4568 (P) Something requested a negative number of bytes of malloc.
4570 =item panic: memory wrap
4572 (P) Something tried to allocate either more memory than possible or a
4575 =item panic: pad_alloc, %p!=%p
4577 (P) The compiler got confused about which scratch pad it was allocating
4578 and freeing temporaries and lexicals from.
4580 =item panic: pad_free curpad, %p!=%p
4582 (P) The compiler got confused about which scratch pad it was allocating
4583 and freeing temporaries and lexicals from.
4585 =item panic: pad_free po
4587 (P) A zero scratch pad offset was detected internally. An attempt was
4588 made to free a target that had not been allocated to begin with.
4590 =item panic: pad_reset curpad, %p!=%p
4592 (P) The compiler got confused about which scratch pad it was allocating
4593 and freeing temporaries and lexicals from.
4595 =item panic: pad_sv po
4597 (P) A zero scratch pad offset was detected internally. Most likely
4598 an operator needed a target but that target had not been allocated
4599 for whatever reason.
4601 =item panic: pad_swipe curpad, %p!=%p
4603 (P) The compiler got confused about which scratch pad it was allocating
4604 and freeing temporaries and lexicals from.
4606 =item panic: pad_swipe po
4608 (P) An invalid scratch pad offset was detected internally.
4610 =item panic: pp_iter, type=%u
4612 (P) The foreach iterator got called in a non-loop context frame.
4614 =item panic: pp_match%s
4616 (P) The internal pp_match() routine was called with invalid operational
4619 =item panic: realloc, %s
4621 (P) Something requested a negative number of bytes of realloc.
4623 =item panic: reference miscount on nsv in sv_replace() (%d != 1)
4625 (P) The internal sv_replace() function was handed a new SV with a
4626 reference count other than 1.
4628 =item panic: restartop in %s
4630 (P) Some internal routine requested a goto (or something like it), and
4631 didn't supply the destination.
4633 =item panic: return, type=%u
4635 (P) We popped the context stack to a subroutine or eval context, and
4636 then discovered it wasn't a subroutine or eval context.
4638 =item panic: scan_num, %s
4640 (P) scan_num() got called on something that wasn't a number.
4642 =item panic: Sequence (?{...}): no code block found in regex m/%s/
4644 (P) While compiling a pattern that has embedded (?{}) or (??{}) code
4645 blocks, perl couldn't locate the code block that should have already been
4646 seen and compiled by perl before control passed to the regex compiler.
4648 =item panic: strxfrm() gets absurd - a => %u, ab => %u
4650 (P) The interpreter's sanity check of the C function strxfrm() failed.
4651 In your current locale the returned transformation of the string "ab"
4652 is shorter than that of the string "a", which makes no sense.
4654 =item panic: sv_chop %s
4656 (P) The sv_chop() routine was passed a position that is not within the
4657 scalar's string buffer.
4659 =item panic: sv_insert, midend=%p, bigend=%p
4661 (P) The sv_insert() routine was told to remove more string than there
4664 =item panic: top_env
4666 (P) The compiler attempted to do a goto, or something weird like that.
4668 =item panic: unimplemented op %s (#%d) called
4670 (P) The compiler is screwed up and attempted to use an op that isn't
4671 permitted at run time.
4673 =item panic: unknown OA_*: %x
4675 (P) The internal routine that handles arguments to C<&CORE::foo()>
4676 subroutine calls was unable to determine what type of arguments
4679 =item panic: utf16_to_utf8: odd bytelen
4681 (P) Something tried to call utf16_to_utf8 with an odd (as opposed
4682 to even) byte length.
4684 =item panic: utf16_to_utf8_reversed: odd bytelen
4686 (P) Something tried to call utf16_to_utf8_reversed with an odd (as opposed
4687 to even) byte length.
4689 =item panic: yylex, %s
4691 (P) The lexer got into a bad state while processing a case modifier.
4693 =item Parentheses missing around "%s" list
4695 (W parenthesis) You said something like
4701 my ($foo, $bar) = @_;
4703 Remember that "my", "our", "local" and "state" bind tighter than comma.
4705 =item Parsing code internal error (%s)
4707 (F) Parsing code supplied by an extension violated the parser's API in
4710 =item Pattern subroutine nesting without pos change exceeded limit in regex
4712 (F) You used a pattern that uses too many nested subpattern calls without
4713 consuming any text. Restructure the pattern so text is consumed before
4714 the nesting limit is exceeded.
4716 =item C<-p> destination: %s
4718 (F) An error occurred during the implicit output invoked by the C<-p>
4719 command-line switch. (This output goes to STDOUT unless you've
4720 redirected it with select().)
4722 =item Perl API version %s of %s does not match %s
4724 (F) The XS module in question was compiled against a different incompatible
4725 version of Perl than the one that has loaded the XS module.
4727 =item Perl folding rules are not up-to-date for 0x%X; please use the perlbug
4728 utility to report; in regex; marked by S<<-- HERE> in m/%s/
4730 (S regexp) You used a regular expression with case-insensitive matching,
4731 and there is a bug in Perl in which the built-in regular expression
4732 folding rules are not accurate. This may lead to incorrect results.
4733 Please report this as a bug using the L<perlbug> utility.
4735 =item PerlIO layer ':win32' is experimental
4737 (S experimental::win32_perlio) The C<:win32> PerlIO layer is
4738 experimental. If you want to take the risk of using this layer,
4739 simply disable this warning:
4741 no warnings "experimental::win32_perlio";
4743 =item Perl_my_%s() not available
4745 (F) Your platform has very uncommon byte-order and integer size,
4746 so it was not possible to set up some or all fixed-width byte-order
4747 conversion functions. This is only a problem when you're using the
4748 '<' or '>' modifiers in (un)pack templates. See L<perlfunc/pack>.
4750 =item Perl %s required (did you mean %s?)--this is only %s, stopped
4752 (F) The code you are trying to run has asked for a newer version of
4753 Perl than you are running. Perhaps C<use 5.10> was written instead
4754 of C<use 5.010> or C<use v5.10>. Without the leading C<v>, the number is
4755 interpreted as a decimal, with every three digits after the
4756 decimal point representing a part of the version number. So 5.10
4757 is equivalent to v5.100.
4759 =item Perl %s required--this is only %s, stopped
4761 (F) The module in question uses features of a version of Perl more
4762 recent than the currently running version. How long has it been since
4763 you upgraded, anyway? See L<perlfunc/require>.
4765 =item PERL_SH_DIR too long
4767 (F) An error peculiar to OS/2. PERL_SH_DIR is the directory to find the
4768 C<sh>-shell in. See "PERL_SH_DIR" in L<perlos2>.
4770 =item PERL_SIGNALS illegal: "%s"
4772 (X) See L<perlrun/PERL_SIGNALS> for legal values.
4774 =item Perls since %s too modern--this is %s, stopped
4776 (F) The code you are trying to run claims it will not run
4777 on the version of Perl you are using because it is too new.
4778 Maybe the code needs to be updated, or maybe it is simply
4779 wrong and the version check should just be removed.
4781 =item perl: warning: Non hex character in '$ENV{PERL_HASH_SEED}', seed only partially set
4783 (S) PERL_HASH_SEED should match /^\s*(?:0x)?[0-9a-fA-F]+\s*\z/ but it
4784 contained a non hex character. This could mean you are not using the
4785 hash seed you think you are.
4787 =item perl: warning: Setting locale failed.
4789 (S) The whole warning message will look something like:
4791 perl: warning: Setting locale failed.
4792 perl: warning: Please check that your locale settings:
4795 are supported and installed on your system.
4796 perl: warning: Falling back to the standard locale ("C").
4798 Exactly what were the failed locale settings varies. In the above the
4799 settings were that the LC_ALL was "En_US" and the LANG had no value.
4800 This error means that Perl detected that you and/or your operating
4801 system supplier and/or system administrator have set up the so-called
4802 locale system but Perl could not use those settings. This was not
4803 dead serious, fortunately: there is a "default locale" called "C" that
4804 Perl can and will use, and the script will be run. Before you really
4805 fix the problem, however, you will get the same error message each
4806 time you run Perl. How to really fix the problem can be found in
4807 L<perllocale> section B<LOCALE PROBLEMS>.
4809 =item perl: warning: strange setting in '$ENV{PERL_PERTURB_KEYS}': '%s'
4811 (S) Perl was run with the environment variable PERL_PERTURB_KEYS defined
4812 but containing an unexpected value. The legal values of this setting
4815 Numeric | String | Result
4816 --------+---------------+-----------------------------------------
4817 0 | NO | Disables key traversal randomization
4818 1 | RANDOM | Enables full key traversal randomization
4819 2 | DETERMINISTIC | Enables repeatable key traversal
4822 Both numeric and string values are accepted, but note that string values are
4823 case sensitive. The default for this setting is "RANDOM" or 1.
4825 =item pid %x not a child
4827 (W exec) A warning peculiar to VMS. Waitpid() was asked to wait for a
4828 process which isn't a subprocess of the current process. While this is
4829 fine from VMS' perspective, it's probably not what you intended.
4831 =item 'P' must have an explicit size in unpack
4833 (F) The unpack format P must have an explicit size, not "*".
4835 =item POSIX class [:%s:] unknown in regex; marked by S<<-- HERE> in m/%s/
4837 (F) The class in the character class [: :] syntax is unknown. The S<<-- HERE>
4838 shows whereabouts in the regular expression the problem was discovered.
4839 Note that the POSIX character classes do B<not> have the C<is> prefix
4840 the corresponding C interfaces have: in other words, it's C<[[:print:]]>,
4841 not C<isprint>. See L<perlre>.
4843 =item POSIX getpgrp can't take an argument
4845 (F) Your system has POSIX getpgrp(), which takes no argument, unlike
4846 the BSD version, which takes a pid.
4848 =item POSIX syntax [%c %c] belongs inside character classes%s in regex; marked by
4849 S<<-- HERE> in m/%s/
4851 (W regexp) Perl thinks that you intended to write a POSIX character
4852 class, but didn't use enough brackets. These POSIX class constructs [:
4853 :], [= =], and [. .] go I<inside> character classes, the [] are part of
4854 the construct, for example: C<qr/[012[:alpha:]345]/>. What the regular
4855 expression pattern compiled to is probably not what you were intending.
4856 For example, C<qr/[:alpha:]/> compiles to a regular bracketed character
4857 class consisting of the four characters C<":">, C<"a">, C<"l">,
4858 C<"h">, and C<"p">. To specify the POSIX class, it should have been
4859 written C<qr/[[:alpha:]]/>.
4861 Note that [= =] and [. .] are not currently
4862 implemented; they are simply placeholders for future extensions and
4863 will cause fatal errors. The S<<-- HERE> shows whereabouts in the regular
4864 expression the problem was discovered. See L<perlre>.
4866 If the specification of the class was not completely valid, the message
4869 =item POSIX syntax [. .] is reserved for future extensions in regex; marked by
4870 S<<-- HERE> in m/%s/
4872 (F) Within regular expression character classes ([]) the syntax beginning
4873 with "[." and ending with ".]" is reserved for future extensions. If you
4874 need to represent those character sequences inside a regular expression
4875 character class, just quote the square brackets with the backslash: "\[."
4876 and ".\]". The S<<-- HERE> shows whereabouts in the regular expression the
4877 problem was discovered. See L<perlre>.
4879 =item POSIX syntax [= =] is reserved for future extensions in regex; marked by
4880 S<<-- HERE> in m/%s/
4882 (F) Within regular expression character classes ([]) the syntax beginning
4883 with "[=" and ending with "=]" is reserved for future extensions. If you
4884 need to represent those character sequences inside a regular expression
4885 character class, just quote the square brackets with the backslash: "\[="
4886 and "=\]". The S<<-- HERE> shows whereabouts in the regular expression the
4887 problem was discovered. See L<perlre>.
4889 =item Possible attempt to put comments in qw() list
4891 (W qw) qw() lists contain items separated by whitespace; as with literal
4892 strings, comment characters are not ignored, but are instead treated as
4893 literal data. (You may have used different delimiters than the
4894 parentheses shown here; braces are also frequently used.)
4896 You probably wrote something like this:
4903 when you should have written this:
4910 If you really want comments, build your list the
4911 old-fashioned way, with quotes and commas:
4915 'b', # another comment
4918 =item Possible attempt to separate words with commas
4920 (W qw) qw() lists contain items separated by whitespace; therefore
4921 commas aren't needed to separate the items. (You may have used
4922 different delimiters than the parentheses shown here; braces are also
4925 You probably wrote something like this:
4929 which puts literal commas into some of the list items. Write it without
4930 commas if you don't want them to appear in your data:
4934 =item Possible memory corruption: %s overflowed 3rd argument
4936 (F) An ioctl() or fcntl() returned more than Perl was bargaining for.
4937 Perl guesses a reasonable buffer size, but puts a sentinel byte at the
4938 end of the buffer just in case. This sentinel byte got clobbered, and
4939 Perl assumes that memory is now corrupted. See L<perlfunc/ioctl>.
4941 =item Possible precedence issue with control flow operator
4943 (W syntax) There is a possible problem with the mixing of a control
4944 flow operator (e.g. C<return>) and a low-precedence operator like
4947 sub { return $a or $b; }
4951 sub { (return $a) or $b; }
4953 Which is effectively just:
4957 Either use parentheses or the high-precedence variant of the operator.
4959 Note this may be also triggered for constructs like:
4963 =item Possible precedence problem on bitwise %s operator
4965 (W precedence) Your program uses a bitwise logical operator in conjunction
4966 with a numeric comparison operator, like this :
4968 if ($x & $y == 0) { ... }
4970 This expression is actually equivalent to C<$x & ($y == 0)>, due to the
4971 higher precedence of C<==>. This is probably not what you want. (If you
4972 really meant to write this, disable the warning, or, better, put the
4973 parentheses explicitly and write C<$x & ($y == 0)>).
4975 =item Possible unintended interpolation of $\ in regex
4977 (W ambiguous) You said something like C<m/$\/> in a regex.
4978 The regex C<m/foo$\s+bar/m> translates to: match the word 'foo', the output
4979 record separator (see L<perlvar/$\>) and the letter 's' (one time or more)
4980 followed by the word 'bar'.
4982 If this is what you intended then you can silence the warning by using
4983 C<m/${\}/> (for example: C<m/foo${\}s+bar/>).
4985 If instead you intended to match the word 'foo' at the end of the line
4986 followed by whitespace and the word 'bar' on the next line then you can use
4987 C<m/$(?)\/> (for example: C<m/foo$(?)\s+bar/>).
4989 =item Possible unintended interpolation of %s in string
4991 (W ambiguous) You said something like '@foo' in a double-quoted string
4992 but there was no array C<@foo> in scope at the time. If you wanted a
4993 literal @foo, then write it as \@foo; otherwise find out what happened
4994 to the array you apparently lost track of.
4996 =item Precedence problem: open %s should be open(%s)
4998 (S precedence) The old irregular construct
5002 is now misinterpreted as
5006 because of the strict regularization of Perl 5's grammar into unary and
5007 list operators. (The old open was a little of both.) You must put
5008 parentheses around the filehandle, or use the new "or" operator instead
5011 =item Premature end of script headers
5013 See L</500 Server error>.
5015 =item printf() on closed filehandle %s
5017 (W closed) The filehandle you're writing to got itself closed sometime
5018 before now. Check your control flow.
5020 =item print() on closed filehandle %s
5022 (W closed) The filehandle you're printing on got itself closed sometime
5023 before now. Check your control flow.
5025 =item Process terminated by SIG%s
5027 (W) This is a standard message issued by OS/2 applications, while *nix
5028 applications die in silence. It is considered a feature of the OS/2
5029 port. One can easily disable this by appropriate sighandlers, see
5030 L<perlipc/"Signals">. See also "Process terminated by SIGTERM/SIGINT"
5033 =item Prototype after '%c' for %s : %s
5035 (W illegalproto) A character follows % or @ in a prototype. This is
5036 useless, since % and @ gobble the rest of the subroutine arguments.
5038 =item Prototype mismatch: %s vs %s
5040 (S prototype) The subroutine being declared or defined had previously been
5041 declared or defined with a different function prototype.
5043 =item Prototype not terminated
5045 (F) You've omitted the closing parenthesis in a function prototype
5048 =item Prototype '%s' overridden by attribute 'prototype(%s)' in %s
5050 (W prototype) A prototype was declared in both the parentheses after
5051 the sub name and via the prototype attribute. The prototype in
5052 parentheses is useless, since it will be replaced by the prototype
5053 from the attribute before it's ever used.
5055 =item Quantifier follows nothing in regex; marked by S<<-- HERE> in m/%s/
5057 (F) You started a regular expression with a quantifier. Backslash it if
5058 you meant it literally. The S<<-- HERE> shows whereabouts in the regular
5059 expression the problem was discovered. See L<perlre>.
5061 =item Quantifier in {,} bigger than %d in regex; marked by S<<-- HERE> in m/%s/
5063 (F) There is currently a limit to the size of the min and max values of
5064 the {min,max} construct. The S<<-- HERE> shows whereabouts in the regular
5065 expression the problem was discovered. See L<perlre>.
5067 =item Quantifier {n,m} with n > m can't match in regex
5069 =item Quantifier {n,m} with n > m can't match in regex; marked by
5070 S<<-- HERE> in m/%s/
5072 (W regexp) Minima should be less than or equal to maxima. If you really
5073 want your regexp to match something 0 times, just put {0}.
5075 =item Quantifier unexpected on zero-length expression in regex m/%s/
5077 (W regexp) You applied a regular expression quantifier in a place where
5078 it makes no sense, such as on a zero-width assertion. Try putting the
5079 quantifier inside the assertion instead. For example, the way to match
5080 "abc" provided that it is followed by three repetitions of "xyz" is
5081 C</abc(?=(?:xyz){3})/>, not C</abc(?=xyz){3}/>.
5083 =item Range iterator outside integer range
5085 (F) One (or both) of the numeric arguments to the range operator ".."
5086 are outside the range which can be represented by integers internally.
5087 One possible workaround is to force Perl to use magical string increment
5088 by prepending "0" to your numbers.
5090 =item Ranges of ASCII printables should be some subset of "0-9", "A-Z", or
5091 "a-z" in regex; marked by S<<-- HERE> in m/%s/
5093 (W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
5095 Stricter rules help to find typos and other errors. Perhaps you didn't
5096 even intend a range here, if the C<"-"> was meant to be some other
5097 character, or should have been escaped (like C<"\-">). If you did
5098 intend a range, the one that was used is not portable between ASCII and
5099 EBCDIC platforms, and doesn't have an obvious meaning to a casual
5102 [3-7] # OK; Obvious and portable
5103 [d-g] # OK; Obvious and portable
5104 [A-Y] # OK; Obvious and portable
5105 [A-z] # WRONG; Not portable; not clear what is meant
5106 [a-Z] # WRONG; Not portable; not clear what is meant
5107 [%-.] # WRONG; Not portable; not clear what is meant
5108 [\x41-Z] # WRONG; Not portable; not obvious to non-geek
5110 (You can force portability by specifying a Unicode range, which means that
5111 the endpoints are specified by
5112 L<C<\N{...}>|perlrecharclass/Character Ranges>, but the meaning may
5113 still not be obvious.)
5114 The stricter rules require that ranges that start or stop with an ASCII
5115 character that is not a control have all their endpoints be the literal
5116 character, and not some escape sequence (like C<"\x41">), and the ranges
5117 must be all digits, or all uppercase letters, or all lowercase letters.
5119 =item Ranges of digits should be from the same group in regex; marked by
5120 S<<-- HERE> in m/%s/
5122 (W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
5124 Stricter rules help to find typos and other errors. You included a
5125 range, and at least one of the end points is a decimal digit. Under the
5126 stricter rules, when this happens, both end points should be digits in
5127 the same group of 10 consecutive digits.
5129 =item readdir() attempted on invalid dirhandle %s
5131 (W io) The dirhandle you're reading from is either closed or not really
5132 a dirhandle. Check your control flow.
5134 =item readline() on closed filehandle %s
5136 (W closed) The filehandle you're reading from got itself closed sometime
5137 before now. Check your control flow.
5139 =item read() on closed filehandle %s
5141 (W closed) You tried to read from a closed filehandle.
5143 =item read() on unopened filehandle %s
5145 (W unopened) You tried to read from a filehandle that was never opened.
5147 =item Reallocation too large: %x
5149 (F) You can't allocate more than 64K on an MS-DOS machine.
5151 =item realloc() of freed memory ignored
5153 (S malloc) An internal routine called realloc() on something that had
5156 =item Recompile perl with B<-D>DEBUGGING to use B<-D> switch
5158 (S debugging) You can't use the B<-D> option unless the code to produce
5159 the desired output is compiled into Perl, which entails some overhead,
5160 which is why it's currently left out of your copy.
5162 =item Recursive call to Perl_load_module in PerlIO_find_layer
5164 (P) It is currently not permitted to load modules when creating
5165 a filehandle inside an %INC hook. This can happen with C<open my
5166 $fh, '<', \$scalar>, which implicitly loads PerlIO::scalar. Try
5167 loading PerlIO::scalar explicitly first.
5169 =item Recursive inheritance detected in package '%s'
5171 (F) While calculating the method resolution order (MRO) of a package, Perl
5172 believes it found an infinite loop in the C<@ISA> hierarchy. This is a
5173 crude check that bails out after 100 levels of C<@ISA> depth.
5175 =item Redundant argument in %s
5177 (W redundant) You called a function with more arguments than other
5178 arguments you supplied indicated would be needed. Currently only
5179 emitted when a printf-type format required fewer arguments than were
5180 supplied, but might be used in the future for e.g. L<perlfunc/pack>.
5182 =item refcnt_dec: fd %d%s
5184 =item refcnt: fd %d%s
5186 =item refcnt_inc: fd %d%s
5188 (P) Perl's I/O implementation failed an internal consistency check. If
5189 you see this message, something is very wrong.
5191 =item Reference found where even-sized list expected
5193 (W misc) You gave a single reference where Perl was expecting a list
5194 with an even number of elements (for assignment to a hash). This
5195 usually means that you used the anon hash constructor when you meant
5196 to use parens. In any case, a hash requires key/value B<pairs>.
5198 %hash = { one => 1, two => 2, }; # WRONG
5199 %hash = [ qw/ an anon array / ]; # WRONG
5200 %hash = ( one => 1, two => 2, ); # right
5201 %hash = qw( one 1 two 2 ); # also fine
5203 =item Reference is already weak
5205 (W misc) You have attempted to weaken a reference that is already weak.
5206 Doing so has no effect.
5208 =item Reference to invalid group 0 in regex; marked by S<<-- HERE> in m/%s/
5210 (F) You used C<\g0> or similar in a regular expression. You may refer
5211 to capturing parentheses only with strictly positive integers
5212 (normal backreferences) or with strictly negative integers (relative
5213 backreferences). Using 0 does not make sense.
5215 =item Reference to nonexistent group in regex; marked by S<<-- HERE> in
5218 (F) You used something like C<\7> in your regular expression, but there are
5219 not at least seven sets of capturing parentheses in the expression. If
5220 you wanted to have the character with ordinal 7 inserted into the regular
5221 expression, prepend zeroes to make it three digits long: C<\007>
5223 The S<<-- HERE> shows whereabouts in the regular expression the problem was
5226 =item Reference to nonexistent named group in regex; marked by S<<-- HERE>
5229 (F) You used something like C<\k'NAME'> or C<< \k<NAME> >> in your regular
5230 expression, but there is no corresponding named capturing parentheses
5231 such as C<(?'NAME'...)> or C<< (?<NAME>...) >>. Check if the name has been
5232 spelled correctly both in the backreference and the declaration.
5234 The S<<-- HERE> shows whereabouts in the regular expression the problem was
5237 =item Reference to nonexistent or unclosed group in regex; marked by
5238 S<<-- HERE> in m/%s/
5240 (F) You used something like C<\g{-7}> in your regular expression, but there
5241 are not at least seven sets of closed capturing parentheses in the
5242 expression before where the C<\g{-7}> was located.
5244 The S<<-- HERE> shows whereabouts in the regular expression the problem was
5247 =item regexp memory corruption
5249 (P) The regular expression engine got confused by what the regular
5250 expression compiler gave it.
5252 =item Regexp modifier "/%c" may appear a maximum of twice
5254 =item Regexp modifier "%c" may appear a maximum of twice in regex; marked
5255 by S<<-- HERE> in m/%s/
5257 (F) The regular expression pattern had too many occurrences
5258 of the specified modifier. Remove the extraneous ones.
5260 =item Regexp modifier "%c" may not appear after the "-" in regex; marked by <--
5263 (F) Turning off the given modifier has the side effect of turning on
5264 another one. Perl currently doesn't allow this. Reword the regular
5265 expression to use the modifier you want to turn on (and place it before
5266 the minus), instead of the one you want to turn off.
5268 =item Regexp modifier "/%c" may not appear twice
5270 =item Regexp modifier "%c" may not appear twice in regex; marked by <--
5273 (F) The regular expression pattern had too many occurrences
5274 of the specified modifier. Remove the extraneous ones.
5276 =item Regexp modifiers "/%c" and "/%c" are mutually exclusive
5278 =item Regexp modifiers "%c" and "%c" are mutually exclusive in regex;
5279 marked by S<<-- HERE> in m/%s/
5281 (F) The regular expression pattern had more than one of these
5282 mutually exclusive modifiers. Retain only the modifier that is
5283 supposed to be there.
5285 =item Regexp out of space in regex m/%s/
5287 (P) A "can't happen" error, because safemalloc() should have caught it
5290 =item Repeated format line will never terminate (~~ and @#)
5292 (F) Your format contains the ~~ repeat-until-blank sequence and a
5293 numeric field that will never go blank so that the repetition never
5294 terminates. You might use ^# instead. See L<perlform>.
5296 =item Replacement list is longer than search list
5298 (W misc) You have used a replacement list that is longer than the
5299 search list. So the additional elements in the replacement list
5302 =item '%s' resolved to '\o{%s}%d'
5304 (W misc, regexp) You wrote something like C<\08>, or C<\179> in a
5305 double-quotish string. All but the last digit is treated as a single
5306 character, specified in octal. The last digit is the next character in
5307 the string. To tell Perl that this is indeed what you want, you can use
5308 the C<\o{ }> syntax, or use exactly three digits to specify the octal
5311 =item Reversed %s= operator
5313 (W syntax) You wrote your assignment operator backwards. The = must
5314 always come last, to avoid ambiguity with subsequent unary operators.
5316 =item rewinddir() attempted on invalid dirhandle %s
5318 (W io) The dirhandle you tried to do a rewinddir() on is either closed
5319 or not really a dirhandle. Check your control flow.
5321 =item Scalars leaked: %d
5323 (S internal) Something went wrong in Perl's internal bookkeeping
5324 of scalars: not all scalar variables were deallocated by the time
5325 Perl exited. What this usually indicates is a memory leak, which
5326 is of course bad, especially if the Perl program is intended to be
5329 =item Scalar value @%s[%s] better written as $%s[%s]
5331 (W syntax) You've used an array slice (indicated by @) to select a
5332 single element of an array. Generally it's better to ask for a scalar
5333 value (indicated by $). The difference is that C<$foo[&bar]> always
5334 behaves like a scalar, both when assigning to it and when evaluating its
5335 argument, while C<@foo[&bar]> behaves like a list when you assign to it,
5336 and provides a list context to its subscript, which can do weird things
5337 if you're expecting only one subscript.
5339 On the other hand, if you were actually hoping to treat the array
5340 element as a list, you need to look into how references work, because
5341 Perl will not magically convert between scalars and lists for you. See
5344 =item Scalar value @%s{%s} better written as $%s{%s}
5346 (W syntax) You've used a hash slice (indicated by @) to select a single
5347 element of a hash. Generally it's better to ask for a scalar value
5348 (indicated by $). The difference is that C<$foo{&bar}> always behaves
5349 like a scalar, both when assigning to it and when evaluating its
5350 argument, while C<@foo{&bar}> behaves like a list when you assign to it,
5351 and provides a list context to its subscript, which can do weird things
5352 if you're expecting only one subscript.
5354 On the other hand, if you were actually hoping to treat the hash element
5355 as a list, you need to look into how references work, because Perl will
5356 not magically convert between scalars and lists for you. See
5359 =item Search pattern not terminated
5361 (F) The lexer couldn't find the final delimiter of a // or m{}
5362 construct. Remember that bracketing delimiters count nesting level.
5363 Missing the leading C<$> from a variable C<$m> may cause this error.
5365 Note that since Perl 5.10.0 a // can also be the I<defined-or>
5366 construct, not just the empty search pattern. Therefore code written
5367 in Perl 5.10.0 or later that uses the // as the I<defined-or> can be
5368 misparsed by pre-5.10.0 Perls as a non-terminated search pattern.
5370 =item seekdir() attempted on invalid dirhandle %s
5372 (W io) The dirhandle you are doing a seekdir() on is either closed or not
5373 really a dirhandle. Check your control flow.
5375 =item %sseek() on unopened filehandle
5377 (W unopened) You tried to use the seek() or sysseek() function on a
5378 filehandle that was either never opened or has since been closed.
5380 =item select not implemented
5382 (F) This machine doesn't implement the select() system call.
5384 =item Self-ties of arrays and hashes are not supported
5386 (F) Self-ties are of arrays and hashes are not supported in
5387 the current implementation.
5389 =item Semicolon seems to be missing
5391 (W semicolon) A nearby syntax error was probably caused by a missing
5392 semicolon, or possibly some other missing operator, such as a comma.
5394 =item semi-panic: attempt to dup freed string
5396 (S internal) The internal newSVsv() routine was called to duplicate a
5397 scalar that had previously been marked as free.
5399 =item sem%s not implemented
5401 (F) You don't have System V semaphore IPC on your system.
5403 =item send() on closed socket %s
5405 (W closed) The socket you're sending to got itself closed sometime
5406 before now. Check your control flow.
5408 =item Sequence "\c{" invalid
5410 (F) These three characters may not appear in sequence in a
5411 double-quotish context. This message is raised only on non-ASCII
5412 platforms (a different error message is output on ASCII ones). If you
5413 were intending to specify a control character with this sequence, you'll
5414 have to use a different way to specify it.
5416 =item Sequence (? incomplete in regex; marked by S<<-- HERE> in m/%s/
5418 (F) A regular expression ended with an incomplete extension (?. The
5419 S<<-- HERE> shows whereabouts in the regular expression the problem was
5420 discovered. See L<perlre>.
5422 =item Sequence (?%c...) not implemented in regex; marked by S<<-- HERE> in
5425 (F) A proposed regular expression extension has the character reserved
5426 but has not yet been written. The S<<-- HERE> shows whereabouts in the
5427 regular expression the problem was discovered. See L<perlre>.
5429 =item Sequence (?%s...) not recognized in regex; marked by S<<-- HERE> in
5432 (F) You used a regular expression extension that doesn't make sense.
5433 The S<<-- HERE> shows whereabouts in the regular expression the problem was
5434 discovered. This may happen when using the C<(?^...)> construct to tell
5435 Perl to use the default regular expression modifiers, and you
5436 redundantly specify a default modifier. For other
5437 causes, see L<perlre>.
5439 =item Sequence (?#... not terminated in regex m/%s/
5441 (F) A regular expression comment must be terminated by a closing
5442 parenthesis. Embedded parentheses aren't allowed. See
5445 =item Sequence (?&... not terminated in regex; marked by S<<-- HERE> in
5448 (F) A named reference of the form C<(?&...)> was missing the final
5449 closing parenthesis after the name. The S<<-- HERE> shows whereabouts
5450 in the regular expression the problem was discovered.
5452 =item Sequence (?%c... not terminated in regex; marked by S<<-- HERE>
5455 (F) A named group of the form C<(?'...')> or C<< (?<...>) >> was missing the final
5456 closing quote or angle bracket. The S<<-- HERE> shows whereabouts in the
5457 regular expression the problem was discovered.
5459 =item Sequence (?(%c... not terminated in regex; marked by S<<-- HERE>
5462 (F) A named reference of the form C<(?('...')...)> or C<< (?(<...>)...) >> was
5463 missing the final closing quote or angle bracket after the name. The
5464 S<<-- HERE> shows whereabouts in the regular expression the problem was
5467 =item Sequence (?... not terminated in regex; marked by S<<-- HERE> in
5470 (F) There was no matching closing parenthesis for the '('. The
5471 S<<-- HERE> shows whereabouts in the regular expression the problem was
5474 =item Sequence \%s... not terminated in regex; marked by S<<-- HERE> in
5477 (F) The regular expression expects a mandatory argument following the escape
5478 sequence and this has been omitted or incorrectly written.
5480 =item Sequence (?{...}) not terminated with ')'
5482 (F) The end of the perl code contained within the {...} must be
5483 followed immediately by a ')'.
5485 =item Sequence (?PE<gt>... not terminated in regex; marked by S<<-- HERE> in m/%s/
5487 (F) A named reference of the form C<(?PE<gt>...)> was missing the final
5488 closing parenthesis after the name. The S<<-- HERE> shows whereabouts
5489 in the regular expression the problem was discovered.
5491 =item Sequence (?PE<lt>... not terminated in regex; marked by S<<-- HERE> in m/%s/
5493 (F) A named group of the form C<(?PE<lt>...E<gt>')> was missing the final
5494 closing angle bracket. The S<<-- HERE> shows whereabouts in the
5495 regular expression the problem was discovered.
5497 =item Sequence ?P=... not terminated in regex; marked by S<<-- HERE> in
5500 (F) A named reference of the form C<(?P=...)> was missing the final
5501 closing parenthesis after the name. The S<<-- HERE> shows whereabouts
5502 in the regular expression the problem was discovered.
5504 =item Sequence (?R) not terminated in regex m/%s/
5506 (F) An C<(?R)> or C<(?0)> sequence in a regular expression was missing the
5509 =item Z<>500 Server error
5511 (A) This is the error message generally seen in a browser window
5512 when trying to run a CGI program (including SSI) over the web. The
5513 actual error text varies widely from server to server. The most
5514 frequently-seen variants are "500 Server error", "Method (something)
5515 not permitted", "Document contains no data", "Premature end of script
5516 headers", and "Did not produce a valid header".
5518 B<This is a CGI error, not a Perl error>.
5520 You need to make sure your script is executable, is accessible by
5521 the user CGI is running the script under (which is probably not the
5522 user account you tested it under), does not rely on any environment
5523 variables (like PATH) from the user it isn't running under, and isn't
5524 in a location where the CGI server can't find it, basically, more or
5525 less. Please see the following for more information:
5527 http://www.perl.org/CGI_MetaFAQ.html
5528 http://www.htmlhelp.org/faq/cgifaq.html
5529 http://www.w3.org/Security/Faq/
5531 You should also look at L<perlfaq9>.
5533 =item setegid() not implemented
5535 (F) You tried to assign to C<$)>, and your operating system doesn't
5536 support the setegid() system call (or equivalent), or at least Configure
5539 =item seteuid() not implemented
5541 (F) You tried to assign to C<< $> >>, and your operating system doesn't
5542 support the seteuid() system call (or equivalent), or at least Configure
5545 =item setpgrp can't take arguments
5547 (F) Your system has the setpgrp() from BSD 4.2, which takes no
5548 arguments, unlike POSIX setpgid(), which takes a process ID and process
5551 =item setrgid() not implemented
5553 (F) You tried to assign to C<$(>, and your operating system doesn't
5554 support the setrgid() system call (or equivalent), or at least Configure
5557 =item setruid() not implemented
5559 (F) You tried to assign to C<$<>, and your operating system doesn't
5560 support the setruid() system call (or equivalent), or at least Configure
5563 =item setsockopt() on closed socket %s
5565 (W closed) You tried to set a socket option on a closed socket. Did you
5566 forget to check the return value of your socket() call? See
5567 L<perlfunc/setsockopt>.
5569 =item Setting $/ to a reference to %s as a form of slurp is deprecated, treating as undef. This will be fatal in Perl 5.28
5571 (D deprecated) You assigned a reference to a scalar to C<$/> where the
5572 referenced item is not a positive integer. In older perls this B<appeared>
5573 to work the same as setting it to C<undef> but was in fact internally
5574 different, less efficient and with very bad luck could have resulted in
5575 your file being split by a stringified form of the reference.
5577 In Perl 5.20.0 this was changed so that it would be B<exactly> the same as
5578 setting C<$/> to undef, with the exception that this warning would be
5581 You are recommended to change your code to set C<$/> to C<undef> explicitly
5582 if you wish to slurp the file. In Perl 5.28 assigning C<$/> to a
5583 reference to an integer which isn't positive will throw a fatal error.
5585 =item Setting $/ to %s reference is forbidden
5587 (F) You tried to assign a reference to a non integer to C<$/>. In older
5588 Perls this would have behaved similarly to setting it to a reference to
5589 a positive integer, where the integer was the address of the reference.
5590 As of Perl 5.20.0 this is a fatal error, to allow future versions of Perl
5591 to use non-integer refs for more interesting purposes.
5593 =item shm%s not implemented
5595 (F) You don't have System V shared memory IPC on your system.
5597 =item !=~ should be !~
5599 (W syntax) The non-matching operator is !~, not !=~. !=~ will be
5600 interpreted as the != (numeric not equal) and ~ (1's complement)
5601 operators: probably not what you intended.
5603 =item /%s/ should probably be written as "%s"
5605 (W syntax) You have used a pattern where Perl expected to find a string,
5606 as in the first argument to C<join>. Perl will treat the true or false
5607 result of matching the pattern against $_ as the string, which is
5608 probably not what you had in mind.
5610 =item shutdown() on closed socket %s
5612 (W closed) You tried to do a shutdown on a closed socket. Seems a bit
5615 =item SIG%s handler "%s" not defined
5617 (W signal) The signal handler named in %SIG doesn't, in fact, exist.
5618 Perhaps you put it into the wrong package?
5620 =item Slab leaked from cv %p
5622 (S) If you see this message, then something is seriously wrong with the
5623 internal bookkeeping of op trees. An op tree needed to be freed after
5624 a compilation error, but could not be found, so it was leaked instead.
5626 =item sleep(%u) too large
5628 (W overflow) You called C<sleep> with a number that was larger than
5629 it can reliably handle and C<sleep> probably slept for less time than
5632 =item Slurpy parameter not last
5634 (F) In a subroutine signature, you put something after a slurpy (array or
5635 hash) parameter. The slurpy parameter takes all the available arguments,
5636 so there can't be any left to fill later parameters.
5638 =item Smart matching a non-overloaded object breaks encapsulation
5640 (F) You should not use the C<~~> operator on an object that does not
5641 overload it: Perl refuses to use the object's underlying structure
5642 for the smart match.
5644 =item Smartmatch is experimental
5646 (S experimental::smartmatch) This warning is emitted if you
5647 use the smartmatch (C<~~>) operator. This is currently an experimental
5648 feature, and its details are subject to change in future releases of
5649 Perl. Particularly, its current behavior is noticed for being
5650 unnecessarily complex and unintuitive, and is very likely to be
5653 =item sort is now a reserved word
5655 (F) An ancient error message that almost nobody ever runs into anymore.
5656 But before sort was a keyword, people sometimes used it as a filehandle.
5658 =item Source filters apply only to byte streams
5660 (F) You tried to activate a source filter (usually by loading a
5661 source filter module) within a string passed to C<eval>. This is
5662 not permitted under the C<unicode_eval> feature. Consider using
5663 C<evalbytes> instead. See L<feature>.
5665 =item splice() offset past end of array
5667 (W misc) You attempted to specify an offset that was past the end of
5668 the array passed to splice(). Splicing will instead commence at the
5669 end of the array, rather than past it. If this isn't what you want,
5670 try explicitly pre-extending the array by assigning $#array = $offset.
5671 See L<perlfunc/splice>.
5675 (P) The split was looping infinitely. (Obviously, a split shouldn't
5676 iterate more times than there are characters of input, which is what
5677 happened.) See L<perlfunc/split>.
5679 =item Statement unlikely to be reached
5681 (W exec) You did an exec() with some statement after it other than a
5682 die(). This is almost always an error, because exec() never returns
5683 unless there was a failure. You probably wanted to use system()
5684 instead, which does return. To suppress this warning, put the exec() in
5687 =item "state" subroutine %s can't be in a package
5689 (F) Lexically scoped subroutines aren't in a package, so it doesn't make
5690 sense to try to declare one with a package qualifier on the front.
5692 =item "state %s" used in sort comparison
5694 (W syntax) The package variables $a and $b are used for sort comparisons.
5695 You used $a or $b in as an operand to the C<< <=> >> or C<cmp> operator inside a
5696 sort comparison block, and the variable had earlier been declared as a
5697 lexical variable. Either qualify the sort variable with the package
5698 name, or rename the lexical variable.
5700 =item "state" variable %s can't be in a package
5702 (F) Lexically scoped variables aren't in a package, so it doesn't make
5703 sense to try to declare one with a package qualifier on the front. Use
5704 local() if you want to localize a package variable.
5706 =item stat() on unopened filehandle %s
5708 (W unopened) You tried to use the stat() function on a filehandle that
5709 was either never opened or has since been closed.
5711 =item Strings with code points over 0xFF may not be mapped into in-memory file handles
5713 (W utf8) You tried to open a reference to a scalar for read or append
5714 where the scalar contained code points over 0xFF. In-memory files
5715 model on-disk files and can only contain bytes.
5717 =item Stub found while resolving method "%s" overloading "%s" in package "%s"
5719 (P) Overloading resolution over @ISA tree may be broken by importation
5720 stubs. Stubs should never be implicitly created, but explicit calls to
5721 C<can> may break this.
5723 =item Subroutine "&%s" is not available
5725 (W closure) During compilation, an inner named subroutine or eval is
5726 attempting to capture an outer lexical subroutine that is not currently
5727 available. This can happen for one of two reasons. First, the lexical
5728 subroutine may be declared in an outer anonymous subroutine that has
5729 not yet been created. (Remember that named subs are created at compile
5730 time, while anonymous subs are created at run-time.) For example,
5732 sub { my sub a {...} sub f { \&a } }
5734 At the time that f is created, it can't capture the current "a" sub,
5735 since the anonymous subroutine hasn't been created yet. Conversely, the
5736 following won't give a warning since the anonymous subroutine has by now
5737 been created and is live:
5739 sub { my sub a {...} eval 'sub f { \&a }' }->();
5741 The second situation is caused by an eval accessing a lexical subroutine
5742 that has gone out of scope, for example,
5750 Here, when the '\&a' in the eval is being compiled, f() is not currently
5751 being executed, so its &a is not available for capture.
5753 =item "%s" subroutine &%s masks earlier declaration in same %s
5755 (W misc) A "my" or "state" subroutine has been redeclared in the
5756 current scope or statement, effectively eliminating all access to
5757 the previous instance. This is almost always a typographical error.
5758 Note that the earlier subroutine will still exist until the end of
5759 the scope or until all closure references to it are destroyed.
5761 =item Subroutine %s redefined
5763 (W redefine) You redefined a subroutine. To suppress this warning, say
5766 no warnings 'redefine';
5767 eval "sub name { ... }";
5770 =item Subroutine "%s" will not stay shared
5772 (W closure) An inner (nested) I<named> subroutine is referencing a "my"
5773 subroutine defined in an outer named subroutine.
5775 When the inner subroutine is called, it will see the value of the outer
5776 subroutine's lexical subroutine as it was before and during the *first*
5777 call to the outer subroutine; in this case, after the first call to the
5778 outer subroutine is complete, the inner and outer subroutines will no
5779 longer share a common value for the lexical subroutine. In other words,
5780 it will no longer be shared. This will especially make a difference
5781 if the lexical subroutines accesses lexical variables declared in its
5784 This problem can usually be solved by making the inner subroutine
5785 anonymous, using the C<sub {}> syntax. When inner anonymous subs that
5786 reference lexical subroutines in outer subroutines are created, they
5787 are automatically rebound to the current values of such lexical subs.
5789 =item Substitution loop
5791 (P) The substitution was looping infinitely. (Obviously, a substitution
5792 shouldn't iterate more times than there are characters of input, which
5793 is what happened.) See the discussion of substitution in
5794 L<perlop/"Regexp Quote-Like Operators">.
5796 =item Substitution pattern not terminated
5798 (F) The lexer couldn't find the interior delimiter of an s/// or s{}{}
5799 construct. Remember that bracketing delimiters count nesting level.
5800 Missing the leading C<$> from variable C<$s> may cause this error.
5802 =item Substitution replacement not terminated
5804 (F) The lexer couldn't find the final delimiter of an s/// or s{}{}
5805 construct. Remember that bracketing delimiters count nesting level.
5806 Missing the leading C<$> from variable C<$s> may cause this error.
5808 =item substr outside of string
5810 (W substr)(F) You tried to reference a substr() that pointed outside of
5811 a string. That is, the absolute value of the offset was larger than the
5812 length of the string. See L<perlfunc/substr>. This warning is fatal if
5813 substr is used in an lvalue context (as the left hand side of an
5814 assignment or as a subroutine argument for example).
5816 =item sv_upgrade from type %d down to type %d
5818 (P) Perl tried to force the upgrade of an SV to a type which was actually
5819 inferior to its current type.
5821 =item SWASHNEW didn't return an HV ref
5823 (P) Something went wrong internally when Perl was trying to look up
5826 =item Switch (?(condition)... contains too many branches in regex; marked by
5827 S<<-- HERE> in m/%s/
5829 (F) A (?(condition)if-clause|else-clause) construct can have at most
5830 two branches (the if-clause and the else-clause). If you want one or
5831 both to contain alternation, such as using C<this|that|other>, enclose
5832 it in clustering parentheses:
5834 (?(condition)(?:this|that|other)|else-clause)
5836 The S<<-- HERE> shows whereabouts in the regular expression the problem
5837 was discovered. See L<perlre>.
5839 =item Switch condition not recognized in regex; marked by S<<-- HERE> in
5842 (F) The condition part of a (?(condition)if-clause|else-clause) construct
5843 is not known. The condition must be one of the following:
5845 (1) (2) ... true if 1st, 2nd, etc., capture matched
5846 (<NAME>) ('NAME') true if named capture matched
5847 (?=...) (?<=...) true if subpattern matches
5848 (?!...) (?<!...) true if subpattern fails to match
5849 (?{ CODE }) true if code returns a true value
5850 (R) true if evaluating inside recursion
5851 (R1) (R2) ... true if directly inside capture group 1, 2, etc.
5852 (R&NAME) true if directly inside named capture
5853 (DEFINE) always false; for defining named subpatterns
5855 The S<<-- HERE> shows whereabouts in the regular expression the problem was
5856 discovered. See L<perlre>.
5858 =item Switch (?(condition)... not terminated in regex; marked by
5859 S<<-- HERE> in m/%s/
5861 (F) You omitted to close a (?(condition)...) block somewhere
5862 in the pattern. Add a closing parenthesis in the appropriate
5863 position. See L<perlre>.
5865 =item switching effective %s is not implemented
5867 (F) While under the C<use filetest> pragma, we cannot switch the real
5868 and effective uids or gids.
5872 (F) Probably means you had a syntax error. Common reasons include:
5874 A keyword is misspelled.
5875 A semicolon is missing.
5877 An opening or closing parenthesis is missing.
5878 An opening or closing brace is missing.
5879 A closing quote is missing.
5881 Often there will be another error message associated with the syntax
5882 error giving more information. (Sometimes it helps to turn on B<-w>.)
5883 The error message itself often tells you where it was in the line when
5884 it decided to give up. Sometimes the actual error is several tokens
5885 before this, because Perl is good at understanding random input.
5886 Occasionally the line number may be misleading, and once in a blue moon
5887 the only way to figure out what's triggering the error is to call
5888 C<perl -c> repeatedly, chopping away half the program each time to see
5889 if the error went away. Sort of the cybernetic version of S<20 questions>.
5891 =item syntax error at line %d: '%s' unexpected
5893 (A) You've accidentally run your script through the Bourne shell instead
5894 of Perl. Check the #! line, or manually feed your script into Perl
5897 =item syntax error in file %s at line %d, next 2 tokens "%s"
5899 (F) This error is likely to occur if you run a perl5 script through
5900 a perl4 interpreter, especially if the next 2 tokens are "use strict"
5901 or "my $var" or "our $var".
5903 =item Syntax error in (?[...]) in regex m/%s/
5905 (F) Perl could not figure out what you meant inside this construct; this
5906 notifies you that it is giving up trying.
5910 (F) The final summary message when a C<perl -c> succeeds.
5912 =item sysread() on closed filehandle %s
5914 (W closed) You tried to read from a closed filehandle.
5916 =item sysread() on unopened filehandle %s
5918 (W unopened) You tried to read from a filehandle that was never opened.
5920 =item System V %s is not implemented on this machine
5922 (F) You tried to do something with a function beginning with "sem",
5923 "shm", or "msg" but that System V IPC is not implemented in your
5924 machine. In some machines the functionality can exist but be
5925 unconfigured. Consult your system support.
5927 =item syswrite() on closed filehandle %s
5929 (W closed) The filehandle you're writing to got itself closed sometime
5930 before now. Check your control flow.
5932 =item C<-T> and C<-B> not implemented on filehandles
5934 (F) Perl can't peek at the stdio buffer of filehandles when it doesn't
5935 know about your kind of stdio. You'll have to use a filename instead.
5937 =item Target of goto is too deeply nested
5939 (F) You tried to use C<goto> to reach a label that was too deeply nested
5940 for Perl to reach. Perl is doing you a favor by refusing.
5942 =item telldir() attempted on invalid dirhandle %s
5944 (W io) The dirhandle you tried to telldir() is either closed or not really
5945 a dirhandle. Check your control flow.
5947 =item tell() on unopened filehandle
5949 (W unopened) You tried to use the tell() function on a filehandle that
5950 was either never opened or has since been closed.
5952 =item That use of $[ is unsupported
5954 (F) Assignment to C<$[> is now strictly circumscribed, and interpreted
5955 as a compiler directive. You may say only one of
5964 This is to prevent the problem of one module changing the array base out
5965 from under another module inadvertently. See L<perlvar/$[> and L<arybase>.
5967 =item The bitwise feature is experimental
5969 (S experimental::bitwise) This warning is emitted if you use bitwise
5970 operators (C<& | ^ ~ &. |. ^. ~.>) with the "bitwise" feature enabled.
5971 Simply suppress the warning if you want to use the feature, but know
5972 that in doing so you are taking the risk of using an experimental
5973 feature which may change or be removed in a future Perl version:
5975 no warnings "experimental::bitwise";
5976 use feature "bitwise";
5979 =item The crypt() function is unimplemented due to excessive paranoia.
5981 (F) Configure couldn't find the crypt() function on your machine,
5982 probably because your vendor didn't supply it, probably because they
5983 think the U.S. Government thinks it's a secret, or at least that they
5984 will continue to pretend that it is. And if you quote me on that, I
5987 =item The experimental declared_refs feature is not enabled
5989 (F) To declare references to variables, as in C<my \%x>, you must first enable
5992 no warnings "experimental::declared_refs";
5993 use feature "declared_refs";
5995 =item The %s function is unimplemented
5997 (F) The function indicated isn't implemented on this architecture,
5998 according to the probings of Configure.
6000 =item The regex_sets feature is experimental
6002 (S experimental::regex_sets) This warning is emitted if you
6003 use the syntax S<C<(?[ ])>> in a regular expression.
6004 The details of this feature are subject to change.
6005 if you want to use it, but know that in doing so you
6006 are taking the risk of using an experimental feature which may
6007 change in a future Perl version, you can do this to silence the
6010 no warnings "experimental::regex_sets";
6012 =item The signatures feature is experimental
6014 (S experimental::signatures) This warning is emitted if you unwrap a
6015 subroutine's arguments using a signature. Simply suppress the warning
6016 if you want to use the feature, but know that in doing so you are taking
6017 the risk of using an experimental feature which may change or be removed
6018 in a future Perl version:
6020 no warnings "experimental::signatures";
6021 use feature "signatures";
6022 sub foo ($left, $right) { ... }
6024 =item The stat preceding %s wasn't an lstat
6026 (F) It makes no sense to test the current stat buffer for symbolic
6027 linkhood if the last stat that wrote to the stat buffer already went
6028 past the symlink to get to the real file. Use an actual filename
6031 =item The 'unique' attribute may only be applied to 'our' variables
6033 (F) This attribute was never supported on C<my> or C<sub> declarations.
6035 =item This Perl can't reset CRTL environ elements (%s)
6037 =item This Perl can't set CRTL environ elements (%s=%s)
6039 (W internal) Warnings peculiar to VMS. You tried to change or delete an
6040 element of the CRTL's internal environ array, but your copy of Perl
6041 wasn't built with a CRTL that contained the setenv() function. You'll
6042 need to rebuild Perl with a CRTL that does, or redefine
6043 F<PERL_ENV_TABLES> (see L<perlvms>) so that the environ array isn't the
6044 target of the change to
6045 %ENV which produced the warning.
6047 =item This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().
6049 (F) Something has attempted to use an internal API call which
6050 depends on Perl being compiled with the default support for randomized hash
6051 key traversal, but this Perl has been compiled without it. You should
6052 report this warning to the relevant upstream party, or recompile perl
6053 with default options.
6055 =item times not implemented
6057 (F) Your version of the C library apparently doesn't do times(). I
6058 suspect you're not running on Unix.
6060 =item "-T" is on the #! line, it must also be used on the command line
6062 (X) The #! line (or local equivalent) in a Perl script contains
6063 the B<-T> option (or the B<-t> option), but Perl was not invoked with
6064 B<-T> in its command line. This is an error because, by the time
6065 Perl discovers a B<-T> in a script, it's too late to properly taint
6066 everything from the environment. So Perl gives up.
6068 If the Perl script is being executed as a command using the #!
6069 mechanism (or its local equivalent), this error can usually be
6070 fixed by editing the #! line so that the B<-%c> option is a part of
6071 Perl's first argument: e.g. change C<perl -n -%c> to C<perl -%c -n>.
6073 If the Perl script is being executed as C<perl scriptname>, then the
6074 B<-%c> option must appear on the command line: C<perl -%c scriptname>.
6076 =item To%s: illegal mapping '%s'
6078 (F) You tried to define a customized To-mapping for lc(), lcfirst,
6079 uc(), or ucfirst() (or their string-inlined versions), but you
6080 specified an illegal mapping.
6081 See L<perlunicode/"User-Defined Character Properties">.
6083 =item Too deeply nested ()-groups
6085 (F) Your template contains ()-groups with a ridiculously deep nesting level.
6087 =item Too few args to syscall
6089 (F) There has to be at least one argument to syscall() to specify the
6090 system call to call, silly dilly.
6092 =item Too few arguments for subroutine
6094 (F) A subroutine using a signature received too few arguments than
6095 required by the signature. The caller of the subroutine is presumably
6098 =item Too late for "-%s" option
6100 (X) The #! line (or local equivalent) in a Perl script contains the
6101 B<-M>, B<-m> or B<-C> option.
6103 In the case of B<-M> and B<-m>, this is an error because those options
6104 are not intended for use inside scripts. Use the C<use> pragma instead.
6106 The B<-C> option only works if it is specified on the command line as
6107 well (with the same sequence of letters or numbers following). Either
6108 specify this option on the command line, or, if your system supports
6109 it, make your script executable and run it directly instead of passing
6112 =item Too late to run %s block
6114 (W void) A CHECK or INIT block is being defined during run time proper,
6115 when the opportunity to run them has already passed. Perhaps you are
6116 loading a file with C<require> or C<do> when you should be using C<use>
6117 instead. Or perhaps you should put the C<require> or C<do> inside a
6120 =item Too many args to syscall
6122 (F) Perl supports a maximum of only 14 args to syscall().
6124 =item Too many arguments for %s
6126 (F) The function requires fewer arguments than you specified.
6128 =item Too many arguments for subroutine
6130 (F) A subroutine using a signature received too many arguments than
6131 required by the signature. The caller of the subroutine is presumably
6137 (A) You've accidentally run your script through B<csh> instead of Perl.
6138 Check the #! line, or manually feed your script into Perl yourself.
6142 (A) You've accidentally run your script through B<csh> instead of Perl.
6143 Check the #! line, or manually feed your script into Perl yourself.
6145 =item Trailing \ in regex m/%s/
6147 (F) The regular expression ends with an unbackslashed backslash.
6148 Backslash it. See L<perlre>.
6150 =item Transliteration pattern not terminated
6152 (F) The lexer couldn't find the interior delimiter of a tr/// or tr[][]
6153 or y/// or y[][] construct. Missing the leading C<$> from variables
6154 C<$tr> or C<$y> may cause this error.
6156 =item Transliteration replacement not terminated
6158 (F) The lexer couldn't find the final delimiter of a tr///, tr[][],
6159 y/// or y[][] construct.
6161 =item '%s' trapped by operation mask
6163 (F) You tried to use an operator from a Safe compartment in which it's
6164 disallowed. See L<Safe>.
6166 =item truncate not implemented
6168 (F) Your machine doesn't implement a file truncation mechanism that
6169 Configure knows about.
6171 =item Type of arg %d to &CORE::%s must be %s
6173 (F) The subroutine in question in the CORE package requires its argument
6174 to be a hard reference to data of the specified type. Overloading is
6175 ignored, so a reference to an object that is not the specified type, but
6176 nonetheless has overloading to handle it, will still not be accepted.
6178 =item Type of arg %d to %s must be %s (not %s)
6180 (F) This function requires the argument in that position to be of a
6181 certain type. Arrays must be @NAME or C<@{EXPR}>. Hashes must be
6182 %NAME or C<%{EXPR}>. No implicit dereferencing is allowed--use the
6183 {EXPR} forms as an explicit dereference. See L<perlref>.
6185 =item umask not implemented
6187 (F) Your machine doesn't implement the umask function and you tried to
6188 use it to restrict permissions for yourself (EXPR & 0700).
6190 =item Unbalanced context: %d more PUSHes than POPs
6192 (S internal) The exit code detected an internal inconsistency in how
6193 many execution contexts were entered and left.
6195 =item Unbalanced saves: %d more saves than restores
6197 (S internal) The exit code detected an internal inconsistency in how
6198 many values were temporarily localized.
6200 =item Unbalanced scopes: %d more ENTERs than LEAVEs
6202 (S internal) The exit code detected an internal inconsistency in how
6203 many blocks were entered and left.
6205 =item Unbalanced string table refcount: (%d) for "%s"
6207 (S internal) On exit, Perl found some strings remaining in the shared
6208 string table used for copy on write and for hash keys. The entries
6209 should have been freed, so this indicates a bug somewhere.
6211 =item Unbalanced tmps: %d more allocs than frees
6213 (S internal) The exit code detected an internal inconsistency in how
6214 many mortal scalars were allocated and freed.
6216 =item Undefined format "%s" called
6218 (F) The format indicated doesn't seem to exist. Perhaps it's really in
6219 another package? See L<perlform>.
6221 =item Undefined sort subroutine "%s" called
6223 (F) The sort comparison routine specified doesn't seem to exist.
6224 Perhaps it's in a different package? See L<perlfunc/sort>.
6226 =item Undefined subroutine &%s called
6228 (F) The subroutine indicated hasn't been defined, or if it was, it has
6229 since been undefined.
6231 =item Undefined subroutine called
6233 (F) The anonymous subroutine you're trying to call hasn't been defined,
6234 or if it was, it has since been undefined.
6236 =item Undefined subroutine in sort
6238 (F) The sort comparison routine specified is declared but doesn't seem
6239 to have been defined yet. See L<perlfunc/sort>.
6241 =item Undefined top format "%s" called
6243 (F) The format indicated doesn't seem to exist. Perhaps it's really in
6244 another package? See L<perlform>.
6246 =item Undefined value assigned to typeglob
6248 (W misc) An undefined value was assigned to a typeglob, a la
6249 C<*foo = undef>. This does nothing. It's possible that you really mean
6252 =item %s: Undefined variable
6254 (A) You've accidentally run your script through B<csh> instead of Perl.
6255 Check the #! line, or manually feed your script into Perl yourself.
6257 =item Unescaped left brace in regex is deprecated here (and will be fatal in Perl 5.30), passed through in regex; marked by S<<-- HERE> in m/%s/
6259 (D deprecated, regexp) The simple rule to remember, if you want to
6260 match a literal C<{> character (U+007B C<LEFT CURLY BRACKET>) in a
6261 regular expression pattern, is to escape each literal instance of it in
6262 some way. Generally easiest is to precede it with a backslash, like
6263 C<\{> or enclose it in square brackets (C<[{]>). If the pattern
6264 delimiters are also braces, any matching right brace (C<}>) should
6265 also be escaped to avoid confusing the parser, for example,
6269 Forcing literal C<{> characters to be escaped will enable the Perl
6270 language to be extended in various ways in future releases. To avoid
6271 needlessly breaking existing code, the restriction is is not enforced in
6272 contexts where there are unlikely to ever be extensions that could
6273 conflict with the use there of C<{> as a literal.
6275 In this release of Perl, some literal uses of C<{> are fatal, and some
6276 still just deprecated. This is because of an oversight: some uses of a
6277 literal C<{> that should have raised a deprecation warning starting in
6278 v5.20 did not warn until v5.26. By making the already-warned uses fatal
6279 now, some of the planned extensions can be made to the language sooner.
6280 The cases which are still allowed will be fatal in Perl 5.30.
6282 The contexts where no warnings or errors are raised are:
6288 as the first character in a pattern, or following C<^> indicating to
6289 anchor the match to the beginning of a line.
6293 as the first character following a C<|> indicating alternation.
6297 as the first character in a parenthesized grouping like
6304 as the first character following a quantifier
6311 The text of the message above is duplicated below to allow splain (and
6312 'use diagnostics') to work. Since one is fatal, and one not, they can't
6313 be combined as one message. And since the non-fatal one is temporary,
6314 there's no real need to enhance perldiag to handle this transient case.
6316 =item Unescaped left brace in regex is illegal here in regex;
6317 marked by S<<-- HERE> in m/%s/
6319 (F) The simple rule to remember, if you want to
6320 match a literal C<"{"> character (U+007B C<LEFT CURLY BRACKET>) in a
6321 regular expression pattern, is to escape each literal instance of it in
6322 some way. Generally easiest is to precede it with a backslash, like
6323 C<"\{"> or enclose it in square brackets (C<"[{]">). If the pattern
6324 delimiters are also braces, any matching right brace (C<"}">) should
6325 also be escaped to avoid confusing the parser, for example,
6329 Forcing literal C<"{"> characters to be escaped will enable the Perl
6330 language to be extended in various ways in future releases. To avoid
6331 needlessly breaking existing code, the restriction is is not enforced in
6332 contexts where there are unlikely to ever be extensions that could
6333 conflict with the use there of C<"{"> as a literal.
6335 In this release of Perl, some literal uses of C<"{"> are fatal, and some
6336 still just deprecated. This is because of an oversight: some uses of a
6337 literal C<"{"> that should have raised a deprecation warning starting in
6338 v5.20 did not warn until v5.26. By making the already-warned uses fatal
6339 now, some of the planned extensions can be made to the language sooner.
6341 The contexts where no warnings or errors are raised are:
6347 as the first character in a pattern, or following C<"^"> indicating to
6348 anchor the match to the beginning of a line.
6352 as the first character following a C<"|"> indicating alternation.
6356 as the first character in a parenthesized grouping like
6363 as the first character following a quantifier
6369 =item Unescaped literal '%c' in regex; marked by <-- HERE in m/%s/
6371 (W regexp) (only under C<S<use re 'strict'>>)
6373 Within the scope of C<S<use re 'strict'>> in a regular expression
6374 pattern, you included an unescaped C<}> or C<]> which was interpreted
6375 literally. These two characters are sometimes metacharacters, and
6376 sometimes literals, depending on what precedes them in the
6377 pattern. This is unlike the similar C<)> which is always a
6378 metacharacter unless escaped.
6380 This action at a distance, perhaps a large distance, can lead to Perl
6381 silently misinterpreting what you meant, so when you specify that you
6382 want extra checking by C<S<use re 'strict'>>, this warning is generated.
6383 If you meant the character as a literal, simply confirm that to Perl by
6384 preceding the character with a backslash, or make it into a bracketed
6385 character class (like C<[}]>). If you meant it as closing a
6386 corresponding C<[> or C<{>, you'll need to look back through the pattern
6387 to find out why that isn't happening.
6389 =item unexec of %s into %s failed!
6391 (F) The unexec() routine failed for some reason. See your local FSF
6392 representative, who probably put it there in the first place.
6394 =item Unexpected binary operator '%c' with no preceding operand in regex;
6395 marked by S<<-- HERE> in m/%s/
6397 (F) You had something like this:
6401 where the C<"|"> is a binary operator with an operand on the right, but
6402 no operand on the left.
6404 =item Unexpected character in regex; marked by S<<-- HERE> in m/%s/
6406 (F) You had something like this:
6410 Within C<(?[ ])>, no literal characters are allowed unless they are
6411 within an inner pair of square brackets, like
6415 Another possibility is that you forgot a backslash. Perl isn't smart
6416 enough to figure out what you really meant.
6418 =item Unexpected constant lvalue entersub entry via type/targ %d:%d
6420 (P) When compiling a subroutine call in lvalue context, Perl failed an
6421 internal consistency check. It encountered a malformed op tree.
6423 =item Unexpected exit %u
6425 (S) exit() was called or the script otherwise finished gracefully when
6426 C<PERL_EXIT_WARN> was set in C<PL_exit_flags>.
6428 =item Unexpected exit failure %d
6430 (S) An uncaught die() was called when C<PERL_EXIT_WARN> was set in
6433 =item Unexpected ')' in regex; marked by S<<-- HERE> in m/%s/
6435 (F) You had something like this:
6437 (?[ ( \p{Digit} + ) ])
6439 The C<")"> is out-of-place. Something apparently was supposed to
6440 be combined with the digits, or the C<"+"> shouldn't be there, or
6441 something like that. Perl can't figure out what was intended.
6443 =item Unexpected '(' with no preceding operator in regex; marked by
6444 S<<-- HERE> in m/%s/
6446 (F) You had something like this:
6448 (?[ \p{Digit} ( \p{Lao} + \p{Thai} ) ])
6450 There should be an operator before the C<"(">, as there's
6451 no indication as to how the digits are to be combined
6452 with the characters in the Lao and Thai scripts.
6454 =item Unicode non-character U+%X is not recommended for open interchange
6456 (S nonchar) Certain codepoints, such as U+FFFE and U+FFFF, are
6457 defined by the Unicode standard to be non-characters. Those
6458 are legal codepoints, but are reserved for internal use; so,
6459 applications shouldn't attempt to exchange them. An application
6460 may not be expecting any of these characters at all, and receiving
6461 them may lead to bugs. If you know what you are doing you can
6462 turn off this warning by C<no warnings 'nonchar';>.
6464 This is not really a "severe" error, but it is supposed to be
6465 raised by default even if warnings are not enabled, and currently
6466 the only way to do that in Perl is to mark it as serious.
6468 =item Unicode surrogate U+%X is illegal in UTF-8
6470 (S surrogate) You had a UTF-16 surrogate in a context where they are
6471 not considered acceptable. These code points, between U+D800 and
6472 U+DFFF (inclusive), are used by Unicode only for UTF-16. However, Perl
6473 internally allows all unsigned integer code points (up to the size limit
6474 available on your platform), including surrogates. But these can cause
6475 problems when being input or output, which is likely where this message
6476 came from. If you really really know what you are doing you can turn
6477 off this warning by C<no warnings 'surrogate';>.
6479 =item Unknown charname '%s'
6481 (F) The name you used inside C<\N{}> is unknown to Perl. Check the
6482 spelling. You can say C<use charnames ":loose"> to not have to be
6483 so precise about spaces, hyphens, and capitalization on standard Unicode
6484 names. (Any custom aliases that have been created must be specified
6485 exactly, regardless of whether C<:loose> is used or not.) This error may
6486 also happen if the C<\N{}> is not in the scope of the corresponding
6487 C<S<use charnames>>.
6489 =item Unknown charname '' is deprecated. Its use will be fatal in Perl 5.28
6491 (D deprecated) You had a C<\N{}> with nothing between the braces. This
6492 usage was deprecated in Perl 5.24, and will be made a syntax error in
6497 (P) Perl was about to print an error message in C<$@>, but the C<$@> variable
6498 did not exist, even after an attempt to create it.
6500 =item Unknown open() mode '%s'
6502 (F) The second argument of 3-argument open() is not among the list
6503 of valid modes: C<< < >>, C<< > >>, C<<< >> >>>, C<< +< >>,
6504 C<< +> >>, C<<< +>> >>>, C<-|>, C<|->, C<< <& >>, C<< >& >>.
6506 =item Unknown PerlIO layer "%s"
6508 (W layer) An attempt was made to push an unknown layer onto the Perl I/O
6509 system. (Layers take care of transforming data between external and
6510 internal representations.) Note that some layers, such as C<mmap>,
6511 are not supported in all environments. If your program didn't
6512 explicitly request the failing operation, it may be the result of the
6513 value of the environment variable PERLIO.
6515 =item Unknown process %x sent message to prime_env_iter: %s
6517 (P) An error peculiar to VMS. Perl was reading values for %ENV before
6518 iterating over it, and someone else stuck a message in the stream of
6519 data Perl expected. Someone's very confused, or perhaps trying to
6520 subvert Perl's population of %ENV for nefarious purposes.
6522 =item Unknown regex modifier "%s"
6524 (F) Alphanumerics immediately following the closing delimiter
6525 of a regular expression pattern are interpreted by Perl as modifier
6526 flags for the regex. One of the ones you specified is invalid. One way
6527 this can happen is if you didn't put in white space between the end of
6528 the regex and a following alphanumeric operator:
6530 if ($a =~ /foo/and $bar == 3) { ... }
6532 The C<"a"> is a valid modifier flag, but the C<"n"> is not, and raises
6533 this error. Likely what was meant instead was:
6535 if ($a =~ /foo/ and $bar == 3) { ... }
6537 =item Unknown "re" subpragma '%s' (known ones are: %s)
6539 (W) You tried to use an unknown subpragma of the "re" pragma.
6541 =item Unknown switch condition (?(...)) in regex; marked by S<<-- HERE> in
6544 (F) The condition part of a (?(condition)if-clause|else-clause) construct
6545 is not known. The condition must be one of the following:
6547 (1) (2) ... true if 1st, 2nd, etc., capture matched
6548 (<NAME>) ('NAME') true if named capture matched
6549 (?=...) (?<=...) true if subpattern matches
6550 (?!...) (?<!...) true if subpattern fails to match
6551 (?{ CODE }) true if code returns a true value
6552 (R) true if evaluating inside recursion
6553 (R1) (R2) ... true if directly inside capture group 1, 2, etc.
6554 (R&NAME) true if directly inside named capture
6555 (DEFINE) always false; for defining named subpatterns
6557 The S<<-- HERE> shows whereabouts in the regular expression the problem was
6558 discovered. See L<perlre>.
6560 =item Unknown Unicode option letter '%c'
6562 (F) You specified an unknown Unicode option. See L<perlrun> documentation
6563 of the C<-C> switch for the list of known options.
6565 =item Unknown Unicode option value %d
6567 (F) You specified an unknown Unicode option. See L<perlrun> documentation
6568 of the C<-C> switch for the list of known options.
6570 =item Unknown verb pattern '%s' in regex; marked by S<<-- HERE> in m/%s/
6572 (F) You either made a typo or have incorrectly put a C<*> quantifier
6573 after an open brace in your pattern. Check the pattern and review
6574 L<perlre> for details on legal verb patterns.
6576 =item Unknown warnings category '%s'
6578 (F) An error issued by the C<warnings> pragma. You specified a warnings
6579 category that is unknown to perl at this point.
6581 Note that if you want to enable a warnings category registered by a
6582 module (e.g. C<use warnings 'File::Find'>), you must have loaded this
6585 =item Unmatched [ in regex; marked by S<<-- HERE> in m/%s/
6587 (F) The brackets around a character class must match. If you wish to
6588 include a closing bracket in a character class, backslash it or put it
6589 first. The S<<-- HERE> shows whereabouts in the regular expression the
6590 problem was discovered. See L<perlre>.
6592 =item Unmatched ( in regex; marked by S<<-- HERE> in m/%s/
6594 =item Unmatched ) in regex; marked by S<<-- HERE> in m/%s/
6596 (F) Unbackslashed parentheses must always be balanced in regular
6597 expressions. If you're a vi user, the % key is valuable for finding
6598 the matching parenthesis. The S<<-- HERE> shows whereabouts in the
6599 regular expression the problem was discovered. See L<perlre>.
6601 =item Unmatched right %s bracket
6603 (F) The lexer counted more closing curly or square brackets than opening
6604 ones, so you're probably missing a matching opening bracket. As a
6605 general rule, you'll find the missing one (so to speak) near the place
6606 you were last editing.
6608 =item Unquoted string "%s" may clash with future reserved word
6610 (W reserved) You used a bareword that might someday be claimed as a
6611 reserved word. It's best to put such a word in quotes, or capitalize it
6612 somehow, or insert an underbar into it. You might also declare it as a
6615 =item Unrecognized character %s; marked by S<<-- HERE> after %s near column
6618 (F) The Perl parser has no idea what to do with the specified character
6619 in your Perl script (or eval) near the specified column. Perhaps you
6620 tried to run a compressed script, a binary program, or a directory as
6623 =item Unrecognized escape \%c in character class in regex; marked by
6624 S<<-- HERE> in m/%s/
6626 (F) You used a backslash-character combination which is not
6627 recognized by Perl inside character classes. This is a fatal
6628 error when the character class is used within C<(?[ ])>.
6630 =item Unrecognized escape \%c in character class passed through in regex;
6631 marked by S<<-- HERE> in m/%s/
6633 (W regexp) You used a backslash-character combination which is not
6634 recognized by Perl inside character classes. The character was
6635 understood literally, but this may change in a future version of Perl.
6636 The S<<-- HERE> shows whereabouts in the regular expression the
6637 escape was discovered.
6639 =item Unrecognized escape \%c passed through
6641 (W misc) You used a backslash-character combination which is not
6642 recognized by Perl. The character was understood literally, but this may
6643 change in a future version of Perl.
6645 =item Unrecognized escape \%s passed through in regex; marked by
6646 S<<-- HERE> in m/%s/
6648 (W regexp) You used a backslash-character combination which is not
6649 recognized by Perl. The character(s) were understood literally, but
6650 this may change in a future version of Perl. The S<<-- HERE> shows
6651 whereabouts in the regular expression the escape was discovered.
6653 =item Unrecognized signal name "%s"
6655 (F) You specified a signal name to the kill() function that was not
6656 recognized. Say C<kill -l> in your shell to see the valid signal names
6659 =item Unrecognized switch: -%s (-h will show valid options)
6661 (F) You specified an illegal option to Perl. Don't do that. (If you
6662 think you didn't do that, check the #! line to see if it's supplying the
6663 bad switch on your behalf.)
6665 =item Unsuccessful %s on filename containing newline
6667 (W newline) A file operation was attempted on a filename, and that
6668 operation failed, PROBABLY because the filename contained a newline,
6669 PROBABLY because you forgot to chomp() it off. See L<perlfunc/chomp>.
6671 =item Unsupported directory function "%s" called
6673 (F) Your machine doesn't support opendir() and readdir().
6675 =item Unsupported function %s
6677 (F) This machine doesn't implement the indicated function, apparently.
6678 At least, Configure doesn't think so.
6680 =item Unsupported function fork
6682 (F) Your version of executable does not support forking.
6684 Note that under some systems, like OS/2, there may be different flavors
6685 of Perl executables, some of which may support fork, some not. Try
6686 changing the name you call Perl by to C<perl_>, C<perl__>, and so on.
6688 =item Unsupported script encoding %s
6690 (F) Your program file begins with a Unicode Byte Order Mark (BOM) which
6691 declares it to be in a Unicode encoding that Perl cannot read.
6693 =item Unsupported socket function "%s" called
6695 (F) Your machine doesn't support the Berkeley socket mechanism, or at
6696 least that's what Configure thought.
6698 =item Unterminated attribute list
6700 (F) The lexer found something other than a simple identifier at the
6701 start of an attribute, and it wasn't a semicolon or the start of a
6702 block. Perhaps you terminated the parameter list of the previous
6703 attribute too soon. See L<attributes>.
6705 =item Unterminated attribute parameter in attribute list
6707 (F) The lexer saw an opening (left) parenthesis character while parsing
6708 an attribute list, but the matching closing (right) parenthesis
6709 character was not found. You may need to add (or remove) a backslash
6710 character to get your parentheses to balance. See L<attributes>.
6712 =item Unterminated compressed integer
6714 (F) An argument to unpack("w",...) was incompatible with the BER
6715 compressed integer format and could not be converted to an integer.
6716 See L<perlfunc/pack>.
6718 =item Unterminated delimiter for here document
6720 (F) This message occurs when a here document label has an initial
6721 quotation mark but the final quotation mark is missing. Perhaps
6730 =item Unterminated \g... pattern in regex; marked by S<<-- HERE> in m/%s/
6732 =item Unterminated \g{...} pattern in regex; marked by S<<-- HERE> in m/%s/
6734 (F) In a regular expression, you had a C<\g> that wasn't followed by a
6735 proper group reference. In the case of C<\g{>, the closing brace is
6736 missing; otherwise the C<\g> must be followed by an integer. Fix the
6739 =item Unterminated <> operator
6741 (F) The lexer saw a left angle bracket in a place where it was expecting
6742 a term, so it's looking for the corresponding right angle bracket, and
6743 not finding it. Chances are you left some needed parentheses out
6744 earlier in the line, and you really meant a "less than".
6746 =item Unterminated verb pattern argument in regex; marked by S<<-- HERE> in
6749 (F) You used a pattern of the form C<(*VERB:ARG)> but did not terminate
6750 the pattern with a C<)>. Fix the pattern and retry.
6752 =item Unterminated verb pattern in regex; marked by S<<-- HERE> in m/%s/
6754 (F) You used a pattern of the form C<(*VERB)> but did not terminate
6755 the pattern with a C<)>. Fix the pattern and retry.
6757 =item untie attempted while %d inner references still exist
6759 (W untie) A copy of the object returned from C<tie> (or C<tied>) was
6760 still valid when C<untie> was called.
6762 =item Usage: POSIX::%s(%s)
6764 (F) You called a POSIX function with incorrect arguments.
6765 See L<POSIX/FUNCTIONS> for more information.
6767 =item Usage: Win32::%s(%s)
6769 (F) You called a Win32 function with incorrect arguments.
6770 See L<Win32> for more information.
6772 =item $[ used in %s (did you mean $] ?)
6774 (W syntax) You used C<$[> in a comparison, such as:
6780 You probably meant to use C<$]> instead. C<$[> is the base for indexing
6781 arrays. C<$]> is the Perl version number in decimal.
6783 =item Use "%s" instead of "%s"
6785 (F) The second listed construct is no longer legal. Use the first one
6788 =item Useless assignment to a temporary
6790 (W misc) You assigned to an lvalue subroutine, but what
6791 the subroutine returned was a temporary scalar about to
6792 be discarded, so the assignment had no effect.
6794 =item Useless (?-%s) - don't use /%s modifier in regex; marked by
6795 S<<-- HERE> in m/%s/
6797 (W regexp) You have used an internal modifier such as (?-o) that has no
6798 meaning unless removed from the entire regexp:
6800 if ($string =~ /(?-o)$pattern/o) { ... }
6804 if ($string =~ /$pattern/) { ... }
6806 The S<<-- HERE> shows whereabouts in the regular expression the problem was
6807 discovered. See L<perlre>.
6809 =item Useless localization of %s
6811 (W syntax) The localization of lvalues such as C<local($x=10)> is legal,
6812 but in fact the local() currently has no effect. This may change at
6813 some point in the future, but in the meantime such code is discouraged.
6815 =item Useless (?%s) - use /%s modifier in regex; marked by S<<-- HERE> in
6818 (W regexp) You have used an internal modifier such as (?o) that has no
6819 meaning unless applied to the entire regexp:
6821 if ($string =~ /(?o)$pattern/) { ... }
6825 if ($string =~ /$pattern/o) { ... }
6827 The S<<-- HERE> shows whereabouts in the regular expression the problem was
6828 discovered. See L<perlre>.
6830 =item Useless use of attribute "const"
6832 (W misc) The C<const> attribute has no effect except
6833 on anonymous closure prototypes. You applied it to
6834 a subroutine via L<attributes.pm|attributes>. This is only useful
6835 inside an attribute handler for an anonymous subroutine.
6837 =item Useless use of /d modifier in transliteration operator
6839 (W misc) You have used the /d modifier where the searchlist has the
6840 same length as the replacelist. See L<perlop> for more information
6841 about the /d modifier.
6843 =item Useless use of \E
6845 (W misc) You have a \E in a double-quotish string without a C<\U>,
6846 C<\L> or C<\Q> preceding it.
6848 =item Useless use of greediness modifier '%c' in regex; marked by S<<-- HERE> in m/%s/
6850 (W regexp) You specified something like these:
6855 The C<"?"> and C<"+"> don't have any effect, as they modify whether to
6856 match more or fewer when there is a choice, and by specifying to match
6857 exactly a given numer, there is no room left for a choice.
6859 =item Useless use of %s in void context
6861 (W void) You did something without a side effect in a context that does
6862 nothing with the return value, such as a statement that doesn't return a
6863 value from a block, or the left side of a scalar comma operator. Very
6864 often this points not to stupidity on your part, but a failure of Perl
6865 to parse your program the way you thought it would. For example, you'd
6866 get this if you mixed up your C precedence with Python precedence and
6871 when you meant to say
6873 ($one, $two) = (1, 2);
6875 Another common error is to use ordinary parentheses to construct a list
6876 reference when you should be using square or curly brackets, for
6881 when you should have said
6885 The square brackets explicitly turn a list value into a scalar value,
6886 while parentheses do not. So when a parenthesized list is evaluated in
6887 a scalar context, the comma is treated like C's comma operator, which
6888 throws away the left argument, which is not what you want. See
6889 L<perlref> for more on this.
6891 This warning will not be issued for numerical constants equal to 0 or 1
6892 since they are often used in statements like
6894 1 while sub_with_side_effects();
6896 String constants that would normally evaluate to 0 or 1 are warned
6899 =item Useless use of (?-p) in regex; marked by S<<-- HERE> in m/%s/
6901 (W regexp) The C<p> modifier cannot be turned off once set. Trying to do
6904 =item Useless use of "re" pragma
6906 (W) You did C<use re;> without any arguments. That isn't very useful.
6908 =item Useless use of sort in scalar context
6910 (W void) You used sort in scalar context, as in :
6914 This is not very useful, and perl currently optimizes this away.
6916 =item Useless use of %s with no values
6918 (W syntax) You used the push() or unshift() function with no arguments
6919 apart from the array, like C<push(@x)> or C<unshift(@foo)>. That won't
6920 usually have any effect on the array, so is completely useless. It's
6921 possible in principle that push(@tied_array) could have some effect
6922 if the array is tied to a class which implements a PUSH method. If so,
6923 you can write it as C<push(@tied_array,())> to avoid this warning.
6925 =item "use" not allowed in expression
6927 (F) The "use" keyword is recognized and executed at compile time, and
6928 returns no useful value. See L<perlmod>.
6930 =item Use of assignment to $[ is deprecated
6932 (D deprecated) The C<$[> variable (index of the first element in an array)
6933 is deprecated. See L<perlvar/"$[">.
6935 =item Use of bare << to mean <<"" is deprecated. Its use will be fatal in Perl 5.28
6937 (D deprecated) You are now encouraged to use the explicitly quoted
6938 form if you wish to use an empty line as the terminator of the
6941 Use of a bare terminator was deprecated in Perl 5.000, and
6942 will be a fatal error in Perl 5.28.
6944 =item Use of /c modifier is meaningless in s///
6946 (W regexp) You used the /c modifier in a substitution. The /c
6947 modifier is not presently meaningful in substitutions.
6949 =item Use of /c modifier is meaningless without /g
6951 (W regexp) You used the /c modifier with a regex operand, but didn't
6952 use the /g modifier. Currently, /c is meaningful only when /g is
6953 used. (This may change in the future.)
6955 =item Use of code point 0x%s is deprecated; the permissible max is 0x%s. This will be fatal in Perl 5.28
6957 (D deprecated) You used a code point that will not be allowed in a
6958 future perl version, because it is too large. Unicode only allows code
6959 points up to 0x10FFFF, but Perl allows much larger ones. However, the
6960 largest possible ones break the perl interpreter in some constructs,
6961 including causing it to hang in a few cases. The known problem areas
6962 are in C<tr///>, regular expression pattern matching using quantifiers,
6963 as quote delimiters in C<qI<X>...I<X>> (where I<X> is the C<chr()> of a large
6964 code point), and as the upper limits in loops.
6965 There may be other breakages as well. If you get this warning, and
6966 things aren't working correctly, you probably have found one of these.
6968 If your code is to run on various platforms, keep in mind that the upper
6969 limit depends on the platform. It is much larger on 64-bit word sizes
6972 The use of out of range code points was deprecated in Perl 5.24, and
6973 it will be a fatal error in Perl 5.28.
6975 =item Use of comma-less variable list is deprecated. Its use will be fatal in Perl 5.28
6977 (D deprecated) The values you give to a format should be
6978 separated by commas, not just aligned on a line.
6980 This usage will be fatal in Perl 5.28.
6982 =item Use of each() on hash after insertion without resetting hash iterator results in undefined behavior
6984 (S internal) The behavior of C<each()> after insertion is undefined;
6985 it may skip items, or visit items more than once. Consider using
6986 C<keys()> instead of C<each()>.
6988 =item Infinite recursion via empty pattern
6990 (F) You tried to use the empty pattern inside of a regex code block,
6991 for instance C</(?{ s!!! })/>, which resulted in re-executing
6992 the same pattern, which is an infinite loop which is broken by
6993 throwing an exception.
6995 =item Use of := for an empty attribute list is not allowed
6997 (F) The construction C<my $x := 42> used to parse as equivalent to
6998 C<my $x : = 42> (applying an empty attribute list to C<$x>).
6999 This construct was deprecated in 5.12.0, and has now been made a syntax
7000 error, so C<:=> can be reclaimed as a new operator in the future.
7002 If you need an empty attribute list, for example in a code generator, add
7003 a space before the C<=>.
7005 =item Use of %s for non-UTF-8 locale is wrong. Assuming a UTF-8 locale
7007 (W locale) You are matching a regular expression using locale rules,
7008 and the specified construct was encountered. This construct is only
7009 valid for UTF-8 locales, which the current locale isn't. This doesn't
7010 make sense. Perl will continue, assuming a Unicode (UTF-8) locale, but
7011 the results are likely to be wrong.
7013 =item Use of freed value in iteration
7015 (F) Perhaps you modified the iterated array within the loop?
7016 This error is typically caused by code like the following:
7019 @a = () for (1,2,@a);
7021 You are not supposed to modify arrays while they are being iterated over.
7022 For speed and efficiency reasons, Perl internally does not do full
7023 reference-counting of iterated items, hence deleting such an item in the
7024 middle of an iteration causes Perl to see a freed value.
7026 =item Use of /g modifier is meaningless in split
7028 (W regexp) You used the /g modifier on the pattern for a C<split>
7029 operator. Since C<split> always tries to match the pattern
7030 repeatedly, the C</g> has no effect.
7032 =item Use of "goto" to jump into a construct is deprecated
7034 (D deprecated) Using C<goto> to jump from an outer scope into an inner
7035 scope is deprecated and should be avoided.
7037 This was deprecated in Perl 5.12.
7039 =item Use of inherited AUTOLOAD for non-method %s() is deprecated. This will be fatal in Perl 5.28
7041 (D deprecated) As an (ahem) accidental feature, C<AUTOLOAD>
7042 subroutines are looked up as methods (using the C<@ISA> hierarchy)
7043 even when the subroutines to be autoloaded were called as plain
7044 functions (e.g. C<Foo::bar()>), not as methods (e.g. C<< Foo->bar() >> or
7045 C<< $obj->bar() >>).
7047 This bug will be rectified in future by using method lookup only for
7048 methods' C<AUTOLOAD>s. However, there is a significant base of existing
7049 code that may be using the old behavior. So, as an interim step, Perl
7050 currently issues an optional warning when non-methods use inherited
7053 The simple rule is: Inheritance will not work when autoloading
7054 non-methods. The simple fix for old code is: In any module that used
7055 to depend on inheriting C<AUTOLOAD> for non-methods from a base class
7056 named C<BaseClass>, execute C<*AUTOLOAD = \&BaseClass::AUTOLOAD> during
7059 In code that currently says C<use AutoLoader; @ISA = qw(AutoLoader);>
7060 you should remove AutoLoader from @ISA and change C<use AutoLoader;> to
7061 C<use AutoLoader 'AUTOLOAD';>.
7063 This feature was deprecated in Perl 5.004, and will be fatal in Perl 5.28.
7065 =item Use of %s in printf format not supported
7067 (F) You attempted to use a feature of printf that is accessible from
7068 only C. This usually means there's a better way to do it in Perl.
7070 =item Use of -l on filehandle%s
7072 (W io) A filehandle represents an opened file, and when you opened the file
7073 it already went past any symlink you are presumably trying to look for.
7074 The operation returned C<undef>. Use a filename instead.
7076 =item Use of reference "%s" as array index
7078 (W misc) You tried to use a reference as an array index; this probably
7079 isn't what you mean, because references in numerical context tend
7080 to be huge numbers, and so usually indicates programmer error.
7082 If you really do mean it, explicitly numify your reference, like so:
7083 C<$array[0+$ref]>. This warning is not given for overloaded objects,
7084 however, because you can overload the numification and stringification
7085 operators and then you presumably know what you are doing.
7087 =item Use of state $_ is experimental
7089 (S experimental::lexical_topic) Lexical $_ is an experimental feature and
7090 its behavior may change or even be removed in any future release of perl.
7091 See the explanation under L<perlvar/$_>.
7093 =item Use of strings with code points over 0xFF as arguments to %s
7094 operator is deprecated. This will be a fatal error in Perl 5.28
7096 (D deprecated) You tried to use one of the string bitwise operators
7097 (C<&> or C<|> or C<^> or C<~>) on a string containing a code point over
7098 0xFF. The string bitwise operators treat their operands as strings of
7099 bytes, and values beyond 0xFF are nonsensical in this context.
7101 Such usage will be a fatal error in Perl 5.28.
7103 =item Use of tainted arguments in %s is deprecated
7105 (W taint, deprecated) You have supplied C<system()> or C<exec()> with multiple
7106 arguments and at least one of them is tainted. This used to be allowed
7107 but will become a fatal error in a future version of perl. Untaint your
7108 arguments. See L<perlsec>.
7110 =item Use of unassigned code point or non-standalone grapheme for a
7111 delimiter will be a fatal error starting in Perl 5.30
7114 A grapheme is what appears to a native-speaker of a language to be a
7115 character. In Unicode (and hence Perl) a grapheme may actually be
7116 several adjacent characters that together form a complete grapheme. For
7117 example, there can be a base character, like "R" and an accent, like a
7118 circumflex "^", that appear when displayed to be a single character with
7119 the circumflex hovering over the "R". Perl currently allows things like
7120 that circumflex to be delimiters of strings, patterns, I<etc>. When
7121 displayed, the circumflex would look like it belongs to the character
7122 just to the left of it. In order to move the language to be able to
7123 accept graphemes as delimiters, we have to deprecate the use of
7124 delimiters which aren't graphemes by themselves. Also, a delimiter must
7125 already be assigned (or known to be never going to be assigned) to try
7126 to future-proof code, for otherwise code that works today would fail to
7127 compile if the currently unassigned delimiter ends up being something
7128 that isn't a stand-alone grapheme. Because Unicode is never going to
7130 L<non-character code points|perlunicode/Noncharacter code points>, nor
7131 L<code points that are above the legal Unicode maximum|
7132 perlunicode/Beyond Unicode code points>, those can be delimiters, and
7133 their use won't raise this warning.
7135 =item Use of uninitialized value%s
7137 (W uninitialized) An undefined value was used as if it were already
7138 defined. It was interpreted as a "" or a 0, but maybe it was a mistake.
7139 To suppress this warning assign a defined value to your variables.
7141 To help you figure out what was undefined, perl will try to tell you
7142 the name of the variable (if any) that was undefined. In some cases
7143 it cannot do this, so it also tells you what operation you used the
7144 undefined value in. Note, however, that perl optimizes your program
7145 and the operation displayed in the warning may not necessarily appear
7146 literally in your program. For example, C<"that $foo"> is usually
7147 optimized into C<"that " . $foo>, and the warning will refer to the
7148 C<concatenation (.)> operator, even though there is no C<.> in
7151 =item "use re 'strict'" is experimental
7153 (S experimental::re_strict) The things that are different when a regular
7154 expression pattern is compiled under C<'strict'> are subject to change
7155 in future Perl releases in incompatible ways. This means that a pattern
7156 that compiles today may not in a future Perl release. This warning is
7157 to alert you to that risk.
7159 =item Use \x{...} for more than two hex characters in regex; marked by
7160 S<<-- HERE> in m/%s/
7162 (F) In a regular expression, you said something like
7166 Perl isn't sure if you meant this
7170 or if you meant this
7172 (?[ [ \x{BE} E F ] ])
7174 You need to add either braces or blanks to disambiguate.
7176 =item Using just the first character returned by \N{} in character class in
7177 regex; marked by S<<-- HERE> in m/%s/
7179 (W regexp) Named Unicode character escapes C<(\N{...})> may return
7180 a multi-character sequence. Even though a character class is
7181 supposed to match just one character of input, perl will match
7182 the whole thing correctly, except when the class is inverted
7183 (C<[^...]>), or the escape is the beginning or final end point of
7184 a range. For these, what should happen isn't clear at all. In
7185 these circumstances, Perl discards all but the first character
7186 of the returned sequence, which is not likely what you want.
7188 =item Using /u for '%s' instead of /%s in regex; marked by S<<-- HERE> in m/%s/
7190 (W regexp) You used a Unicode boundary (C<\b{...}> or C<\B{...}>) in a
7191 portion of a regular expression where the character set modifiers C</a>
7192 or C</aa> are in effect. These two modifiers indicate an ASCII
7193 interpretation, and this doesn't make sense for a Unicode defintion.
7194 The generated regular expression will compile so that the boundary uses
7195 all of Unicode. No other portion of the regular expression is affected.
7197 =item Using !~ with %s doesn't make sense
7199 (F) Using the C<!~> operator with C<s///r>, C<tr///r> or C<y///r> is
7200 currently reserved for future use, as the exact behavior has not
7201 been decided. (Simply returning the boolean opposite of the
7202 modified string is usually not particularly useful.)
7204 =item UTF-16 surrogate U+%X
7206 (S surrogate) You had a UTF-16 surrogate in a context where they are
7207 not considered acceptable. These code points, between U+D800 and
7208 U+DFFF (inclusive), are used by Unicode only for UTF-16. However, Perl
7209 internally allows all unsigned integer code points (up to the size limit
7210 available on your platform), including surrogates. But these can cause
7211 problems when being input or output, which is likely where this message
7212 came from. If you really really know what you are doing you can turn
7213 off this warning by C<no warnings 'surrogate';>.
7215 =item Value of %s can be "0"; test with defined()
7217 (W misc) In a conditional expression, you used <HANDLE>, <*> (glob),
7218 C<each()>, or C<readdir()> as a boolean value. Each of these constructs
7219 can return a value of "0"; that would make the conditional expression
7220 false, which is probably not what you intended. When using these
7221 constructs in conditional expressions, test their values with the
7222 C<defined> operator.
7224 =item Value of CLI symbol "%s" too long
7226 (W misc) A warning peculiar to VMS. Perl tried to read the value of an
7227 %ENV element from a CLI symbol table, and found a resultant string
7228 longer than 1024 characters. The return value has been truncated to
7231 =item Variable "%s" is not available
7233 (W closure) During compilation, an inner named subroutine or eval is
7234 attempting to capture an outer lexical that is not currently available.
7235 This can happen for one of two reasons. First, the outer lexical may be
7236 declared in an outer anonymous subroutine that has not yet been created.
7237 (Remember that named subs are created at compile time, while anonymous
7238 subs are created at run-time.) For example,
7240 sub { my $a; sub f { $a } }
7242 At the time that f is created, it can't capture the current value of $a,
7243 since the anonymous subroutine hasn't been created yet. Conversely,
7244 the following won't give a warning since the anonymous subroutine has by
7245 now been created and is live:
7247 sub { my $a; eval 'sub f { $a }' }->();
7249 The second situation is caused by an eval accessing a variable that has
7250 gone out of scope, for example,
7258 Here, when the '$a' in the eval is being compiled, f() is not currently
7259 being executed, so its $a is not available for capture.
7261 =item Variable "%s" is not imported%s
7263 (S misc) With "use strict" in effect, you referred to a global variable
7264 that you apparently thought was imported from another module, because
7265 something else of the same name (usually a subroutine) is exported by
7266 that module. It usually means you put the wrong funny character on the
7267 front of your variable.
7269 =item Variable length lookbehind not implemented in regex m/%s/
7271 (F) Lookbehind is allowed only for subexpressions whose length is fixed and
7272 known at compile time. For positive lookbehind, you can use the C<\K>
7273 regex construct as a way to get the equivalent functionality. See
7274 L<(?<=pattern) and \K in perlre|perlre/\K>.
7276 There are non-obvious Unicode rules under C</i> that can match variably,
7277 but which you might not think could. For example, the substring C<"ss">
7278 can match the single character LATIN SMALL LETTER SHARP S. There are
7279 other sequences of ASCII characters that can match single ligature
7280 characters, such as LATIN SMALL LIGATURE FFI matching C<qr/ffi/i>.
7281 Starting in Perl v5.16, if you only care about ASCII matches, adding the
7282 C</aa> modifier to the regex will exclude all these non-obvious matches,
7283 thus getting rid of this message. You can also say C<S<use re qw(/aa)>>
7284 to apply C</aa> to all regular expressions compiled within its scope.
7287 =item "%s" variable %s masks earlier declaration in same %s
7289 (W misc) A "my", "our" or "state" variable has been redeclared in the
7290 current scope or statement, effectively eliminating all access to the
7291 previous instance. This is almost always a typographical error. Note
7292 that the earlier variable will still exist until the end of the scope
7293 or until all closure references to it are destroyed.
7295 =item Variable syntax
7297 (A) You've accidentally run your script through B<csh> instead
7298 of Perl. Check the #! line, or manually feed your script into
7301 =item Variable "%s" will not stay shared
7303 (W closure) An inner (nested) I<named> subroutine is referencing a
7304 lexical variable defined in an outer named subroutine.
7306 When the inner subroutine is called, it will see the value of
7307 the outer subroutine's variable as it was before and during the *first*
7308 call to the outer subroutine; in this case, after the first call to the
7309 outer subroutine is complete, the inner and outer subroutines will no
7310 longer share a common value for the variable. In other words, the
7311 variable will no longer be shared.
7313 This problem can usually be solved by making the inner subroutine
7314 anonymous, using the C<sub {}> syntax. When inner anonymous subs that
7315 reference variables in outer subroutines are created, they
7316 are automatically rebound to the current values of such variables.
7318 =item vector argument not supported with alpha versions
7320 (S printf) The %vd (s)printf format does not support version objects
7323 =item Verb pattern '%s' has a mandatory argument in regex; marked by
7324 S<<-- HERE> in m/%s/
7326 (F) You used a verb pattern that requires an argument. Supply an
7327 argument or check that you are using the right verb.
7329 =item Verb pattern '%s' may not have an argument in regex; marked by
7330 S<<-- HERE> in m/%s/
7332 (F) You used a verb pattern that is not allowed an argument. Remove the
7333 argument or check that you are using the right verb.
7335 =item Version control conflict marker
7337 (F) The parser found a line starting with C<E<lt><<<<<<>,
7338 C<E<gt>E<gt>E<gt>E<gt>E<gt>E<gt>E<gt>>, or C<=======>. These may be left by a
7339 version control system to mark conflicts after a failed merge operation.
7341 =item Version number must be a constant number
7343 (P) The attempt to translate a C<use Module n.n LIST> statement into
7344 its equivalent C<BEGIN> block found an internal inconsistency with
7347 =item Version string '%s' contains invalid data; ignoring: '%s'
7349 (W misc) The version string contains invalid characters at the end, which
7352 =item Warning: something's wrong
7354 (W) You passed warn() an empty string (the equivalent of C<warn "">) or
7355 you called it with no args and C<$@> was empty.
7357 =item Warning: unable to close filehandle %s properly
7359 (S) The implicit close() done by an open() got an error indication on
7360 the close(). This usually indicates your file system ran out of disk
7363 =item Warning: unable to close filehandle properly: %s
7365 =item Warning: unable to close filehandle %s properly: %s
7367 (S io) There were errors during the implicit close() done on a filehandle
7368 when its reference count reached zero while it was still open, e.g.:
7371 open my $fh, '>', $file or die "open: '$file': $!\n";
7372 print $fh $data or die "print: $!";
7373 } # implicit close here
7375 Because various errors may only be detected by close() (e.g. buffering could
7376 allow the C<print> in this example to return true even when the disk is full),
7377 it is dangerous to ignore its result. So when it happens implicitly, perl
7378 will signal errors by warning.
7380 B<Prior to version 5.22.0, perl ignored such errors>, so the common idiom shown
7381 above was liable to cause B<silent data loss>.
7383 =item Warning: Use of "%s" without parentheses is ambiguous
7385 (S ambiguous) You wrote a unary operator followed by something that
7386 looks like a binary operator that could also have been interpreted as a
7387 term or unary operator. For instance, if you know that the rand
7388 function has a default argument of 1.0, and you write
7392 you may THINK you wrote the same thing as
7396 but in actual fact, you got
7400 So put in parentheses to say what you really mean.
7402 =item when is experimental
7404 (S experimental::smartmatch) C<when> depends on smartmatch, which is
7405 experimental. Additionally, it has several special cases that may
7406 not be immediately obvious, and their behavior may change or
7407 even be removed in any future release of perl. See the explanation
7408 under L<perlsyn/Experimental Details on given and when>.
7410 =item Wide character in %s
7412 (S utf8) Perl met a wide character (>255) when it wasn't expecting
7413 one. This warning is by default on for I/O (like print). The easiest
7414 way to quiet this warning is simply to add the C<:utf8> layer to the
7415 output, e.g. C<binmode STDOUT, ':utf8'>. Another way to turn off the
7416 warning is to add C<no warnings 'utf8';> but that is often closer to
7417 cheating. In general, you are supposed to explicitly mark the
7418 filehandle with an encoding, see L<open> and L<perlfunc/binmode>.
7420 =item Wide character (U+%X) in %s
7422 (W locale) While in a single-byte locale (I<i.e.>, a non-UTF-8
7423 one), a multi-byte character was encountered. Perl considers this
7424 character to be the specified Unicode code point. Combining non-UTF-8
7425 locales and Unicode is dangerous. Almost certainly some characters
7426 will have two different representations. For example, in the ISO 8859-7
7427 (Greek) locale, the code point 0xC3 represents a Capital Gamma. But so
7428 also does 0x393. This will make string comparisons unreliable.
7430 You likely need to figure out how this multi-byte character got mixed up
7431 with your single-byte locale (or perhaps you thought you had a UTF-8
7432 locale, but Perl disagrees).
7434 =item Within []-length '%c' not allowed
7436 (F) The count in the (un)pack template may be replaced by C<[TEMPLATE]>
7437 only if C<TEMPLATE> always matches the same amount of packed bytes that
7438 can be determined from the template alone. This is not possible if
7439 it contains any of the codes @, /, U, u, w or a *-length. Redesign
7442 =item %s() with negative argument
7444 (S misc) Certain operations make no sense with negative arguments.
7445 Warning is given and the operation is not done.
7447 =item write() on closed filehandle %s
7449 (W closed) The filehandle you're writing to got itself closed sometime
7450 before now. Check your control flow.
7452 =item %s "\x%X" does not map to Unicode
7454 (S utf8) When reading in different encodings, Perl tries to
7455 map everything into Unicode characters. The bytes you read
7456 in are not legal in this encoding. For example
7458 utf8 "\xE4" does not map to Unicode
7460 if you try to read in the a-diaereses Latin-1 as UTF-8.
7462 =item 'X' outside of string
7464 (F) You had a (un)pack template that specified a relative position before
7465 the beginning of the string being (un)packed. See L<perlfunc/pack>.
7467 =item 'x' outside of string in unpack
7469 (F) You had a pack template that specified a relative position after
7470 the end of the string being unpacked. See L<perlfunc/pack>.
7472 =item YOU HAVEN'T DISABLED SET-ID SCRIPTS IN THE KERNEL YET!
7474 (F) And you probably never will, because you probably don't have the
7475 sources to your kernel, and your vendor probably doesn't give a rip
7476 about what you want. Your best bet is to put a setuid C wrapper around
7479 =item You need to quote "%s"
7481 (W syntax) You assigned a bareword as a signal handler name.
7482 Unfortunately, you already have a subroutine of that name declared,
7483 which means that Perl 5 will try to call the subroutine when the
7484 assignment is executed, which is probably not what you want. (If it IS
7485 what you want, put an & in front.)
7487 =item Your random numbers are not that random
7489 (F) When trying to initialize the random seed for hashes, Perl could
7490 not get any randomness out of your system. This usually indicates
7491 Something Very Wrong.
7493 =item Zero length \N{} in regex; marked by S<<-- HERE> in m/%s/
7495 (F) Named Unicode character escapes (C<\N{...}>) may return a zero-length
7496 sequence. Such an escape was used in an extended character class, i.e.
7497 C<(?[...])>, or under C<use re 'strict'>, which is not permitted. Check
7498 that the correct escape has been used, and the correct charnames handler
7499 is in scope. The S<<-- HERE> shows whereabouts in the regular
7500 expression the problem was discovered.
7506 L<warnings>, L<diagnostics>.