3 perldiag - various Perl diagnostics
7 These messages are classified as follows (listed in increasing order of
10 (W) A warning (optional).
11 (D) A deprecation (enabled by default).
12 (S) A severe warning (enabled by default).
13 (F) A fatal error (trappable).
14 (P) An internal error you should never see (trappable).
15 (X) A very fatal error (nontrappable).
16 (A) An alien error message (not generated by Perl).
18 The majority of messages from the first three classifications above
19 (W, D & S) can be controlled using the C<warnings> pragma.
21 If a message can be controlled by the C<warnings> pragma, its warning
22 category is included with the classification letter in the description
23 below. E.g. C<(W closed)> means a warning in the C<closed> category.
25 Optional warnings are enabled by using the C<warnings> pragma or the B<-w>
26 and B<-W> switches. Warnings may be captured by setting C<$SIG{__WARN__}>
27 to a reference to a routine that will be called on each warning instead
28 of printing it. See L<perlvar>.
30 Severe warnings are always enabled, unless they are explicitly disabled
31 with the C<warnings> pragma or the B<-X> switch.
33 Trappable errors may be trapped using the eval operator. See
34 L<perlfunc/eval>. In almost all cases, warnings may be selectively
35 disabled or promoted to fatal errors using the C<warnings> pragma.
38 The messages are in alphabetical order, without regard to upper or
39 lower-case. Some of these messages are generic. Spots that vary are
40 denoted with a %s or other printf-style escape. These escapes are
41 ignored by the alphabetical order, as are all characters other than
42 letters. To look up your message, just ignore anything that is not a
47 =item accept() on closed socket %s
49 (W closed) You tried to do an accept on a closed socket. Did you forget
50 to check the return value of your socket() call? See
53 =item Aliasing via reference is experimental
55 (S experimental::refaliasing) This warning is emitted if you use
56 a reference constructor on the left-hand side of an assignment to
57 alias one variable to another. Simply suppress the warning if you
58 want to use the feature, but know that in doing so you are taking
59 the risk of using an experimental feature which may change or be
60 removed in a future Perl version:
62 no warnings "experimental::refaliasing";
63 use feature "refaliasing";
66 =item Allocation too large: %x
68 (X) You can't allocate more than 64K on an MS-DOS machine.
70 =item '%c' allowed only after types %s in %s
72 (F) The modifiers '!', '<' and '>' are allowed in pack() or unpack() only
73 after certain types. See L<perlfunc/pack>.
75 =item alpha->numify() is lossy
77 (W numeric) An alpha version can not be numified without losing
80 =item Ambiguous call resolved as CORE::%s(), qualify as such or use &
82 (W ambiguous) A subroutine you have declared has the same name as a Perl
83 keyword, and you have used the name without qualification for calling
84 one or the other. Perl decided to call the builtin because the
85 subroutine is not imported.
87 To force interpretation as a subroutine call, either put an ampersand
88 before the subroutine name, or qualify the name with its package.
89 Alternatively, you can import the subroutine (or pretend that it's
90 imported with the C<use subs> pragma).
92 To silently interpret it as the Perl operator, use the C<CORE::> prefix
93 on the operator (e.g. C<CORE::log($x)>) or declare the subroutine
94 to be an object method (see L<perlsub/"Subroutine Attributes"> or
97 =item Ambiguous range in transliteration operator
99 (F) You wrote something like C<tr/a-z-0//> which doesn't mean anything at
100 all. To include a C<-> character in a transliteration, put it either
101 first or last. (In the past, C<tr/a-z-0//> was synonymous with
102 C<tr/a-y//>, which was probably not what you would have expected.)
104 =item Ambiguous use of %s resolved as %s
106 (S ambiguous) You said something that may not be interpreted the way
107 you thought. Normally it's pretty easy to disambiguate it by supplying
108 a missing quote, operator, parenthesis pair or declaration.
110 =item Ambiguous use of -%s resolved as -&%s()
112 (S ambiguous) You wrote something like C<-foo>, which might be the
113 string C<"-foo">, or a call to the function C<foo>, negated. If you meant
114 the string, just write C<"-foo">. If you meant the function call,
117 =item Ambiguous use of %c resolved as operator %c
119 (S ambiguous) C<%>, C<&>, and C<*> are both infix operators (modulus,
120 bitwise and, and multiplication) I<and> initial special characters
121 (denoting hashes, subroutines and typeglobs), and you said something
122 like C<*foo * foo> that might be interpreted as either of them. We
123 assumed you meant the infix operator, but please try to make it more
124 clear -- in the example given, you might write C<*foo * foo()> if you
125 really meant to multiply a glob by the result of calling a function.
127 =item Ambiguous use of %c{%s} resolved to %c%s
129 (W ambiguous) You wrote something like C<@{foo}>, which might be
130 asking for the variable C<@foo>, or it might be calling a function
131 named foo, and dereferencing it as an array reference. If you wanted
132 the variable, you can just write C<@foo>. If you wanted to call the
133 function, write C<@{foo()}> ... or you could just not have a variable
134 and a function with the same name, and save yourself a lot of trouble.
136 =item Ambiguous use of %c{%s[...]} resolved to %c%s[...]
138 =item Ambiguous use of %c{%s{...}} resolved to %c%s{...}
140 (W ambiguous) You wrote something like C<${foo[2]}> (where foo represents
141 the name of a Perl keyword), which might be looking for element number
142 2 of the array named C<@foo>, in which case please write C<$foo[2]>, or you
143 might have meant to pass an anonymous arrayref to the function named
144 foo, and then do a scalar deref on the value it returns. If you meant
145 that, write C<${foo([2])}>.
147 In regular expressions, the C<${foo[2]}> syntax is sometimes necessary
148 to disambiguate between array subscripts and character classes.
149 C</$length[2345]/>, for instance, will be interpreted as C<$length> followed
150 by the character class C<[2345]>. If an array subscript is what you
151 want, you can avoid the warning by changing C</${length[2345]}/> to the
152 unsightly C</${\$length[2345]}/>, by renaming your array to something
153 that does not coincide with a built-in keyword, or by simply turning
154 off warnings with C<no warnings 'ambiguous';>.
156 =item '|' and '<' may not both be specified on command line
158 (F) An error peculiar to VMS. Perl does its own command line
159 redirection, and found that STDIN was a pipe, and that you also tried to
160 redirect STDIN using '<'. Only one STDIN stream to a customer, please.
162 =item '|' and '>' may not both be specified on command line
164 (F) An error peculiar to VMS. Perl does its own command line
165 redirection, and thinks you tried to redirect stdout both to a file and
166 into a pipe to another command. You need to choose one or the other,
167 though nothing's stopping you from piping into a program or Perl script
168 which 'splits' output into two streams, such as
170 open(OUT,">$ARGV[0]") or die "Can't write to $ARGV[0]: $!";
177 =item Applying %s to %s will act on scalar(%s)
179 (W misc) The pattern match (C<//>), substitution (C<s///>), and
180 transliteration (C<tr///>) operators work on scalar values. If you apply
181 one of them to an array or a hash, it will convert the array or hash to
182 a scalar value (the length of an array, or the population info of a
183 hash) and then work on that scalar value. This is probably not what
184 you meant to do. See L<perlfunc/grep> and L<perlfunc/map> for
187 =item Arg too short for msgsnd
189 (F) msgsnd() requires a string at least as long as sizeof(long).
191 =item Argument "%s" isn't numeric%s
193 (W numeric) The indicated string was fed as an argument to an operator
194 that expected a numeric value instead. If you're fortunate the message
195 will identify which operator was so unfortunate.
197 Note that for the C<Inf> and C<NaN> (infinity and not-a-number) the
198 definition of "numeric" is somewhat unusual: the strings themselves
199 (like "Inf") are considered numeric, and anything following them is
200 considered non-numeric.
202 =item Argument list not closed for PerlIO layer "%s"
204 (W layer) When pushing a layer with arguments onto the Perl I/O
205 system you forgot the ) that closes the argument list. (Layers
206 take care of transforming data between external and internal
207 representations.) Perl stopped parsing the layer list at this
208 point and did not attempt to push this layer. If your program
209 didn't explicitly request the failing operation, it may be the
210 result of the value of the environment variable PERLIO.
212 =item Argument "%s" treated as 0 in increment (++)
214 (W numeric) The indicated string was fed as an argument to the C<++>
215 operator which expects either a number or a string matching
216 C</^[a-zA-Z]*[0-9]*\z/>. See L<perlop/Auto-increment and
217 Auto-decrement> for details.
219 =item Array passed to stat will be coerced to a scalar%s
221 (W syntax) You called stat() on an array, but the array will be
222 coerced to a scalar - the number of elements in the array.
224 =item A signature parameter must start with '$', '@' or '%'
226 (F) Each subroutine signature parameter declaration must start with a valid
229 sub foo ($a, $, $b = 1, @c) {}
231 =item A slurpy parameter may not have a default value
233 (F) Only scalar subroutine signature parameters may have a default value;
236 sub foo ($a = 1) {} # legal
237 sub foo (@a = (1)) {} # invalid
238 sub foo (%a = (a => b)) {} # invalid
240 =item assertion botched: %s
242 (X) The malloc package that comes with Perl had an internal failure.
244 =item Assertion %s failed: file "%s", line %d
246 (X) A general assertion failed. The file in question must be examined.
248 =item Assigned value is not a reference
250 (F) You tried to assign something that was not a reference to an lvalue
251 reference (e.g., C<\$x = $y>). If you meant to make $x an alias to $y, use
254 =item Assigned value is not %s reference
256 (F) You tried to assign a reference to a reference constructor, but the
257 two references were not of the same type. You cannot alias a scalar to
258 an array, or an array to a hash; the two types must match.
263 \$x = $y; # error; did you mean \$y?
265 =item Assigning non-zero to $[ is no longer possible
267 (F) When the "array_base" feature is disabled
268 (e.g., and under C<use v5.16;>, and as of Perl 5.30)
269 the special variable C<$[>, which is deprecated, is now a fixed zero value.
271 =item Assignment to both a list and a scalar
273 (F) If you assign to a conditional operator, the 2nd and 3rd arguments
274 must either both be scalars or both be lists. Otherwise Perl won't
275 know which context to supply to the right side.
277 =item Assuming NOT a POSIX class since %s in regex; marked by S<<-- HERE> in m/%s/
279 (W regexp) You had something like these:
284 They look like they might have been meant to be the POSIX classes
285 C<[:alnum:]> or C<[:digit:]>. If so, they should be written:
290 Since these aren't legal POSIX class specifications, but are legal
291 bracketed character classes, Perl treats them as the latter. In the
292 first example, it matches the characters C<":">, C<"[">, C<"a">, C<"l">,
293 C<"m">, C<"n">, and C<"u">.
295 If these weren't meant to be POSIX classes, this warning message is
296 spurious, and can be suppressed by reordering things, such as
304 =item <> at require-statement should be quotes
306 (F) You wrote C<< require <file> >> when you should have written
309 =item Attempt to access disallowed key '%s' in a restricted hash
311 (F) The failing code has attempted to get or set a key which is not in
312 the current set of allowed keys of a restricted hash.
314 =item Attempt to bless into a freed package
316 (F) You wrote C<bless $foo> with one argument after somehow causing
317 the current package to be freed. Perl cannot figure out what to
318 do, so it throws up its hands in despair.
320 =item Attempt to bless into a reference
322 (F) The CLASSNAME argument to the bless() operator is expected to be
323 the name of the package to bless the resulting object into. You've
324 supplied instead a reference to something: perhaps you wrote
330 bless $self, ref($proto) || $proto;
332 If you actually want to bless into the stringified version
333 of the reference supplied, you need to stringify it yourself, for
336 bless $self, "$proto";
338 =item Attempt to clear deleted array
340 (S debugging) An array was assigned to when it was being freed.
341 Freed values are not supposed to be visible to Perl code. This
342 can also happen if XS code calls C<av_clear> from a custom magic
343 callback on the array.
345 =item Attempt to delete disallowed key '%s' from a restricted hash
347 (F) The failing code attempted to delete from a restricted hash a key
348 which is not in its key set.
350 =item Attempt to delete readonly key '%s' from a restricted hash
352 (F) The failing code attempted to delete a key whose value has been
353 declared readonly from a restricted hash.
355 =item Attempt to free non-arena SV: 0x%x
357 (S internal) All SV objects are supposed to be allocated from arenas
358 that will be garbage collected on exit. An SV was discovered to be
359 outside any of those arenas.
361 =item Attempt to free nonexistent shared string '%s'%s
363 (S internal) Perl maintains a reference-counted internal table of
364 strings to optimize the storage and access of hash keys and other
365 strings. This indicates someone tried to decrement the reference count
366 of a string that can no longer be found in the table.
368 =item Attempt to free temp prematurely: SV 0x%x
370 (S debugging) Mortalized values are supposed to be freed by the
371 free_tmps() routine. This indicates that something else is freeing the
372 SV before the free_tmps() routine gets a chance, which means that the
373 free_tmps() routine will be freeing an unreferenced scalar when it does
376 =item Attempt to free unreferenced glob pointers
378 (S internal) The reference counts got screwed up on symbol aliases.
380 =item Attempt to free unreferenced scalar: SV 0x%x
382 (S internal) Perl went to decrement the reference count of a scalar to
383 see if it would go to 0, and discovered that it had already gone to 0
384 earlier, and should have been freed, and in fact, probably was freed.
385 This could indicate that SvREFCNT_dec() was called too many times, or
386 that SvREFCNT_inc() was called too few times, or that the SV was
387 mortalized when it shouldn't have been, or that memory has been
390 =item Attempt to pack pointer to temporary value
392 (W pack) You tried to pass a temporary value (like the result of a
393 function, or a computed expression) to the "p" pack() template. This
394 means the result contains a pointer to a location that could become
395 invalid anytime, even before the end of the current statement. Use
396 literals or global values as arguments to the "p" pack() template to
399 =item Attempt to reload %s aborted.
401 (F) You tried to load a file with C<use> or C<require> that failed to
402 compile once already. Perl will not try to compile this file again
403 unless you delete its entry from %INC. See L<perlfunc/require> and
406 =item Attempt to set length of freed array
408 (W misc) You tried to set the length of an array which has
409 been freed. You can do this by storing a reference to the
410 scalar representing the last index of an array and later
411 assigning through that reference. For example
413 $r = do {my @a; \$#a};
416 =item Attempt to use reference as lvalue in substr
418 (W substr) You supplied a reference as the first argument to substr()
419 used as an lvalue, which is pretty strange. Perhaps you forgot to
420 dereference it first. See L<perlfunc/substr>.
422 =item Attribute prototype(%s) discards earlier prototype attribute in same sub
424 (W misc) A sub was declared as sub foo : prototype(A) : prototype(B) {}, for
425 example. Since each sub can only have one prototype, the earlier
426 declaration(s) are discarded while the last one is applied.
428 =item av_reify called on tied array
430 (S debugging) This indicates that something went wrong and Perl got I<very>
431 confused about C<@_> or C<@DB::args> being tied.
433 =item Bad arg length for %s, is %u, should be %d
435 (F) You passed a buffer of the wrong size to one of msgctl(), semctl()
436 or shmctl(). In C parlance, the correct sizes are, respectively,
437 S<sizeof(struct msqid_ds *)>, S<sizeof(struct semid_ds *)>, and
438 S<sizeof(struct shmid_ds *)>.
440 =item Bad evalled substitution pattern
442 (F) You've used the C</e> switch to evaluate the replacement for a
443 substitution, but perl found a syntax error in the code to evaluate,
444 most likely an unexpected right brace '}'.
446 =item Bad filehandle: %s
448 (F) A symbol was passed to something wanting a filehandle, but the
449 symbol has no filehandle associated with it. Perhaps you didn't do an
450 open(), or did it in another package.
452 =item Bad free() ignored
454 (S malloc) An internal routine called free() on something that had never
455 been malloc()ed in the first place. Mandatory, but can be disabled by
456 setting environment variable C<PERL_BADFREE> to 0.
458 This message can be seen quite often with DB_File on systems with "hard"
459 dynamic linking, like C<AIX> and C<OS/2>. It is a bug of C<Berkeley DB>
460 which is left unnoticed if C<DB> uses I<forgiving> system malloc().
464 (P) One of the internal hash routines was passed a null HV pointer.
466 =item Badly placed ()'s
468 (A) You've accidentally run your script through B<csh> instead
469 of Perl. Check the #! line, or manually feed your script into
472 =item Bad name after %s
474 (F) You started to name a symbol by using a package prefix, and then
475 didn't finish the symbol. In particular, you can't interpolate outside
484 $sym = "mypack::$var";
486 =item Bad plugin affecting keyword '%s'
488 (F) An extension using the keyword plugin mechanism violated the
491 =item Bad realloc() ignored
493 (S malloc) An internal routine called realloc() on something that
494 had never been malloc()ed in the first place. Mandatory, but can
495 be disabled by setting the environment variable C<PERL_BADFREE> to 1.
497 =item Bad symbol for array
499 (P) An internal request asked to add an array entry to something that
500 wasn't a symbol table entry.
502 =item Bad symbol for dirhandle
504 (P) An internal request asked to add a dirhandle entry to something
505 that wasn't a symbol table entry.
507 =item Bad symbol for filehandle
509 (P) An internal request asked to add a filehandle entry to something
510 that wasn't a symbol table entry.
512 =item Bad symbol for hash
514 (P) An internal request asked to add a hash entry to something that
515 wasn't a symbol table entry.
517 =item Bad symbol for scalar
519 (P) An internal request asked to add a scalar entry to something that
520 wasn't a symbol table entry.
522 =item Bareword found in conditional
524 (W bareword) The compiler found a bareword where it expected a
525 conditional, which often indicates that an || or && was parsed as part
526 of the last argument of the previous construct, for example:
530 It may also indicate a misspelled constant that has been interpreted as
533 use constant TYPO => 1;
534 if (TYOP) { print "foo" }
536 The C<strict> pragma is useful in avoiding such errors.
538 =item Bareword in require contains "%s"
540 =item Bareword in require maps to disallowed filename "%s"
542 =item Bareword in require maps to empty filename
544 (F) The bareword form of require has been invoked with a filename which could
545 not have been generated by a valid bareword permitted by the parser. You
546 shouldn't be able to get this error from Perl code, but XS code may throw it
547 if it passes an invalid module name to C<Perl_load_module>.
549 =item Bareword in require must not start with a double-colon: "%s"
551 (F) In C<require Bare::Word>, the bareword is not allowed to start with a
552 double-colon. Write C<require ::Foo::Bar> as C<require Foo::Bar> instead.
554 =item Bareword "%s" not allowed while "strict subs" in use
556 (F) With "strict subs" in use, a bareword is only allowed as a
557 subroutine identifier, in curly brackets or to the left of the "=>"
558 symbol. Perhaps you need to predeclare a subroutine?
560 =item Bareword "%s" refers to nonexistent package
562 (W bareword) You used a qualified bareword of the form C<Foo::>, but the
563 compiler saw no other uses of that namespace before that point. Perhaps
564 you need to predeclare a package?
566 =item BEGIN failed--compilation aborted
568 (F) An untrapped exception was raised while executing a BEGIN
569 subroutine. Compilation stops immediately and the interpreter is
572 =item BEGIN not safe after errors--compilation aborted
574 (F) Perl found a C<BEGIN {}> subroutine (or a C<use> directive, which
575 implies a C<BEGIN {}>) after one or more compilation errors had already
576 occurred. Since the intended environment for the C<BEGIN {}> could not
577 be guaranteed (due to the errors), and since subsequent code likely
578 depends on its correct operation, Perl just gave up.
580 =item \%d better written as $%d
582 (W syntax) Outside of patterns, backreferences live on as variables.
583 The use of backslashes is grandfathered on the right-hand side of a
584 substitution, but stylistically it's better to use the variable form
585 because other Perl programmers will expect it, and it works better if
586 there are more than 9 backreferences.
588 =item Binary number > 0b11111111111111111111111111111111 non-portable
590 (W portable) The binary number you specified is larger than 2**32-1
591 (4294967295) and therefore non-portable between systems. See
592 L<perlport> for more on portability concerns.
594 =item bind() on closed socket %s
596 (W closed) You tried to do a bind on a closed socket. Did you forget to
597 check the return value of your socket() call? See L<perlfunc/bind>.
599 =item binmode() on closed filehandle %s
601 (W unopened) You tried binmode() on a filehandle that was never opened.
602 Check your control flow and number of arguments.
604 =item Bit vector size > 32 non-portable
606 (W portable) Using bit vector sizes larger than 32 is non-portable.
608 =item Bizarre copy of %s
610 (P) Perl detected an attempt to copy an internal value that is not
613 =item Bizarre SvTYPE [%d]
615 (P) When starting a new thread or returning values from a thread, Perl
616 encountered an invalid data type.
618 =item Both or neither range ends should be Unicode in regex; marked by
621 (W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
623 In a bracketed character class in a regular expression pattern, you
624 had a range which has exactly one end of it specified using C<\N{}>, and
625 the other end is specified using a non-portable mechanism. Perl treats
626 the range as a Unicode range, that is, all the characters in it are
627 considered to be the Unicode characters, and which may be different code
628 points on some platforms Perl runs on. For example, C<[\N{U+06}-\x08]>
629 is treated as if you had instead said C<[\N{U+06}-\N{U+08}]>, that is it
630 matches the characters whose code points in Unicode are 6, 7, and 8.
631 But that C<\x08> might indicate that you meant something different, so
632 the warning gets raised.
634 =item Buffer overflow in prime_env_iter: %s
636 (W internal) A warning peculiar to VMS. While Perl was preparing to
637 iterate over %ENV, it encountered a logical name or symbol definition
638 which was too long, so it was truncated to the string shown.
640 =item Callback called exit
642 (F) A subroutine invoked from an external package via call_sv()
643 exited by calling exit.
645 =item %s() called too early to check prototype
647 (W prototype) You've called a function that has a prototype before the
648 parser saw a definition or declaration for it, and Perl could not check
649 that the call conforms to the prototype. You need to either add an
650 early prototype declaration for the subroutine in question, or move the
651 subroutine definition ahead of the call to get proper prototype
652 checking. Alternatively, if you are certain that you're calling the
653 function correctly, you may put an ampersand before the name to avoid
654 the warning. See L<perlsub>.
658 (F) You passed an invalid number (like an infinity or not-a-number) to C<chr>.
660 =item Cannot complete in-place edit of %s: %s
662 (F) Your perl script appears to have changed directory while
663 performing an in-place edit of a file specified by a relative path,
664 and your system doesn't include the directory relative POSIX functions
665 needed to handle that.
667 =item Cannot compress %f in pack
669 (F) You tried compressing an infinity or not-a-number as an unsigned
670 integer with BER, which makes no sense.
672 =item Cannot compress integer in pack
674 (F) An argument to pack("w",...) was too large to compress.
675 The BER compressed integer format can only be used with positive
676 integers, and you attempted to compress a very large number (> 1e308).
677 See L<perlfunc/pack>.
679 =item Cannot compress negative numbers in pack
681 (F) An argument to pack("w",...) was negative. The BER compressed integer
682 format can only be used with positive integers. See L<perlfunc/pack>.
684 =item Cannot convert a reference to %s to typeglob
686 (F) You manipulated Perl's symbol table directly, stored a reference
687 in it, then tried to access that symbol via conventional Perl syntax.
688 The access triggers Perl to autovivify that typeglob, but it there is
689 no legal conversion from that type of reference to a typeglob.
691 =item Cannot copy to %s
693 (P) Perl detected an attempt to copy a value to an internal type that cannot
694 be directly assigned to.
696 =item Cannot find encoding "%s"
698 (S io) You tried to apply an encoding that did not exist to a filehandle,
699 either with open() or binmode().
701 =item Cannot open %s as a dirhandle: it is already open as a filehandle
703 (F) You tried to use opendir() to associate a dirhandle to a symbol (glob
704 or scalar) that already holds a filehandle. Since this idiom might render
705 your code confusing, it was deprecated in Perl 5.10. As of Perl 5.28, it
708 =item Cannot open %s as a filehandle: it is already open as a dirhandle
710 (F) You tried to use open() to associate a filehandle to a symbol (glob
711 or scalar) that already holds a dirhandle. Since this idiom might render
712 your code confusing, it was deprecated in Perl 5.10. As of Perl 5.28, it
715 =item Cannot pack %f with '%c'
717 (F) You tried converting an infinity or not-a-number to an integer,
718 which makes no sense.
720 =item Cannot printf %f with '%c'
722 (F) You tried printing an infinity or not-a-number as a character (%c),
723 which makes no sense. Maybe you meant '%s', or just stringifying it?
725 =item Cannot set tied @DB::args
727 (F) C<caller> tried to set C<@DB::args>, but found it tied. Tying C<@DB::args>
728 is not supported. (Before this error was added, it used to crash.)
730 =item Cannot tie unreifiable array
732 (P) You somehow managed to call C<tie> on an array that does not
733 keep a reference count on its arguments and cannot be made to
734 do so. Such arrays are not even supposed to be accessible to
735 Perl code, but are only used internally.
737 =item Cannot yet reorder sv_vcatpvfn() arguments from va_list
739 (F) Some XS code tried to use C<sv_vcatpvfn()> or a related function with a
740 format string that specifies explicit indexes for some of the elements, and
741 using a C-style variable-argument list (a C<va_list>). This is not currently
742 supported. XS authors wanting to do this must instead construct a C array
743 of C<SV*> scalars containing the arguments.
745 =item Can only compress unsigned integers in pack
747 (F) An argument to pack("w",...) was not an integer. The BER compressed
748 integer format can only be used with positive integers, and you attempted
749 to compress something else. See L<perlfunc/pack>.
751 =item Can't bless non-reference value
753 (F) Only hard references may be blessed. This is how Perl "enforces"
754 encapsulation of objects. See L<perlobj>.
756 =item Can't "break" in a loop topicalizer
758 (F) You called C<break>, but you're in a C<foreach> block rather than
759 a C<given> block. You probably meant to use C<next> or C<last>.
761 =item Can't "break" outside a given block
763 (F) You called C<break>, but you're not inside a C<given> block.
765 =item Can't call method "%s" on an undefined value
767 (F) You used the syntax of a method call, but the slot filled by the
768 object reference or package name contains an undefined value. Something
769 like this will reproduce the error:
772 process $BADREF 1,2,3;
773 $BADREF->process(1,2,3);
775 =item Can't call method "%s" on unblessed reference
777 (F) A method call must know in what package it's supposed to run. It
778 ordinarily finds this out from the object reference you supply, but you
779 didn't supply an object reference in this case. A reference isn't an
780 object reference until it has been blessed. See L<perlobj>.
782 =item Can't call method "%s" without a package or object reference
784 (F) You used the syntax of a method call, but the slot filled by the
785 object reference or package name contains an expression that returns a
786 defined value which is neither an object reference nor a package name.
787 Something like this will reproduce the error:
790 process $BADREF 1,2,3;
791 $BADREF->process(1,2,3);
793 =item Can't call mro_isa_changed_in() on anonymous symbol table
795 (P) Perl got confused as to whether a hash was a plain hash or a
796 symbol table hash when trying to update @ISA caches.
798 =item Can't call mro_method_changed_in() on anonymous symbol table
800 (F) An XS module tried to call C<mro_method_changed_in> on a hash that was
801 not attached to the symbol table.
803 =item Can't chdir to %s
805 (F) You called C<perl -x/foo/bar>, but F</foo/bar> is not a directory
806 that you can chdir to, possibly because it doesn't exist.
808 =item Can't check filesystem of script "%s" for nosuid
810 (P) For some reason you can't check the filesystem of the script for
813 =item Can't coerce %s to %s in %s
815 (F) Certain types of SVs, in particular real symbol table entries
816 (typeglobs), can't be forced to stop being what they are. So you can't
826 but then $foo no longer contains a glob.
828 =item Can't "continue" outside a when block
830 (F) You called C<continue>, but you're not inside a C<when>
833 =item Can't create pipe mailbox
835 (P) An error peculiar to VMS. The process is suffering from exhausted
836 quotas or other plumbing problems.
838 =item Can't declare %s in "%s"
840 (F) Only scalar, array, and hash variables may be declared as "my", "our" or
841 "state" variables. They must have ordinary identifiers as names.
843 =item Can't "default" outside a topicalizer
845 (F) You have used a C<default> block that is neither inside a
846 C<foreach> loop nor a C<given> block. (Note that this error is
847 issued on exit from the C<default> block, so you won't get the
848 error if you use an explicit C<continue>.)
850 =item Can't determine class of operator %s, assuming BASEOP
852 (S) This warning indicates something wrong in the internals of perl.
853 Perl was trying to find the class (e.g. LISTOP) of a particular OP,
854 and was unable to do so. This is likely to be due to a bug in the perl
855 internals, or due to a bug in XS code which manipulates perl optrees.
857 =item Can't do inplace edit: %s is not a regular file
859 (S inplace) You tried to use the B<-i> switch on a special file, such as
860 a file in /dev, a FIFO or an uneditable directory. The file was ignored.
862 =item Can't do inplace edit on %s: %s
864 (S inplace) The creation of the new file failed for the indicated
867 =item Can't do inplace edit: %s would not be unique
869 (S inplace) Your filesystem does not support filenames longer than 14
870 characters and Perl was unable to create a unique filename during
871 inplace editing with the B<-i> switch. The file was ignored.
873 =item Can't do %s("%s") on non-UTF-8 locale; resolved to "%s".
875 (W locale) You are 1) running under "C<use locale>"; 2) the current
876 locale is not a UTF-8 one; 3) you tried to do the designated case-change
877 operation on the specified Unicode character; and 4) the result of this
878 operation would mix Unicode and locale rules, which likely conflict.
879 Mixing of different rule types is forbidden, so the operation was not
880 done; instead the result is the indicated value, which is the best
881 available that uses entirely Unicode rules. That turns out to almost
882 always be the original character, unchanged.
884 It is generally a bad idea to mix non-UTF-8 locales and Unicode, and
885 this issue is one of the reasons why. This warning is raised when
886 Unicode rules would normally cause the result of this operation to
887 contain a character that is in the range specified by the locale,
888 0..255, and hence is subject to the locale's rules, not Unicode's.
890 If you are using locale purely for its characteristics related to things
891 like its numeric and time formatting (and not C<LC_CTYPE>), consider
892 using a restricted form of the locale pragma (see L<perllocale/The "use
893 locale" pragma>) like "S<C<use locale ':not_characters'>>".
895 Note that failed case-changing operations done as a result of
896 case-insensitive C</i> regular expression matching will show up in this
897 warning as having the C<fc> operation (as that is what the regular
898 expression engine calls behind the scenes.)
900 =item Can't do waitpid with flags
902 (F) This machine doesn't have either waitpid() or wait4(), so only
903 waitpid() without flags is emulated.
905 =item Can't emulate -%s on #! line
907 (F) The #! line specifies a switch that doesn't make sense at this
908 point. For example, it'd be kind of silly to put a B<-x> on the #!
911 =item Can't %s %s-endian %ss on this platform
913 (F) Your platform's byte-order is neither big-endian nor little-endian,
914 or it has a very strange pointer size. Packing and unpacking big- or
915 little-endian floating point values and pointers may not be possible.
916 See L<perlfunc/pack>.
918 =item Can't exec "%s": %s
920 (W exec) A system(), exec(), or piped open call could not execute the
921 named program for the indicated reason. Typical reasons include: the
922 permissions were wrong on the file, the file wasn't found in
923 C<$ENV{PATH}>, the executable in question was compiled for another
924 architecture, or the #! line in a script points to an interpreter that
925 can't be run for similar reasons. (Or maybe your system doesn't support
930 (F) Perl was trying to execute the indicated program for you because
931 that's what the #! line said. If that's not what you wanted, you may
932 need to mention "perl" on the #! line somewhere.
934 =item Can't execute %s
936 (F) You used the B<-S> switch, but the copies of the script to execute
937 found in the PATH did not have correct permissions.
939 =item Can't find an opnumber for "%s"
941 (F) A string of a form C<CORE::word> was given to prototype(), but there
942 is no builtin with the name C<word>.
944 =item Can't find label %s
946 (F) You said to goto a label that isn't mentioned anywhere that it's
947 possible for us to go to. See L<perlfunc/goto>.
949 =item Can't find %s on PATH
951 (F) You used the B<-S> switch, but the script to execute could not be
954 =item Can't find %s on PATH, '.' not in PATH
956 (F) You used the B<-S> switch, but the script to execute could not be
957 found in the PATH, or at least not with the correct permissions. The
958 script exists in the current directory, but PATH prohibits running it.
960 =item Can't find string terminator %s anywhere before EOF
962 (F) Perl strings can stretch over multiple lines. This message means
963 that the closing delimiter was omitted. Because bracketed quotes count
964 nesting levels, the following is missing its final parenthesis:
966 print q(The character '(' starts a side comment.);
968 If you're getting this error from a here-document, you may have
969 included unseen whitespace before or after your closing tag or there
970 may not be a linebreak after it. A good programmer's editor will have
971 a way to help you find these characters (or lack of characters). See
972 L<perlop> for the full details on here-documents.
974 =item Can't find Unicode property definition "%s"
976 =item Can't find Unicode property definition "%s" in regex; marked by <-- HERE in m/%s/
978 (F) The named property which you specified via C<\p> or C<\P> is not one
979 known to Perl. Perhaps you misspelled the name? See
980 L<perluniprops/Properties accessible through \p{} and \P{}>
981 for a complete list of available official
982 properties. If it is a
983 L<user-defined property|perlunicode/User-Defined Character Properties>
984 it must have been defined by the time the regular expression is
987 If you didn't mean to use a Unicode property, escape the C<\p>, either
988 by C<\\p> (just the C<\p>) or by C<\Q\p> (the rest of the string, or
993 (F) A fatal error occurred while trying to fork while opening a
996 =item Can't fork, trying again in 5 seconds
998 (W pipe) A fork in a piped open failed with EAGAIN and will be retried
1001 =item Can't get filespec - stale stat buffer?
1003 (S) A warning peculiar to VMS. This arises because of the difference
1004 between access checks under VMS and under the Unix model Perl assumes.
1005 Under VMS, access checks are done by filename, rather than by bits in
1006 the stat buffer, so that ACLs and other protections can be taken into
1007 account. Unfortunately, Perl assumes that the stat buffer contains all
1008 the necessary information, and passes it, instead of the filespec, to
1009 the access-checking routine. It will try to retrieve the filespec using
1010 the device name and FID present in the stat buffer, but this works only
1011 if you haven't made a subsequent call to the CRTL stat() routine,
1012 because the device name is overwritten with each call. If this warning
1013 appears, the name lookup failed, and the access-checking routine gave up
1014 and returned FALSE, just to be conservative. (Note: The access-checking
1015 routine knows about the Perl C<stat> operator and file tests, so you
1016 shouldn't ever see this warning in response to a Perl command; it arises
1017 only if some internal code takes stat buffers lightly.)
1019 =item Can't get pipe mailbox device name
1021 (P) An error peculiar to VMS. After creating a mailbox to act as a
1022 pipe, Perl can't retrieve its name for later use.
1024 =item Can't get SYSGEN parameter value for MAXBUF
1026 (P) An error peculiar to VMS. Perl asked $GETSYI how big you want your
1027 mailbox buffers to be, and didn't get an answer.
1029 =item Can't "goto" into a binary or list expression
1031 (F) A "goto" statement was executed to jump into the middle of a binary
1032 or list expression. You can't get there from here. The reason for this
1033 restriction is that the interpreter would get confused as to how many
1034 arguments there are, resulting in stack corruption or crashes. This
1035 error occurs in cases such as these:
1038 print do { F: }; # Can't jump into the arguments to print
1041 $x + do { G: $y }; # How is + supposed to get its first operand?
1043 =item Can't "goto" into a "given" block
1045 (F) A "goto" statement was executed to jump into the middle of a C<given>
1046 block. You can't get there from here. See L<perlfunc/goto>.
1048 =item Can't "goto" into the middle of a foreach loop
1050 (F) A "goto" statement was executed to jump into the middle of a foreach
1051 loop. You can't get there from here. See L<perlfunc/goto>.
1053 =item Can't "goto" out of a pseudo block
1055 (F) A "goto" statement was executed to jump out of what might look like
1056 a block, except that it isn't a proper block. This usually occurs if
1057 you tried to jump out of a sort() block or subroutine, which is a no-no.
1058 See L<perlfunc/goto>.
1060 =item Can't goto subroutine from an eval-%s
1062 (F) The "goto subroutine" call can't be used to jump out of an eval
1065 =item Can't goto subroutine from a sort sub (or similar callback)
1067 (F) The "goto subroutine" call can't be used to jump out of the
1068 comparison sub for a sort(), or from a similar callback (such
1069 as the reduce() function in List::Util).
1071 =item Can't goto subroutine outside a subroutine
1073 (F) The deeply magical "goto subroutine" call can only replace one
1074 subroutine call for another. It can't manufacture one out of whole
1075 cloth. In general you should be calling it out of only an AUTOLOAD
1076 routine anyway. See L<perlfunc/goto>.
1078 =item Can't ignore signal CHLD, forcing to default
1080 (W signal) Perl has detected that it is being run with the SIGCHLD
1081 signal (sometimes known as SIGCLD) disabled. Since disabling this
1082 signal will interfere with proper determination of exit status of child
1083 processes, Perl has reset the signal to its default value. This
1084 situation typically indicates that the parent program under which Perl
1085 may be running (e.g. cron) is being very careless.
1087 =item Can't kill a non-numeric process ID
1089 (F) Process identifiers must be (signed) integers. It is a fatal error to
1090 attempt to kill() an undefined, empty-string or otherwise non-numeric
1093 =item Can't "last" outside a loop block
1095 (F) A "last" statement was executed to break out of the current block,
1096 except that there's this itty bitty problem called there isn't a current
1097 block. Note that an "if" or "else" block doesn't count as a "loopish"
1098 block, as doesn't a block given to sort(), map() or grep(). You can
1099 usually double the curlies to get the same effect though, because the
1100 inner curlies will be considered a block that loops once. See
1103 =item Can't linearize anonymous symbol table
1105 (F) Perl tried to calculate the method resolution order (MRO) of a
1106 package, but failed because the package stash has no name.
1108 =item Can't load '%s' for module %s
1110 (F) The module you tried to load failed to load a dynamic extension.
1111 This may either mean that you upgraded your version of perl to one
1112 that is incompatible with your old dynamic extensions (which is known
1113 to happen between major versions of perl), or (more likely) that your
1114 dynamic extension was built against an older version of the library
1115 that is installed on your system. You may need to rebuild your old
1118 =item Can't localize lexical variable %s
1120 (F) You used local on a variable name that was previously declared as a
1121 lexical variable using "my" or "state". This is not allowed. If you
1122 want to localize a package variable of the same name, qualify it with
1125 =item Can't localize through a reference
1127 (F) You said something like C<local $$ref>, which Perl can't currently
1128 handle, because when it goes to restore the old value of whatever $ref
1129 pointed to after the scope of the local() is finished, it can't be sure
1130 that $ref will still be a reference.
1132 =item Can't locate %s
1134 (F) You said to C<do> (or C<require>, or C<use>) a file that couldn't be found.
1135 Perl looks for the file in all the locations mentioned in @INC, unless
1136 the file name included the full path to the file. Perhaps you need
1137 to set the PERL5LIB or PERL5OPT environment variable to say where the
1138 extra library is, or maybe the script needs to add the library name
1139 to @INC. Or maybe you just misspelled the name of the file. See
1140 L<perlfunc/require> and L<lib>.
1142 =item Can't locate auto/%s.al in @INC
1144 (F) A function (or method) was called in a package which allows
1145 autoload, but there is no function to autoload. Most probable causes
1146 are a misprint in a function/method name or a failure to C<AutoSplit>
1147 the file, say, by doing C<make install>.
1149 =item Can't locate loadable object for module %s in @INC
1151 (F) The module you loaded is trying to load an external library, like
1152 for example, F<foo.so> or F<bar.dll>, but the L<DynaLoader> module was
1153 unable to locate this library. See L<DynaLoader>.
1155 =item Can't locate object method "%s" via package "%s"
1157 (F) You called a method correctly, and it correctly indicated a package
1158 functioning as a class, but that package doesn't define that particular
1159 method, nor does any of its base classes. See L<perlobj>.
1161 =item Can't locate object method "%s" via package "%s" (perhaps you forgot
1164 (F) You called a method on a class that did not exist, and the method
1165 could not be found in UNIVERSAL. This often means that a method
1166 requires a package that has not been loaded.
1168 =item Can't locate package %s for @%s::ISA
1170 (W syntax) The @ISA array contained the name of another package that
1171 doesn't seem to exist.
1173 =item Can't locate PerlIO%s
1175 (F) You tried to use in open() a PerlIO layer that does not exist,
1176 e.g. open(FH, ">:nosuchlayer", "somefile").
1178 =item Can't make list assignment to %ENV on this system
1180 (F) List assignment to %ENV is not supported on some systems, notably
1183 =item Can't make loaded symbols global on this platform while loading %s
1185 (S) A module passed the flag 0x01 to DynaLoader::dl_load_file() to request
1186 that symbols from the stated file are made available globally within the
1187 process, but that functionality is not available on this platform. Whilst
1188 the module likely will still work, this may prevent the perl interpreter
1189 from loading other XS-based extensions which need to link directly to
1190 functions defined in the C or XS code in the stated file.
1192 =item Can't modify %s in %s
1194 (F) You aren't allowed to assign to the item indicated, or otherwise try
1195 to change it, such as with an auto-increment.
1197 =item Can't modify nonexistent substring
1199 (P) The internal routine that does assignment to a substr() was handed
1202 =item Can't modify non-lvalue subroutine call of &%s
1204 =item Can't modify non-lvalue subroutine call of &%s in %s
1206 (F) Subroutines meant to be used in lvalue context should be declared as
1207 such. See L<perlsub/"Lvalue subroutines">.
1209 =item Can't modify reference to %s in %s assignment
1211 (F) Only a limited number of constructs can be used as the argument to a
1212 reference constructor on the left-hand side of an assignment, and what
1213 you used was not one of them. See L<perlref/Assigning to References>.
1215 =item Can't modify reference to localized parenthesized array in list
1218 (F) Assigning to C<\local(@array)> or C<\(local @array)> is not supported, as
1219 it is not clear exactly what it should do. If you meant to make @array
1220 refer to some other array, use C<\@array = \@other_array>. If you want to
1221 make the elements of @array aliases of the scalars referenced on the
1222 right-hand side, use C<\(@array) = @scalar_refs>.
1224 =item Can't modify reference to parenthesized hash in list assignment
1226 (F) Assigning to C<\(%hash)> is not supported. If you meant to make %hash
1227 refer to some other hash, use C<\%hash = \%other_hash>. If you want to
1228 make the elements of %hash into aliases of the scalars referenced on the
1229 right-hand side, use a hash slice: C<\@hash{@keys} = @those_scalar_refs>.
1231 =item Can't msgrcv to read-only var
1233 (F) The target of a msgrcv must be modifiable to be used as a receive
1236 =item Can't "next" outside a loop block
1238 (F) A "next" statement was executed to reiterate the current block, but
1239 there isn't a current block. Note that an "if" or "else" block doesn't
1240 count as a "loopish" block, as doesn't a block given to sort(), map() or
1241 grep(). You can usually double the curlies to get the same effect
1242 though, because the inner curlies will be considered a block that loops
1243 once. See L<perlfunc/next>.
1245 =item Can't open %s: %s
1247 (S inplace) The implicit opening of a file through use of the C<< <> >>
1248 filehandle, either implicitly under the C<-n> or C<-p> command-line
1249 switches, or explicitly, failed for the indicated reason. Usually
1250 this is because you don't have read permission for a file which
1251 you named on the command line.
1253 (F) You tried to call perl with the B<-e> switch, but F</dev/null> (or
1254 your operating system's equivalent) could not be opened.
1256 =item Can't open a reference
1258 (W io) You tried to open a scalar reference for reading or writing,
1259 using the 3-arg open() syntax:
1263 but your version of perl is compiled without perlio, and this form of
1264 open is not supported.
1266 =item Can't open bidirectional pipe
1268 (W pipe) You tried to say C<open(CMD, "|cmd|")>, which is not supported.
1269 You can try any of several modules in the Perl library to do this, such
1270 as IPC::Open2. Alternately, direct the pipe's output to a file using
1271 ">", and then read it in under a different file handle.
1273 =item Can't open error file %s as stderr
1275 (F) An error peculiar to VMS. Perl does its own command line
1276 redirection, and couldn't open the file specified after '2>' or '2>>' on
1277 the command line for writing.
1279 =item Can't open input file %s as stdin
1281 (F) An error peculiar to VMS. Perl does its own command line
1282 redirection, and couldn't open the file specified after '<' on the
1283 command line for reading.
1285 =item Can't open output file %s as stdout
1287 (F) An error peculiar to VMS. Perl does its own command line
1288 redirection, and couldn't open the file specified after '>' or '>>' on
1289 the command line for writing.
1291 =item Can't open output pipe (name: %s)
1293 (P) An error peculiar to VMS. Perl does its own command line
1294 redirection, and couldn't open the pipe into which to send data destined
1297 =item Can't open perl script "%s": %s
1299 (F) The script you specified can't be opened for the indicated reason.
1301 If you're debugging a script that uses #!, and normally relies on the
1302 shell's $PATH search, the -S option causes perl to do that search, so
1303 you don't have to type the path or C<`which $scriptname`>.
1305 =item Can't read CRTL environ
1307 (S) A warning peculiar to VMS. Perl tried to read an element of %ENV
1308 from the CRTL's internal environment array and discovered the array was
1309 missing. You need to figure out where your CRTL misplaced its environ
1310 or define F<PERL_ENV_TABLES> (see L<perlvms>) so that environ is not
1313 =item Can't redeclare "%s" in "%s"
1315 (F) A "my", "our" or "state" declaration was found within another declaration,
1316 such as C<my ($x, my($y), $z)> or C<our (my $x)>.
1318 =item Can't "redo" outside a loop block
1320 (F) A "redo" statement was executed to restart the current block, but
1321 there isn't a current block. Note that an "if" or "else" block doesn't
1322 count as a "loopish" block, as doesn't a block given to sort(), map()
1323 or grep(). You can usually double the curlies to get the same effect
1324 though, because the inner curlies will be considered a block that
1325 loops once. See L<perlfunc/redo>.
1327 =item Can't remove %s: %s, skipping file
1329 (S inplace) You requested an inplace edit without creating a backup
1330 file. Perl was unable to remove the original file to replace it with
1331 the modified file. The file was left unmodified.
1333 =item Can't rename in-place work file '%s' to '%s': %s
1335 (F) When closed implicitly, the temporary file for in-place editing
1336 couldn't be renamed to the original filename.
1338 =item Can't rename %s to %s: %s, skipping file
1340 (F) The rename done by the B<-i> switch failed for some reason,
1341 probably because you don't have write permission to the directory.
1343 =item Can't reopen input pipe (name: %s) in binary mode
1345 (P) An error peculiar to VMS. Perl thought stdin was a pipe, and tried
1346 to reopen it to accept binary data. Alas, it failed.
1348 =item Can't represent character for Ox%X on this platform
1350 (F) There is a hard limit to how big a character code point can be due
1351 to the fundamental properties of UTF-8, especially on EBCDIC
1352 platforms. The given code point exceeds that. The only work-around is
1353 to not use such a large code point.
1355 =item Can't reset %ENV on this system
1357 (F) You called C<reset('E')> or similar, which tried to reset
1358 all variables in the current package beginning with "E". In
1359 the main package, that includes %ENV. Resetting %ENV is not
1360 supported on some systems, notably VMS.
1362 =item Can't resolve method "%s" overloading "%s" in package "%s"
1364 (F)(P) Error resolving overloading specified by a method name (as
1365 opposed to a subroutine reference): no such method callable via the
1366 package. If the method name is C<???>, this is an internal error.
1368 =item Can't return %s from lvalue subroutine
1370 (F) Perl detected an attempt to return illegal lvalues (such as
1371 temporary or readonly values) from a subroutine used as an lvalue. This
1374 =item Can't return outside a subroutine
1376 (F) The return statement was executed in mainline code, that is, where
1377 there was no subroutine call to return out of. See L<perlsub>.
1379 =item Can't return %s to lvalue scalar context
1381 (F) You tried to return a complete array or hash from an lvalue
1382 subroutine, but you called the subroutine in a way that made Perl
1383 think you meant to return only one value. You probably meant to
1384 write parentheses around the call to the subroutine, which tell
1385 Perl that the call should be in list context.
1387 =item Can't stat script "%s"
1389 (P) For some reason you can't fstat() the script even though you have it
1390 open already. Bizarre.
1392 =item Can't take log of %g
1394 (F) For ordinary real numbers, you can't take the logarithm of a
1395 negative number or zero. There's a Math::Complex package that comes
1396 standard with Perl, though, if you really want to do that for the
1399 =item Can't take sqrt of %g
1401 (F) For ordinary real numbers, you can't take the square root of a
1402 negative number. There's a Math::Complex package that comes standard
1403 with Perl, though, if you really want to do that.
1405 =item Can't undef active subroutine
1407 (F) You can't undefine a routine that's currently running. You can,
1408 however, redefine it while it's running, and you can even undef the
1409 redefined subroutine while the old routine is running. Go figure.
1411 =item Can't unweaken a nonreference
1413 (F) You attempted to unweaken something that was not a reference. Only
1414 references can be unweakened.
1416 =item Can't upgrade %s (%d) to %d
1418 (P) The internal sv_upgrade routine adds "members" to an SV, making it
1419 into a more specialized kind of SV. The top several SV types are so
1420 specialized, however, that they cannot be interconverted. This message
1421 indicates that such a conversion was attempted.
1423 =item Can't use '%c' after -mname
1425 (F) You tried to call perl with the B<-m> switch, but you put something
1426 other than "=" after the module name.
1428 =item Can't use a hash as a reference
1430 (F) You tried to use a hash as a reference, as in
1431 C<< %foo->{"bar"} >> or C<< %$ref->{"hello"} >>. Versions of perl
1432 <= 5.22.0 used to allow this syntax, but shouldn't
1433 have. This was deprecated in perl 5.6.1.
1435 =item Can't use an array as a reference
1437 (F) You tried to use an array as a reference, as in
1438 C<< @foo->[23] >> or C<< @$ref->[99] >>. Versions of perl <= 5.22.0
1439 used to allow this syntax, but shouldn't have. This
1440 was deprecated in perl 5.6.1.
1442 =item Can't use anonymous symbol table for method lookup
1444 (F) The internal routine that does method lookup was handed a symbol
1445 table that doesn't have a name. Symbol tables can become anonymous
1446 for example by undefining stashes: C<undef %Some::Package::>.
1448 =item Can't use an undefined value as %s reference
1450 (F) A value used as either a hard reference or a symbolic reference must
1451 be a defined value. This helps to delurk some insidious errors.
1453 =item Can't use bareword ("%s") as %s ref while "strict refs" in use
1455 (F) Only hard references are allowed by "strict refs". Symbolic
1456 references are disallowed. See L<perlref>.
1458 =item Can't use %! because Errno.pm is not available
1460 (F) The first time the C<%!> hash is used, perl automatically loads the
1461 Errno.pm module. The Errno module is expected to tie the %! hash to
1462 provide symbolic names for C<$!> errno values.
1464 =item Can't use both '<' and '>' after type '%c' in %s
1466 (F) A type cannot be forced to have both big-endian and little-endian
1467 byte-order at the same time, so this combination of modifiers is not
1468 allowed. See L<perlfunc/pack>.
1470 =item Can't use 'defined(@array)' (Maybe you should just omit the defined()?)
1472 (F) defined() is not useful on arrays because it
1473 checks for an undefined I<scalar> value. If you want to see if the
1474 array is empty, just use C<if (@array) { # not empty }> for example.
1476 =item Can't use 'defined(%hash)' (Maybe you should just omit the defined()?)
1478 (F) C<defined()> is not usually right on hashes.
1480 Although C<defined %hash> is false on a plain not-yet-used hash, it
1481 becomes true in several non-obvious circumstances, including iterators,
1482 weak references, stash names, even remaining true after C<undef %hash>.
1483 These things make C<defined %hash> fairly useless in practice, so it now
1484 generates a fatal error.
1486 If a check for non-empty is what you wanted then just put it in boolean
1487 context (see L<perldata/Scalar values>):
1493 If you had C<defined %Foo::Bar::QUUX> to check whether such a package
1494 variable exists then that's never really been reliable, and isn't
1495 a good way to enquire about the features of a package, or whether
1498 =item Can't use %s for loop variable
1500 (P) The parser got confused when trying to parse a C<foreach> loop.
1502 =item Can't use global %s in %s
1504 (F) You tried to declare a magical variable as a lexical variable. This
1505 is not allowed, because the magic can be tied to only one location
1506 (namely the global variable) and it would be incredibly confusing to
1507 have variables in your program that looked like magical variables but
1510 =item Can't use '%c' in a group with different byte-order in %s
1512 (F) You attempted to force a different byte-order on a type
1513 that is already inside a group with a byte-order modifier.
1514 For example you cannot force little-endianness on a type that
1515 is inside a big-endian group.
1517 =item Can't use "my %s" in sort comparison
1519 (F) The global variables $a and $b are reserved for sort comparisons.
1520 You mentioned $a or $b in the same line as the <=> or cmp operator,
1521 and the variable had earlier been declared as a lexical variable.
1522 Either qualify the sort variable with the package name, or rename the
1525 =item Can't use %s ref as %s ref
1527 (F) You've mixed up your reference types. You have to dereference a
1528 reference of the type needed. You can use the ref() function to
1529 test the type of the reference, if need be.
1531 =item Can't use string ("%s") as %s ref while "strict refs" in use
1533 =item Can't use string ("%s"...) as %s ref while "strict refs" in use
1535 (F) You've told Perl to dereference a string, something which
1536 C<use strict> blocks to prevent it happening accidentally. See
1537 L<perlref/"Symbolic references">. This can be triggered by an C<@> or C<$>
1538 in a double-quoted string immediately before interpolating a variable,
1539 for example in C<"user @$twitter_id">, which says to treat the contents
1540 of C<$twitter_id> as an array reference; use a C<\> to have a literal C<@>
1541 symbol followed by the contents of C<$twitter_id>: C<"user \@$twitter_id">.
1543 =item Can't use subscript on %s
1545 (F) The compiler tried to interpret a bracketed expression as a
1546 subscript. But to the left of the brackets was an expression that
1547 didn't look like a hash or array reference, or anything else subscriptable.
1549 =item Can't use \%c to mean $%c in expression
1551 (W syntax) In an ordinary expression, backslash is a unary operator that
1552 creates a reference to its argument. The use of backslash to indicate a
1553 backreference to a matched substring is valid only as part of a regular
1554 expression pattern. Trying to do this in ordinary Perl code produces a
1555 value that prints out looking like SCALAR(0xdecaf). Use the $1 form
1558 =item Can't weaken a nonreference
1560 (F) You attempted to weaken something that was not a reference. Only
1561 references can be weakened.
1563 =item Can't "when" outside a topicalizer
1565 (F) You have used a when() block that is neither inside a C<foreach>
1566 loop nor a C<given> block. (Note that this error is issued on exit
1567 from the C<when> block, so you won't get the error if the match fails,
1568 or if you use an explicit C<continue>.)
1570 =item Can't x= to read-only value
1572 (F) You tried to repeat a constant value (often the undefined value)
1573 with an assignment operator, which implies modifying the value itself.
1574 Perhaps you need to copy the value to a temporary, and repeat that.
1576 =item Character following "\c" must be printable ASCII
1578 (F) In C<\cI<X>>, I<X> must be a printable (non-control) ASCII character.
1580 Note that ASCII characters that don't map to control characters are
1581 discouraged, and will generate the warning (when enabled)
1582 L</""\c%c" is more clearly written simply as "%s"">.
1584 =item Character following \%c must be '{' or a single-character Unicode property name in regex; marked by <-- HERE in m/%s/
1586 (F) (In the above the C<%c> is replaced by either C<p> or C<P>.) You
1587 specified something that isn't a legal Unicode property name. Most
1588 Unicode properties are specified by C<\p{...}>. But if the name is a
1589 single character one, the braces may be omitted.
1591 =item Character in 'C' format wrapped in pack
1597 where $x is either less than 0 or more than 255; the C<"C"> format is
1598 only for encoding native operating system characters (ASCII, EBCDIC,
1599 and so on) and not for Unicode characters, so Perl behaved as if you meant
1603 If you actually want to pack Unicode codepoints, use the C<"U"> format
1606 =item Character in 'c' format wrapped in pack
1612 where $x is either less than -128 or more than 127; the C<"c"> format
1613 is only for encoding native operating system characters (ASCII, EBCDIC,
1614 and so on) and not for Unicode characters, so Perl behaved as if you meant
1616 pack("c", $x & 255);
1618 If you actually want to pack Unicode codepoints, use the C<"U"> format
1621 =item Character in '%c' format wrapped in unpack
1623 (W unpack) You tried something like
1625 unpack("H", "\x{2a1}")
1627 where the format expects to process a byte (a character with a value
1628 below 256), but a higher value was provided instead. Perl uses the
1629 value modulus 256 instead, as if you had provided:
1631 unpack("H", "\x{a1}")
1633 =item Character in 'W' format wrapped in pack
1639 where $x is either less than 0 or more than 255. However, C<U0>-mode
1640 expects all values to fall in the interval [0, 255], so Perl behaved
1643 pack("U0W", $x & 255)
1645 =item Character(s) in '%c' format wrapped in pack
1647 (W pack) You tried something like
1649 pack("u", "\x{1f3}b")
1651 where the format expects to process a sequence of bytes (character with a
1652 value below 256), but some of the characters had a higher value. Perl
1653 uses the character values modulus 256 instead, as if you had provided:
1655 pack("u", "\x{f3}b")
1657 =item Character(s) in '%c' format wrapped in unpack
1659 (W unpack) You tried something like
1661 unpack("s", "\x{1f3}b")
1663 where the format expects to process a sequence of bytes (character with a
1664 value below 256), but some of the characters had a higher value. Perl
1665 uses the character values modulus 256 instead, as if you had provided:
1667 unpack("s", "\x{f3}b")
1669 =item charnames alias definitions may not contain a sequence of multiple
1670 spaces; marked by S<<-- HERE> in %s
1672 (F) You defined a character name which had multiple space characters
1673 in a row. Change them to single spaces. Usually these names are
1674 defined in the C<:alias> import argument to C<use charnames>, but they
1675 could be defined by a translator installed into C<$^H{charnames}>. See
1676 L<charnames/CUSTOM ALIASES>.
1678 =item charnames alias definitions may not contain trailing white-space;
1679 marked by S<<-- HERE> in %s
1681 (F) You defined a character name which ended in a space
1682 character. Remove the trailing space(s). Usually these names are
1683 defined in the C<:alias> import argument to C<use charnames>, but they
1684 could be defined by a translator installed into C<$^H{charnames}>.
1685 See L<charnames/CUSTOM ALIASES>.
1687 =item chdir() on unopened filehandle %s
1689 (W unopened) You tried chdir() on a filehandle that was never opened.
1691 =item "\c%c" is more clearly written simply as "%s"
1693 (W syntax) The C<\cI<X>> construct is intended to be a way to specify
1694 non-printable characters. You used it for a printable one, which
1695 is better written as simply itself, perhaps preceded by a backslash
1696 for non-word characters. Doing it the way you did is not portable
1697 between ASCII and EBCDIC platforms.
1699 =item Cloning substitution context is unimplemented
1701 (F) Creating a new thread inside the C<s///> operator is not supported.
1703 =item closedir() attempted on invalid dirhandle %s
1705 (W io) The dirhandle you tried to close is either closed or not really
1706 a dirhandle. Check your control flow.
1708 =item close() on unopened filehandle %s
1710 (W unopened) You tried to close a filehandle that was never opened.
1712 =item Closure prototype called
1714 (F) If a closure has attributes, the subroutine passed to an attribute
1715 handler is the prototype that is cloned when a new closure is created.
1716 This subroutine cannot be called.
1718 =item \C no longer supported in regex; marked by S<<-- HERE> in m/%s/
1720 (F) The \C character class used to allow a match of single byte
1721 within a multi-byte utf-8 character, but was removed in v5.24 as
1722 it broke encapsulation and its implementation was extremely buggy.
1723 If you really need to process the individual bytes, you probably
1724 want to convert your string to one where each underlying byte is
1725 stored as a character, with utf8::encode().
1727 =item Code missing after '/'
1729 (F) You had a (sub-)template that ends with a '/'. There must be
1730 another template code following the slash. See L<perlfunc/pack>.
1732 =item Code point 0x%X is not Unicode, and not portable
1734 (S non_unicode portable) You had a code point that has never been in any
1735 standard, so it is likely that languages other than Perl will NOT
1736 understand it. This code point also will not fit in a 32-bit word on
1737 ASCII platforms and therefore is non-portable between systems.
1739 At one time, it was legal in some standards to have code points up to
1740 0x7FFF_FFFF, but not higher, and this code point is higher.
1742 Acceptance of these code points is a Perl extension, and you should
1743 expect that nothing other than Perl can handle them; Perl itself on
1744 EBCDIC platforms before v5.24 does not handle them.
1746 Perl also makes no guarantees that the representation of these code
1747 points won't change at some point in the future, say when machines
1748 become available that have larger than a 64-bit word. At that time,
1749 files containing any of these, written by an older Perl might require
1750 conversion before being readable by a newer Perl.
1752 =item Code point 0x%X is not Unicode, may not be portable
1754 (S non_unicode) You had a code point above the Unicode maximum
1757 Perl allows strings to contain a superset of Unicode code points, but
1758 these may not be accepted by other languages/systems. Further, even if
1759 these languages/systems accept these large code points, they may have
1760 chosen a different representation for them than the UTF-8-like one that
1761 Perl has, which would mean files are not exchangeable between them and
1764 On EBCDIC platforms, code points above 0x3FFF_FFFF have a different
1765 representation in Perl v5.24 than before, so any file containing these
1766 that was written before that version will require conversion before
1767 being readable by a later Perl.
1769 =item %s: Command not found
1771 (A) You've accidentally run your script through B<csh> or another shell
1772 instead of Perl. Check the #! line, or manually feed your script into
1773 Perl yourself. The #! line at the top of your file could look like
1777 =item %s: command not found
1779 (A) You've accidentally run your script through B<bash> or another shell
1780 instead of Perl. Check the #! line, or manually feed your script into
1781 Perl yourself. The #! line at the top of your file could look like
1785 =item %s: command not found: %s
1787 (A) You've accidentally run your script through B<zsh> or another shell
1788 instead of Perl. Check the #! line, or manually feed your script into
1789 Perl yourself. The #! line at the top of your file could look like
1793 =item Compilation failed in require
1795 (F) Perl could not compile a file specified in a C<require> statement.
1796 Perl uses this generic message when none of the errors that it
1797 encountered were severe enough to halt compilation immediately.
1799 =item Complex regular subexpression recursion limit (%d) exceeded
1801 (W regexp) The regular expression engine uses recursion in complex
1802 situations where back-tracking is required. Recursion depth is limited
1803 to 32766, or perhaps less in architectures where the stack cannot grow
1804 arbitrarily. ("Simple" and "medium" situations are handled without
1805 recursion and are not subject to a limit.) Try shortening the string
1806 under examination; looping in Perl code (e.g. with C<while>) rather than
1807 in the regular expression engine; or rewriting the regular expression so
1808 that it is simpler or backtracks less. (See L<perlfaq2> for information
1809 on I<Mastering Regular Expressions>.)
1811 =item connect() on closed socket %s
1813 (W closed) You tried to do a connect on a closed socket. Did you forget
1814 to check the return value of your socket() call? See
1815 L<perlfunc/connect>.
1817 =item Constant(%s): Call to &{$^H{%s}} did not return a defined value
1819 (F) The subroutine registered to handle constant overloading
1820 (see L<overload>) or a custom charnames handler (see
1821 L<charnames/CUSTOM TRANSLATORS>) returned an undefined value.
1823 =item Constant(%s): $^H{%s} is not defined
1825 (F) The parser found inconsistencies while attempting to define an
1826 overloaded constant. Perhaps you forgot to load the corresponding
1829 =item Constant is not %s reference
1831 (F) A constant value (perhaps declared using the C<use constant> pragma)
1832 is being dereferenced, but it amounts to the wrong type of reference.
1833 The message indicates the type of reference that was expected. This
1834 usually indicates a syntax error in dereferencing the constant value.
1835 See L<perlsub/"Constant Functions"> and L<constant>.
1837 =item Constants from lexical variables potentially modified elsewhere are no longer permitted
1839 (F) You wrote something like
1842 $sub = sub () { $var };
1844 but $var is referenced elsewhere and could be modified after the C<sub>
1845 expression is evaluated. Either it is explicitly modified elsewhere
1846 (C<$var = 3>) or it is passed to a subroutine or to an operator like
1847 C<printf> or C<map>, which may or may not modify the variable.
1849 Traditionally, Perl has captured the value of the variable at that
1850 point and turned the subroutine into a constant eligible for inlining.
1851 In those cases where the variable can be modified elsewhere, this
1852 breaks the behavior of closures, in which the subroutine captures
1853 the variable itself, rather than its value, so future changes to the
1854 variable are reflected in the subroutine's return value.
1856 This usage was deprecated, and as of Perl 5.32 is no longer allowed,
1857 making it possible to change the behavior in the future.
1859 If you intended for the subroutine to be eligible for inlining, then
1860 make sure the variable is not referenced elsewhere, possibly by
1864 $sub = sub () { $var2 };
1866 If you do want this subroutine to be a closure that reflects future
1867 changes to the variable that it closes over, add an explicit C<return>:
1870 $sub = sub () { return $var };
1872 =item Constant subroutine %s redefined
1874 (W redefine)(S) You redefined a subroutine which had previously
1875 been eligible for inlining. See L<perlsub/"Constant Functions">
1876 for commentary and workarounds.
1878 =item Constant subroutine %s undefined
1880 (W misc) You undefined a subroutine which had previously been eligible
1881 for inlining. See L<perlsub/"Constant Functions"> for commentary and
1884 =item Constant(%s) unknown
1886 (F) The parser found inconsistencies either while attempting
1887 to define an overloaded constant, or when trying to find the
1888 character name specified in the C<\N{...}> escape. Perhaps you
1889 forgot to load the corresponding L<overload> pragma?
1891 =item :const is experimental
1893 (S experimental::const_attr) The "const" attribute is experimental.
1894 If you want to use the feature, disable the warning with C<no warnings
1895 'experimental::const_attr'>, but know that in doing so you are taking
1896 the risk that your code may break in a future Perl version.
1898 =item :const is not permitted on named subroutines
1900 (F) The "const" attribute causes an anonymous subroutine to be run and
1901 its value captured at the time that it is cloned. Named subroutines are
1902 not cloned like this, so the attribute does not make sense on them.
1904 =item Copy method did not return a reference
1906 (F) The method which overloads "=" is buggy. See
1907 L<overload/Copy Constructor>.
1909 =item &CORE::%s cannot be called directly
1911 (F) You tried to call a subroutine in the C<CORE::> namespace
1912 with C<&foo> syntax or through a reference. Some subroutines
1913 in this package cannot yet be called that way, but must be
1914 called as barewords. Something like this will work:
1916 BEGIN { *shove = \&CORE::push; }
1917 shove @array, 1,2,3; # pushes on to @array
1919 =item CORE::%s is not a keyword
1921 (F) The CORE:: namespace is reserved for Perl keywords.
1923 =item Corrupted regexp opcode %d > %d
1925 (P) This is either an error in Perl, or, if you're using
1926 one, your L<custom regular expression engine|perlreapi>. If not the
1927 latter, report the problem to L<https://github.com/Perl/perl5/issues>.
1929 =item corrupted regexp pointers
1931 (P) The regular expression engine got confused by what the regular
1932 expression compiler gave it.
1934 =item corrupted regexp program
1936 (P) The regular expression engine got passed a regexp program without a
1939 =item Corrupt malloc ptr 0x%x at 0x%x
1941 (P) The malloc package that comes with Perl had an internal failure.
1943 =item Count after length/code in unpack
1945 (F) You had an unpack template indicating a counted-length string, but
1946 you have also specified an explicit size for the string. See
1949 =item Declaring references is experimental
1951 (S experimental::declared_refs) This warning is emitted if you use
1952 a reference constructor on the right-hand side of C<my>, C<state>, C<our>, or
1953 C<local>. Simply suppress the warning if you want to use the feature, but
1954 know that in doing so you are taking the risk of using an experimental
1955 feature which may change or be removed in a future Perl version:
1957 no warnings "experimental::declared_refs";
1958 use feature "declared_refs";
1962 The following are used in lib/diagnostics.t for testing two =items that
1963 share the same description. Changes here need to be propagated to there
1965 =item Deep recursion on anonymous subroutine
1967 =item Deep recursion on subroutine "%s"
1969 (W recursion) This subroutine has called itself (directly or indirectly)
1970 100 times more than it has returned. This probably indicates an
1971 infinite recursion, unless you're writing strange benchmark programs, in
1972 which case it indicates something else.
1974 This threshold can be changed from 100, by recompiling the F<perl> binary,
1975 setting the C pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value.
1977 =item (?(DEFINE)....) does not allow branches in regex; marked by
1978 S<<-- HERE> in m/%s/
1980 (F) You used something like C<(?(DEFINE)...|..)> which is illegal. The
1981 most likely cause of this error is that you left out a parenthesis inside
1982 of the C<....> part.
1984 The S<<-- HERE> shows whereabouts in the regular expression the problem was
1987 =item %s defines neither package nor VERSION--version check failed
1989 (F) You said something like "use Module 42" but in the Module file
1990 there are neither package declarations nor a C<$VERSION>.
1992 =item delete argument is not a HASH or ARRAY element or slice
1994 (F) The argument to C<delete> must be either a hash or array element,
2000 or a hash or array slice, such as:
2002 @foo[$bar, $baz, $xyzzy]
2003 $ref->[12]->@{"susie", "queue"}
2005 or a hash key/value or array index/value slice, such as:
2007 %foo[$bar, $baz, $xyzzy]
2008 $ref->[12]->%{"susie", "queue"}
2010 =item Delimiter for here document is too long
2012 (F) In a here document construct like C<<<FOO>, the label C<FOO> is too
2013 long for Perl to handle. You have to be seriously twisted to write code
2014 that triggers this error.
2016 =item Deprecated use of my() in false conditional. This will be a fatal error in Perl 5.30
2018 (D deprecated) You used a declaration similar to C<my $x if 0>. There
2019 has been a long-standing bug in Perl that causes a lexical variable
2020 not to be cleared at scope exit when its declaration includes a false
2021 conditional. Some people have exploited this bug to achieve a kind of
2022 static variable. Since we intend to fix this bug, we don't want people
2023 relying on this behavior. You can achieve a similar static effect by
2024 declaring the variable in a separate block outside the function, eg
2026 sub f { my $x if 0; return $x++ }
2030 { my $x; sub f { return $x++ } }
2032 Beginning with perl 5.10.0, you can also use C<state> variables to have
2033 lexicals that are initialized only once (see L<feature>):
2035 sub f { state $x; return $x++ }
2037 This use of C<my()> in a false conditional has been deprecated since
2038 Perl 5.10, and it will become a fatal error in Perl 5.30.
2040 =item DESTROY created new reference to dead object '%s'
2042 (F) A DESTROY() method created a new reference to the object which is
2043 just being DESTROYed. Perl is confused, and prefers to abort rather
2044 than to create a dangling reference.
2046 =item Did not produce a valid header
2048 See L</500 Server error>.
2050 =item %s did not return a true value
2052 (F) A required (or used) file must return a true value to indicate that
2053 it compiled correctly and ran its initialization code correctly. It's
2054 traditional to end such a file with a "1;", though any true value would
2055 do. See L<perlfunc/require>.
2057 =item (Did you mean &%s instead?)
2059 (W misc) You probably referred to an imported subroutine &FOO as $FOO or
2062 =item (Did you mean "local" instead of "our"?)
2064 (W shadow) Remember that "our" does not localize the declared global
2065 variable. You have declared it again in the same lexical scope, which
2068 =item (Did you mean $ or @ instead of %?)
2070 (W) You probably said %hash{$key} when you meant $hash{$key} or
2071 @hash{@keys}. On the other hand, maybe you just meant %hash and got
2076 (F) You passed die() an empty string (the equivalent of C<die "">) or
2077 you called it with no args and C<$@> was empty.
2079 =item Document contains no data
2081 See L</500 Server error>.
2083 =item %s does not define %s::VERSION--version check failed
2085 (F) You said something like "use Module 42" but the Module did not
2086 define a C<$VERSION>.
2088 =item '/' does not take a repeat count
2090 (F) You cannot put a repeat count of any kind right after the '/' code.
2091 See L<perlfunc/pack>.
2093 =item do "%s" failed, '.' is no longer in @INC; did you mean do "./%s"?
2095 (D deprecated) Previously C< do "somefile"; > would search the current
2096 directory for the specified file. Since perl v5.26.0, F<.> has been
2097 removed from C<@INC> by default, so this is no longer true. To search the
2098 current directory (and only the current directory) you can write
2099 C< do "./somefile"; >.
2101 =item Don't know how to get file name
2103 (P) C<PerlIO_getname>, a perl internal I/O function specific to VMS, was
2104 somehow called on another platform. This should not happen.
2106 =item Don't know how to handle magic of type \%o
2108 (P) The internal handling of magical variables has been cursed.
2110 =item do_study: out of memory
2112 (P) This should have been caught by safemalloc() instead.
2114 =item (Do you need to predeclare %s?)
2116 (S syntax) This is an educated guess made in conjunction with the message
2117 "%s found where operator expected". It often means a subroutine or module
2118 name is being referenced that hasn't been declared yet. This may be
2119 because of ordering problems in your file, or because of a missing
2120 "sub", "package", "require", or "use" statement. If you're referencing
2121 something that isn't defined yet, you don't actually have to define the
2122 subroutine or package before the current location. You can use an empty
2123 "sub foo;" or "package FOO;" to enter a "forward" declaration.
2125 =item dump() must be written as CORE::dump() as of Perl 5.30
2127 (F) You used the obsolete C<dump()> built-in function. That was deprecated in
2128 Perl 5.8.0. As of Perl 5.30 it must be written in fully qualified format:
2131 See L<perlfunc/dump>.
2133 =item dump is not supported
2135 (F) Your machine doesn't support dump/undump.
2137 =item Duplicate free() ignored
2139 (S malloc) An internal routine called free() on something that had
2142 =item Duplicate modifier '%c' after '%c' in %s
2144 (W unpack) You have applied the same modifier more than once after a
2145 type in a pack template. See L<perlfunc/pack>.
2147 =item elseif should be elsif
2149 (S syntax) There is no keyword "elseif" in Perl because Larry thinks
2150 it's ugly. Your code will be interpreted as an attempt to call a method
2151 named "elseif" for the class returned by the following block. This is
2152 unlikely to be what you want.
2154 =item Empty \%c in regex; marked by S<<-- HERE> in m/%s/
2158 =item Empty \%c{} in regex; marked by S<<-- HERE> in m/%s/
2160 (F) You used something like C<\b{}>, C<\B{}>, C<\o{}>, C<\p>, C<\P>, or
2161 C<\x> without specifying anything for it to operate on.
2163 Unfortunately, for backwards compatibility reasons, an empty C<\x> is
2164 legal outside S<C<use re 'strict'>> and expands to a NUL character.
2166 =item Empty (?) without any modifiers in regex; marked by <-- HERE in m/%s/
2168 (W regexp) (only under C<S<use re 'strict'>>)
2169 C<(?)> does nothing, so perhaps this is a typo.
2171 =item ${^ENCODING} is no longer supported
2173 (F) The special variable C<${^ENCODING}>, formerly used to implement
2174 the C<encoding> pragma, is no longer supported as of Perl 5.26.0.
2176 Setting it to anything other than C<undef> is a fatal error as of Perl
2179 =item entering effective %s failed
2181 (F) While under the C<use filetest> pragma, switching the real and
2182 effective uids or gids failed.
2184 =item %ENV is aliased to %s
2186 (F) You're running under taint mode, and the C<%ENV> variable has been
2187 aliased to another hash, so it doesn't reflect anymore the state of the
2188 program's environment. This is potentially insecure.
2190 =item Error converting file specification %s
2192 (F) An error peculiar to VMS. Because Perl may have to deal with file
2193 specifications in either VMS or Unix syntax, it converts them to a
2194 single form when it must operate on them directly. Either you've passed
2195 an invalid file specification to Perl, or you've found a case the
2196 conversion routines don't handle. Drat.
2198 =item Eval-group in insecure regular expression
2200 (F) Perl detected tainted data when trying to compile a regular
2201 expression that contains the C<(?{ ... })> zero-width assertion, which
2202 is unsafe. See L<perlre/(?{ code })>, and L<perlsec>.
2204 =item Eval-group not allowed at runtime, use re 'eval' in regex m/%s/
2206 (F) Perl tried to compile a regular expression containing the
2207 C<(?{ ... })> zero-width assertion at run time, as it would when the
2208 pattern contains interpolated values. Since that is a security risk,
2209 it is not allowed. If you insist, you may still do this by using the
2210 C<re 'eval'> pragma or by explicitly building the pattern from an
2211 interpolated string at run time and using that in an eval(). See
2212 L<perlre/(?{ code })>.
2214 =item Eval-group not allowed, use re 'eval' in regex m/%s/
2216 (F) A regular expression contained the C<(?{ ... })> zero-width
2217 assertion, but that construct is only allowed when the C<use re 'eval'>
2218 pragma is in effect. See L<perlre/(?{ code })>.
2220 =item EVAL without pos change exceeded limit in regex; marked by
2221 S<<-- HERE> in m/%s/
2223 (F) You used a pattern that nested too many EVAL calls without consuming
2224 any text. Restructure the pattern so that text is consumed.
2226 The S<<-- HERE> shows whereabouts in the regular expression the problem was
2229 =item Excessively long <> operator
2231 (F) The contents of a <> operator may not exceed the maximum size of a
2232 Perl identifier. If you're just trying to glob a long list of
2233 filenames, try using the glob() operator, or put the filenames into a
2234 variable and glob that.
2236 =item exec? I'm not *that* kind of operating system
2238 (F) The C<exec> function is not implemented on some systems, e.g.
2239 Catamount. See L<perlport>.
2241 =item %sExecution of %s aborted due to compilation errors.
2243 (F) The final summary message when a Perl compilation fails.
2245 =item exists argument is not a HASH or ARRAY element or a subroutine
2247 (F) The argument to C<exists> must be a hash or array element or a
2248 subroutine with an ampersand, such as:
2254 =item exists argument is not a subroutine name
2256 (F) The argument to C<exists> for C<exists &sub> must be a subroutine name,
2257 and not a subroutine call. C<exists &sub()> will generate this error.
2259 =item Exiting eval via %s
2261 (W exiting) You are exiting an eval by unconventional means, such as a
2262 goto, or a loop control statement.
2264 =item Exiting format via %s
2266 (W exiting) You are exiting a format by unconventional means, such as a
2267 goto, or a loop control statement.
2269 =item Exiting pseudo-block via %s
2271 (W exiting) You are exiting a rather special block construct (like a
2272 sort block or subroutine) by unconventional means, such as a goto, or a
2273 loop control statement. See L<perlfunc/sort>.
2275 =item Exiting subroutine via %s
2277 (W exiting) You are exiting a subroutine by unconventional means, such
2278 as a goto, or a loop control statement.
2280 =item Exiting substitution via %s
2282 (W exiting) You are exiting a substitution by unconventional means, such
2283 as a return, a goto, or a loop control statement.
2285 =item Expecting close bracket in regex; marked by S<<-- HERE> in m/%s/
2287 (F) You wrote something like
2291 to denote a capturing group of the form
2292 L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>,
2293 but omitted the C<")">.
2295 =item Expecting interpolated extended charclass in regex; marked by <--
2298 (F) It looked like you were attempting to interpolate an
2299 already-compiled extended character class, like so:
2301 my $thai_or_lao = qr/(?[ \p{Thai} + \p{Lao} ])/;
2303 qr/(?[ \p{Digit} & $thai_or_lao ])/;
2305 But the marked code isn't syntactically correct to be such an
2308 =item Experimental aliasing via reference not enabled
2310 (F) To do aliasing via references, you must first enable the feature:
2312 no warnings "experimental::refaliasing";
2313 use feature "refaliasing";
2316 =item Experimental %s on scalar is now forbidden
2318 (F) An experimental feature added in Perl 5.14 allowed C<each>, C<keys>,
2319 C<push>, C<pop>, C<shift>, C<splice>, C<unshift>, and C<values> to be called with a
2320 scalar argument. This experiment is considered unsuccessful, and
2321 has been removed. The C<postderef> feature may meet your needs better.
2323 =item Experimental subroutine signatures not enabled
2325 (F) To use subroutine signatures, you must first enable them:
2327 no warnings "experimental::signatures";
2328 use feature "signatures";
2329 sub foo ($left, $right) { ... }
2331 =item Explicit blessing to '' (assuming package main)
2333 (W misc) You are blessing a reference to a zero length string. This has
2334 the effect of blessing the reference into the package main. This is
2335 usually not what you want. Consider providing a default target package,
2336 e.g. bless($ref, $p || 'MyPackage');
2338 =item %s: Expression syntax
2340 (A) You've accidentally run your script through B<csh> instead of Perl.
2341 Check the #! line, or manually feed your script into Perl yourself.
2343 =item %s failed--call queue aborted
2345 (F) An untrapped exception was raised while executing a UNITCHECK,
2346 CHECK, INIT, or END subroutine. Processing of the remainder of the
2347 queue of such routines has been prematurely ended.
2349 =item Failed to close in-place work file %s: %s
2351 (F) Closing an output file from in-place editing, as with the C<-i>
2352 command-line switch, failed.
2354 =item False [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
2356 (W regexp)(F) A character class range must start and end at a literal
2357 character, not another character class like C<\d> or C<[:alpha:]>. The "-"
2358 in your false range is interpreted as a literal "-". In a C<(?[...])>
2359 construct, this is an error, rather than a warning. Consider quoting
2360 the "-", "\-". The S<<-- HERE> shows whereabouts in the regular expression
2361 the problem was discovered. See L<perlre>.
2363 =item Fatal VMS error (status=%d) at %s, line %d
2365 (P) An error peculiar to VMS. Something untoward happened in a VMS
2366 system service or RTL routine; Perl's exit status should provide more
2367 details. The filename in "at %s" and the line number in "line %d" tell
2368 you which section of the Perl source code is distressed.
2370 =item fcntl is not implemented
2372 (F) Your machine apparently doesn't implement fcntl(). What is this, a
2373 PDP-11 or something?
2375 =item FETCHSIZE returned a negative value
2377 (F) A tied array claimed to have a negative number of elements, which
2380 =item Field too wide in 'u' format in pack
2382 (W pack) Each line in an uuencoded string starts with a length indicator
2383 which can't encode values above 63. So there is no point in asking for
2384 a line length bigger than that. Perl will behave as if you specified
2385 C<u63> as the format.
2387 =item File::Glob::glob() will disappear in perl 5.30. Use File::Glob::bsd_glob() instead.
2389 (D deprecated) C<< File::Glob >> has a function called C<< glob >>, which
2390 just calls C<< bsd_glob >>. However, its prototype is different from the
2391 prototype of C<< CORE::glob >>, and hence, C<< File::Glob::glob >> should
2394 C<< File::Glob::glob() >> was deprecated in perl 5.8.0. A deprecation
2395 message was issued from perl 5.26.0 onwards, and the function will
2396 disappear in perl 5.30.0.
2398 Code using C<< File::Glob::glob() >> should call
2399 C<< File::Glob::bsd_glob() >> instead.
2401 =item Filehandle %s opened only for input
2403 (W io) You tried to write on a read-only filehandle. If you intended
2404 it to be a read-write filehandle, you needed to open it with "+<" or
2405 "+>" or "+>>" instead of with "<" or nothing. If you intended only to
2406 write the file, use ">" or ">>". See L<perlfunc/open>.
2408 =item Filehandle %s opened only for output
2410 (W io) You tried to read from a filehandle opened only for writing, If
2411 you intended it to be a read/write filehandle, you needed to open it
2412 with "+<" or "+>" or "+>>" instead of with ">". If you intended only to
2413 read from the file, use "<". See L<perlfunc/open>. Another possibility
2414 is that you attempted to open filedescriptor 0 (also known as STDIN) for
2415 output (maybe you closed STDIN earlier?).
2417 =item Filehandle %s reopened as %s only for input
2419 (W io) You opened for reading a filehandle that got the same filehandle id
2420 as STDOUT or STDERR. This occurred because you closed STDOUT or STDERR
2423 =item Filehandle STDIN reopened as %s only for output
2425 (W io) You opened for writing a filehandle that got the same filehandle id
2426 as STDIN. This occurred because you closed STDIN previously.
2428 =item Final $ should be \$ or $name
2430 (F) You must now decide whether the final $ in a string was meant to be
2431 a literal dollar sign, or was meant to introduce a variable name that
2432 happens to be missing. So you have to put either the backslash or the
2435 =item flock() on closed filehandle %s
2437 (W closed) The filehandle you're attempting to flock() got itself closed
2438 some time before now. Check your control flow. flock() operates on
2439 filehandles. Are you attempting to call flock() on a dirhandle by the
2442 =item Format not terminated
2444 (F) A format must be terminated by a line with a solitary dot. Perl got
2445 to the end of your file without finding such a line.
2447 =item Format %s redefined
2449 (W redefine) You redefined a format. To suppress this warning, say
2452 no warnings 'redefine';
2453 eval "format NAME =...";
2456 =item Found = in conditional, should be ==
2466 (or something like that).
2468 =item %s found where operator expected
2470 (S syntax) The Perl lexer knows whether to expect a term or an operator.
2471 If it sees what it knows to be a term when it was expecting to see an
2472 operator, it gives you this warning. Usually it indicates that an
2473 operator or delimiter was omitted, such as a semicolon.
2475 =item gdbm store returned %d, errno %d, key "%s"
2477 (S) A warning from the GDBM_File extension that a store failed.
2479 =item gethostent not implemented
2481 (F) Your C library apparently doesn't implement gethostent(), probably
2482 because if it did, it'd feel morally obligated to return every hostname
2485 =item get%sname() on closed socket %s
2487 (W closed) You tried to get a socket or peer socket name on a closed
2488 socket. Did you forget to check the return value of your socket() call?
2490 =item getpwnam returned invalid UIC %#o for user "%s"
2492 (S) A warning peculiar to VMS. The call to C<sys$getuai> underlying the
2493 C<getpwnam> operator returned an invalid UIC.
2495 =item getsockopt() on closed socket %s
2497 (W closed) You tried to get a socket option on a closed socket. Did you
2498 forget to check the return value of your socket() call? See
2499 L<perlfunc/getsockopt>.
2501 =item given is experimental
2503 (S experimental::smartmatch) C<given> depends on smartmatch, which
2504 is experimental, so its behavior may change or even be removed
2505 in any future release of perl. See the explanation under
2506 L<perlsyn/Experimental Details on given and when>.
2508 =item Global symbol "%s" requires explicit package name (did you forget to
2511 (F) You've said "use strict" or "use strict vars", which indicates
2512 that all variables must either be lexically scoped (using "my" or "state"),
2513 declared beforehand using "our", or explicitly qualified to say
2514 which package the global variable is in (using "::").
2516 =item glob failed (%s)
2518 (S glob) Something went wrong with the external program(s) used
2519 for C<glob> and C<< <*.c> >>. Usually, this means that you supplied a C<glob>
2520 pattern that caused the external program to fail and exit with a
2521 nonzero status. If the message indicates that the abnormal exit
2522 resulted in a coredump, this may also mean that your csh (C shell)
2523 is broken. If so, you should change all of the csh-related variables
2524 in config.sh: If you have tcsh, make the variables refer to it as
2525 if it were csh (e.g. C<full_csh='/usr/bin/tcsh'>); otherwise, make them
2526 all empty (except that C<d_csh> should be C<'undef'>) so that Perl will
2527 think csh is missing. In either case, after editing config.sh, run
2528 C<./Configure -S> and rebuild Perl.
2530 =item Glob not terminated
2532 (F) The lexer saw a left angle bracket in a place where it was expecting
2533 a term, so it's looking for the corresponding right angle bracket, and
2534 not finding it. Chances are you left some needed parentheses out
2535 earlier in the line, and you really meant a "less than".
2537 =item gmtime(%f) failed
2539 (W overflow) You called C<gmtime> with a number that it could not handle:
2540 too large, too small, or NaN. The returned value is C<undef>.
2542 =item gmtime(%f) too large
2544 (W overflow) You called C<gmtime> with a number that was larger than
2545 it can reliably handle and C<gmtime> probably returned the wrong
2546 date. This warning is also triggered with NaN (the special
2547 not-a-number value).
2549 =item gmtime(%f) too small
2551 (W overflow) You called C<gmtime> with a number that was smaller than
2552 it can reliably handle and C<gmtime> probably returned the wrong date.
2554 =item Got an error from DosAllocMem
2556 (P) An error peculiar to OS/2. Most probably you're using an obsolete
2557 version of Perl, and this should not happen anyway.
2559 =item goto must have label
2561 (F) Unlike with "next" or "last", you're not allowed to goto an
2562 unspecified destination. See L<perlfunc/goto>.
2564 =item Goto undefined subroutine%s
2566 (F) You tried to call a subroutine with C<goto &sub> syntax, but
2567 the indicated subroutine hasn't been defined, or if it was, it
2568 has since been undefined.
2570 =item Group name must start with a non-digit word character in regex; marked by
2571 S<<-- HERE> in m/%s/
2573 (F) Group names must follow the rules for perl identifiers, meaning
2574 they must start with a non-digit word character. A common cause of
2575 this error is using (?&0) instead of (?0). See L<perlre>.
2577 =item ()-group starts with a count
2579 (F) A ()-group started with a count. A count is supposed to follow
2580 something: a template character or a ()-group. See L<perlfunc/pack>.
2582 =item %s had compilation errors.
2584 (F) The final summary message when a C<perl -c> fails.
2586 =item Had to create %s unexpectedly
2588 (S internal) A routine asked for a symbol from a symbol table that ought
2589 to have existed already, but for some reason it didn't, and had to be
2590 created on an emergency basis to prevent a core dump.
2592 =item %s has too many errors
2594 (F) The parser has given up trying to parse the program after 10 errors.
2595 Further error messages would likely be uninformative.
2597 =item Hexadecimal float: exponent overflow
2599 (W overflow) The hexadecimal floating point has a larger exponent
2600 than the floating point supports.
2602 =item Hexadecimal float: exponent underflow
2604 (W overflow) The hexadecimal floating point has a smaller exponent
2605 than the floating point supports. With the IEEE 754 floating point,
2606 this may also mean that the subnormals (formerly known as denormals)
2607 are being used, which may or may not be an error.
2609 =item Hexadecimal float: internal error (%s)
2611 (F) Something went horribly bad in hexadecimal float handling.
2613 =item Hexadecimal float: mantissa overflow
2615 (W overflow) The hexadecimal floating point literal had more bits in
2616 the mantissa (the part between the 0x and the exponent, also known as
2617 the fraction or the significand) than the floating point supports.
2619 =item Hexadecimal float: precision loss
2621 (W overflow) The hexadecimal floating point had internally more
2622 digits than could be output. This can be caused by unsupported
2623 long double formats, or by 64-bit integers not being available
2624 (needed to retrieve the digits under some configurations).
2626 =item Hexadecimal float: unsupported long double format
2628 (F) You have configured Perl to use long doubles but
2629 the internals of the long double format are unknown;
2630 therefore the hexadecimal float output is impossible.
2632 =item Hexadecimal number > 0xffffffff non-portable
2634 (W portable) The hexadecimal number you specified is larger than 2**32-1
2635 (4294967295) and therefore non-portable between systems. See
2636 L<perlport> for more on portability concerns.
2638 =item Identifier too long
2640 (F) Perl limits identifiers (names for variables, functions, etc.) to
2641 about 250 characters for simple names, and somewhat more for compound
2642 names (like C<$A::B>). You've exceeded Perl's limits. Future versions
2643 of Perl are likely to eliminate these arbitrary limitations.
2645 =item Ignoring zero length \N{} in character class in regex; marked by
2646 S<<-- HERE> in m/%s/
2648 (W regexp) Named Unicode character escapes (C<\N{...}>) may return a
2649 zero-length sequence. When such an escape is used in a character
2650 class its behavior is not well defined. Check that the correct
2651 escape has been used, and the correct charname handler is in scope.
2653 =item Illegal %s digit '%c' ignored
2655 (W digit) Here C<%s> is one of "binary", "octal", or "hex".
2656 You may have tried to use a digit other than one that is legal for the
2657 given type, such as only 0 and 1 for binary. For octals, this is raised
2658 only if the illegal character is an '8' or '9'. For hex, 'A' - 'F' and
2659 'a' - 'f' are legal.
2660 Interpretation of the number stopped just before the offending digit or
2663 =item Illegal binary digit '%c'
2665 (F) You used a digit other than 0 or 1 in a binary number.
2667 =item Illegal character after '_' in prototype for %s : %s
2669 (W illegalproto) An illegal character was found in a prototype
2670 declaration. The '_' in a prototype must be followed by a ';',
2671 indicating the rest of the parameters are optional, or one of '@'
2672 or '%', since those two will accept 0 or more final parameters.
2674 =item Illegal character \%o (carriage return)
2676 (F) Perl normally treats carriage returns in the program text as
2677 it would any other whitespace, which means you should never see
2678 this error when Perl was built using standard options. For some
2679 reason, your version of Perl appears to have been built without
2680 this support. Talk to your Perl administrator.
2682 =item Illegal character following sigil in a subroutine signature
2684 (F) A parameter in a subroutine signature contained an unexpected character
2685 following the C<$>, C<@> or C<%> sigil character. Normally the sigil
2686 should be followed by the variable name or C<=> etc. Perhaps you are
2687 trying use a prototype while in the scope of C<use feature 'signatures'>?
2690 sub foo ($$) {} # legal - a prototype
2692 use feature 'signatures;
2693 sub foo ($$) {} # illegal - was expecting a signature
2695 :prototype($$) {} # legal
2698 =item Illegal character in prototype for %s : %s
2700 (W illegalproto) An illegal character was found in a prototype declaration.
2701 Legal characters in prototypes are $, @, %, *, ;, [, ], &, \, and +.
2702 Perhaps you were trying to write a subroutine signature but didn't enable
2703 that feature first (C<use feature 'signatures'>), so your signature was
2704 instead interpreted as a bad prototype.
2706 =item Illegal declaration of anonymous subroutine
2708 (F) When using the C<sub> keyword to construct an anonymous subroutine,
2709 you must always specify a block of code. See L<perlsub>.
2711 =item Illegal declaration of subroutine %s
2713 (F) A subroutine was not declared correctly. See L<perlsub>.
2715 =item Illegal division by zero
2717 (F) You tried to divide a number by 0. Either something was wrong in
2718 your logic, or you need to put a conditional in to guard against
2721 =item Illegal modulus zero
2723 (F) You tried to divide a number by 0 to get the remainder. Most
2724 numbers don't take to this kindly.
2726 =item Illegal number of bits in vec
2728 (F) The number of bits in vec() (the third argument) must be a power of
2729 two from 1 to 32 (or 64, if your platform supports that).
2731 =item Illegal octal digit '%c'
2733 (F) You used an 8 or 9 in an octal number.
2735 =item Illegal operator following parameter in a subroutine signature
2737 (F) A parameter in a subroutine signature, was followed by something
2738 other than C<=> introducing a default, C<,> or C<)>.
2740 use feature 'signatures';
2741 sub foo ($=1) {} # legal
2742 sub foo ($a = 1) {} # legal
2743 sub foo ($a += 1) {} # illegal
2744 sub foo ($a == 1) {} # illegal
2746 =item Illegal pattern in regex; marked by S<<-- HERE> in m/%s/
2748 (F) You wrote something like
2752 The C<"+"> is valid only when followed by digits, indicating a
2753 capturing group. See
2754 L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>.
2756 =item Illegal suidscript
2758 (F) The script run under suidperl was somehow illegal.
2760 =item Illegal switch in PERL5OPT: -%c
2762 (X) The PERL5OPT environment variable may only be used to set the
2763 following switches: B<-[CDIMUdmtw]>.
2765 =item Illegal user-defined property name
2767 (F) You specified a Unicode-like property name in a regular expression
2768 pattern (using C<\p{}> or C<\P{}>) that Perl knows isn't an official
2769 Unicode property, and was likely meant to be a user-defined property
2770 name, but it can't be one of those, as they must begin with either C<In>
2771 or C<Is>. Check the spelling. See also
2772 L</Can't find Unicode property definition "%s">.
2774 =item Ill-formed CRTL environ value "%s"
2776 (W internal) A warning peculiar to VMS. Perl tried to read the CRTL's
2777 internal environ array, and encountered an element without the C<=>
2778 delimiter used to separate keys from values. The element is ignored.
2780 =item Ill-formed message in prime_env_iter: |%s|
2782 (W internal) A warning peculiar to VMS. Perl tried to read a logical
2783 name or CLI symbol definition when preparing to iterate over %ENV, and
2784 didn't see the expected delimiter between key and value, so the line was
2787 =item (in cleanup) %s
2789 (W misc) This prefix usually indicates that a DESTROY() method raised
2790 the indicated exception. Since destructors are usually called by the
2791 system at arbitrary points during execution, and often a vast number of
2792 times, the warning is issued only once for any number of failures that
2793 would otherwise result in the same message being repeated.
2795 Failure of user callbacks dispatched using the C<G_KEEPERR> flag could
2796 also result in this warning. See L<perlcall/G_KEEPERR>.
2798 =item Incomplete expression within '(?[ ])' in regex; marked by S<<-- HERE>
2801 (F) There was a syntax error within the C<(?[ ])>. This can happen if the
2802 expression inside the construct was completely empty, or if there are
2803 too many or few operands for the number of operators. Perl is not smart
2804 enough to give you a more precise indication as to what is wrong.
2806 =item Inconsistent hierarchy during C3 merge of class '%s': merging failed on
2809 (F) The method resolution order (MRO) of the given class is not
2810 C3-consistent, and you have enabled the C3 MRO for this class. See the C3
2811 documentation in L<mro> for more information.
2813 =item Indentation on line %d of here-doc doesn't match delimiter
2815 (F) You have an indented here-document where one or more of its lines
2816 have whitespace at the beginning that does not match the closing
2819 For example, line 2 below is wrong because it does not have at least
2820 2 spaces, but lines 1 and 3 are fine because they have at least 2:
2830 Note that tabs and spaces are compared strictly, meaning 1 tab will
2833 =item Infinite recursion in regex
2835 (F) You used a pattern that references itself without consuming any input
2836 text. You should check the pattern to ensure that recursive patterns
2837 either consume text or fail.
2839 =item Infinite recursion via empty pattern
2841 (F) You tried to use the empty pattern inside of a regex code block,
2842 for instance C</(?{ s!!! })/>, which resulted in re-executing
2843 the same pattern, which is an infinite loop which is broken by
2844 throwing an exception.
2846 =item Initialization of state variables in list currently forbidden
2848 (F) C<state> only permits initializing a single variable, specified
2849 without parentheses. So C<state $a = 42> and C<state @a = qw(a b c)> are
2850 allowed, but not C<state ($a) = 42> or C<(state $a) = 42>. To initialize
2851 more than one C<state> variable, initialize them one at a time.
2853 =item %%s[%s] in scalar context better written as $%s[%s]
2855 (W syntax) In scalar context, you've used an array index/value slice
2856 (indicated by %) to select a single element of an array. Generally
2857 it's better to ask for a scalar value (indicated by $). The difference
2858 is that C<$foo[&bar]> always behaves like a scalar, both in the value it
2859 returns and when evaluating its argument, while C<%foo[&bar]> provides
2860 a list context to its subscript, which can do weird things if you're
2861 expecting only one subscript. When called in list context, it also
2862 returns the index (what C<&bar> returns) in addition to the value.
2864 =item %%s{%s} in scalar context better written as $%s{%s}
2866 (W syntax) In scalar context, you've used a hash key/value slice
2867 (indicated by %) to select a single element of a hash. Generally it's
2868 better to ask for a scalar value (indicated by $). The difference
2869 is that C<$foo{&bar}> always behaves like a scalar, both in the value
2870 it returns and when evaluating its argument, while C<@foo{&bar}> and
2871 provides a list context to its subscript, which can do weird things
2872 if you're expecting only one subscript. When called in list context,
2873 it also returns the key in addition to the value.
2875 =item Insecure dependency in %s
2877 (F) You tried to do something that the tainting mechanism didn't like.
2878 The tainting mechanism is turned on when you're running setuid or
2879 setgid, or when you specify B<-T> to turn it on explicitly. The
2880 tainting mechanism labels all data that's derived directly or indirectly
2881 from the user, who is considered to be unworthy of your trust. If any
2882 such data is used in a "dangerous" operation, you get this error. See
2883 L<perlsec> for more information.
2885 =item Insecure directory in %s
2887 (F) You can't use system(), exec(), or a piped open in a setuid or
2888 setgid script if C<$ENV{PATH}> contains a directory that is writable by
2889 the world. Also, the PATH must not contain any relative directory.
2892 =item Insecure $ENV{%s} while running %s
2894 (F) You can't use system(), exec(), or a piped open in a setuid or
2895 setgid script if any of C<$ENV{PATH}>, C<$ENV{IFS}>, C<$ENV{CDPATH}>,
2896 C<$ENV{ENV}>, C<$ENV{BASH_ENV}> or C<$ENV{TERM}> are derived from data
2897 supplied (or potentially supplied) by the user. The script must set
2898 the path to a known value, using trustworthy data. See L<perlsec>.
2900 =item Insecure user-defined property %s
2902 (F) Perl detected tainted data when trying to compile a regular
2903 expression that contains a call to a user-defined character property
2904 function, i.e. C<\p{IsFoo}> or C<\p{InFoo}>.
2905 See L<perlunicode/User-Defined Character Properties> and L<perlsec>.
2907 =item Integer overflow in format string for %s
2909 (F) The indexes and widths specified in the format string of C<printf()>
2910 or C<sprintf()> are too large. The numbers must not overflow the size of
2911 integers for your architecture.
2913 =item Integer overflow in %s number
2915 (S overflow) The hexadecimal, octal or binary number you have specified
2916 either as a literal or as an argument to hex() or oct() is too big for
2917 your architecture, and has been converted to a floating point number.
2918 On a 32-bit architecture the largest hexadecimal, octal or binary number
2919 representable without overflow is 0xFFFFFFFF, 037777777777, or
2920 0b11111111111111111111111111111111 respectively. Note that Perl
2921 transparently promotes all numbers to a floating point representation
2922 internally--subject to loss of precision errors in subsequent
2925 =item Integer overflow in srand
2927 (S overflow) The number you have passed to srand is too big to fit
2928 in your architecture's integer representation. The number has been
2929 replaced with the largest integer supported (0xFFFFFFFF on 32-bit
2930 architectures). This means you may be getting less randomness than
2931 you expect, because different random seeds above the maximum will
2932 return the same sequence of random numbers.
2934 =item Integer overflow in version
2936 =item Integer overflow in version %d
2938 (W overflow) Some portion of a version initialization is too large for
2939 the size of integers for your architecture. This is not a warning
2940 because there is no rational reason for a version to try and use an
2941 element larger than typically 2**32. This is usually caused by trying
2942 to use some odd mathematical operation as a version, like 100/9.
2944 =item Internal disaster in regex; marked by S<<-- HERE> in m/%s/
2946 (P) Something went badly wrong in the regular expression parser.
2947 The S<<-- HERE> shows whereabouts in the regular expression the problem was
2950 =item Internal inconsistency in tracking vforks
2952 (S) A warning peculiar to VMS. Perl keeps track of the number of times
2953 you've called C<fork> and C<exec>, to determine whether the current call
2954 to C<exec> should affect the current script or a subprocess (see
2955 L<perlvms/"exec LIST">). Somehow, this count has become scrambled, so
2956 Perl is making a guess and treating this C<exec> as a request to
2957 terminate the Perl script and execute the specified command.
2959 =item internal %<num>p might conflict with future printf extensions
2961 (S internal) Perl's internal routine that handles C<printf> and C<sprintf>
2962 formatting follows a slightly different set of rules when called from
2963 C or XS code. Specifically, formats consisting of digits followed
2964 by "p" (e.g., "%7p") are reserved for future use. If you see this
2965 message, then an XS module tried to call that routine with one such
2968 =item Internal urp in regex; marked by S<<-- HERE> in m/%s/
2970 (P) Something went badly awry in the regular expression parser. The
2971 S<<-- HERE> shows whereabouts in the regular expression the problem was
2974 =item %s (...) interpreted as function
2976 (W syntax) You've run afoul of the rule that says that any list operator
2977 followed by parentheses turns into a function, with all the list
2978 operators arguments found inside the parentheses. See
2979 L<perlop/Terms and List Operators (Leftward)>.
2981 =item In '(?...)', the '(' and '?' must be adjacent in regex;
2982 marked by S<<-- HERE> in m/%s/
2984 (F) The two-character sequence C<"(?"> in this context in a regular
2985 expression pattern should be an indivisible token, with nothing
2986 intervening between the C<"("> and the C<"?">, but you separated them
2989 =item In '(*...)', the '(' and '*' must be adjacent in regex;
2990 marked by S<<-- HERE> in m/%s/
2992 (F) The two-character sequence C<"(*"> in this context in a regular
2993 expression pattern should be an indivisible token, with nothing
2994 intervening between the C<"("> and the C<"*">, but you separated them.
2995 Fix the pattern and retry.
2997 =item Invalid %s attribute: %s
2999 (F) The indicated attribute for a subroutine or variable was not recognized
3000 by Perl or by a user-supplied handler. See L<attributes>.
3002 =item Invalid %s attributes: %s
3004 (F) The indicated attributes for a subroutine or variable were not
3005 recognized by Perl or by a user-supplied handler. See L<attributes>.
3007 =item Invalid character in charnames alias definition; marked by
3010 (F) You tried to create a custom alias for a character name, with
3011 the C<:alias> option to C<use charnames> and the specified character in
3012 the indicated name isn't valid. See L<charnames/CUSTOM ALIASES>.
3014 =item Invalid \0 character in %s for %s: %s\0%s
3016 (W syscalls) Embedded \0 characters in pathnames or other system call
3017 arguments produce a warning as of 5.20. The parts after the \0 were
3018 formerly ignored by system calls.
3020 =item Invalid character in \N{...}; marked by S<<-- HERE> in \N{%s}
3022 (F) Only certain characters are valid for character names. The
3023 indicated one isn't. See L<charnames/CUSTOM ALIASES>.
3025 =item Invalid conversion in %s: "%s"
3027 (W printf) Perl does not understand the given format conversion. See
3028 L<perlfunc/sprintf>.
3030 =item Invalid escape in the specified encoding in regex; marked by
3031 S<<-- HERE> in m/%s/
3033 (W regexp)(F) The numeric escape (for example C<\xHH>) of value < 256
3034 didn't correspond to a single character through the conversion
3035 from the encoding specified by the encoding pragma.
3036 The escape was replaced with REPLACEMENT CHARACTER (U+FFFD)
3037 instead, except within S<C<(?[ ])>>, where it is a fatal error.
3038 The S<<-- HERE> shows whereabouts in the regular expression the
3039 escape was discovered.
3041 =item Invalid hexadecimal number in \N{U+...}
3043 =item Invalid hexadecimal number in \N{U+...} in regex; marked by
3044 S<<-- HERE> in m/%s/
3046 (F) The character constant represented by C<...> is not a valid hexadecimal
3047 number. Either it is empty, or you tried to use a character other than
3048 0 - 9 or A - F, a - f in a hexadecimal number.
3050 =item Invalid module name %s with -%c option: contains single ':'
3052 (F) The module argument to perl's B<-m> and B<-M> command-line options
3053 cannot contain single colons in the module name, but only in the
3054 arguments after "=". In other words, B<-MFoo::Bar=:baz> is ok, but
3055 B<-MFoo:Bar=baz> is not.
3057 =item Invalid mro name: '%s'
3059 (F) You tried to C<mro::set_mro("classname", "foo")> or C<use mro 'foo'>,
3060 where C<foo> is not a valid method resolution order (MRO). Currently,
3061 the only valid ones supported are C<dfs> and C<c3>, unless you have loaded
3062 a module that is a MRO plugin. See L<mro> and L<perlmroapi>.
3064 =item Invalid negative number (%s) in chr
3066 (W utf8) You passed a negative number to C<chr>. Negative numbers are
3067 not valid character numbers, so it returns the Unicode replacement
3070 =item Invalid number '%s' for -C option.
3072 (F) You supplied a number to the -C option that either has extra leading
3073 zeroes or overflows perl's unsigned integer representation.
3075 =item invalid option -D%c, use -D'' to see choices
3077 (S debugging) Perl was called with invalid debugger flags. Call perl
3078 with the B<-D> option with no flags to see the list of acceptable values.
3079 See also L<perlrun/-Dletters>.
3081 =item Invalid quantifier in {,} in regex; marked by S<<-- HERE> in m/%s/
3083 (F) The pattern looks like a {min,max} quantifier, but the min or max
3084 could not be parsed as a valid number - either it has leading zeroes,
3085 or it represents too big a number to cope with. The S<<-- HERE> shows
3086 where in the regular expression the problem was discovered. See L<perlre>.
3088 =item Invalid [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
3090 (F) The range specified in a character class had a minimum character
3091 greater than the maximum character. One possibility is that you forgot the
3092 C<{}> from your ending C<\x{}> - C<\x> without the curly braces can go only
3093 up to C<ff>. The S<<-- HERE> shows whereabouts in the regular expression the
3094 problem was discovered. See L<perlre>.
3096 =item Invalid range "%s" in transliteration operator
3098 (F) The range specified in the tr/// or y/// operator had a minimum
3099 character greater than the maximum character. See L<perlop>.
3101 =item Invalid reference to group in regex; marked by S<<-- HERE> in m/%s/
3103 (F) The capture group you specified can't possibly exist because the
3104 number you used is not within the legal range of possible values for
3107 =item Invalid separator character %s in attribute list
3109 (F) Something other than a colon or whitespace was seen between the
3110 elements of an attribute list. If the previous attribute had a
3111 parenthesised parameter list, perhaps that list was terminated too soon.
3114 =item Invalid separator character %s in PerlIO layer specification %s
3116 (W layer) When pushing layers onto the Perl I/O system, something other
3117 than a colon or whitespace was seen between the elements of a layer list.
3118 If the previous attribute had a parenthesised parameter list, perhaps that
3119 list was terminated too soon.
3121 =item Invalid strict version format (%s)
3123 (F) A version number did not meet the "strict" criteria for versions.
3124 A "strict" version number is a positive decimal number (integer or
3125 decimal-fraction) without exponentiation or else a dotted-decimal
3126 v-string with a leading 'v' character and at least three components.
3127 The parenthesized text indicates which criteria were not met.
3128 See the L<version> module for more details on allowed version formats.
3130 =item Invalid type '%s' in %s
3132 (F) The given character is not a valid pack or unpack type.
3133 See L<perlfunc/pack>.
3135 (W) The given character is not a valid pack or unpack type but used to be
3138 =item Invalid version format (%s)
3140 (F) A version number did not meet the "lax" criteria for versions.
3141 A "lax" version number is a positive decimal number (integer or
3142 decimal-fraction) without exponentiation or else a dotted-decimal
3143 v-string. If the v-string has fewer than three components, it
3144 must have a leading 'v' character. Otherwise, the leading 'v' is
3145 optional. Both decimal and dotted-decimal versions may have a
3146 trailing "alpha" component separated by an underscore character
3147 after a fractional or dotted-decimal component. The parenthesized
3148 text indicates which criteria were not met. See the L<version> module
3149 for more details on allowed version formats.
3151 =item Invalid version object
3153 (F) The internal structure of the version object was invalid.
3154 Perhaps the internals were modified directly in some way or
3155 an arbitrary reference was blessed into the "version" class.
3157 =item In '(*VERB...)', the '(' and '*' must be adjacent in regex;
3158 marked by S<<-- HERE> in m/%s/
3160 =item Inverting a character class which contains a multi-character
3161 sequence is illegal in regex; marked by <-- HERE in m/%s/
3163 (F) You wrote something like
3165 qr/\P{name=KATAKANA LETTER AINU P}/
3166 qr/[^\p{name=KATAKANA LETTER AINU P}]/
3168 This name actually evaluates to a sequence of two Katakana characters,
3169 not just a single one, and it is illegal to try to take the complement
3170 of a sequence. (Mathematically it would mean any sequence of characters
3171 from 0 to infinity in length that weren't these two in a row, and that
3172 is likely not of any real use.)
3174 (F) The two-character sequence C<"(*"> in this context in a regular
3175 expression pattern should be an indivisible token, with nothing
3176 intervening between the C<"("> and the C<"*">, but you separated them.
3178 =item ioctl is not implemented
3180 (F) Your machine apparently doesn't implement ioctl(), which is pretty
3181 strange for a machine that supports C.
3183 =item ioctl() on unopened %s
3185 (W unopened) You tried ioctl() on a filehandle that was never opened.
3186 Check your control flow and number of arguments.
3188 =item IO layers (like '%s') unavailable
3190 (F) Your Perl has not been configured to have PerlIO, and therefore
3191 you cannot use IO layers. To have PerlIO, Perl must be configured
3194 =item IO::Socket::atmark not implemented on this architecture
3196 (F) Your machine doesn't implement the sockatmark() functionality,
3197 neither as a system call nor an ioctl call (SIOCATMARK).
3199 =item '%s' is an unknown bound type in regex; marked by S<<-- HERE> in m/%s/
3201 (F) You used C<\b{...}> or C<\B{...}> and the C<...> is not known to
3202 Perl. The current valid ones are given in
3203 L<perlrebackslash/\b{}, \b, \B{}, \B>.
3205 =item %s is forbidden - matches null string many times in regex; marked by S<<-- HERE> in
3208 (F) The pattern you've specified might cause the regular expression to
3209 infinite loop so it is forbidden. The S<<-- HERE>
3210 shows whereabouts in the regular expression the problem was discovered.
3213 =item %s() isn't allowed on :utf8 handles
3215 (F) The sysread(), recv(), syswrite() and send() operators are
3216 not allowed on handles that have the C<:utf8> layer, either explicitly, or
3217 implicitly, eg., with the C<:encoding(UTF-16LE)> layer.
3219 Previously sysread() and recv() currently use only the C<:utf8> flag for the stream,
3220 ignoring the actual layers. Since sysread() and recv() did no UTF-8
3221 validation they can end up creating invalidly encoded scalars.
3223 Similarly, syswrite() and send() used only the C<:utf8> flag, otherwise ignoring
3224 any layers. If the flag is set, both wrote the value UTF-8 encoded, even if
3225 the layer is some different encoding, such as the example above.
3227 Ideally, all of these operators would completely ignore the C<:utf8> state,
3228 working only with bytes, but this would result in silently breaking existing
3231 =item "%s" is more clearly written simply as "%s" in regex; marked by S<<-- HERE> in m/%s/
3233 (W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
3235 You specified a character that has the given plainer way of writing it, and
3236 which is also portable to platforms running with different character sets.
3238 =item $* is no longer supported as of Perl 5.30
3240 (F) The special variable C<$*>, deprecated in older perls, was removed in
3241 5.10.0, is no longer supported and is a fatal error as of Perl 5.30. In
3242 previous versions of perl the use of C<$*> enabled or disabled multi-line
3243 matching within a string.
3245 Instead of using C<$*> you should use the C</m> (and maybe C</s>) regexp
3246 modifiers. You can enable C</m> for a lexical scope (even a whole file)
3247 with C<use re '/m'>. (In older versions: when C<$*> was set to a true value
3248 then all regular expressions behaved as if they were written using C</m>.)
3250 Use of this variable will be a fatal error in Perl 5.30.
3252 =item $# is no longer supported as of Perl 5.30
3254 (F) The special variable C<$#>, deprecated in older perls, was removed as of
3255 5.10.0, is no longer supported and is a fatal error as of Perl 5.30. You
3256 should use the printf/sprintf functions instead.
3258 =item '%s' is not a code reference
3260 (W overload) The second (fourth, sixth, ...) argument of
3261 overload::constant needs to be a code reference. Either
3262 an anonymous subroutine, or a reference to a subroutine.
3264 =item '%s' is not an overloadable type
3266 (W overload) You tried to overload a constant type the overload package is
3269 =item isa is experimental
3271 (S experimental::isa) This warning is emitted if you use the (C<isa>)
3272 operator. This operator is currently experimental and its behaviour may
3273 change in future releases of Perl.
3275 =item -i used with no filenames on the command line, reading from STDIN
3277 (S inplace) The C<-i> option was passed on the command line, indicating
3278 that the script is intended to edit files in place, but no files were
3279 given. This is usually a mistake, since editing STDIN in place doesn't
3280 make sense, and can be confusing because it can make perl look like
3281 it is hanging when it is really just trying to read from STDIN. You
3282 should either pass a filename to edit, or remove C<-i> from the command
3283 line. See L<perlrun|perlrun/-i[extension]> for more details.
3285 =item Junk on end of regexp in regex m/%s/
3287 (P) The regular expression parser is confused.
3289 =item \K not permitted in lookahead/lookbehind in regex; marked by <-- HERE in m/%s/
3291 (F) Your regular expression used C<\K> in a lookhead or lookbehind
3292 assertion, which currently isn't permitted.
3294 This may change in the future, see L<Support \K in
3295 lookarounds|https://github.com/Perl/perl5/issues/18134>.
3297 =item Label not found for "last %s"
3299 (F) You named a loop to break out of, but you're not currently in a loop
3300 of that name, not even if you count where you were called from. See
3303 =item Label not found for "next %s"
3305 (F) You named a loop to continue, but you're not currently in a loop of
3306 that name, not even if you count where you were called from. See
3309 =item Label not found for "redo %s"
3311 (F) You named a loop to restart, but you're not currently in a loop of
3312 that name, not even if you count where you were called from. See
3315 =item leaving effective %s failed
3317 (F) While under the C<use filetest> pragma, switching the real and
3318 effective uids or gids failed.
3320 =item length/code after end of string in unpack
3322 (F) While unpacking, the string buffer was already used up when an unpack
3323 length/code combination tried to obtain more data. This results in
3324 an undefined value for the length. See L<perlfunc/pack>.
3326 =item length() used on %s (did you mean "scalar(%s)"?)
3328 (W syntax) You used length() on either an array or a hash when you
3329 probably wanted a count of the items.
3331 Array size can be obtained by doing:
3335 The number of items in a hash can be obtained by doing:
3339 =item Lexing code attempted to stuff non-Latin-1 character into Latin-1 input
3341 (F) An extension is attempting to insert text into the current parse
3342 (using L<lex_stuff_pvn|perlapi/lex_stuff_pvn> or similar), but tried to insert a character that
3343 couldn't be part of the current input. This is an inherent pitfall
3344 of the stuffing mechanism, and one of the reasons to avoid it. Where
3345 it is necessary to stuff, stuffing only plain ASCII is recommended.
3347 =item Lexing code internal error (%s)
3349 (F) Lexing code supplied by an extension violated the lexer's API in a
3352 =item listen() on closed socket %s
3354 (W closed) You tried to do a listen on a closed socket. Did you forget
3355 to check the return value of your socket() call? See
3358 =item List form of piped open not implemented
3360 (F) On some platforms, notably Windows, the three-or-more-arguments
3361 form of C<open> does not support pipes, such as C<open($pipe, '|-', @args)>.
3362 Use the two-argument C<open($pipe, '|prog arg1 arg2...')> form instead.
3364 =item Literal vertical space in [] is illegal except under /x in regex;
3365 marked by S<<-- HERE> in m/%s/
3367 (F) (only under C<S<use re 'strict'>> or within C<(?[...])>)
3369 Likely you forgot the C</x> modifier or there was a typo in the pattern.
3370 For example, did you really mean to match a form-feed? If so, all the
3371 ASCII vertical space control characters are representable by escape
3372 sequences which won't present such a jarring appearance as your pattern
3373 does when displayed.
3380 =item %s: loadable library and perl binaries are mismatched (got handshake key %p, needed %p)
3382 (P) A dynamic loading library C<.so> or C<.dll> was being loaded into the
3383 process that was built against a different build of perl than the
3384 said library was compiled against. Reinstalling the XS module will
3385 likely fix this error.
3387 =item Locale '%s' contains (at least) the following characters which
3388 have unexpected meanings: %s The Perl program will use the expected
3391 (W locale) You are using the named UTF-8 locale. UTF-8 locales are
3392 expected to have very particular behavior, which most do. This message
3393 arises when perl found some departures from the expectations, and is
3394 notifying you that the expected behavior overrides these differences.
3395 In some cases the differences are caused by the locale definition being
3396 defective, but the most common causes of this warning are when there are
3397 ambiguities and conflicts in following the Standard, and the locale has
3398 chosen an approach that differs from Perl's.
3400 One of these is because that, contrary to the claims, Unicode is not
3401 completely locale insensitive. Turkish and some related languages
3402 have two types of C<"I"> characters. One is dotted in both upper- and
3403 lowercase, and the other is dotless in both cases. Unicode allows a
3404 locale to use either the Turkish rules, or the rules used in all other
3405 instances, where there is only one type of C<"I">, which is dotless in
3406 the uppercase, and dotted in the lower. The perl core does not (yet)
3407 handle the Turkish case, and this message warns you of that. Instead,
3408 the L<Unicode::Casing> module allows you to mostly implement the Turkish
3411 The other common cause is for the characters
3415 These are problematic. The C standard says that these should be
3416 considered punctuation in the C locale (and the POSIX standard defers to
3417 the C standard), and Unicode is generally considered a superset of
3418 the C locale. But Unicode has added an extra category, "Symbol", and
3419 classifies these particular characters as being symbols. Most UTF-8
3420 locales have them treated as punctuation, so that L<ispunct(2)> returns
3421 non-zero for them. But a few locales have it return 0. Perl takes
3422 the first approach, not using C<ispunct()> at all (see L<Note [5] in
3423 perlrecharclass|perlrecharclass/[5]>), and this message is raised to notify you that you
3424 are getting Perl's approach, not the locale's.
3426 =item Locale '%s' may not work well.%s
3428 (W locale) You are using the named locale, which is a non-UTF-8 one, and
3429 which perl has determined is not fully compatible with what it can
3430 handle. The second C<%s> gives a reason.
3432 By far the most common reason is that the locale has characters in it
3433 that are represented by more than one byte. The only such locales that
3434 Perl can handle are the UTF-8 locales. Most likely the specified locale
3435 is a non-UTF-8 one for an East Asian language such as Chinese or
3436 Japanese. If the locale is a superset of ASCII, the ASCII portion of it
3439 Some essentially obsolete locales that aren't supersets of ASCII, mainly
3440 those in ISO 646 or other 7-bit locales, such as ASMO 449, can also have
3441 problems, depending on what portions of the ASCII character set get
3442 changed by the locale and are also used by the program.
3443 The warning message lists the determinable conflicting characters.
3445 Note that not all incompatibilities are found.
3447 If this happens to you, there's not much you can do except switch to use a
3448 different locale or use L<Encode> to translate from the locale into
3449 UTF-8; if that's impracticable, you have been warned that some things
3452 This message is output once each time a bad locale is switched into
3453 within the scope of C<S<use locale>>, or on the first possibly-affected
3454 operation if the C<S<use locale>> inherits a bad one. It is not raised
3455 for any operations from the L<POSIX> module.
3457 =item localtime(%f) failed
3459 (W overflow) You called C<localtime> with a number that it could not handle:
3460 too large, too small, or NaN. The returned value is C<undef>.
3462 =item localtime(%f) too large
3464 (W overflow) You called C<localtime> with a number that was larger
3465 than it can reliably handle and C<localtime> probably returned the
3466 wrong date. This warning is also triggered with NaN (the special
3467 not-a-number value).
3469 =item localtime(%f) too small
3471 (W overflow) You called C<localtime> with a number that was smaller
3472 than it can reliably handle and C<localtime> probably returned the
3475 =item Lookbehind longer than %d not implemented in regex m/%s/
3477 (F) There is currently a limit on the length of string which lookbehind can
3478 handle. This restriction may be eased in a future release.
3480 =item Lost precision when %s %f by 1
3482 (W imprecision) The value you attempted to increment or decrement by one
3483 is too large for the underlying floating point representation to store
3484 accurately, hence the target of C<++> or C<--> is unchanged. Perl issues this
3485 warning because it has already switched from integers to floating point
3486 when values are too large for integers, and now even floating point is
3487 insufficient. You may wish to switch to using L<Math::BigInt> explicitly.
3489 =item lstat() on filehandle%s
3491 (W io) You tried to do an lstat on a filehandle. What did you mean
3492 by that? lstat() makes sense only on filenames. (Perl did a fstat()
3493 instead on the filehandle.)
3495 =item lvalue attribute %s already-defined subroutine
3497 (W misc) Although L<attributes.pm|attributes> allows this, turning the lvalue
3498 attribute on or off on a Perl subroutine that is already defined
3499 does not always work properly. It may or may not do what you
3500 want, depending on what code is inside the subroutine, with exact
3501 details subject to change between Perl versions. Only do this
3502 if you really know what you are doing.
3504 =item lvalue attribute ignored after the subroutine has been defined
3506 (W misc) Using the C<:lvalue> declarative syntax to make a Perl
3507 subroutine an lvalue subroutine after it has been defined is
3508 not permitted. To make the subroutine an lvalue subroutine,
3509 add the lvalue attribute to the definition, or put the C<sub
3510 foo :lvalue;> declaration before the definition.
3512 See also L<attributes.pm|attributes>.
3514 =item Magical list constants are not supported
3516 (F) You assigned a magical array to a stash element, and then tried
3517 to use the subroutine from the same slot. You are asking Perl to do
3518 something it cannot do, details subject to change between Perl versions.
3520 =item Malformed integer in [] in pack
3522 (F) Between the brackets enclosing a numeric repeat count only digits
3523 are permitted. See L<perlfunc/pack>.
3525 =item Malformed integer in [] in unpack
3527 (F) Between the brackets enclosing a numeric repeat count only digits
3528 are permitted. See L<perlfunc/pack>.
3530 =item Malformed PERLLIB_PREFIX
3532 (F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form
3539 with nonempty prefix1 and prefix2. If C<prefix1> is indeed a prefix of
3540 a builtin library search path, prefix2 is substituted. The error may
3541 appear if components are not found, or are too long. See
3542 "PERLLIB_PREFIX" in L<perlos2>.
3544 =item Malformed prototype for %s: %s
3546 (F) You tried to use a function with a malformed prototype. The
3547 syntax of function prototypes is given a brief compile-time check for
3548 obvious errors like invalid characters. A more rigorous check is run
3549 when the function is called.
3550 Perhaps the function's author was trying to write a subroutine signature
3551 but didn't enable that feature first (C<use feature 'signatures'>),
3552 so the signature was instead interpreted as a bad prototype.
3554 =item Malformed UTF-8 character%s
3556 (S utf8)(F) Perl detected a string that should be UTF-8, but didn't
3557 comply with UTF-8 encoding rules, or represents a code point whose
3558 ordinal integer value doesn't fit into the word size of the current
3559 platform (overflows). Details as to the exact malformation are given in
3560 the variable, C<%s>, part of the message.
3562 One possible cause is that you set the UTF8 flag yourself for data that
3563 you thought to be in UTF-8 but it wasn't (it was for example legacy 8-bit
3564 data). To guard against this, you can use C<Encode::decode('UTF-8', ...)>.
3566 If you use the C<:encoding(UTF-8)> PerlIO layer for input, invalid byte
3567 sequences are handled gracefully, but if you use C<:utf8>, the flag is set
3568 without validating the data, possibly resulting in this error message.
3570 See also L<Encode/"Handling Malformed Data">.
3572 =item Malformed UTF-8 returned by \N{%s} immediately after '%s'
3574 (F) The charnames handler returned malformed UTF-8.
3576 =item Malformed UTF-8 string in "%s"
3578 (F) This message indicates a bug either in the Perl core or in XS
3579 code. Such code was trying to find out if a character, allegedly
3580 stored internally encoded as UTF-8, was of a given type, such as
3581 being punctuation or a digit. But the character was not encoded
3582 in legal UTF-8. The C<%s> is replaced by a string that can be used
3583 by knowledgeable people to determine what the type being checked
3586 Passing malformed strings was deprecated in Perl 5.18, and
3587 became fatal in Perl 5.26.
3589 =item Malformed UTF-8 string in '%c' format in unpack
3591 (F) You tried to unpack something that didn't comply with UTF-8 encoding
3592 rules and perl was unable to guess how to make more progress.
3594 =item Malformed UTF-8 string in pack
3596 (F) You tried to pack something that didn't comply with UTF-8 encoding
3597 rules and perl was unable to guess how to make more progress.
3599 =item Malformed UTF-8 string in unpack
3601 (F) You tried to unpack something that didn't comply with UTF-8 encoding
3602 rules and perl was unable to guess how to make more progress.
3604 =item Malformed UTF-16 surrogate
3606 (F) Perl thought it was reading UTF-16 encoded character data but while
3607 doing it Perl met a malformed Unicode surrogate.
3609 =item Mandatory parameter follows optional parameter
3611 (F) In a subroutine signature, you wrote something like "$a = undef,
3612 $b", making an earlier parameter optional and a later one mandatory.
3613 Parameters are filled from left to right, so it's impossible for the
3614 caller to omit an earlier one and pass a later one. If you want to act
3615 as if the parameters are filled from right to left, declare the rightmost
3616 optional and then shuffle the parameters around in the subroutine's body.
3618 =item Matched non-Unicode code point 0x%X against Unicode property; may
3621 (S non_unicode) Perl allows strings to contain a superset of
3622 Unicode code points; each code point may be as large as what is storable
3623 in a signed integer on your system, but these may not be accepted by
3624 other languages/systems. This message occurs when you matched a string
3625 containing such a code point against a regular expression pattern, and
3626 the code point was matched against a Unicode property, C<\p{...}> or
3627 C<\P{...}>. Unicode properties are only defined on Unicode code points,
3628 so the result of this match is undefined by Unicode, but Perl (starting
3629 in v5.20) treats non-Unicode code points as if they were typical
3630 unassigned Unicode ones, and matched this one accordingly. Whether a
3631 given property matches these code points or not is specified in
3632 L<perluniprops/Properties accessible through \p{} and \P{}>.
3634 This message is suppressed (unless it has been made fatal) if it is
3635 immaterial to the results of the match if the code point is Unicode or
3636 not. For example, the property C<\p{ASCII_Hex_Digit}> only can match
3637 the 22 characters C<[0-9A-Fa-f]>, so obviously all other code points,
3638 Unicode or not, won't match it. (And C<\P{ASCII_Hex_Digit}> will match
3639 every code point except these 22.)
3641 Getting this message indicates that the outcome of the match arguably
3642 should have been the opposite of what actually happened. If you think
3643 that is the case, you may wish to make the C<non_unicode> warnings
3644 category fatal; if you agree with Perl's decision, you may wish to turn
3647 See L<perlunicode/Beyond Unicode code points> for more information.
3649 =item %s matches null string many times in regex; marked by S<<-- HERE> in
3652 (W regexp) The pattern you've specified would be an infinite loop if the
3653 regular expression engine didn't specifically check for that. The S<<-- HERE>
3654 shows whereabouts in the regular expression the problem was discovered.
3657 =item Maximal count of pending signals (%u) exceeded
3659 (F) Perl aborted due to too high a number of signals pending. This
3660 usually indicates that your operating system tried to deliver signals
3661 too fast (with a very high priority), starving the perl process from
3662 resources it would need to reach a point where it can process signals
3663 safely. (See L<perlipc/"Deferred Signals (Safe Signals)">.)
3665 =item "%s" may clash with future reserved word
3667 (W) This warning may be due to running a perl5 script through a perl4
3668 interpreter, especially if the word that is being warned about is
3671 =item '%' may not be used in pack
3673 (F) You can't pack a string by supplying a checksum, because the
3674 checksumming process loses information, and you can't go the other way.
3675 See L<perlfunc/unpack>.
3677 =item Method for operation %s not found in package %s during blessing
3679 (F) An attempt was made to specify an entry in an overloading table that
3680 doesn't resolve to a valid subroutine. See L<overload>.
3682 =item Method %s not permitted
3684 See L</500 Server error>.
3686 =item Might be a runaway multi-line %s string starting on line %d
3688 (S) An advisory indicating that the previous error may have been caused
3689 by a missing delimiter on a string or pattern, because it eventually
3690 ended earlier on the current line.
3692 =item Misplaced _ in number
3694 (W syntax) An underscore (underbar) in a numeric constant did not
3695 separate two digits.
3697 =item Missing argument for %n in %s
3699 (F) A C<%n> was used in a format string with no corresponding argument for
3700 perl to write the current string length to.
3702 =item Missing argument in %s
3704 (W missing) You called a function with fewer arguments than other
3705 arguments you supplied indicated would be needed.
3707 Currently only emitted when a printf-type format required more
3708 arguments than were supplied, but might be used in the future for
3709 other cases where we can statically determine that arguments to
3710 functions are missing, e.g. for the L<perlfunc/pack> function.
3712 =item Missing argument to -%c
3714 (F) The argument to the indicated command line switch must follow
3715 immediately after the switch, without intervening spaces.
3717 =item Missing braces on \N{}
3719 =item Missing braces on \N{} in regex; marked by S<<-- HERE> in m/%s/
3721 (F) Wrong syntax of character name literal C<\N{charname}> within
3722 double-quotish context. This can also happen when there is a space
3723 (or comment) between the C<\N> and the C<{> in a regex with the C</x> modifier.
3724 This modifier does not change the requirement that the brace immediately
3727 =item Missing braces on \o{}
3729 (F) A C<\o> must be followed immediately by a C<{> in double-quotish context.
3731 =item Missing comma after first argument to %s function
3733 (F) While certain functions allow you to specify a filehandle or an
3734 "indirect object" before the argument list, this ain't one of them.
3736 =item Missing command in piped open
3738 (W pipe) You used the C<open(FH, "| command")> or
3739 C<open(FH, "command |")> construction, but the command was missing or
3742 =item Missing control char name in \c
3744 (F) A double-quoted string ended with "\c", without the required control
3747 =item Missing ']' in prototype for %s : %s
3749 (W illegalproto) A grouping was started with C<[> but never closed with C<]>.
3751 =item Missing name in "%s sub"
3753 (F) The syntax for lexically scoped subroutines requires that
3754 they have a name with which they can be found.
3756 =item Missing $ on loop variable
3758 (F) Apparently you've been programming in B<csh> too much. Variables
3759 are always mentioned with the $ in Perl, unlike in the shells, where it
3760 can vary from one line to the next.
3762 =item (Missing operator before %s?)
3764 (S syntax) This is an educated guess made in conjunction with the message
3765 "%s found where operator expected". Often the missing operator is a comma.
3767 =item Missing or undefined argument to %s
3769 (F) You tried to call require or do with no argument or with an undefined
3770 value as an argument. Require expects either a package name or a
3771 file-specification as an argument; do expects a filename. See
3772 L<perlfunc/require EXPR> and L<perlfunc/do EXPR>.
3774 =item Missing right brace on \%c{} in regex; marked by S<<-- HERE> in m/%s/
3776 (F) Missing right brace in C<\x{...}>, C<\p{...}>, C<\P{...}>, or C<\N{...}>.
3778 =item Missing right brace on \N{}
3780 =item Missing right brace on \N{} or unescaped left brace after \N
3782 (F) C<\N> has two meanings.
3784 The traditional one has it followed by a name enclosed in braces,
3785 meaning the character (or sequence of characters) given by that
3786 name. Thus C<\N{ASTERISK}> is another way of writing C<*>, valid in both
3787 double-quoted strings and regular expression patterns. In patterns,
3788 it doesn't have the meaning an unescaped C<*> does.
3790 Starting in Perl 5.12.0, C<\N> also can have an additional meaning (only)
3791 in patterns, namely to match a non-newline character. (This is short
3792 for C<[^\n]>, and like C<.> but is not affected by the C</s> regex modifier.)
3794 This can lead to some ambiguities. When C<\N> is not followed immediately
3795 by a left brace, Perl assumes the C<[^\n]> meaning. Also, if the braces
3796 form a valid quantifier such as C<\N{3}> or C<\N{5,}>, Perl assumes that this
3797 means to match the given quantity of non-newlines (in these examples,
3798 3; and 5 or more, respectively). In all other case, where there is a
3799 C<\N{> and a matching C<}>, Perl assumes that a character name is desired.
3801 However, if there is no matching C<}>, Perl doesn't know if it was
3802 mistakenly omitted, or if C<[^\n]{> was desired, and raises this error.
3803 If you meant the former, add the right brace; if you meant the latter,
3804 escape the brace with a backslash, like so: C<\N\{>
3806 =item Missing right curly or square bracket
3808 (F) The lexer counted more opening curly or square brackets than closing
3809 ones. As a general rule, you'll find it's missing near the place you
3812 =item (Missing semicolon on previous line?)
3814 (S syntax) This is an educated guess made in conjunction with the message
3815 "%s found where operator expected". Don't automatically put a semicolon on
3816 the previous line just because you saw this message.
3818 =item Modification of a read-only value attempted
3820 (F) You tried, directly or indirectly, to change the value of a
3821 constant. You didn't, of course, try "2 = 1", because the compiler
3822 catches that. But an easy way to do the same thing is:
3824 sub mod { $_[0] = 1 }
3827 Another way is to assign to a substr() that's off the end of the string.
3829 Yet another way is to assign to a C<foreach> loop I<VAR> when I<VAR>
3830 is aliased to a constant in the look I<LIST>:
3833 foreach my $n ($x, 2) {
3834 $n *= 2; # modifies the $x, but fails on attempt to
3837 L<PerlIO::scalar> will also produce this message as a warning if you
3838 attempt to open a read-only scalar for writing.
3840 =item Modification of non-creatable array value attempted, %s
3842 (F) You tried to make an array value spring into existence, and the
3843 subscript was probably negative, even counting from end of the array
3846 =item Modification of non-creatable hash value attempted, %s
3848 (P) You tried to make a hash value spring into existence, and it
3849 couldn't be created for some peculiar reason.
3851 =item Module name must be constant
3853 (F) Only a bare module name is allowed as the first argument to a "use".
3855 =item Module name required with -%c option
3857 (F) The C<-M> or C<-m> options say that Perl should load some module, but
3858 you omitted the name of the module. Consult
3859 L<perlrun|perlrun/-m[-]module> for full details about C<-M> and C<-m>.
3861 =item More than one argument to '%s' open
3863 (F) The C<open> function has been asked to open multiple files. This
3864 can happen if you are trying to open a pipe to a command that takes a
3865 list of arguments, but have forgotten to specify a piped open mode.
3866 See L<perlfunc/open> for details.
3868 =item mprotect for COW string %p %u failed with %d
3870 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_COW (see
3871 L<perlguts/"Copy on Write">), but a shared string buffer
3872 could not be made read-only.
3874 =item mprotect for %p %u failed with %d
3876 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_OPS (see L<perlhacktips>),
3877 but an op tree could not be made read-only.
3879 =item mprotect RW for COW string %p %u failed with %d
3881 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_COW (see
3882 L<perlguts/"Copy on Write">), but a read-only shared string
3883 buffer could not be made mutable.
3885 =item mprotect RW for %p %u failed with %d
3887 (S) You compiled perl with B<-D>PERL_DEBUG_READONLY_OPS (see
3888 L<perlhacktips>), but a read-only op tree could not be made
3889 mutable before freeing the ops.
3891 =item msg%s not implemented
3893 (F) You don't have System V message IPC on your system.
3895 =item Multidimensional hash lookup is disabled
3897 (F) You supplied a list of subscripts to a hash lookup under
3898 C<< no feature "multidimensional"; >>, eg:
3902 which by default acts like:
3904 $z = $foo{join($;, $x, $y)};
3906 =item Multidimensional syntax %s not supported
3908 (W syntax) Multidimensional arrays aren't written like C<$foo[1,2,3]>.
3909 They're written like C<$foo[1][2][3]>, as in C.
3911 =item Multiple slurpy parameters not allowed
3913 (F) In subroutine signatures, a slurpy parameter (C<@> or C<%>) must be
3914 the last parameter, and there must not be more than one of them; for
3917 sub foo ($a, @b) {} # legal
3918 sub foo ($a, @b, %) {} # invalid
3920 =item '/' must follow a numeric type in unpack
3922 (F) You had an unpack template that contained a '/', but this did not
3923 follow some unpack specification producing a numeric value.
3924 See L<perlfunc/pack>.
3926 =item %s must not be a named sequence in transliteration operator
3928 (F) Transliteration (C<tr///> and C<y///>) transliterates individual
3929 characters. But a named sequence by definition is more than an
3930 individual character, and hence doing this operation on it doesn't make
3933 =item "my sub" not yet implemented
3935 (F) Lexically scoped subroutines are not yet implemented. Don't try
3938 =item "my" subroutine %s can't be in a package
3940 (F) Lexically scoped subroutines aren't in a package, so it doesn't make
3941 sense to try to declare one with a package qualifier on the front.
3943 =item "my %s" used in sort comparison
3945 (W syntax) The package variables $a and $b are used for sort comparisons.
3946 You used $a or $b in as an operand to the C<< <=> >> or C<cmp> operator inside a
3947 sort comparison block, and the variable had earlier been declared as a
3948 lexical variable. Either qualify the sort variable with the package
3949 name, or rename the lexical variable.
3951 =item "my" variable %s can't be in a package
3953 (F) Lexically scoped variables aren't in a package, so it doesn't make
3954 sense to try to declare one with a package qualifier on the front. Use
3955 local() if you want to localize a package variable.
3957 =item Name "%s::%s" used only once: possible typo
3959 (W once) Typographical errors often show up as unique variable
3960 names. If you had a good reason for having a unique name, then
3961 just mention it again somehow to suppress the message. The C<our>
3962 declaration is also provided for this purpose.
3964 NOTE: This warning detects package symbols that have been used
3965 only once. This means lexical variables will never trigger this
3966 warning. It also means that all of the package variables $c, @c,
3967 %c, as well as *c, &c, sub c{}, c(), and c (the filehandle or
3968 format) are considered the same; if a program uses $c only once
3969 but also uses any of the others it will not trigger this warning.
3970 Symbols beginning with an underscore and symbols using special
3971 identifiers (q.v. L<perldata>) are exempt from this warning.
3973 =item Need exactly 3 octal digits in regex; marked by S<<-- HERE> in m/%s/
3975 (F) Within S<C<(?[ ])>>, all constants interpreted as octal need to be
3976 exactly 3 digits long. This helps catch some ambiguities. If your
3977 constant is too short, add leading zeros, like
3979 (?[ [ \078 ] ]) # Syntax error!
3980 (?[ [ \0078 ] ]) # Works
3981 (?[ [ \007 8 ] ]) # Clearer
3983 The maximum number this construct can express is C<\777>. If you
3984 need a larger one, you need to use L<\o{}|perlrebackslash/Octal escapes> instead. If you meant
3985 two separate things, you need to separate them:
3987 (?[ [ \7776 ] ]) # Syntax error!
3988 (?[ [ \o{7776} ] ]) # One meaning
3989 (?[ [ \777 6 ] ]) # Another meaning
3990 (?[ [ \777 \006 ] ]) # Still another
3992 =item Negative '/' count in unpack
3994 (F) The length count obtained from a length/code unpack operation was
3995 negative. See L<perlfunc/pack>.
3997 =item Negative length
3999 (F) You tried to do a read/write/send/recv operation with a buffer
4000 length that is less than 0. This is difficult to imagine.
4002 =item Negative offset to vec in lvalue context
4004 (F) When C<vec> is called in an lvalue context, the second argument must be
4005 greater than or equal to zero.
4007 =item Negative repeat count does nothing
4009 (W numeric) You tried to execute the
4010 L<C<x>|perlop/Multiplicative Operators> repetition operator fewer than 0
4011 times, which doesn't make sense.
4013 =item Nested quantifiers in regex; marked by S<<-- HERE> in m/%s/
4015 (F) You can't quantify a quantifier without intervening parentheses.
4016 So things like ** or +* or ?* are illegal. The S<<-- HERE> shows
4017 whereabouts in the regular expression the problem was discovered.
4019 Note that the minimal matching quantifiers, C<*?>, C<+?>, and
4020 C<??> appear to be nested quantifiers, but aren't. See L<perlre>.
4022 =item %s never introduced
4024 (S internal) The symbol in question was declared but somehow went out of
4025 scope before it could possibly have been used.
4027 =item next::method/next::can/maybe::next::method cannot find enclosing method
4029 (F) C<next::method> needs to be called within the context of a
4030 real method in a real package, and it could not find such a context.
4033 =item \N in a character class must be a named character: \N{...} in regex;
4034 marked by S<<-- HERE> in m/%s/
4036 (F) The new (as of Perl 5.12) meaning of C<\N> as C<[^\n]> is not valid in a
4037 bracketed character class, for the same reason that C<.> in a character
4038 class loses its specialness: it matches almost everything, which is
4039 probably not what you want.
4041 =item \N{} here is restricted to one character in regex; marked by <-- HERE in m/%s/
4043 (F) Named Unicode character escapes (C<\N{...}>) may return a
4044 multi-character sequence. Even though a character class is
4045 supposed to match just one character of input, perl will match the
4046 whole thing correctly, except under certain conditions. These currently
4051 =item When the class is inverted (C<[^...]>)
4053 The mathematically logical behavior for what matches when inverting
4054 is very different from what people expect, so we have decided to
4057 =item The escape is the beginning or final end point of a range
4059 Similarly unclear is what should be generated when the
4060 C<\N{...}> is used as one of the end points of the range, such as in
4062 [\x{41}-\N{ARABIC SEQUENCE YEH WITH HAMZA ABOVE WITH AE}]
4064 What is meant here is unclear, as the C<\N{...}> escape is a sequence
4065 of code points, so this is made an error.
4067 =item In a regex set
4069 The syntax S<C<(?[ ])>> in a regular expression yields a list of
4070 single code points, none can be a sequence.
4074 =item No %s allowed while running setuid
4076 (F) Certain operations are deemed to be too insecure for a setuid or
4077 setgid script to even be allowed to attempt. Generally speaking there
4078 will be another way to do what you want that is, if not secure, at least
4079 securable. See L<perlsec>.
4081 =item No code specified for -%c
4083 (F) Perl's B<-e> and B<-E> command-line options require an argument. If
4084 you want to run an empty program, pass the empty string as a separate
4085 argument or run a program consisting of a single 0 or 1:
4091 =item No comma allowed after %s
4093 (F) A list operator that has a filehandle or "indirect object" is
4094 not allowed to have a comma between that and the following arguments.
4095 Otherwise it'd be just another one of the arguments.
4097 One possible cause for this is that you expected to have imported
4098 a constant to your name space with B<use> or B<import> while no such
4099 importing took place, it may for example be that your operating
4100 system does not support that particular constant. Hopefully you did
4101 use an explicit import list for the constants you expect to see;
4102 please see L<perlfunc/use> and L<perlfunc/import>. While an
4103 explicit import list would probably have caught this error earlier
4104 it naturally does not remedy the fact that your operating system
4105 still does not support that constant. Maybe you have a typo in
4106 the constants of the symbol import list of B<use> or B<import> or in the
4107 constant name at the line where this error was triggered?
4109 =item No command into which to pipe on command line
4111 (F) An error peculiar to VMS. Perl handles its own command line
4112 redirection, and found a '|' at the end of the command line, so it
4113 doesn't know where you want to pipe the output from this command.
4115 =item No DB::DB routine defined
4117 (F) The currently executing code was compiled with the B<-d> switch, but
4118 for some reason the current debugger (e.g. F<perl5db.pl> or a C<Devel::>
4119 module) didn't define a routine to be called at the beginning of each
4122 =item No dbm on this machine
4124 (P) This is counted as an internal error, because every machine should
4125 supply dbm nowadays, because Perl comes with SDBM. See L<SDBM_File>.
4127 =item No DB::sub routine defined
4129 (F) The currently executing code was compiled with the B<-d> switch, but
4130 for some reason the current debugger (e.g. F<perl5db.pl> or a C<Devel::>
4131 module) didn't define a C<DB::sub> routine to be called at the beginning
4132 of each ordinary subroutine call.
4134 =item No digits found for %s literal
4136 (F) No hexadecimal digits were found following C<0x> or no binary digits
4137 were found following C<0b>.
4139 =item No directory specified for -I
4141 (F) The B<-I> command-line switch requires a directory name as part of the
4142 I<same> argument. Use B<-Ilib>, for instance. B<-I lib> won't work.
4144 =item No error file after 2> or 2>> on command line
4146 (F) An error peculiar to VMS. Perl handles its own command line
4147 redirection, and found a '2>' or a '2>>' on the command line, but can't
4148 find the name of the file to which to write data destined for stderr.
4150 =item No group ending character '%c' found in template
4152 (F) A pack or unpack template has an opening '(' or '[' without its
4153 matching counterpart. See L<perlfunc/pack>.
4155 =item No input file after < on command line
4157 (F) An error peculiar to VMS. Perl handles its own command line
4158 redirection, and found a '<' on the command line, but can't find the
4159 name of the file from which to read data for stdin.
4161 =item No next::method '%s' found for %s
4163 (F) C<next::method> found no further instances of this method name
4164 in the remaining packages of the MRO of this class. If you don't want
4165 it throwing an exception, use C<maybe::next::method>
4166 or C<next::can>. See L<mro>.
4168 =item Non-finite repeat count does nothing
4170 (W numeric) You tried to execute the
4171 L<C<x>|perlop/Multiplicative Operators> repetition operator C<Inf> (or
4172 C<-Inf>) or C<NaN> times, which doesn't make sense.
4174 =item Non-hex character in regex; marked by S<<-- HERE> in m/%s/
4176 (F) In a regular expression, there was a non-hexadecimal character where
4177 a hex one was expected, like
4182 =item Non-hex character '%c' terminates \x early. Resolved as "%s"
4184 (W digit) In parsing a hexadecimal numeric constant, a character was
4185 unexpectedly encountered that isn't hexadecimal. The resulting value
4188 Note that, within braces, every character starting with the first
4189 non-hexadecimal up to the ending brace is ignored.
4191 =item Non-octal character in regex; marked by S<<-- HERE> in m/%s/
4193 (F) In a regular expression, there was a non-octal character where
4194 an octal one was expected, like
4198 =item Non-octal character '%c' terminates \o early. Resolved as "%s"
4200 (W digit) In parsing an octal numeric constant, a character was
4201 unexpectedly encountered that isn't octal. The resulting value
4204 When not using C<\o{...}>, you wrote something like C<\08>, or C<\179>
4205 in a double-quotish string. The resolution is as indicated, with all
4206 but the last digit treated as a single character, specified in octal.
4207 The last digit is the next character in the string. To tell Perl that
4208 this is indeed what you want, you can use the C<\o{ }> syntax, or use
4209 exactly three digits to specify the octal for the character.
4211 Note that, within braces, every character starting with the first
4212 non-octal up to the ending brace is ignored.
4214 =item "no" not allowed in expression
4216 (F) The "no" keyword is recognized and executed at compile time, and
4217 returns no useful value. See L<perlmod>.
4219 =item Non-string passed as bitmask
4221 (W misc) A number has been passed as a bitmask argument to select().
4222 Use the vec() function to construct the file descriptor bitmasks for
4223 select. See L<perlfunc/select>.
4225 =item No output file after > on command line
4227 (F) An error peculiar to VMS. Perl handles its own command line
4228 redirection, and found a lone '>' at the end of the command line, so it
4229 doesn't know where you wanted to redirect stdout.
4231 =item No output file after > or >> on command line
4233 (F) An error peculiar to VMS. Perl handles its own command line
4234 redirection, and found a '>' or a '>>' on the command line, but can't
4235 find the name of the file to which to write data destined for stdout.
4237 =item No package name allowed for subroutine %s in "our"
4239 =item No package name allowed for variable %s in "our"
4241 (F) Fully qualified subroutine and variable names are not allowed in "our"
4242 declarations, because that doesn't make much sense under existing rules.
4243 Such syntax is reserved for future extensions.
4245 =item No Perl script found in input
4247 (F) You called C<perl -x>, but no line was found in the file beginning
4248 with #! and containing the word "perl".
4250 =item No setregid available
4252 (F) Configure didn't find anything resembling the setregid() call for
4255 =item No setreuid available
4257 (F) Configure didn't find anything resembling the setreuid() call for
4260 =item No such class %s
4262 (F) You provided a class qualifier in a "my", "our" or "state"
4263 declaration, but this class doesn't exist at this point in your program.
4265 =item No such class field "%s" in variable %s of type %s
4267 (F) You tried to access a key from a hash through the indicated typed
4268 variable but that key is not allowed by the package of the same type.
4269 The indicated package has restricted the set of allowed keys using the
4272 =item No such hook: %s
4274 (F) You specified a signal hook that was not recognized by Perl.
4275 Currently, Perl accepts C<__DIE__> and C<__WARN__> as valid signal hooks.
4277 =item No such pipe open
4279 (P) An error peculiar to VMS. The internal routine my_pclose() tried to
4280 close a pipe which hadn't been opened. This should have been caught
4281 earlier as an attempt to close an unopened filehandle.
4283 =item No such signal: SIG%s
4285 (W signal) You specified a signal name as a subscript to %SIG that was
4286 not recognized. Say C<kill -l> in your shell to see the valid signal
4287 names on your system.
4289 =item No Unicode property value wildcard matches:
4291 (W regexp) You specified a wildcard for a Unicode property value, but
4292 there is no property value in the current Unicode release that matches
4293 it. Check your spelling.
4295 =item Not a CODE reference
4297 (F) Perl was trying to evaluate a reference to a code value (that is, a
4298 subroutine), but found a reference to something else instead. You can
4299 use the ref() function to find out what kind of ref it really was. See
4302 =item Not a GLOB reference
4304 (F) Perl was trying to evaluate a reference to a "typeglob" (that is, a
4305 symbol table entry that looks like C<*foo>), but found a reference to
4306 something else instead. You can use the ref() function to find out what
4307 kind of ref it really was. See L<perlref>.
4309 =item Not a HASH reference
4311 (F) Perl was trying to evaluate a reference to a hash value, but found a
4312 reference to something else instead. You can use the ref() function to
4313 find out what kind of ref it really was. See L<perlref>.
4315 =item '#' not allowed immediately following a sigil in a subroutine signature
4317 (F) In a subroutine signature definition, a comment following a sigil
4318 (C<$>, C<@> or C<%>), needs to be separated by whitespace or a comma etc., in
4319 particular to avoid confusion with the C<$#> variable. For example:
4322 sub f ($# ignore first arg
4325 sub f ($, # ignore first arg
4328 =item Not an ARRAY reference
4330 (F) Perl was trying to evaluate a reference to an array value, but found
4331 a reference to something else instead. You can use the ref() function
4332 to find out what kind of ref it really was. See L<perlref>.
4334 =item Not a SCALAR reference
4336 (F) Perl was trying to evaluate a reference to a scalar value, but found
4337 a reference to something else instead. You can use the ref() function
4338 to find out what kind of ref it really was. See L<perlref>.
4340 =item Not a subroutine reference
4342 (F) Perl was trying to evaluate a reference to a code value (that is, a
4343 subroutine), but found a reference to something else instead. You can
4344 use the ref() function to find out what kind of ref it really was. See
4347 =item Not a subroutine reference in overload table
4349 (F) An attempt was made to specify an entry in an overloading table that
4350 doesn't somehow point to a valid subroutine. See L<overload>.
4352 =item Not enough arguments for %s
4354 (F) The function requires more arguments than you specified.
4356 =item Not enough format arguments
4358 (W syntax) A format specified more picture fields than the next line
4359 supplied. See L<perlform>.
4363 (A) You've accidentally run your script through the Bourne shell instead
4364 of Perl. Check the #! line, or manually feed your script into Perl
4367 =item no UTC offset information; assuming local time is UTC
4369 (S) A warning peculiar to VMS. Perl was unable to find the local
4370 timezone offset, so it's assuming that local system time is equivalent
4371 to UTC. If it's not, define the logical name
4372 F<SYS$TIMEZONE_DIFFERENTIAL> to translate to the number of seconds which
4373 need to be added to UTC to get local time.
4375 =item NULL OP IN RUN
4377 (S debugging) Some internal routine called run() with a null opcode
4380 =item Null picture in formline
4382 (F) The first argument to formline must be a valid format picture
4383 specification. It was found to be empty, which probably means you
4384 supplied it an uninitialized value. See L<perlform>.
4388 (P) An attempt was made to realloc NULL.
4390 =item NULL regexp argument
4392 (P) The internal pattern matching routines blew it big time.
4394 =item NULL regexp parameter
4396 (P) The internal pattern matching routines are out of their gourd.
4398 =item Number too long
4400 (F) Perl limits the representation of decimal numbers in programs to
4401 about 250 characters. You've exceeded that length. Future
4402 versions of Perl are likely to eliminate this arbitrary limitation. In
4403 the meantime, try using scientific notation (e.g. "1e6" instead of
4406 =item Number with no digits
4408 (F) Perl was looking for a number but found nothing that looked like
4409 a number. This happens, for example with C<\o{}>, with no number between
4412 =item Numeric format result too large
4414 (F) The length of the result of a numeric format supplied to sprintf()
4415 or printf() would have been too large for the underlying C function to
4416 report. This limit is typically 2GB.
4418 =item Numeric variables with more than one digit may not start with '0'
4420 (F) The only numeric variable which is allowed to start with a 0 is C<$0>,
4421 and you mentioned a variable that starts with 0 that has more than one
4422 digit. You probably want to remove the leading 0, or if the intent was
4423 to express a variable name in octal you should convert to decimal.
4425 =item Octal number > 037777777777 non-portable
4427 (W portable) The octal number you specified is larger than 2**32-1
4428 (4294967295) and therefore non-portable between systems. See
4429 L<perlport> for more on portability concerns.
4431 =item Odd name/value argument for subroutine '%s'
4433 (F) A subroutine using a slurpy hash parameter in its signature
4434 received an odd number of arguments to populate the hash. It requires
4435 the arguments to be paired, with the same number of keys as values.
4436 The caller of the subroutine is presumably at fault.
4438 The message attempts to include the name of the called subroutine. If the
4439 subroutine has been aliased, the subroutine's original name will be shown,
4440 regardless of what name the caller used.
4442 =item Odd number of arguments for overload::constant
4444 (W overload) The call to overload::constant contained an odd number of
4445 arguments. The arguments should come in pairs.
4447 =item Odd number of elements in anonymous hash
4449 (W misc) You specified an odd number of elements to initialize a hash,
4450 which is odd, because hashes come in key/value pairs.
4452 =item Odd number of elements in hash assignment
4454 (W misc) You specified an odd number of elements to initialize a hash,
4455 which is odd, because hashes come in key/value pairs.
4457 =item Offset outside string
4459 (F)(W layer) You tried to do a read/write/send/recv/seek operation
4460 with an offset pointing outside the buffer. This is difficult to
4461 imagine. The sole exceptions to this are that zero padding will
4462 take place when going past the end of the string when either
4463 C<sysread()>ing a file, or when seeking past the end of a scalar opened
4464 for I/O (in anticipation of future reads and to imitate the behavior
4467 =item Old package separator used in string
4469 (W syntax) You used the old package separator, "'", in a variable
4470 named inside a double-quoted string; e.g., C<"In $name's house">. This
4471 is equivalent to C<"In $name::s house">. If you meant the former, put
4472 a backslash before the apostrophe (C<"In $name\'s house">).
4474 =item %s() on unopened %s
4476 (W unopened) An I/O operation was attempted on a filehandle that was
4477 never initialized. You need to do an open(), a sysopen(), or a socket()
4478 call, or call a constructor from the FileHandle package.
4480 =item -%s on unopened filehandle %s
4482 (W unopened) You tried to invoke a file test operator on a filehandle
4483 that isn't open. Check your control flow. See also L<perlfunc/-X>.
4487 (S internal) An internal warning that the grammar is screwed up.
4491 (S internal) An internal warning that the grammar is screwed up.
4493 =item Operand with no preceding operator in regex; marked by S<<-- HERE> in
4496 (F) You wrote something like
4498 (?[ \p{Digit} \p{Thai} ])
4500 There are two operands, but no operator giving how you want to combine
4503 =item Operation "%s": no method found, %s
4505 (F) An attempt was made to perform an overloaded operation for which no
4506 handler was defined. While some handlers can be autogenerated in terms
4507 of other handlers, there is no default handler for any operation, unless
4508 the C<fallback> overloading key is specified to be true. See L<overload>.
4510 =item Operation "%s" returns its argument for non-Unicode code point 0x%X
4512 (S non_unicode) You performed an operation requiring Unicode rules
4513 on a code point that is not in Unicode, so what it should do is not
4514 defined. Perl has chosen to have it do nothing, and warn you.
4516 If the operation shown is "ToFold", it means that case-insensitive
4517 matching in a regular expression was done on the code point.
4519 If you know what you are doing you can turn off this warning by
4520 C<no warnings 'non_unicode';>.
4522 =item Operation "%s" returns its argument for UTF-16 surrogate U+%X
4524 (S surrogate) You performed an operation requiring Unicode
4525 rules on a Unicode surrogate. Unicode frowns upon the use
4526 of surrogates for anything but storing strings in UTF-16, but
4527 rules are (reluctantly) defined for the surrogates, and
4528 they are to do nothing for this operation. Because the use of
4529 surrogates can be dangerous, Perl warns.
4531 If the operation shown is "ToFold", it means that case-insensitive
4532 matching in a regular expression was done on the code point.
4534 If you know what you are doing you can turn off this warning by
4535 C<no warnings 'surrogate';>.
4537 =item Operator or semicolon missing before %s
4539 (S ambiguous) You used a variable or subroutine call where the parser
4540 was expecting an operator. The parser has assumed you really meant to
4541 use an operator, but this is highly likely to be incorrect. For
4542 example, if you say "*foo *foo" it will be interpreted as if you said
4545 =item Optional parameter lacks default expression
4547 (F) In a subroutine signature, you wrote something like "$a =", making a
4548 named optional parameter without a default value. A nameless optional
4549 parameter is permitted to have no default value, but a named one must
4550 have a specific default. You probably want "$a = undef".
4552 =item "our" variable %s redeclared
4554 (W shadow) You seem to have already declared the same global once before
4555 in the current lexical scope.
4557 =item Out of memory!
4559 (X) The malloc() function returned 0, indicating there was insufficient
4560 remaining memory (or virtual memory) to satisfy the request. Perl has
4561 no option but to exit immediately.
4563 At least in Unix you may be able to get past this by increasing your
4564 process datasize limits: in csh/tcsh use C<limit> and
4565 C<limit datasize n> (where C<n> is the number of kilobytes) to check
4566 the current limits and change them, and in ksh/bash/zsh use C<ulimit -a>
4567 and C<ulimit -d n>, respectively.
4569 =item Out of memory during %s extend
4571 (X) An attempt was made to extend an array, a list, or a string beyond
4572 the largest possible memory allocation.
4574 =item Out of memory during "large" request for %s
4576 (F) The malloc() function returned 0, indicating there was insufficient
4577 remaining memory (or virtual memory) to satisfy the request. However,
4578 the request was judged large enough (compile-time default is 64K), so a
4579 possibility to shut down by trapping this error is granted.
4581 =item Out of memory during request for %s
4583 (X)(F) The malloc() function returned 0, indicating there was
4584 insufficient remaining memory (or virtual memory) to satisfy the
4587 The request was judged to be small, so the possibility to trap it
4588 depends on the way perl was compiled. By default it is not trappable.
4589 However, if compiled for this, Perl may use the contents of C<$^M> as an
4590 emergency pool after die()ing with this message. In this case the error
4591 is trappable I<once>, and the error message will include the line and file
4592 where the failed request happened.
4594 =item Out of memory during ridiculously large request
4596 (F) You can't allocate more than 2^31+"small amount" bytes. This error
4597 is most likely to be caused by a typo in the Perl program. e.g.,
4598 C<$arr[time]> instead of C<$arr[$time]>.
4600 =item Out of memory for yacc stack
4602 (F) The yacc parser wanted to grow its stack so it could continue
4603 parsing, but realloc() wouldn't give it more memory, virtual or
4606 =item '.' outside of string in pack
4608 (F) The argument to a '.' in your template tried to move the working
4609 position to before the start of the packed string being built.
4611 =item '@' outside of string in unpack
4613 (F) You had a template that specified an absolute position outside
4614 the string being unpacked. See L<perlfunc/pack>.
4616 =item '@' outside of string with malformed UTF-8 in unpack
4618 (F) You had a template that specified an absolute position outside
4619 the string being unpacked. The string being unpacked was also invalid
4620 UTF-8. See L<perlfunc/pack>.
4622 =item overload arg '%s' is invalid
4624 (W overload) The L<overload> pragma was passed an argument it did not
4625 recognize. Did you mistype an operator?
4627 =item Overloaded dereference did not return a reference
4629 (F) An object with an overloaded dereference operator was dereferenced,
4630 but the overloaded operation did not return a reference. See
4633 =item Overloaded qr did not return a REGEXP
4635 (F) An object with a C<qr> overload was used as part of a match, but the
4636 overloaded operation didn't return a compiled regexp. See L<overload>.
4638 =item %s package attribute may clash with future reserved word: %s
4640 (W reserved) A lowercase attribute name was used that had a
4641 package-specific handler. That name might have a meaning to Perl itself
4642 some day, even though it doesn't yet. Perhaps you should use a
4643 mixed-case attribute name, instead. See L<attributes>.
4645 =item pack/unpack repeat count overflow
4647 (F) You can't specify a repeat count so large that it overflows your
4648 signed integers. See L<perlfunc/pack>.
4652 (W io) A single call to write() produced more lines than can fit on a
4653 page. See L<perlform>.
4657 (P) An internal error.
4659 =item panic: attempt to call %s in %s
4661 (P) One of the file test operators entered a code branch that calls
4662 an ACL related-function, but that function is not available on this
4663 platform. Earlier checks mean that it should not be possible to
4664 enter this branch on this platform.
4666 =item panic: child pseudo-process was never scheduled
4668 (P) A child pseudo-process in the ithreads implementation on Windows
4669 was not scheduled within the time period allowed and therefore was not
4670 able to initialize properly.
4672 =item panic: ck_grep, type=%u
4674 (P) Failed an internal consistency check trying to compile a grep.
4676 =item panic: corrupt saved stack index %ld
4678 (P) The savestack was requested to restore more localized values than
4679 there are in the savestack.
4681 =item panic: del_backref
4683 (P) Failed an internal consistency check while trying to reset a weak
4686 =item panic: do_subst
4688 (P) The internal pp_subst() routine was called with invalid operational
4691 =item panic: do_trans_%s
4693 (P) The internal do_trans routines were called with invalid operational
4696 =item panic: fold_constants JMPENV_PUSH returned %d
4698 (P) While attempting folding constants an exception other than an C<eval>
4701 =item panic: frexp: %f
4703 (P) The library function frexp() failed, making printf("%f") impossible.
4705 =item panic: goto, type=%u, ix=%ld
4707 (P) We popped the context stack to a context with the specified label,
4708 and then discovered it wasn't a context we know how to do a goto in.
4710 =item panic: gp_free failed to free glob pointer
4712 (P) The internal routine used to clear a typeglob's entries tried
4713 repeatedly, but each time something re-created entries in the glob.
4714 Most likely the glob contains an object with a reference back to
4715 the glob and a destructor that adds a new object to the glob.
4717 =item panic: INTERPCASEMOD, %s
4719 (P) The lexer got into a bad state at a case modifier.
4721 =item panic: INTERPCONCAT, %s
4723 (P) The lexer got into a bad state parsing a string with brackets.
4725 =item panic: kid popen errno read
4727 (F) A forked child returned an incomprehensible message about its errno.
4729 =item panic: last, type=%u
4731 (P) We popped the context stack to a block context, and then discovered
4732 it wasn't a block context.
4734 =item panic: leave_scope clearsv
4736 (P) A writable lexical variable became read-only somehow within the
4739 =item panic: leave_scope inconsistency %u
4741 (P) The savestack probably got out of sync. At least, there was an
4742 invalid enum on the top of it.
4744 =item panic: magic_killbackrefs
4746 (P) Failed an internal consistency check while trying to reset all weak
4747 references to an object.
4749 =item panic: malloc, %s
4751 (P) Something requested a negative number of bytes of malloc.
4753 =item panic: memory wrap
4755 (P) Something tried to allocate either more memory than possible or a
4758 =item panic: pad_alloc, %p!=%p
4760 (P) The compiler got confused about which scratch pad it was allocating
4761 and freeing temporaries and lexicals from.
4763 =item panic: pad_free curpad, %p!=%p
4765 (P) The compiler got confused about which scratch pad it was allocating
4766 and freeing temporaries and lexicals from.
4768 =item panic: pad_free po
4770 (P) A zero scratch pad offset was detected internally. An attempt was
4771 made to free a target that had not been allocated to begin with.
4773 =item panic: pad_reset curpad, %p!=%p
4775 (P) The compiler got confused about which scratch pad it was allocating
4776 and freeing temporaries and lexicals from.
4778 =item panic: pad_sv po
4780 (P) A zero scratch pad offset was detected internally. Most likely
4781 an operator needed a target but that target had not been allocated
4782 for whatever reason.
4784 =item panic: pad_swipe curpad, %p!=%p
4786 (P) The compiler got confused about which scratch pad it was allocating
4787 and freeing temporaries and lexicals from.
4789 =item panic: pad_swipe po
4791 (P) An invalid scratch pad offset was detected internally.
4793 =item panic: pp_iter, type=%u
4795 (P) The foreach iterator got called in a non-loop context frame.
4797 =item panic: pp_match%s
4799 (P) The internal pp_match() routine was called with invalid operational
4802 =item panic: realloc, %s
4804 (P) Something requested a negative number of bytes of realloc.
4806 =item panic: reference miscount on nsv in sv_replace() (%d != 1)
4808 (P) The internal sv_replace() function was handed a new SV with a
4809 reference count other than 1.
4811 =item panic: restartop in %s
4813 (P) Some internal routine requested a goto (or something like it), and
4814 didn't supply the destination.
4816 =item panic: return, type=%u
4818 (P) We popped the context stack to a subroutine or eval context, and
4819 then discovered it wasn't a subroutine or eval context.
4821 =item panic: scan_num, %s
4823 (P) scan_num() got called on something that wasn't a number.
4825 =item panic: Sequence (?{...}): no code block found in regex m/%s/
4827 (P) While compiling a pattern that has embedded (?{}) or (??{}) code
4828 blocks, perl couldn't locate the code block that should have already been
4829 seen and compiled by perl before control passed to the regex compiler.
4831 =item panic: strxfrm() gets absurd - a => %u, ab => %u
4833 (P) The interpreter's sanity check of the C function strxfrm() failed.
4834 In your current locale the returned transformation of the string "ab"
4835 is shorter than that of the string "a", which makes no sense.
4837 =item panic: sv_chop %s
4839 (P) The sv_chop() routine was passed a position that is not within the
4840 scalar's string buffer.
4842 =item panic: sv_insert, midend=%p, bigend=%p
4844 (P) The sv_insert() routine was told to remove more string than there
4847 =item panic: top_env
4849 (P) The compiler attempted to do a goto, or something weird like that.
4851 =item panic: unimplemented op %s (#%d) called
4853 (P) The compiler is screwed up and attempted to use an op that isn't
4854 permitted at run time.
4856 =item panic: unknown OA_*: %x
4858 (P) The internal routine that handles arguments to C<&CORE::foo()>
4859 subroutine calls was unable to determine what type of arguments
4862 =item panic: utf16_to_utf8: odd bytelen
4864 (P) Something tried to call utf16_to_utf8 with an odd (as opposed
4865 to even) byte length.
4867 =item panic: utf16_to_utf8_reversed: odd bytelen
4869 (P) Something tried to call utf16_to_utf8_reversed with an odd (as opposed
4870 to even) byte length.
4872 =item panic: yylex, %s
4874 (P) The lexer got into a bad state while processing a case modifier.
4876 =item Parentheses missing around "%s" list
4878 (W parenthesis) You said something like
4884 my ($foo, $bar) = @_;
4886 Remember that "my", "our", "local" and "state" bind tighter than comma.
4888 =item Parsing code internal error (%s)
4890 (F) Parsing code supplied by an extension violated the parser's API in
4893 =item Pattern subroutine nesting without pos change exceeded limit in regex
4895 (F) You used a pattern that uses too many nested subpattern calls without
4896 consuming any text. Restructure the pattern so text is consumed before
4897 the nesting limit is exceeded.
4899 =item C<-p> destination: %s
4901 (F) An error occurred during the implicit output invoked by the C<-p>
4902 command-line switch. (This output goes to STDOUT unless you've
4903 redirected it with select().)
4905 =item Perl API version %s of %s does not match %s
4907 (F) The XS module in question was compiled against a different incompatible
4908 version of Perl than the one that has loaded the XS module.
4910 =item Perl folding rules are not up-to-date for 0x%X; please use the perlbug
4911 utility to report; in regex; marked by S<<-- HERE> in m/%s/
4913 (S regexp) You used a regular expression with case-insensitive matching,
4914 and there is a bug in Perl in which the built-in regular expression
4915 folding rules are not accurate. This may lead to incorrect results.
4916 Please report this as a bug to L<https://github.com/Perl/perl5/issues>.
4918 =item PerlIO layer ':win32' is experimental
4920 (S experimental::win32_perlio) The C<:win32> PerlIO layer is
4921 experimental. If you want to take the risk of using this layer,
4922 simply disable this warning:
4924 no warnings "experimental::win32_perlio";
4926 =item Perl_my_%s() not available
4928 (F) Your platform has very uncommon byte-order and integer size,
4929 so it was not possible to set up some or all fixed-width byte-order
4930 conversion functions. This is only a problem when you're using the
4931 '<' or '>' modifiers in (un)pack templates. See L<perlfunc/pack>.
4933 =item Perl %s required (did you mean %s?)--this is only %s, stopped
4935 (F) The code you are trying to run has asked for a newer version of
4936 Perl than you are running. Perhaps C<use 5.10> was written instead
4937 of C<use 5.010> or C<use v5.10>. Without the leading C<v>, the number is
4938 interpreted as a decimal, with every three digits after the
4939 decimal point representing a part of the version number. So 5.10
4940 is equivalent to v5.100.
4942 =item Perl %s required--this is only %s, stopped
4944 (F) The module in question uses features of a version of Perl more
4945 recent than the currently running version. How long has it been since
4946 you upgraded, anyway? See L<perlfunc/require>.
4948 =item PERL_SH_DIR too long
4950 (F) An error peculiar to OS/2. PERL_SH_DIR is the directory to find the
4951 C<sh>-shell in. See "PERL_SH_DIR" in L<perlos2>.
4953 =item PERL_SIGNALS illegal: "%s"
4955 (X) See L<perlrun/PERL_SIGNALS> for legal values.
4957 =item Perls since %s too modern--this is %s, stopped
4959 (F) The code you are trying to run claims it will not run
4960 on the version of Perl you are using because it is too new.
4961 Maybe the code needs to be updated, or maybe it is simply
4962 wrong and the version check should just be removed.
4964 =item perl: warning: Non hex character in '$ENV{PERL_HASH_SEED}', seed only partially set
4966 (S) PERL_HASH_SEED should match /^\s*(?:0x)?[0-9a-fA-F]+\s*\z/ but it
4967 contained a non hex character. This could mean you are not using the
4968 hash seed you think you are.
4970 =item perl: warning: Setting locale failed.
4972 (S) The whole warning message will look something like:
4974 perl: warning: Setting locale failed.
4975 perl: warning: Please check that your locale settings:
4978 are supported and installed on your system.
4979 perl: warning: Falling back to the standard locale ("C").
4981 Exactly what were the failed locale settings varies. In the above the
4982 settings were that the LC_ALL was "En_US" and the LANG had no value.
4983 This error means that Perl detected that you and/or your operating
4984 system supplier and/or system administrator have set up the so-called
4985 locale system but Perl could not use those settings. This was not
4986 dead serious, fortunately: there is a "default locale" called "C" that
4987 Perl can and will use, and the script will be run. Before you really
4988 fix the problem, however, you will get the same error message each
4989 time you run Perl. How to really fix the problem can be found in
4990 L<perllocale> section B<LOCALE PROBLEMS>.
4992 =item perl: warning: strange setting in '$ENV{PERL_PERTURB_KEYS}': '%s'
4994 (S) Perl was run with the environment variable PERL_PERTURB_KEYS defined
4995 but containing an unexpected value. The legal values of this setting
4998 Numeric | String | Result
4999 --------+---------------+-----------------------------------------
5000 0 | NO | Disables key traversal randomization
5001 1 | RANDOM | Enables full key traversal randomization
5002 2 | DETERMINISTIC | Enables repeatable key traversal
5005 Both numeric and string values are accepted, but note that string values are
5006 case sensitive. The default for this setting is "RANDOM" or 1.
5008 =item pid %x not a child
5010 (W exec) A warning peculiar to VMS. Waitpid() was asked to wait for a
5011 process which isn't a subprocess of the current process. While this is
5012 fine from VMS' perspective, it's probably not what you intended.
5014 =item 'P' must have an explicit size in unpack
5016 (F) The unpack format P must have an explicit size, not "*".
5018 =item POSIX class [:%s:] unknown in regex; marked by S<<-- HERE> in m/%s/
5020 (F) The class in the character class [: :] syntax is unknown. The S<<-- HERE>
5021 shows whereabouts in the regular expression the problem was discovered.
5022 Note that the POSIX character classes do B<not> have the C<is> prefix
5023 the corresponding C interfaces have: in other words, it's C<[[:print:]]>,
5024 not C<isprint>. See L<perlre>.
5026 =item POSIX getpgrp can't take an argument
5028 (F) Your system has POSIX getpgrp(), which takes no argument, unlike
5029 the BSD version, which takes a pid.
5031 =item POSIX syntax [%c %c] belongs inside character classes%s in regex; marked by
5032 S<<-- HERE> in m/%s/
5034 (W regexp) Perl thinks that you intended to write a POSIX character
5035 class, but didn't use enough brackets. These POSIX class constructs [:
5036 :], [= =], and [. .] go I<inside> character classes, the [] are part of
5037 the construct, for example: C<qr/[012[:alpha:]345]/>. What the regular
5038 expression pattern compiled to is probably not what you were intending.
5039 For example, C<qr/[:alpha:]/> compiles to a regular bracketed character
5040 class consisting of the four characters C<":">, C<"a">, C<"l">,
5041 C<"h">, and C<"p">. To specify the POSIX class, it should have been
5042 written C<qr/[[:alpha:]]/>.
5044 Note that [= =] and [. .] are not currently
5045 implemented; they are simply placeholders for future extensions and
5046 will cause fatal errors. The S<<-- HERE> shows whereabouts in the regular
5047 expression the problem was discovered. See L<perlre>.
5049 If the specification of the class was not completely valid, the message
5052 =item POSIX syntax [. .] is reserved for future extensions in regex; marked by
5053 S<<-- HERE> in m/%s/
5055 (F) Within regular expression character classes ([]) the syntax beginning
5056 with "[." and ending with ".]" is reserved for future extensions. If you
5057 need to represent those character sequences inside a regular expression
5058 character class, just quote the square brackets with the backslash: "\[."
5059 and ".\]". The S<<-- HERE> shows whereabouts in the regular expression the
5060 problem was discovered. See L<perlre>.
5062 =item POSIX syntax [= =] is reserved for future extensions in regex; marked by
5063 S<<-- HERE> in m/%s/
5065 (F) Within regular expression character classes ([]) the syntax beginning
5066 with "[=" and ending with "=]" is reserved for future extensions. If you
5067 need to represent those character sequences inside a regular expression
5068 character class, just quote the square brackets with the backslash: "\[="
5069 and "=\]". The S<<-- HERE> shows whereabouts in the regular expression the
5070 problem was discovered. See L<perlre>.
5072 =item Possible attempt to put comments in qw() list
5074 (W qw) qw() lists contain items separated by whitespace; as with literal
5075 strings, comment characters are not ignored, but are instead treated as
5076 literal data. (You may have used different delimiters than the
5077 parentheses shown here; braces are also frequently used.)
5079 You probably wrote something like this:
5086 when you should have written this:
5093 If you really want comments, build your list the
5094 old-fashioned way, with quotes and commas:
5098 'b', # another comment
5101 =item Possible attempt to separate words with commas
5103 (W qw) qw() lists contain items separated by whitespace; therefore
5104 commas aren't needed to separate the items. (You may have used
5105 different delimiters than the parentheses shown here; braces are also
5108 You probably wrote something like this:
5112 which puts literal commas into some of the list items. Write it without
5113 commas if you don't want them to appear in your data:
5117 =item Possible memory corruption: %s overflowed 3rd argument
5119 (F) An ioctl() or fcntl() returned more than Perl was bargaining for.
5120 Perl guesses a reasonable buffer size, but puts a sentinel byte at the
5121 end of the buffer just in case. This sentinel byte got clobbered, and
5122 Perl assumes that memory is now corrupted. See L<perlfunc/ioctl>.
5124 =item Possible precedence issue with control flow operator
5126 (W syntax) There is a possible problem with the mixing of a control
5127 flow operator (e.g. C<return>) and a low-precedence operator like
5130 sub { return $a or $b; }
5134 sub { (return $a) or $b; }
5136 Which is effectively just:
5140 Either use parentheses or the high-precedence variant of the operator.
5142 Note this may be also triggered for constructs like:
5146 =item Possible precedence problem on bitwise %s operator
5148 (W precedence) Your program uses a bitwise logical operator in conjunction
5149 with a numeric comparison operator, like this :
5151 if ($x & $y == 0) { ... }
5153 This expression is actually equivalent to C<$x & ($y == 0)>, due to the
5154 higher precedence of C<==>. This is probably not what you want. (If you
5155 really meant to write this, disable the warning, or, better, put the
5156 parentheses explicitly and write C<$x & ($y == 0)>).
5158 =item Possible unintended interpolation of $\ in regex
5160 (W ambiguous) You said something like C<m/$\/> in a regex.
5161 The regex C<m/foo$\s+bar/m> translates to: match the word 'foo', the output
5162 record separator (see L<perlvar/$\>) and the letter 's' (one time or more)
5163 followed by the word 'bar'.
5165 If this is what you intended then you can silence the warning by using
5166 C<m/${\}/> (for example: C<m/foo${\}s+bar/>).
5168 If instead you intended to match the word 'foo' at the end of the line
5169 followed by whitespace and the word 'bar' on the next line then you can use
5170 C<m/$(?)\/> (for example: C<m/foo$(?)\s+bar/>).
5172 =item Possible unintended interpolation of %s in string
5174 (W ambiguous) You said something like '@foo' in a double-quoted string
5175 but there was no array C<@foo> in scope at the time. If you wanted a
5176 literal @foo, then write it as \@foo; otherwise find out what happened
5177 to the array you apparently lost track of.
5179 =item Precedence problem: open %s should be open(%s)
5181 (S precedence) The old irregular construct
5185 is now misinterpreted as
5189 because of the strict regularization of Perl 5's grammar into unary and
5190 list operators. (The old open was a little of both.) You must put
5191 parentheses around the filehandle, or use the new "or" operator instead
5194 =item Premature end of script headers
5196 See L</500 Server error>.
5198 =item printf() on closed filehandle %s
5200 (W closed) The filehandle you're writing to got itself closed sometime
5201 before now. Check your control flow.
5203 =item print() on closed filehandle %s
5205 (W closed) The filehandle you're printing on got itself closed sometime
5206 before now. Check your control flow.
5208 =item Process terminated by SIG%s
5210 (W) This is a standard message issued by OS/2 applications, while *nix
5211 applications die in silence. It is considered a feature of the OS/2
5212 port. One can easily disable this by appropriate sighandlers, see
5213 L<perlipc/"Signals">. See also "Process terminated by SIGTERM/SIGINT"
5216 =item Prototype after '%c' for %s : %s
5218 (W illegalproto) A character follows % or @ in a prototype. This is
5219 useless, since % and @ gobble the rest of the subroutine arguments.
5221 =item Prototype mismatch: %s vs %s
5223 (S prototype) The subroutine being declared or defined had previously been
5224 declared or defined with a different function prototype.
5226 =item Prototype not terminated
5228 (F) You've omitted the closing parenthesis in a function prototype
5231 =item Prototype '%s' overridden by attribute 'prototype(%s)' in %s
5233 (W prototype) A prototype was declared in both the parentheses after
5234 the sub name and via the prototype attribute. The prototype in
5235 parentheses is useless, since it will be replaced by the prototype
5236 from the attribute before it's ever used.
5238 =item Quantifier follows nothing in regex; marked by S<<-- HERE> in m/%s/
5240 (F) You started a regular expression with a quantifier. Backslash it if
5241 you meant it literally. The S<<-- HERE> shows whereabouts in the regular
5242 expression the problem was discovered. See L<perlre>.
5244 =item Quantifier in {,} bigger than %d in regex; marked by S<<-- HERE> in m/%s/
5246 (F) There is currently a limit to the size of the min and max values of
5247 the {min,max} construct. The S<<-- HERE> shows whereabouts in the regular
5248 expression the problem was discovered. See L<perlre>.
5250 =item Quantifier {n,m} with n > m can't match in regex
5252 =item Quantifier {n,m} with n > m can't match in regex; marked by
5253 S<<-- HERE> in m/%s/
5255 (W regexp) Minima should be less than or equal to maxima. If you really
5256 want your regexp to match something 0 times, just put {0}.
5258 =item Quantifier unexpected on zero-length expression in regex m/%s/
5260 (W regexp) You applied a regular expression quantifier in a place where
5261 it makes no sense, such as on a zero-width assertion. Try putting the
5262 quantifier inside the assertion instead. For example, the way to match
5263 "abc" provided that it is followed by three repetitions of "xyz" is
5264 C</abc(?=(?:xyz){3})/>, not C</abc(?=xyz){3}/>.
5266 =item Range iterator outside integer range
5268 (F) One (or both) of the numeric arguments to the range operator ".."
5269 are outside the range which can be represented by integers internally.
5270 One possible workaround is to force Perl to use magical string increment
5271 by prepending "0" to your numbers.
5273 =item Ranges of ASCII printables should be some subset of "0-9", "A-Z", or
5274 "a-z" in regex; marked by S<<-- HERE> in m/%s/
5276 (W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
5278 Stricter rules help to find typos and other errors. Perhaps you didn't
5279 even intend a range here, if the C<"-"> was meant to be some other
5280 character, or should have been escaped (like C<"\-">). If you did
5281 intend a range, the one that was used is not portable between ASCII and
5282 EBCDIC platforms, and doesn't have an obvious meaning to a casual
5285 [3-7] # OK; Obvious and portable
5286 [d-g] # OK; Obvious and portable
5287 [A-Y] # OK; Obvious and portable
5288 [A-z] # WRONG; Not portable; not clear what is meant
5289 [a-Z] # WRONG; Not portable; not clear what is meant
5290 [%-.] # WRONG; Not portable; not clear what is meant
5291 [\x41-Z] # WRONG; Not portable; not obvious to non-geek
5293 (You can force portability by specifying a Unicode range, which means that
5294 the endpoints are specified by
5295 L<C<\N{...}>|perlrecharclass/Character Ranges>, but the meaning may
5296 still not be obvious.)
5297 The stricter rules require that ranges that start or stop with an ASCII
5298 character that is not a control have all their endpoints be the literal
5299 character, and not some escape sequence (like C<"\x41">), and the ranges
5300 must be all digits, or all uppercase letters, or all lowercase letters.
5302 =item Ranges of digits should be from the same group in regex; marked by
5303 S<<-- HERE> in m/%s/
5305 (W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
5307 Stricter rules help to find typos and other errors. You included a
5308 range, and at least one of the end points is a decimal digit. Under the
5309 stricter rules, when this happens, both end points should be digits in
5310 the same group of 10 consecutive digits.
5312 =item readdir() attempted on invalid dirhandle %s
5314 (W io) The dirhandle you're reading from is either closed or not really
5315 a dirhandle. Check your control flow.
5317 =item readline() on closed filehandle %s
5319 (W closed) The filehandle you're reading from got itself closed sometime
5320 before now. Check your control flow.
5322 =item readline() on unopened filehandle %s
5324 (W unopened) The filehandle you're reading from was never opened. Check your
5327 =item read() on closed filehandle %s
5329 (W closed) You tried to read from a closed filehandle.
5331 =item read() on unopened filehandle %s
5333 (W unopened) You tried to read from a filehandle that was never opened.
5335 =item Reallocation too large: %x
5337 (F) You can't allocate more than 64K on an MS-DOS machine.
5339 =item realloc() of freed memory ignored
5341 (S malloc) An internal routine called realloc() on something that had
5344 =item Recompile perl with B<-D>DEBUGGING to use B<-D> switch
5346 (S debugging) You can't use the B<-D> option unless the code to produce
5347 the desired output is compiled into Perl, which entails some overhead,
5348 which is why it's currently left out of your copy.
5350 =item Recursive call to Perl_load_module in PerlIO_find_layer
5352 (P) It is currently not permitted to load modules when creating
5353 a filehandle inside an %INC hook. This can happen with C<open my
5354 $fh, '<', \$scalar>, which implicitly loads PerlIO::scalar. Try
5355 loading PerlIO::scalar explicitly first.
5357 =item Recursive inheritance detected in package '%s'
5359 (F) While calculating the method resolution order (MRO) of a package, Perl
5360 believes it found an infinite loop in the C<@ISA> hierarchy. This is a
5361 crude check that bails out after 100 levels of C<@ISA> depth.
5363 =item Redundant argument in %s
5365 (W redundant) You called a function with more arguments than other
5366 arguments you supplied indicated would be needed. Currently only
5367 emitted when a printf-type format required fewer arguments than were
5368 supplied, but might be used in the future for e.g. L<perlfunc/pack>.
5370 =item refcnt_dec: fd %d%s
5372 =item refcnt: fd %d%s
5374 =item refcnt_inc: fd %d%s
5376 (P) Perl's I/O implementation failed an internal consistency check. If
5377 you see this message, something is very wrong.
5379 =item Reference found where even-sized list expected
5381 (W misc) You gave a single reference where Perl was expecting a list
5382 with an even number of elements (for assignment to a hash). This
5383 usually means that you used the anon hash constructor when you meant
5384 to use parens. In any case, a hash requires key/value B<pairs>.
5386 %hash = { one => 1, two => 2, }; # WRONG
5387 %hash = [ qw/ an anon array / ]; # WRONG
5388 %hash = ( one => 1, two => 2, ); # right
5389 %hash = qw( one 1 two 2 ); # also fine
5391 =item Reference is already weak
5393 (W misc) You have attempted to weaken a reference that is already weak.
5394 Doing so has no effect.
5396 =item Reference is not weak
5398 (W misc) You have attempted to unweaken a reference that is not weak.
5399 Doing so has no effect.
5401 =item Reference to invalid group 0 in regex; marked by S<<-- HERE> in m/%s/
5403 (F) You used C<\g0> or similar in a regular expression. You may refer
5404 to capturing parentheses only with strictly positive integers
5405 (normal backreferences) or with strictly negative integers (relative
5406 backreferences). Using 0 does not make sense.
5408 =item Reference to nonexistent group in regex; marked by S<<-- HERE> in
5411 (F) You used something like C<\7> in your regular expression, but there are
5412 not at least seven sets of capturing parentheses in the expression. If
5413 you wanted to have the character with ordinal 7 inserted into the regular
5414 expression, prepend zeroes to make it three digits long: C<\007>
5416 The S<<-- HERE> shows whereabouts in the regular expression the problem was
5419 =item Reference to nonexistent named group in regex; marked by S<<-- HERE>
5422 (F) You used something like C<\k'NAME'> or C<< \k<NAME> >> in your regular
5423 expression, but there is no corresponding named capturing parentheses
5424 such as C<(?'NAME'...)> or C<< (?<NAME>...) >>. Check if the name has been
5425 spelled correctly both in the backreference and the declaration.
5427 The S<<-- HERE> shows whereabouts in the regular expression the problem was
5430 =item Reference to nonexistent or unclosed group in regex; marked by
5431 S<<-- HERE> in m/%s/
5433 (F) You used something like C<\g{-7}> in your regular expression, but there
5434 are not at least seven sets of closed capturing parentheses in the
5435 expression before where the C<\g{-7}> was located.
5437 The S<<-- HERE> shows whereabouts in the regular expression the problem was
5440 =item regexp memory corruption
5442 (P) The regular expression engine got confused by what the regular
5443 expression compiler gave it.
5445 =item Regexp modifier "/%c" may appear a maximum of twice
5447 =item Regexp modifier "%c" may appear a maximum of twice in regex; marked
5448 by S<<-- HERE> in m/%s/
5450 (F) The regular expression pattern had too many occurrences
5451 of the specified modifier. Remove the extraneous ones.
5453 =item Regexp modifier "%c" may not appear after the "-" in regex; marked by <--
5456 (F) Turning off the given modifier has the side effect of turning on
5457 another one. Perl currently doesn't allow this. Reword the regular
5458 expression to use the modifier you want to turn on (and place it before
5459 the minus), instead of the one you want to turn off.
5461 =item Regexp modifier "/%c" may not appear twice
5463 =item Regexp modifier "%c" may not appear twice in regex; marked by <--
5466 (F) The regular expression pattern had too many occurrences
5467 of the specified modifier. Remove the extraneous ones.
5469 =item Regexp modifiers "/%c" and "/%c" are mutually exclusive
5471 =item Regexp modifiers "%c" and "%c" are mutually exclusive in regex;
5472 marked by S<<-- HERE> in m/%s/
5474 (F) The regular expression pattern had more than one of these
5475 mutually exclusive modifiers. Retain only the modifier that is
5476 supposed to be there.
5478 =item Regexp out of space in regex m/%s/
5480 (P) A "can't happen" error, because safemalloc() should have caught it
5483 =item Repeated format line will never terminate (~~ and @#)
5485 (F) Your format contains the ~~ repeat-until-blank sequence and a
5486 numeric field that will never go blank so that the repetition never
5487 terminates. You might use ^# instead. See L<perlform>.
5489 =item Replacement list is longer than search list
5491 (W misc) You have used a replacement list that is longer than the
5492 search list. So the additional elements in the replacement list
5495 =item '(*%s' requires a terminating ':' in regex; marked by <-- HERE in m/%s/
5497 (F) You used a construct that needs a colon and pattern argument.
5498 Supply these or check that you are using the right construct.
5500 =item '%s' resolved to '\o{%s}%d'
5502 As of Perl 5.32, this message is no longer generated. Instead, see
5503 L</Non-octal character '%c' terminates \o early. Resolved as "%s">.
5504 (W misc, regexp) You wrote something like C<\08>, or C<\179> in a
5505 double-quotish string. All but the last digit is treated as a single
5506 character, specified in octal. The last digit is the next character in
5507 the string. To tell Perl that this is indeed what you want, you can use
5508 the C<\o{ }> syntax, or use exactly three digits to specify the octal
5511 =item Reversed %s= operator
5513 (W syntax) You wrote your assignment operator backwards. The = must
5514 always come last, to avoid ambiguity with subsequent unary operators.
5516 =item rewinddir() attempted on invalid dirhandle %s
5518 (W io) The dirhandle you tried to do a rewinddir() on is either closed
5519 or not really a dirhandle. Check your control flow.
5521 =item Scalars leaked: %d
5523 (S internal) Something went wrong in Perl's internal bookkeeping
5524 of scalars: not all scalar variables were deallocated by the time
5525 Perl exited. What this usually indicates is a memory leak, which
5526 is of course bad, especially if the Perl program is intended to be
5529 =item Scalar value @%s[%s] better written as $%s[%s]
5531 (W syntax) You've used an array slice (indicated by @) to select a
5532 single element of an array. Generally it's better to ask for a scalar
5533 value (indicated by $). The difference is that C<$foo[&bar]> always
5534 behaves like a scalar, both when assigning to it and when evaluating its
5535 argument, while C<@foo[&bar]> behaves like a list when you assign to it,
5536 and provides a list context to its subscript, which can do weird things
5537 if you're expecting only one subscript.
5539 On the other hand, if you were actually hoping to treat the array
5540 element as a list, you need to look into how references work, because
5541 Perl will not magically convert between scalars and lists for you. See
5544 =item Scalar value @%s{%s} better written as $%s{%s}
5546 (W syntax) You've used a hash slice (indicated by @) to select a single
5547 element of a hash. Generally it's better to ask for a scalar value
5548 (indicated by $). The difference is that C<$foo{&bar}> always behaves
5549 like a scalar, both when assigning to it and when evaluating its
5550 argument, while C<@foo{&bar}> behaves like a list when you assign to it,
5551 and provides a list context to its subscript, which can do weird things
5552 if you're expecting only one subscript.
5554 On the other hand, if you were actually hoping to treat the hash element
5555 as a list, you need to look into how references work, because Perl will
5556 not magically convert between scalars and lists for you. See
5559 =item Search pattern not terminated
5561 (F) The lexer couldn't find the final delimiter of a // or m{}
5562 construct. Remember that bracketing delimiters count nesting level.
5563 Missing the leading C<$> from a variable C<$m> may cause this error.
5565 Note that since Perl 5.10.0 a // can also be the I<defined-or>
5566 construct, not just the empty search pattern. Therefore code written
5567 in Perl 5.10.0 or later that uses the // as the I<defined-or> can be
5568 misparsed by pre-5.10.0 Perls as a non-terminated search pattern.
5570 =item seekdir() attempted on invalid dirhandle %s
5572 (W io) The dirhandle you are doing a seekdir() on is either closed or not
5573 really a dirhandle. Check your control flow.
5575 =item %sseek() on unopened filehandle
5577 (W unopened) You tried to use the seek() or sysseek() function on a
5578 filehandle that was either never opened or has since been closed.
5580 =item select not implemented
5582 (F) This machine doesn't implement the select() system call.
5584 =item Self-ties of arrays and hashes are not supported
5586 (F) Self-ties are of arrays and hashes are not supported in
5587 the current implementation.
5589 =item Semicolon seems to be missing
5591 (W semicolon) A nearby syntax error was probably caused by a missing
5592 semicolon, or possibly some other missing operator, such as a comma.
5594 =item semi-panic: attempt to dup freed string
5596 (S internal) The internal newSVsv() routine was called to duplicate a
5597 scalar that had previously been marked as free.
5599 =item sem%s not implemented
5601 (F) You don't have System V semaphore IPC on your system.
5603 =item send() on closed socket %s
5605 (W closed) The socket you're sending to got itself closed sometime
5606 before now. Check your control flow.
5608 =item Sequence "\c{" invalid
5610 (F) These three characters may not appear in sequence in a
5611 double-quotish context. This message is raised only on non-ASCII
5612 platforms (a different error message is output on ASCII ones). If you
5613 were intending to specify a control character with this sequence, you'll
5614 have to use a different way to specify it.
5616 =item Sequence (? incomplete in regex; marked by S<<-- HERE> in m/%s/
5618 (F) A regular expression ended with an incomplete extension (?. The
5619 S<<-- HERE> shows whereabouts in the regular expression the problem was
5620 discovered. See L<perlre>.
5622 =item Sequence (?%c...) not implemented in regex; marked by S<<-- HERE> in
5625 (F) A proposed regular expression extension has the character reserved
5626 but has not yet been written. The S<<-- HERE> shows whereabouts in the
5627 regular expression the problem was discovered. See L<perlre>.
5629 =item Sequence (?%s...) not recognized in regex; marked by S<<-- HERE> in
5632 (F) You used a regular expression extension that doesn't make sense.
5633 The S<<-- HERE> shows whereabouts in the regular expression the problem was
5634 discovered. This may happen when using the C<(?^...)> construct to tell
5635 Perl to use the default regular expression modifiers, and you
5636 redundantly specify a default modifier. For other
5637 causes, see L<perlre>.
5639 =item Sequence (?#... not terminated in regex m/%s/
5641 (F) A regular expression comment must be terminated by a closing
5642 parenthesis. Embedded parentheses aren't allowed. See
5645 =item Sequence (?&... not terminated in regex; marked by S<<-- HERE> in
5648 (F) A named reference of the form C<(?&...)> was missing the final
5649 closing parenthesis after the name. The S<<-- HERE> shows whereabouts
5650 in the regular expression the problem was discovered.
5652 =item Sequence (?%c... not terminated in regex; marked by S<<-- HERE>
5655 (F) A named group of the form C<(?'...')> or C<< (?<...>) >> was missing the final
5656 closing quote or angle bracket. The S<<-- HERE> shows whereabouts in the
5657 regular expression the problem was discovered.
5659 =item Sequence (?(%c... not terminated in regex; marked by S<<-- HERE>
5662 (F) A named reference of the form C<(?('...')...)> or C<< (?(<...>)...) >> was
5663 missing the final closing quote or angle bracket after the name. The
5664 S<<-- HERE> shows whereabouts in the regular expression the problem was
5667 =item Sequence (?... not terminated in regex; marked by S<<-- HERE> in
5670 (F) There was no matching closing parenthesis for the '('. The
5671 S<<-- HERE> shows whereabouts in the regular expression the problem was
5674 =item Sequence \%s... not terminated in regex; marked by S<<-- HERE> in
5677 (F) The regular expression expects a mandatory argument following the escape
5678 sequence and this has been omitted or incorrectly written.
5680 =item Sequence (?{...}) not terminated with ')'
5682 (F) The end of the perl code contained within the {...} must be
5683 followed immediately by a ')'.
5685 =item Sequence (?PE<gt>... not terminated in regex; marked by S<<-- HERE> in m/%s/
5687 (F) A named reference of the form C<(?PE<gt>...)> was missing the final
5688 closing parenthesis after the name. The S<<-- HERE> shows whereabouts
5689 in the regular expression the problem was discovered.
5691 =item Sequence (?PE<lt>... not terminated in regex; marked by S<<-- HERE> in m/%s/
5693 (F) A named group of the form C<(?PE<lt>...E<gt>')> was missing the final
5694 closing angle bracket. The S<<-- HERE> shows whereabouts in the
5695 regular expression the problem was discovered.
5697 =item Sequence ?P=... not terminated in regex; marked by S<<-- HERE> in
5700 (F) A named reference of the form C<(?P=...)> was missing the final
5701 closing parenthesis after the name. The S<<-- HERE> shows whereabouts
5702 in the regular expression the problem was discovered.
5704 =item Sequence (?R) not terminated in regex m/%s/
5706 (F) An C<(?R)> or C<(?0)> sequence in a regular expression was missing the
5709 =item Z<>500 Server error
5711 (A) This is the error message generally seen in a browser window
5712 when trying to run a CGI program (including SSI) over the web. The
5713 actual error text varies widely from server to server. The most
5714 frequently-seen variants are "500 Server error", "Method (something)
5715 not permitted", "Document contains no data", "Premature end of script
5716 headers", and "Did not produce a valid header".
5718 B<This is a CGI error, not a Perl error>.
5720 You need to make sure your script is executable, is accessible by
5721 the user CGI is running the script under (which is probably not the
5722 user account you tested it under), does not rely on any environment
5723 variables (like PATH) from the user it isn't running under, and isn't
5724 in a location where the CGI server can't find it, basically, more or
5725 less. Please see the following for more information:
5727 https://www.perl.org/CGI_MetaFAQ.html
5728 http://www.htmlhelp.org/faq/cgifaq.html
5729 http://www.w3.org/Security/Faq/
5731 You should also look at L<perlfaq9>.
5733 =item setegid() not implemented
5735 (F) You tried to assign to C<$)>, and your operating system doesn't
5736 support the setegid() system call (or equivalent), or at least Configure
5739 =item seteuid() not implemented
5741 (F) You tried to assign to C<< $> >>, and your operating system doesn't
5742 support the seteuid() system call (or equivalent), or at least Configure
5745 =item setpgrp can't take arguments
5747 (F) Your system has the setpgrp() from BSD 4.2, which takes no
5748 arguments, unlike POSIX setpgid(), which takes a process ID and process
5751 =item setrgid() not implemented
5753 (F) You tried to assign to C<$(>, and your operating system doesn't
5754 support the setrgid() system call (or equivalent), or at least Configure
5757 =item setruid() not implemented
5759 (F) You tried to assign to C<$<>, and your operating system doesn't
5760 support the setruid() system call (or equivalent), or at least Configure
5763 =item setsockopt() on closed socket %s
5765 (W closed) You tried to set a socket option on a closed socket. Did you
5766 forget to check the return value of your socket() call? See
5767 L<perlfunc/setsockopt>.
5769 =item Setting $/ to a reference to %s is forbidden
5771 (F) You assigned a reference to a scalar to C<$/> where the referenced item is
5772 not a positive integer. In older perls this B<appeared> to work the same as
5773 setting it to C<undef> but was in fact internally different, less efficient
5774 and with very bad luck could have resulted in your file being split by a
5775 stringified form of the reference.
5777 In Perl 5.20.0 this was changed so that it would be B<exactly> the same as
5778 setting C<$/> to undef, with the exception that this warning would be thrown.
5780 You are recommended to change your code to set C<$/> to C<undef> explicitly if
5781 you wish to slurp the file. As of Perl 5.28 assigning C<$/> to a reference
5782 to an integer which isn't positive is a fatal error.
5784 =item Setting $/ to %s reference is forbidden
5786 (F) You tried to assign a reference to a non integer to C<$/>. In older
5787 Perls this would have behaved similarly to setting it to a reference to
5788 a positive integer, where the integer was the address of the reference.
5789 As of Perl 5.20.0 this is a fatal error, to allow future versions of Perl
5790 to use non-integer refs for more interesting purposes.
5792 =item shm%s not implemented
5794 (F) You don't have System V shared memory IPC on your system.
5796 =item !=~ should be !~
5798 (W syntax) The non-matching operator is !~, not !=~. !=~ will be
5799 interpreted as the != (numeric not equal) and ~ (1's complement)
5800 operators: probably not what you intended.
5802 =item /%s/ should probably be written as "%s"
5804 (W syntax) You have used a pattern where Perl expected to find a string,
5805 as in the first argument to C<join>. Perl will treat the true or false
5806 result of matching the pattern against $_ as the string, which is
5807 probably not what you had in mind.
5809 =item shutdown() on closed socket %s
5811 (W closed) You tried to do a shutdown on a closed socket. Seems a bit
5814 =item SIG%s handler "%s" not defined
5816 (W signal) The signal handler named in %SIG doesn't, in fact, exist.
5817 Perhaps you put it into the wrong package?
5819 =item Slab leaked from cv %p
5821 (S) If you see this message, then something is seriously wrong with the
5822 internal bookkeeping of op trees. An op tree needed to be freed after
5823 a compilation error, but could not be found, so it was leaked instead.
5825 =item sleep(%u) too large
5827 (W overflow) You called C<sleep> with a number that was larger than
5828 it can reliably handle and C<sleep> probably slept for less time than
5831 =item Slurpy parameter not last
5833 (F) In a subroutine signature, you put something after a slurpy (array or
5834 hash) parameter. The slurpy parameter takes all the available arguments,
5835 so there can't be any left to fill later parameters.
5837 =item Smart matching a non-overloaded object breaks encapsulation
5839 (F) You should not use the C<~~> operator on an object that does not
5840 overload it: Perl refuses to use the object's underlying structure
5841 for the smart match.
5843 =item Smartmatch is experimental
5845 (S experimental::smartmatch) This warning is emitted if you
5846 use the smartmatch (C<~~>) operator. This is currently an experimental
5847 feature, and its details are subject to change in future releases of
5848 Perl. Particularly, its current behavior is noticed for being
5849 unnecessarily complex and unintuitive, and is very likely to be
5852 =item Sorry, hash keys must be smaller than 2**31 bytes
5854 (F) You tried to create a hash containing a very large key, where "very
5855 large" means that it needs at least 2 gigabytes to store. Unfortunately,
5856 Perl doesn't yet handle such large hash keys. You should
5857 reconsider your design to avoid hashing such a long string directly.
5859 =item sort is now a reserved word
5861 (F) An ancient error message that almost nobody ever runs into anymore.
5862 But before sort was a keyword, people sometimes used it as a filehandle.
5864 =item Source filters apply only to byte streams
5866 (F) You tried to activate a source filter (usually by loading a
5867 source filter module) within a string passed to C<eval>. This is
5868 not permitted under the C<unicode_eval> feature. Consider using
5869 C<evalbytes> instead. See L<feature>.
5871 =item splice() offset past end of array
5873 (W misc) You attempted to specify an offset that was past the end of
5874 the array passed to splice(). Splicing will instead commence at the
5875 end of the array, rather than past it. If this isn't what you want,
5876 try explicitly pre-extending the array by assigning $#array = $offset.
5877 See L<perlfunc/splice>.
5881 (P) The split was looping infinitely. (Obviously, a split shouldn't
5882 iterate more times than there are characters of input, which is what
5883 happened.) See L<perlfunc/split>.
5885 =item Statement unlikely to be reached
5887 (W exec) You did an exec() with some statement after it other than a
5888 die(). This is almost always an error, because exec() never returns
5889 unless there was a failure. You probably wanted to use system()
5890 instead, which does return. To suppress this warning, put the exec() in
5893 =item "state" subroutine %s can't be in a package
5895 (F) Lexically scoped subroutines aren't in a package, so it doesn't make
5896 sense to try to declare one with a package qualifier on the front.
5898 =item "state %s" used in sort comparison
5900 (W syntax) The package variables $a and $b are used for sort comparisons.
5901 You used $a or $b in as an operand to the C<< <=> >> or C<cmp> operator inside a
5902 sort comparison block, and the variable had earlier been declared as a
5903 lexical variable. Either qualify the sort variable with the package
5904 name, or rename the lexical variable.
5906 =item "state" variable %s can't be in a package
5908 (F) Lexically scoped variables aren't in a package, so it doesn't make
5909 sense to try to declare one with a package qualifier on the front. Use
5910 local() if you want to localize a package variable.
5912 =item stat() on unopened filehandle %s
5914 (W unopened) You tried to use the stat() function on a filehandle that
5915 was either never opened or has since been closed.
5917 =item Strings with code points over 0xFF may not be mapped into in-memory file handles
5919 (W utf8) You tried to open a reference to a scalar for read or append
5920 where the scalar contained code points over 0xFF. In-memory files
5921 model on-disk files and can only contain bytes.
5923 =item Stub found while resolving method "%s" overloading "%s" in package "%s"
5925 (P) Overloading resolution over @ISA tree may be broken by importation
5926 stubs. Stubs should never be implicitly created, but explicit calls to
5927 C<can> may break this.
5929 =item Subroutine attributes must come before the signature
5931 (F) When subroutine signatures are enabled, any subroutine attributes must
5932 come before the signature. Note that this order was the opposite in
5933 versions 5.22..5.26. So:
5935 sub foo :lvalue ($a, $b) { ... } # 5.20 and 5.28 +
5936 sub foo ($a, $b) :lvalue { ... } # 5.22 .. 5.26
5938 =item Subroutine "&%s" is not available
5940 (W closure) During compilation, an inner named subroutine or eval is
5941 attempting to capture an outer lexical subroutine that is not currently
5942 available. This can happen for one of two reasons. First, the lexical
5943 subroutine may be declared in an outer anonymous subroutine that has
5944 not yet been created. (Remember that named subs are created at compile
5945 time, while anonymous subs are created at run-time.) For example,
5947 sub { my sub a {...} sub f { \&a } }
5949 At the time that f is created, it can't capture the current "a" sub,
5950 since the anonymous subroutine hasn't been created yet. Conversely, the
5951 following won't give a warning since the anonymous subroutine has by now
5952 been created and is live:
5954 sub { my sub a {...} eval 'sub f { \&a }' }->();
5956 The second situation is caused by an eval accessing a lexical subroutine
5957 that has gone out of scope, for example,
5965 Here, when the '\&a' in the eval is being compiled, f() is not currently
5966 being executed, so its &a is not available for capture.
5968 =item "%s" subroutine &%s masks earlier declaration in same %s
5970 (W shadow) A "my" or "state" subroutine has been redeclared in the
5971 current scope or statement, effectively eliminating all access to
5972 the previous instance. This is almost always a typographical error.
5973 Note that the earlier subroutine will still exist until the end of
5974 the scope or until all closure references to it are destroyed.
5976 =item Subroutine %s redefined
5978 (W redefine) You redefined a subroutine. To suppress this warning, say
5981 no warnings 'redefine';
5982 eval "sub name { ... }";
5985 =item Subroutine "%s" will not stay shared
5987 (W closure) An inner (nested) I<named> subroutine is referencing a "my"
5988 subroutine defined in an outer named subroutine.
5990 When the inner subroutine is called, it will see the value of the outer
5991 subroutine's lexical subroutine as it was before and during the *first*
5992 call to the outer subroutine; in this case, after the first call to the
5993 outer subroutine is complete, the inner and outer subroutines will no
5994 longer share a common value for the lexical subroutine. In other words,
5995 it will no longer be shared. This will especially make a difference
5996 if the lexical subroutines accesses lexical variables declared in its
5999 This problem can usually be solved by making the inner subroutine
6000 anonymous, using the C<sub {}> syntax. When inner anonymous subs that
6001 reference lexical subroutines in outer subroutines are created, they
6002 are automatically rebound to the current values of such lexical subs.
6004 =item Substitution loop
6006 (P) The substitution was looping infinitely. (Obviously, a substitution
6007 shouldn't iterate more times than there are characters of input, which
6008 is what happened.) See the discussion of substitution in
6009 L<perlop/"Regexp Quote-Like Operators">.
6011 =item Substitution pattern not terminated
6013 (F) The lexer couldn't find the interior delimiter of an s/// or s{}{}
6014 construct. Remember that bracketing delimiters count nesting level.
6015 Missing the leading C<$> from variable C<$s> may cause this error.
6017 =item Substitution replacement not terminated
6019 (F) The lexer couldn't find the final delimiter of an s/// or s{}{}
6020 construct. Remember that bracketing delimiters count nesting level.
6021 Missing the leading C<$> from variable C<$s> may cause this error.
6023 =item substr outside of string
6025 (W substr)(F) You tried to reference a substr() that pointed outside of
6026 a string. That is, the absolute value of the offset was larger than the
6027 length of the string. See L<perlfunc/substr>. This warning is fatal if
6028 substr is used in an lvalue context (as the left hand side of an
6029 assignment or as a subroutine argument for example).
6031 =item sv_upgrade from type %d down to type %d
6033 (P) Perl tried to force the upgrade of an SV to a type which was actually
6034 inferior to its current type.
6036 =item Switch (?(condition)... contains too many branches in regex; marked by
6037 S<<-- HERE> in m/%s/
6039 (F) A (?(condition)if-clause|else-clause) construct can have at most
6040 two branches (the if-clause and the else-clause). If you want one or
6041 both to contain alternation, such as using C<this|that|other>, enclose
6042 it in clustering parentheses:
6044 (?(condition)(?:this|that|other)|else-clause)
6046 The S<<-- HERE> shows whereabouts in the regular expression the problem
6047 was discovered. See L<perlre>.
6049 =item Switch condition not recognized in regex; marked by S<<-- HERE> in
6052 (F) The condition part of a (?(condition)if-clause|else-clause) construct
6053 is not known. The condition must be one of the following:
6055 (1) (2) ... true if 1st, 2nd, etc., capture matched
6056 (<NAME>) ('NAME') true if named capture matched
6057 (?=...) (?<=...) true if subpattern matches
6058 (?!...) (?<!...) true if subpattern fails to match
6059 (?{ CODE }) true if code returns a true value
6060 (R) true if evaluating inside recursion
6061 (R1) (R2) ... true if directly inside capture group 1, 2, etc.
6062 (R&NAME) true if directly inside named capture
6063 (DEFINE) always false; for defining named subpatterns
6065 The S<<-- HERE> shows whereabouts in the regular expression the problem was
6066 discovered. See L<perlre>.
6068 =item Switch (?(condition)... not terminated in regex; marked by
6069 S<<-- HERE> in m/%s/
6071 (F) You omitted to close a (?(condition)...) block somewhere
6072 in the pattern. Add a closing parenthesis in the appropriate
6073 position. See L<perlre>.
6075 =item switching effective %s is not implemented
6077 (F) While under the C<use filetest> pragma, we cannot switch the real
6078 and effective uids or gids.
6082 (F) Probably means you had a syntax error. Common reasons include:
6084 A keyword is misspelled.
6085 A semicolon is missing.
6087 An opening or closing parenthesis is missing.
6088 An opening or closing brace is missing.
6089 A closing quote is missing.
6091 Often there will be another error message associated with the syntax
6092 error giving more information. (Sometimes it helps to turn on B<-w>.)
6093 The error message itself often tells you where it was in the line when
6094 it decided to give up. Sometimes the actual error is several tokens
6095 before this, because Perl is good at understanding random input.
6096 Occasionally the line number may be misleading, and once in a blue moon
6097 the only way to figure out what's triggering the error is to call
6098 C<perl -c> repeatedly, chopping away half the program each time to see
6099 if the error went away. Sort of the cybernetic version of S<20 questions>.
6101 =item syntax error at line %d: '%s' unexpected
6103 (A) You've accidentally run your script through the Bourne shell instead
6104 of Perl. Check the #! line, or manually feed your script into Perl
6107 =item syntax error in file %s at line %d, next 2 tokens "%s"
6109 (F) This error is likely to occur if you run a perl5 script through
6110 a perl4 interpreter, especially if the next 2 tokens are "use strict"
6111 or "my $var" or "our $var".
6113 =item Syntax error in (?[...]) in regex; marked by <-- HERE in m/%s/
6115 (F) Perl could not figure out what you meant inside this construct; this
6116 notifies you that it is giving up trying.
6120 (F) The final summary message when a C<perl -c> succeeds.
6122 =item sysread() on closed filehandle %s
6124 (W closed) You tried to read from a closed filehandle.
6126 =item sysread() on unopened filehandle %s
6128 (W unopened) You tried to read from a filehandle that was never opened.
6130 =item System V %s is not implemented on this machine
6132 (F) You tried to do something with a function beginning with "sem",
6133 "shm", or "msg" but that System V IPC is not implemented in your
6134 machine. In some machines the functionality can exist but be
6135 unconfigured. Consult your system support.
6137 =item syswrite() on closed filehandle %s
6139 (W closed) The filehandle you're writing to got itself closed sometime
6140 before now. Check your control flow.
6142 =item C<-T> and C<-B> not implemented on filehandles
6144 (F) Perl can't peek at the stdio buffer of filehandles when it doesn't
6145 know about your kind of stdio. You'll have to use a filename instead.
6147 =item Target of goto is too deeply nested
6149 (F) You tried to use C<goto> to reach a label that was too deeply nested
6150 for Perl to reach. Perl is doing you a favor by refusing.
6152 =item telldir() attempted on invalid dirhandle %s
6154 (W io) The dirhandle you tried to telldir() is either closed or not really
6155 a dirhandle. Check your control flow.
6157 =item tell() on unopened filehandle
6159 (W unopened) You tried to use the tell() function on a filehandle that
6160 was either never opened or has since been closed.
6162 =item The crypt() function is unimplemented due to excessive paranoia.
6164 (F) Configure couldn't find the crypt() function on your machine,
6165 probably because your vendor didn't supply it, probably because they
6166 think the U.S. Government thinks it's a secret, or at least that they
6167 will continue to pretend that it is. And if you quote me on that, I
6170 =item The experimental declared_refs feature is not enabled
6172 (F) To declare references to variables, as in C<my \%x>, you must first enable
6175 no warnings "experimental::declared_refs";
6176 use feature "declared_refs";
6178 =item The %s function is unimplemented
6180 (F) The function indicated isn't implemented on this architecture,
6181 according to the probings of Configure.
6183 =item The private_use feature is experimental
6185 (S experimental::private_use) This feature is actually a hook for future
6188 =item The regex_sets feature is experimental
6190 (S experimental::regex_sets) This warning is emitted if you
6191 use the syntax S<C<(?[ ])>> in a regular expression.
6192 The details of this feature are subject to change.
6193 If you want to use it, but know that in doing so you
6194 are taking the risk of using an experimental feature which may
6195 change in a future Perl version, you can do this to silence the
6198 no warnings "experimental::regex_sets";
6200 =item The signatures feature is experimental
6202 (S experimental::signatures) This warning is emitted if you unwrap a
6203 subroutine's arguments using a signature. Simply suppress the warning
6204 if you want to use the feature, but know that in doing so you are taking
6205 the risk of using an experimental feature which may change or be removed
6206 in a future Perl version:
6208 no warnings "experimental::signatures";
6209 use feature "signatures";
6210 sub foo ($left, $right) { ... }
6212 =item The stat preceding %s wasn't an lstat
6214 (F) It makes no sense to test the current stat buffer for symbolic
6215 linkhood if the last stat that wrote to the stat buffer already went
6216 past the symlink to get to the real file. Use an actual filename
6219 =item The Unicode property wildcards feature is experimental
6221 (S experimental::uniprop_wildcards) This feature is experimental
6222 and its behavior may in any future release of perl. See
6223 L<perlunicode/Wildcards in Property Values>.
6225 =item The 'unique' attribute may only be applied to 'our' variables
6227 (F) This attribute was never supported on C<my> or C<sub> declarations.
6229 =item This Perl can't reset CRTL environ elements (%s)
6231 =item This Perl can't set CRTL environ elements (%s=%s)
6233 (W internal) Warnings peculiar to VMS. You tried to change or delete an
6234 element of the CRTL's internal environ array, but your copy of Perl
6235 wasn't built with a CRTL that contained the setenv() function. You'll
6236 need to rebuild Perl with a CRTL that does, or redefine
6237 F<PERL_ENV_TABLES> (see L<perlvms>) so that the environ array isn't the
6238 target of the change to
6239 %ENV which produced the warning.
6241 =item This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().
6243 (F) Something has attempted to use an internal API call which
6244 depends on Perl being compiled with the default support for randomized hash
6245 key traversal, but this Perl has been compiled without it. You should
6246 report this warning to the relevant upstream party, or recompile perl
6247 with default options.
6249 =item This use of my() in false conditional is no longer allowed
6251 (F) You used a declaration similar to C<my $x if 0>. There
6252 has been a long-standing bug in Perl that causes a lexical variable
6253 not to be cleared at scope exit when its declaration includes a false
6254 conditional. Some people have exploited this bug to achieve a kind of
6255 static variable. Since we intend to fix this bug, we don't want people
6256 relying on this behavior. You can achieve a similar static effect by
6257 declaring the variable in a separate block outside the function, eg
6259 sub f { my $x if 0; return $x++ }
6263 { my $x; sub f { return $x++ } }
6265 Beginning with perl 5.10.0, you can also use C<state> variables to have
6266 lexicals that are initialized only once (see L<feature>):
6268 sub f { state $x; return $x++ }
6270 This use of C<my()> in a false conditional was deprecated beginning in
6271 Perl 5.10 and became a fatal error in Perl 5.30.
6273 =item times not implemented
6275 (F) Your version of the C library apparently doesn't do times(). I
6276 suspect you're not running on Unix.
6278 =item "-T" is on the #! line, it must also be used on the command line
6280 (X) The #! line (or local equivalent) in a Perl script contains
6281 the B<-T> option (or the B<-t> option), but Perl was not invoked with
6282 B<-T> in its command line. This is an error because, by the time
6283 Perl discovers a B<-T> in a script, it's too late to properly taint
6284 everything from the environment. So Perl gives up.
6286 If the Perl script is being executed as a command using the #!
6287 mechanism (or its local equivalent), this error can usually be
6288 fixed by editing the #! line so that the B<-%c> option is a part of
6289 Perl's first argument: e.g. change C<perl -n -%c> to C<perl -%c -n>.
6291 If the Perl script is being executed as C<perl scriptname>, then the
6292 B<-%c> option must appear on the command line: C<perl -%c scriptname>.
6294 =item To%s: illegal mapping '%s'
6296 (F) You tried to define a customized To-mapping for lc(), lcfirst,
6297 uc(), or ucfirst() (or their string-inlined versions), but you
6298 specified an illegal mapping.
6299 See L<perlunicode/"User-Defined Character Properties">.
6301 =item Too deeply nested ()-groups
6303 (F) Your template contains ()-groups with a ridiculously deep nesting level.
6305 =item Too few args to syscall
6307 (F) There has to be at least one argument to syscall() to specify the
6308 system call to call, silly dilly.
6310 =item Too few arguments for subroutine '%s'
6312 (F) A subroutine using a signature fewer arguments than required by the
6313 signature. The caller of the subroutine is presumably at fault.
6315 The message attempts to include the name of the called subroutine. If
6316 the subroutine has been aliased, the subroutine's original name will be
6317 shown, regardless of what name the caller used.
6319 =item Too late for "-%s" option
6321 (X) The #! line (or local equivalent) in a Perl script contains the
6322 B<-M>, B<-m> or B<-C> option.
6324 In the case of B<-M> and B<-m>, this is an error because those options
6325 are not intended for use inside scripts. Use the C<use> pragma instead.
6327 The B<-C> option only works if it is specified on the command line as
6328 well (with the same sequence of letters or numbers following). Either
6329 specify this option on the command line, or, if your system supports
6330 it, make your script executable and run it directly instead of passing
6333 =item Too late to run %s block
6335 (W void) A CHECK or INIT block is being defined during run time proper,
6336 when the opportunity to run them has already passed. Perhaps you are
6337 loading a file with C<require> or C<do> when you should be using C<use>
6338 instead. Or perhaps you should put the C<require> or C<do> inside a
6341 =item Too many args to syscall
6343 (F) Perl supports a maximum of only 14 args to syscall().
6345 =item Too many arguments for %s
6347 (F) The function requires fewer arguments than you specified.
6349 =item Too many arguments for subroutine '%s'
6351 (F) A subroutine using a signature received more arguments than permitted
6352 by the signature. The caller of the subroutine is presumably at fault.
6354 The message attempts to include the name of the called subroutine. If the
6355 subroutine has been aliased, the subroutine's original name will be shown,
6356 regardless of what name the caller used.
6358 =item Too many nested open parens in regex; marked by <-- HERE in m/%s/
6360 (F) You have exceeded the number of open C<"("> parentheses that haven't
6361 been matched by corresponding closing ones. This limit prevents eating
6362 up too much memory. It is initially set to 1000, but may be changed by
6363 setting C<${^RE_COMPILE_RECURSION_LIMIT}> to some other value. This may
6364 need to be done in a BEGIN block before the regular expression pattern
6369 (A) You've accidentally run your script through B<csh> instead of Perl.
6370 Check the #! line, or manually feed your script into Perl yourself.
6374 (A) You've accidentally run your script through B<csh> instead of Perl.
6375 Check the #! line, or manually feed your script into Perl yourself.
6377 =item Trailing \ in regex m/%s/
6379 (F) The regular expression ends with an unbackslashed backslash.
6380 Backslash it. See L<perlre>.
6382 =item Transliteration pattern not terminated
6384 (F) The lexer couldn't find the interior delimiter of a tr/// or tr[][]
6385 or y/// or y[][] construct. Missing the leading C<$> from variables
6386 C<$tr> or C<$y> may cause this error.
6388 =item Transliteration replacement not terminated
6390 (F) The lexer couldn't find the final delimiter of a tr///, tr[][],
6391 y/// or y[][] construct.
6393 =item '%s' trapped by operation mask
6395 (F) You tried to use an operator from a Safe compartment in which it's
6396 disallowed. See L<Safe>.
6398 =item truncate not implemented
6400 (F) Your machine doesn't implement a file truncation mechanism that
6401 Configure knows about.
6403 =item Type of arg %d to &CORE::%s must be %s
6405 (F) The subroutine in question in the CORE package requires its argument
6406 to be a hard reference to data of the specified type. Overloading is
6407 ignored, so a reference to an object that is not the specified type, but
6408 nonetheless has overloading to handle it, will still not be accepted.
6410 =item Type of arg %d to %s must be %s (not %s)
6412 (F) This function requires the argument in that position to be of a
6413 certain type. Arrays must be @NAME or C<@{EXPR}>. Hashes must be
6414 %NAME or C<%{EXPR}>. No implicit dereferencing is allowed--use the
6415 {EXPR} forms as an explicit dereference. See L<perlref>.
6417 =item umask not implemented
6419 (F) Your machine doesn't implement the umask function and you tried to
6420 use it to restrict permissions for yourself (EXPR & 0700).
6422 =item Unbalanced context: %d more PUSHes than POPs
6424 (S internal) The exit code detected an internal inconsistency in how
6425 many execution contexts were entered and left.
6427 =item Unbalanced saves: %d more saves than restores
6429 (S internal) The exit code detected an internal inconsistency in how
6430 many values were temporarily localized.
6432 =item Unbalanced scopes: %d more ENTERs than LEAVEs
6434 (S internal) The exit code detected an internal inconsistency in how
6435 many blocks were entered and left.
6437 =item Unbalanced string table refcount: (%d) for "%s"
6439 (S internal) On exit, Perl found some strings remaining in the shared
6440 string table used for copy on write and for hash keys. The entries
6441 should have been freed, so this indicates a bug somewhere.
6443 =item Unbalanced tmps: %d more allocs than frees
6445 (S internal) The exit code detected an internal inconsistency in how
6446 many mortal scalars were allocated and freed.
6448 =item Undefined format "%s" called
6450 (F) The format indicated doesn't seem to exist. Perhaps it's really in
6451 another package? See L<perlform>.
6453 =item Undefined sort subroutine "%s" called
6455 (F) The sort comparison routine specified doesn't seem to exist.
6456 Perhaps it's in a different package? See L<perlfunc/sort>.
6458 =item Undefined subroutine &%s called
6460 (F) The subroutine indicated hasn't been defined, or if it was, it has
6461 since been undefined.
6463 =item Undefined subroutine called
6465 (F) The anonymous subroutine you're trying to call hasn't been defined,
6466 or if it was, it has since been undefined.
6468 =item Undefined subroutine in sort
6470 (F) The sort comparison routine specified is declared but doesn't seem
6471 to have been defined yet. See L<perlfunc/sort>.
6473 =item Undefined top format "%s" called
6475 (F) The format indicated doesn't seem to exist. Perhaps it's really in
6476 another package? See L<perlform>.
6478 =item Undefined value assigned to typeglob
6480 (W misc) An undefined value was assigned to a typeglob, a la
6481 C<*foo = undef>. This does nothing. It's possible that you really mean
6484 =item %s: Undefined variable
6486 (A) You've accidentally run your script through B<csh> instead of Perl.
6487 Check the #! line, or manually feed your script into Perl yourself.
6489 =item Unescaped left brace in regex is illegal here in regex;
6490 marked by S<<-- HERE> in m/%s/
6492 (F) The simple rule to remember, if you want to
6493 match a literal C<"{"> character (U+007B C<LEFT CURLY BRACKET>) in a
6494 regular expression pattern, is to escape each literal instance of it in
6495 some way. Generally easiest is to precede it with a backslash, like
6496 C<"\{"> or enclose it in square brackets (C<"[{]">). If the pattern
6497 delimiters are also braces, any matching right brace (C<"}">) should
6498 also be escaped to avoid confusing the parser, for example,
6502 Forcing literal C<"{"> characters to be escaped enables the Perl
6503 language to be extended in various ways in future releases. To avoid
6504 needlessly breaking existing code, the restriction is not enforced in
6505 contexts where there are unlikely to ever be extensions that could
6506 conflict with the use there of C<"{"> as a literal. Those that are
6507 not potentially ambiguous do not warn; those that are do raise a
6508 non-deprecation warning.
6510 The contexts where no warnings or errors are raised are:
6516 as the first character in a pattern, or following C<"^"> indicating to
6517 anchor the match to the beginning of a line.
6521 as the first character following a C<"|"> indicating alternation.
6525 as the first character in a parenthesized grouping like
6532 as the first character following a quantifier
6539 The text of the message above is mostly duplicated below (with changes)
6540 to allow splain (and 'use diagnostics') to work. Since one is fatal,
6541 and one not, they can't be combined as one message. Perhaps perldiag
6542 could be enhanced to handle this case.
6544 =item Unescaped left brace in regex is passed through in regex; marked by S<<-- HERE> in m/%s/
6546 (W regexp) The simple rule to remember, if you want to
6547 match a literal C<"{"> character (U+007B C<LEFT CURLY BRACKET>) in a
6548 regular expression pattern, is to escape each literal instance of it in
6549 some way. Generally easiest is to precede it with a backslash, like
6550 C<"\{"> or enclose it in square brackets (C<"[{]">). If the pattern
6551 delimiters are also braces, any matching right brace (C<"}">) should
6552 also be escaped to avoid confusing the parser, for example,
6556 Forcing literal C<"{"> characters to be escaped enables the Perl
6557 language to be extended in various ways in future releases. To avoid
6558 needlessly breaking existing code, the restriction is not enforced in
6559 contexts where there are unlikely to ever be extensions that could
6560 conflict with the use there of C<"{"> as a literal. Those that are
6561 not potentially ambiguous do not warn; those that are raise this
6562 warning. This makes sure that an inadvertent typo doesn't silently
6563 cause the pattern to compile to something unintended.
6565 The contexts where no warnings or errors are raised are:
6571 as the first character in a pattern, or following C<"^"> indicating to
6572 anchor the match to the beginning of a line.
6576 as the first character following a C<"|"> indicating alternation.
6580 as the first character in a parenthesized grouping like
6587 as the first character following a quantifier
6593 =item Unescaped literal '%c' in regex; marked by <-- HERE in m/%s/
6595 (W regexp) (only under C<S<use re 'strict'>>)
6597 Within the scope of C<S<use re 'strict'>> in a regular expression
6598 pattern, you included an unescaped C<}> or C<]> which was interpreted
6599 literally. These two characters are sometimes metacharacters, and
6600 sometimes literals, depending on what precedes them in the
6601 pattern. This is unlike the similar C<)> which is always a
6602 metacharacter unless escaped.
6604 This action at a distance, perhaps a large distance, can lead to Perl
6605 silently misinterpreting what you meant, so when you specify that you
6606 want extra checking by C<S<use re 'strict'>>, this warning is generated.
6607 If you meant the character as a literal, simply confirm that to Perl by
6608 preceding the character with a backslash, or make it into a bracketed
6609 character class (like C<[}]>). If you meant it as closing a
6610 corresponding C<[> or C<{>, you'll need to look back through the pattern
6611 to find out why that isn't happening.
6613 =item unexec of %s into %s failed!
6615 (F) The unexec() routine failed for some reason. See your local FSF
6616 representative, who probably put it there in the first place.
6618 =item Unexpected binary operator '%c' with no preceding operand in regex;
6619 marked by S<<-- HERE> in m/%s/
6621 (F) You had something like this:
6625 where the C<"|"> is a binary operator with an operand on the right, but
6626 no operand on the left.
6628 =item Unexpected character in regex; marked by S<<-- HERE> in m/%s/
6630 (F) You had something like this:
6634 Within C<(?[ ])>, no literal characters are allowed unless they are
6635 within an inner pair of square brackets, like
6639 Another possibility is that you forgot a backslash. Perl isn't smart
6640 enough to figure out what you really meant.
6642 =item Unexpected constant lvalue entersub entry via type/targ %d:%d
6644 (P) When compiling a subroutine call in lvalue context, Perl failed an
6645 internal consistency check. It encountered a malformed op tree.
6647 =item Unexpected exit %u
6649 (S) exit() was called or the script otherwise finished gracefully when
6650 C<PERL_EXIT_WARN> was set in C<PL_exit_flags>.
6652 =item Unexpected exit failure %d
6654 (S) An uncaught die() was called when C<PERL_EXIT_WARN> was set in
6657 =item Unexpected ')' in regex; marked by S<<-- HERE> in m/%s/
6659 (F) You had something like this:
6661 (?[ ( \p{Digit} + ) ])
6663 The C<")"> is out-of-place. Something apparently was supposed to
6664 be combined with the digits, or the C<"+"> shouldn't be there, or
6665 something like that. Perl can't figure out what was intended.
6667 =item Unexpected ']' with no following ')' in (?[... in regex; marked by
6670 (F) While parsing an extended character class a ']' character was
6671 encountered at a point in the definition where the only legal use of
6672 ']' is to close the character class definition as part of a '])', you
6673 may have forgotten the close paren, or otherwise confused the parser.
6675 =item Unexpected '(' with no preceding operator in regex; marked by
6676 S<<-- HERE> in m/%s/
6678 (F) You had something like this:
6680 (?[ \p{Digit} ( \p{Lao} + \p{Thai} ) ])
6682 There should be an operator before the C<"(">, as there's
6683 no indication as to how the digits are to be combined
6684 with the characters in the Lao and Thai scripts.
6686 =item Unicode non-character U+%X is not recommended for open interchange
6688 (S nonchar) Certain codepoints, such as U+FFFE and U+FFFF, are
6689 defined by the Unicode standard to be non-characters. Those
6690 are legal codepoints, but are reserved for internal use; so,
6691 applications shouldn't attempt to exchange them. An application
6692 may not be expecting any of these characters at all, and receiving
6693 them may lead to bugs. If you know what you are doing you can
6694 turn off this warning by C<no warnings 'nonchar';>.
6696 This is not really a "severe" error, but it is supposed to be
6697 raised by default even if warnings are not enabled, and currently
6698 the only way to do that in Perl is to mark it as serious.
6700 =item Unicode property wildcard not terminated
6702 (F) A Unicode property wildcard looks like a delimited regular
6703 expression pattern (all within the braces of the enclosing C<\p{...}>.
6704 The closing delimtter to match the opening one was not found. If the
6705 opening one is escaped by preceding it with a backslash, the closing one
6706 must also be so escaped.
6708 =item Unicode string properties are not implemented in (?[...]) in
6709 regex; marked by <-- HERE in m/%s/
6711 (F) A Unicode string property is one which expands to a sequence of
6712 multiple characters. An example is C<\p{name=KATAKANA LETTER AINU P}>,
6713 which is comprised of the sequence C<\N{KATAKANA LETTER SMALL H}>
6714 followed by C<\N{COMBINING KATAKANA-HIRAGANA SEMI-VOICED SOUND MARK}>.
6715 Extended character classes, C<(?[...])> currently cannot handle these.
6717 =item Unicode surrogate U+%X is illegal in UTF-8
6719 (S surrogate) You had a UTF-16 surrogate in a context where they are
6720 not considered acceptable. These code points, between U+D800 and
6721 U+DFFF (inclusive), are used by Unicode only for UTF-16. However, Perl
6722 internally allows all unsigned integer code points (up to the size limit
6723 available on your platform), including surrogates. But these can cause
6724 problems when being input or output, which is likely where this message
6725 came from. If you really really know what you are doing you can turn
6726 off this warning by C<no warnings 'surrogate';>.
6728 =item Unknown charname '%s'
6730 (F) The name you used inside C<\N{}> is unknown to Perl. Check the
6731 spelling. You can say C<use charnames ":loose"> to not have to be
6732 so precise about spaces, hyphens, and capitalization on standard Unicode
6733 names. (Any custom aliases that have been created must be specified
6734 exactly, regardless of whether C<:loose> is used or not.) This error may
6735 also happen if the C<\N{}> is not in the scope of the corresponding
6736 C<S<use charnames>>.
6738 =item Unknown '(*...)' construct '%s' in regex; marked by <-- HERE in m/%s/
6740 (F) The C<(*> was followed by something that the regular expression
6741 compiler does not recognize. Check your spelling.
6745 (P) Perl was about to print an error message in C<$@>, but the C<$@> variable
6746 did not exist, even after an attempt to create it.
6748 =item Unknown locale category %d; can't set it to %s
6750 (W locale) You used a locale category that perl doesn't recognize, so it
6751 cannot carry out your request. Check that you are using a valid
6752 category. If so, see L<perllocale/Multi-threaded> for advice on
6753 reporting this as a bug, and for modifying perl locally to accommodate
6756 =item Unknown open() mode '%s'
6758 (F) The second argument of 3-argument open() is not among the list
6759 of valid modes: C<< < >>, C<< > >>, C<<< >> >>>, C<< +< >>,
6760 C<< +> >>, C<<< +>> >>>, C<-|>, C<|->, C<< <& >>, C<< >& >>.
6762 =item Unknown PerlIO layer "%s"
6764 (W layer) An attempt was made to push an unknown layer onto the Perl I/O
6765 system. (Layers take care of transforming data between external and
6766 internal representations.) Note that some layers, such as C<mmap>,
6767 are not supported in all environments. If your program didn't
6768 explicitly request the failing operation, it may be the result of the
6769 value of the environment variable PERLIO.
6771 =item Unknown process %x sent message to prime_env_iter: %s
6773 (P) An error peculiar to VMS. Perl was reading values for %ENV before
6774 iterating over it, and someone else stuck a message in the stream of
6775 data Perl expected. Someone's very confused, or perhaps trying to
6776 subvert Perl's population of %ENV for nefarious purposes.
6778 =item Unknown regexp modifier "/%s"
6780 (F) Alphanumerics immediately following the closing delimiter
6781 of a regular expression pattern are interpreted by Perl as modifier
6782 flags for the regex. One of the ones you specified is invalid. One way
6783 this can happen is if you didn't put in white space between the end of
6784 the regex and a following alphanumeric operator:
6786 if ($a =~ /foo/and $bar == 3) { ... }
6788 The C<"a"> is a valid modifier flag, but the C<"n"> is not, and raises
6789 this error. Likely what was meant instead was:
6791 if ($a =~ /foo/ and $bar == 3) { ... }
6793 =item Unknown "re" subpragma '%s' (known ones are: %s)
6795 (W) You tried to use an unknown subpragma of the "re" pragma.
6797 =item Unknown switch condition (?(...)) in regex; marked by S<<-- HERE> in
6800 (F) The condition part of a (?(condition)if-clause|else-clause) construct
6801 is not known. The condition must be one of the following:
6803 (1) (2) ... true if 1st, 2nd, etc., capture matched
6804 (<NAME>) ('NAME') true if named capture matched
6805 (?=...) (?<=...) true if subpattern matches
6806 (*pla:...) (*plb:...) true if subpattern matches; also
6807 (*positive_lookahead:...)
6808 (*positive_lookbehind:...)
6809 (*nla:...) (*nlb:...) true if subpattern fails to match; also
6810 (*negative_lookahead:...)
6811 (*negative_lookbehind:...)
6812 (?{ CODE }) true if code returns a true value
6813 (R) true if evaluating inside recursion
6814 (R1) (R2) ... true if directly inside capture group 1, 2,
6816 (R&NAME) true if directly inside named capture
6817 (DEFINE) always false; for defining named subpatterns
6819 The S<<-- HERE> shows whereabouts in the regular expression the problem was
6820 discovered. See L<perlre>.
6822 =item Unknown Unicode option letter '%c'
6824 (F) You specified an unknown Unicode option. See
6825 L<perlrun|perlrun/-C [numberE<sol>list]> documentation of the C<-C> switch
6826 for the list of known options.
6828 =item Unknown Unicode option value %d
6830 (F) You specified an unknown Unicode option. See
6831 L<perlrun|perlrun/-C [numberE<sol>list]> documentation of the C<-C> switch
6832 for the list of known options.
6834 =item Unknown verb pattern '%s' in regex; marked by S<<-- HERE> in m/%s/
6836 (F) You either made a typo or have incorrectly put a C<*> quantifier
6837 after an open brace in your pattern. Check the pattern and review
6838 L<perlre> for details on legal verb patterns.
6840 =item Unknown warnings category '%s'
6842 (F) An error issued by the C<warnings> pragma. You specified a warnings
6843 category that is unknown to perl at this point.
6845 Note that if you want to enable a warnings category registered by a
6846 module (e.g. C<use warnings 'File::Find'>), you must have loaded this
6849 =item Unmatched [ in regex; marked by S<<-- HERE> in m/%s/
6851 (F) The brackets around a character class must match. If you wish to
6852 include a closing bracket in a character class, backslash it or put it
6853 first. The S<<-- HERE> shows whereabouts in the regular expression the
6854 problem was discovered. See L<perlre>.
6856 =item Unmatched ( in regex; marked by S<<-- HERE> in m/%s/
6858 =item Unmatched ) in regex; marked by S<<-- HERE> in m/%s/
6860 (F) Unbackslashed parentheses must always be balanced in regular
6861 expressions. If you're a vi user, the % key is valuable for finding
6862 the matching parenthesis. The S<<-- HERE> shows whereabouts in the
6863 regular expression the problem was discovered. See L<perlre>.
6865 =item Unmatched right %s bracket
6867 (F) The lexer counted more closing curly or square brackets than opening
6868 ones, so you're probably missing a matching opening bracket. As a
6869 general rule, you'll find the missing one (so to speak) near the place
6870 you were last editing.
6872 =item Unquoted string "%s" may clash with future reserved word
6874 (W reserved) You used a bareword that might someday be claimed as a
6875 reserved word. It's best to put such a word in quotes, or capitalize it
6876 somehow, or insert an underbar into it. You might also declare it as a
6879 =item Unrecognized character %s; marked by S<<-- HERE> after %s near column
6882 (F) The Perl parser has no idea what to do with the specified character
6883 in your Perl script (or eval) near the specified column. Perhaps you
6884 tried to run a compressed script, a binary program, or a directory as
6887 =item Unrecognized escape \%c in character class in regex; marked by
6888 S<<-- HERE> in m/%s/
6890 (F) You used a backslash-character combination which is not
6891 recognized by Perl inside character classes. This is a fatal
6892 error when the character class is used within C<(?[ ])>.
6894 =item Unrecognized escape \%c in character class passed through in regex;
6895 marked by S<<-- HERE> in m/%s/
6897 (W regexp) You used a backslash-character combination which is not
6898 recognized by Perl inside character classes. The character was
6899 understood literally, but this may change in a future version of Perl.
6900 The S<<-- HERE> shows whereabouts in the regular expression the
6901 escape was discovered.
6903 =item Unrecognized escape \%c passed through
6905 (W misc) You used a backslash-character combination which is not
6906 recognized by Perl. The character was understood literally, but this may
6907 change in a future version of Perl.
6909 =item Unrecognized escape \%s passed through in regex; marked by
6910 S<<-- HERE> in m/%s/
6912 (W regexp) You used a backslash-character combination which is not
6913 recognized by Perl. The character(s) were understood literally, but
6914 this may change in a future version of Perl. The S<<-- HERE> shows
6915 whereabouts in the regular expression the escape was discovered.
6917 =item Unrecognized signal name "%s"
6919 (F) You specified a signal name to the kill() function that was not
6920 recognized. Say C<kill -l> in your shell to see the valid signal names
6923 =item Unrecognized switch: -%s (-h will show valid options)
6925 (F) You specified an illegal option to Perl. Don't do that. (If you
6926 think you didn't do that, check the #! line to see if it's supplying the
6927 bad switch on your behalf.)
6929 =item Unsuccessful %s on filename containing newline
6931 (W newline) A file operation was attempted on a filename, and that
6932 operation failed, PROBABLY because the filename contained a newline,
6933 PROBABLY because you forgot to chomp() it off. See L<perlfunc/chomp>.
6935 =item Unsupported directory function "%s" called
6937 (F) Your machine doesn't support opendir() and readdir().
6939 =item Unsupported function %s
6941 (F) This machine doesn't implement the indicated function, apparently.
6942 At least, Configure doesn't think so.
6944 =item Unsupported function fork
6946 (F) Your version of executable does not support forking.
6948 Note that under some systems, like OS/2, there may be different flavors
6949 of Perl executables, some of which may support fork, some not. Try
6950 changing the name you call Perl by to C<perl_>, C<perl__>, and so on.
6952 =item Unsupported script encoding %s
6954 (F) Your program file begins with a Unicode Byte Order Mark (BOM) which
6955 declares it to be in a Unicode encoding that Perl cannot read.
6957 =item Unsupported socket function "%s" called
6959 (F) Your machine doesn't support the Berkeley socket mechanism, or at
6960 least that's what Configure thought.
6962 =item Unterminated '(*...' argument in regex; marked by <-- HERE in m/%s/
6964 (F) You used a pattern of the form C<(*...:...)> but did not terminate
6965 the pattern with a C<)>. Fix the pattern and retry.
6967 =item Unterminated attribute list
6969 (F) The lexer found something other than a simple identifier at the
6970 start of an attribute, and it wasn't a semicolon or the start of a
6971 block. Perhaps you terminated the parameter list of the previous
6972 attribute too soon. See L<attributes>.
6974 =item Unterminated attribute parameter in attribute list
6976 (F) The lexer saw an opening (left) parenthesis character while parsing
6977 an attribute list, but the matching closing (right) parenthesis
6978 character was not found. You may need to add (or remove) a backslash
6979 character to get your parentheses to balance. See L<attributes>.
6981 =item Unterminated compressed integer
6983 (F) An argument to unpack("w",...) was incompatible with the BER
6984 compressed integer format and could not be converted to an integer.
6985 See L<perlfunc/pack>.
6987 =item Unterminated '(*...' construct in regex; marked by <-- HERE in m/%s/
6989 (F) You used a pattern of the form C<(*...)> but did not terminate
6990 the pattern with a C<)>. Fix the pattern and retry.
6992 =item Unterminated delimiter for here document
6994 (F) This message occurs when a here document label has an initial
6995 quotation mark but the final quotation mark is missing. Perhaps
7004 =item Unterminated \g... pattern in regex; marked by S<<-- HERE> in m/%s/
7006 =item Unterminated \g{...} pattern in regex; marked by S<<-- HERE> in m/%s/
7008 (F) In a regular expression, you had a C<\g> that wasn't followed by a
7009 proper group reference. In the case of C<\g{>, the closing brace is
7010 missing; otherwise the C<\g> must be followed by an integer. Fix the
7013 =item Unterminated <> operator
7015 (F) The lexer saw a left angle bracket in a place where it was expecting
7016 a term, so it's looking for the corresponding right angle bracket, and
7017 not finding it. Chances are you left some needed parentheses out
7018 earlier in the line, and you really meant a "less than".
7020 =item Unterminated verb pattern argument in regex; marked by S<<-- HERE> in
7023 (F) You used a pattern of the form C<(*VERB:ARG)> but did not terminate
7024 the pattern with a C<)>. Fix the pattern and retry.
7026 =item Unterminated verb pattern in regex; marked by S<<-- HERE> in m/%s/
7028 (F) You used a pattern of the form C<(*VERB)> but did not terminate
7029 the pattern with a C<)>. Fix the pattern and retry.
7031 =item untie attempted while %d inner references still exist
7033 (W untie) A copy of the object returned from C<tie> (or C<tied>) was
7034 still valid when C<untie> was called.
7036 =item Usage: POSIX::%s(%s)
7038 (F) You called a POSIX function with incorrect arguments.
7039 See L<POSIX/FUNCTIONS> for more information.
7041 =item Usage: Win32::%s(%s)
7043 (F) You called a Win32 function with incorrect arguments.
7044 See L<Win32> for more information.
7046 =item $[ used in %s (did you mean $] ?)
7048 (W syntax) You used C<$[> in a comparison, such as:
7054 You probably meant to use C<$]> instead. C<$[> is the base for indexing
7055 arrays. C<$]> is the Perl version number in decimal.
7057 =item Use "%s" instead of "%s"
7059 (F) The second listed construct is no longer legal. Use the first one
7062 =item Useless assignment to a temporary
7064 (W misc) You assigned to an lvalue subroutine, but what
7065 the subroutine returned was a temporary scalar about to
7066 be discarded, so the assignment had no effect.
7068 =item Useless (?-%s) - don't use /%s modifier in regex; marked by
7069 S<<-- HERE> in m/%s/
7071 (W regexp) You have used an internal modifier such as (?-o) that has no
7072 meaning unless removed from the entire regexp:
7074 if ($string =~ /(?-o)$pattern/o) { ... }
7078 if ($string =~ /$pattern/) { ... }
7080 The S<<-- HERE> shows whereabouts in the regular expression the problem was
7081 discovered. See L<perlre>.
7083 =item Useless localization of %s
7085 (W syntax) The localization of lvalues such as C<local($x=10)> is legal,
7086 but in fact the local() currently has no effect. This may change at
7087 some point in the future, but in the meantime such code is discouraged.
7089 =item Useless (?%s) - use /%s modifier in regex; marked by S<<-- HERE> in
7092 (W regexp) You have used an internal modifier such as (?o) that has no
7093 meaning unless applied to the entire regexp:
7095 if ($string =~ /(?o)$pattern/) { ... }
7099 if ($string =~ /$pattern/o) { ... }
7101 The S<<-- HERE> shows whereabouts in the regular expression the problem was
7102 discovered. See L<perlre>.
7104 =item Useless use of attribute "const"
7106 (W misc) The C<const> attribute has no effect except
7107 on anonymous closure prototypes. You applied it to
7108 a subroutine via L<attributes.pm|attributes>. This is only useful
7109 inside an attribute handler for an anonymous subroutine.
7111 =item Useless use of /d modifier in transliteration operator
7113 (W misc) You have used the /d modifier where the searchlist has the
7114 same length as the replacelist. See L<perlop> for more information
7115 about the /d modifier.
7117 =item Useless use of \E
7119 (W misc) You have a \E in a double-quotish string without a C<\U>,
7120 C<\L> or C<\Q> preceding it.
7122 =item Useless use of greediness modifier '%c' in regex; marked by S<<-- HERE> in m/%s/
7124 (W regexp) You specified something like these:
7129 The C<"?"> and C<"+"> don't have any effect, as they modify whether to
7130 match more or fewer when there is a choice, and by specifying to match
7131 exactly a given numer, there is no room left for a choice.
7133 =item Useless use of %s in void context
7135 (W void) You did something without a side effect in a context that does
7136 nothing with the return value, such as a statement that doesn't return a
7137 value from a block, or the left side of a scalar comma operator. Very
7138 often this points not to stupidity on your part, but a failure of Perl
7139 to parse your program the way you thought it would. For example, you'd
7140 get this if you mixed up your C precedence with Python precedence and
7145 when you meant to say
7147 ($one, $two) = (1, 2);
7149 Another common error is to use ordinary parentheses to construct a list
7150 reference when you should be using square or curly brackets, for
7155 when you should have said
7159 The square brackets explicitly turn a list value into a scalar value,
7160 while parentheses do not. So when a parenthesized list is evaluated in
7161 a scalar context, the comma is treated like C's comma operator, which
7162 throws away the left argument, which is not what you want. See
7163 L<perlref> for more on this.
7165 This warning will not be issued for numerical constants equal to 0 or 1
7166 since they are often used in statements like
7168 1 while sub_with_side_effects();
7170 String constants that would normally evaluate to 0 or 1 are warned
7173 =item Useless use of (?-p) in regex; marked by S<<-- HERE> in m/%s/
7175 (W regexp) The C<p> modifier cannot be turned off once set. Trying to do
7178 =item Useless use of "re" pragma
7180 (W) You did C<use re;> without any arguments. That isn't very useful.
7182 =item Useless use of sort in scalar context
7184 (W void) You used sort in scalar context, as in :
7188 This is not very useful, and perl currently optimizes this away.
7190 =item Useless use of %s with no values
7192 (W syntax) You used the push() or unshift() function with no arguments
7193 apart from the array, like C<push(@x)> or C<unshift(@foo)>. That won't
7194 usually have any effect on the array, so is completely useless. It's
7195 possible in principle that push(@tied_array) could have some effect
7196 if the array is tied to a class which implements a PUSH method. If so,
7197 you can write it as C<push(@tied_array,())> to avoid this warning.
7199 =item "use" not allowed in expression
7201 (F) The "use" keyword is recognized and executed at compile time, and
7202 returns no useful value. See L<perlmod>.
7204 =item Use of bare << to mean <<"" is forbidden
7206 (F) You are now required to use the explicitly quoted form if you wish
7207 to use an empty line as the terminator of the here-document.
7209 Use of a bare terminator was deprecated in Perl 5.000, and is a fatal
7210 error as of Perl 5.28.
7212 =item Use of /c modifier is meaningless in s///
7214 (W regexp) You used the /c modifier in a substitution. The /c
7215 modifier is not presently meaningful in substitutions.
7217 =item Use of /c modifier is meaningless without /g
7219 (W regexp) You used the /c modifier with a regex operand, but didn't
7220 use the /g modifier. Currently, /c is meaningful only when /g is
7221 used. (This may change in the future.)
7223 =item Use of code point 0x%s is not allowed; the permissible max is 0x%X
7225 =item Use of code point 0x%s is not allowed; the permissible max is 0x%X
7226 in regex; marked by <-- HERE in m/%s/
7228 (F) You used a code point that is not allowed, because it is too large.
7229 Unicode only allows code points up to 0x10FFFF, but Perl allows much
7230 larger ones. Earlier versions of Perl allowed code points above IV_MAX
7231 (0x7FFFFFF on 32-bit platforms, 0x7FFFFFFFFFFFFFFF on 64-bit platforms),
7232 however, this could possibly break the perl interpreter in some constructs,
7233 including causing it to hang in a few cases.
7235 If your code is to run on various platforms, keep in mind that the upper
7236 limit depends on the platform. It is much larger on 64-bit word sizes
7239 The use of out of range code points was deprecated in Perl 5.24, and
7240 became a fatal error in Perl 5.28.
7242 =item Use of each() on hash after insertion without resetting hash iterator results in undefined behavior
7244 (S internal) The behavior of C<each()> after insertion is undefined;
7245 it may skip items, or visit items more than once. Consider using
7246 C<keys()> instead of C<each()>.
7248 =item Use of := for an empty attribute list is not allowed
7250 (F) The construction C<my $x := 42> used to parse as equivalent to
7251 C<my $x : = 42> (applying an empty attribute list to C<$x>).
7252 This construct was deprecated in 5.12.0, and has now been made a syntax
7253 error, so C<:=> can be reclaimed as a new operator in the future.
7255 If you need an empty attribute list, for example in a code generator, add
7256 a space before the C<=>.
7258 =item Use of %s for non-UTF-8 locale is wrong. Assuming a UTF-8 locale
7260 (W locale) You are matching a regular expression using locale rules,
7261 and the specified construct was encountered. This construct is only
7262 valid for UTF-8 locales, which the current locale isn't. This doesn't
7263 make sense. Perl will continue, assuming a Unicode (UTF-8) locale, but
7264 the results are likely to be wrong.
7266 =item Use of freed value in iteration
7268 (F) Perhaps you modified the iterated array within the loop?
7269 This error is typically caused by code like the following:
7272 @a = () for (1,2,@a);
7274 You are not supposed to modify arrays while they are being iterated over.
7275 For speed and efficiency reasons, Perl internally does not do full
7276 reference-counting of iterated items, hence deleting such an item in the
7277 middle of an iteration causes Perl to see a freed value.
7279 =item Use of /g modifier is meaningless in split
7281 (W regexp) You used the /g modifier on the pattern for a C<split>
7282 operator. Since C<split> always tries to match the pattern
7283 repeatedly, the C</g> has no effect.
7285 =item Use of "goto" to jump into a construct is deprecated
7287 (D deprecated) Using C<goto> to jump from an outer scope into an inner
7288 scope is deprecated and should be avoided.
7290 This was deprecated in Perl 5.12.
7292 =item Use of '%s' in \p{} or \P{} is deprecated because: %s
7294 (D deprecated) Certain properties are deprecated by Unicode, and may
7295 eventually be removed from the Standard, at which time Perl will follow
7296 along. In the meantime, this message is raised to notify you.
7298 =item Use of inherited AUTOLOAD for non-method %s::%s() is no longer allowed
7300 (F) As an accidental feature, C<AUTOLOAD> subroutines were looked up as
7301 methods (using the C<@ISA> hierarchy), even when the subroutines to be
7302 autoloaded were called as plain functions (e.g. C<Foo::bar()>), not as
7303 methods (e.g. C<< Foo->bar() >> or C<< $obj->bar() >>).
7305 This was deprecated in Perl 5.004, and was made fatal in Perl 5.28.
7307 =item Use of %s in printf format not supported
7309 (F) You attempted to use a feature of printf that is accessible from
7310 only C. This usually means there's a better way to do it in Perl.
7312 =item Use of %s is not allowed in Unicode property wildcard
7313 subpatterns in regex; marked by S<<-- HERE> in m/%s/
7315 (F) You were using a wildcard subpattern a Unicode property value, and
7316 the subpattern contained something that is illegal. Not all regular
7317 expression capabilities are legal in such subpatterns, and this is one.
7318 Rewrite your subppattern to not use the offending construct.
7319 See L<perlunicode/Wildcards in Property Values>.
7321 =item Use of -l on filehandle%s
7323 (W io) A filehandle represents an opened file, and when you opened the file
7324 it already went past any symlink you are presumably trying to look for.
7325 The operation returned C<undef>. Use a filename instead.
7327 =item Use of reference "%s" as array index
7329 (W misc) You tried to use a reference as an array index; this probably
7330 isn't what you mean, because references in numerical context tend
7331 to be huge numbers, and so usually indicates programmer error.
7333 If you really do mean it, explicitly numify your reference, like so:
7334 C<$array[0+$ref]>. This warning is not given for overloaded objects,
7335 however, because you can overload the numification and stringification
7336 operators and then you presumably know what you are doing.
7338 =item Use of strings with code points over 0xFF as arguments to %s
7339 operator is not allowed
7341 (F) You tried to use one of the string bitwise operators (C<&> or C<|> or C<^> or
7342 C<~>) on a string containing a code point over 0xFF. The string bitwise
7343 operators treat their operands as strings of bytes, and values beyond
7344 0xFF are nonsensical in this context.
7346 Certain instances became fatal in Perl 5.28; others in perl 5.32.
7348 =item Use of strings with code points over 0xFF as arguments to vec is forbidden
7350 (F) You tried to use L<C<vec>|perlfunc/vec EXPR,OFFSET,BITS>
7351 on a string containing a code point over 0xFF, which is nonsensical here.
7353 This became fatal in Perl 5.32.
7355 =item Use of tainted arguments in %s is deprecated
7357 (W taint, deprecated) You have supplied C<system()> or C<exec()> with multiple
7358 arguments and at least one of them is tainted. This used to be allowed
7359 but will become a fatal error in a future version of perl. Untaint your
7360 arguments. See L<perlsec>.
7362 =item Use of unassigned code point or non-standalone grapheme for a
7363 delimiter is not allowed
7366 A grapheme is what appears to a native-speaker of a language to be a
7367 character. In Unicode (and hence Perl) a grapheme may actually be
7368 several adjacent characters that together form a complete grapheme. For
7369 example, there can be a base character, like "R" and an accent, like a
7370 circumflex "^", that appear when displayed to be a single character with
7371 the circumflex hovering over the "R". Perl currently allows things like
7372 that circumflex to be delimiters of strings, patterns, I<etc>. When
7373 displayed, the circumflex would look like it belongs to the character
7374 just to the left of it. In order to move the language to be able to
7375 accept graphemes as delimiters, we cannot allow the use of
7376 delimiters which aren't graphemes by themselves. Also, a delimiter must
7377 already be assigned (or known to be never going to be assigned) to try
7378 to future-proof code, for otherwise code that works today would fail to
7379 compile if the currently unassigned delimiter ends up being something
7380 that isn't a stand-alone grapheme. Because Unicode is never going to
7382 L<non-character code points|perlunicode/Noncharacter code points>, nor
7383 L<code points that are above the legal Unicode maximum|
7384 perlunicode/Beyond Unicode code points>, those can be delimiters, and
7387 =item Use of uninitialized value%s
7389 (W uninitialized) An undefined value was used as if it were already
7390 defined. It was interpreted as a "" or a 0, but maybe it was a mistake.
7391 To suppress this warning assign a defined value to your variables.
7393 To help you figure out what was undefined, perl will try to tell you
7394 the name of the variable (if any) that was undefined. In some cases
7395 it cannot do this, so it also tells you what operation you used the
7396 undefined value in. Note, however, that perl optimizes your program
7397 and the operation displayed in the warning may not necessarily appear
7398 literally in your program. For example, C<"that $foo"> is usually
7399 optimized into C<"that " . $foo>, and the warning will refer to the
7400 C<concatenation (.)> operator, even though there is no C<.> in
7403 =item "use re 'strict'" is experimental
7405 (S experimental::re_strict) The things that are different when a regular
7406 expression pattern is compiled under C<'strict'> are subject to change
7407 in future Perl releases in incompatible ways. This means that a pattern
7408 that compiles today may not in a future Perl release. This warning is
7409 to alert you to that risk.
7411 =item Use \x{...} for more than two hex characters in regex; marked by
7412 S<<-- HERE> in m/%s/
7414 (F) In a regular expression, you said something like
7418 Perl isn't sure if you meant this
7422 or if you meant this
7424 (?[ [ \x{BE} E F ] ])
7426 You need to add either braces or blanks to disambiguate.
7428 =item Using just the first character returned by \N{} in character class in
7429 regex; marked by S<<-- HERE> in m/%s/
7431 (W regexp) Named Unicode character escapes C<(\N{...})> may return
7432 a multi-character sequence. Even though a character class is
7433 supposed to match just one character of input, perl will match
7434 the whole thing correctly, except when the class is inverted
7435 (C<[^...]>), or the escape is the beginning or final end point of
7436 a range. For these, what should happen isn't clear at all. In
7437 these circumstances, Perl discards all but the first character
7438 of the returned sequence, which is not likely what you want.
7440 =item Using just the single character results returned by \p{} in
7441 (?[...]) in regex; marked by S<<-- HERE> in m/%s/
7443 (W regexp) Extended character classes currently cannot handle operands
7444 that evaluate to more than one character. These are removed from the
7445 results of the expansion of the C<\p{}>.
7447 This situation can happen, for example, in
7449 (?[ \p{name=/KATAKANA/} ])
7451 "KATAKANA LETTER AINU P" is a legal Unicode name (technically a "named
7452 sequence"), but it is actually two characters. The above expression
7453 with match only the Unicode names containing KATAKANA that represent
7456 =item Using /u for '%s' instead of /%s in regex; marked by S<<-- HERE> in m/%s/
7458 (W regexp) You used a Unicode boundary (C<\b{...}> or C<\B{...}>) in a
7459 portion of a regular expression where the character set modifiers C</a>
7460 or C</aa> are in effect. These two modifiers indicate an ASCII
7461 interpretation, and this doesn't make sense for a Unicode definition.
7462 The generated regular expression will compile so that the boundary uses
7463 all of Unicode. No other portion of the regular expression is affected.
7465 =item Using !~ with %s doesn't make sense
7467 (F) Using the C<!~> operator with C<s///r>, C<tr///r> or C<y///r> is
7468 currently reserved for future use, as the exact behavior has not
7469 been decided. (Simply returning the boolean opposite of the
7470 modified string is usually not particularly useful.)
7472 =item UTF-16 surrogate U+%X
7474 (S surrogate) You had a UTF-16 surrogate in a context where they are
7475 not considered acceptable. These code points, between U+D800 and
7476 U+DFFF (inclusive), are used by Unicode only for UTF-16. However, Perl
7477 internally allows all unsigned integer code points (up to the size limit
7478 available on your platform), including surrogates. But these can cause
7479 problems when being input or output, which is likely where this message
7480 came from. If you really really know what you are doing you can turn
7481 off this warning by C<no warnings 'surrogate';>.
7483 =item Value of %s can be "0"; test with defined()
7485 (W misc) In a conditional expression, you used <HANDLE>, <*> (glob),
7486 C<each()>, or C<readdir()> as a boolean value. Each of these constructs
7487 can return a value of "0"; that would make the conditional expression
7488 false, which is probably not what you intended. When using these
7489 constructs in conditional expressions, test their values with the
7490 C<defined> operator.
7492 =item Value of CLI symbol "%s" too long
7494 (W misc) A warning peculiar to VMS. Perl tried to read the value of an
7495 %ENV element from a CLI symbol table, and found a resultant string
7496 longer than 1024 characters. The return value has been truncated to
7499 =item Variable "%s" is not available
7501 (W closure) During compilation, an inner named subroutine or eval is
7502 attempting to capture an outer lexical that is not currently available.
7503 This can happen for one of two reasons. First, the outer lexical may be
7504 declared in an outer anonymous subroutine that has not yet been created.
7505 (Remember that named subs are created at compile time, while anonymous
7506 subs are created at run-time.) For example,
7508 sub { my $a; sub f { $a } }
7510 At the time that f is created, it can't capture the current value of $a,
7511 since the anonymous subroutine hasn't been created yet. Conversely,
7512 the following won't give a warning since the anonymous subroutine has by
7513 now been created and is live:
7515 sub { my $a; eval 'sub f { $a }' }->();
7517 The second situation is caused by an eval accessing a variable that has
7518 gone out of scope, for example,
7526 Here, when the '$a' in the eval is being compiled, f() is not currently
7527 being executed, so its $a is not available for capture.
7529 =item Variable "%s" is not imported%s
7531 (S misc) With "use strict" in effect, you referred to a global variable
7532 that you apparently thought was imported from another module, because
7533 something else of the same name (usually a subroutine) is exported by
7534 that module. It usually means you put the wrong funny character on the
7535 front of your variable.
7537 =item Variable length lookbehind not implemented in regex m/%s/
7539 (F) B<This message no longer should be raised as of Perl 5.30.> It is
7540 retained in this document as a convenience for people using an earlier
7543 In Perl 5.30 and earlier, lookbehind is allowed
7544 only for subexpressions whose length is fixed and
7545 known at compile time. For positive lookbehind, you can use the C<\K>
7546 regex construct as a way to get the equivalent functionality. See
7547 L<(?<=pattern) and \K in perlre|perlre/\K>.
7549 Starting in Perl 5.18, there are non-obvious Unicode rules under C</i>
7550 that can match variably, but which you might not think could. For
7551 example, the substring C<"ss"> can match the single character LATIN
7552 SMALL LETTER SHARP S. Here's a complete list of the current ones
7553 affecting ASCII characters:
7556 sequence Matches single letter under /i
7557 FF U+FB00 LATIN SMALL LIGATURE FF
7558 FFI U+FB03 LATIN SMALL LIGATURE FFI
7559 FFL U+FB04 LATIN SMALL LIGATURE FFL
7560 FI U+FB01 LATIN SMALL LIGATURE FI
7561 FL U+FB02 LATIN SMALL LIGATURE FL
7562 SS U+00DF LATIN SMALL LETTER SHARP S
7563 U+1E9E LATIN CAPITAL LETTER SHARP S
7564 ST U+FB06 LATIN SMALL LIGATURE ST
7565 U+FB05 LATIN SMALL LIGATURE LONG S T
7567 This list is subject to change, but is quite unlikely to.
7568 Each ASCII sequence can be any combination of upper- and lowercase.
7570 You can avoid this by using a bracketed character class in the
7571 lookbehind assertion, like
7576 This fools Perl into not matching the ligatures.
7578 Another option for Perls starting with 5.16, if you only care about
7579 ASCII matches, is to add the C</aa> modifier to the regex. This will
7580 exclude all these non-obvious matches, thus getting rid of this message.
7583 use if $] ge 5.016, re => '/aa';
7585 to apply C</aa> to all regular expressions compiled within its scope.
7588 =item "%s" variable %s masks earlier declaration in same %s
7590 (W shadow) A "my", "our" or "state" variable has been redeclared in the
7591 current scope or statement, effectively eliminating all access to the
7592 previous instance. This is almost always a typographical error. Note
7593 that the earlier variable will still exist until the end of the scope
7594 or until all closure references to it are destroyed.
7596 =item Variable syntax
7598 (A) You've accidentally run your script through B<csh> instead
7599 of Perl. Check the #! line, or manually feed your script into
7602 =item Variable "%s" will not stay shared
7604 (W closure) An inner (nested) I<named> subroutine is referencing a
7605 lexical variable defined in an outer named subroutine.
7607 When the inner subroutine is called, it will see the value of
7608 the outer subroutine's variable as it was before and during the *first*
7609 call to the outer subroutine; in this case, after the first call to the
7610 outer subroutine is complete, the inner and outer subroutines will no
7611 longer share a common value for the variable. In other words, the
7612 variable will no longer be shared.
7614 This problem can usually be solved by making the inner subroutine
7615 anonymous, using the C<sub {}> syntax. When inner anonymous subs that
7616 reference variables in outer subroutines are created, they
7617 are automatically rebound to the current values of such variables.
7619 =item vector argument not supported with alpha versions
7621 (S printf) The %vd (s)printf format does not support version objects
7624 =item Verb pattern '%s' has a mandatory argument in regex; marked by
7625 S<<-- HERE> in m/%s/
7627 (F) You used a verb pattern that requires an argument. Supply an
7628 argument or check that you are using the right verb.
7630 =item Verb pattern '%s' may not have an argument in regex; marked by
7631 S<<-- HERE> in m/%s/
7633 (F) You used a verb pattern that is not allowed an argument. Remove the
7634 argument or check that you are using the right verb.
7636 =item Version control conflict marker
7638 (F) The parser found a line starting with C<E<lt><<<<<<>,
7639 C<E<gt>E<gt>E<gt>E<gt>E<gt>E<gt>E<gt>>, or C<=======>. These may be left by a
7640 version control system to mark conflicts after a failed merge operation.
7642 =item Version number must be a constant number
7644 (P) The attempt to translate a C<use Module n.n LIST> statement into
7645 its equivalent C<BEGIN> block found an internal inconsistency with
7648 =item Version string '%s' contains invalid data; ignoring: '%s'
7650 (W misc) The version string contains invalid characters at the end, which
7653 =item Warning: something's wrong
7655 (W) You passed warn() an empty string (the equivalent of C<warn "">) or
7656 you called it with no args and C<$@> was empty.
7658 =item Warning: unable to close filehandle %s properly
7660 (S) The implicit close() done by an open() got an error indication on
7661 the close(). This usually indicates your file system ran out of disk
7664 =item Warning: unable to close filehandle properly: %s
7666 =item Warning: unable to close filehandle %s properly: %s
7668 (S io) There were errors during the implicit close() done on a filehandle
7669 when its reference count reached zero while it was still open, e.g.:
7672 open my $fh, '>', $file or die "open: '$file': $!\n";
7673 print $fh $data or die "print: $!";
7674 } # implicit close here
7676 Because various errors may only be detected by close() (e.g. buffering could
7677 allow the C<print> in this example to return true even when the disk is full),
7678 it is dangerous to ignore its result. So when it happens implicitly, perl
7679 will signal errors by warning.
7681 B<Prior to version 5.22.0, perl ignored such errors>, so the common idiom shown
7682 above was liable to cause B<silent data loss>.
7684 =item Warning: Use of "%s" without parentheses is ambiguous
7686 (S ambiguous) You wrote a unary operator followed by something that
7687 looks like a binary operator that could also have been interpreted as a
7688 term or unary operator. For instance, if you know that the rand
7689 function has a default argument of 1.0, and you write
7693 you may THINK you wrote the same thing as
7697 but in actual fact, you got
7701 So put in parentheses to say what you really mean.
7703 =item when is experimental
7705 (S experimental::smartmatch) C<when> depends on smartmatch, which is
7706 experimental. Additionally, it has several special cases that may
7707 not be immediately obvious, and their behavior may change or
7708 even be removed in any future release of perl. See the explanation
7709 under L<perlsyn/Experimental Details on given and when>.
7711 =item Wide character in %s
7713 (S utf8) Perl met a wide character (ordinal >255) when it wasn't
7714 expecting one. This warning is by default on for I/O (like print).
7716 If this warning does come from I/O, the easiest
7717 way to quiet it is simply to add the C<:utf8> layer, I<e.g.>,
7718 S<C<binmode STDOUT, ':utf8'>>. Another way to turn off the warning is
7719 to add S<C<no warnings 'utf8';>> but that is often closer to
7720 cheating. In general, you are supposed to explicitly mark the
7721 filehandle with an encoding, see L<open> and L<perlfunc/binmode>.
7723 If the warning comes from other than I/O, this diagnostic probably
7724 indicates that incorrect results are being obtained. You should examine
7725 your code to determine how a wide character is getting to an operation
7726 that doesn't handle them.
7728 =item Wide character (U+%X) in %s
7730 (W locale) While in a single-byte locale (I<i.e.>, a non-UTF-8
7731 one), a multi-byte character was encountered. Perl considers this
7732 character to be the specified Unicode code point. Combining non-UTF-8
7733 locales and Unicode is dangerous. Almost certainly some characters
7734 will have two different representations. For example, in the ISO 8859-7
7735 (Greek) locale, the code point 0xC3 represents a Capital Gamma. But so
7736 also does 0x393. This will make string comparisons unreliable.
7738 You likely need to figure out how this multi-byte character got mixed up
7739 with your single-byte locale (or perhaps you thought you had a UTF-8
7740 locale, but Perl disagrees).
7742 =item Within []-length '%c' not allowed
7744 (F) The count in the (un)pack template may be replaced by C<[TEMPLATE]>
7745 only if C<TEMPLATE> always matches the same amount of packed bytes that
7746 can be determined from the template alone. This is not possible if
7747 it contains any of the codes @, /, U, u, w or a *-length. Redesign
7750 =item While trying to resolve method call %s->%s() can not locate package "%s" yet it is mentioned in @%s::ISA (perhaps you forgot to load "%s"?)
7752 (W syntax) It is possible that the C<@ISA> contains a misspelled or never loaded
7753 package name, which can result in perl choosing an unexpected parent
7754 class's method to resolve the method call. If this is deliberate you
7755 can do something like
7757 @Missing::Package::ISA = ();
7759 to silence the warnings, otherwise you should correct the package name, or
7760 ensure that the package is loaded prior to the method call.
7762 =item %s() with negative argument
7764 (S misc) Certain operations make no sense with negative arguments.
7765 Warning is given and the operation is not done.
7767 =item write() on closed filehandle %s
7769 (W closed) The filehandle you're writing to got itself closed sometime
7770 before now. Check your control flow.
7772 =item %s "\x%X" does not map to Unicode
7774 (S utf8) When reading in different encodings, Perl tries to
7775 map everything into Unicode characters. The bytes you read
7776 in are not legal in this encoding. For example
7778 utf8 "\xE4" does not map to Unicode
7780 if you try to read in the a-diaereses Latin-1 as UTF-8.
7782 =item 'X' outside of string
7784 (F) You had a (un)pack template that specified a relative position before
7785 the beginning of the string being (un)packed. See L<perlfunc/pack>.
7787 =item 'x' outside of string in unpack
7789 (F) You had a pack template that specified a relative position after
7790 the end of the string being unpacked. See L<perlfunc/pack>.
7792 =item YOU HAVEN'T DISABLED SET-ID SCRIPTS IN THE KERNEL YET!
7794 (F) And you probably never will, because you probably don't have the
7795 sources to your kernel, and your vendor probably doesn't give a rip
7796 about what you want. There is a vulnerability anywhere that you have a
7797 set-id script, and to close it you need to remove the set-id bit from
7798 the script that you're attempting to run. To actually run the script
7799 set-id, your best bet is to put a set-id C wrapper around your script.
7801 =item You need to quote "%s"
7803 (W syntax) You assigned a bareword as a signal handler name.
7804 Unfortunately, you already have a subroutine of that name declared,
7805 which means that Perl 5 will try to call the subroutine when the
7806 assignment is executed, which is probably not what you want. (If it IS
7807 what you want, put an & in front.)
7809 =item Your random numbers are not that random
7811 (F) When trying to initialize the random seed for hashes, Perl could
7812 not get any randomness out of your system. This usually indicates
7813 Something Very Wrong.
7815 =item Zero length \N{} in regex; marked by S<<-- HERE> in m/%s/
7817 (F) Named Unicode character escapes (C<\N{...}>) may return a zero-length
7818 sequence. Such an escape was used in an extended character class, i.e.
7819 C<(?[...])>, or under C<use re 'strict'>, which is not permitted. Check
7820 that the correct escape has been used, and the correct charnames handler
7821 is in scope. The S<<-- HERE> shows whereabouts in the regular
7822 expression the problem was discovered.
7828 L<warnings>, L<diagnostics>.