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1=head1 NAME
2
3perldiag - various Perl diagnostics
4
5=head1 DESCRIPTION
6
7These messages are classified as follows (listed in increasing order of
8desperation):
9
10 (W) A warning (optional).
d1d15184 11 (D) A deprecation (enabled by default).
00eb3f2b 12 (S) A severe warning (enabled by default).
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13 (F) A fatal error (trappable).
14 (P) An internal error you should never see (trappable).
54310121 15 (X) A very fatal error (nontrappable).
cb1a09d0 16 (A) An alien error message (not generated by Perl).
a0d0e21e 17
75b44862 18The majority of messages from the first three classifications above
64977eb6 19(W, D & S) can be controlled using the C<warnings> pragma.
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20
21If a message can be controlled by the C<warnings> pragma, its warning
22category is included with the classification letter in the description
466416ed 23below. E.g. C<(W closed)> means a warning in the C<closed> category.
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24
25Optional warnings are enabled by using the C<warnings> pragma or the B<-w>
fa816bf3 26and B<-W> switches. Warnings may be captured by setting C<$SIG{__WARN__}>
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27to a reference to a routine that will be called on each warning instead
28of printing it. See L<perlvar>.
29
b7eceb5b 30Severe warnings are always enabled, unless they are explicitly disabled
e476b1b5 31with the C<warnings> pragma or the B<-X> switch.
4438c4b7 32
748a9306 33Trappable errors may be trapped using the eval operator. See
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34L<perlfunc/eval>. In almost all cases, warnings may be selectively
35disabled or promoted to fatal errors using the C<warnings> pragma.
36See L<warnings>.
a0d0e21e 37
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38The messages are in alphabetical order, without regard to upper or
39lower-case. Some of these messages are generic. Spots that vary are
40denoted with a %s or other printf-style escape. These escapes are
41ignored by the alphabetical order, as are all characters other than
42letters. To look up your message, just ignore anything that is not a
43letter.
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44
45=over 4
46
6df41af2 47=item accept() on closed socket %s
33633739 48
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49(W closed) You tried to do an accept on a closed socket. Did you forget
50to check the return value of your socket() call? See
51L<perlfunc/accept>.
33633739 52
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53=item Aliasing via reference is experimental
54
55(S experimental::refaliasing) This warning is emitted if you use
56a reference constructor on the left-hand side of an assignment to
57alias one variable to another. Simply suppress the warning if you
58want to use the feature, but know that in doing so you are taking
59the risk of using an experimental feature which may change or be
60removed in a future Perl version:
61
62 no warnings "experimental::refaliasing";
63 use feature "refaliasing";
64 \$x = \$y;
65
de42a5a9 66=item Allocation too large: %x
a0d0e21e 67
6df41af2 68(X) You can't allocate more than 64K on an MS-DOS machine.
a0d0e21e 69
04f74579 70=item '%c' allowed only after types %s in %s
ef54e1a4 71
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72(F) The modifiers '!', '<' and '>' are allowed in pack() or unpack() only
73after certain types. See L<perlfunc/pack>.
ef54e1a4 74
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75=item alpha->numify() is lossy
76
77(W numeric) An alpha version can not be numified without losing
78information.
79
6df41af2 80=item Ambiguous call resolved as CORE::%s(), qualify as such or use &
43192e07 81
75b44862 82(W ambiguous) A subroutine you have declared has the same name as a Perl
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83keyword, and you have used the name without qualification for calling
84one or the other. Perl decided to call the builtin because the
85subroutine is not imported.
43192e07 86
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87To force interpretation as a subroutine call, either put an ampersand
88before the subroutine name, or qualify the name with its package.
89Alternatively, you can import the subroutine (or pretend that it's
90imported with the C<use subs> pragma).
43192e07 91
6df41af2 92To silently interpret it as the Perl operator, use the C<CORE::> prefix
496a33f5 93on the operator (e.g. C<CORE::log($x)>) or declare the subroutine
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94to be an object method (see L<perlsub/"Subroutine Attributes"> or
95L<attributes>).
43192e07 96
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97=item Ambiguous range in transliteration operator
98
99(F) You wrote something like C<tr/a-z-0//> which doesn't mean anything at
100all. To include a C<-> character in a transliteration, put it either
101first or last. (In the past, C<tr/a-z-0//> was synonymous with
102C<tr/a-y//>, which was probably not what you would have expected.)
103
6df41af2 104=item Ambiguous use of %s resolved as %s
43192e07 105
7c7af292 106(S ambiguous) You said something that may not be interpreted the way
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107you thought. Normally it's pretty easy to disambiguate it by supplying
108a missing quote, operator, parenthesis pair or declaration.
a0d0e21e 109
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110=item Ambiguous use of -%s resolved as -&%s()
111
112(S ambiguous) You wrote something like C<-foo>, which might be the
113string C<"-foo">, or a call to the function C<foo>, negated. If you meant
114the string, just write C<"-foo">. If you meant the function call,
115write C<-foo()>.
116
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117=item Ambiguous use of %c resolved as operator %c
118
7c7af292 119(S ambiguous) C<%>, C<&>, and C<*> are both infix operators (modulus,
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120bitwise and, and multiplication) I<and> initial special characters
121(denoting hashes, subroutines and typeglobs), and you said something
122like C<*foo * foo> that might be interpreted as either of them. We
123assumed you meant the infix operator, but please try to make it more
124clear -- in the example given, you might write C<*foo * foo()> if you
125really meant to multiply a glob by the result of calling a function.
d8225693 126
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127=item Ambiguous use of %c{%s} resolved to %c%s
128
129(W ambiguous) You wrote something like C<@{foo}>, which might be
130asking for the variable C<@foo>, or it might be calling a function
131named foo, and dereferencing it as an array reference. If you wanted
1cecf2c0 132the variable, you can just write C<@foo>. If you wanted to call the
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133function, write C<@{foo()}> ... or you could just not have a variable
134and a function with the same name, and save yourself a lot of trouble.
135
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136=item Ambiguous use of %c{%s[...]} resolved to %c%s[...]
137
138=item Ambiguous use of %c{%s{...}} resolved to %c%s{...}
4da60377 139
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140(W ambiguous) You wrote something like C<${foo[2]}> (where foo represents
141the name of a Perl keyword), which might be looking for element number
1422 of the array named C<@foo>, in which case please write C<$foo[2]>, or you
143might have meant to pass an anonymous arrayref to the function named
144foo, and then do a scalar deref on the value it returns. If you meant
145that, write C<${foo([2])}>.
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146
147In regular expressions, the C<${foo[2]}> syntax is sometimes necessary
148to disambiguate between array subscripts and character classes.
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149C</$length[2345]/>, for instance, will be interpreted as C<$length> followed
150by the character class C<[2345]>. If an array subscript is what you
151want, you can avoid the warning by changing C</${length[2345]}/> to the
152unsightly C</${\$length[2345]}/>, by renaming your array to something
153that does not coincide with a built-in keyword, or by simply turning
154off warnings with C<no warnings 'ambiguous';>.
4da60377 155
6df41af2 156=item '|' and '<' may not both be specified on command line
a0d0e21e 157
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158(F) An error peculiar to VMS. Perl does its own command line
159redirection, and found that STDIN was a pipe, and that you also tried to
160redirect STDIN using '<'. Only one STDIN stream to a customer, please.
c9f97d15 161
6df41af2 162=item '|' and '>' may not both be specified on command line
1028017a 163
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164(F) An error peculiar to VMS. Perl does its own command line
165redirection, and thinks you tried to redirect stdout both to a file and
166into a pipe to another command. You need to choose one or the other,
167though nothing's stopping you from piping into a program or Perl script
168which 'splits' output into two streams, such as
1028017a 169
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170 open(OUT,">$ARGV[0]") or die "Can't write to $ARGV[0]: $!";
171 while (<STDIN>) {
172 print;
173 print OUT;
174 }
175 close OUT;
c9f97d15 176
6df41af2 177=item Applying %s to %s will act on scalar(%s)
eb6e2d6f 178
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179(W misc) The pattern match (C<//>), substitution (C<s///>), and
180transliteration (C<tr///>) operators work on scalar values. If you apply
be771a83 181one of them to an array or a hash, it will convert the array or hash to
ac036724 182a scalar value (the length of an array, or the population info of a
183hash) and then work on that scalar value. This is probably not what
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184you meant to do. See L<perlfunc/grep> and L<perlfunc/map> for
185alternatives.
eb6e2d6f 186
6df41af2 187=item Arg too short for msgsnd
76cd736e 188
6df41af2 189(F) msgsnd() requires a string at least as long as sizeof(long).
76cd736e 190
f86702cc 191=item Argument "%s" isn't numeric%s
a0d0e21e 192
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193(W numeric) The indicated string was fed as an argument to an operator
194that expected a numeric value instead. If you're fortunate the message
195will identify which operator was so unfortunate.
a0d0e21e 196
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197Note that for the C<Inf> and C<NaN> (infinity and not-a-number) the
198definition of "numeric" is somewhat unusual: the strings themselves
199(like "Inf") are considered numeric, and anything following them is
200considered non-numeric.
201
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202=item Argument list not closed for PerlIO layer "%s"
203
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204(W layer) When pushing a layer with arguments onto the Perl I/O
205system you forgot the ) that closes the argument list. (Layers
206take care of transforming data between external and internal
207representations.) Perl stopped parsing the layer list at this
208point and did not attempt to push this layer. If your program
209didn't explicitly request the failing operation, it may be the
210result of the value of the environment variable PERLIO.
b4581f09 211
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212=item Argument "%s" treated as 0 in increment (++)
213
214(W numeric) The indicated string was fed as an argument to the C<++>
215operator which expects either a number or a string matching
216C</^[a-zA-Z]*[0-9]*\z/>. See L<perlop/Auto-increment and
217Auto-decrement> for details.
218
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219=item assertion botched: %s
220
21b5e840 221(X) The malloc package that comes with Perl had an internal failure.
a0d0e21e 222
0eacef8e 223=item Assertion %s failed: file "%s", line %d
a0d0e21e 224
21b5e840 225(X) A general assertion failed. The file in question must be examined.
a0d0e21e 226
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227=item Assigned value is not a reference
228
229(F) You tried to assign something that was not a reference to an lvalue
230reference (e.g., C<\$x = $y>). If you meant to make $x an alias to $y, use
231C<\$x = \$y>.
232
233=item Assigned value is not %s reference
234
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235(F) You tried to assign a reference to a reference constructor, but the
236two references were not of the same type. You cannot alias a scalar to
237an array, or an array to a hash; the two types must match.
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238
239 \$x = \@y; # error
240 \@x = \%y; # error
241 $y = [];
242 \$x = $y; # error; did you mean \$y?
243
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244=item Assigning non-zero to $[ is no longer possible
245
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246(F) When the "array_base" feature is disabled (e.g., under C<use v5.16;>)
247the special variable C<$[>, which is deprecated, is now a fixed zero value.
82122228 248
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249=item Assignment to both a list and a scalar
250
251(F) If you assign to a conditional operator, the 2nd and 3rd arguments
252must either both be scalars or both be lists. Otherwise Perl won't
253know which context to supply to the right side.
254
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255=item Assuming NOT a POSIX class since %s in regex; marked by S<<-- HERE> in m/%s/
256
257(W regexp) You had something like these:
258
259 [[:alnum]]
260 [[:digit:xyz]
261
262They look like they might have been meant to be the POSIX classes
263C<[:alnum:]> or C<[:digit:]>. If so, they should be written:
264
265 [[:alnum:]]
266 [[:digit:]xyz]
267
268Since these aren't legal POSIX class specifications, but are legal
269bracketed character classes, Perl treats them as the latter. In the
270first example, it matches the characters C<":">, C<"[">, C<"a">, C<"l">,
271C<"m">, C<"n">, and C<"u">.
272
273If these weren't meant to be POSIX classes, this warning message is
274spurious, and can be suppressed by reordering things, such as
275
276 [[al:num]]
277
278or
279
280 [[:munla]]
281
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282=item <> at require-statement should be quotes
283
284(F) You wrote C<< require <file> >> when you should have written
285C<require 'file'>.
286
2393f1b9 287=item Attempt to access disallowed key '%s' in a restricted hash
1b1f1335 288
49293501 289(F) The failing code has attempted to get or set a key which is not in
2393f1b9 290the current set of allowed keys of a restricted hash.
49293501 291
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292=item Attempt to bless into a freed package
293
294(F) You wrote C<bless $foo> with one argument after somehow causing
295the current package to be freed. Perl cannot figure out what to
296do, so it throws up in hands in despair.
297
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298=item Attempt to bless into a reference
299
300(F) The CLASSNAME argument to the bless() operator is expected to be
57dedab9 301the name of the package to bless the resulting object into. You've
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302supplied instead a reference to something: perhaps you wrote
303
304 bless $self, $proto;
305
306when you intended
307
308 bless $self, ref($proto) || $proto;
309
310If you actually want to bless into the stringified version
311of the reference supplied, you need to stringify it yourself, for
312example by:
313
314 bless $self, "$proto";
315
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316=item Attempt to clear deleted array
317
318(S debugging) An array was assigned to when it was being freed.
319Freed values are not supposed to be visible to Perl code. This
320can also happen if XS code calls C<av_clear> from a custom magic
321callback on the array.
322
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323=item Attempt to delete disallowed key '%s' from a restricted hash
324
325(F) The failing code attempted to delete from a restricted hash a key
326which is not in its key set.
327
328=item Attempt to delete readonly key '%s' from a restricted hash
329
330(F) The failing code attempted to delete a key whose value has been
331declared readonly from a restricted hash.
332
de42a5a9 333=item Attempt to free non-arena SV: 0x%x
a0d0e21e 334
f84fe999 335(S internal) All SV objects are supposed to be allocated from arenas
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336that will be garbage collected on exit. An SV was discovered to be
337outside any of those arenas.
a0d0e21e 338
12578ffb 339=item Attempt to free nonexistent shared string '%s'%s
bbce6d69 340
f84fe999 341(S internal) Perl maintains a reference-counted internal table of
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342strings to optimize the storage and access of hash keys and other
343strings. This indicates someone tried to decrement the reference count
344of a string that can no longer be found in the table.
bbce6d69 345
7d5b40b4 346=item Attempt to free temp prematurely: SV 0x%x
a0d0e21e 347
f84fe999 348(S debugging) Mortalized values are supposed to be freed by the
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349free_tmps() routine. This indicates that something else is freeing the
350SV before the free_tmps() routine gets a chance, which means that the
351free_tmps() routine will be freeing an unreferenced scalar when it does
352try to free it.
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353
354=item Attempt to free unreferenced glob pointers
355
f84fe999 356(S internal) The reference counts got screwed up on symbol aliases.
a0d0e21e 357
7d5b40b4 358=item Attempt to free unreferenced scalar: SV 0x%x
a0d0e21e 359
8f7e4d2c 360(S internal) Perl went to decrement the reference count of a scalar to
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361see if it would go to 0, and discovered that it had already gone to 0
362earlier, and should have been freed, and in fact, probably was freed.
363This could indicate that SvREFCNT_dec() was called too many times, or
364that SvREFCNT_inc() was called too few times, or that the SV was
365mortalized when it shouldn't have been, or that memory has been
366corrupted.
a0d0e21e 367
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368=item Attempt to pack pointer to temporary value
369
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370(W pack) You tried to pass a temporary value (like the result of a
371function, or a computed expression) to the "p" pack() template. This
372means the result contains a pointer to a location that could become
373invalid anytime, even before the end of the current statement. Use
374literals or global values as arguments to the "p" pack() template to
375avoid this warning.
84902520 376
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377=item Attempt to reload %s aborted.
378
379(F) You tried to load a file with C<use> or C<require> that failed to
380compile once already. Perl will not try to compile this file again
381unless you delete its entry from %INC. See L<perlfunc/require> and
382L<perlvar/%INC>.
383
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384=item Attempt to set length of freed array
385
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386(W misc) You tried to set the length of an array which has
387been freed. You can do this by storing a reference to the
388scalar representing the last index of an array and later
389assigning through that reference. For example
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390
391 $r = do {my @a; \$#a};
392 $$r = 503
393
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394=item Attempt to use reference as lvalue in substr
395
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396(W substr) You supplied a reference as the first argument to substr()
397used as an lvalue, which is pretty strange. Perhaps you forgot to
398dereference it first. See L<perlfunc/substr>.
b7a902f4 399
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400=item Attribute "locked" is deprecated
401
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402(D deprecated) You have used the attributes pragma to modify the
403"locked" attribute on a code reference. The :locked attribute is
404obsolete, has had no effect since 5005 threads were removed, and
405will be removed in a future release of Perl 5.
c32124fe 406
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407=item Attribute prototype(%s) discards earlier prototype attribute in same sub
408
409(W misc) A sub was declared as sub foo : prototype(A) : prototype(B) {}, for
410example. Since each sub can only have one prototype, the earlier
411declaration(s) are discarded while the last one is applied.
412
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413=item Attribute "unique" is deprecated
414
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415(D deprecated) You have used the attributes pragma to modify
416the "unique" attribute on an array, hash or scalar reference.
417The :unique attribute has had no effect since Perl 5.8.8, and
418will be removed in a future release of Perl 5.
f1a3ce43 419
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420=item av_reify called on tied array
421
422(S debugging) This indicates that something went wrong and Perl got I<very>
423confused about C<@_> or C<@DB::args> being tied.
424
de42a5a9 425=item Bad arg length for %s, is %u, should be %d
a0d0e21e 426
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427(F) You passed a buffer of the wrong size to one of msgctl(), semctl()
428or shmctl(). In C parlance, the correct sizes are, respectively,
5f05dabc 429S<sizeof(struct msqid_ds *)>, S<sizeof(struct semid_ds *)>, and
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430S<sizeof(struct shmid_ds *)>.
431
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432=item Bad evalled substitution pattern
433
496a33f5 434(F) You've used the C</e> switch to evaluate the replacement for a
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435substitution, but perl found a syntax error in the code to evaluate,
436most likely an unexpected right brace '}'.
437
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438=item Bad filehandle: %s
439
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440(F) A symbol was passed to something wanting a filehandle, but the
441symbol has no filehandle associated with it. Perhaps you didn't do an
442open(), or did it in another package.
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443
444=item Bad free() ignored
445
be771a83 446(S malloc) An internal routine called free() on something that had never
fa816bf3 447been malloc()ed in the first place. Mandatory, but can be disabled by
9ea8bc6d 448setting environment variable C<PERL_BADFREE> to 0.
33c8a3fe 449
9ea8bc6d 450This message can be seen quite often with DB_File on systems with "hard"
6903afa2 451dynamic linking, like C<AIX> and C<OS/2>. It is a bug of C<Berkeley DB>
be771a83 452which is left unnoticed if C<DB> uses I<forgiving> system malloc().
a0d0e21e 453
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454=item Bad hash
455
456(P) One of the internal hash routines was passed a null HV pointer.
457
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458=item Badly placed ()'s
459
460(A) You've accidentally run your script through B<csh> instead
461of Perl. Check the #! line, or manually feed your script into
462Perl yourself.
463
a7cb8dae 464=item Bad name after %s
a0d0e21e 465
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466(F) You started to name a symbol by using a package prefix, and then
467didn't finish the symbol. In particular, you can't interpolate outside
468of quotes, so
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469
470 $var = 'myvar';
471 $sym = mypack::$var;
472
473is not the same as
474
475 $var = 'myvar';
476 $sym = "mypack::$var";
477
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478=item Bad plugin affecting keyword '%s'
479
480(F) An extension using the keyword plugin mechanism violated the
481plugin API.
482
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483=item Bad realloc() ignored
484
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485(S malloc) An internal routine called realloc() on something that
486had never been malloc()ed in the first place. Mandatory, but can
487be disabled by setting the environment variable C<PERL_BADFREE> to 1.
4ad56ec9 488
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489=item Bad symbol for array
490
491(P) An internal request asked to add an array entry to something that
492wasn't a symbol table entry.
493
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494=item Bad symbol for dirhandle
495
496(P) An internal request asked to add a dirhandle entry to something
497that wasn't a symbol table entry.
498
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499=item Bad symbol for filehandle
500
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501(P) An internal request asked to add a filehandle entry to something
502that wasn't a symbol table entry.
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503
504=item Bad symbol for hash
505
506(P) An internal request asked to add a hash entry to something that
507wasn't a symbol table entry.
508
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509=item Bad symbol for scalar
510
511(P) An internal request asked to add a scalar entry to something that
512wasn't a symbol table entry.
513
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514=item Bareword found in conditional
515
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516(W bareword) The compiler found a bareword where it expected a
517conditional, which often indicates that an || or && was parsed as part
518of the last argument of the previous construct, for example:
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519
520 open FOO || die;
521
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522It may also indicate a misspelled constant that has been interpreted as
523a bareword:
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524
525 use constant TYPO => 1;
526 if (TYOP) { print "foo" }
527
528The C<strict> pragma is useful in avoiding such errors.
529
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530=item Bareword "%s" not allowed while "strict subs" in use
531
532(F) With "strict subs" in use, a bareword is only allowed as a
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533subroutine identifier, in curly brackets or to the left of the "=>"
534symbol. Perhaps you need to predeclare a subroutine?
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535
536=item Bareword "%s" refers to nonexistent package
537
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GS
538(W bareword) You used a qualified bareword of the form C<Foo::>, but the
539compiler saw no other uses of that namespace before that point. Perhaps
540you need to predeclare a package?
6df41af2 541
a0d0e21e
LW
542=item BEGIN failed--compilation aborted
543
be771a83
GS
544(F) An untrapped exception was raised while executing a BEGIN
545subroutine. Compilation stops immediately and the interpreter is
546exited.
a0d0e21e 547
68dc0745
PP
548=item BEGIN not safe after errors--compilation aborted
549
550(F) Perl found a C<BEGIN {}> subroutine (or a C<use> directive, which
be771a83
GS
551implies a C<BEGIN {}>) after one or more compilation errors had already
552occurred. Since the intended environment for the C<BEGIN {}> could not
553be guaranteed (due to the errors), and since subsequent code likely
554depends on its correct operation, Perl just gave up.
68dc0745 555
c782d7ee 556=item \%d better written as $%d
6df41af2 557
be771a83
GS
558(W syntax) Outside of patterns, backreferences live on as variables.
559The use of backslashes is grandfathered on the right-hand side of a
560substitution, but stylistically it's better to use the variable form
561because other Perl programmers will expect it, and it works better if
562there are more than 9 backreferences.
6df41af2 563
252aa082
JH
564=item Binary number > 0b11111111111111111111111111111111 non-portable
565
e476b1b5 566(W portable) The binary number you specified is larger than 2**32-1
9e24b6e2
JH
567(4294967295) and therefore non-portable between systems. See
568L<perlport> for more on portability concerns.
252aa082 569
69282e91 570=item bind() on closed socket %s
a0d0e21e 571
be771a83
GS
572(W closed) You tried to do a bind on a closed socket. Did you forget to
573check the return value of your socket() call? See L<perlfunc/bind>.
a0d0e21e 574
c289d2f7
JH
575=item binmode() on closed filehandle %s
576
577(W unopened) You tried binmode() on a filehandle that was never opened.
4dcecea4 578Check your control flow and number of arguments.
c289d2f7 579
c5a0f51a
JH
580=item Bit vector size > 32 non-portable
581
e476b1b5 582(W portable) Using bit vector sizes larger than 32 is non-portable.
c5a0f51a 583
043c750c 584=item Bizarre copy of %s
4633a7c4 585
be771a83 586(P) Perl detected an attempt to copy an internal value that is not
ab830aa0 587copiable.
4633a7c4 588
5a25739d
FC
589=item Bizarre SvTYPE [%d]
590
434f489b 591(P) When starting a new thread or returning values from a thread, Perl
5a25739d
FC
592encountered an invalid data type.
593
b927b7e9 594=item Both or neither range ends should be Unicode in regex; marked by
6e8a73f2 595S<<-- HERE> in m/%s/
b927b7e9
KW
596
597(W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
598
599In a bracketed character class in a regular expression pattern, you
600had a range which has exactly one end of it specified using C<\N{}>, and
601the other end is specified using a non-portable mechanism. Perl treats
602the range as a Unicode range, that is, all the characters in it are
603considered to be the Unicode characters, and which may be different code
604points on some platforms Perl runs on. For example, C<[\N{U+06}-\x08]>
605is treated as if you had instead said C<[\N{U+06}-\N{U+08}]>, that is it
606matches the characters whose code points in Unicode are 6, 7, and 8.
607But that C<\x08> might indicate that you meant something different, so
608the warning gets raised.
609
f675dbe5
CB
610=item Buffer overflow in prime_env_iter: %s
611
be771a83
GS
612(W internal) A warning peculiar to VMS. While Perl was preparing to
613iterate over %ENV, it encountered a logical name or symbol definition
614which was too long, so it was truncated to the string shown.
f675dbe5 615
a0d0e21e
LW
616=item Callback called exit
617
4929bf7b 618(F) A subroutine invoked from an external package via call_sv()
a0d0e21e
LW
619exited by calling exit.
620
6df41af2 621=item %s() called too early to check prototype
f675dbe5 622
be771a83
GS
623(W prototype) You've called a function that has a prototype before the
624parser saw a definition or declaration for it, and Perl could not check
625that the call conforms to the prototype. You need to either add an
626early prototype declaration for the subroutine in question, or move the
627subroutine definition ahead of the call to get proper prototype
628checking. Alternatively, if you are certain that you're calling the
629function correctly, you may put an ampersand before the name to avoid
630the warning. See L<perlsub>.
f675dbe5 631
56feebad
FC
632=item Calling POSIX::%s() is deprecated
633
634(D deprecated) You called a function whose use is deprecated. See
635the function's name in L<POSIX> for details.
636
0c7df902
JH
637=item Cannot chr %f
638
639(F) You passed an invalid number (like an infinity or not-a-number) to C<chr>.
640
5dee29d4 641=item Cannot compress %f in pack
0c7df902 642
5dee29d4
JH
643(F) You tried compressing an infinity or not-a-number as an unsigned
644integer with BER, which makes no sense.
0c7df902 645
49704364 646=item Cannot compress integer in pack
0258719b 647
717feafc
JH
648(F) An argument to pack("w",...) was too large to compress.
649The BER compressed integer format can only be used with positive
650integers, and you attempted to compress a very large number (> 1e308).
651See L<perlfunc/pack>.
0258719b 652
49704364 653=item Cannot compress negative numbers in pack
0258719b
NC
654
655(F) An argument to pack("w",...) was negative. The BER compressed integer
656format can only be used with positive integers. See L<perlfunc/pack>.
657
5c1f4d79
NC
658=item Cannot convert a reference to %s to typeglob
659
6903afa2
FC
660(F) You manipulated Perl's symbol table directly, stored a reference
661in it, then tried to access that symbol via conventional Perl syntax.
662The access triggers Perl to autovivify that typeglob, but it there is
663no legal conversion from that type of reference to a typeglob.
5c1f4d79 664
4040665a 665=item Cannot copy to %s
ba2fdce6
NC
666
667(P) Perl detected an attempt to copy a value to an internal type that cannot
4dcecea4 668be directly assigned to.
ba2fdce6 669
b5d97229
RGS
670=item Cannot find encoding "%s"
671
672(S io) You tried to apply an encoding that did not exist to a filehandle,
673either with open() or binmode().
674
0c7df902
JH
675=item Cannot pack %f with '%c'
676
5dee29d4 677(F) You tried converting an infinity or not-a-number to an integer,
0c7df902
JH
678which makes no sense.
679
680=item Cannot printf %f with '%c'
681
682(F) You tried printing an infinity or not-a-number as a character (%c),
683which makes no sense. Maybe you meant '%s', or just stringifying it?
684
7355df7e
FC
685=item Cannot set tied @DB::args
686
687(F) C<caller> tried to set C<@DB::args>, but found it tied. Tying C<@DB::args>
688is not supported. (Before this error was added, it used to crash.)
689
ce65bc73
FC
690=item Cannot tie unreifiable array
691
692(P) You somehow managed to call C<tie> on an array that does not
693keep a reference count on its arguments and cannot be made to
694do so. Such arrays are not even supposed to be accessible to
695Perl code, but are only used internally.
696
46e58bd2
AC
697=item Cannot yet reorder sv_catpvfn() arguments from va_list
698
699(F) Some XS code tried to use C<sv_catpvfn()> or a related function with a
700format string that specifies explicit indexes for some of the elements, and
701using a C-style variable-argument list (a C<va_list>). This is not currently
702supported. XS authors wanting to do this must instead construct a C array of
703C<SV*> scalars containing the arguments.
704
96ebfdd7
RK
705=item Can only compress unsigned integers in pack
706
707(F) An argument to pack("w",...) was not an integer. The BER compressed
708integer format can only be used with positive integers, and you attempted
709to compress something else. See L<perlfunc/pack>.
710
a0d0e21e
LW
711=item Can't bless non-reference value
712
713(F) Only hard references may be blessed. This is how Perl "enforces"
714encapsulation of objects. See L<perlobj>.
715
dc57907a
RGS
716=item Can't "break" in a loop topicalizer
717
0d863452 718(F) You called C<break>, but you're in a C<foreach> block rather than
6903afa2 719a C<given> block. You probably meant to use C<next> or C<last>.
0d863452
RH
720
721=item Can't "break" outside a given block
dc57907a 722
0d863452
RH
723(F) You called C<break>, but you're not inside a C<given> block.
724
6df41af2
GS
725=item Can't call method "%s" on an undefined value
726
727(F) You used the syntax of a method call, but the slot filled by the
be771a83
GS
728object reference or package name contains an undefined value. Something
729like this will reproduce the error:
6df41af2
GS
730
731 $BADREF = undef;
732 process $BADREF 1,2,3;
733 $BADREF->process(1,2,3);
734
a0d0e21e
LW
735=item Can't call method "%s" on unblessed reference
736
54310121 737(F) A method call must know in what package it's supposed to run. It
be771a83
GS
738ordinarily finds this out from the object reference you supply, but you
739didn't supply an object reference in this case. A reference isn't an
740object reference until it has been blessed. See L<perlobj>.
a0d0e21e
LW
741
742=item Can't call method "%s" without a package or object reference
743
744(F) You used the syntax of a method call, but the slot filled by the
be771a83
GS
745object reference or package name contains an expression that returns a
746defined value which is neither an object reference nor a package name.
72b5445b
GS
747Something like this will reproduce the error:
748
749 $BADREF = 42;
750 process $BADREF 1,2,3;
751 $BADREF->process(1,2,3);
752
dfe378f1
FC
753=item Can't call mro_isa_changed_in() on anonymous symbol table
754
755(P) Perl got confused as to whether a hash was a plain hash or a
756symbol table hash when trying to update @ISA caches.
757
2bf7e7b2
FC
758=item Can't call mro_method_changed_in() on anonymous symbol table
759
760(F) An XS module tried to call C<mro_method_changed_in> on a hash that was
761not attached to the symbol table.
762
a0d0e21e
LW
763=item Can't chdir to %s
764
f703fc96 765(F) You called C<perl -x/foo/bar>, but F</foo/bar> is not a directory
a0d0e21e
LW
766that you can chdir to, possibly because it doesn't exist.
767
0545a864 768=item Can't check filesystem of script "%s" for nosuid
104d25b7 769
be771a83
GS
770(P) For some reason you can't check the filesystem of the script for
771nosuid.
104d25b7 772
22e74366 773=item Can't coerce %s to %s in %s
a0d0e21e
LW
774
775(F) Certain types of SVs, in particular real symbol table entries
55497cff 776(typeglobs), can't be forced to stop being what they are. So you can't
a0d0e21e
LW
777say things like:
778
779 *foo += 1;
780
781You CAN say
782
783 $foo = *foo;
784 $foo += 1;
785
786but then $foo no longer contains a glob.
787
0d863452 788=item Can't "continue" outside a when block
dc57907a 789
0d863452
RH
790(F) You called C<continue>, but you're not inside a C<when>
791or C<default> block.
792
a0d0e21e
LW
793=item Can't create pipe mailbox
794
be771a83
GS
795(P) An error peculiar to VMS. The process is suffering from exhausted
796quotas or other plumbing problems.
a0d0e21e 797
eb64745e
GS
798=item Can't declare %s in "%s"
799
30c282f6
NC
800(F) Only scalar, array, and hash variables may be declared as "my", "our" or
801"state" variables. They must have ordinary identifiers as names.
a0d0e21e 802
fc7debfb
FC
803=item Can't "default" outside a topicalizer
804
805(F) You have used a C<default> block that is neither inside a
806C<foreach> loop nor a C<given> block. (Note that this error is
807issued on exit from the C<default> block, so you won't get the
808error if you use an explicit C<continue>.)
809
a2162cd9
FC
810=item Can't do inplace edit: %s is not a regular file
811
812(S inplace) You tried to use the B<-i> switch on a special file, such as
813a file in /dev, a FIFO or an uneditable directory. The file was ignored.
814
815=item Can't do inplace edit on %s: %s
816
817(S inplace) The creation of the new file failed for the indicated
818reason.
819
820=item Can't do inplace edit without backup
821
822(F) You're on a system such as MS-DOS that gets confused if you try
823reading from a deleted (but still opened) file. You have to say
824C<-i.bak>, or some such.
825
826=item Can't do inplace edit: %s would not be unique
827
828(S inplace) Your filesystem does not support filenames longer than 14
829characters and Perl was unable to create a unique filename during
830inplace editing with the B<-i> switch. The file was ignored.
831
ab0b796c
KW
832=item Can't do %s("%s") on non-UTF-8 locale; resolved to "%s".
833
834(W locale) You are 1) running under "C<use locale>"; 2) the current
835locale is not a UTF-8 one; 3) you tried to do the designated case-change
836operation on the specified Unicode character; and 4) the result of this
837operation would mix Unicode and locale rules, which likely conflict.
838Mixing of different rule types is forbidden, so the operation was not
839done; instead the result is the indicated value, which is the best
840available that uses entirely Unicode rules. That turns out to almost
841always be the original character, unchanged.
842
843It is generally a bad idea to mix non-UTF-8 locales and Unicode, and
844this issue is one of the reasons why. This warning is raised when
845Unicode rules would normally cause the result of this operation to
846contain a character that is in the range specified by the locale,
8470..255, and hence is subject to the locale's rules, not Unicode's.
848
849If you are using locale purely for its characteristics related to things
850like its numeric and time formatting (and not C<LC_CTYPE>), consider
851using a restricted form of the locale pragma (see L<perllocale/The "use
852locale" pragma>) like "S<C<use locale ':not_characters'>>".
853
854Note that failed case-changing operations done as a result of
855case-insensitive C</i> regular expression matching will show up in this
856warning as having the C<fc> operation (as that is what the regular
857expression engine calls behind the scenes.)
858
a0d0e21e
LW
859=item Can't do waitpid with flags
860
be771a83
GS
861(F) This machine doesn't have either waitpid() or wait4(), so only
862waitpid() without flags is emulated.
a0d0e21e 863
a0d0e21e
LW
864=item Can't emulate -%s on #! line
865
be771a83
GS
866(F) The #! line specifies a switch that doesn't make sense at this
867point. For example, it'd be kind of silly to put a B<-x> on the #!
868line.
a0d0e21e 869
1109a392
MHM
870=item Can't %s %s-endian %ss on this platform
871
872(F) Your platform's byte-order is neither big-endian nor little-endian,
873or it has a very strange pointer size. Packing and unpacking big- or
874little-endian floating point values and pointers may not be possible.
875See L<perlfunc/pack>.
876
a0d0e21e
LW
877=item Can't exec "%s": %s
878
d1be9408 879(W exec) A system(), exec(), or piped open call could not execute the
be771a83
GS
880named program for the indicated reason. Typical reasons include: the
881permissions were wrong on the file, the file wasn't found in
882C<$ENV{PATH}>, the executable in question was compiled for another
883architecture, or the #! line in a script points to an interpreter that
884can't be run for similar reasons. (Or maybe your system doesn't support
885#! at all.)
a0d0e21e
LW
886
887=item Can't exec %s
888
be771a83
GS
889(F) Perl was trying to execute the indicated program for you because
890that's what the #! line said. If that's not what you wanted, you may
891need to mention "perl" on the #! line somewhere.
a0d0e21e
LW
892
893=item Can't execute %s
894
be771a83
GS
895(F) You used the B<-S> switch, but the copies of the script to execute
896found in the PATH did not have correct permissions.
2a92aaa0 897
6df41af2 898=item Can't find an opnumber for "%s"
2a92aaa0 899
be771a83
GS
900(F) A string of a form C<CORE::word> was given to prototype(), but there
901is no builtin with the name C<word>.
6df41af2
GS
902
903=item Can't find label %s
904
be771a83
GS
905(F) You said to goto a label that isn't mentioned anywhere that it's
906possible for us to go to. See L<perlfunc/goto>.
2a92aaa0
GS
907
908=item Can't find %s on PATH
909
be771a83
GS
910(F) You used the B<-S> switch, but the script to execute could not be
911found in the PATH.
a0d0e21e 912
6df41af2 913=item Can't find %s on PATH, '.' not in PATH
a0d0e21e 914
be771a83
GS
915(F) You used the B<-S> switch, but the script to execute could not be
916found in the PATH, or at least not with the correct permissions. The
917script exists in the current directory, but PATH prohibits running it.
a0d0e21e
LW
918
919=item Can't find string terminator %s anywhere before EOF
920
be771a83
GS
921(F) Perl strings can stretch over multiple lines. This message means
922that the closing delimiter was omitted. Because bracketed quotes count
923nesting levels, the following is missing its final parenthesis:
a0d0e21e 924
fb73857a
PP
925 print q(The character '(' starts a side comment.);
926
97b3d10f 927If you're getting this error from a here-document, you may have
b6b8cb97
FC
928included unseen whitespace before or after your closing tag or there
929may not be a linebreak after it. A good programmer's editor will have
930a way to help you find these characters (or lack of characters). See
931L<perlop> for the full details on here-documents.
a0d0e21e 932
660a4616
ST
933=item Can't find Unicode property definition "%s"
934
29f52644
KW
935=item Can't find Unicode property definition "%s" in regex; marked by <-- HERE in m/%s/
936
937(F) The named property which you specified via C<\p> or C<\P> is not one
938known to Perl. Perhaps you misspelled the name? See
e1b711da 939L<perluniprops/Properties accessible through \p{} and \P{}>
29f52644
KW
940for a complete list of available official
941properties. If it is a
942L<user-defined property|perlunicode/User-Defined Character Properties>
943it must have been defined by the time the regular expression is
944matched.
945
946If you didn't mean to use a Unicode property, escape the C<\p>, either
947by C<\\p> (just the C<\p>) or by C<\Q\p> (the rest of the string, or
5f8ad6b6 948until C<\E>).
660a4616 949
b3647a36 950=item Can't fork: %s
a0d0e21e 951
be771a83
GS
952(F) A fatal error occurred while trying to fork while opening a
953pipeline.
a0d0e21e 954
b3647a36
SR
955=item Can't fork, trying again in 5 seconds
956
c973c02e 957(W pipe) A fork in a piped open failed with EAGAIN and will be retried
b3647a36
SR
958after five seconds.
959
748a9306
LW
960=item Can't get filespec - stale stat buffer?
961
be771a83
GS
962(S) A warning peculiar to VMS. This arises because of the difference
963between access checks under VMS and under the Unix model Perl assumes.
964Under VMS, access checks are done by filename, rather than by bits in
965the stat buffer, so that ACLs and other protections can be taken into
966account. Unfortunately, Perl assumes that the stat buffer contains all
967the necessary information, and passes it, instead of the filespec, to
2fe2bdfd 968the access-checking routine. It will try to retrieve the filespec using
be771a83
GS
969the device name and FID present in the stat buffer, but this works only
970if you haven't made a subsequent call to the CRTL stat() routine,
971because the device name is overwritten with each call. If this warning
2fe2bdfd
FC
972appears, the name lookup failed, and the access-checking routine gave up
973and returned FALSE, just to be conservative. (Note: The access-checking
be771a83
GS
974routine knows about the Perl C<stat> operator and file tests, so you
975shouldn't ever see this warning in response to a Perl command; it arises
976only if some internal code takes stat buffers lightly.)
748a9306 977
a0d0e21e
LW
978=item Can't get pipe mailbox device name
979
be771a83
GS
980(P) An error peculiar to VMS. After creating a mailbox to act as a
981pipe, Perl can't retrieve its name for later use.
a0d0e21e
LW
982
983=item Can't get SYSGEN parameter value for MAXBUF
984
748a9306
LW
985(P) An error peculiar to VMS. Perl asked $GETSYI how big you want your
986mailbox buffers to be, and didn't get an answer.
a0d0e21e 987
6df41af2 988=item Can't "goto" into the middle of a foreach loop
a0d0e21e 989
be771a83
GS
990(F) A "goto" statement was executed to jump into the middle of a foreach
991loop. You can't get there from here. See L<perlfunc/goto>.
6df41af2
GS
992
993=item Can't "goto" out of a pseudo block
994
be771a83
GS
995(F) A "goto" statement was executed to jump out of what might look like
996a block, except that it isn't a proper block. This usually occurs if
997you tried to jump out of a sort() block or subroutine, which is a no-no.
998See L<perlfunc/goto>.
a0d0e21e 999
5a25739d
FC
1000=item Can't goto subroutine from an eval-%s
1001
1002(F) The "goto subroutine" call can't be used to jump out of an eval
1003"string" or block.
1004
9850bf21 1005=item Can't goto subroutine from a sort sub (or similar callback)
cd299c6e 1006
9850bf21
RH
1007(F) The "goto subroutine" call can't be used to jump out of the
1008comparison sub for a sort(), or from a similar callback (such
1009as the reduce() function in List::Util).
1010
6df41af2
GS
1011=item Can't goto subroutine outside a subroutine
1012
be771a83
GS
1013(F) The deeply magical "goto subroutine" call can only replace one
1014subroutine call for another. It can't manufacture one out of whole
1015cloth. In general you should be calling it out of only an AUTOLOAD
1016routine anyway. See L<perlfunc/goto>.
6df41af2 1017
0b5b802d
GS
1018=item Can't ignore signal CHLD, forcing to default
1019
be771a83
GS
1020(W signal) Perl has detected that it is being run with the SIGCHLD
1021signal (sometimes known as SIGCLD) disabled. Since disabling this
1022signal will interfere with proper determination of exit status of child
1023processes, Perl has reset the signal to its default value. This
1024situation typically indicates that the parent program under which Perl
1025may be running (e.g. cron) is being very careless.
0b5b802d 1026
e2c0f81f
DG
1027=item Can't kill a non-numeric process ID
1028
1029(F) Process identifiers must be (signed) integers. It is a fatal error to
1030attempt to kill() an undefined, empty-string or otherwise non-numeric
1031process identifier.
1032
6df41af2 1033=item Can't "last" outside a loop block
4633a7c4 1034
6df41af2 1035(F) A "last" statement was executed to break out of the current block,
be771a83
GS
1036except that there's this itty bitty problem called there isn't a current
1037block. Note that an "if" or "else" block doesn't count as a "loopish"
1038block, as doesn't a block given to sort(), map() or grep(). You can
1039usually double the curlies to get the same effect though, because the
1040inner curlies will be considered a block that loops once. See
1041L<perlfunc/last>.
4633a7c4 1042
2c7d6b9c
RGS
1043=item Can't linearize anonymous symbol table
1044
1045(F) Perl tried to calculate the method resolution order (MRO) of a
1046package, but failed because the package stash has no name.
1047
b8170e59
JB
1048=item Can't load '%s' for module %s
1049
6903afa2
FC
1050(F) The module you tried to load failed to load a dynamic extension.
1051This may either mean that you upgraded your version of perl to one
1052that is incompatible with your old dynamic extensions (which is known
1053to happen between major versions of perl), or (more likely) that your
1054dynamic extension was built against an older version of the library
1055that is installed on your system. You may need to rebuild your old
1056dynamic extensions.
b8170e59 1057
748a9306
LW
1058=item Can't localize lexical variable %s
1059
2ba9eb46 1060(F) You used local on a variable name that was previously declared as a
b7e4ecc1
FC
1061lexical variable using "my" or "state". This is not allowed. If you
1062want to localize a package variable of the same name, qualify it with
1063the package name.
748a9306 1064
6df41af2 1065=item Can't localize through a reference
4727527e 1066
6df41af2
GS
1067(F) You said something like C<local $$ref>, which Perl can't currently
1068handle, because when it goes to restore the old value of whatever $ref
be771a83 1069pointed to after the scope of the local() is finished, it can't be sure
64977eb6 1070that $ref will still be a reference.
4727527e 1071
ea071790 1072=item Can't locate %s
ec889f3a 1073
fa816bf3
FC
1074(F) You said to C<do> (or C<require>, or C<use>) a file that couldn't be found.
1075Perl looks for the file in all the locations mentioned in @INC, unless
1076the file name included the full path to the file. Perhaps you need
1077to set the PERL5LIB or PERL5OPT environment variable to say where the
1078extra library is, or maybe the script needs to add the library name
be771a83
GS
1079to @INC. Or maybe you just misspelled the name of the file. See
1080L<perlfunc/require> and L<lib>.
a0d0e21e 1081
6df41af2
GS
1082=item Can't locate auto/%s.al in @INC
1083
be771a83
GS
1084(F) A function (or method) was called in a package which allows
1085autoload, but there is no function to autoload. Most probable causes
1086are a misprint in a function/method name or a failure to C<AutoSplit>
1087the file, say, by doing C<make install>.
6df41af2 1088
b8170e59
JB
1089=item Can't locate loadable object for module %s in @INC
1090
1091(F) The module you loaded is trying to load an external library, like
d70d8e57 1092for example, F<foo.so> or F<bar.dll>, but the L<DynaLoader> module was
b8170e59
JB
1093unable to locate this library. See L<DynaLoader>.
1094
a0d0e21e
LW
1095=item Can't locate object method "%s" via package "%s"
1096
1097(F) You called a method correctly, and it correctly indicated a package
1098functioning as a class, but that package doesn't define that particular
2ba9eb46 1099method, nor does any of its base classes. See L<perlobj>.
a0d0e21e 1100
8af56b9d
FC
1101=item Can't locate object method "%s" via package "%s" (perhaps you forgot
1102to load "%s"?)
1103
1104(F) You called a method on a class that did not exist, and the method
1105could not be found in UNIVERSAL. This often means that a method
1106requires a package that has not been loaded.
1107
a0d0e21e
LW
1108=item Can't locate package %s for @%s::ISA
1109
be771a83
GS
1110(W syntax) The @ISA array contained the name of another package that
1111doesn't seem to exist.
a0d0e21e 1112
2f7da168
RK
1113=item Can't locate PerlIO%s
1114
1115(F) You tried to use in open() a PerlIO layer that does not exist,
1116e.g. open(FH, ">:nosuchlayer", "somefile").
1117
f4ad53f4 1118=item Can't make list assignment to %ENV on this system
3e3baf6d 1119
be771a83
GS
1120(F) List assignment to %ENV is not supported on some systems, notably
1121VMS.
3e3baf6d 1122
cd40cd58
NC
1123=item Can't make loaded symbols global on this platform while loading %s
1124
ff9c1ae8 1125(S) A module passed the flag 0x01 to DynaLoader::dl_load_file() to request
cd40cd58
NC
1126that symbols from the stated file are made available globally within the
1127process, but that functionality is not available on this platform. Whilst
1128the module likely will still work, this may prevent the perl interpreter
1129from loading other XS-based extensions which need to link directly to
1130functions defined in the C or XS code in the stated file.
1131
a0d0e21e
LW
1132=item Can't modify %s in %s
1133
be771a83
GS
1134(F) You aren't allowed to assign to the item indicated, or otherwise try
1135to change it, such as with an auto-increment.
a0d0e21e 1136
54310121 1137=item Can't modify nonexistent substring
a0d0e21e
LW
1138
1139(P) The internal routine that does assignment to a substr() was handed
1140a NULL.
1141
0f948285 1142=item Can't modify non-lvalue subroutine call of &%s
6df41af2
GS
1143
1144(F) Subroutines meant to be used in lvalue context should be declared as
2fe2bdfd 1145such. See L<perlsub/"Lvalue subroutines">.
6df41af2 1146
cf6e1fa1
FC
1147=item Can't modify reference to %s in %s assignment
1148
1149(F) Only a limited number of constructs can be used as the argument to a
1150reference constructor on the left-hand side of an assignment, and what
1151you used was not one of them. See L<perlref/Assigning to References>.
1152
1153=item Can't modify reference to localized parenthesized array in list
1154assignment
1155
1156(F) Assigning to C<\local(@array)> or C<\(local @array)> is not supported, as
1157it is not clear exactly what it should do. If you meant to make @array
1158refer to some other array, use C<\@array = \@other_array>. If you want to
1159make the elements of @array aliases of the scalars referenced on the
1160right-hand side, use C<\(@array) = @scalar_refs>.
1161
1162=item Can't modify reference to parenthesized hash in list assignment
1163
1164(F) Assigning to C<\(%hash)> is not supported. If you meant to make %hash
1165refer to some other hash, use C<\%hash = \%other_hash>. If you want to
1166make the elements of %hash into aliases of the scalars referenced on the
1167right-hand side, use a hash slice: C<\@hash{@keys} = @those_scalar_refs>.
1168
5f05dabc 1169=item Can't msgrcv to read-only var
a0d0e21e 1170
5f05dabc 1171(F) The target of a msgrcv must be modifiable to be used as a receive
a0d0e21e
LW
1172buffer.
1173
6df41af2
GS
1174=item Can't "next" outside a loop block
1175
1176(F) A "next" statement was executed to reiterate the current block, but
1177there isn't a current block. Note that an "if" or "else" block doesn't
be771a83
GS
1178count as a "loopish" block, as doesn't a block given to sort(), map() or
1179grep(). You can usually double the curlies to get the same effect
1180though, because the inner curlies will be considered a block that loops
1181once. See L<perlfunc/next>.
6df41af2 1182
a0d0e21e
LW
1183=item Can't open %s: %s
1184
c47ff5f1 1185(S inplace) The implicit opening of a file through use of the C<< <> >>
08e9d68e 1186filehandle, either implicitly under the C<-n> or C<-p> command-line
46fa9b26
FC
1187switches, or explicitly, failed for the indicated reason. Usually
1188this is because you don't have read permission for a file which
1189you named on the command line.
1190
1191(F) You tried to call perl with the B<-e> switch, but F</dev/null> (or
1192your operating system's equivalent) could not be opened.
a0d0e21e 1193
9a869a14
RGS
1194=item Can't open a reference
1195
1196(W io) You tried to open a scalar reference for reading or writing,
2fe2bdfd 1197using the 3-arg open() syntax:
9a869a14
RGS
1198
1199 open FH, '>', $ref;
1200
1201but your version of perl is compiled without perlio, and this form of
1202open is not supported.
1203
a0d0e21e
LW
1204=item Can't open bidirectional pipe
1205
be771a83
GS
1206(W pipe) You tried to say C<open(CMD, "|cmd|")>, which is not supported.
1207You can try any of several modules in the Perl library to do this, such
1208as IPC::Open2. Alternately, direct the pipe's output to a file using
1209">", and then read it in under a different file handle.
a0d0e21e 1210
748a9306
LW
1211=item Can't open error file %s as stderr
1212
be771a83
GS
1213(F) An error peculiar to VMS. Perl does its own command line
1214redirection, and couldn't open the file specified after '2>' or '2>>' on
1215the command line for writing.
748a9306
LW
1216
1217=item Can't open input file %s as stdin
1218
be771a83
GS
1219(F) An error peculiar to VMS. Perl does its own command line
1220redirection, and couldn't open the file specified after '<' on the
1221command line for reading.
748a9306
LW
1222
1223=item Can't open output file %s as stdout
1224
be771a83
GS
1225(F) An error peculiar to VMS. Perl does its own command line
1226redirection, and couldn't open the file specified after '>' or '>>' on
1227the command line for writing.
748a9306
LW
1228
1229=item Can't open output pipe (name: %s)
1230
be771a83
GS
1231(P) An error peculiar to VMS. Perl does its own command line
1232redirection, and couldn't open the pipe into which to send data destined
1233for stdout.
748a9306 1234
3b1cf97d 1235=item Can't open perl script "%s": %s
a0d0e21e
LW
1236
1237(F) The script you specified can't be opened for the indicated reason.
1238
fa3aa65a
JC
1239If you're debugging a script that uses #!, and normally relies on the
1240shell's $PATH search, the -S option causes perl to do that search, so
1241you don't have to type the path or C<`which $scriptname`>.
1242
6df41af2
GS
1243=item Can't read CRTL environ
1244
1245(S) A warning peculiar to VMS. Perl tried to read an element of %ENV
1246from the CRTL's internal environment array and discovered the array was
1247missing. You need to figure out where your CRTL misplaced its environ
be771a83
GS
1248or define F<PERL_ENV_TABLES> (see L<perlvms>) so that environ is not
1249searched.
6df41af2 1250
f3106bc8
LM
1251=item Can't redeclare "%s" in "%s"
1252
1253(F) A "my", "our" or "state" declaration was found within another declaration,
1254such as C<my ($x, my($y), $z)> or C<our (my $x)>.
1255
6df41af2
GS
1256=item Can't "redo" outside a loop block
1257
1258(F) A "redo" statement was executed to restart the current block, but
1259there isn't a current block. Note that an "if" or "else" block doesn't
1260count as a "loopish" block, as doesn't a block given to sort(), map()
1261or grep(). You can usually double the curlies to get the same effect
1262though, because the inner curlies will be considered a block that
1263loops once. See L<perlfunc/redo>.
1264
64977eb6 1265=item Can't remove %s: %s, skipping file
10f9c03d 1266
be771a83
GS
1267(S inplace) You requested an inplace edit without creating a backup
1268file. Perl was unable to remove the original file to replace it with
1269the modified file. The file was left unmodified.
10f9c03d 1270
a0d0e21e
LW
1271=item Can't rename %s to %s: %s, skipping file
1272
e476b1b5 1273(S inplace) The rename done by the B<-i> switch failed for some reason,
10f9c03d 1274probably because you don't have write permission to the directory.
a0d0e21e 1275
748a9306
LW
1276=item Can't reopen input pipe (name: %s) in binary mode
1277
be771a83
GS
1278(P) An error peculiar to VMS. Perl thought stdin was a pipe, and tried
1279to reopen it to accept binary data. Alas, it failed.
748a9306 1280
9415f659
KW
1281=item Can't represent character for Ox%X on this platform
1282
1283(F) There is a hard limit to how big a character code point can be due
1284to the fundamental properties of UTF-8, especially on EBCDIC
1285platforms. The given code point exceeds that. The only work-around is
1286to not use such a large code point.
1287
4f12ec0e
FC
1288=item Can't reset %ENV on this system
1289
1290(F) You called C<reset('E')> or similar, which tried to reset
1291all variables in the current package beginning with "E". In
1292the main package, that includes %ENV. Resetting %ENV is not
1293supported on some systems, notably VMS.
1294
fe13d51d 1295=item Can't resolve method "%s" overloading "%s" in package "%s"
6df41af2 1296
1fa582fa
FC
1297(F)(P) Error resolving overloading specified by a method name (as
1298opposed to a subroutine reference): no such method callable via the
1299package. If the method name is C<???>, this is an internal error.
6df41af2 1300
cd06dffe
GS
1301=item Can't return %s from lvalue subroutine
1302
be771a83
GS
1303(F) Perl detected an attempt to return illegal lvalues (such as
1304temporary or readonly values) from a subroutine used as an lvalue. This
1305is not allowed.
cd06dffe 1306
96ebfdd7
RK
1307=item Can't return outside a subroutine
1308
1309(F) The return statement was executed in mainline code, that is, where
1310there was no subroutine call to return out of. See L<perlsub>.
1311
78f9721b
SM
1312=item Can't return %s to lvalue scalar context
1313
6903afa2
FC
1314(F) You tried to return a complete array or hash from an lvalue
1315subroutine, but you called the subroutine in a way that made Perl
1316think you meant to return only one value. You probably meant to
1317write parentheses around the call to the subroutine, which tell
1318Perl that the call should be in list context.
78f9721b 1319
a0d0e21e
LW
1320=item Can't stat script "%s"
1321
be771a83
GS
1322(P) For some reason you can't fstat() the script even though you have it
1323open already. Bizarre.
a0d0e21e 1324
a0d0e21e
LW
1325=item Can't take log of %g
1326
fb73857a 1327(F) For ordinary real numbers, you can't take the logarithm of a
6903afa2 1328negative number or zero. There's a Math::Complex package that comes
be771a83
GS
1329standard with Perl, though, if you really want to do that for the
1330negative numbers.
a0d0e21e
LW
1331
1332=item Can't take sqrt of %g
1333
1334(F) For ordinary real numbers, you can't take the square root of a
fb73857a
PP
1335negative number. There's a Math::Complex package that comes standard
1336with Perl, though, if you really want to do that.
a0d0e21e
LW
1337
1338=item Can't undef active subroutine
1339
1340(F) You can't undefine a routine that's currently running. You can,
1341however, redefine it while it's running, and you can even undef the
1342redefined subroutine while the old routine is running. Go figure.
1343
c81225bc 1344=item Can't upgrade %s (%d) to %d
a0d0e21e 1345
be771a83
GS
1346(P) The internal sv_upgrade routine adds "members" to an SV, making it
1347into a more specialized kind of SV. The top several SV types are so
1348specialized, however, that they cannot be interconverted. This message
1349indicates that such a conversion was attempted.
a0d0e21e 1350
6651ba0b
FC
1351=item Can't use '%c' after -mname
1352
1353(F) You tried to call perl with the B<-m> switch, but you put something
1354other than "=" after the module name.
1355
1f1ec7b5
KW
1356=item Can't use a hash as a reference
1357
1358(F) You tried to use a hash as a reference, as in
66a1f5ec
FC
1359C<< %foo->{"bar"} >> or C<< %$ref->{"hello"} >>. Versions of perl
1360<= 5.22.0 used to allow this syntax, but shouldn't
1361have. This was deprecated in perl 5.6.1.
1f1ec7b5
KW
1362
1363=item Can't use an array as a reference
1364
1365(F) You tried to use an array as a reference, as in
66a1f5ec
FC
1366C<< @foo->[23] >> or C<< @$ref->[99] >>. Versions of perl <= 5.22.0
1367used to allow this syntax, but shouldn't have. This
1368was deprecated in perl 5.6.1.
1f1ec7b5 1369
1db89ea5
BS
1370=item Can't use anonymous symbol table for method lookup
1371
e27ad1f2 1372(F) The internal routine that does method lookup was handed a symbol
1db89ea5
BS
1373table that doesn't have a name. Symbol tables can become anonymous
1374for example by undefining stashes: C<undef %Some::Package::>.
1375
96ebfdd7
RK
1376=item Can't use an undefined value as %s reference
1377
1378(F) A value used as either a hard reference or a symbolic reference must
1379be a defined value. This helps to delurk some insidious errors.
1380
6df41af2
GS
1381=item Can't use bareword ("%s") as %s ref while "strict refs" in use
1382
be771a83
GS
1383(F) Only hard references are allowed by "strict refs". Symbolic
1384references are disallowed. See L<perlref>.
6df41af2 1385
90b75b61 1386=item Can't use %! because Errno.pm is not available
1d2dff63 1387
20561843 1388(F) The first time the C<%!> hash is used, perl automatically loads the
6903afa2 1389Errno.pm module. The Errno module is expected to tie the %! hash to
1d2dff63
GS
1390provide symbolic names for C<$!> errno values.
1391
1109a392
MHM
1392=item Can't use both '<' and '>' after type '%c' in %s
1393
1394(F) A type cannot be forced to have both big-endian and little-endian
1395byte-order at the same time, so this combination of modifiers is not
1396allowed. See L<perlfunc/pack>.
1397
e35475de
KW
1398=item Can't use 'defined(@array)' (Maybe you should just omit the defined()?)
1399
1400(F) defined() is not useful on arrays because it
1401checks for an undefined I<scalar> value. If you want to see if the
1402array is empty, just use C<if (@array) { # not empty }> for example.
1403
1404=item Can't use 'defined(%hash)' (Maybe you should just omit the defined()?)
1405
1406(F) C<defined()> is not usually right on hashes.
1407
1408Although C<defined %hash> is false on a plain not-yet-used hash, it
1409becomes true in several non-obvious circumstances, including iterators,
1410weak references, stash names, even remaining true after C<undef %hash>.
1411These things make C<defined %hash> fairly useless in practice, so it now
1412generates a fatal error.
1413
1414If a check for non-empty is what you wanted then just put it in boolean
1415context (see L<perldata/Scalar values>):
1416
1417 if (%hash) {
1418 # not empty
1419 }
1420
1421If you had C<defined %Foo::Bar::QUUX> to check whether such a package
1422variable exists then that's never really been reliable, and isn't
1423a good way to enquire about the features of a package, or whether
1424it's loaded, etc.
1425
6df41af2
GS
1426=item Can't use %s for loop variable
1427
c1f06047 1428(P) The parser got confused when trying to parse a C<foreach> loop.
6df41af2 1429
aab6a793 1430=item Can't use global %s in "%s"
6df41af2 1431
be771a83
GS
1432(F) You tried to declare a magical variable as a lexical variable. This
1433is not allowed, because the magic can be tied to only one location
1434(namely the global variable) and it would be incredibly confusing to
1435have variables in your program that looked like magical variables but
6df41af2
GS
1436weren't.
1437
6d3b25aa
RGS
1438=item Can't use '%c' in a group with different byte-order in %s
1439
1440(F) You attempted to force a different byte-order on a type
1441that is already inside a group with a byte-order modifier.
1442For example you cannot force little-endianness on a type that
1443is inside a big-endian group.
1444
c07a80fd
PP
1445=item Can't use "my %s" in sort comparison
1446
1447(F) The global variables $a and $b are reserved for sort comparisons.
c47ff5f1 1448You mentioned $a or $b in the same line as the <=> or cmp operator,
c07a80fd
PP
1449and the variable had earlier been declared as a lexical variable.
1450Either qualify the sort variable with the package name, or rename the
1451lexical variable.
1452
a0d0e21e
LW
1453=item Can't use %s ref as %s ref
1454
1455(F) You've mixed up your reference types. You have to dereference a
1456reference of the type needed. You can use the ref() function to
1457test the type of the reference, if need be.
1458
748a9306 1459=item Can't use string ("%s") as %s ref while "strict refs" in use
a0d0e21e 1460
5e634d20
FC
1461=item Can't use string ("%s"...) as %s ref while "strict refs" in use
1462
b41bf23f
FC
1463(F) You've told Perl to dereference a string, something which
1464C<use strict> blocks to prevent it happening accidentally. See
1465L<perlref/"Symbolic references">. This can be triggered by an C<@> or C<$>
1466in a double-quoted string immediately before interpolating a variable,
1467for example in C<"user @$twitter_id">, which says to treat the contents
1468of C<$twitter_id> as an array reference; use a C<\> to have a literal C<@>
1469symbol followed by the contents of C<$twitter_id>: C<"user \@$twitter_id">.
a0d0e21e 1470
748a9306
LW
1471=item Can't use subscript on %s
1472
1473(F) The compiler tried to interpret a bracketed expression as a
1474subscript. But to the left of the brackets was an expression that
209e7cf1 1475didn't look like a hash or array reference, or anything else subscriptable.
748a9306 1476
6df41af2
GS
1477=item Can't use \%c to mean $%c in expression
1478
75b44862
GS
1479(W syntax) In an ordinary expression, backslash is a unary operator that
1480creates a reference to its argument. The use of backslash to indicate a
1481backreference to a matched substring is valid only as part of a regular
be771a83
GS
1482expression pattern. Trying to do this in ordinary Perl code produces a
1483value that prints out looking like SCALAR(0xdecaf). Use the $1 form
1484instead.
6df41af2 1485
810b8aa5
GS
1486=item Can't weaken a nonreference
1487
1488(F) You attempted to weaken something that was not a reference. Only
1489references can be weakened.
1490
fc7debfb
FC
1491=item Can't "when" outside a topicalizer
1492
1493(F) You have used a when() block that is neither inside a C<foreach>
1494loop nor a C<given> block. (Note that this error is issued on exit
1495from the C<when> block, so you won't get the error if the match fails,
1496or if you use an explicit C<continue>.)
1497
5f05dabc 1498=item Can't x= to read-only value
a0d0e21e 1499
be771a83
GS
1500(F) You tried to repeat a constant value (often the undefined value)
1501with an assignment operator, which implies modifying the value itself.
a0d0e21e
LW
1502Perhaps you need to copy the value to a temporary, and repeat that.
1503
a04e6aad 1504=item Character following "\c" must be printable ASCII
f9d13529 1505
7357bd17 1506(F) In C<\cI<X>>, I<X> must be a printable (non-control) ASCII character.
17a3df4c 1507
727b6379 1508Note that ASCII characters that don't map to control characters are
7357bd17 1509discouraged, and will generate the warning (when enabled)
727b6379 1510L</""\c%c" is more clearly written simply as "%s"">.
f9d13529 1511
163a633c
KW
1512=item Character following \%c must be '{' or a single-character Unicode property name in regex; marked by <-- HERE in m/%s/
1513
1514(F) (In the above the C<%c> is replaced by either C<p> or C<P>.) You
1515specified something that isn't a legal Unicode property name. Most
1516Unicode properties are specified by C<\p{...}>. But if the name is a
1517single character one, the braces may be omitted.
1518
f337b084 1519=item Character in 'C' format wrapped in pack
ac7cd81a
SC
1520
1521(W pack) You said
1522
1523 pack("C", $x)
1524
1525where $x is either less than 0 or more than 255; the C<"C"> format is
1526only for encoding native operating system characters (ASCII, EBCDIC,
1527and so on) and not for Unicode characters, so Perl behaved as if you meant
1528
1529 pack("C", $x & 255)
1530
1531If you actually want to pack Unicode codepoints, use the C<"U"> format
1532instead.
1533
f337b084 1534=item Character in 'c' format wrapped in pack
ac7cd81a
SC
1535
1536(W pack) You said
1537
1538 pack("c", $x)
1539
1540where $x is either less than -128 or more than 127; the C<"c"> format
1541is only for encoding native operating system characters (ASCII, EBCDIC,
1542and so on) and not for Unicode characters, so Perl behaved as if you meant
1543
1544 pack("c", $x & 255);
1545
1546If you actually want to pack Unicode codepoints, use the C<"U"> format
1547instead.
1548
f337b084
TH
1549=item Character in '%c' format wrapped in unpack
1550
1551(W unpack) You tried something like
1552
1553 unpack("H", "\x{2a1}")
1554
1a147d38 1555where the format expects to process a byte (a character with a value
6903afa2
FC
1556below 256), but a higher value was provided instead. Perl uses the
1557value modulus 256 instead, as if you had provided:
f337b084
TH
1558
1559 unpack("H", "\x{a1}")
1560
5a25739d
FC
1561=item Character in 'W' format wrapped in pack
1562
1563(W pack) You said
1564
1565 pack("U0W", $x)
1566
1567where $x is either less than 0 or more than 255. However, C<U0>-mode
1568expects all values to fall in the interval [0, 255], so Perl behaved
1569as if you meant:
1570
1571 pack("U0W", $x & 255)
1572
f337b084
TH
1573=item Character(s) in '%c' format wrapped in pack
1574
1575(W pack) You tried something like
1576
1577 pack("u", "\x{1f3}b")
1578
1a147d38 1579where the format expects to process a sequence of bytes (character with a
6903afa2 1580value below 256), but some of the characters had a higher value. Perl
f337b084
TH
1581uses the character values modulus 256 instead, as if you had provided:
1582
1583 pack("u", "\x{f3}b")
1584
1585=item Character(s) in '%c' format wrapped in unpack
1586
1587(W unpack) You tried something like
1588
1589 unpack("s", "\x{1f3}b")
1590
1a147d38 1591where the format expects to process a sequence of bytes (character with a
6903afa2 1592value below 256), but some of the characters had a higher value. Perl
f337b084
TH
1593uses the character values modulus 256 instead, as if you had provided:
1594
1595 unpack("s", "\x{f3}b")
1596
f51551f7
FC
1597=item charnames alias definitions may not contain a sequence of multiple spaces
1598
1599(F) You defined a character name which had multiple space characters
1600in a row. Change them to single spaces. Usually these names are
1601defined in the C<:alias> import argument to C<use charnames>, but they
1602could be defined by a translator installed into C<$^H{charnames}>. See
1603L<charnames/CUSTOM ALIASES>.
1604
1605=item charnames alias definitions may not contain trailing white-space
1606
1607(F) You defined a character name which ended in a space
1608character. Remove the trailing space(s). Usually these names are
1609defined in the C<:alias> import argument to C<use charnames>, but they
1610could be defined by a translator installed into C<$^H{charnames}>.
1611See L<charnames/CUSTOM ALIASES>.
1612
60121127
TC
1613=item chdir() on unopened filehandle %s
1614
1615(W unopened) You tried chdir() on a filehandle that was never opened.
1616
f866a7cd
FC
1617=item "\c%c" is more clearly written simply as "%s"
1618
1619(W syntax) The C<\cI<X>> construct is intended to be a way to specify
7ed0dd93
FC
1620non-printable characters. You used it for a printable one, which
1621is better written as simply itself, perhaps preceded by a backslash
1622for non-word characters. Doing it the way you did is not portable
1623between ASCII and EBCDIC platforms.
f866a7cd 1624
6651ba0b
FC
1625=item Cloning substitution context is unimplemented
1626
1627(F) Creating a new thread inside the C<s///> operator is not supported.
1628
abc7ecad
SP
1629=item closedir() attempted on invalid dirhandle %s
1630
1631(W io) The dirhandle you tried to close is either closed or not really
1632a dirhandle. Check your control flow.
1633
5a25739d
FC
1634=item close() on unopened filehandle %s
1635
1636(W unopened) You tried to close a filehandle that was never opened.
1637
541ed3a9
FC
1638=item Closure prototype called
1639
1640(F) If a closure has attributes, the subroutine passed to an attribute
1641handler is the prototype that is cloned when a new closure is created.
1642This subroutine cannot be called.
1643
74d1b2e4
FC
1644=item \C no longer supported in regex; marked by S<<-- HERE> in m/%s/
1645
1646(F) The \C character class used to allow a match of single byte
1647within a multi-byte utf-8 character, but was removed in v5.24 as
1648it broke encapsulation and its implementation was extremely buggy.
1649If you really need to process the individual bytes, you probably
1650want to convert your string to one where each underlying byte is
1651stored as a character, with utf8::encode().
1652
49704364
LW
1653=item Code missing after '/'
1654
6903afa2
FC
1655(F) You had a (sub-)template that ends with a '/'. There must be
1656another template code following the slash. See L<perlfunc/pack>.
49704364 1657
c0236afe
KW
1658=item Code point 0x%X is not Unicode, and not portable
1659
1660(S non_unicode) You had a code point that has never been in any
1661standard, so it is likely that languages other than Perl will NOT
1662understand it. At one time, it was legal in some standards to have code
1663points up to 0x7FFF_FFFF, but not higher, and this code point is higher.
1664
1665Acceptance of these code points is a Perl extension, and you should
1666expect that nothing other than Perl can handle them; Perl itself on
1667EBCDIC platforms before v5.24 does not handle them.
1668
1669Code points above 0xFFFF_FFFF require larger than a 32 bit word.
1670
1671Perl also makes no guarantees that the representation of these code
1672points won't change at some point in the future, say when machines
1673become available that have larger than a 64-bit word. At that time,
1674files written by an older Perl would require conversion before being
1675readable by a newer Perl.
1676
5a25739d
FC
1677=item Code point 0x%X is not Unicode, may not be portable
1678
2d88a86a 1679(S non_unicode) You had a code point above the Unicode maximum
1b64326b
FC
1680of U+10FFFF.
1681
c0236afe
KW
1682Perl allows strings to contain a superset of Unicode code points, but
1683these may not be accepted by other languages/systems. Further, even if
1684these languages/systems accept these large code points, they may have
1685chosen a different representation for them than the UTF-8-like one that
1686Perl has, which would mean files are not exchangeable between them and
1687Perl.
1688
1689On EBCDIC platforms, code points above 0x3FFF_FFFF have a different
1690representation in Perl v5.24 than before, so any file containing these
1691that was written before that version will require conversion before
1692being readable by a later Perl.
0876b9a0 1693
6df41af2
GS
1694=item %s: Command not found
1695
a892b81a 1696(A) You've accidentally run your script through B<csh> or another shell
66a1f5ec
FC
1697instead of Perl. Check the #! line, or manually feed your script into
1698Perl yourself. The #! line at the top of your file could look like
8f721816
MM
1699
1700 #!/usr/bin/perl -w
6df41af2 1701
7a2e2cd6
PP
1702=item Compilation failed in require
1703
1704(F) Perl could not compile a file specified in a C<require> statement.
be771a83
GS
1705Perl uses this generic message when none of the errors that it
1706encountered were severe enough to halt compilation immediately.
7a2e2cd6 1707
c3464db5
DD
1708=item Complex regular subexpression recursion limit (%d) exceeded
1709
be771a83
GS
1710(W regexp) The regular expression engine uses recursion in complex
1711situations where back-tracking is required. Recursion depth is limited
1712to 32766, or perhaps less in architectures where the stack cannot grow
1713arbitrarily. ("Simple" and "medium" situations are handled without
1714recursion and are not subject to a limit.) Try shortening the string
1715under examination; looping in Perl code (e.g. with C<while>) rather than
1716in the regular expression engine; or rewriting the regular expression so
c2e66d9e 1717that it is simpler or backtracks less. (See L<perlfaq2> for information
be771a83 1718on I<Mastering Regular Expressions>.)
c3464db5 1719
69282e91 1720=item connect() on closed socket %s
a0d0e21e 1721
be771a83
GS
1722(W closed) You tried to do a connect on a closed socket. Did you forget
1723to check the return value of your socket() call? See
1724L<perlfunc/connect>.
a0d0e21e 1725
e21e7c6a
FC
1726=item Constant(%s): Call to &{$^H{%s}} did not return a defined value
1727
1728(F) The subroutine registered to handle constant overloading
1729(see L<overload>) or a custom charnames handler (see
1730L<charnames/CUSTOM TRANSLATORS>) returned an undefined value.
1731
1732=item Constant(%s): $^H{%s} is not defined
1733
1734(F) The parser found inconsistencies while attempting to define an
1735overloaded constant. Perhaps you forgot to load the corresponding
f738a371 1736L<overload> pragma?
e21e7c6a 1737
779c5bc9
GS
1738=item Constant is not %s reference
1739
1740(F) A constant value (perhaps declared using the C<use constant> pragma)
be771a83 1741is being dereferenced, but it amounts to the wrong type of reference.
6903afa2 1742The message indicates the type of reference that was expected. This
be771a83 1743usually indicates a syntax error in dereferencing the constant value.
779c5bc9
GS
1744See L<perlsub/"Constant Functions"> and L<constant>.
1745
0ac016fc
FC
1746=item Constants from lexical variables potentially modified elsewhere are
1747deprecated
1748
1749(D deprecated) You wrote something like
1750
1751 my $var;
1752 $sub = sub () { $var };
1753
1754but $var is referenced elsewhere and could be modified after the C<sub>
1755expression is evaluated. Either it is explicitly modified elsewhere
1756(C<$var = 3>) or it is passed to a subroutine or to an operator like
1757C<printf> or C<map>, which may or may not modify the variable.
1758
1759Traditionally, Perl has captured the value of the variable at that
1760point and turned the subroutine into a constant eligible for inlining.
1761In those cases where the variable can be modified elsewhere, this
1762breaks the behavior of closures, in which the subroutine captures
1763the variable itself, rather than its value, so future changes to the
1764variable are reflected in the subroutine's return value.
1765
1766This usage is deprecated, because the behavior is likely to change
1767in a future version of Perl.
1768
1769If you intended for the subroutine to be eligible for inlining, then
1770make sure the variable is not referenced elsewhere, possibly by
1771copying it:
1772
1773 my $var2 = $var;
1774 $sub = sub () { $var2 };
1775
1776If you do want this subroutine to be a closure that reflects future
1777changes to the variable that it closes over, add an explicit C<return>:
1778
1779 my $var;
1780 $sub = sub () { return $var };
1781
4cee8e80
CS
1782=item Constant subroutine %s redefined
1783
aeb94125
FC
1784(W redefine)(S) You redefined a subroutine which had previously
1785been eligible for inlining. See L<perlsub/"Constant Functions">
1786for commentary and workarounds.
4cee8e80 1787
9607fc9c
PP
1788=item Constant subroutine %s undefined
1789
be771a83
GS
1790(W misc) You undefined a subroutine which had previously been eligible
1791for inlining. See L<perlsub/"Constant Functions"> for commentary and
1792workarounds.
9607fc9c 1793
5a25739d
FC
1794=item Constant(%s) unknown
1795
1796(F) The parser found inconsistencies either while attempting
1797to define an overloaded constant, or when trying to find the
1798character name specified in the C<\N{...}> escape. Perhaps you
3ee1a09c 1799forgot to load the corresponding L<overload> pragma?
5a25739d 1800
4a873d7a
FC
1801=item :const is experimental
1802
1803(S experimental::const_attr) The "const" attribute is experimental.
1804If you want to use the feature, disable the warning with C<no warnings
1805'experimental::const_attr'>, but know that in doing so you are taking
1806the risk that your code may break in a future Perl version.
1807
b77472f9
FC
1808=item :const is not permitted on named subroutines
1809
1810(F) The "const" attribute causes an anonymous subroutine to be run and
465068b9 1811its value captured at the time that it is cloned. Named subroutines are
b77472f9
FC
1812not cloned like this, so the attribute does not make sense on them.
1813
e7ea3e70
IZ
1814=item Copy method did not return a reference
1815
6903afa2 1816(F) The method which overloads "=" is buggy. See
13a2d996 1817L<overload/Copy Constructor>.
e7ea3e70 1818
4aaa4757
FC
1819=item &CORE::%s cannot be called directly
1820
1821(F) You tried to call a subroutine in the C<CORE::> namespace
8d605c0d 1822with C<&foo> syntax or through a reference. Some subroutines
4aaa4757
FC
1823in this package cannot yet be called that way, but must be
1824called as barewords. Something like this will work:
1825
1826 BEGIN { *shove = \&CORE::push; }
1827 shove @array, 1,2,3; # pushes on to @array
1828
6798c92b
GS
1829=item CORE::%s is not a keyword
1830
1831(F) The CORE:: namespace is reserved for Perl keywords.
1832
675fa9ff
FC
1833=item Corrupted regexp opcode %d > %d
1834
1835(P) This is either an error in Perl, or, if you're using
1836one, your L<custom regular expression engine|perlreapi>. If not the
1837latter, report the problem through the L<perlbug> utility.
1838
a0d0e21e
LW
1839=item corrupted regexp pointers
1840
1841(P) The regular expression engine got confused by what the regular
1842expression compiler gave it.
1843
1844=item corrupted regexp program
1845
be771a83
GS
1846(P) The regular expression engine got passed a regexp program without a
1847valid magic number.
a0d0e21e 1848
de42a5a9 1849=item Corrupt malloc ptr 0x%x at 0x%x
6df41af2
GS
1850
1851(P) The malloc package that comes with Perl had an internal failure.
1852
49704364
LW
1853=item Count after length/code in unpack
1854
1855(F) You had an unpack template indicating a counted-length string, but
1856you have also specified an explicit size for the string. See
1857L<perlfunc/pack>.
1858
f2cccb4c
KW
1859=for comment
1860The following are used in lib/diagnostics.t for testing two =items that
1861share the same description. Changes here need to be propagated to there
1862
6651ba0b
FC
1863=item Deep recursion on anonymous subroutine
1864
a0d0e21e
LW
1865=item Deep recursion on subroutine "%s"
1866
be771a83
GS
1867(W recursion) This subroutine has called itself (directly or indirectly)
1868100 times more than it has returned. This probably indicates an
1869infinite recursion, unless you're writing strange benchmark programs, in
1870which case it indicates something else.
a0d0e21e 1871
aad1d01f
NC
1872This threshold can be changed from 100, by recompiling the F<perl> binary,
1873setting the C pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value.
1874
e0e4a6e3
FC
1875=item (?(DEFINE)....) does not allow branches in regex; marked by
1876S<<-- HERE> in m/%s/
bcb95744 1877
6903afa2 1878(F) You used something like C<(?(DEFINE)...|..)> which is illegal. The
bcb95744
FC
1879most likely cause of this error is that you left out a parenthesis inside
1880of the C<....> part.
1881
6e8a73f2 1882The S<<-- HERE> shows whereabouts in the regular expression the problem was
bcb95744
FC
1883discovered.
1884
62658f4d
PM
1885=item %s defines neither package nor VERSION--version check failed
1886
1887(F) You said something like "use Module 42" but in the Module file
1888there are neither package declarations nor a C<$VERSION>.
1889
36447869
FC
1890=item delete argument is index/value array slice, use array slice
1891
1892(F) You used index/value array slice syntax (C<%array[...]>) as
1893the argument to C<delete>. You probably meant C<@array[...]> with
1894an @ symbol instead.
1895
1896=item delete argument is key/value hash slice, use hash slice
1897
1898(F) You used key/value hash slice syntax (C<%hash{...}>) as the argument to
1899C<delete>. You probably meant C<@hash{...}> with an @ symbol instead.
1900
0ffcbc25
FC
1901=item delete argument is not a HASH or ARRAY element or slice
1902
4a0af295 1903(F) The argument to C<delete> must be either a hash or array element,
0ffcbc25
FC
1904such as:
1905
1906 $foo{$bar}
1907 $ref->{"susie"}[12]
1908
1909or a hash or array slice, such as:
1910
1911 @foo[$bar, $baz, $xyzzy]
1912 @{$ref->[12]}{"susie", "queue"}
1913
fc36a67e
PP
1914=item Delimiter for here document is too long
1915
be771a83
GS
1916(F) In a here document construct like C<<<FOO>, the label C<FOO> is too
1917long for Perl to handle. You have to be seriously twisted to write code
1918that triggers this error.
fc36a67e 1919
6d3b25aa
RGS
1920=item Deprecated use of my() in false conditional
1921
fa816bf3
FC
1922(D deprecated) You used a declaration similar to C<my $x if 0>. There
1923has been a long-standing bug in Perl that causes a lexical variable
6d3b25aa 1924not to be cleared at scope exit when its declaration includes a false
6903afa2 1925conditional. Some people have exploited this bug to achieve a kind of
fa816bf3 1926static variable. Since we intend to fix this bug, we don't want people
6903afa2 1927relying on this behavior. You can achieve a similar static effect by
6d3b25aa 1928declaring the variable in a separate block outside the function, eg
36fb85f3 1929
6d3b25aa
RGS
1930 sub f { my $x if 0; return $x++ }
1931
1932becomes
1933
1934 { my $x; sub f { return $x++ } }
1935
ea9d9ebc 1936Beginning with perl 5.10.0, you can also use C<state> variables to have
fa816bf3 1937lexicals that are initialized only once (see L<feature>):
36fb85f3
RGS
1938
1939 sub f { state $x; return $x++ }
1940
500ab966
RGS
1941=item DESTROY created new reference to dead object '%s'
1942
1943(F) A DESTROY() method created a new reference to the object which is
6903afa2
FC
1944just being DESTROYed. Perl is confused, and prefers to abort rather
1945than to create a dangling reference.
500ab966 1946
3cdd684c
TP
1947=item Did not produce a valid header
1948
1949See Server error.
1950
6df41af2
GS
1951=item %s did not return a true value
1952
1953(F) A required (or used) file must return a true value to indicate that
1954it compiled correctly and ran its initialization code correctly. It's
1955traditional to end such a file with a "1;", though any true value would
1956do. See L<perlfunc/require>.
1957
cc507455 1958=item (Did you mean &%s instead?)
4633a7c4 1959
413ff9f6
FC
1960(W misc) You probably referred to an imported subroutine &FOO as $FOO or
1961some such.
4633a7c4 1962
cc507455 1963=item (Did you mean "local" instead of "our"?)
33633739 1964
be771a83
GS
1965(W misc) Remember that "our" does not localize the declared global
1966variable. You have declared it again in the same lexical scope, which
1967seems superfluous.
33633739 1968
cc507455 1969=item (Did you mean $ or @ instead of %?)
a0d0e21e 1970
be771a83
GS
1971(W) You probably said %hash{$key} when you meant $hash{$key} or
1972@hash{@keys}. On the other hand, maybe you just meant %hash and got
1973carried away.
748a9306 1974
7e1af8bc 1975=item Died
5f05dabc
PP
1976
1977(F) You passed die() an empty string (the equivalent of C<die "">) or
075b00aa 1978you called it with no args and C<$@> was empty.
5f05dabc 1979
3cdd684c
TP
1980=item Document contains no data
1981
1982See Server error.
1983
62658f4d
PM
1984=item %s does not define %s::VERSION--version check failed
1985
1986(F) You said something like "use Module 42" but the Module did not
943fc58e 1987define a C<$VERSION>.
62658f4d 1988
49704364
LW
1989=item '/' does not take a repeat count
1990
1991(F) You cannot put a repeat count of any kind right after the '/' code.
1992See L<perlfunc/pack>.
1993
95cb0d72
FC
1994=item Don't know how to get file name
1995
1996(P) C<PerlIO_getname>, a perl internal I/O function specific to VMS, was
1997somehow called on another platform. This should not happen.
1998
4021c788 1999=item Don't know how to handle magic of type \%o
a0d0e21e
LW
2000
2001(P) The internal handling of magical variables has been cursed.
2002
2003=item do_study: out of memory
2004
2005(P) This should have been caught by safemalloc() instead.
2006
6df41af2
GS
2007=item (Do you need to predeclare %s?)
2008
56da5a46
RGS
2009(S syntax) This is an educated guess made in conjunction with the message
2010"%s found where operator expected". It often means a subroutine or module
6df41af2
GS
2011name is being referenced that hasn't been declared yet. This may be
2012because of ordering problems in your file, or because of a missing
be771a83
GS
2013"sub", "package", "require", or "use" statement. If you're referencing
2014something that isn't defined yet, you don't actually have to define the
2015subroutine or package before the current location. You can use an empty
2016"sub foo;" or "package FOO;" to enter a "forward" declaration.
6df41af2 2017
ac206dc8
RGS
2018=item dump() better written as CORE::dump()
2019
2020(W misc) You used the obsolescent C<dump()> built-in function, without fully
2021qualifying it as C<CORE::dump()>. Maybe it's a typo. See L<perlfunc/dump>.
2022
84d78eb7
YO
2023=item dump is not supported
2024
2025(F) Your machine doesn't support dump/undump.
2026
a0d0e21e
LW
2027=item Duplicate free() ignored
2028
be771a83
GS
2029(S malloc) An internal routine called free() on something that had
2030already been freed.
a0d0e21e 2031
1109a392
MHM
2032=item Duplicate modifier '%c' after '%c' in %s
2033
35f0cd76
FC
2034(W unpack) You have applied the same modifier more than once after a
2035type in a pack template. See L<perlfunc/pack>.
1109a392 2036
4633a7c4
LW
2037=item elseif should be elsif
2038
fa816bf3
FC
2039(S syntax) There is no keyword "elseif" in Perl because Larry thinks
2040it's ugly. Your code will be interpreted as an attempt to call a method
2041named "elseif" for the class returned by the following block. This is
4633a7c4
LW
2042unlikely to be what you want.
2043
c30c479a
KW
2044=item Empty \%c in regex; marked by S<<-- HERE> in m/%s/
2045
e0e4a6e3 2046=item Empty \%c{} in regex; marked by S<<-- HERE> in m/%s/
ab13f0c7 2047
af6f566e 2048(F) C<\p> and C<\P> are used to introduce a named Unicode property, as
6903afa2 2049described in L<perlunicode> and L<perlre>. You used C<\p> or C<\P> in
af6f566e 2050a regular expression without specifying the property name.
ab13f0c7 2051
85ab1d1d 2052=item entering effective %s failed
5ff3f7a4 2053
85ab1d1d 2054(F) While under the C<use filetest> pragma, switching the real and
5ff3f7a4
GS
2055effective uids or gids failed.
2056
c038024b
RGS
2057=item %ENV is aliased to %s
2058
2059(F) You're running under taint mode, and the C<%ENV> variable has been
2060aliased to another hash, so it doesn't reflect anymore the state of the
6903afa2 2061program's environment. This is potentially insecure.
c038024b 2062
748a9306
LW
2063=item Error converting file specification %s
2064
5f05dabc 2065(F) An error peculiar to VMS. Because Perl may have to deal with file
748a9306 2066specifications in either VMS or Unix syntax, it converts them to a
be771a83
GS
2067single form when it must operate on them directly. Either you've passed
2068an invalid file specification to Perl, or you've found a case the
2069conversion routines don't handle. Drat.
748a9306 2070
ad19ef22 2071=item Eval-group in insecure regular expression
e4d48cc9 2072
be771a83
GS
2073(F) Perl detected tainted data when trying to compile a regular
2074expression that contains the C<(?{ ... })> zero-width assertion, which
2075is unsafe. See L<perlre/(?{ code })>, and L<perlsec>.
e4d48cc9 2076
ad19ef22 2077=item Eval-group not allowed at runtime, use re 'eval' in regex m/%s/
e4d48cc9 2078
be771a83
GS
2079(F) Perl tried to compile a regular expression containing the
2080C<(?{ ... })> zero-width assertion at run time, as it would when the
f11307f5
FC
2081pattern contains interpolated values. Since that is a security risk,
2082it is not allowed. If you insist, you may still do this by using the
2083C<re 'eval'> pragma or by explicitly building the pattern from an
2084interpolated string at run time and using that in an eval(). See
2085L<perlre/(?{ code })>.
e4d48cc9 2086
ad19ef22 2087=item Eval-group not allowed, use re 'eval' in regex m/%s/
6df41af2 2088
be771a83
GS
2089(F) A regular expression contained the C<(?{ ... })> zero-width
2090assertion, but that construct is only allowed when the C<use re 'eval'>
2091pragma is in effect. See L<perlre/(?{ code })>.
6df41af2 2092
e0e4a6e3
FC
2093=item EVAL without pos change exceeded limit in regex; marked by
2094S<<-- HERE> in m/%s/
1a147d38
YO
2095
2096(F) You used a pattern that nested too many EVAL calls without consuming
6903afa2 2097any text. Restructure the pattern so that text is consumed.
1a147d38 2098
6e8a73f2 2099The S<<-- HERE> shows whereabouts in the regular expression the problem was
1a147d38
YO
2100discovered.
2101
fc36a67e
PP
2102=item Excessively long <> operator
2103
2104(F) The contents of a <> operator may not exceed the maximum size of a
2105Perl identifier. If you're just trying to glob a long list of
2106filenames, try using the glob() operator, or put the filenames into a
2107variable and glob that.
2108
ed9aa3b7
SG
2109=item exec? I'm not *that* kind of operating system
2110
af8bb25a 2111(F) The C<exec> function is not implemented on some systems, e.g., Symbian
6903afa2 2112OS. See L<perlport>.
ed9aa3b7 2113
fe13d51d 2114=item Execution of %s aborted due to compilation errors.
a0d0e21e
LW
2115
2116(F) The final summary message when a Perl compilation fails.
2117
0ffcbc25
FC
2118=item exists argument is not a HASH or ARRAY element or a subroutine
2119
4a0af295 2120(F) The argument to C<exists> must be a hash or array element or a
0ffcbc25
FC
2121subroutine with an ampersand, such as:
2122
2123 $foo{$bar}
2124 $ref->{"susie"}[12]
2125 &do_something
2126
2127=item exists argument is not a subroutine name
2128
ccfc2567
FC
2129(F) The argument to C<exists> for C<exists &sub> must be a subroutine name,
2130and not a subroutine call. C<exists &sub()> will generate this error.
0ffcbc25 2131
a0d0e21e
LW
2132=item Exiting eval via %s
2133
be771a83
GS
2134(W exiting) You are exiting an eval by unconventional means, such as a
2135goto, or a loop control statement.
e476b1b5
GS
2136
2137=item Exiting format via %s
2138
9a2ff54b 2139(W exiting) You are exiting a format by unconventional means, such as a
be771a83 2140goto, or a loop control statement.
a0d0e21e 2141
0a753a76
PP
2142=item Exiting pseudo-block via %s
2143
be771a83
GS
2144(W exiting) You are exiting a rather special block construct (like a
2145sort block or subroutine) by unconventional means, such as a goto, or a
2146loop control statement. See L<perlfunc/sort>.
0a753a76 2147
a0d0e21e
LW
2148=item Exiting subroutine via %s
2149
be771a83
GS
2150(W exiting) You are exiting a subroutine by unconventional means, such
2151as a goto, or a loop control statement.
a0d0e21e
LW
2152
2153=item Exiting substitution via %s
2154
be771a83
GS
2155(W exiting) You are exiting a substitution by unconventional means, such
2156as a return, a goto, or a loop control statement.
a0d0e21e 2157
e0e4a6e3 2158=item Expecting close bracket in regex; marked by S<<-- HERE> in m/%s/
c608e803 2159
675fa9ff 2160(F) You wrote something like
c608e803
KW
2161
2162 (?13
2163
2164to denote a capturing group of the form
2165L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>,
2166but omitted the C<")">.
2167
e0e4a6e3 2168=item Expecting '(?flags:(?[...' in regex; marked by S<<-- HERE> in m/%s/
27350048 2169
8b6fbf55
FC
2170(F) The C<(?[...])> extended character class regular expression construct
2171only allows character classes (including character class escapes like
2172C<\d>), operators, and parentheses. The one exception is C<(?flags:...)>
2173containing at least one flag and exactly one C<(?[...])> construct.
27350048
FC
2174This allows a regular expression containing just C<(?[...])> to be
2175interpolated. If you see this error message, then you probably
2176have some other C<(?...)> construct inside your character class. See
2177L<perlrecharclass/Extended Bracketed Character Classes>.
2178
baabe3fb 2179=item Experimental aliasing via reference not enabled
1f8155a2 2180
baabe3fb 2181(F) To do aliasing via references, you must first enable the feature:
1f8155a2 2182
baabe3fb
FC
2183 no warnings "experimental::refaliasing";
2184 use feature "refaliasing";
1f8155a2
FC
2185 \$x = \$y;
2186
74d1b2e4
FC
2187=item Experimental %s on scalar is now forbidden
2188
2189(F) An experimental feature added in Perl 5.14 allowed C<each>, C<keys>,
2190C<push>, C<pop>, C<shift>, C<splice>, C<unshift>, and C<values> to be called with a
2191scalar argument. This experiment is considered unsuccessful, and
2192has been removed. The C<postderef> feature may meet your needs better.
2193
30d9c59b
Z
2194=item Experimental subroutine signatures not enabled
2195
2196(F) To use subroutine signatures, you must first enable them:
2197
caa35032 2198 no warnings "experimental::signatures";
30d9c59b
Z
2199 use feature "signatures";
2200 sub foo ($left, $right) { ... }
2201
6da34ecb
FC
2202=item Experimental "%s" subs not enabled
2203
2204(F) To use lexical subs, you must first enable them:
2205
2206 no warnings 'experimental::lexical_subs';
2207 use feature 'lexical_subs';
2208 my sub foo { ... }
2209
7b8d334a
GS
2210=item Explicit blessing to '' (assuming package main)
2211
be771a83
GS
2212(W misc) You are blessing a reference to a zero length string. This has
2213the effect of blessing the reference into the package main. This is
2214usually not what you want. Consider providing a default target package,
2215e.g. bless($ref, $p || 'MyPackage');
7b8d334a 2216
6df41af2
GS
2217=item %s: Expression syntax
2218
be771a83
GS
2219(A) You've accidentally run your script through B<csh> instead of Perl.
2220Check the #! line, or manually feed your script into Perl yourself.
6df41af2
GS
2221
2222=item %s failed--call queue aborted
2223
3c10abe3
AG
2224(F) An untrapped exception was raised while executing a UNITCHECK,
2225CHECK, INIT, or END subroutine. Processing of the remainder of the
2226queue of such routines has been prematurely ended.
6df41af2 2227
502aca56
TC
2228=item Failed to close in-place edit file %s: %s
2229
2230(F) Closing an output file from in-place editing, as with the C<-i>
2231command-line switch, failed.
2232
e0e4a6e3 2233=item False [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
73b437c8 2234
98d31c73 2235(W regexp)(F) A character class range must start and end at a literal
7253e4e3 2236character, not another character class like C<\d> or C<[:alpha:]>. The "-"
3c6ca74a
FC
2237in your false range is interpreted as a literal "-". In a C<(?[...])>
2238construct, this is an error, rather than a warning. Consider quoting
e0e4a6e3 2239the "-", "\-". The S<<-- HERE> shows whereabouts in the regular expression
3c6ca74a 2240the problem was discovered. See L<perlre>.
73b437c8 2241
1b1ee2ef 2242=item Fatal VMS error (status=%d) at %s, line %d
a0d0e21e 2243
be771a83
GS
2244(P) An error peculiar to VMS. Something untoward happened in a VMS
2245system service or RTL routine; Perl's exit status should provide more
2246details. The filename in "at %s" and the line number in "line %d" tell
2247you which section of the Perl source code is distressed.
a0d0e21e
LW
2248
2249=item fcntl is not implemented
2250
2251(F) Your machine apparently doesn't implement fcntl(). What is this, a
2252PDP-11 or something?
2253
22846ab4
AB
2254=item FETCHSIZE returned a negative value
2255
2256(F) A tied array claimed to have a negative number of elements, which
2257is not possible.
2258
f337b084
TH
2259=item Field too wide in 'u' format in pack
2260
d8b5cc61 2261(W pack) Each line in an uuencoded string starts with a length indicator
6903afa2
FC
2262which can't encode values above 63. So there is no point in asking for
2263a line length bigger than that. Perl will behave as if you specified
5c96f6f7 2264C<u63> as the format.
f337b084 2265
af8c498a 2266=item Filehandle %s opened only for input
a0d0e21e 2267
6c8d78fb
HS
2268(W io) You tried to write on a read-only filehandle. If you intended
2269it to be a read-write filehandle, you needed to open it with "+<" or
2270"+>" or "+>>" instead of with "<" or nothing. If you intended only to
2271write the file, use ">" or ">>". See L<perlfunc/open>.
a0d0e21e 2272
af8c498a 2273=item Filehandle %s opened only for output
a0d0e21e 2274
6c8d78fb
HS
2275(W io) You tried to read from a filehandle opened only for writing, If
2276you intended it to be a read/write filehandle, you needed to open it
89a1bda8
FC
2277with "+<" or "+>" or "+>>" instead of with ">". If you intended only to
2278read from the file, use "<". See L<perlfunc/open>. Another possibility
2279is that you attempted to open filedescriptor 0 (also known as STDIN) for
2280output (maybe you closed STDIN earlier?).
97828cef
RGS
2281
2282=item Filehandle %s reopened as %s only for input
2283
2284(W io) You opened for reading a filehandle that got the same filehandle id
6903afa2 2285as STDOUT or STDERR. This occurred because you closed STDOUT or STDERR
97828cef
RGS
2286previously.
2287
2288=item Filehandle STDIN reopened as %s only for output
2289
2290(W io) You opened for writing a filehandle that got the same filehandle id
fa816bf3 2291as STDIN. This occurred because you closed STDIN previously.
a0d0e21e
LW
2292
2293=item Final $ should be \$ or $name
2294
2295(F) You must now decide whether the final $ in a string was meant to be
be771a83
GS
2296a literal dollar sign, or was meant to introduce a variable name that
2297happens to be missing. So you have to put either the backslash or the
2298name.
a0d0e21e 2299
56e90b21
GS
2300=item flock() on closed filehandle %s
2301
be771a83 2302(W closed) The filehandle you're attempting to flock() got itself closed
c289d2f7 2303some time before now. Check your control flow. flock() operates on
be771a83
GS
2304filehandles. Are you attempting to call flock() on a dirhandle by the
2305same name?
56e90b21 2306
6df41af2
GS
2307=item Format not terminated
2308
2309(F) A format must be terminated by a line with a solitary dot. Perl got
2310to the end of your file without finding such a line.
2311
a0d0e21e
LW
2312=item Format %s redefined
2313
e476b1b5 2314(W redefine) You redefined a format. To suppress this warning, say
a0d0e21e
LW
2315
2316 {
271595cc 2317 no warnings 'redefine';
a0d0e21e
LW
2318 eval "format NAME =...";
2319 }
2320
a0d0e21e
LW
2321=item Found = in conditional, should be ==
2322
e476b1b5 2323(W syntax) You said
a0d0e21e
LW
2324
2325 if ($foo = 123)
2326
2327when you meant
2328
2329 if ($foo == 123)
2330
2331(or something like that).
2332
6df41af2
GS
2333=item %s found where operator expected
2334
56da5a46
RGS
2335(S syntax) The Perl lexer knows whether to expect a term or an operator.
2336If it sees what it knows to be a term when it was expecting to see an
be771a83
GS
2337operator, it gives you this warning. Usually it indicates that an
2338operator or delimiter was omitted, such as a semicolon.
6df41af2 2339
a0d0e21e
LW
2340=item gdbm store returned %d, errno %d, key "%s"
2341
2342(S) A warning from the GDBM_File extension that a store failed.
2343
2344=item gethostent not implemented
2345
2346(F) Your C library apparently doesn't implement gethostent(), probably
2347because if it did, it'd feel morally obligated to return every hostname
2348on the Internet.
2349
69282e91 2350=item get%sname() on closed socket %s
a0d0e21e 2351
be771a83
GS
2352(W closed) You tried to get a socket or peer socket name on a closed
2353socket. Did you forget to check the return value of your socket() call?
a0d0e21e 2354
748a9306
LW
2355=item getpwnam returned invalid UIC %#o for user "%s"
2356
2357(S) A warning peculiar to VMS. The call to C<sys$getuai> underlying the
2358C<getpwnam> operator returned an invalid UIC.
2359
6df41af2
GS
2360=item getsockopt() on closed socket %s
2361
be771a83
GS
2362(W closed) You tried to get a socket option on a closed socket. Did you
2363forget to check the return value of your socket() call? See
6df41af2
GS
2364L<perlfunc/getsockopt>.
2365
0f539b13
BF
2366=item given is experimental
2367
675fa9ff
FC
2368(S experimental::smartmatch) C<given> depends on smartmatch, which
2369is experimental, so its behavior may change or even be removed
2370in any future release of perl. See the explanation under
2371L<perlsyn/Experimental Details on given and when>.
0f539b13 2372
68567d27
FC
2373=item Global symbol "%s" requires explicit package name (did you forget to
2374declare "my %s"?)
6df41af2 2375
a4edf47d 2376(F) You've said "use strict" or "use strict vars", which indicates
30c282f6 2377that all variables must either be lexically scoped (using "my" or "state"),
a4edf47d
GS
2378declared beforehand using "our", or explicitly qualified to say
2379which package the global variable is in (using "::").
6df41af2 2380
e476b1b5
GS
2381=item glob failed (%s)
2382
5ead438e 2383(S glob) Something went wrong with the external program(s) used
73c4e9dc
FC
2384for C<glob> and C<< <*.c> >>. Usually, this means that you supplied a C<glob>
2385pattern that caused the external program to fail and exit with a
be771a83 2386nonzero status. If the message indicates that the abnormal exit
73c4e9dc
FC
2387resulted in a coredump, this may also mean that your csh (C shell)
2388is broken. If so, you should change all of the csh-related variables
2389in config.sh: If you have tcsh, make the variables refer to it as
2390if it were csh (e.g. C<full_csh='/usr/bin/tcsh'>); otherwise, make them
2391all empty (except that C<d_csh> should be C<'undef'>) so that Perl will
be771a83 2392think csh is missing. In either case, after editing config.sh, run
75b44862 2393C<./Configure -S> and rebuild Perl.
e476b1b5 2394
a0d0e21e
LW
2395=item Glob not terminated
2396
2397(F) The lexer saw a left angle bracket in a place where it was expecting
be771a83
GS
2398a term, so it's looking for the corresponding right angle bracket, and
2399not finding it. Chances are you left some needed parentheses out
2400earlier in the line, and you really meant a "less than".
a0d0e21e 2401
b35b96b6
JH
2402=item gmtime(%f) failed
2403
2404(W overflow) You called C<gmtime> with a number that it could not handle:
2405too large, too small, or NaN. The returned value is C<undef>.
2406
bcd05b94 2407=item gmtime(%f) too large
8b56d6ff 2408
e9200be3 2409(W overflow) You called C<gmtime> with a number that was larger than
fc003d4b 2410it can reliably handle and C<gmtime> probably returned the wrong
6903afa2 2411date. This warning is also triggered with NaN (the special
fc003d4b
MS
2412not-a-number value).
2413
bcd05b94 2414=item gmtime(%f) too small
fc003d4b 2415
e9200be3 2416(W overflow) You called C<gmtime> with a number that was smaller than
e7a1a147 2417it can reliably handle and C<gmtime> probably returned the wrong date.
8b56d6ff 2418
6df41af2 2419=item Got an error from DosAllocMem
a0d0e21e 2420
6df41af2
GS
2421(P) An error peculiar to OS/2. Most probably you're using an obsolete
2422version of Perl, and this should not happen anyway.
a0d0e21e
LW
2423
2424=item goto must have label
2425
2426(F) Unlike with "next" or "last", you're not allowed to goto an
2427unspecified destination. See L<perlfunc/goto>.
2428
6651ba0b
FC
2429=item Goto undefined subroutine%s
2430
2431(F) You tried to call a subroutine with C<goto &sub> syntax, but
2432the indicated subroutine hasn't been defined, or if it was, it
2433has since been undefined.
2434
6fbc9859 2435=item Group name must start with a non-digit word character in regex; marked by
e0e4a6e3 2436S<<-- HERE> in m/%s/
1f4f6bf1
YO
2437
2438(F) Group names must follow the rules for perl identifiers, meaning
f26c79ba
FC
2439they must start with a non-digit word character. A common cause of
2440this error is using (?&0) instead of (?0). See L<perlre>.
1f4f6bf1 2441
5a25739d
FC
2442=item ()-group starts with a count
2443
2444(F) A ()-group started with a count. A count is supposed to follow
2445something: a template character or a ()-group. See L<perlfunc/pack>.
2446
fe13d51d 2447=item %s had compilation errors.
6df41af2
GS
2448
2449(F) The final summary message when a C<perl -c> fails.
2450
a0d0e21e
LW
2451=item Had to create %s unexpectedly
2452
be771a83
GS
2453(S internal) A routine asked for a symbol from a symbol table that ought
2454to have existed already, but for some reason it didn't, and had to be
2455created on an emergency basis to prevent a core dump.
a0d0e21e 2456
6df41af2
GS
2457=item %s has too many errors
2458
2459(F) The parser has given up trying to parse the program after 10 errors.
2460Further error messages would likely be uninformative.
2461
cc4d09e1
KW
2462=item Having more than one /%c regexp modifier is deprecated
2463
2464(D deprecated, regexp) You used the indicated regular expression pattern
2465modifier at least twice in a string of modifiers. It is deprecated to
2466do this with this particular modifier, to allow future extensions to the
2467Perl language.
2468
61e61fbc
JH
2469=item Hexadecimal float: exponent overflow
2470
d8f2b442 2471(W overflow) The hexadecimal floating point has a larger exponent
61e61fbc
JH
2472than the floating point supports.
2473
2474=item Hexadecimal float: exponent underflow
2475
d8f2b442 2476(W overflow) The hexadecimal floating point has a smaller exponent
61e61fbc
JH
2477than the floating point supports.
2478
5488d373 2479=item Hexadecimal float: internal error (%s)
cf4f6003
JH
2480
2481(F) Something went horribly bad in hexadecimal float handling.
2482
61e61fbc
JH
2483=item Hexadecimal float: mantissa overflow
2484
2485(W overflow) The hexadecimal floating point literal had more bits in
2486the mantissa (the part between the 0x and the exponent, also known as
2487the fraction or the significand) than the floating point supports.
2488
40bca5ae
JH
2489=item Hexadecimal float: precision loss
2490
2491(W overflow) The hexadecimal floating point had internally more
2492digits than could be output. This can be caused by unsupported
2493long double formats, or by 64-bit integers not being available
2494(needed to retrieve the digits under some configurations).
2495
2496=item Hexadecimal float: unsupported long double format
2497
2498(F) You have configured Perl to use long doubles but
d8f2b442 2499the internals of the long double format are unknown;
40bca5ae
JH
2500therefore the hexadecimal float output is impossible.
2501
252aa082
JH
2502=item Hexadecimal number > 0xffffffff non-portable
2503
e476b1b5 2504(W portable) The hexadecimal number you specified is larger than 2**32-1
9e24b6e2
JH
2505(4294967295) and therefore non-portable between systems. See
2506L<perlport> for more on portability concerns.
252aa082 2507
8903cb82
PP
2508=item Identifier too long
2509
2510(F) Perl limits identifiers (names for variables, functions, etc.) to
fc36a67e 2511about 250 characters for simple names, and somewhat more for compound
be771a83
GS
2512names (like C<$A::B>). You've exceeded Perl's limits. Future versions
2513of Perl are likely to eliminate these arbitrary limitations.
8903cb82 2514
e0e4a6e3
FC
2515=item Ignoring zero length \N{} in character class in regex; marked by
2516S<<-- HERE> in m/%s/
fc8cd66c 2517
f3ba6905 2518(W regexp) Named Unicode character escapes (C<\N{...}>) may return a
0f44b2a5
FC
2519zero-length sequence. When such an escape is used in a character
2520class its behavior is not well defined. Check that the correct
2521escape has been used, and the correct charname handler is in scope.
fc8cd66c 2522
6df41af2 2523=item Illegal binary digit %s
f675dbe5 2524
6df41af2 2525(F) You used a digit other than 0 or 1 in a binary number.
f675dbe5 2526
6df41af2 2527=item Illegal binary digit %s ignored
a0d0e21e 2528
be771a83
GS
2529(W digit) You may have tried to use a digit other than 0 or 1 in a
2530binary number. Interpretation of the binary number stopped before the
2531offending digit.
a0d0e21e 2532
6597eb22
FC
2533=item Illegal character after '_' in prototype for %s : %s
2534
e4d150f1
FC
2535(W illegalproto) An illegal character was found in a prototype
2536declaration. The '_' in a prototype must be followed by a ';',
2537indicating the rest of the parameters are optional, or one of '@'
2538or '%', since those two will accept 0 or more final parameters.
6597eb22 2539
78d0fecf 2540=item Illegal character \%o (carriage return)
4fdae800 2541
d5898338 2542(F) Perl normally treats carriage returns in the program text as it
be771a83
GS
2543would any other whitespace, which means you should never see this error
2544when Perl was built using standard options. For some reason, your
2545version of Perl appears to have been built without this support. Talk
2546to your Perl administrator.
4fdae800 2547
d37a9538
ST
2548=item Illegal character in prototype for %s : %s
2549
197afce1 2550(W illegalproto) An illegal character was found in a prototype declaration.
2e9cc7ef 2551Legal characters in prototypes are $, @, %, *, ;, [, ], &, \, and +.
30d9c59b
Z
2552Perhaps you were trying to write a subroutine signature but didn't enable
2553that feature first (C<use feature 'signatures'>), so your signature was
2554instead interpreted as a bad prototype.
d37a9538 2555
904d85c5
RGS
2556=item Illegal declaration of anonymous subroutine
2557
2558(F) When using the C<sub> keyword to construct an anonymous subroutine,
6903afa2 2559you must always specify a block of code. See L<perlsub>.
904d85c5 2560
8e742a20
MHM
2561=item Illegal declaration of subroutine %s
2562
6903afa2 2563(F) A subroutine was not declared correctly. See L<perlsub>.
8e742a20 2564
a0d0e21e
LW
2565=item Illegal division by zero
2566
be771a83
GS
2567(F) You tried to divide a number by 0. Either something was wrong in
2568your logic, or you need to put a conditional in to guard against
2569meaningless input.
a0d0e21e 2570
6df41af2
GS
2571=item Illegal hexadecimal digit %s ignored
2572
be771a83
GS
2573(W digit) You may have tried to use a character other than 0 - 9 or
2574A - F, a - f in a hexadecimal number. Interpretation of the hexadecimal
2575number stopped before the illegal character.
6df41af2 2576
a0d0e21e
LW
2577=item Illegal modulus zero
2578
be771a83
GS
2579(F) You tried to divide a number by 0 to get the remainder. Most
2580numbers don't take to this kindly.
a0d0e21e 2581
6df41af2 2582=item Illegal number of bits in vec
399388f4 2583
6df41af2
GS
2584(F) The number of bits in vec() (the third argument) must be a power of
2585two from 1 to 32 (or 64, if your platform supports that).
399388f4
GS
2586
2587=item Illegal octal digit %s
a0d0e21e 2588
d1be9408 2589(F) You used an 8 or 9 in an octal number.
a0d0e21e 2590
399388f4 2591=item Illegal octal digit %s ignored
748a9306 2592
d1be9408 2593(W digit) You may have tried to use an 8 or 9 in an octal number.
75b44862 2594Interpretation of the octal number stopped before the 8 or 9.
748a9306 2595
e0e4a6e3 2596=item Illegal pattern in regex; marked by S<<-- HERE> in m/%s/
c608e803 2597
675fa9ff 2598(F) You wrote something like
c608e803
KW
2599
2600 (?+foo)
2601
2602The C<"+"> is valid only when followed by digits, indicating a
2603capturing group. See
2604L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>.
2605
375ed12a
JH
2606=item Illegal suidscript
2607
2608(F) The script run under suidperl was somehow illegal.
2609
fe13d51d 2610=item Illegal switch in PERL5OPT: -%c
6ff81951 2611
6df41af2 2612(X) The PERL5OPT environment variable may only be used to set the
646ca9b2 2613following switches: B<-[CDIMUdmtw]>.
6ff81951 2614
4003ea29
KW
2615=item Illegal user-defined property name
2616
2617(F) You specified a Unicode-like property name in a regular expression
2618pattern (using C<\p{}> or C<\P{}>) that Perl knows isn't an official
2619Unicode property, and was likely meant to be a user-defined property
2620name, but it can't be one of those, as they must begin with either C<In>
2621or C<Is>. Check the spelling. See also
2622L</Can't find Unicode property definition "%s">.
2623
6df41af2 2624=item Ill-formed CRTL environ value "%s"
81e118e0 2625
75b44862 2626(W internal) A warning peculiar to VMS. Perl tried to read the CRTL's
be771a83
GS
2627internal environ array, and encountered an element without the C<=>
2628delimiter used to separate keys from values. The element is ignored.
09bef843 2629
6df41af2 2630=item Ill-formed message in prime_env_iter: |%s|
54310121 2631
be771a83
GS
2632(W internal) A warning peculiar to VMS. Perl tried to read a logical
2633name or CLI symbol definition when preparing to iterate over %ENV, and
2634didn't see the expected delimiter between key and value, so the line was
2635ignored.
54310121 2636
6df41af2 2637=item (in cleanup) %s
9607fc9c 2638
be771a83
GS
2639(W misc) This prefix usually indicates that a DESTROY() method raised
2640the indicated exception. Since destructors are usually called by the
2641system at arbitrary points during execution, and often a vast number of
2642times, the warning is issued only once for any number of failures that
2643would otherwise result in the same message being repeated.
6df41af2 2644
be771a83
GS
2645Failure of user callbacks dispatched using the C<G_KEEPERR> flag could
2646also result in this warning. See L<perlcall/G_KEEPERR>.
9607fc9c 2647
e0e4a6e3
FC
2648=item Incomplete expression within '(?[ ])' in regex; marked by S<<-- HERE>
2649in m/%s/
0d0b4b3b 2650
675fa9ff 2651(F) There was a syntax error within the C<(?[ ])>. This can happen if the
0d0b4b3b
KW
2652expression inside the construct was completely empty, or if there are
2653too many or few operands for the number of operators. Perl is not smart
2654enough to give you a more precise indication as to what is wrong.
2655
6fbc9859
MH
2656=item Inconsistent hierarchy during C3 merge of class '%s': merging failed on
2657parent '%s'
2c7d6b9c
RGS
2658
2659(F) The method resolution order (MRO) of the given class is not
2660C3-consistent, and you have enabled the C3 MRO for this class. See the C3
2661documentation in L<mro> for more information.
2662
6a2ed79a 2663=item Infinite recursion in regex
1a147d38
YO
2664
2665(F) You used a pattern that references itself without consuming any input
6903afa2 2666text. You should check the pattern to ensure that recursive patterns
1a147d38
YO
2667either consume text or fail.
2668
6dbe9451
NC
2669=item Initialization of state variables in list context currently forbidden
2670
6903afa2
FC
2671(F) Currently the implementation of "state" only permits the
2672initialization of scalar variables in scalar context. Re-write
2673C<state ($a) = 42> as C<state $a = 42> to change from list to scalar
2674context. Constructions such as C<state (@a) = foo()> will be
2675supported in a future perl release.
6dbe9451 2676
2186f873
FC
2677=item %%s[%s] in scalar context better written as $%s[%s]
2678
2679(W syntax) In scalar context, you've used an array index/value slice
2680(indicated by %) to select a single element of an array. Generally
2681it's better to ask for a scalar value (indicated by $). The difference
2682is that C<$foo[&bar]> always behaves like a scalar, both in the value it
2683returns and when evaluating its argument, while C<%foo[&bar]> provides
2684a list context to its subscript, which can do weird things if you're
2685expecting only one subscript. When called in list context, it also
2686returns the index (what C<&bar> returns) in addition to the value.
2687
2688=item %%s{%s} in scalar context better written as $%s{%s}
2689
2690(W syntax) In scalar context, you've used a hash key/value slice
2691(indicated by %) to select a single element of a hash. Generally it's
2692better to ask for a scalar value (indicated by $). The difference
2693is that C<$foo{&bar}> always behaves like a scalar, both in the value
2694it returns and when evaluating its argument, while C<@foo{&bar}> and
2695provides a list context to its subscript, which can do weird things
2696if you're expecting only one subscript. When called in list context,
2697it also returns the key in addition to the value.
2698
a0d0e21e
LW
2699=item Insecure dependency in %s
2700
8b1a09fc 2701(F) You tried to do something that the tainting mechanism didn't like.
be771a83
GS
2702The tainting mechanism is turned on when you're running setuid or
2703setgid, or when you specify B<-T> to turn it on explicitly. The
2704tainting mechanism labels all data that's derived directly or indirectly
2705from the user, who is considered to be unworthy of your trust. If any
2706such data is used in a "dangerous" operation, you get this error. See
2707L<perlsec> for more information.
a0d0e21e
LW
2708
2709=item Insecure directory in %s
2710
be771a83
GS
2711(F) You can't use system(), exec(), or a piped open in a setuid or
2712setgid script if C<$ENV{PATH}> contains a directory that is writable by
df98f984
RGS
2713the world. Also, the PATH must not contain any relative directory.
2714See L<perlsec>.
a0d0e21e 2715
62f468fc 2716=item Insecure $ENV{%s} while running %s
a0d0e21e
LW
2717
2718(F) You can't use system(), exec(), or a piped open in a setuid or
62f468fc 2719setgid script if any of C<$ENV{PATH}>, C<$ENV{IFS}>, C<$ENV{CDPATH}>,
332d5f78
SR
2720C<$ENV{ENV}>, C<$ENV{BASH_ENV}> or C<$ENV{TERM}> are derived from data
2721supplied (or potentially supplied) by the user. The script must set
2722the path to a known value, using trustworthy data. See L<perlsec>.
a0d0e21e 2723
0e9be77f
DM
2724=item Insecure user-defined property %s
2725
2726(F) Perl detected tainted data when trying to compile a regular
2727expression that contains a call to a user-defined character property
2728function, i.e. C<\p{IsFoo}> or C<\p{InFoo}>.
2729See L<perlunicode/User-Defined Character Properties> and L<perlsec>.
2730
b9ef414d
FC
2731=item Integer overflow in format string for %s
2732
2733(F) The indexes and widths specified in the format string of C<printf()>
2734or C<sprintf()> are too large. The numbers must not overflow the size of
2735integers for your architecture.
2736
a7ae9550
GS
2737=item Integer overflow in %s number
2738
35928bc5 2739(S overflow) The hexadecimal, octal or binary number you have specified
be771a83
GS
2740either as a literal or as an argument to hex() or oct() is too big for
2741your architecture, and has been converted to a floating point number.
2742On a 32-bit architecture the largest hexadecimal, octal or binary number
9e24b6e2
JH
2743representable without overflow is 0xFFFFFFFF, 037777777777, or
27440b11111111111111111111111111111111 respectively. Note that Perl
2745transparently promotes all numbers to a floating point representation
2746internally--subject to loss of precision errors in subsequent
2747operations.
bbce6d69 2748
fc89ca81
FC
2749=item Integer overflow in srand
2750
2751(S overflow) The number you have passed to srand is too big to fit
2752in your architecture's integer representation. The number has been
2753replaced with the largest integer supported (0xFFFFFFFF on 32-bit
2754architectures). This means you may be getting less randomness than
2755you expect, because different random seeds above the maximum will
2756return the same sequence of random numbers.
2757
46314c13
JP
2758=item Integer overflow in version
2759
18da5252
FC
2760=item Integer overflow in version %d
2761
784d71ed
FC
2762(W overflow) Some portion of a version initialization is too large for
2763the size of integers for your architecture. This is not a warning
f084e84f 2764because there is no rational reason for a version to try and use an
784d71ed
FC
2765element larger than typically 2**32. This is usually caused by trying
2766to use some odd mathematical operation as a version, like 100/9.
46314c13 2767
e0e4a6e3 2768=item Internal disaster in regex; marked by S<<-- HERE> in m/%s/
6df41af2
GS
2769
2770(P) Something went badly wrong in the regular expression parser.
e0e4a6e3 2771The S<<-- HERE> shows whereabouts in the regular expression the problem was
b45f050a
JF
2772discovered.
2773
748a9306
LW
2774=item Internal inconsistency in tracking vforks
2775
be771a83
GS
2776(S) A warning peculiar to VMS. Perl keeps track of the number of times
2777you've called C<fork> and C<exec>, to determine whether the current call
2778to C<exec> should affect the current script or a subprocess (see
2779L<perlvms/"exec LIST">). Somehow, this count has become scrambled, so
2780Perl is making a guess and treating this C<exec> as a request to
2781terminate the Perl script and execute the specified command.
748a9306 2782
870978ae
FC
2783=item internal %<num>p might conflict with future printf extensions
2784
2785(S internal) Perl's internal routine that handles C<printf> and C<sprintf>
2786formatting follows a slightly different set of rules when called from
2787C or XS code. Specifically, formats consisting of digits followed
2788by "p" (e.g., "%7p") are reserved for future use. If you see this
2789message, then an XS module tried to call that routine with one such
2790reserved format.
2791
e0e4a6e3 2792=item Internal urp in regex; marked by S<<-- HERE> in m/%s/
b45f050a 2793
fa816bf3 2794(P) Something went badly awry in the regular expression parser. The
e0e4a6e3 2795S<<-- HERE> shows whereabouts in the regular expression the problem was
7253e4e3 2796discovered.
a0d0e21e 2797
6df41af2
GS
2798=item %s (...) interpreted as function
2799
75b44862 2800(W syntax) You've run afoul of the rule that says that any list operator
be771a83 2801followed by parentheses turns into a function, with all the list
64977eb6 2802operators arguments found inside the parentheses. See
13a2d996 2803L<perlop/Terms and List Operators (Leftward)>.
6df41af2 2804
f51551f7
FC
2805=item In '(?...)', the '(' and '?' must be adjacent in regex;
2806marked by S<<-- HERE> in m/%s/
2807
2808(F) The two-character sequence C<"(?"> in this context in a regular
2809expression pattern should be an indivisible token, with nothing
2810intervening between the C<"("> and the C<"?">, but you separated them
2811with whitespace.
2812
09bef843
SB
2813=item Invalid %s attribute: %s
2814
a4a4c9e2 2815(F) The indicated attribute for a subroutine or variable was not recognized
09bef843
SB
2816by Perl or by a user-supplied handler. See L<attributes>.
2817
2818=item Invalid %s attributes: %s
2819
a4a4c9e2 2820(F) The indicated attributes for a subroutine or variable were not
be771a83 2821recognized by Perl or by a user-supplied handler. See L<attributes>.
09bef843 2822
e0e4a6e3
FC
2823=item Invalid character in charnames alias definition; marked by
2824S<<-- HERE> in '%s
225fb84f
KW
2825
2826(F) You tried to create a custom alias for a character name, with
2827the C<:alias> option to C<use charnames> and the specified character in
2828the indicated name isn't valid. See L<charnames/CUSTOM ALIASES>.
2829
c8028aa6
TC
2830=item Invalid \0 character in %s for %s: %s\0%s
2831
fa3234e3
FC
2832(W syscalls) Embedded \0 characters in pathnames or other system call
2833arguments produce a warning as of 5.20. The parts after the \0 were
2834formerly ignored by system calls.
c8028aa6 2835
e0e4a6e3 2836=item Invalid character in \N{...}; marked by S<<-- HERE> in \N{%s}
a690c7c4
FC
2837
2838(F) Only certain characters are valid for character names. The
2839indicated one isn't. See L<charnames/CUSTOM ALIASES>.
2840
c635e13b
PP
2841=item Invalid conversion in %s: "%s"
2842
be771a83
GS
2843(W printf) Perl does not understand the given format conversion. See
2844L<perlfunc/sprintf>.
c635e13b 2845
e0e4a6e3
FC
2846=item Invalid escape in the specified encoding in regex; marked by
2847S<<-- HERE> in m/%s/
9e08bc66 2848
98d31c73 2849(W regexp)(F) The numeric escape (for example C<\xHH>) of value < 256
9e08bc66
ST
2850didn't correspond to a single character through the conversion
2851from the encoding specified by the encoding pragma.
98d31c73
FC
2852The escape was replaced with REPLACEMENT CHARACTER (U+FFFD)
2853instead, except within S<C<(?[ ])>>, where it is a fatal error.
e0e4a6e3 2854The S<<-- HERE> shows whereabouts in the regular expression the
9e08bc66
ST
2855escape was discovered.
2856
8149aa9f
FC
2857=item Invalid hexadecimal number in \N{U+...}
2858
e0e4a6e3
FC
2859=item Invalid hexadecimal number in \N{U+...} in regex; marked by
2860S<<-- HERE> in m/%s/
aec0ef10 2861
8149aa9f 2862(F) The character constant represented by C<...> is not a valid hexadecimal
74f8e9e3
FC
2863number. Either it is empty, or you tried to use a character other than
28640 - 9 or A - F, a - f in a hexadecimal number.
8149aa9f 2865
6651ba0b
FC
2866=item Invalid module name %s with -%c option: contains single ':'
2867
2868(F) The module argument to perl's B<-m> and B<-M> command-line options
2869cannot contain single colons in the module name, but only in the
2870arguments after "=". In other words, B<-MFoo::Bar=:baz> is ok, but
2871B<-MFoo:Bar=baz> is not.
2872
2c7d6b9c
RGS
2873=item Invalid mro name: '%s'
2874
162a3e34
FC
2875(F) You tried to C<mro::set_mro("classname", "foo")> or C<use mro 'foo'>,
2876where C<foo> is not a valid method resolution order (MRO). Currently,
2877the only valid ones supported are C<dfs> and C<c3>, unless you have loaded
2878a module that is a MRO plugin. See L<mro> and L<perlmroapi>.
2c7d6b9c 2879
40e4140b
FC
2880=item Invalid negative number (%s) in chr
2881
2882(W utf8) You passed a negative number to C<chr>. Negative numbers are
abc0aa9d 2883not valid character numbers, so it returns the Unicode replacement
40e4140b
FC
2884character (U+FFFD).
2885
74d1b2e4
FC
2886=item Invalid number '%s' for -C option.
2887
2888(F) You supplied a number to the -C option that either has extra leading
2889zeroes or overflows perl's unsigned integer representation.
2890
6651ba0b
FC
2891=item invalid option -D%c, use -D'' to see choices
2892
8ff21bfe
FC
2893(S debugging) Perl was called with invalid debugger flags. Call perl
2894with the B<-D> option with no flags to see the list of acceptable values.
982c4ecb 2895See also L<perlrun/-Dletters>.
6651ba0b 2896
6e8a73f2 2897=item Invalid quantifier in {,} in regex; marked by S<<-- HERE> in m/%s/
35cd12d1
HS
2898
2899(F) The pattern looks like a {min,max} quantifier, but the min or max
2900could not be parsed as a valid number - either it has leading zeroes,
2901or it represents too big a number to cope with. The S<<-- HERE> shows
2902where in the regular expression the problem was discovered. See L<perlre>.
2903
e0e4a6e3 2904=item Invalid [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
6df41af2
GS
2905
2906(F) The range specified in a character class had a minimum character
7253e4e3
RK
2907greater than the maximum character. One possibility is that you forgot the
2908C<{}> from your ending C<\x{}> - C<\x> without the curly braces can go only
e0e4a6e3 2909up to C<ff>. The S<<-- HERE> shows whereabouts in the regular expression the
7253e4e3 2910problem was discovered. See L<perlre>.
6df41af2 2911
d1573ac7 2912=item Invalid range "%s" in transliteration operator
c2e66d9e
GS
2913
2914(F) The range specified in the tr/// or y/// operator had a minimum
2915character greater than the maximum character. See L<perlop>.
2916
09bef843
SB
2917=item Invalid separator character %s in attribute list
2918
0120eecf 2919(F) Something other than a colon or whitespace was seen between the
be771a83
GS
2920elements of an attribute list. If the previous attribute had a
2921parenthesised parameter list, perhaps that list was terminated too soon.
2922See L<attributes>.
09bef843 2923
b4581f09
JH
2924=item Invalid separator character %s in PerlIO layer specification %s
2925
2bfc5f71
FC
2926(W layer) When pushing layers onto the Perl I/O system, something other
2927than a colon or whitespace was seen between the elements of a layer list.
b4581f09
JH
2928If the previous attribute had a parenthesised parameter list, perhaps that
2929list was terminated too soon.
2930
2c86d456
DG
2931=item Invalid strict version format (%s)
2932
fa816bf3 2933(F) A version number did not meet the "strict" criteria for versions.
2c86d456
DG
2934A "strict" version number is a positive decimal number (integer or
2935decimal-fraction) without exponentiation or else a dotted-decimal
2936v-string with a leading 'v' character and at least three components.
a6485a24 2937The parenthesized text indicates which criteria were not met.
2c86d456
DG
2938See the L<version> module for more details on allowed version formats.
2939
49704364 2940=item Invalid type '%s' in %s
96e4d5b1 2941
49704364
LW
2942(F) The given character is not a valid pack or unpack type.
2943See L<perlfunc/pack>.
6728c851 2944
49704364 2945(W) The given character is not a valid pack or unpack type but used to be
75b44862 2946silently ignored.
96e4d5b1 2947
2c86d456
DG
2948=item Invalid version format (%s)
2949
fa816bf3 2950(F) A version number did not meet the "lax" criteria for versions.
2c86d456
DG
2951A "lax" version number is a positive decimal number (integer or
2952decimal-fraction) without exponentiation or else a dotted-decimal
fa816bf3
FC
2953v-string. If the v-string has fewer than three components, it
2954must have a leading 'v' character. Otherwise, the leading 'v' is
2955optional. Both decimal and dotted-decimal versions may have a
2956trailing "alpha" component separated by an underscore character
2957after a fractional or dotted-decimal component. The parenthesized
2958text indicates which criteria were not met. See the L<version> module
2959for more details on allowed version formats.
46314c13 2960
798ae1b7
DG
2961=item Invalid version object
2962
fa816bf3
FC
2963(F) The internal structure of the version object was invalid.
2964Perhaps the internals were modified directly in some way or
2965an arbitrary reference was blessed into the "version" class.
798ae1b7 2966
cd209d9d 2967=item In '(*VERB...)', the '(' and '*' must be adjacent in regex;
e0e4a6e3 2968marked by S<<-- HERE> in m/%s/
675fa9ff 2969
cd209d9d 2970(F) The two-character sequence C<"(*"> in
675fa9ff
FC
2971this context in a regular expression pattern should be an
2972indivisible token, with nothing intervening between the C<"(">
cd209d9d 2973and the C<"*">, but you separated them.
675fa9ff 2974
a0d0e21e
LW
2975=item ioctl is not implemented
2976
2977(F) Your machine apparently doesn't implement ioctl(), which is pretty
2978strange for a machine that supports C.
2979
c289d2f7
JH
2980=item ioctl() on unopened %s
2981
2982(W unopened) You tried ioctl() on a filehandle that was never opened.
34b6fd5e 2983Check your control flow and number of arguments.
c289d2f7 2984
fe13d51d 2985=item IO layers (like '%s') unavailable
363c40c4
SB
2986
2987(F) Your Perl has not been configured to have PerlIO, and therefore
34b6fd5e 2988you cannot use IO layers. To have PerlIO, Perl must be configured
363c40c4
SB
2989with 'useperlio'.
2990
80cbd5ad
JH
2991=item IO::Socket::atmark not implemented on this architecture
2992
2993(F) Your machine doesn't implement the sockatmark() functionality,
34b6fd5e 2994neither as a system call nor an ioctl call (SIOCATMARK).
80cbd5ad 2995
6e8a73f2 2996=item '%s' is an unknown bound type in regex; marked by S<<-- HERE> in m/%s/
64935bc6
KW
2997
2998(F) You used C<\b{...}> or C<\B{...}> and the C<...> is not known to
2999Perl. The current valid ones are given in
3000L<perlrebackslash/\b{}, \b, \B{}, \B>.
3001
74d1b2e4
FC
3002=item %s() is deprecated on :utf8 handles
3003
3004(W deprecated) The sysread(), recv(), syswrite() and send() operators are
3005deprecated on handles that have the C<:utf8> layer, either explicitly, or
3006implicitly, eg., with the C<:encoding(UTF-16LE)> layer.
3007
3008Both sysread() and recv() currently use only the C<:utf8> flag for the stream,
3009ignoring the actual layers. Since sysread() and recv() do no UTF-8
3010validation they can end up creating invalidly encoded scalars.
3011
3012Similarly, syswrite() and send() use only the C<:utf8> flag, otherwise ignoring
3013any layers. If the flag is set, both write the value UTF-8 encoded, even if
3014the layer is some different encoding, such as the example above.
3015
3016Ideally, all of these operators would completely ignore the C<:utf8> state,
3017working only with bytes, but this would result in silently breaking existing
3018code. To avoid this a future version of perl will throw an exception when
3019any of sysread(), recv(), syswrite() or send() are called on handle with the
3020C<:utf8> layer.
3021
6e8a73f2 3022=item "%s" is more clearly written simply as "%s" in regex; marked by S<<-- HERE> in m/%s/
acdfc3b6
KW
3023
3024(W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
3025
3026You specified a character that has the given plainer way of writing it,
3027and which is also portable to platforms running with different character
3028sets.
3029
4f650b80 3030=item $* is no longer supported
b4581f09 3031
4f650b80 3032(D deprecated, syntax) The special variable C<$*>, deprecated in older
ea9d9ebc 3033perls, has been removed as of 5.10.0 and is no longer supported. In
4f650b80
NC
3034previous versions of perl the use of C<$*> enabled or disabled multi-line
3035matching within a string.
4fd19576
B
3036
3037Instead of using C<$*> you should use the C</m> (and maybe C</s>) regexp
6903afa2
FC
3038modifiers. You can enable C</m> for a lexical scope (even a whole file)
3039with C<use re '/m'>. (In older versions: when C<$*> was set to a true value
570dedd4 3040then all regular expressions behaved as if they were written using C</m>.)
b4581f09 3041
8ae1fe26
RGS
3042=item $# is no longer supported
3043
a58ac25e 3044(D deprecated, syntax) The special variable C<$#>, deprecated in older
ea9d9ebc 3045perls, has been removed as of 5.10.0 and is no longer supported. You
a58ac25e 3046should use the printf/sprintf functions instead.
8ae1fe26 3047
ccf3535a 3048=item '%s' is not a code reference
6ad11d81 3049
6903afa2
FC
3050(W overload) The second (fourth, sixth, ...) argument of
3051overload::constant needs to be a code reference. Either
3052an anonymous subroutine, or a reference to a subroutine.
6ad11d81 3053
ccf3535a 3054=item '%s' is not an overloadable type
6ad11d81 3055
04a80ee0
RGS
3056(W overload) You tried to overload a constant type the overload package is
3057unaware of.
6ad11d81 3058
5a25739d
FC
3059=item -i used with no filenames on the command line, reading from STDIN
3060
3061(S inplace) The C<-i> option was passed on the command line, indicating
3062that the script is intended to edit files in place, but no files were
3063given. This is usually a mistake, since editing STDIN in place doesn't
3064make sense, and can be confusing because it can make perl look like
3065it is hanging when it is really just trying to read from STDIN. You
3066should either pass a filename to edit, or remove C<-i> from the command
3067line. See L<perlrun> for more details.
3068
aec0ef10 3069=item Junk on end of regexp in regex m/%s/
a0d0e21e
LW
3070
3071(P) The regular expression parser is confused.
3072
3073=item Label not found for "last %s"
3074
be771a83
GS
3075(F) You named a loop to break out of, but you're not currently in a loop
3076of that name, not even if you count where you were called from. See
3077L<perlfunc/last>.
a0d0e21e
LW
3078
3079=item Label not found for "next %s"
3080
3081(F) You named a loop to continue, but you're not currently in a loop of
3082that name, not even if you count where you were called from. See
3083L<perlfunc/last>.
3084
3085=item Label not found for "redo %s"
3086
3087(F) You named a loop to restart, but you're not currently in a loop of
3088that name, not even if you count where you were called from. See
3089L<perlfunc/last>.
3090
85ab1d1d 3091=item leaving effective %s failed
5ff3f7a4 3092
85ab1d1d 3093(F) While under the C<use filetest> pragma, switching the real and
5ff3f7a4
GS
3094effective uids or gids failed.
3095
49704364
LW
3096=item length/code after end of string in unpack
3097
d7f8936a 3098(F) While unpacking, the string buffer was already used up when an unpack
6903afa2
FC
3099length/code combination tried to obtain more data. This results in
3100an undefined value for the length. See L<perlfunc/pack>.
49704364 3101
25e26107 3102=item length() used on %s (did you mean "scalar(%s)"?)
e508c8a4 3103
0d46a4e7
FC
3104(W syntax) You used length() on either an array or a hash when you
3105probably wanted a count of the items.
e508c8a4
MH
3106
3107Array size can be obtained by doing:
3108
3109 scalar(@array);
3110
3111The number of items in a hash can be obtained by doing:
3112
3113 scalar(keys %hash);
3114
f0e67a1d
Z
3115=item Lexing code attempted to stuff non-Latin-1 character into Latin-1 input
3116
d4fe7078
RS
3117(F) An extension is attempting to insert text into the current parse
3118(using L<lex_stuff_pvn|perlapi/lex_stuff_pvn> or similar), but tried to insert a character that
3119couldn't be part of the current input. This is an inherent pitfall
3120of the stuffing mechanism, and one of the reasons to avoid it. Where
6903afa2 3121it is necessary to stuff, stuffing only plain ASCII is recommended.
f0e67a1d
Z
3122
3123=item Lexing code internal error (%s)
3124
3125(F) Lexing code supplied by an extension violated the lexer's API in a
3126detectable way.
3127
69282e91 3128=item listen() on closed socket %s
a0d0e21e 3129
be771a83
GS
3130(W closed) You tried to do a listen on a closed socket. Did you forget
3131to check the return value of your socket() call? See
3132L<perlfunc/listen>.
a0d0e21e 3133
6651ba0b
FC
3134=item List form of piped open not implemented
3135
3136(F) On some platforms, notably Windows, the three-or-more-arguments
3137form of C<open> does not support pipes, such as C<open($pipe, '|-', @args)>.
3138Use the two-argument C<open($pipe, '|prog arg1 arg2...')> form instead.
3139
dc6bb7ba
FC
3140=item %s: loadable library and perl binaries are mismatched (got handshake key %p, needed %p)
3141
3142(P) A dynamic loading library C<.so> or C<.dll> was being loaded into the
3143process that was built against a different build of perl than the
3144said library was compiled against. Reinstalling the XS module will
3145likely fix this error.
3146
8c6180a9
KW
3147=item Locale '%s' may not work well.%s
3148
780fcc9f 3149(W locale) You are using the named locale, which is a non-UTF-8 one, and
dae67c56
KW
3150which perl has determined is not fully compatible with what it can
3151handle. The second C<%s> gives a reason.
8c6180a9
KW
3152
3153By far the most common reason is that the locale has characters in it
3154that are represented by more than one byte. The only such locales that
3155Perl can handle are the UTF-8 locales. Most likely the specified locale
3156is a non-UTF-8 one for an East Asian language such as Chinese or
3157Japanese. If the locale is a superset of ASCII, the ASCII portion of it
780fcc9f 3158may work in Perl.
8c6180a9
KW
3159
3160Some essentially obsolete locales that aren't supersets of ASCII, mainly
3161those in ISO 646 or other 7-bit locales, such as ASMO 449, can also have
3162problems, depending on what portions of the ASCII character set get
3163changed by the locale and are also used by the program.
3164The warning message lists the determinable conflicting characters.
3165
780fcc9f
KW
3166Note that not all incompatibilities are found.
3167
3168If this happens to you, there's not much you can do except switch to use a
3169different locale or use L<Encode> to translate from the locale into
3170UTF-8; if that's impracticable, you have been warned that some things
3171may break.
3172
3173This message is output once each time a bad locale is switched into
3174within the scope of C<S<use locale>>, or on the first possibly-affected
3175operation if the C<S<use locale>> inherits a bad one. It is not raised
3176for any operations from the L<POSIX> module.
3177
a2162cd9
FC
3178=item localtime(%f) failed
3179
3180(W overflow) You called C<localtime> with a number that it could not handle:
3181too large, too small, or NaN. The returned value is C<undef>.
3182
3183=item localtime(%f) too large
3184
3185(W overflow) You called C<localtime> with a number that was larger
3186than it can reliably handle and C<localtime> probably returned the
3187wrong date. This warning is also triggered with NaN (the special
3188not-a-number value).
3189
3190=item localtime(%f) too small
3191
3192(W overflow) You called C<localtime> with a number that was smaller
3193than it can reliably handle and C<localtime> probably returned the
3194wrong date.
3195
58e23c8d 3196=item Lookbehind longer than %d not implemented in regex m/%s/
b45f050a
JF
3197
3198(F) There is currently a limit on the length of string which lookbehind can
6903afa2 3199handle. This restriction may be eased in a future release.
2e50fd82 3200
b88df990
NC
3201=item Lost precision when %s %f by 1
3202
e63e8a91
FC
3203(W imprecision) The value you attempted to increment or decrement by one
3204is too large for the underlying floating point representation to store
3205accurately, hence the target of C<++> or C<--> is unchanged. Perl issues this
3206warning because it has already switched from integers to floating point
3207when values are too large for integers, and now even floating point is
3208insufficient. You may wish to switch to using L<Math::BigInt> explicitly.
b88df990 3209
93fad930 3210=item lstat() on filehandle%s
2f7da168
RK
3211
3212(W io) You tried to do an lstat on a filehandle. What did you mean
3213by that? lstat() makes sense only on filenames. (Perl did a fstat()
3214instead on the filehandle.)
3215
345d70e3 3216=item lvalue attribute %s already-defined subroutine
bb3abb05 3217
345d70e3
FC
3218(W misc) Although L<attributes.pm|attributes> allows this, turning the lvalue
3219attribute on or off on a Perl subroutine that is already defined
3220does not always work properly. It may or may not do what you
3221want, depending on what code is inside the subroutine, with exact
3222details subject to change between Perl versions. Only do this
3223if you really know what you are doing.
bb3abb05 3224
885ef6f5
GG
3225=item lvalue attribute ignored after the subroutine has been defined
3226
345d70e3
FC
3227(W misc) Using the C<:lvalue> declarative syntax to make a Perl
3228subroutine an lvalue subroutine after it has been defined is
3229not permitted. To make the subroutine an lvalue subroutine,
3230add the lvalue attribute to the definition, or put the C<sub
3231foo :lvalue;> declaration before the definition.
3232
3233See also L<attributes.pm|attributes>.
885ef6f5 3234
6f1b3ab0
FC
3235=item Magical list constants are not supported
3236
3237(F) You assigned a magical array to a stash element, and then tried
3238to use the subroutine from the same slot. You are asking Perl to do
3239something it cannot do, details subject to change between Perl versions.
3240
2db62bbc 3241=item Malformed integer in [] in pack
49704364 3242
2db62bbc 3243(F) Between the brackets enclosing a numeric repeat count only digits
49704364
LW
3244are permitted. See L<perlfunc/pack>.
3245
3246=item Malformed integer in [] in unpack
3247
2db62bbc 3248(F) Between the brackets enclosing a numeric repeat count only digits
49704364
LW
3249are permitted. See L<perlfunc/pack>.
3250
6df41af2
GS
3251=item Malformed PERLLIB_PREFIX
3252
3253(F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form
3254
3255 prefix1;prefix2
3256
3257or
6df41af2
GS
3258 prefix1 prefix2
3259
be771a83
GS
3260with nonempty prefix1 and prefix2. If C<prefix1> is indeed a prefix of
3261a builtin library search path, prefix2 is substituted. The error may
3262appear if components are not found, or are too long. See
fecfaeb8 3263"PERLLIB_PREFIX" in L<perlos2>.
6df41af2 3264
2f758a16
ST
3265=item Malformed prototype for %s: %s
3266
d37a9538
ST
3267(F) You tried to use a function with a malformed prototype. The
3268syntax of function prototypes is given a brief compile-time check for
3269obvious errors like invalid characters. A more rigorous check is run
3270when the function is called.
30d9c59b
Z
3271Perhaps the function's author was trying to write a subroutine signature
3272but didn't enable that feature first (C<use feature 'signatures'>),
3273so the signature was instead interpreted as a bad prototype.
2f758a16 3274
ba210ebe
JH
3275=item Malformed UTF-8 character (%s)
3276
4d6f11e5 3277(S utf8)(F) Perl detected a string that didn't comply with UTF-8
2575c402 3278encoding rules, even though it had the UTF8 flag on.
ba210ebe 3279
2575c402
JW
3280One possible cause is that you set the UTF8 flag yourself for data that
3281you thought to be in UTF-8 but it wasn't (it was for example legacy
6903afa2 32828-bit data). To guard against this, you can use Encode::decode_utf8.
2575c402
JW
3283
3284If you use the C<:encoding(UTF-8)> PerlIO layer for input, invalid byte
3285sequences are handled gracefully, but if you use C<:utf8>, the flag is
3286set without validating the data, possibly resulting in this error
3287message.
3288
3289See also L<Encode/"Handling Malformed Data">.
901b21bf 3290
107160e2
KW
3291=item Malformed UTF-8 character immediately after '%s'
3292
3293(F) You said C<use utf8>, but the program file doesn't comply with UTF-8
3294encoding rules. The message prints out the properly encoded characters
3295just before the first bad one. If C<utf8> warnings are enabled, a
3296warning is generated that gives more details about the type of
3297malformation.
3298
bde9e88d 3299=item Malformed UTF-8 returned by \N{%s} immediately after '%s'
ff3f963a
KW
3300
3301(F) The charnames handler returned malformed UTF-8.
3302
4a5d3a93
FC
3303=item Malformed UTF-8 string in '%c' format in unpack
3304
3305(F) You tried to unpack something that didn't comply with UTF-8 encoding
3306rules and perl was unable to guess how to make more progress.
3307
f337b084
TH
3308=item Malformed UTF-8 string in pack
3309
3310(F) You tried to pack something that didn't comply with UTF-8 encoding
3311rules and perl was unable to guess how to make more progress.
3312
3313=item Malformed UTF-8 string in unpack
3314
3315(F) You tried to unpack something that didn't comply with UTF-8 encoding
3316rules and perl was unable to guess how to make more progress.
3317
4a5d3a93 3318=item Malformed UTF-16 surrogate
f337b084 3319
4a5d3a93
FC
3320(F) Perl thought it was reading UTF-16 encoded character data but while
3321doing it Perl met a malformed Unicode surrogate.
3322
30d9c59b
Z
3323=item Mandatory parameter follows optional parameter
3324
3325(F) In a subroutine signature, you wrote something like "$a = undef,
3326$b", making an earlier parameter optional and a later one mandatory.
3327Parameters are filled from left to right, so it's impossible for the
3328caller to omit an earlier one and pass a later one. If you want to act
3329as if the parameters are filled from right to left, declare the rightmost
3330optional and then shuffle the parameters around in the subroutine's body.
3331
2d88a86a
KW
3332=item Matched non-Unicode code point 0x%X against Unicode property; may
3333not be portable
3334
3335(S non_unicode) Perl allows strings to contain a superset of
3336Unicode code points; each code point may be as large as what is storable
3337in an unsigned integer on your system, but these may not be accepted by
3338other languages/systems. This message occurs when you matched a string
3339containing such a code point against a regular expression pattern, and
3340the code point was matched against a Unicode property, C<\p{...}> or
3341C<\P{...}>. Unicode properties are only defined on Unicode code points,
3342so the result of this match is undefined by Unicode, but Perl (starting
3343in v5.20) treats non-Unicode code points as if they were typical
3344unassigned Unicode ones, and matched this one accordingly. Whether a
3345given property matches these code points or not is specified in
3346L<perluniprops/Properties accessible through \p{} and \P{}>.
3347
3348This message is suppressed (unless it has been made fatal) if it is
3349immaterial to the results of the match if the code point is Unicode or
3350not. For example, the property C<\p{ASCII_Hex_Digit}> only can match
3351the 22 characters C<[0-9A-Fa-f]>, so obviously all other code points,
3352Unicode or not, won't match it. (And C<\P{ASCII_Hex_Digit}> will match
3353every code point except these 22.)
3354
3355Getting this message indicates that the outcome of the match arguably
3356should have been the opposite of what actually happened. If you think
3357that is the case, you may wish to make the C<non_unicode> warnings
3358category fatal; if you agree with Perl's decision, you may wish to turn
3359off this category.
3360
3361See L<perlunicode/Beyond Unicode code points> for more information.
3362
e0e4a6e3
FC
3363=item %s matches null string many times in regex; marked by S<<-- HERE> in
3364m/%s/
4a5d3a93
FC
3365
3366(W regexp) The pattern you've specified would be an infinite loop if the
e0e4a6e3 3367regular expression engine didn't specifically check for that. The S<<-- HERE>
9e3ec65c 3368shows whereabouts in the regular expression the problem was discovered.
4a5d3a93 3369See L<perlre>.
f337b084 3370
de42a5a9 3371=item Maximal count of pending signals (%u) exceeded
2563cec5 3372
6903afa2 3373(F) Perl aborted due to too high a number of signals pending. This
2563cec5
IZ
3374usually indicates that your operating system tried to deliver signals
3375too fast (with a very high priority), starving the perl process from
3376resources it would need to reach a point where it can process signals
6903afa2 3377safely. (See L<perlipc/"Deferred Signals (Safe Signals)">.)
2563cec5 3378
25f58aea
PN
3379=item "%s" may clash with future reserved word
3380
3381(W) This warning may be due to running a perl5 script through a perl4
3382interpreter, especially if the word that is being warned about is
3383"use" or "my".
3384
0d2487cd 3385=item '%' may not be used in pack
6df41af2
GS
3386