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fix perldiag entry for CORE::dump()
[perl5.git] / pod / perldiag.pod
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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
637494ac 219=item Array passed to stat will be coerced to a scalar%s
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220
221(W syntax) You called stat() on an array, but the array will be
222coerced to a scalar - the number of elements in the array.
223
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224=item A signature parameter must start with '$', '@' or '%'
225
226(F) Each subroutine signature parameter declaration must start with a valid
227sigil; for example:
228
229 sub foo ($a, $, $b = 1, @c) {}
230
231=item A slurpy parameter may not have a default value
232
233(F) Only scalar subroutine signature parameters may have a default value;
234for example:
235
236 sub foo ($a = 1) {} # legal
237 sub foo (@a = (1)) {} # invalid
238 sub foo (%a = (a => b)) {} # invalid
239
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240=item assertion botched: %s
241
21b5e840 242(X) The malloc package that comes with Perl had an internal failure.
a0d0e21e 243
0eacef8e 244=item Assertion %s failed: file "%s", line %d
a0d0e21e 245
21b5e840 246(X) A general assertion failed. The file in question must be examined.
a0d0e21e 247
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248=item Assigned value is not a reference
249
250(F) You tried to assign something that was not a reference to an lvalue
251reference (e.g., C<\$x = $y>). If you meant to make $x an alias to $y, use
252C<\$x = \$y>.
253
254=item Assigned value is not %s reference
255
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256(F) You tried to assign a reference to a reference constructor, but the
257two references were not of the same type. You cannot alias a scalar to
258an array, or an array to a hash; the two types must match.
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259
260 \$x = \@y; # error
261 \@x = \%y; # error
262 $y = [];
263 \$x = $y; # error; did you mean \$y?
264
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265=item Assigning non-zero to $[ is no longer possible
266
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267(F) When the "array_base" feature is disabled (e.g., under C<use v5.16;>)
268the special variable C<$[>, which is deprecated, is now a fixed zero value.
82122228 269
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270=item Assignment to both a list and a scalar
271
272(F) If you assign to a conditional operator, the 2nd and 3rd arguments
273must either both be scalars or both be lists. Otherwise Perl won't
274know which context to supply to the right side.
275
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276=item Assuming NOT a POSIX class since %s in regex; marked by S<<-- HERE> in m/%s/
277
278(W regexp) You had something like these:
279
280 [[:alnum]]
281 [[:digit:xyz]
282
283They look like they might have been meant to be the POSIX classes
284C<[:alnum:]> or C<[:digit:]>. If so, they should be written:
285
286 [[:alnum:]]
287 [[:digit:]xyz]
288
289Since these aren't legal POSIX class specifications, but are legal
290bracketed character classes, Perl treats them as the latter. In the
291first example, it matches the characters C<":">, C<"[">, C<"a">, C<"l">,
292C<"m">, C<"n">, and C<"u">.
293
294If these weren't meant to be POSIX classes, this warning message is
295spurious, and can be suppressed by reordering things, such as
296
297 [[al:num]]
298
299or
300
301 [[:munla]]
302
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303=item <> at require-statement should be quotes
304
305(F) You wrote C<< require <file> >> when you should have written
306C<require 'file'>.
307
2393f1b9 308=item Attempt to access disallowed key '%s' in a restricted hash
1b1f1335 309
49293501 310(F) The failing code has attempted to get or set a key which is not in
2393f1b9 311the current set of allowed keys of a restricted hash.
49293501 312
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313=item Attempt to bless into a freed package
314
315(F) You wrote C<bless $foo> with one argument after somehow causing
316the current package to be freed. Perl cannot figure out what to
317do, so it throws up in hands in despair.
318
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319=item Attempt to bless into a reference
320
321(F) The CLASSNAME argument to the bless() operator is expected to be
57dedab9 322the name of the package to bless the resulting object into. You've
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323supplied instead a reference to something: perhaps you wrote
324
325 bless $self, $proto;
326
327when you intended
328
329 bless $self, ref($proto) || $proto;
330
331If you actually want to bless into the stringified version
332of the reference supplied, you need to stringify it yourself, for
333example by:
334
335 bless $self, "$proto";
336
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337=item Attempt to clear deleted array
338
339(S debugging) An array was assigned to when it was being freed.
340Freed values are not supposed to be visible to Perl code. This
341can also happen if XS code calls C<av_clear> from a custom magic
342callback on the array.
343
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344=item Attempt to delete disallowed key '%s' from a restricted hash
345
346(F) The failing code attempted to delete from a restricted hash a key
347which is not in its key set.
348
349=item Attempt to delete readonly key '%s' from a restricted hash
350
351(F) The failing code attempted to delete a key whose value has been
352declared readonly from a restricted hash.
353
de42a5a9 354=item Attempt to free non-arena SV: 0x%x
a0d0e21e 355
f84fe999 356(S internal) All SV objects are supposed to be allocated from arenas
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357that will be garbage collected on exit. An SV was discovered to be
358outside any of those arenas.
a0d0e21e 359
12578ffb 360=item Attempt to free nonexistent shared string '%s'%s
bbce6d69 361
f84fe999 362(S internal) Perl maintains a reference-counted internal table of
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363strings to optimize the storage and access of hash keys and other
364strings. This indicates someone tried to decrement the reference count
365of a string that can no longer be found in the table.
bbce6d69 366
7d5b40b4 367=item Attempt to free temp prematurely: SV 0x%x
a0d0e21e 368
f84fe999 369(S debugging) Mortalized values are supposed to be freed by the
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370free_tmps() routine. This indicates that something else is freeing the
371SV before the free_tmps() routine gets a chance, which means that the
372free_tmps() routine will be freeing an unreferenced scalar when it does
373try to free it.
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374
375=item Attempt to free unreferenced glob pointers
376
f84fe999 377(S internal) The reference counts got screwed up on symbol aliases.
a0d0e21e 378
7d5b40b4 379=item Attempt to free unreferenced scalar: SV 0x%x
a0d0e21e 380
8f7e4d2c 381(S internal) Perl went to decrement the reference count of a scalar to
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382see if it would go to 0, and discovered that it had already gone to 0
383earlier, and should have been freed, and in fact, probably was freed.
384This could indicate that SvREFCNT_dec() was called too many times, or
385that SvREFCNT_inc() was called too few times, or that the SV was
386mortalized when it shouldn't have been, or that memory has been
387corrupted.
a0d0e21e 388
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389=item Attempt to pack pointer to temporary value
390
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391(W pack) You tried to pass a temporary value (like the result of a
392function, or a computed expression) to the "p" pack() template. This
393means the result contains a pointer to a location that could become
394invalid anytime, even before the end of the current statement. Use
395literals or global values as arguments to the "p" pack() template to
396avoid this warning.
84902520 397
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398=item Attempt to reload %s aborted.
399
400(F) You tried to load a file with C<use> or C<require> that failed to
401compile once already. Perl will not try to compile this file again
402unless you delete its entry from %INC. See L<perlfunc/require> and
403L<perlvar/%INC>.
404
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405=item Attempt to set length of freed array
406
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FC
407(W misc) You tried to set the length of an array which has
408been freed. You can do this by storing a reference to the
409scalar representing the last index of an array and later
410assigning through that reference. For example
1b20cd17
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411
412 $r = do {my @a; \$#a};
413 $$r = 503
414
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415=item Attempt to use reference as lvalue in substr
416
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417(W substr) You supplied a reference as the first argument to substr()
418used as an lvalue, which is pretty strange. Perhaps you forgot to
419dereference it first. See L<perlfunc/substr>.
b7a902f4 420
c9680906 421=item Attribute "locked" is deprecated, and will disappear in Perl 5.28
c32124fe 422
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FC
423(D deprecated) You have used the attributes pragma to modify the
424"locked" attribute on a code reference. The :locked attribute is
425obsolete, has had no effect since 5005 threads were removed, and
c9680906 426will be removed in a Perl 5.28.
c32124fe 427
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FC
428=item Attribute prototype(%s) discards earlier prototype attribute in same sub
429
430(W misc) A sub was declared as sub foo : prototype(A) : prototype(B) {}, for
431example. Since each sub can only have one prototype, the earlier
432declaration(s) are discarded while the last one is applied.
433
c9680906 434=item Attribute "unique" is deprecated, and will disappear in Perl 5.28
f1a3ce43 435
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FC
436(D deprecated) You have used the attributes pragma to modify
437the "unique" attribute on an array, hash or scalar reference.
438The :unique attribute has had no effect since Perl 5.8.8, and
c9680906 439will be removed in a Perl 5.28.
f1a3ce43 440
ccce04a4
FC
441=item av_reify called on tied array
442
443(S debugging) This indicates that something went wrong and Perl got I<very>
444confused about C<@_> or C<@DB::args> being tied.
445
de42a5a9 446=item Bad arg length for %s, is %u, should be %d
a0d0e21e 447
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448(F) You passed a buffer of the wrong size to one of msgctl(), semctl()
449or shmctl(). In C parlance, the correct sizes are, respectively,
5f05dabc 450S<sizeof(struct msqid_ds *)>, S<sizeof(struct semid_ds *)>, and
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LW
451S<sizeof(struct shmid_ds *)>.
452
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453=item Bad evalled substitution pattern
454
496a33f5 455(F) You've used the C</e> switch to evaluate the replacement for a
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456substitution, but perl found a syntax error in the code to evaluate,
457most likely an unexpected right brace '}'.
458
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459=item Bad filehandle: %s
460
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461(F) A symbol was passed to something wanting a filehandle, but the
462symbol has no filehandle associated with it. Perhaps you didn't do an
463open(), or did it in another package.
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464
465=item Bad free() ignored
466
be771a83 467(S malloc) An internal routine called free() on something that had never
fa816bf3 468been malloc()ed in the first place. Mandatory, but can be disabled by
9ea8bc6d 469setting environment variable C<PERL_BADFREE> to 0.
33c8a3fe 470
9ea8bc6d 471This message can be seen quite often with DB_File on systems with "hard"
6903afa2 472dynamic linking, like C<AIX> and C<OS/2>. It is a bug of C<Berkeley DB>
be771a83 473which is left unnoticed if C<DB> uses I<forgiving> system malloc().
a0d0e21e 474
aa689395
PP
475=item Bad hash
476
477(P) One of the internal hash routines was passed a null HV pointer.
478
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479=item Badly placed ()'s
480
481(A) You've accidentally run your script through B<csh> instead
482of Perl. Check the #! line, or manually feed your script into
483Perl yourself.
484
a7cb8dae 485=item Bad name after %s
a0d0e21e 486
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487(F) You started to name a symbol by using a package prefix, and then
488didn't finish the symbol. In particular, you can't interpolate outside
489of quotes, so
a0d0e21e
LW
490
491 $var = 'myvar';
492 $sym = mypack::$var;
493
494is not the same as
495
496 $var = 'myvar';
497 $sym = "mypack::$var";
498
88e1f1a2
JV
499=item Bad plugin affecting keyword '%s'
500
501(F) An extension using the keyword plugin mechanism violated the
502plugin API.
503
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504=item Bad realloc() ignored
505
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FC
506(S malloc) An internal routine called realloc() on something that
507had never been malloc()ed in the first place. Mandatory, but can
508be disabled by setting the environment variable C<PERL_BADFREE> to 1.
4ad56ec9 509
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510=item Bad symbol for array
511
512(P) An internal request asked to add an array entry to something that
513wasn't a symbol table entry.
514
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SP
515=item Bad symbol for dirhandle
516
517(P) An internal request asked to add a dirhandle entry to something
518that wasn't a symbol table entry.
519
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520=item Bad symbol for filehandle
521
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522(P) An internal request asked to add a filehandle entry to something
523that wasn't a symbol table entry.
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LW
524
525=item Bad symbol for hash
526
527(P) An internal request asked to add a hash entry to something that
528wasn't a symbol table entry.
529
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FC
530=item Bad symbol for scalar
531
532(P) An internal request asked to add a scalar entry to something that
533wasn't a symbol table entry.
534
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535=item Bareword found in conditional
536
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537(W bareword) The compiler found a bareword where it expected a
538conditional, which often indicates that an || or && was parsed as part
539of the last argument of the previous construct, for example:
34d09196
GS
540
541 open FOO || die;
542
be771a83
GS
543It may also indicate a misspelled constant that has been interpreted as
544a bareword:
34d09196
GS
545
546 use constant TYPO => 1;
547 if (TYOP) { print "foo" }
548
549The C<strict> pragma is useful in avoiding such errors.
550
a52f2cce
NC
551=item Bareword in require contains "%s"
552
a52f2cce
NC
553=item Bareword in require maps to disallowed filename "%s"
554
09eb1f39 555=item Bareword in require maps to empty filename
5bad2b39 556
a52f2cce 557(F) The bareword form of require has been invoked with a filename which could
d4e5761f 558not have been generated by a valid bareword permitted by the parser. You
a52f2cce
NC
559shouldn't be able to get this error from Perl code, but XS code may throw it
560if it passes an invalid module name to C<Perl_load_module>.
561
5bad2b39
DM
562=item Bareword in require must not start with a double-colon: "%s"
563
564(F) In C<require Bare::Word>, the bareword is not allowed to start with a
d4e5761f 565double-colon. Write C<require ::Foo::Bar> as C<require Foo::Bar> instead.
5bad2b39 566
6df41af2
GS
567=item Bareword "%s" not allowed while "strict subs" in use
568
569(F) With "strict subs" in use, a bareword is only allowed as a
be771a83
GS
570subroutine identifier, in curly brackets or to the left of the "=>"
571symbol. Perhaps you need to predeclare a subroutine?
6df41af2
GS
572
573=item Bareword "%s" refers to nonexistent package
574
be771a83
GS
575(W bareword) You used a qualified bareword of the form C<Foo::>, but the
576compiler saw no other uses of that namespace before that point. Perhaps
577you need to predeclare a package?
6df41af2 578
a0d0e21e
LW
579=item BEGIN failed--compilation aborted
580
be771a83
GS
581(F) An untrapped exception was raised while executing a BEGIN
582subroutine. Compilation stops immediately and the interpreter is
583exited.
a0d0e21e 584
68dc0745
PP
585=item BEGIN not safe after errors--compilation aborted
586
587(F) Perl found a C<BEGIN {}> subroutine (or a C<use> directive, which
be771a83
GS
588implies a C<BEGIN {}>) after one or more compilation errors had already
589occurred. Since the intended environment for the C<BEGIN {}> could not
590be guaranteed (due to the errors), and since subsequent code likely
591depends on its correct operation, Perl just gave up.
68dc0745 592
c782d7ee 593=item \%d better written as $%d
6df41af2 594
be771a83
GS
595(W syntax) Outside of patterns, backreferences live on as variables.
596The use of backslashes is grandfathered on the right-hand side of a
597substitution, but stylistically it's better to use the variable form
598because other Perl programmers will expect it, and it works better if
599there are more than 9 backreferences.
6df41af2 600
252aa082
JH
601=item Binary number > 0b11111111111111111111111111111111 non-portable
602
e476b1b5 603(W portable) The binary number you specified is larger than 2**32-1
9e24b6e2
JH
604(4294967295) and therefore non-portable between systems. See
605L<perlport> for more on portability concerns.
252aa082 606
69282e91 607=item bind() on closed socket %s
a0d0e21e 608
be771a83
GS
609(W closed) You tried to do a bind on a closed socket. Did you forget to
610check the return value of your socket() call? See L<perlfunc/bind>.
a0d0e21e 611
c289d2f7
JH
612=item binmode() on closed filehandle %s
613
614(W unopened) You tried binmode() on a filehandle that was never opened.
4dcecea4 615Check your control flow and number of arguments.
c289d2f7 616
c5a0f51a
JH
617=item Bit vector size > 32 non-portable
618
e476b1b5 619(W portable) Using bit vector sizes larger than 32 is non-portable.
c5a0f51a 620
043c750c 621=item Bizarre copy of %s
4633a7c4 622
be771a83 623(P) Perl detected an attempt to copy an internal value that is not
ab830aa0 624copiable.
4633a7c4 625
5a25739d
FC
626=item Bizarre SvTYPE [%d]
627
434f489b 628(P) When starting a new thread or returning values from a thread, Perl
5a25739d
FC
629encountered an invalid data type.
630
b927b7e9 631=item Both or neither range ends should be Unicode in regex; marked by
6e8a73f2 632S<<-- HERE> in m/%s/
b927b7e9
KW
633
634(W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
635
636In a bracketed character class in a regular expression pattern, you
637had a range which has exactly one end of it specified using C<\N{}>, and
638the other end is specified using a non-portable mechanism. Perl treats
639the range as a Unicode range, that is, all the characters in it are
640considered to be the Unicode characters, and which may be different code
641points on some platforms Perl runs on. For example, C<[\N{U+06}-\x08]>
642is treated as if you had instead said C<[\N{U+06}-\N{U+08}]>, that is it
643matches the characters whose code points in Unicode are 6, 7, and 8.
644But that C<\x08> might indicate that you meant something different, so
645the warning gets raised.
646
f675dbe5
CB
647=item Buffer overflow in prime_env_iter: %s
648
be771a83
GS
649(W internal) A warning peculiar to VMS. While Perl was preparing to
650iterate over %ENV, it encountered a logical name or symbol definition
651which was too long, so it was truncated to the string shown.
f675dbe5 652
a0d0e21e
LW
653=item Callback called exit
654
4929bf7b 655(F) A subroutine invoked from an external package via call_sv()
a0d0e21e
LW
656exited by calling exit.
657
6df41af2 658=item %s() called too early to check prototype
f675dbe5 659
be771a83
GS
660(W prototype) You've called a function that has a prototype before the
661parser saw a definition or declaration for it, and Perl could not check
662that the call conforms to the prototype. You need to either add an
663early prototype declaration for the subroutine in question, or move the
664subroutine definition ahead of the call to get proper prototype
665checking. Alternatively, if you are certain that you're calling the
666function correctly, you may put an ampersand before the name to avoid
667the warning. See L<perlsub>.
f675dbe5 668
0c7df902
JH
669=item Cannot chr %f
670
671(F) You passed an invalid number (like an infinity or not-a-number) to C<chr>.
672
5dee29d4 673=item Cannot compress %f in pack
0c7df902 674
5dee29d4
JH
675(F) You tried compressing an infinity or not-a-number as an unsigned
676integer with BER, which makes no sense.
0c7df902 677
49704364 678=item Cannot compress integer in pack
0258719b 679
717feafc
JH
680(F) An argument to pack("w",...) was too large to compress.
681The BER compressed integer format can only be used with positive
682integers, and you attempted to compress a very large number (> 1e308).
683See L<perlfunc/pack>.
0258719b 684
49704364 685=item Cannot compress negative numbers in pack
0258719b
NC
686
687(F) An argument to pack("w",...) was negative. The BER compressed integer
688format can only be used with positive integers. See L<perlfunc/pack>.
689
5c1f4d79
NC
690=item Cannot convert a reference to %s to typeglob
691
6903afa2
FC
692(F) You manipulated Perl's symbol table directly, stored a reference
693in it, then tried to access that symbol via conventional Perl syntax.
694The access triggers Perl to autovivify that typeglob, but it there is
695no legal conversion from that type of reference to a typeglob.
5c1f4d79 696
4040665a 697=item Cannot copy to %s
ba2fdce6
NC
698
699(P) Perl detected an attempt to copy a value to an internal type that cannot
4dcecea4 700be directly assigned to.
ba2fdce6 701
b5d97229
RGS
702=item Cannot find encoding "%s"
703
704(S io) You tried to apply an encoding that did not exist to a filehandle,
705either with open() or binmode().
706
0c7df902
JH
707=item Cannot pack %f with '%c'
708
5dee29d4 709(F) You tried converting an infinity or not-a-number to an integer,
0c7df902
JH
710which makes no sense.
711
712=item Cannot printf %f with '%c'
713
714(F) You tried printing an infinity or not-a-number as a character (%c),
715which makes no sense. Maybe you meant '%s', or just stringifying it?
716
7355df7e
FC
717=item Cannot set tied @DB::args
718
719(F) C<caller> tried to set C<@DB::args>, but found it tied. Tying C<@DB::args>
720is not supported. (Before this error was added, it used to crash.)
721
ce65bc73
FC
722=item Cannot tie unreifiable array
723
724(P) You somehow managed to call C<tie> on an array that does not
725keep a reference count on its arguments and cannot be made to
726do so. Such arrays are not even supposed to be accessible to
727Perl code, but are only used internally.
728
46e58bd2
AC
729=item Cannot yet reorder sv_catpvfn() arguments from va_list
730
731(F) Some XS code tried to use C<sv_catpvfn()> or a related function with a
732format string that specifies explicit indexes for some of the elements, and
d4e5761f
FC
733using a C-style variable-argument list (a C<va_list>). This is not currently
734supported. XS authors wanting to do this must instead construct a C array
735of C<SV*> scalars containing the arguments.
46e58bd2 736
96ebfdd7
RK
737=item Can only compress unsigned integers in pack
738
739(F) An argument to pack("w",...) was not an integer. The BER compressed
740integer format can only be used with positive integers, and you attempted
741to compress something else. See L<perlfunc/pack>.
742
a0d0e21e
LW
743=item Can't bless non-reference value
744
745(F) Only hard references may be blessed. This is how Perl "enforces"
746encapsulation of objects. See L<perlobj>.
747
dc57907a
RGS
748=item Can't "break" in a loop topicalizer
749
0d863452 750(F) You called C<break>, but you're in a C<foreach> block rather than
6903afa2 751a C<given> block. You probably meant to use C<next> or C<last>.
0d863452
RH
752
753=item Can't "break" outside a given block
dc57907a 754
0d863452
RH
755(F) You called C<break>, but you're not inside a C<given> block.
756
6df41af2
GS
757=item Can't call method "%s" on an undefined value
758
759(F) You used the syntax of a method call, but the slot filled by the
be771a83
GS
760object reference or package name contains an undefined value. Something
761like this will reproduce the error:
6df41af2
GS
762
763 $BADREF = undef;
764 process $BADREF 1,2,3;
765 $BADREF->process(1,2,3);
766
a0d0e21e
LW
767=item Can't call method "%s" on unblessed reference
768
54310121 769(F) A method call must know in what package it's supposed to run. It
be771a83
GS
770ordinarily finds this out from the object reference you supply, but you
771didn't supply an object reference in this case. A reference isn't an
772object reference until it has been blessed. See L<perlobj>.
a0d0e21e
LW
773
774=item Can't call method "%s" without a package or object reference
775
776(F) You used the syntax of a method call, but the slot filled by the
be771a83
GS
777object reference or package name contains an expression that returns a
778defined value which is neither an object reference nor a package name.
72b5445b
GS
779Something like this will reproduce the error:
780
781 $BADREF = 42;
782 process $BADREF 1,2,3;
783 $BADREF->process(1,2,3);
784
dfe378f1
FC
785=item Can't call mro_isa_changed_in() on anonymous symbol table
786
787(P) Perl got confused as to whether a hash was a plain hash or a
788symbol table hash when trying to update @ISA caches.
789
2bf7e7b2
FC
790=item Can't call mro_method_changed_in() on anonymous symbol table
791
792(F) An XS module tried to call C<mro_method_changed_in> on a hash that was
793not attached to the symbol table.
794
a0d0e21e
LW
795=item Can't chdir to %s
796
f703fc96 797(F) You called C<perl -x/foo/bar>, but F</foo/bar> is not a directory
a0d0e21e
LW
798that you can chdir to, possibly because it doesn't exist.
799
0545a864 800=item Can't check filesystem of script "%s" for nosuid
104d25b7 801
be771a83
GS
802(P) For some reason you can't check the filesystem of the script for
803nosuid.
104d25b7 804
22e74366 805=item Can't coerce %s to %s in %s
a0d0e21e
LW
806
807(F) Certain types of SVs, in particular real symbol table entries
55497cff 808(typeglobs), can't be forced to stop being what they are. So you can't
a0d0e21e
LW
809say things like:
810
811 *foo += 1;
812
813You CAN say
814
815 $foo = *foo;
816 $foo += 1;
817
818but then $foo no longer contains a glob.
819
0d863452 820=item Can't "continue" outside a when block
dc57907a 821
0d863452
RH
822(F) You called C<continue>, but you're not inside a C<when>
823or C<default> block.
824
a0d0e21e
LW
825=item Can't create pipe mailbox
826
be771a83
GS
827(P) An error peculiar to VMS. The process is suffering from exhausted
828quotas or other plumbing problems.
a0d0e21e 829
eb64745e
GS
830=item Can't declare %s in "%s"
831
30c282f6
NC
832(F) Only scalar, array, and hash variables may be declared as "my", "our" or
833"state" variables. They must have ordinary identifiers as names.
a0d0e21e 834
fc7debfb
FC
835=item Can't "default" outside a topicalizer
836
837(F) You have used a C<default> block that is neither inside a
838C<foreach> loop nor a C<given> block. (Note that this error is
839issued on exit from the C<default> block, so you won't get the
840error if you use an explicit C<continue>.)
841
1e85b658
DM
842=item Can't determine class of operator %s, assuming BASEOP
843
844(S) This warning indicates something wrong in the internals of perl.
845Perl was trying to find the class (e.g. LISTOP) of a particular OP,
846and was unable to do so. This is likely to be due to a bug in the perl
847internals, or due to a bug in XS code which manipulates perl optrees.
848
a2162cd9
FC
849=item Can't do inplace edit: %s is not a regular file
850
851(S inplace) You tried to use the B<-i> switch on a special file, such as
852a file in /dev, a FIFO or an uneditable directory. The file was ignored.
853
854=item Can't do inplace edit on %s: %s
855
856(S inplace) The creation of the new file failed for the indicated
857reason.
858
859=item Can't do inplace edit without backup
860
861(F) You're on a system such as MS-DOS that gets confused if you try
862reading from a deleted (but still opened) file. You have to say
863C<-i.bak>, or some such.
864
865=item Can't do inplace edit: %s would not be unique
866
867(S inplace) Your filesystem does not support filenames longer than 14
868characters and Perl was unable to create a unique filename during
869inplace editing with the B<-i> switch. The file was ignored.
870
ab0b796c
KW
871=item Can't do %s("%s") on non-UTF-8 locale; resolved to "%s".
872
873(W locale) You are 1) running under "C<use locale>"; 2) the current
874locale is not a UTF-8 one; 3) you tried to do the designated case-change
875operation on the specified Unicode character; and 4) the result of this
876operation would mix Unicode and locale rules, which likely conflict.
877Mixing of different rule types is forbidden, so the operation was not
878done; instead the result is the indicated value, which is the best
879available that uses entirely Unicode rules. That turns out to almost
880always be the original character, unchanged.
881
882It is generally a bad idea to mix non-UTF-8 locales and Unicode, and
883this issue is one of the reasons why. This warning is raised when
884Unicode rules would normally cause the result of this operation to
885contain a character that is in the range specified by the locale,
8860..255, and hence is subject to the locale's rules, not Unicode's.
887
888If you are using locale purely for its characteristics related to things
889like its numeric and time formatting (and not C<LC_CTYPE>), consider
890using a restricted form of the locale pragma (see L<perllocale/The "use
891locale" pragma>) like "S<C<use locale ':not_characters'>>".
892
893Note that failed case-changing operations done as a result of
894case-insensitive C</i> regular expression matching will show up in this
895warning as having the C<fc> operation (as that is what the regular
896expression engine calls behind the scenes.)
897
a0d0e21e
LW
898=item Can't do waitpid with flags
899
be771a83
GS
900(F) This machine doesn't have either waitpid() or wait4(), so only
901waitpid() without flags is emulated.
a0d0e21e 902
a0d0e21e
LW
903=item Can't emulate -%s on #! line
904
be771a83
GS
905(F) The #! line specifies a switch that doesn't make sense at this
906point. For example, it'd be kind of silly to put a B<-x> on the #!
907line.
a0d0e21e 908
1109a392
MHM
909=item Can't %s %s-endian %ss on this platform
910
911(F) Your platform's byte-order is neither big-endian nor little-endian,
912or it has a very strange pointer size. Packing and unpacking big- or
913little-endian floating point values and pointers may not be possible.
914See L<perlfunc/pack>.
915
a0d0e21e
LW
916=item Can't exec "%s": %s
917
d1be9408 918(W exec) A system(), exec(), or piped open call could not execute the
be771a83
GS
919named program for the indicated reason. Typical reasons include: the
920permissions were wrong on the file, the file wasn't found in
921C<$ENV{PATH}>, the executable in question was compiled for another
922architecture, or the #! line in a script points to an interpreter that
923can't be run for similar reasons. (Or maybe your system doesn't support
924#! at all.)
a0d0e21e
LW
925
926=item Can't exec %s
927
be771a83
GS
928(F) Perl was trying to execute the indicated program for you because
929that's what the #! line said. If that's not what you wanted, you may
930need to mention "perl" on the #! line somewhere.
a0d0e21e
LW
931
932=item Can't execute %s
933
be771a83
GS
934(F) You used the B<-S> switch, but the copies of the script to execute
935found in the PATH did not have correct permissions.
2a92aaa0 936
6df41af2 937=item Can't find an opnumber for "%s"
2a92aaa0 938
be771a83
GS
939(F) A string of a form C<CORE::word> was given to prototype(), but there
940is no builtin with the name C<word>.
6df41af2
GS
941
942=item Can't find label %s
943
be771a83
GS
944(F) You said to goto a label that isn't mentioned anywhere that it's
945possible for us to go to. See L<perlfunc/goto>.
2a92aaa0
GS
946
947=item Can't find %s on PATH
948
be771a83
GS
949(F) You used the B<-S> switch, but the script to execute could not be
950found in the PATH.
a0d0e21e 951
6df41af2 952=item Can't find %s on PATH, '.' not in PATH
a0d0e21e 953
be771a83
GS
954(F) You used the B<-S> switch, but the script to execute could not be
955found in the PATH, or at least not with the correct permissions. The
956script exists in the current directory, but PATH prohibits running it.
a0d0e21e
LW
957
958=item Can't find string terminator %s anywhere before EOF
959
be771a83
GS
960(F) Perl strings can stretch over multiple lines. This message means
961that the closing delimiter was omitted. Because bracketed quotes count
962nesting levels, the following is missing its final parenthesis:
a0d0e21e 963
fb73857a
PP
964 print q(The character '(' starts a side comment.);
965
97b3d10f 966If you're getting this error from a here-document, you may have
b6b8cb97
FC
967included unseen whitespace before or after your closing tag or there
968may not be a linebreak after it. A good programmer's editor will have
969a way to help you find these characters (or lack of characters). See
970L<perlop> for the full details on here-documents.
a0d0e21e 971
660a4616
ST
972=item Can't find Unicode property definition "%s"
973
29f52644
KW
974=item Can't find Unicode property definition "%s" in regex; marked by <-- HERE in m/%s/
975
976(F) The named property which you specified via C<\p> or C<\P> is not one
977known to Perl. Perhaps you misspelled the name? See
e1b711da 978L<perluniprops/Properties accessible through \p{} and \P{}>
29f52644
KW
979for a complete list of available official
980properties. If it is a
981L<user-defined property|perlunicode/User-Defined Character Properties>
982it must have been defined by the time the regular expression is
983matched.
984
985If you didn't mean to use a Unicode property, escape the C<\p>, either
986by C<\\p> (just the C<\p>) or by C<\Q\p> (the rest of the string, or
5f8ad6b6 987until C<\E>).
660a4616 988
b3647a36 989=item Can't fork: %s
a0d0e21e 990
be771a83
GS
991(F) A fatal error occurred while trying to fork while opening a
992pipeline.
a0d0e21e 993
b3647a36
SR
994=item Can't fork, trying again in 5 seconds
995
c973c02e 996(W pipe) A fork in a piped open failed with EAGAIN and will be retried
b3647a36
SR
997after five seconds.
998
748a9306
LW
999=item Can't get filespec - stale stat buffer?
1000
be771a83
GS
1001(S) A warning peculiar to VMS. This arises because of the difference
1002between access checks under VMS and under the Unix model Perl assumes.
1003Under VMS, access checks are done by filename, rather than by bits in
1004the stat buffer, so that ACLs and other protections can be taken into
1005account. Unfortunately, Perl assumes that the stat buffer contains all
1006the necessary information, and passes it, instead of the filespec, to
2fe2bdfd 1007the access-checking routine. It will try to retrieve the filespec using
be771a83
GS
1008the device name and FID present in the stat buffer, but this works only
1009if you haven't made a subsequent call to the CRTL stat() routine,
1010because the device name is overwritten with each call. If this warning
2fe2bdfd
FC
1011appears, the name lookup failed, and the access-checking routine gave up
1012and returned FALSE, just to be conservative. (Note: The access-checking
be771a83
GS
1013routine knows about the Perl C<stat> operator and file tests, so you
1014shouldn't ever see this warning in response to a Perl command; it arises
1015only if some internal code takes stat buffers lightly.)
748a9306 1016
a0d0e21e
LW
1017=item Can't get pipe mailbox device name
1018
be771a83
GS
1019(P) An error peculiar to VMS. After creating a mailbox to act as a
1020pipe, Perl can't retrieve its name for later use.
a0d0e21e
LW
1021
1022=item Can't get SYSGEN parameter value for MAXBUF
1023
748a9306
LW
1024(P) An error peculiar to VMS. Perl asked $GETSYI how big you want your
1025mailbox buffers to be, and didn't get an answer.
a0d0e21e 1026
6df41af2 1027=item Can't "goto" into the middle of a foreach loop
a0d0e21e 1028
be771a83
GS
1029(F) A "goto" statement was executed to jump into the middle of a foreach
1030loop. You can't get there from here. See L<perlfunc/goto>.
6df41af2
GS
1031
1032=item Can't "goto" out of a pseudo block
1033
be771a83
GS
1034(F) A "goto" statement was executed to jump out of what might look like
1035a block, except that it isn't a proper block. This usually occurs if
1036you tried to jump out of a sort() block or subroutine, which is a no-no.
1037See L<perlfunc/goto>.
a0d0e21e 1038
5a25739d
FC
1039=item Can't goto subroutine from an eval-%s
1040
1041(F) The "goto subroutine" call can't be used to jump out of an eval
1042"string" or block.
1043
9850bf21 1044=item Can't goto subroutine from a sort sub (or similar callback)
cd299c6e 1045
9850bf21
RH
1046(F) The "goto subroutine" call can't be used to jump out of the
1047comparison sub for a sort(), or from a similar callback (such
1048as the reduce() function in List::Util).
1049
6df41af2
GS
1050=item Can't goto subroutine outside a subroutine
1051
be771a83
GS
1052(F) The deeply magical "goto subroutine" call can only replace one
1053subroutine call for another. It can't manufacture one out of whole
1054cloth. In general you should be calling it out of only an AUTOLOAD
1055routine anyway. See L<perlfunc/goto>.
6df41af2 1056
0b5b802d
GS
1057=item Can't ignore signal CHLD, forcing to default
1058
be771a83
GS
1059(W signal) Perl has detected that it is being run with the SIGCHLD
1060signal (sometimes known as SIGCLD) disabled. Since disabling this
1061signal will interfere with proper determination of exit status of child
1062processes, Perl has reset the signal to its default value. This
1063situation typically indicates that the parent program under which Perl
1064may be running (e.g. cron) is being very careless.
0b5b802d 1065
e2c0f81f
DG
1066=item Can't kill a non-numeric process ID
1067
1068(F) Process identifiers must be (signed) integers. It is a fatal error to
1069attempt to kill() an undefined, empty-string or otherwise non-numeric
1070process identifier.
1071
6df41af2 1072=item Can't "last" outside a loop block
4633a7c4 1073
6df41af2 1074(F) A "last" statement was executed to break out of the current block,
be771a83
GS
1075except that there's this itty bitty problem called there isn't a current
1076block. Note that an "if" or "else" block doesn't count as a "loopish"
1077block, as doesn't a block given to sort(), map() or grep(). You can
1078usually double the curlies to get the same effect though, because the
1079inner curlies will be considered a block that loops once. See
1080L<perlfunc/last>.
4633a7c4 1081
2c7d6b9c
RGS
1082=item Can't linearize anonymous symbol table
1083
1084(F) Perl tried to calculate the method resolution order (MRO) of a
1085package, but failed because the package stash has no name.
1086
b8170e59
JB
1087=item Can't load '%s' for module %s
1088
6903afa2
FC
1089(F) The module you tried to load failed to load a dynamic extension.
1090This may either mean that you upgraded your version of perl to one
1091that is incompatible with your old dynamic extensions (which is known
1092to happen between major versions of perl), or (more likely) that your
1093dynamic extension was built against an older version of the library
1094that is installed on your system. You may need to rebuild your old
1095dynamic extensions.
b8170e59 1096
748a9306
LW
1097=item Can't localize lexical variable %s
1098
2ba9eb46 1099(F) You used local on a variable name that was previously declared as a
b7e4ecc1
FC
1100lexical variable using "my" or "state". This is not allowed. If you
1101want to localize a package variable of the same name, qualify it with
1102the package name.
748a9306 1103
6df41af2 1104=item Can't localize through a reference
4727527e 1105
6df41af2
GS
1106(F) You said something like C<local $$ref>, which Perl can't currently
1107handle, because when it goes to restore the old value of whatever $ref
be771a83 1108pointed to after the scope of the local() is finished, it can't be sure
64977eb6 1109that $ref will still be a reference.
4727527e 1110
ea071790 1111=item Can't locate %s
ec889f3a 1112
fa816bf3
FC
1113(F) You said to C<do> (or C<require>, or C<use>) a file that couldn't be found.
1114Perl looks for the file in all the locations mentioned in @INC, unless
1115the file name included the full path to the file. Perhaps you need
1116to set the PERL5LIB or PERL5OPT environment variable to say where the
1117extra library is, or maybe the script needs to add the library name
be771a83
GS
1118to @INC. Or maybe you just misspelled the name of the file. See
1119L<perlfunc/require> and L<lib>.
a0d0e21e 1120
6df41af2
GS
1121=item Can't locate auto/%s.al in @INC
1122
be771a83
GS
1123(F) A function (or method) was called in a package which allows
1124autoload, but there is no function to autoload. Most probable causes
1125are a misprint in a function/method name or a failure to C<AutoSplit>
1126the file, say, by doing C<make install>.
6df41af2 1127
b8170e59
JB
1128=item Can't locate loadable object for module %s in @INC
1129
1130(F) The module you loaded is trying to load an external library, like
d70d8e57 1131for example, F<foo.so> or F<bar.dll>, but the L<DynaLoader> module was
b8170e59
JB
1132unable to locate this library. See L<DynaLoader>.
1133
a0d0e21e
LW
1134=item Can't locate object method "%s" via package "%s"
1135
1136(F) You called a method correctly, and it correctly indicated a package
1137functioning as a class, but that package doesn't define that particular
2ba9eb46 1138method, nor does any of its base classes. See L<perlobj>.
a0d0e21e 1139
8af56b9d
FC
1140=item Can't locate object method "%s" via package "%s" (perhaps you forgot
1141to load "%s"?)
1142
1143(F) You called a method on a class that did not exist, and the method
1144could not be found in UNIVERSAL. This often means that a method
1145requires a package that has not been loaded.
1146
a0d0e21e
LW
1147=item Can't locate package %s for @%s::ISA
1148
be771a83
GS
1149(W syntax) The @ISA array contained the name of another package that
1150doesn't seem to exist.
a0d0e21e 1151
2f7da168
RK
1152=item Can't locate PerlIO%s
1153
1154(F) You tried to use in open() a PerlIO layer that does not exist,
1155e.g. open(FH, ">:nosuchlayer", "somefile").
1156
f4ad53f4 1157=item Can't make list assignment to %ENV on this system
3e3baf6d 1158
be771a83
GS
1159(F) List assignment to %ENV is not supported on some systems, notably
1160VMS.
3e3baf6d 1161
cd40cd58
NC
1162=item Can't make loaded symbols global on this platform while loading %s
1163
ff9c1ae8 1164(S) A module passed the flag 0x01 to DynaLoader::dl_load_file() to request
cd40cd58
NC
1165that symbols from the stated file are made available globally within the
1166process, but that functionality is not available on this platform. Whilst
1167the module likely will still work, this may prevent the perl interpreter
1168from loading other XS-based extensions which need to link directly to
1169functions defined in the C or XS code in the stated file.
1170
a0d0e21e
LW
1171=item Can't modify %s in %s
1172
be771a83
GS
1173(F) You aren't allowed to assign to the item indicated, or otherwise try
1174to change it, such as with an auto-increment.
a0d0e21e 1175
54310121 1176=item Can't modify nonexistent substring
a0d0e21e
LW
1177
1178(P) The internal routine that does assignment to a substr() was handed
1179a NULL.
1180
0f948285 1181=item Can't modify non-lvalue subroutine call of &%s
6df41af2
GS
1182
1183(F) Subroutines meant to be used in lvalue context should be declared as
2fe2bdfd 1184such. See L<perlsub/"Lvalue subroutines">.
6df41af2 1185
cf6e1fa1
FC
1186=item Can't modify reference to %s in %s assignment
1187
1188(F) Only a limited number of constructs can be used as the argument to a
1189reference constructor on the left-hand side of an assignment, and what
1190you used was not one of them. See L<perlref/Assigning to References>.
1191
1192=item Can't modify reference to localized parenthesized array in list
1193assignment
1194
1195(F) Assigning to C<\local(@array)> or C<\(local @array)> is not supported, as
1196it is not clear exactly what it should do. If you meant to make @array
1197refer to some other array, use C<\@array = \@other_array>. If you want to
1198make the elements of @array aliases of the scalars referenced on the
1199right-hand side, use C<\(@array) = @scalar_refs>.
1200
1201=item Can't modify reference to parenthesized hash in list assignment
1202
1203(F) Assigning to C<\(%hash)> is not supported. If you meant to make %hash
1204refer to some other hash, use C<\%hash = \%other_hash>. If you want to
1205make the elements of %hash into aliases of the scalars referenced on the
1206right-hand side, use a hash slice: C<\@hash{@keys} = @those_scalar_refs>.
1207
5f05dabc 1208=item Can't msgrcv to read-only var
a0d0e21e 1209
5f05dabc 1210(F) The target of a msgrcv must be modifiable to be used as a receive
a0d0e21e
LW
1211buffer.
1212
6df41af2
GS
1213=item Can't "next" outside a loop block
1214
1215(F) A "next" statement was executed to reiterate the current block, but
1216there isn't a current block. Note that an "if" or "else" block doesn't
be771a83
GS
1217count as a "loopish" block, as doesn't a block given to sort(), map() or
1218grep(). You can usually double the curlies to get the same effect
1219though, because the inner curlies will be considered a block that loops
1220once. See L<perlfunc/next>.
6df41af2 1221
a0d0e21e
LW
1222=item Can't open %s: %s
1223
c47ff5f1 1224(S inplace) The implicit opening of a file through use of the C<< <> >>
08e9d68e 1225filehandle, either implicitly under the C<-n> or C<-p> command-line
46fa9b26
FC
1226switches, or explicitly, failed for the indicated reason. Usually
1227this is because you don't have read permission for a file which
1228you named on the command line.
1229
1230(F) You tried to call perl with the B<-e> switch, but F</dev/null> (or
1231your operating system's equivalent) could not be opened.
a0d0e21e 1232
9a869a14
RGS
1233=item Can't open a reference
1234
1235(W io) You tried to open a scalar reference for reading or writing,
2fe2bdfd 1236using the 3-arg open() syntax:
9a869a14
RGS
1237
1238 open FH, '>', $ref;
1239
1240but your version of perl is compiled without perlio, and this form of
1241open is not supported.
1242
a0d0e21e
LW
1243=item Can't open bidirectional pipe
1244
be771a83
GS
1245(W pipe) You tried to say C<open(CMD, "|cmd|")>, which is not supported.
1246You can try any of several modules in the Perl library to do this, such
1247as IPC::Open2. Alternately, direct the pipe's output to a file using
1248">", and then read it in under a different file handle.
a0d0e21e 1249
748a9306
LW
1250=item Can't open error file %s as stderr
1251
be771a83
GS
1252(F) An error peculiar to VMS. Perl does its own command line
1253redirection, and couldn't open the file specified after '2>' or '2>>' on
1254the command line for writing.
748a9306
LW
1255
1256=item Can't open input file %s as stdin
1257
be771a83
GS
1258(F) An error peculiar to VMS. Perl does its own command line
1259redirection, and couldn't open the file specified after '<' on the
1260command line for reading.
748a9306
LW
1261
1262=item Can't open output file %s as stdout
1263
be771a83
GS
1264(F) An error peculiar to VMS. Perl does its own command line
1265redirection, and couldn't open the file specified after '>' or '>>' on
1266the command line for writing.
748a9306
LW
1267
1268=item Can't open output pipe (name: %s)
1269
be771a83
GS
1270(P) An error peculiar to VMS. Perl does its own command line
1271redirection, and couldn't open the pipe into which to send data destined
1272for stdout.
748a9306 1273
3b1cf97d 1274=item Can't open perl script "%s": %s
a0d0e21e
LW
1275
1276(F) The script you specified can't be opened for the indicated reason.
1277
fa3aa65a
JC
1278If you're debugging a script that uses #!, and normally relies on the
1279shell's $PATH search, the -S option causes perl to do that search, so
1280you don't have to type the path or C<`which $scriptname`>.
1281
6df41af2
GS
1282=item Can't read CRTL environ
1283
1284(S) A warning peculiar to VMS. Perl tried to read an element of %ENV
1285from the CRTL's internal environment array and discovered the array was
1286missing. You need to figure out where your CRTL misplaced its environ
be771a83
GS
1287or define F<PERL_ENV_TABLES> (see L<perlvms>) so that environ is not
1288searched.
6df41af2 1289
f3106bc8
LM
1290=item Can't redeclare "%s" in "%s"
1291
1292(F) A "my", "our" or "state" declaration was found within another declaration,
1293such as C<my ($x, my($y), $z)> or C<our (my $x)>.
1294
6df41af2
GS
1295=item Can't "redo" outside a loop block
1296
1297(F) A "redo" statement was executed to restart the current block, but
1298there isn't a current block. Note that an "if" or "else" block doesn't
1299count as a "loopish" block, as doesn't a block given to sort(), map()
1300or grep(). You can usually double the curlies to get the same effect
1301though, because the inner curlies will be considered a block that
1302loops once. See L<perlfunc/redo>.
1303
64977eb6 1304=item Can't remove %s: %s, skipping file
10f9c03d 1305
be771a83
GS
1306(S inplace) You requested an inplace edit without creating a backup
1307file. Perl was unable to remove the original file to replace it with
1308the modified file. The file was left unmodified.
10f9c03d 1309
a0d0e21e
LW
1310=item Can't rename %s to %s: %s, skipping file
1311
e476b1b5 1312(S inplace) The rename done by the B<-i> switch failed for some reason,
10f9c03d 1313probably because you don't have write permission to the directory.
a0d0e21e 1314
748a9306
LW
1315=item Can't reopen input pipe (name: %s) in binary mode
1316
be771a83
GS
1317(P) An error peculiar to VMS. Perl thought stdin was a pipe, and tried
1318to reopen it to accept binary data. Alas, it failed.
748a9306 1319
9415f659
KW
1320=item Can't represent character for Ox%X on this platform
1321
1322(F) There is a hard limit to how big a character code point can be due
1323to the fundamental properties of UTF-8, especially on EBCDIC
1324platforms. The given code point exceeds that. The only work-around is
1325to not use such a large code point.
1326
4f12ec0e
FC
1327=item Can't reset %ENV on this system
1328
1329(F) You called C<reset('E')> or similar, which tried to reset
1330all variables in the current package beginning with "E". In
1331the main package, that includes %ENV. Resetting %ENV is not
1332supported on some systems, notably VMS.
1333
fe13d51d 1334=item Can't resolve method "%s" overloading "%s" in package "%s"
6df41af2 1335
1fa582fa
FC
1336(F)(P) Error resolving overloading specified by a method name (as
1337opposed to a subroutine reference): no such method callable via the
1338package. If the method name is C<???>, this is an internal error.
6df41af2 1339
cd06dffe
GS
1340=item Can't return %s from lvalue subroutine
1341
be771a83
GS
1342(F) Perl detected an attempt to return illegal lvalues (such as
1343temporary or readonly values) from a subroutine used as an lvalue. This
1344is not allowed.
cd06dffe 1345
96ebfdd7
RK
1346=item Can't return outside a subroutine
1347
1348(F) The return statement was executed in mainline code, that is, where
1349there was no subroutine call to return out of. See L<perlsub>.
1350
78f9721b
SM
1351=item Can't return %s to lvalue scalar context
1352
6903afa2
FC
1353(F) You tried to return a complete array or hash from an lvalue
1354subroutine, but you called the subroutine in a way that made Perl
1355think you meant to return only one value. You probably meant to
1356write parentheses around the call to the subroutine, which tell
1357Perl that the call should be in list context.
78f9721b 1358
a0d0e21e
LW
1359=item Can't stat script "%s"
1360
be771a83
GS
1361(P) For some reason you can't fstat() the script even though you have it
1362open already. Bizarre.
a0d0e21e 1363
a0d0e21e
LW
1364=item Can't take log of %g
1365
fb73857a 1366(F) For ordinary real numbers, you can't take the logarithm of a
6903afa2 1367negative number or zero. There's a Math::Complex package that comes
be771a83
GS
1368standard with Perl, though, if you really want to do that for the
1369negative numbers.
a0d0e21e
LW
1370
1371=item Can't take sqrt of %g
1372
1373(F) For ordinary real numbers, you can't take the square root of a
fb73857a
PP
1374negative number. There's a Math::Complex package that comes standard
1375with Perl, though, if you really want to do that.
a0d0e21e
LW
1376
1377=item Can't undef active subroutine
1378
1379(F) You can't undefine a routine that's currently running. You can,
1380however, redefine it while it's running, and you can even undef the
1381redefined subroutine while the old routine is running. Go figure.
1382
c81225bc 1383=item Can't upgrade %s (%d) to %d
a0d0e21e 1384
be771a83
GS
1385(P) The internal sv_upgrade routine adds "members" to an SV, making it
1386into a more specialized kind of SV. The top several SV types are so
1387specialized, however, that they cannot be interconverted. This message
1388indicates that such a conversion was attempted.
a0d0e21e 1389
6651ba0b
FC
1390=item Can't use '%c' after -mname
1391
1392(F) You tried to call perl with the B<-m> switch, but you put something
1393other than "=" after the module name.
1394
1f1ec7b5
KW
1395=item Can't use a hash as a reference
1396
1397(F) You tried to use a hash as a reference, as in
66a1f5ec
FC
1398C<< %foo->{"bar"} >> or C<< %$ref->{"hello"} >>. Versions of perl
1399<= 5.22.0 used to allow this syntax, but shouldn't
1400have. This was deprecated in perl 5.6.1.
1f1ec7b5
KW
1401
1402=item Can't use an array as a reference
1403
1404(F) You tried to use an array as a reference, as in
66a1f5ec
FC
1405C<< @foo->[23] >> or C<< @$ref->[99] >>. Versions of perl <= 5.22.0
1406used to allow this syntax, but shouldn't have. This
1407was deprecated in perl 5.6.1.
1f1ec7b5 1408
1db89ea5
BS
1409=item Can't use anonymous symbol table for method lookup
1410
e27ad1f2 1411(F) The internal routine that does method lookup was handed a symbol
1db89ea5
BS
1412table that doesn't have a name. Symbol tables can become anonymous
1413for example by undefining stashes: C<undef %Some::Package::>.
1414
96ebfdd7
RK
1415=item Can't use an undefined value as %s reference
1416
1417(F) A value used as either a hard reference or a symbolic reference must
1418be a defined value. This helps to delurk some insidious errors.
1419
6df41af2
GS
1420=item Can't use bareword ("%s") as %s ref while "strict refs" in use
1421
be771a83
GS
1422(F) Only hard references are allowed by "strict refs". Symbolic
1423references are disallowed. See L<perlref>.
6df41af2 1424
90b75b61 1425=item Can't use %! because Errno.pm is not available
1d2dff63 1426
20561843 1427(F) The first time the C<%!> hash is used, perl automatically loads the
6903afa2 1428Errno.pm module. The Errno module is expected to tie the %! hash to
1d2dff63
GS
1429provide symbolic names for C<$!> errno values.
1430
1109a392
MHM
1431=item Can't use both '<' and '>' after type '%c' in %s
1432
1433(F) A type cannot be forced to have both big-endian and little-endian
1434byte-order at the same time, so this combination of modifiers is not
1435allowed. See L<perlfunc/pack>.
1436
e35475de
KW
1437=item Can't use 'defined(@array)' (Maybe you should just omit the defined()?)
1438
1439(F) defined() is not useful on arrays because it
1440checks for an undefined I<scalar> value. If you want to see if the
1441array is empty, just use C<if (@array) { # not empty }> for example.
1442
1443=item Can't use 'defined(%hash)' (Maybe you should just omit the defined()?)
1444
1445(F) C<defined()> is not usually right on hashes.
1446
1447Although C<defined %hash> is false on a plain not-yet-used hash, it
1448becomes true in several non-obvious circumstances, including iterators,
1449weak references, stash names, even remaining true after C<undef %hash>.
1450These things make C<defined %hash> fairly useless in practice, so it now
1451generates a fatal error.
1452
1453If a check for non-empty is what you wanted then just put it in boolean
1454context (see L<perldata/Scalar values>):
1455
1456 if (%hash) {
1457 # not empty
1458 }
1459
1460If you had C<defined %Foo::Bar::QUUX> to check whether such a package
1461variable exists then that's never really been reliable, and isn't
1462a good way to enquire about the features of a package, or whether
1463it's loaded, etc.
1464
6df41af2
GS
1465=item Can't use %s for loop variable
1466
c1f06047 1467(P) The parser got confused when trying to parse a C<foreach> loop.
6df41af2 1468
aab6a793 1469=item Can't use global %s in "%s"
6df41af2 1470
be771a83
GS
1471(F) You tried to declare a magical variable as a lexical variable. This
1472is not allowed, because the magic can be tied to only one location
1473(namely the global variable) and it would be incredibly confusing to
1474have variables in your program that looked like magical variables but
6df41af2
GS
1475weren't.
1476
6d3b25aa
RGS
1477=item Can't use '%c' in a group with different byte-order in %s
1478
1479(F) You attempted to force a different byte-order on a type
1480that is already inside a group with a byte-order modifier.
1481For example you cannot force little-endianness on a type that
1482is inside a big-endian group.
1483
c07a80fd
PP
1484=item Can't use "my %s" in sort comparison
1485
1486(F) The global variables $a and $b are reserved for sort comparisons.
c47ff5f1 1487You mentioned $a or $b in the same line as the <=> or cmp operator,
c07a80fd
PP
1488and the variable had earlier been declared as a lexical variable.
1489Either qualify the sort variable with the package name, or rename the
1490lexical variable.
1491
a0d0e21e
LW
1492=item Can't use %s ref as %s ref
1493
1494(F) You've mixed up your reference types. You have to dereference a
1495reference of the type needed. You can use the ref() function to
1496test the type of the reference, if need be.
1497
748a9306 1498=item Can't use string ("%s") as %s ref while "strict refs" in use
a0d0e21e 1499
5e634d20
FC
1500=item Can't use string ("%s"...) as %s ref while "strict refs" in use
1501
b41bf23f
FC
1502(F) You've told Perl to dereference a string, something which
1503C<use strict> blocks to prevent it happening accidentally. See
1504L<perlref/"Symbolic references">. This can be triggered by an C<@> or C<$>
1505in a double-quoted string immediately before interpolating a variable,
1506for example in C<"user @$twitter_id">, which says to treat the contents
1507of C<$twitter_id> as an array reference; use a C<\> to have a literal C<@>
1508symbol followed by the contents of C<$twitter_id>: C<"user \@$twitter_id">.
a0d0e21e 1509
748a9306
LW
1510=item Can't use subscript on %s
1511
1512(F) The compiler tried to interpret a bracketed expression as a
1513subscript. But to the left of the brackets was an expression that
209e7cf1 1514didn't look like a hash or array reference, or anything else subscriptable.
748a9306 1515
6df41af2
GS
1516=item Can't use \%c to mean $%c in expression
1517
75b44862
GS
1518(W syntax) In an ordinary expression, backslash is a unary operator that
1519creates a reference to its argument. The use of backslash to indicate a
1520backreference to a matched substring is valid only as part of a regular
be771a83
GS
1521expression pattern. Trying to do this in ordinary Perl code produces a
1522value that prints out looking like SCALAR(0xdecaf). Use the $1 form
1523instead.
6df41af2 1524
810b8aa5
GS
1525=item Can't weaken a nonreference
1526
1527(F) You attempted to weaken something that was not a reference. Only
1528references can be weakened.
1529
fc7debfb
FC
1530=item Can't "when" outside a topicalizer
1531
1532(F) You have used a when() block that is neither inside a C<foreach>
1533loop nor a C<given> block. (Note that this error is issued on exit
1534from the C<when> block, so you won't get the error if the match fails,
1535or if you use an explicit C<continue>.)
1536
5f05dabc 1537=item Can't x= to read-only value
a0d0e21e 1538
be771a83
GS
1539(F) You tried to repeat a constant value (often the undefined value)
1540with an assignment operator, which implies modifying the value itself.
a0d0e21e
LW
1541Perhaps you need to copy the value to a temporary, and repeat that.
1542
a04e6aad 1543=item Character following "\c" must be printable ASCII
f9d13529 1544
7357bd17 1545(F) In C<\cI<X>>, I<X> must be a printable (non-control) ASCII character.
17a3df4c 1546
727b6379 1547Note that ASCII characters that don't map to control characters are
7357bd17 1548discouraged, and will generate the warning (when enabled)
d4360efa 1549L</""\c%c" is more clearly written simply as "%s"">.
f9d13529 1550
163a633c
KW
1551=item Character following \%c must be '{' or a single-character Unicode property name in regex; marked by <-- HERE in m/%s/
1552
1553(F) (In the above the C<%c> is replaced by either C<p> or C<P>.) You
1554specified something that isn't a legal Unicode property name. Most
1555Unicode properties are specified by C<\p{...}>. But if the name is a
1556single character one, the braces may be omitted.
1557
f337b084 1558=item Character in 'C' format wrapped in pack
ac7cd81a
SC
1559
1560(W pack) You said
1561
1562 pack("C", $x)
1563
1564where $x is either less than 0 or more than 255; the C<"C"> format is
1565only for encoding native operating system characters (ASCII, EBCDIC,
1566and so on) and not for Unicode characters, so Perl behaved as if you meant
1567
1568 pack("C", $x & 255)
1569
1570If you actually want to pack Unicode codepoints, use the C<"U"> format
1571instead.
1572
f337b084 1573=item Character in 'c' format wrapped in pack
ac7cd81a
SC
1574
1575(W pack) You said
1576
1577 pack("c", $x)
1578
1579where $x is either less than -128 or more than 127; the C<"c"> format
1580is only for encoding native operating system characters (ASCII, EBCDIC,
1581and so on) and not for Unicode characters, so Perl behaved as if you meant
1582
1583 pack("c", $x & 255);
1584
1585If you actually want to pack Unicode codepoints, use the C<"U"> format
1586instead.
1587
f337b084
TH
1588=item Character in '%c' format wrapped in unpack
1589
1590(W unpack) You tried something like
1591
1592 unpack("H", "\x{2a1}")
1593
1a147d38 1594where the format expects to process a byte (a character with a value
6903afa2
FC
1595below 256), but a higher value was provided instead. Perl uses the
1596value modulus 256 instead, as if you had provided:
f337b084
TH
1597
1598 unpack("H", "\x{a1}")
1599
5a25739d
FC
1600=item Character in 'W' format wrapped in pack
1601
1602(W pack) You said
1603
1604 pack("U0W", $x)
1605
1606where $x is either less than 0 or more than 255. However, C<U0>-mode
1607expects all values to fall in the interval [0, 255], so Perl behaved
1608as if you meant:
1609
1610 pack("U0W", $x & 255)
1611
f337b084
TH
1612=item Character(s) in '%c' format wrapped in pack
1613
1614(W pack) You tried something like
1615
1616 pack("u", "\x{1f3}b")
1617
1a147d38 1618where the format expects to process a sequence of bytes (character with a
6903afa2 1619value below 256), but some of the characters had a higher value. Perl
f337b084
TH
1620uses the character values modulus 256 instead, as if you had provided:
1621
1622 pack("u", "\x{f3}b")
1623
1624=item Character(s) in '%c' format wrapped in unpack
1625
1626(W unpack) You tried something like
1627
1628 unpack("s", "\x{1f3}b")
1629
1a147d38 1630where the format expects to process a sequence of bytes (character with a
6903afa2 1631value below 256), but some of the characters had a higher value. Perl
f337b084
TH
1632uses the character values modulus 256 instead, as if you had provided:
1633
1634 unpack("s", "\x{f3}b")
1635
f51551f7
FC
1636=item charnames alias definitions may not contain a sequence of multiple spaces
1637
1638(F) You defined a character name which had multiple space characters
1639in a row. Change them to single spaces. Usually these names are
1640defined in the C<:alias> import argument to C<use charnames>, but they
1641could be defined by a translator installed into C<$^H{charnames}>. See
1642L<charnames/CUSTOM ALIASES>.
1643
1644=item charnames alias definitions may not contain trailing white-space
1645
1646(F) You defined a character name which ended in a space
1647character. Remove the trailing space(s). Usually these names are
1648defined in the C<:alias> import argument to C<use charnames>, but they
1649could be defined by a translator installed into C<$^H{charnames}>.
1650See L<charnames/CUSTOM ALIASES>.
1651
60121127
TC
1652=item chdir() on unopened filehandle %s
1653
1654(W unopened) You tried chdir() on a filehandle that was never opened.
1655
d4360efa 1656=item "\c%c" is more clearly written simply as "%s"
f866a7cd 1657
d4360efa
S
1658(W syntax) The C<\cI<X>> construct is intended to be a way to specify
1659non-printable characters. You used it for a printable one, which
1660is better written as simply itself, perhaps preceded by a backslash
1661for non-word characters. Doing it the way you did is not portable
1662between ASCII and EBCDIC platforms.
f866a7cd 1663
6651ba0b
FC
1664=item Cloning substitution context is unimplemented
1665
1666(F) Creating a new thread inside the C<s///> operator is not supported.
1667
abc7ecad
SP
1668=item closedir() attempted on invalid dirhandle %s
1669
1670(W io) The dirhandle you tried to close is either closed or not really
1671a dirhandle. Check your control flow.
1672
5a25739d
FC
1673=item close() on unopened filehandle %s
1674
1675(W unopened) You tried to close a filehandle that was never opened.
1676
541ed3a9
FC
1677=item Closure prototype called
1678
1679(F) If a closure has attributes, the subroutine passed to an attribute
1680handler is the prototype that is cloned when a new closure is created.
1681This subroutine cannot be called.
1682
74d1b2e4
FC
1683=item \C no longer supported in regex; marked by S<<-- HERE> in m/%s/
1684
1685(F) The \C character class used to allow a match of single byte
1686within a multi-byte utf-8 character, but was removed in v5.24 as
1687it broke encapsulation and its implementation was extremely buggy.
1688If you really need to process the individual bytes, you probably
1689want to convert your string to one where each underlying byte is
1690stored as a character, with utf8::encode().
1691
49704364
LW
1692=item Code missing after '/'
1693
6903afa2
FC
1694(F) You had a (sub-)template that ends with a '/'. There must be
1695another template code following the slash. See L<perlfunc/pack>.
49704364 1696
c0236afe
KW
1697=item Code point 0x%X is not Unicode, and not portable
1698
1699(S non_unicode) You had a code point that has never been in any
1700standard, so it is likely that languages other than Perl will NOT
1701understand it. At one time, it was legal in some standards to have code
1702points up to 0x7FFF_FFFF, but not higher, and this code point is higher.
1703
1704Acceptance of these code points is a Perl extension, and you should
1705expect that nothing other than Perl can handle them; Perl itself on
1706EBCDIC platforms before v5.24 does not handle them.
1707
1708Code points above 0xFFFF_FFFF require larger than a 32 bit word.
1709
1710Perl also makes no guarantees that the representation of these code
1711points won't change at some point in the future, say when machines
1712become available that have larger than a 64-bit word. At that time,
1713files written by an older Perl would require conversion before being
1714readable by a newer Perl.
1715
5a25739d
FC
1716=item Code point 0x%X is not Unicode, may not be portable
1717
2d88a86a 1718(S non_unicode) You had a code point above the Unicode maximum
1b64326b
FC
1719of U+10FFFF.
1720
c0236afe
KW
1721Perl allows strings to contain a superset of Unicode code points, but
1722these may not be accepted by other languages/systems. Further, even if
1723these languages/systems accept these large code points, they may have
1724chosen a different representation for them than the UTF-8-like one that
1725Perl has, which would mean files are not exchangeable between them and
1726Perl.
1727
1728On EBCDIC platforms, code points above 0x3FFF_FFFF have a different
1729representation in Perl v5.24 than before, so any file containing these
1730that was written before that version will require conversion before
1731being readable by a later Perl.
0876b9a0 1732
6df41af2
GS
1733=item %s: Command not found
1734
a892b81a 1735(A) You've accidentally run your script through B<csh> or another shell
66a1f5ec
FC
1736instead of Perl. Check the #! line, or manually feed your script into
1737Perl yourself. The #! line at the top of your file could look like
8f721816 1738
3bcfc7b3
LM
1739 #!/usr/bin/perl
1740
1741=item %s: command not found
1742
1743(A) You've accidentally run your script through B<bash> or another shell
1744instead of Perl. Check the #! line, or manually feed your script into
1745Perl yourself. The #! line at the top of your file could look like
1746
1747 #!/usr/bin/perl
1748
1749=item %s: command not found: %s
1750
1751(A) You've accidentally run your script through B<zsh> or another shell
1752instead of Perl. Check the #! line, or manually feed your script into
1753Perl yourself. The #! line at the top of your file could look like
1754
1755 #!/usr/bin/perl
6df41af2 1756
7a2e2cd6
PP
1757=item Compilation failed in require
1758
1759(F) Perl could not compile a file specified in a C<require> statement.
be771a83
GS
1760Perl uses this generic message when none of the errors that it
1761encountered were severe enough to halt compilation immediately.
7a2e2cd6 1762
c3464db5
DD
1763=item Complex regular subexpression recursion limit (%d) exceeded
1764
be771a83
GS
1765(W regexp) The regular expression engine uses recursion in complex
1766situations where back-tracking is required. Recursion depth is limited
1767to 32766, or perhaps less in architectures where the stack cannot grow
1768arbitrarily. ("Simple" and "medium" situations are handled without
1769recursion and are not subject to a limit.) Try shortening the string
1770under examination; looping in Perl code (e.g. with C<while>) rather than
1771in the regular expression engine; or rewriting the regular expression so
c2e66d9e 1772that it is simpler or backtracks less. (See L<perlfaq2> for information
be771a83 1773on I<Mastering Regular Expressions>.)
c3464db5 1774
69282e91 1775=item connect() on closed socket %s
a0d0e21e 1776
be771a83
GS
1777(W closed) You tried to do a connect on a closed socket. Did you forget
1778to check the return value of your socket() call? See
1779L<perlfunc/connect>.
a0d0e21e 1780
e21e7c6a
FC
1781=item Constant(%s): Call to &{$^H{%s}} did not return a defined value
1782
1783(F) The subroutine registered to handle constant overloading
1784(see L<overload>) or a custom charnames handler (see
1785L<charnames/CUSTOM TRANSLATORS>) returned an undefined value.
1786
1787=item Constant(%s): $^H{%s} is not defined
1788
1789(F) The parser found inconsistencies while attempting to define an
1790overloaded constant. Perhaps you forgot to load the corresponding
f738a371 1791L<overload> pragma?
e21e7c6a 1792
779c5bc9
GS
1793=item Constant is not %s reference
1794
1795(F) A constant value (perhaps declared using the C<use constant> pragma)
be771a83 1796is being dereferenced, but it amounts to the wrong type of reference.
6903afa2 1797The message indicates the type of reference that was expected. This
be771a83 1798usually indicates a syntax error in dereferencing the constant value.
779c5bc9
GS
1799See L<perlsub/"Constant Functions"> and L<constant>.
1800
0ac016fc 1801=item Constants from lexical variables potentially modified elsewhere are
9840d1d6 1802deprecated. This will not be allowed in Perl 5.32
0ac016fc
FC
1803
1804(D deprecated) You wrote something like
1805
1806 my $var;
1807 $sub = sub () { $var };
1808
1809but $var is referenced elsewhere and could be modified after the C<sub>
1810expression is evaluated. Either it is explicitly modified elsewhere
1811(C<$var = 3>) or it is passed to a subroutine or to an operator like
1812C<printf> or C<map>, which may or may not modify the variable.
1813
1814Traditionally, Perl has captured the value of the variable at that
1815point and turned the subroutine into a constant eligible for inlining.
1816In those cases where the variable can be modified elsewhere, this
1817breaks the behavior of closures, in which the subroutine captures
1818the variable itself, rather than its value, so future changes to the
1819variable are reflected in the subroutine's return value.
1820
9840d1d6
A
1821This usage is deprecated, and will no longer be allowed in Perl 5.32,
1822making it possible to change the behavior in the future.
0ac016fc
FC
1823
1824If you intended for the subroutine to be eligible for inlining, then
1825make sure the variable is not referenced elsewhere, possibly by
1826copying it:
1827
1828 my $var2 = $var;
1829 $sub = sub () { $var2 };
1830
1831If you do want this subroutine to be a closure that reflects future
1832changes to the variable that it closes over, add an explicit C<return>:
1833
1834 my $var;
1835 $sub = sub () { return $var };
1836
4cee8e80
CS
1837=item Constant subroutine %s redefined
1838
aeb94125
FC
1839(W redefine)(S) You redefined a subroutine which had previously
1840been eligible for inlining. See L<perlsub/"Constant Functions">
1841for commentary and workarounds.
4cee8e80 1842
9607fc9c
PP
1843=item Constant subroutine %s undefined
1844
be771a83
GS
1845(W misc) You undefined a subroutine which had previously been eligible
1846for inlining. See L<perlsub/"Constant Functions"> for commentary and
1847workarounds.
9607fc9c 1848
5a25739d
FC
1849=item Constant(%s) unknown
1850
1851(F) The parser found inconsistencies either while attempting
1852to define an overloaded constant, or when trying to find the
1853character name specified in the C<\N{...}> escape. Perhaps you
3ee1a09c 1854forgot to load the corresponding L<overload> pragma?
5a25739d 1855
4a873d7a
FC
1856=item :const is experimental
1857
1858(S experimental::const_attr) The "const" attribute is experimental.
1859If you want to use the feature, disable the warning with C<no warnings
1860'experimental::const_attr'>, but know that in doing so you are taking
1861the risk that your code may break in a future Perl version.
1862
b77472f9
FC
1863=item :const is not permitted on named subroutines
1864
1865(F) The "const" attribute causes an anonymous subroutine to be run and
465068b9 1866its value captured at the time that it is cloned. Named subroutines are
b77472f9
FC
1867not cloned like this, so the attribute does not make sense on them.
1868
e7ea3e70
IZ
1869=item Copy method did not return a reference
1870
6903afa2 1871(F) The method which overloads "=" is buggy. See
13a2d996 1872L<overload/Copy Constructor>.
e7ea3e70 1873
4aaa4757
FC
1874=item &CORE::%s cannot be called directly
1875
1876(F) You tried to call a subroutine in the C<CORE::> namespace
8d605c0d 1877with C<&foo> syntax or through a reference. Some subroutines
4aaa4757
FC
1878in this package cannot yet be called that way, but must be
1879called as barewords. Something like this will work:
1880
1881 BEGIN { *shove = \&CORE::push; }
1882 shove @array, 1,2,3; # pushes on to @array
1883
6798c92b
GS
1884=item CORE::%s is not a keyword
1885
1886(F) The CORE:: namespace is reserved for Perl keywords.
1887
675fa9ff
FC
1888=item Corrupted regexp opcode %d > %d
1889
1890(P) This is either an error in Perl, or, if you're using
1891one, your L<custom regular expression engine|perlreapi>. If not the
1892latter, report the problem through the L<perlbug> utility.
1893
a0d0e21e
LW
1894=item corrupted regexp pointers
1895
1896(P) The regular expression engine got confused by what the regular
1897expression compiler gave it.
1898
1899=item corrupted regexp program
1900
be771a83
GS
1901(P) The regular expression engine got passed a regexp program without a
1902valid magic number.
a0d0e21e 1903
de42a5a9 1904=item Corrupt malloc ptr 0x%x at 0x%x
6df41af2
GS
1905
1906(P) The malloc package that comes with Perl had an internal failure.
1907
49704364
LW
1908=item Count after length/code in unpack
1909
1910(F) You had an unpack template indicating a counted-length string, but
1911you have also specified an explicit size for the string. See
1912L<perlfunc/pack>.
1913
3f645a4e
FC
1914=item Declaring references is experimental
1915
1916(S experimental::declared_refs) This warning is emitted if you use
1917a reference constructor on the right-hand side of C<my>, C<state>, C<our>, or
1918C<local>. Simply suppress the warning if you want to use the feature, but
1919know that in doing so you are taking the risk of using an experimental
1920feature which may change or be removed in a future Perl version:
1921
1922 no warnings "experimental::declared_refs";
1923 use feature "declared_refs";
1924 $fooref = my \$foo;
1925
f2cccb4c
KW
1926=for comment
1927The following are used in lib/diagnostics.t for testing two =items that
1928share the same description. Changes here need to be propagated to there
1929
6651ba0b
FC
1930=item Deep recursion on anonymous subroutine
1931
a0d0e21e
LW
1932=item Deep recursion on subroutine "%s"
1933
be771a83
GS
1934(W recursion) This subroutine has called itself (directly or indirectly)
1935100 times more than it has returned. This probably indicates an
1936infinite recursion, unless you're writing strange benchmark programs, in
1937which case it indicates something else.
a0d0e21e 1938
aad1d01f
NC
1939This threshold can be changed from 100, by recompiling the F<perl> binary,
1940setting the C pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value.
1941
e0e4a6e3
FC
1942=item (?(DEFINE)....) does not allow branches in regex; marked by
1943S<<-- HERE> in m/%s/
bcb95744 1944
6903afa2 1945(F) You used something like C<(?(DEFINE)...|..)> which is illegal. The
bcb95744
FC
1946most likely cause of this error is that you left out a parenthesis inside
1947of the C<....> part.
1948
6e8a73f2 1949The S<<-- HERE> shows whereabouts in the regular expression the problem was
bcb95744
FC
1950discovered.
1951
62658f4d
PM
1952=item %s defines neither package nor VERSION--version check failed
1953
1954(F) You said something like "use Module 42" but in the Module file
1955there are neither package declarations nor a C<$VERSION>.
1956
36447869
FC
1957=item delete argument is index/value array slice, use array slice
1958
1959(F) You used index/value array slice syntax (C<%array[...]>) as
1960the argument to C<delete>. You probably meant C<@array[...]> with
1961an @ symbol instead.
1962
1963=item delete argument is key/value hash slice, use hash slice
1964
1965(F) You used key/value hash slice syntax (C<%hash{...}>) as the argument to
1966C<delete>. You probably meant C<@hash{...}> with an @ symbol instead.
1967
0ffcbc25
FC
1968=item delete argument is not a HASH or ARRAY element or slice
1969
4a0af295 1970(F) The argument to C<delete> must be either a hash or array element,
0ffcbc25
FC
1971such as:
1972
1973 $foo{$bar}
1974 $ref->{"susie"}[12]
1975
1976or a hash or array slice, such as:
1977
1978 @foo[$bar, $baz, $xyzzy]
1979 @{$ref->[12]}{"susie", "queue"}
1980
fc36a67e
PP
1981=item Delimiter for here document is too long
1982
be771a83
GS
1983(F) In a here document construct like C<<<FOO>, the label C<FOO> is too
1984long for Perl to handle. You have to be seriously twisted to write code
1985that triggers this error.
fc36a67e 1986
c437f7ac 1987=item Deprecated use of my() in false conditional. This will be a fatal error in Perl 5.30
6d3b25aa 1988
fa816bf3
FC
1989(D deprecated) You used a declaration similar to C<my $x if 0>. There
1990has been a long-standing bug in Perl that causes a lexical variable
6d3b25aa 1991not to be cleared at scope exit when its declaration includes a false
6903afa2 1992conditional. Some people have exploited this bug to achieve a kind of
fa816bf3 1993static variable. Since we intend to fix this bug, we don't want people
6903afa2 1994relying on this behavior. You can achieve a similar static effect by
6d3b25aa 1995declaring the variable in a separate block outside the function, eg
36fb85f3 1996
6d3b25aa
RGS
1997 sub f { my $x if 0; return $x++ }
1998
1999becomes
2000
2001 { my $x; sub f { return $x++ } }
2002
ea9d9ebc 2003Beginning with perl 5.10.0, you can also use C<state> variables to have
fa816bf3 2004lexicals that are initialized only once (see L<feature>):
36fb85f3
RGS
2005
2006 sub f { state $x; return $x++ }
2007
c437f7ac
A
2008This use of C<my()> in a false conditional has been deprecated since
2009Perl 5.10, and it will become a fatal error in Perl 5.30.
2010
500ab966
RGS
2011=item DESTROY created new reference to dead object '%s'
2012
2013(F) A DESTROY() method created a new reference to the object which is
6903afa2
FC
2014just being DESTROYed. Perl is confused, and prefers to abort rather
2015than to create a dangling reference.
500ab966 2016
3cdd684c
TP
2017=item Did not produce a valid header
2018
3de20fbe 2019See L</500 Server error>.
3cdd684c 2020
6df41af2
GS
2021=item %s did not return a true value
2022
2023(F) A required (or used) file must return a true value to indicate that
2024it compiled correctly and ran its initialization code correctly. It's
2025traditional to end such a file with a "1;", though any true value would
2026do. See L<perlfunc/require>.
2027
cc507455 2028=item (Did you mean &%s instead?)
4633a7c4 2029
413ff9f6
FC
2030(W misc) You probably referred to an imported subroutine &FOO as $FOO or
2031some such.
4633a7c4 2032
cc507455 2033=item (Did you mean "local" instead of "our"?)
33633739 2034
be771a83
GS
2035(W misc) Remember that "our" does not localize the declared global
2036variable. You have declared it again in the same lexical scope, which
2037seems superfluous.
33633739 2038
cc507455 2039=item (Did you mean $ or @ instead of %?)
a0d0e21e 2040
be771a83
GS
2041(W) You probably said %hash{$key} when you meant $hash{$key} or
2042@hash{@keys}. On the other hand, maybe you just meant %hash and got
2043carried away.
748a9306 2044
7e1af8bc 2045=item Died
5f05dabc
PP
2046
2047(F) You passed die() an empty string (the equivalent of C<die "">) or
075b00aa 2048you called it with no args and C<$@> was empty.
5f05dabc 2049
3cdd684c
TP
2050=item Document contains no data
2051
3de20fbe 2052See L</500 Server error>.
3cdd684c 2053
62658f4d
PM
2054=item %s does not define %s::VERSION--version check failed
2055
2056(F) You said something like "use Module 42" but the Module did not
943fc58e 2057define a C<$VERSION>.
62658f4d 2058
49704364
LW
2059=item '/' does not take a repeat count
2060
2061(F) You cannot put a repeat count of any kind right after the '/' code.
2062See L<perlfunc/pack>.
2063
1c99110e 2064=item do "%s" failed, '.' is no longer in @INC; did you mean do "./%s"?
2a0461a3
TC
2065
2066(W deprecated) Previously C< do "somefile"; > would search the current
1c99110e
DM
2067directory for the specified file. Since perl v5.26.0, F<.> has been
2068removed from C<@INC> by default, so this is no longer true. To search the
2069current directory (and only the current directory) you can write
2070C< do "./somefile"; >.
2a0461a3 2071
95cb0d72
FC
2072=item Don't know how to get file name
2073
2074(P) C<PerlIO_getname>, a perl internal I/O function specific to VMS, was
2075somehow called on another platform. This should not happen.
2076
4021c788 2077=item Don't know how to handle magic of type \%o
a0d0e21e
LW
2078
2079(P) The internal handling of magical variables has been cursed.
2080
2081=item do_study: out of memory
2082
2083(P) This should have been caught by safemalloc() instead.
2084
6df41af2
GS
2085=item (Do you need to predeclare %s?)
2086
56da5a46
RGS
2087(S syntax) This is an educated guess made in conjunction with the message
2088"%s found where operator expected". It often means a subroutine or module
6df41af2
GS
2089name is being referenced that hasn't been declared yet. This may be
2090because of ordering problems in your file, or because of a missing
be771a83
GS
2091"sub", "package", "require", or "use" statement. If you're referencing
2092something that isn't defined yet, you don't actually have to define the
2093subroutine or package before the current location. You can use an empty
2094"sub foo;" or "package FOO;" to enter a "forward" declaration.
6df41af2 2095
30b17cc1 2096=item dump() better written as CORE::dump(). dump() will no longer be available in Perl 5.30
ac206dc8 2097
30b17cc1
A
2098(D deprecated, misc) You used the obsolescent C<dump()> built-in function,
2099without fully qualifying it as C<CORE::dump()>. Maybe it's a typo.
2100
4fa40147 2101Use of a unqualified C<dump()> was deprecated in Perl 5.8.0, and this
30b17cc1
A
2102will not be available in Perl 5.30.
2103
2104See L<perlfunc/dump>.
ac206dc8 2105
84d78eb7
YO
2106=item dump is not supported
2107
2108(F) Your machine doesn't support dump/undump.
2109
a0d0e21e
LW
2110=item Duplicate free() ignored
2111
be771a83
GS
2112(S malloc) An internal routine called free() on something that had
2113already been freed.
a0d0e21e 2114
1109a392
MHM
2115=item Duplicate modifier '%c' after '%c' in %s
2116
35f0cd76
FC
2117(W unpack) You have applied the same modifier more than once after a
2118type in a pack template. See L<perlfunc/pack>.
1109a392 2119
4633a7c4
LW
2120=item elseif should be elsif
2121
fa816bf3
FC
2122(S syntax) There is no keyword "elseif" in Perl because Larry thinks
2123it's ugly. Your code will be interpreted as an attempt to call a method
2124named "elseif" for the class returned by the following block. This is
4633a7c4
LW
2125unlikely to be what you want.
2126
c30c479a
KW
2127=item Empty \%c in regex; marked by S<<-- HERE> in m/%s/
2128
e0e4a6e3 2129=item Empty \%c{} in regex; marked by S<<-- HERE> in m/%s/
ab13f0c7 2130
af6f566e 2131(F) C<\p> and C<\P> are used to introduce a named Unicode property, as
6903afa2 2132described in L<perlunicode> and L<perlre>. You used C<\p> or C<\P> in
af6f566e 2133a regular expression without specifying the property name.
ab13f0c7 2134
ac641426 2135=item ${^ENCODING} is no longer supported. Its use will be fatal in Perl 5.28
a15a3d9b
FC
2136
2137(D deprecated) The special variable C<${^ENCODING}>, formerly used to implement
2138the C<encoding> pragma, is no longer supported as of Perl 5.26.0.
2139
ac641426
A
2140Setting this variable will become a fatal error in Perl 5.28.
2141
85ab1d1d 2142=item entering effective %s failed
5ff3f7a4 2143
85ab1d1d 2144(F) While under the C<use filetest> pragma, switching the real and
5ff3f7a4
GS
2145effective uids or gids failed.
2146
c038024b
RGS
2147=item %ENV is aliased to %s
2148
2149(F) You're running under taint mode, and the C<%ENV> variable has been
2150aliased to another hash, so it doesn't reflect anymore the state of the
6903afa2 2151program's environment. This is potentially insecure.
c038024b 2152
748a9306
LW
2153=item Error converting file specification %s
2154
5f05dabc 2155(F) An error peculiar to VMS. Because Perl may have to deal with file
748a9306 2156specifications in either VMS or Unix syntax, it converts them to a
be771a83
GS
2157single form when it must operate on them directly. Either you've passed
2158an invalid file specification to Perl, or you've found a case the
2159conversion routines don't handle. Drat.
748a9306 2160
ad19ef22 2161=item Eval-group in insecure regular expression
e4d48cc9 2162
be771a83
GS
2163(F) Perl detected tainted data when trying to compile a regular
2164expression that contains the C<(?{ ... })> zero-width assertion, which
2165is unsafe. See L<perlre/(?{ code })>, and L<perlsec>.
e4d48cc9 2166
ad19ef22 2167=item Eval-group not allowed at runtime, use re 'eval' in regex m/%s/
e4d48cc9 2168
be771a83
GS
2169(F) Perl tried to compile a regular expression containing the
2170C<(?{ ... })> zero-width assertion at run time, as it would when the
f11307f5
FC
2171pattern contains interpolated values. Since that is a security risk,
2172it is not allowed. If you insist, you may still do this by using the
2173C<re 'eval'> pragma or by explicitly building the pattern from an
2174interpolated string at run time and using that in an eval(). See
2175L<perlre/(?{ code })>.
e4d48cc9 2176
ad19ef22 2177=item Eval-group not allowed, use re 'eval' in regex m/%s/
6df41af2 2178
be771a83
GS
2179(F) A regular expression contained the C<(?{ ... })> zero-width
2180assertion, but that construct is only allowed when the C<use re 'eval'>
2181pragma is in effect. See L<perlre/(?{ code })>.
6df41af2 2182
e0e4a6e3
FC
2183=item EVAL without pos change exceeded limit in regex; marked by
2184S<<-- HERE> in m/%s/
1a147d38
YO
2185
2186(F) You used a pattern that nested too many EVAL calls without consuming
6903afa2 2187any text. Restructure the pattern so that text is consumed.
1a147d38 2188
6e8a73f2 2189The S<<-- HERE> shows whereabouts in the regular expression the problem was
1a147d38
YO
2190discovered.
2191
fc36a67e
PP
2192=item Excessively long <> operator
2193
2194(F) The contents of a <> operator may not exceed the maximum size of a
2195Perl identifier. If you're just trying to glob a long list of
2196filenames, try using the glob() operator, or put the filenames into a
2197variable and glob that.
2198
ed9aa3b7
SG
2199=item exec? I'm not *that* kind of operating system
2200
af8bb25a 2201(F) The C<exec> function is not implemented on some systems, e.g., Symbian
6903afa2 2202OS. See L<perlport>.
ed9aa3b7 2203
c77da5ff 2204=item %sExecution of %s aborted due to compilation errors.
a0d0e21e
LW
2205
2206(F) The final summary message when a Perl compilation fails.
2207
0ffcbc25
FC
2208=item exists argument is not a HASH or ARRAY element or a subroutine
2209
4a0af295 2210(F) The argument to C<exists> must be a hash or array element or a
0ffcbc25
FC
2211subroutine with an ampersand, such as:
2212
2213 $foo{$bar}
2214 $ref->{"susie"}[12]
2215 &do_something
2216
2217=item exists argument is not a subroutine name
2218
ccfc2567
FC
2219(F) The argument to C<exists> for C<exists &sub> must be a subroutine name,
2220and not a subroutine call. C<exists &sub()> will generate this error.
0ffcbc25 2221
a0d0e21e
LW
2222=item Exiting eval via %s
2223
be771a83
GS
2224(W exiting) You are exiting an eval by unconventional means, such as a
2225goto, or a loop control statement.
e476b1b5
GS
2226
2227=item Exiting format via %s
2228
9a2ff54b 2229(W exiting) You are exiting a format by unconventional means, such as a
be771a83 2230goto, or a loop control statement.
a0d0e21e 2231
0a753a76
PP
2232=item Exiting pseudo-block via %s
2233
be771a83
GS
2234(W exiting) You are exiting a rather special block construct (like a
2235sort block or subroutine) by unconventional means, such as a goto, or a
2236loop control statement. See L<perlfunc/sort>.
0a753a76 2237
a0d0e21e
LW
2238=item Exiting subroutine via %s
2239
be771a83
GS
2240(W exiting) You are exiting a subroutine by unconventional means, such
2241as a goto, or a loop control statement.
a0d0e21e
LW
2242
2243=item Exiting substitution via %s
2244
be771a83
GS
2245(W exiting) You are exiting a substitution by unconventional means, such
2246as a return, a goto, or a loop control statement.
a0d0e21e 2247
e0e4a6e3 2248=item Expecting close bracket in regex; marked by S<<-- HERE> in m/%s/
c608e803 2249
675fa9ff 2250(F) You wrote something like
c608e803
KW
2251
2252 (?13
2253
2254to denote a capturing group of the form
2255L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>,
2256but omitted the C<")">.
2257
e0e4a6e3 2258=item Expecting '(?flags:(?[...' in regex; marked by S<<-- HERE> in m/%s/
27350048 2259
8b6fbf55
FC
2260(F) The C<(?[...])> extended character class regular expression construct
2261only allows character classes (including character class escapes like
2262C<\d>), operators, and parentheses. The one exception is C<(?flags:...)>
2263containing at least one flag and exactly one C<(?[...])> construct.
27350048
FC
2264This allows a regular expression containing just C<(?[...])> to be
2265interpolated. If you see this error message, then you probably
2266have some other C<(?...)> construct inside your character class. See
2267L<perlrecharclass/Extended Bracketed Character Classes>.
2268
baabe3fb 2269=item Experimental aliasing via reference not enabled
1f8155a2 2270
baabe3fb 2271(F) To do aliasing via references, you must first enable the feature:
1f8155a2 2272
baabe3fb
FC
2273 no warnings "experimental::refaliasing";
2274 use feature "refaliasing";
1f8155a2
FC
2275 \$x = \$y;
2276
74d1b2e4
FC
2277=item Experimental %s on scalar is now forbidden
2278
2279(F) An experimental feature added in Perl 5.14 allowed C<each>, C<keys>,
2280C<push>, C<pop>, C<shift>, C<splice>, C<unshift>, and C<values> to be called with a
2281scalar argument. This experiment is considered unsuccessful, and
2282has been removed. The C<postderef> feature may meet your needs better.
2283
30d9c59b
Z
2284=item Experimental subroutine signatures not enabled
2285
2286(F) To use subroutine signatures, you must first enable them:
2287
caa35032 2288 no warnings "experimental::signatures";
30d9c59b
Z
2289 use feature "signatures";
2290 sub foo ($left, $right) { ... }
2291
7b8d334a
GS
2292=item Explicit blessing to '' (assuming package main)
2293
be771a83
GS
2294(W misc) You are blessing a reference to a zero length string. This has
2295the effect of blessing the reference into the package main. This is
2296usually not what you want. Consider providing a default target package,
2297e.g. bless($ref, $p || 'MyPackage');
7b8d334a 2298
6df41af2
GS
2299=item %s: Expression syntax
2300
be771a83
GS
2301(A) You've accidentally run your script through B<csh> instead of Perl.
2302Check the #! line, or manually feed your script into Perl yourself.
6df41af2
GS
2303
2304=item %s failed--call queue aborted
2305
3c10abe3
AG
2306(F) An untrapped exception was raised while executing a UNITCHECK,
2307CHECK, INIT, or END subroutine. Processing of the remainder of the
2308queue of such routines has been prematurely ended.
6df41af2 2309
502aca56
TC
2310=item Failed to close in-place edit file %s: %s
2311
2312(F) Closing an output file from in-place editing, as with the C<-i>
2313command-line switch, failed.
2314
e0e4a6e3 2315=item False [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
73b437c8 2316
98d31c73 2317(W regexp)(F) A character class range must start and end at a literal
7253e4e3 2318character, not another character class like C<\d> or C<[:alpha:]>. The "-"
3c6ca74a
FC
2319in your false range is interpreted as a literal "-". In a C<(?[...])>
2320construct, this is an error, rather than a warning. Consider quoting
e0e4a6e3 2321the "-", "\-". The S<<-- HERE> shows whereabouts in the regular expression
3c6ca74a 2322the problem was discovered. See L<perlre>.
73b437c8 2323
1b1ee2ef 2324=item Fatal VMS error (status=%d) at %s, line %d
a0d0e21e 2325
be771a83
GS
2326(P) An error peculiar to VMS. Something untoward happened in a VMS
2327system service or RTL routine; Perl's exit status should provide more
2328details. The filename in "at %s" and the line number in "line %d" tell
2329you which section of the Perl source code is distressed.
a0d0e21e
LW
2330
2331=item fcntl is not implemented
2332
2333(F) Your machine apparently doesn't implement fcntl(). What is this, a
2334PDP-11 or something?
2335
22846ab4
AB
2336=item FETCHSIZE returned a negative value
2337
2338(F) A tied array claimed to have a negative number of elements, which
2339is not possible.
2340
f337b084
TH
2341=item Field too wide in 'u' format in pack
2342
d8b5cc61 2343(W pack) Each line in an uuencoded string starts with a length indicator
6903afa2
FC
2344which can't encode values above 63. So there is no point in asking for
2345a line length bigger than that. Perl will behave as if you specified
5c96f6f7 2346C<u63> as the format.
f337b084 2347
a0e213fc
A
2348=item File::Glob::glob() will disappear in perl 5.30. Use File::Glob::bsd_glob() instead.
2349
2350(D deprecated) C<< File::Glob >> has a function called C<< glob >>, which
2351just calls C<< bsd_glob >>. However, its prototype is different from the
2352prototype of C<< CORE::glob >>, and hence, C<< File::Glob::glob >> should
2353not be used.
2354
2355C<< File::Glob::glob() >> was deprecated in perl 5.8.0. A deprecation
2356message was issued from perl 5.26.0 onwards, and the function will
2357disappear in perl 5.30.0.
2358
2359Code using C<< File::Glob::glob() >> should call
2360C<< File::Glob::bsd_glob() >> instead.
2361
af8c498a 2362=item Filehandle %s opened only for input
a0d0e21e 2363
6c8d78fb
HS
2364(W io) You tried to write on a read-only filehandle. If you intended
2365it to be a read-write filehandle, you needed to open it with "+<" or
2366"+>" or "+>>" instead of with "<" or nothing. If you intended only to
2367write the file, use ">" or ">>". See L<perlfunc/open>.
a0d0e21e 2368
af8c498a 2369=item Filehandle %s opened only for output
a0d0e21e 2370
6c8d78fb
HS
2371(W io) You tried to read from a filehandle opened only for writing, If
2372you intended it to be a read/write filehandle, you needed to open it
89a1bda8
FC
2373with "+<" or "+>" or "+>>" instead of with ">". If you intended only to
2374read from the file, use "<". See L<perlfunc/open>. Another possibility
2375is that you attempted to open filedescriptor 0 (also known as STDIN) for
2376output (maybe you closed STDIN earlier?).
97828cef
RGS
2377
2378=item Filehandle %s reopened as %s only for input
2379
2380(W io) You opened for reading a filehandle that got the same filehandle id
6903afa2 2381as STDOUT or STDERR. This occurred because you closed STDOUT or STDERR
97828cef
RGS
2382previously.
2383
2384=item Filehandle STDIN reopened as %s only for output
2385
2386(W io) You opened for writing a filehandle that got the same filehandle id
fa816bf3 2387as STDIN. This occurred because you closed STDIN previously.
a0d0e21e
LW
2388
2389=item Final $ should be \$ or $name
2390
2391(F) You must now decide whether the final $ in a string was meant to be
be771a83
GS
2392a literal dollar sign, or was meant to introduce a variable name that
2393happens to be missing. So you have to put either the backslash or the
2394name.
a0d0e21e 2395
56e90b21
GS
2396=item flock() on closed filehandle %s
2397
be771a83 2398(W closed) The filehandle you're attempting to flock() got itself closed
c289d2f7 2399some time before now. Check your control flow. flock() operates on
be771a83
GS
2400filehandles. Are you attempting to call flock() on a dirhandle by the
2401same name?
56e90b21 2402
6df41af2
GS
2403=item Format not terminated
2404
2405(F) A format must be terminated by a line with a solitary dot. Perl got
2406to the end of your file without finding such a line.
2407
a0d0e21e
LW
2408=item Format %s redefined
2409
e476b1b5 2410(W redefine) You redefined a format. To suppress this warning, say
a0d0e21e
LW
2411
2412 {
271595cc 2413 no warnings 'redefine';
a0d0e21e
LW
2414 eval "format NAME =...";
2415 }
2416
a0d0e21e
LW
2417=item Found = in conditional, should be ==
2418
e476b1b5 2419(W syntax) You said
a0d0e21e
LW
2420
2421 if ($foo = 123)
2422
2423when you meant
2424
2425 if ($foo == 123)
2426
2427(or something like that).
2428
6df41af2
GS
2429=item %s found where operator expected
2430
56da5a46
RGS
2431(S syntax) The Perl lexer knows whether to expect a term or an operator.
2432If it sees what it knows to be a term when it was expecting to see an
be771a83
GS
2433operator, it gives you this warning. Usually it indicates that an
2434operator or delimiter was omitted, such as a semicolon.
6df41af2 2435
a0d0e21e
LW
2436=item gdbm store returned %d, errno %d, key "%s"
2437
2438(S) A warning from the GDBM_File extension that a store failed.
2439
2440=item gethostent not implemented
2441
2442(F) Your C library apparently doesn't implement gethostent(), probably
2443because if it did, it'd feel morally obligated to return every hostname
2444on the Internet.
2445
69282e91 2446=item get%sname() on closed socket %s
a0d0e21e 2447
be771a83
GS
2448(W closed) You tried to get a socket or peer socket name on a closed
2449socket. Did you forget to check the return value of your socket() call?
a0d0e21e 2450
748a9306
LW
2451=item getpwnam returned invalid UIC %#o for user "%s"
2452
2453(S) A warning peculiar to VMS. The call to C<sys$getuai> underlying the
2454C<getpwnam> operator returned an invalid UIC.
2455
6df41af2
GS
2456=item getsockopt() on closed socket %s
2457
be771a83
GS
2458(W closed) You tried to get a socket option on a closed socket. Did you
2459forget to check the return value of your socket() call? See
6df41af2
GS
2460L<perlfunc/getsockopt>.
2461
0f539b13
BF
2462=item given is experimental
2463
675fa9ff
FC
2464(S experimental::smartmatch) C<given> depends on smartmatch, which
2465is experimental, so its behavior may change or even be removed
2466in any future release of perl. See the explanation under
2467L<perlsyn/Experimental Details on given and when>.
0f539b13 2468
68567d27
FC
2469=item Global symbol "%s" requires explicit package name (did you forget to
2470declare "my %s"?)
6df41af2 2471
a4edf47d 2472(F) You've said "use strict" or "use strict vars", which indicates
30c282f6 2473that all variables must either be lexically scoped (using "my" or "state"),
a4edf47d
GS
2474declared beforehand using "our", or explicitly qualified to say
2475which package the global variable is in (using "::").
6df41af2 2476
e476b1b5
GS
2477=item glob failed (%s)
2478
5ead438e 2479(S glob) Something went wrong with the external program(s) used
73c4e9dc
FC
2480for C<glob> and C<< <*.c> >>. Usually, this means that you supplied a C<glob>
2481pattern that caused the external program to fail and exit with a
be771a83 2482nonzero status. If the message indicates that the abnormal exit
73c4e9dc
FC
2483resulted in a coredump, this may also mean that your csh (C shell)
2484is broken. If so, you should change all of the csh-related variables
2485in config.sh: If you have tcsh, make the variables refer to it as
2486if it were csh (e.g. C<full_csh='/usr/bin/tcsh'>); otherwise, make them
2487all empty (except that C<d_csh> should be C<'undef'>) so that Perl will
be771a83 2488think csh is missing. In either case, after editing config.sh, run
75b44862 2489C<./Configure -S> and rebuild Perl.
e476b1b5 2490
a0d0e21e
LW
2491=item Glob not terminated
2492
2493(F) The lexer saw a left angle bracket in a place where it was expecting
be771a83
GS
2494a term, so it's looking for the corresponding right angle bracket, and
2495not finding it. Chances are you left some needed parentheses out
2496earlier in the line, and you really meant a "less than".
a0d0e21e 2497
b35b96b6
JH
2498=item gmtime(%f) failed
2499
2500(W overflow) You called C<gmtime> with a number that it could not handle:
2501too large, too small, or NaN. The returned value is C<undef>.
2502
bcd05b94 2503=item gmtime(%f) too large
8b56d6ff 2504
e9200be3 2505(W overflow) You called C<gmtime> with a number that was larger than
fc003d4b 2506it can reliably handle and C<gmtime> probably returned the wrong
6903afa2 2507date. This warning is also triggered with NaN (the special
fc003d4b
MS
2508not-a-number value).
2509
bcd05b94 2510=item gmtime(%f) too small
fc003d4b 2511
e9200be3 2512(W overflow) You called C<gmtime> with a number that was smaller than
e7a1a147 2513it can reliably handle and C<gmtime> probably returned the wrong date.
8b56d6ff 2514
6df41af2 2515=item Got an error from DosAllocMem
a0d0e21e 2516
6df41af2
GS
2517(P) An error peculiar to OS/2. Most probably you're using an obsolete
2518version of Perl, and this should not happen anyway.
a0d0e21e
LW
2519
2520=item goto must have label
2521
2522(F) Unlike with "next" or "last", you're not allowed to goto an
2523unspecified destination. See L<perlfunc/goto>.
2524
6651ba0b
FC
2525=item Goto undefined subroutine%s
2526
2527(F) You tried to call a subroutine with C<goto &sub> syntax, but
2528the indicated subroutine hasn't been defined, or if it was, it
2529has since been undefined.
2530
6fbc9859 2531=item Group name must start with a non-digit word character in regex; marked by
e0e4a6e3 2532S<<-- HERE> in m/%s/
1f4f6bf1
YO
2533
2534(F) Group names must follow the rules for perl identifiers, meaning
f26c79ba
FC
2535they must start with a non-digit word character. A common cause of
2536this error is using (?&0) instead of (?0). See L<perlre>.
1f4f6bf1 2537
5a25739d
FC
2538=item ()-group starts with a count
2539
2540(F) A ()-group started with a count. A count is supposed to follow
2541something: a template character or a ()-group. See L<perlfunc/pack>.
2542
fe13d51d 2543=item %s had compilation errors.
6df41af2
GS
2544
2545(F) The final summary message when a C<perl -c> fails.
2546
a0d0e21e
LW
2547=item Had to create %s unexpectedly
2548
be771a83
GS
2549(S internal) A routine asked for a symbol from a symbol table that ought
2550to have existed already, but for some reason it didn't, and had to be
2551created on an emergency basis to prevent a core dump.
a0d0e21e 2552
6df41af2
GS
2553=item %s has too many errors
2554
2555(F) The parser has given up trying to parse the program after 10 errors.
2556Further error messages would likely be uninformative.
2557
61e61fbc
JH
2558=item Hexadecimal float: exponent overflow
2559
d8f2b442 2560(W overflow) The hexadecimal floating point has a larger exponent
61e61fbc
JH
2561than the floating point supports.
2562
2563=item Hexadecimal float: exponent underflow
2564
d8f2b442 2565(W overflow) The hexadecimal floating point has a smaller exponent
b6d9b423
JH
2566than the floating point supports. With the IEEE 754 floating point,
2567this may also mean that the subnormals (formerly known as denormals)
2568are being used, which may or may not be an error.
61e61fbc 2569
5488d373 2570=item Hexadecimal float: internal error (%s)
cf4f6003
JH
2571
2572(F) Something went horribly bad in hexadecimal float handling.
2573
61e61fbc
JH
2574=item Hexadecimal float: mantissa overflow
2575
2576(W overflow) The hexadecimal floating point literal had more bits in
2577the mantissa (the part between the 0x and the exponent, also known as
2578the fraction or the significand) than the floating point supports.
2579
40bca5ae
JH
2580=item Hexadecimal float: precision loss
2581
2582(W overflow) The hexadecimal floating point had internally more
2583digits than could be output. This can be caused by unsupported
2584long double formats, or by 64-bit integers not being available
2585(needed to retrieve the digits under some configurations).
2586
2587=item Hexadecimal float: unsupported long double format
2588
2589(F) You have configured Perl to use long doubles but
d8f2b442 2590the internals of the long double format are unknown;
40bca5ae
JH
2591therefore the hexadecimal float output is impossible.
2592
252aa082
JH
2593=item Hexadecimal number > 0xffffffff non-portable
2594
e476b1b5 2595(W portable) The hexadecimal number you specified is larger than 2**32-1
9e24b6e2
JH
2596(4294967295) and therefore non-portable between systems. See
2597L<perlport> for more on portability concerns.
252aa082 2598
8903cb82
PP
2599=item Identifier too long
2600
2601(F) Perl limits identifiers (names for variables, functions, etc.) to
fc36a67e 2602about 250 characters for simple names, and somewhat more for compound
be771a83
GS
2603names (like C<$A::B>). You've exceeded Perl's limits. Future versions
2604of Perl are likely to eliminate these arbitrary limitations.
8903cb82 2605
e0e4a6e3
FC
2606=item Ignoring zero length \N{} in character class in regex; marked by
2607S<<-- HERE> in m/%s/
fc8cd66c 2608
f3ba6905 2609(W regexp) Named Unicode character escapes (C<\N{...}>) may return a
0f44b2a5
FC
2610zero-length sequence. When such an escape is used in a character
2611class its behavior is not well defined. Check that the correct
2612escape has been used, and the correct charname handler is in scope.
fc8cd66c 2613
6df41af2 2614=item Illegal binary digit %s
f675dbe5 2615
6df41af2 2616(F) You used a digit other than 0 or 1 in a binary number.
f675dbe5 2617
6df41af2 2618=item Illegal binary digit %s ignored
a0d0e21e 2619
be771a83
GS
2620(W digit) You may have tried to use a digit other than 0 or 1 in a
2621binary number. Interpretation of the binary number stopped before the
2622offending digit.
a0d0e21e 2623
6597eb22
FC
2624=item Illegal character after '_' in prototype for %s : %s
2625
e4d150f1
FC
2626(W illegalproto) An illegal character was found in a prototype
2627declaration. The '_' in a prototype must be followed by a ';',
2628indicating the rest of the parameters are optional, or one of '@'
2629or '%', since those two will accept 0 or more final parameters.
6597eb22 2630
b913d0b8
FC
2631=item Illegal character \%o (carriage return)
2632
2633(F) Perl normally treats carriage returns in the program text as
2634it would any other whitespace, which means you should never see
2635this error when Perl was built using standard options. For some
2636reason, your version of Perl appears to have been built without
2637this support. Talk to your Perl administrator.
2638
bb6b75cd 2639=item Illegal character following sigil in a subroutine signature
d3d9da4a
DM
2640
2641(F) A parameter in a subroutine signature contained an unexpected character
d4e5761f
FC
2642following the C<$>, C<@> or C<%> sigil character. Normally the sigil
2643should be followed by the variable name or C<=> etc. Perhaps you are
d3d9da4a
DM
2644trying use a prototype while in the scope of C<use feature 'signatures'>?
2645For example:
2646
2647 sub foo ($$) {} # legal - a prototype
2648
2649 use feature 'signatures;
2650 sub foo ($$) {} # illegal - was expecting a signature
2651 sub foo ($a, $b)
2652 :prototype($$) {} # legal
2653
2654
d37a9538
ST
2655=item Illegal character in prototype for %s : %s
2656
197afce1 2657(W illegalproto) An illegal character was found in a prototype declaration.
2e9cc7ef 2658Legal characters in prototypes are $, @, %, *, ;, [, ], &, \, and +.
30d9c59b
Z
2659Perhaps you were trying to write a subroutine signature but didn't enable
2660that feature first (C<use feature 'signatures'>), so your signature was
2661instead interpreted as a bad prototype.
d37a9538 2662
904d85c5
RGS
2663=item Illegal declaration of anonymous subroutine
2664
2665(F) When using the C<sub> keyword to construct an anonymous subroutine,
6903afa2 2666you must always specify a block of code. See L<perlsub>.
904d85c5 2667
8e742a20
MHM
2668=item Illegal declaration of subroutine %s
2669
6903afa2 2670(F) A subroutine was not declared correctly. See L<perlsub>.
8e742a20 2671
a0d0e21e
LW
2672=item Illegal division by zero
2673
be771a83
GS
2674(F) You tried to divide a number by 0. Either something was wrong in
2675your logic, or you need to put a conditional in to guard against
2676meaningless input.
a0d0e21e 2677
6df41af2
GS
2678=item Illegal hexadecimal digit %s ignored
2679
be771a83
GS
2680(W digit) You may have tried to use a character other than 0 - 9 or
2681A - F, a - f in a hexadecimal number. Interpretation of the hexadecimal
2682number stopped before the illegal character.
6df41af2 2683
a0d0e21e
LW
2684=item Illegal modulus zero
2685
be771a83
GS
2686(F) You tried to divide a number by 0 to get the remainder. Most
2687numbers don't take to this kindly.
a0d0e21e 2688
6df41af2 2689=item Illegal number of bits in vec
399388f4 2690
6df41af2
GS
2691(F) The number of bits in vec() (the third argument) must be a power of
2692two from 1 to 32 (or 64, if your platform supports that).
399388f4
GS
2693
2694=item Illegal octal digit %s
a0d0e21e 2695
d1be9408 2696(F) You used an 8 or 9 in an octal number.
a0d0e21e 2697
399388f4 2698=item Illegal octal digit %s ignored
748a9306 2699
d1be9408 2700(W digit) You may have tried to use an 8 or 9 in an octal number.
75b44862 2701Interpretation of the octal number stopped before the 8 or 9.
748a9306 2702
e0e4a6e3 2703=item Illegal pattern in regex; marked by S<<-- HERE> in m/%s/
c608e803 2704
675fa9ff 2705(F) You wrote something like
c608e803
KW
2706
2707 (?+foo)
2708
2709The C<"+"> is valid only when followed by digits, indicating a
2710capturing group. See
2711L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>.
2712
375ed12a
JH
2713=item Illegal suidscript
2714
2715(F) The script run under suidperl was somehow illegal.
2716
fe13d51d 2717=item Illegal switch in PERL5OPT: -%c
6ff81951 2718
6df41af2 2719(X) The PERL5OPT environment variable may only be used to set the
646ca9b2 2720following switches: B<-[CDIMUdmtw]>.
6ff81951 2721
4003ea29
KW
2722=item Illegal user-defined property name
2723
2724(F) You specified a Unicode-like property name in a regular expression
2725pattern (using C<\p{}> or C<\P{}>) that Perl knows isn't an official
2726Unicode property, and was likely meant to be a user-defined property
2727name, but it can't be one of those, as they must begin with either C<In>
2728or C<Is>. Check the spelling. See also
2729L</Can't find Unicode property definition "%s">.
2730
6df41af2 2731=item Ill-formed CRTL environ value "%s"
81e118e0 2732
75b44862 2733(W internal) A warning peculiar to VMS. Perl tried to read the CRTL's
be771a83
GS
2734internal environ array, and encountered an element without the C<=>
2735delimiter used to separate keys from values. The element is ignored.
09bef843 2736
6df41af2 2737=item Ill-formed message in prime_env_iter: |%s|
54310121 2738
be771a83
GS
2739(W internal) A warning peculiar to VMS. Perl tried to read a logical
2740name or CLI symbol definition when preparing to iterate over %ENV, and
2741didn't see the expected delimiter between key and value, so the line was
2742ignored.
54310121 2743
6df41af2 2744=item (in cleanup) %s
9607fc9c 2745
be771a83
GS
2746(W misc) This prefix usually indicates that a DESTROY() method raised
2747the indicated exception. Since destructors are usually called by the
2748system at arbitrary points during execution, and often a vast number of
2749times, the warning is issued only once for any number of failures that
2750would otherwise result in the same message being repeated.
6df41af2 2751
be771a83
GS
2752Failure of user callbacks dispatched using the C<G_KEEPERR> flag could
2753also result in this warning. See L<perlcall/G_KEEPERR>.
9607fc9c 2754
e0e4a6e3
FC
2755=item Incomplete expression within '(?[ ])' in regex; marked by S<<-- HERE>
2756in m/%s/
0d0b4b3b 2757
675fa9ff 2758(F) There was a syntax error within the C<(?[ ])>. This can happen if the
0d0b4b3b
KW
2759expression inside the construct was completely empty, or if there are
2760too many or few operands for the number of operators. Perl is not smart
2761enough to give you a more precise indication as to what is wrong.
2762
6fbc9859
MH
2763=item Inconsistent hierarchy during C3 merge of class '%s': merging failed on
2764parent '%s'
2c7d6b9c
RGS
2765
2766(F) The method resolution order (MRO) of the given class is not
2767C3-consistent, and you have enabled the C3 MRO for this class. See the C3
2768documentation in L<mro> for more information.
2769
cdd6375d
MH
2770=item Indentation on line %d of here-doc doesn't match delimiter
2771
2772(F) You have an indented here-document where one or more of its lines
2773have whitespace at the beginning that does not match the closing
2774delimiter.
2775
2776For example, line 2 below is wrong because it does not have at least
27772 spaces, but lines 1 and 3 are fine because they have at least 2:
2778
2779 if ($something) {
2780 print <<~EOF;
2781 Line 1
2782 Line 2 not
2783 Line 3
2784 EOF
2785 }
2786
2787Note that tabs and spaces are compared strictly, meaning 1 tab will
2788not match 8 spaces.
2789
6a2ed79a 2790=item Infinite recursion in regex
1a147d38
YO
2791
2792(F) You used a pattern that references itself without consuming any input
6903afa2 2793text. You should check the pattern to ensure that recursive patterns
1a147d38
YO
2794either consume text or fail.
2795
6dbe9451
NC
2796=item Initialization of state variables in list context currently forbidden
2797
dca6023d 2798(F) C<state> only permits initializing a single scalar variable, in scalar
4c9eaea6
FC
2799context. So C<state $a = 42> is allowed, but not C<state ($a) = 42>. To apply
2800state semantics to a hash or array, store a hash or array reference in a
2801scalar variable.
6dbe9451 2802
2186f873
FC
2803=item %%s[%s] in scalar context better written as $%s[%s]
2804
2805(W syntax) In scalar context, you've used an array index/value slice
2806(indicated by %) to select a single element of an array. Generally
2807it's better to ask for a scalar value (indicated by $). The difference
2808is that C<$foo[&bar]> always behaves like a scalar, both in the value it
2809returns and when evaluating its argument, while C<%foo[&bar]> provides
2810a list context to its subscript, which can do weird things if you're
2811expecting only one subscript. When called in list context, it also
2812returns the index (what C<&bar> returns) in addition to the value.
2813
2814=item %%s{%s} in scalar context better written as $%s{%s}
2815
2816(W syntax) In scalar context, you've used a hash key/value slice
2817(indicated by %) to select a single element of a hash. Generally it's
2818better to ask for a scalar value (indicated by $). The difference
2819is that C<$foo{&bar}> always behaves like a scalar, both in the value
2820it returns and when evaluating its argument, while C<@foo{&bar}> and
2821provides a list context to its subscript, which can do weird things
2822if you're expecting only one subscript. When called in list context,
2823it also returns the key in addition to the value.
2824
a0d0e21e
LW
2825=item Insecure dependency in %s
2826
8b1a09fc 2827(F) You tried to do something that the tainting mechanism didn't like.
be771a83
GS
2828The tainting mechanism is turned on when you're running setuid or
2829setgid, or when you specify B<-T> to turn it on explicitly. The
2830tainting mechanism labels all data that's derived directly or indirectly
2831from the user, who is considered to be unworthy of your trust. If any
2832such data is used in a "dangerous" operation, you get this error. See
2833L<perlsec> for more information.
a0d0e21e
LW
2834
2835=item Insecure directory in %s
2836
be771a83
GS
2837(F) You can't use system(), exec(), or a piped open in a setuid or
2838setgid script if C<$ENV{PATH}> contains a directory that is writable by
df98f984
RGS
2839the world. Also, the PATH must not contain any relative directory.
2840See L<perlsec>.
a0d0e21e 2841
62f468fc 2842=item Insecure $ENV{%s} while running %s
a0d0e21e
LW
2843
2844(F) You can't use system(), exec(), or a piped open in a setuid or
62f468fc 2845setgid script if any of C<$ENV{PATH}>, C<$ENV{IFS}>, C<$ENV{CDPATH}>,
332d5f78
SR
2846C<$ENV{ENV}>, C<$ENV{BASH_ENV}> or C<$ENV{TERM}> are derived from data
2847supplied (or potentially supplied) by the user. The script must set
2848the path to a known value, using trustworthy data. See L<perlsec>.
a0d0e21e 2849
0e9be77f
DM
2850=item Insecure user-defined property %s
2851
2852(F) Perl detected tainted data when trying to compile a regular
2853expression that contains a call to a user-defined character property
2854function, i.e. C<\p{IsFoo}> or C<\p{InFoo}>.
2855See L<perlunicode/User-Defined Character Properties> and L<perlsec>.
2856
b9ef414d
FC
2857=item Integer overflow in format string for %s
2858
2859(F) The indexes and widths specified in the format string of C<printf()>
2860or C<sprintf()> are too large. The numbers must not overflow the size of
2861integers for your architecture.
2862
a7ae9550
GS
2863=item Integer overflow in %s number
2864
35928bc5 2865(S overflow) The hexadecimal, octal or binary number you have specified
be771a83
GS
2866either as a literal or as an argument to hex() or oct() is too big for
2867your architecture, and has been converted to a floating point number.
2868On a 32-bit architecture the largest hexadecimal, octal or binary number
9e24b6e2
JH
2869representable without overflow is 0xFFFFFFFF, 037777777777, or
28700b11111111111111111111111111111111 respectively. Note that Perl
2871transparently promotes all numbers to a floating point representation
2872internally--subject to loss of precision errors in subsequent
2873operations.
bbce6d69 2874
fc89ca81
FC
2875=item Integer overflow in srand
2876
2877(S overflow) The number you have passed to srand is too big to fit
2878in your architecture's integer representation. The number has been
2879replaced with the largest integer supported (0xFFFFFFFF on 32-bit
2880architectures). This means you may be getting less randomness than
2881you expect, because different random seeds above the maximum will
2882return the same sequence of random numbers.
2883
46314c13
JP
2884=item Integer overflow in version
2885
18da5252
FC
2886=item Integer overflow in version %d
2887
784d71ed
FC
2888(W overflow) Some portion of a version initialization is too large for
2889the size of integers for your architecture. This is not a warning
f084e84f 2890because there is no rational reason for a version to try and use an
784d71ed
FC
2891element larger than typically 2**32. This is usually caused by trying
2892to use some odd mathematical operation as a version, like 100/9.
46314c13 2893
e0e4a6e3 2894=item Internal disaster in regex; marked by S<<-- HERE> in m/%s/
6df41af2
GS
2895
2896(P) Something went badly wrong in the regular expression parser.
e0e4a6e3 2897The S<<-- HERE> shows whereabouts in the regular expression the problem was
b45f050a
JF
2898discovered.
2899
748a9306
LW
2900=item Internal inconsistency in tracking vforks
2901
be771a83
GS
2902(S) A warning peculiar to VMS. Perl keeps track of the number of times
2903you've called C<fork> and C<exec>, to determine whether the current call
2904to C<exec> should affect the current script or a subprocess (see
2905L<perlvms/"exec LIST">). Somehow, this count has become scrambled, so
2906Perl is making a guess and treating this C<exec> as a request to
2907terminate the Perl script and execute the specified command.
748a9306 2908
870978ae
FC
2909=item internal %<num>p might conflict with future printf extensions
2910
2911(S internal) Perl's internal routine that handles C<printf> and C<sprintf>
2912formatting follows a slightly different set of rules when called from
2913C or XS code. Specifically, formats consisting of digits followed
2914by "p" (e.g., "%7p") are reserved for future use. If you see this
2915message, then an XS module tried to call that routine with one such
2916reserved format.
2917
e0e4a6e3 2918=item Internal urp in regex; marked by S<<-- HERE> in m/%s/
b45f050a 2919
fa816bf3 2920(P) Something went badly awry in the regular expression parser. The
e0e4a6e3 2921S<<-- HERE> shows whereabouts in the regular expression the problem was
7253e4e3 2922discovered.
a0d0e21e 2923
6df41af2
GS
2924=item %s (...) interpreted as function
2925
75b44862 2926(W syntax) You've run afoul of the rule that says that any list operator
be771a83 2927followed by parentheses turns into a function, with all the list
64977eb6 2928operators arguments found inside the parentheses. See
13a2d996 2929L<perlop/Terms and List Operators (Leftward)>.
6df41af2 2930
f51551f7
FC
2931=item In '(?...)', the '(' and '?' must be adjacent in regex;
2932marked by S<<-- HERE> in m/%s/
2933
2934(F) The two-character sequence C<"(?"> in this context in a regular
2935expression pattern should be an indivisible token, with nothing
2936intervening between the C<"("> and the C<"?">, but you separated them
2937with whitespace.
2938
09bef843
SB
2939=item Invalid %s attribute: %s
2940
a4a4c9e2 2941(F) The indicated attribute for a subroutine or variable was not recognized
09bef843
SB
2942by Perl or by a user-supplied handler. See L<attributes>.
2943
2944=item Invalid %s attributes: %s
2945
a4a4c9e2 2946(F) The indicated attributes for a subroutine or variable were not
be771a83 2947recognized by Perl or by a user-supplied handler. See L<attributes>.
09bef843 2948
e0e4a6e3
FC
2949=item Invalid character in charnames alias definition; marked by
2950S<<-- HERE> in '%s
225fb84f
KW
2951
2952(F) You tried to create a custom alias for a character name, with
2953the C<:alias> option to C<use charnames> and the specified character in
2954the indicated name isn't valid. See L<charnames/CUSTOM ALIASES>.
2955
c8028aa6
TC
2956=item Invalid \0 character in %s for %s: %s\0%s
2957
fa3234e3
FC
2958(W syscalls) Embedded \0 characters in pathnames or other system call
2959arguments produce a warning as of 5.20. The parts after the \0 were
2960formerly ignored by system calls.
c8028aa6 2961
e0e4a6e3 2962=item Invalid character in \N{...}; marked by S<<-- HERE> in \N{%s}
a690c7c4
FC
2963
2964(F) Only certain characters are valid for character names. The
2965indicated one isn't. See L<charnames/CUSTOM ALIASES>.
2966
c635e13b
PP
2967=item Invalid conversion in %s: "%s"
2968
be771a83
GS
2969(W printf) Perl does not understand the given format conversion. See
2970L<perlfunc/sprintf>.
c635e13b 2971
e0e4a6e3
FC
2972=item Invalid escape in the specified encoding in regex; marked by
2973S<<-- HERE> in m/%s/
9e08bc66 2974
98d31c73 2975(W regexp)(F) The numeric escape (for example C<\xHH>) of value < 256
9e08bc66
ST
2976didn't correspond to a single character through the conversion
2977from the encoding specified by the encoding pragma.
98d31c73
FC
2978The escape was replaced with REPLACEMENT CHARACTER (U+FFFD)
2979instead, except within S<C<(?[ ])>>, where it is a fatal error.
e0e4a6e3 2980The S<<-- HERE> shows whereabouts in the regular expression the
9e08bc66
ST
2981escape was discovered.
2982
8149aa9f
FC
2983=item Invalid hexadecimal number in \N{U+...}
2984
e0e4a6e3
FC
2985=item Invalid hexadecimal number in \N{U+...} in regex; marked by
2986S<<-- HERE> in m/%s/
aec0ef10 2987
8149aa9f 2988(F) The character constant represented by C<...> is not a valid hexadecimal
74f8e9e3
FC
2989number. Either it is empty, or you tried to use a character other than
29900 - 9 or A - F, a - f in a hexadecimal number.
8149aa9f 2991
6651ba0b
FC
2992=item Invalid module name %s with -%c option: contains single ':'
2993
2994(F) The module argument to perl's B<-m> and B<-M> command-line options
2995cannot contain single colons in the module name, but only in the
2996arguments after "=". In other words, B<-MFoo::Bar=:baz> is ok, but
2997B<-MFoo:Bar=baz> is not.
2998
2c7d6b9c
RGS
2999=item Invalid mro name: '%s'
3000
162a3e34
FC
3001(F) You tried to C<mro::set_mro("classname", "foo")> or C<use mro 'foo'>,
3002where C<foo> is not a valid method resolution order (MRO). Currently,
3003the only valid ones supported are C<dfs> and C<c3>, unless you have loaded
3004a module that is a MRO plugin. See L<mro> and L<perlmroapi>.
2c7d6b9c 3005
40e4140b
FC
3006=item Invalid negative number (%s) in chr
3007
3008(W utf8) You passed a negative number to C<chr>. Negative numbers are
abc0aa9d 3009not valid character numbers, so it returns the Unicode replacement
40e4140b
FC
3010character (U+FFFD).
3011
74d1b2e4
FC
3012=item Invalid number '%s' for -C option.
3013
3014(F) You supplied a number to the -C option that either has extra leading
3015zeroes or overflows perl's unsigned integer representation.
3016
6651ba0b
FC
3017=item invalid option -D%c, use -D'' to see choices
3018
8ff21bfe
FC
3019(S debugging) Perl was called with invalid debugger flags. Call perl
3020with the B<-D> option with no flags to see the list of acceptable values.
982c4ecb 3021See also L<perlrun/-Dletters>.
6651ba0b 3022
6e8a73f2 3023=item Invalid quantifier in {,} in regex; marked by S<<-- HERE> in m/%s/
35cd12d1
HS
3024
3025(F) The pattern looks like a {min,max} quantifier, but the min or max
3026could not be parsed as a valid number - either it has leading zeroes,
3027or it represents too big a number to cope with. The S<<-- HERE> shows
3028where in the regular expression the problem was discovered. See L<perlre>.
3029
e0e4a6e3 3030=item Invalid [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
6df41af2
GS
3031
3032(F) The range specified in a character class had a minimum character
7253e4e3
RK
3033greater than the maximum character. One possibility is that you forgot the
3034C<{}> from your ending C<\x{}> - C<\x> without the curly braces can go only
e0e4a6e3 3035up to C<ff>. The S<<-- HERE> shows whereabouts in the regular expression the
7253e4e3 3036problem was discovered. See L<perlre>.
6df41af2 3037
d1573ac7 3038=item Invalid range "%s" in transliteration operator
c2e66d9e
GS
3039
3040(F) The range specified in the tr/// or y/// operator had a minimum
3041character greater than the maximum character. See L<perlop>.
3042
09bef843
SB
3043=item Invalid separator character %s in attribute list
3044
0120eecf 3045(F) Something other than a colon or whitespace was seen between the
be771a83
GS
3046elements of an attribute list. If the previous attribute had a
3047parenthesised parameter list, perhaps that list was terminated too soon.
3048See L<attributes>.
09bef843 3049
b4581f09
JH
3050=item Invalid separator character %s in PerlIO layer specification %s
3051
2bfc5f71
FC
3052(W layer) When pushing layers onto the Perl I/O system, something other
3053than a colon or whitespace was seen between the elements of a layer list.
b4581f09
JH
3054If the previous attribute had a parenthesised parameter list, perhaps that
3055list was terminated too soon.
3056
2c86d456
DG
3057=item Invalid strict version format (%s)
3058
fa816bf3 3059(F) A version number did not meet the "strict" criteria for versions.
2c86d456
DG
3060A "strict" version number is a positive decimal number (integer or
3061decimal-fraction) without exponentiation or else a dotted-decimal
3062v-string with a leading 'v' character and at least three components.
a6485a24 3063The parenthesized text indicates which criteria were not met.
2c86d456
DG
3064See the L<version> module for more details on allowed version formats.
3065
49704364 3066=item Invalid type '%s' in %s
96e4d5b1 3067
49704364
LW
3068(F) The given character is not a valid pack or unpack type.
3069See L<perlfunc/pack>.
6728c851 3070
49704364 3071(W) The given character is not a valid pack or unpack type but used to be
75b44862 3072silently ignored.
96e4d5b1 3073
2c86d456
DG
3074=item Invalid version format (%s)
3075
fa816bf3 3076(F) A version number did not meet the "lax" criteria for versions.
2c86d456
DG
3077A "lax" version number is a positive decimal number (integer or
3078decimal-fraction) without exponentiation or else a dotted-decimal
fa816bf3
FC
3079v-string. If the v-string has fewer than three components, it
3080must have a leading 'v' character. Otherwise, the leading 'v' is
3081optional. Both decimal and dotted-decimal versions may have a
3082trailing "alpha" component separated by an underscore character
3083after a fractional or dotted-decimal component. The parenthesized
3084text indicates which criteria were not met. See the L<version> module
3085for more details on allowed version formats.
46314c13 3086
798ae1b7
DG
3087=item Invalid version object
3088
fa816bf3
FC
3089(F) The internal structure of the version object was invalid.
3090Perhaps the internals were modified directly in some way or
3091an arbitrary reference was blessed into the "version" class.
798ae1b7 3092
cd209d9d 3093=item In '(*VERB...)', the '(' and '*' must be adjacent in regex;
e0e4a6e3 3094marked by S<<-- HERE> in m/%s/
675fa9ff 3095
cd209d9d 3096(F) The two-character sequence C<"(*"> in
675fa9ff
FC
3097this context in a regular expression pattern should be an
3098indivisible token, with nothing intervening between the C<"(">
cd209d9d 3099and the C<"*">, but you separated them.
675fa9ff 3100
a0d0e21e
LW
3101=item ioctl is not implemented
3102
3103(F) Your machine apparently doesn't implement ioctl(), which is pretty
3104strange for a machine that supports C.
3105
c289d2f7
JH
3106=item ioctl() on unopened %s
3107
3108(W unopened) You tried ioctl() on a filehandle that was never opened.
34b6fd5e 3109Check your control flow and number of arguments.
c289d2f7 3110
fe13d51d 3111=item IO layers (like '%s') unavailable
363c40c4
SB
3112
3113(F) Your Perl has not been configured to have PerlIO, and therefore
34b6fd5e 3114you cannot use IO layers. To have PerlIO, Perl must be configured
363c40c4
SB
3115with 'useperlio'.
3116
80cbd5ad
JH
3117=item IO::Socket::atmark not implemented on this architecture
3118
3119(F) Your machine doesn't implement the sockatmark() functionality,
34b6fd5e 3120neither as a system call nor an ioctl call (SIOCATMARK).
80cbd5ad 3121
6e8a73f2 3122=item '%s' is an unknown bound type in regex; marked by S<<-- HERE> in m/%s/
64935bc6
KW
3123
3124(F) You used C<\b{...}> or C<\B{...}> and the C<...> is not known to
3125Perl. The current valid ones are given in
3126L<perlrebackslash/\b{}, \b, \B{}, \B>.
3127
1972ac5c 3128=item %s() is deprecated on :utf8 handles. This will be a fatal error in Perl 5.30
74d1b2e4 3129
dd6d5da4 3130(D deprecated) The sysread(), recv(), syswrite() and send() operators are
74d1b2e4
FC
3131deprecated on handles that have the C<:utf8> layer, either explicitly, or
3132implicitly, eg., with the C<:encoding(UTF-16LE)> layer.
3133
3134Both sysread() and recv() currently use only the C<:utf8> flag for the stream,
3135ignoring the actual layers. Since sysread() and recv() do no UTF-8
3136validation they can end up creating invalidly encoded scalars.
3137
3138Similarly, syswrite() and send() use only the C<:utf8> flag, otherwise ignoring
3139any layers. If the flag is set, both write the value UTF-8 encoded, even if
3140the layer is some different encoding, such as the example above.
3141
3142Ideally, all of these operators would completely ignore the C<:utf8> state,
3143working only with bytes, but this would result in silently breaking existing
1972ac5c
A
3144code.
3145
3146In Perl 5.30, it will no longer be possible to use sysread(), recv(),
3147syswrite() or send() to read or send bytes from/to :utf8 handles.
74d1b2e4 3148
d4360efa 3149=item "%s" is more clearly written simply as "%s" in regex; marked by S<<-- HERE> in m/%s/
acdfc3b6 3150
d4360efa 3151(W regexp) (only under C<S<use re 'strict'>> or within C<(?[...])>)
30b17cc1
A
3152
3153You specified a character that has the given plainer way of writing it,
3154and which is also portable to platforms running with different character
d4360efa 3155sets.
acdfc3b6 3156
37398dc1 3157=item $* is no longer supported. Its use will be fatal in Perl 5.30
a678626e
A
3158
3159(D deprecated, syntax) The special variable C<$*>, deprecated in older
3160perls, has been removed as of 5.10.0 and is no longer supported. In
3161previous versions of perl the use of C<$*> enabled or disabled multi-line
3162matching within a string.
3163
3164Instead of using C<$*> you should use the C</m> (and maybe C</s>) regexp
3165modifiers. You can enable C</m> for a lexical scope (even a whole file)
3166with C<use re '/m'>. (In older versions: when C<$*> was set to a true value
3167then all regular expressions behaved as if they were written using C</m>.)
3168
37398dc1
A
3169Use of this variable will be a fatal error in Perl 5.30.
3170
3171=item $# is no longer supported. Its use will be fatal in Perl 5.30
a678626e
A
3172
3173(D deprecated, syntax) The special variable C<$#>, deprecated in older
3174perls, has been removed as of 5.10.0 and is no longer supported. You
3175should use the printf/sprintf functions instead.
3176
37398dc1
A
3177Use of this variable will be a fatal error in Perl 5.30.
3178
ccf3535a 3179=item '%s' is not a code reference
6ad11d81 3180
6903afa2
FC
3181(W overload) The second (fourth, sixth, ...) argument of
3182overload::constant needs to be a code reference. Either
3183an anonymous subroutine, or a reference to a subroutine.
6ad11d81 3184
ccf3535a 3185=item '%s' is not an overloadable type
6ad11d81 3186
04a80ee0
RGS
3187(W overload) You tried to overload a constant type the overload package is
3188unaware of.
6ad11d81 3189
5a25739d
FC
3190=item -i used with no filenames on the command line, reading from STDIN
3191
3192(S inplace) The C<-i> option was passed on the command line, indicating
3193that the script is intended to edit files in place, but no files were
3194given. This is usually a mistake, since editing STDIN in place doesn't
3195make sense, and can be confusing because it can make perl look like
3196it is hanging when it is really just trying to read from STDIN. You
3197should either pass a filename to edit, or remove C<-i> from the command
3198line. See L<perlrun> for more details.
3199
aec0ef10 3200=item Junk on end of regexp in regex m/%s/
a0d0e21e
LW
3201
3202(P) The regular expression parser is confused.
3203
3204=item Label not found for "last %s"
3205
be771a83
GS
3206(F) You named a loop to break out of, but you're not currently in a loop
3207of that name, not even if you count where you were called from. See
3208L<perlfunc/last>.
a0d0e21e
LW
3209
3210=item Label not found for "next %s"
3211
3212(F) You named a loop to continue, but you're not currently in a loop of
3213that name, not even if you count where you were called from. See
3214L<perlfunc/last>.
3215
3216=item Label not found for "redo %s"
3217
3218(F) You named a loop to restart, but you're not currently in a loop of
3219that name, not even if you count where you were called from. See
3220L<perlfunc/last>.
3221
85ab1d1d 3222=item leaving effective %s failed
5ff3f7a4 3223
85ab1d1d 3224(F) While under the C<use filetest> pragma, switching the real and
5ff3f7a4
GS
3225effective uids or gids failed.
3226
49704364
LW
3227=item length/code after end of string in unpack
3228
d7f8936a 3229(F) While unpacking, the string buffer was already used up when an unpack
6903afa2
FC
3230length/code combination tried to obtain more data. This results in
3231an undefined value for the length. See L<perlfunc/pack>.
49704364 3232
25e26107 3233=item length() used on %s (did you mean "scalar(%s)"?)
e508c8a4 3234
0d46a4e7
FC
3235(W syntax) You used length() on either an array or a hash when you
3236probably wanted a count of the items.
e508c8a4
MH
3237
3238Array size can be obtained by doing:
3239
3240 scalar(@array);
3241
3242The number of items in a hash can be obtained by doing:
3243
3244 scalar(keys %hash);
3245
f0e67a1d
Z
3246=item Lexing code attempted to stuff non-Latin-1 character into Latin-1 input
3247
d4fe7078
RS
3248(F) An extension is attempting to insert text into the current parse
3249(using L<lex_stuff_pvn|perlapi/lex_stuff_pvn> or similar), but tried to insert a character that
3250couldn't be part of the current input. This is an inherent pitfall
3251of the stuffing mechanism, and one of the reasons to avoid it. Where
6903afa2 3252it is necessary to stuff, stuffing only plain ASCII is recommended.
f0e67a1d
Z
3253
3254=item Lexing code internal error (%s)
3255
3256(F) Lexing code supplied by an extension violated the lexer's API in a
3257detectable way.
3258
69282e91 3259=item listen() on closed socket %s
a0d0e21e 3260
be771a83
GS
3261(W closed) You tried to do a listen on a closed socket. Did you forget
3262to check the return value of your socket() call? See
3263L<perlfunc/listen>.
a0d0e21e 3264
6651ba0b
FC
3265=item List form of piped open not implemented
3266
3267(F) On some platforms, notably Windows, the three-or-more-arguments
3268form of C<open> does not support pipes, such as C<open($pipe, '|-', @args)>.
3269Use the two-argument C<open($pipe, '|prog arg1 arg2...')> form instead.
3270
dc6bb7ba
FC
3271=item %s: loadable library and perl binaries are mismatched (got handshake key %p, needed %p)
3272
3273(P) A dynamic loading library C<.so> or C<.dll> was being loaded into the
3274process that was built against a different build of perl than the
3275said library was compiled against. Reinstalling the XS module will
3276likely fix this error.
3277
8c6180a9
KW
3278=item Locale '%s' may not work well.%s
3279
780fcc9f 3280(W locale) You are using the named locale, which is a non-UTF-8 one, and
dae67c56
KW
3281which perl has determined is not fully compatible with what it can
3282handle. The second C<%s> gives a reason.
8c6180a9
KW
3283
3284By far the most common reason is that the locale has characters in it
3285that are represented by more than one byte. The only such locales that
3286Perl can handle are the UTF-8 locales. Most likely the specified locale
3287is a non-UTF-8 one for an East Asian language such as Chinese or
3288Japanese. If the locale is a superset of ASCII, the ASCII portion of it
780fcc9f 3289may work in Perl.
8c6180a9
KW
3290
3291Some essentially obsolete locales that aren't supersets of ASCII, mainly
3292those in ISO 646 or other 7-bit locales, such as ASMO 449, can also have
3293problems, depending on what portions of the ASCII character set get
3294changed by the locale and are also used by the program.
3295The warning message lists the determinable conflicting characters.
3296
780fcc9f
KW
3297Note that not all incompatibilities are found.
3298
3299If this happens to you, there's not much you can do except switch to use a
3300different locale or use L<Encode> to translate from the locale into
3301UTF-8; if that's impracticable, you have been warned that some things
3302may break.
3303
3304This message is output once each time a bad locale is switched into
3305within the scope of C<S<use locale>>, or on the first possibly-affected
3306operation if the C<S<use locale>> inherits a bad one. It is not raised
3307for any operations from the L<POSIX> module.
3308
a2162cd9
FC
3309=item localtime(%f) failed
3310
3311(W overflow) You called C<localtime> with a number that it could not handle:
3312too large, too small, or NaN. The returned value is C<undef>.
3313
3314=item localtime(%f) too large
3315
3316(W overflow) You called C<localtime> with a number that was larger
3317than it can reliably handle and C<localtime> probably returned the
3318wrong date. This warning is also triggered with NaN (the special
3319not-a-number value).
3320
3321=item localtime(%f) too small
3322
3323(W overflow) You called C<localtime> with a number that was smaller
3324than it can reliably handle and C<localtime> probably returned the
3325wrong date.
3326
58e23c8d 3327=item Lookbehind longer than %d not implemented in regex m/%s/
b45f050a
JF
3328
3329(F) There is currently a limit on the length of string which lookbehind can
6903afa2 3330handle. This restriction may be eased in a future release.
2e50fd82 3331
b88df990
NC
3332=item Lost precision when %s %f by 1
3333
e63e8a91
FC
3334(W imprecision) The value you attempted to increment or decrement by one
3335is too large for the underlying floating point representation to store
3336accurately, hence the target of C<++> or C<--> is unchanged. Perl issues this
3337warning because it has already switched from integers to floating point
3338when values are too large for integers, and now even floating point is
3339insufficient. You may wish to switch to using L<Math::BigInt> explicitly.
b88df990 3340
93fad930 3341=item lstat() on filehandle%s
2f7da168
RK
3342
3343(W io) You tried to do an lstat on a filehandle. What did you mean
3344by that? lstat() makes sense only on filenames. (Perl did a fstat()
3345instead on the filehandle.)
3346
345d70e3 3347=item lvalue attribute %s already-defined subroutine
bb3abb05 3348
345d70e3
FC
3349(W misc) Although L<attributes.pm|attributes> allows this, turning the lvalue
3350attribute on or off on a Perl subroutine that is already defined
3351does not always work properly. It may or may not do what you
3352want, depending on what code is inside the subroutine, with exact
3353details subject to change between Perl versions. Only do this
3354if you really know what you are doing.
bb3abb05 3355
885ef6f5
GG
3356=item lvalue attribute ignored after the subroutine has been defined
3357
345d70e3
FC
3358(W misc) Using the C<:lvalue> declarative syntax to make a Perl
3359subroutine an lvalue subroutine after it has been defined is
3360not permitted. To make the subroutine an lvalue subroutine,
3361add the lvalue attribute to the definition, or put the C<sub
3362foo :lvalue;> declaration before the definition.
3363
3364See also L<attributes.pm|attributes>.
885ef6f5 3365
6f1b3ab0
FC
3366=item Magical list constants are not supported
3367
3368(F) You assigned a magical array to a stash element, and then tried
3369to use the subroutine from the same slot. You are asking Perl to do
3370something it cannot do, details subject to change between Perl versions.
3371
2db62bbc 3372=item Malformed integer in [] in pack
49704364 3373
2db62bbc 3374(F) Between the brackets enclosing a numeric repeat count only digits
49704364
LW
3375are permitted. See L<perlfunc/pack>.
3376
3377=item Malformed integer in [] in unpack
3378
2db62bbc 3379(F) Between the brackets enclosing a numeric repeat count only digits
49704364
LW
3380are permitted. See L<perlfunc/pack>.
3381
6df41af2
GS
3382=item Malformed PERLLIB_PREFIX
3383
3384(F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form
3385