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Add warning message for locale/Unicode intermixing
[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
6df41af2 75=item Ambiguous call resolved as CORE::%s(), qualify as such or use &
43192e07 76
75b44862 77(W ambiguous) A subroutine you have declared has the same name as a Perl
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78keyword, and you have used the name without qualification for calling
79one or the other. Perl decided to call the builtin because the
80subroutine is not imported.
43192e07 81
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82To force interpretation as a subroutine call, either put an ampersand
83before the subroutine name, or qualify the name with its package.
84Alternatively, you can import the subroutine (or pretend that it's
85imported with the C<use subs> pragma).
43192e07 86
6df41af2 87To silently interpret it as the Perl operator, use the C<CORE::> prefix
496a33f5 88on the operator (e.g. C<CORE::log($x)>) or declare the subroutine
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89to be an object method (see L<perlsub/"Subroutine Attributes"> or
90L<attributes>).
43192e07 91
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92=item Ambiguous range in transliteration operator
93
94(F) You wrote something like C<tr/a-z-0//> which doesn't mean anything at
95all. To include a C<-> character in a transliteration, put it either
96first or last. (In the past, C<tr/a-z-0//> was synonymous with
97C<tr/a-y//>, which was probably not what you would have expected.)
98
6df41af2 99=item Ambiguous use of %s resolved as %s
43192e07 100
7c7af292 101(S ambiguous) You said something that may not be interpreted the way
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102you thought. Normally it's pretty easy to disambiguate it by supplying
103a missing quote, operator, parenthesis pair or declaration.
a0d0e21e 104
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105=item Ambiguous use of -%s resolved as -&%s()
106
107(S ambiguous) You wrote something like C<-foo>, which might be the
108string C<"-foo">, or a call to the function C<foo>, negated. If you meant
109the string, just write C<"-foo">. If you meant the function call,
110write C<-foo()>.
111
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112=item Ambiguous use of %c resolved as operator %c
113
7c7af292 114(S ambiguous) C<%>, C<&>, and C<*> are both infix operators (modulus,
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115bitwise and, and multiplication) I<and> initial special characters
116(denoting hashes, subroutines and typeglobs), and you said something
117like C<*foo * foo> that might be interpreted as either of them. We
118assumed you meant the infix operator, but please try to make it more
119clear -- in the example given, you might write C<*foo * foo()> if you
120really meant to multiply a glob by the result of calling a function.
d8225693 121
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122=item Ambiguous use of %c{%s} resolved to %c%s
123
124(W ambiguous) You wrote something like C<@{foo}>, which might be
125asking for the variable C<@foo>, or it might be calling a function
126named foo, and dereferencing it as an array reference. If you wanted
1cecf2c0 127the variable, you can just write C<@foo>. If you wanted to call the
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128function, write C<@{foo()}> ... or you could just not have a variable
129and a function with the same name, and save yourself a lot of trouble.
130
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131=item Ambiguous use of %c{%s[...]} resolved to %c%s[...]
132
133=item Ambiguous use of %c{%s{...}} resolved to %c%s{...}
4da60377 134
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135(W ambiguous) You wrote something like C<${foo[2]}> (where foo represents
136the name of a Perl keyword), which might be looking for element number
1372 of the array named C<@foo>, in which case please write C<$foo[2]>, or you
138might have meant to pass an anonymous arrayref to the function named
139foo, and then do a scalar deref on the value it returns. If you meant
140that, write C<${foo([2])}>.
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141
142In regular expressions, the C<${foo[2]}> syntax is sometimes necessary
143to disambiguate between array subscripts and character classes.
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144C</$length[2345]/>, for instance, will be interpreted as C<$length> followed
145by the character class C<[2345]>. If an array subscript is what you
146want, you can avoid the warning by changing C</${length[2345]}/> to the
147unsightly C</${\$length[2345]}/>, by renaming your array to something
148that does not coincide with a built-in keyword, or by simply turning
149off warnings with C<no warnings 'ambiguous';>.
4da60377 150
6df41af2 151=item '|' and '<' may not both be specified on command line
a0d0e21e 152
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153(F) An error peculiar to VMS. Perl does its own command line
154redirection, and found that STDIN was a pipe, and that you also tried to
155redirect STDIN using '<'. Only one STDIN stream to a customer, please.
c9f97d15 156
6df41af2 157=item '|' and '>' may not both be specified on command line
1028017a 158
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159(F) An error peculiar to VMS. Perl does its own command line
160redirection, and thinks you tried to redirect stdout both to a file and
161into a pipe to another command. You need to choose one or the other,
162though nothing's stopping you from piping into a program or Perl script
163which 'splits' output into two streams, such as
1028017a 164
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165 open(OUT,">$ARGV[0]") or die "Can't write to $ARGV[0]: $!";
166 while (<STDIN>) {
167 print;
168 print OUT;
169 }
170 close OUT;
c9f97d15 171
6df41af2 172=item Applying %s to %s will act on scalar(%s)
eb6e2d6f 173
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174(W misc) The pattern match (C<//>), substitution (C<s///>), and
175transliteration (C<tr///>) operators work on scalar values. If you apply
be771a83 176one of them to an array or a hash, it will convert the array or hash to
ac036724 177a scalar value (the length of an array, or the population info of a
178hash) and then work on that scalar value. This is probably not what
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179you meant to do. See L<perlfunc/grep> and L<perlfunc/map> for
180alternatives.
eb6e2d6f 181
6df41af2 182=item Arg too short for msgsnd
76cd736e 183
6df41af2 184(F) msgsnd() requires a string at least as long as sizeof(long).
76cd736e 185
f86702cc 186=item Argument "%s" isn't numeric%s
a0d0e21e 187
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188(W numeric) The indicated string was fed as an argument to an operator
189that expected a numeric value instead. If you're fortunate the message
190will identify which operator was so unfortunate.
a0d0e21e 191
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192=item Argument list not closed for PerlIO layer "%s"
193
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194(W layer) When pushing a layer with arguments onto the Perl I/O
195system you forgot the ) that closes the argument list. (Layers
196take care of transforming data between external and internal
197representations.) Perl stopped parsing the layer list at this
198point and did not attempt to push this layer. If your program
199didn't explicitly request the failing operation, it may be the
200result of the value of the environment variable PERLIO.
b4581f09 201
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202=item Argument "%s" treated as 0 in increment (++)
203
204(W numeric) The indicated string was fed as an argument to the C<++>
205operator which expects either a number or a string matching
206C</^[a-zA-Z]*[0-9]*\z/>. See L<perlop/Auto-increment and
207Auto-decrement> for details.
208
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209=item assertion botched: %s
210
21b5e840 211(X) The malloc package that comes with Perl had an internal failure.
a0d0e21e 212
0eacef8e 213=item Assertion %s failed: file "%s", line %d
a0d0e21e 214
21b5e840 215(X) A general assertion failed. The file in question must be examined.
a0d0e21e 216
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217=item Assigned value is not a reference
218
219(F) You tried to assign something that was not a reference to an lvalue
220reference (e.g., C<\$x = $y>). If you meant to make $x an alias to $y, use
221C<\$x = \$y>.
222
223=item Assigned value is not %s reference
224
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225(F) You tried to assign a reference to a reference constructor, but the
226two references were not of the same type. You cannot alias a scalar to
227an array, or an array to a hash; the two types must match.
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228
229 \$x = \@y; # error
230 \@x = \%y; # error
231 $y = [];
232 \$x = $y; # error; did you mean \$y?
233
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234=item Assigning non-zero to $[ is no longer possible
235
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236(F) When the "array_base" feature is disabled (e.g., under C<use v5.16;>)
237the special variable C<$[>, which is deprecated, is now a fixed zero value.
82122228 238
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239=item Assignment to both a list and a scalar
240
241(F) If you assign to a conditional operator, the 2nd and 3rd arguments
242must either both be scalars or both be lists. Otherwise Perl won't
243know which context to supply to the right side.
244
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245=item <> at require-statement should be quotes
246
247(F) You wrote C<< require <file> >> when you should have written
248C<require 'file'>.
249
2393f1b9 250=item Attempt to access disallowed key '%s' in a restricted hash
1b1f1335 251
49293501 252(F) The failing code has attempted to get or set a key which is not in
2393f1b9 253the current set of allowed keys of a restricted hash.
49293501 254
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255=item Attempt to bless into a freed package
256
257(F) You wrote C<bless $foo> with one argument after somehow causing
258the current package to be freed. Perl cannot figure out what to
259do, so it throws up in hands in despair.
260
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261=item Attempt to bless into a reference
262
263(F) The CLASSNAME argument to the bless() operator is expected to be
57dedab9 264the name of the package to bless the resulting object into. You've
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265supplied instead a reference to something: perhaps you wrote
266
267 bless $self, $proto;
268
269when you intended
270
271 bless $self, ref($proto) || $proto;
272
273If you actually want to bless into the stringified version
274of the reference supplied, you need to stringify it yourself, for
275example by:
276
277 bless $self, "$proto";
278
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279=item Attempt to clear deleted array
280
281(S debugging) An array was assigned to when it was being freed.
282Freed values are not supposed to be visible to Perl code. This
283can also happen if XS code calls C<av_clear> from a custom magic
284callback on the array.
285
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286=item Attempt to delete disallowed key '%s' from a restricted hash
287
288(F) The failing code attempted to delete from a restricted hash a key
289which is not in its key set.
290
291=item Attempt to delete readonly key '%s' from a restricted hash
292
293(F) The failing code attempted to delete a key whose value has been
294declared readonly from a restricted hash.
295
de42a5a9 296=item Attempt to free non-arena SV: 0x%x
a0d0e21e 297
f84fe999 298(S internal) All SV objects are supposed to be allocated from arenas
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299that will be garbage collected on exit. An SV was discovered to be
300outside any of those arenas.
a0d0e21e 301
12578ffb 302=item Attempt to free nonexistent shared string '%s'%s
bbce6d69 303
f84fe999 304(S internal) Perl maintains a reference-counted internal table of
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305strings to optimize the storage and access of hash keys and other
306strings. This indicates someone tried to decrement the reference count
307of a string that can no longer be found in the table.
bbce6d69 308
7d5b40b4 309=item Attempt to free temp prematurely: SV 0x%x
a0d0e21e 310
f84fe999 311(S debugging) Mortalized values are supposed to be freed by the
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312free_tmps() routine. This indicates that something else is freeing the
313SV before the free_tmps() routine gets a chance, which means that the
314free_tmps() routine will be freeing an unreferenced scalar when it does
315try to free it.
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316
317=item Attempt to free unreferenced glob pointers
318
f84fe999 319(S internal) The reference counts got screwed up on symbol aliases.
a0d0e21e 320
7d5b40b4 321=item Attempt to free unreferenced scalar: SV 0x%x
a0d0e21e 322
8f7e4d2c 323(S internal) Perl went to decrement the reference count of a scalar to
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324see if it would go to 0, and discovered that it had already gone to 0
325earlier, and should have been freed, and in fact, probably was freed.
326This could indicate that SvREFCNT_dec() was called too many times, or
327that SvREFCNT_inc() was called too few times, or that the SV was
328mortalized when it shouldn't have been, or that memory has been
329corrupted.
a0d0e21e 330
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331=item Attempt to pack pointer to temporary value
332
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333(W pack) You tried to pass a temporary value (like the result of a
334function, or a computed expression) to the "p" pack() template. This
335means the result contains a pointer to a location that could become
336invalid anytime, even before the end of the current statement. Use
337literals or global values as arguments to the "p" pack() template to
338avoid this warning.
84902520 339
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340=item Attempt to reload %s aborted.
341
342(F) You tried to load a file with C<use> or C<require> that failed to
343compile once already. Perl will not try to compile this file again
344unless you delete its entry from %INC. See L<perlfunc/require> and
345L<perlvar/%INC>.
346
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347=item Attempt to set length of freed array
348
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349(W misc) You tried to set the length of an array which has
350been freed. You can do this by storing a reference to the
351scalar representing the last index of an array and later
352assigning through that reference. For example
1b20cd17
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353
354 $r = do {my @a; \$#a};
355 $$r = 503
356
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357=item Attempt to use reference as lvalue in substr
358
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359(W substr) You supplied a reference as the first argument to substr()
360used as an lvalue, which is pretty strange. Perhaps you forgot to
361dereference it first. See L<perlfunc/substr>.
b7a902f4 362
c32124fe
NC
363=item Attribute "locked" is deprecated
364
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365(D deprecated) You have used the attributes pragma to modify the
366"locked" attribute on a code reference. The :locked attribute is
367obsolete, has had no effect since 5005 threads were removed, and
368will be removed in a future release of Perl 5.
c32124fe 369
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370=item Attribute prototype(%s) discards earlier prototype attribute in same sub
371
372(W misc) A sub was declared as sub foo : prototype(A) : prototype(B) {}, for
373example. Since each sub can only have one prototype, the earlier
374declaration(s) are discarded while the last one is applied.
375
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376=item Attribute "unique" is deprecated
377
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378(D deprecated) You have used the attributes pragma to modify
379the "unique" attribute on an array, hash or scalar reference.
380The :unique attribute has had no effect since Perl 5.8.8, and
381will be removed in a future release of Perl 5.
f1a3ce43 382
ccce04a4
FC
383=item av_reify called on tied array
384
385(S debugging) This indicates that something went wrong and Perl got I<very>
386confused about C<@_> or C<@DB::args> being tied.
387
de42a5a9 388=item Bad arg length for %s, is %u, should be %d
a0d0e21e 389
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390(F) You passed a buffer of the wrong size to one of msgctl(), semctl()
391or shmctl(). In C parlance, the correct sizes are, respectively,
5f05dabc 392S<sizeof(struct msqid_ds *)>, S<sizeof(struct semid_ds *)>, and
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393S<sizeof(struct shmid_ds *)>.
394
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395=item Bad evalled substitution pattern
396
496a33f5 397(F) You've used the C</e> switch to evaluate the replacement for a
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398substitution, but perl found a syntax error in the code to evaluate,
399most likely an unexpected right brace '}'.
400
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401=item Bad filehandle: %s
402
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403(F) A symbol was passed to something wanting a filehandle, but the
404symbol has no filehandle associated with it. Perhaps you didn't do an
405open(), or did it in another package.
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406
407=item Bad free() ignored
408
be771a83 409(S malloc) An internal routine called free() on something that had never
fa816bf3 410been malloc()ed in the first place. Mandatory, but can be disabled by
9ea8bc6d 411setting environment variable C<PERL_BADFREE> to 0.
33c8a3fe 412
9ea8bc6d 413This message can be seen quite often with DB_File on systems with "hard"
6903afa2 414dynamic linking, like C<AIX> and C<OS/2>. It is a bug of C<Berkeley DB>
be771a83 415which is left unnoticed if C<DB> uses I<forgiving> system malloc().
a0d0e21e 416
aa689395
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417=item Bad hash
418
419(P) One of the internal hash routines was passed a null HV pointer.
420
6df41af2
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421=item Badly placed ()'s
422
423(A) You've accidentally run your script through B<csh> instead
424of Perl. Check the #! line, or manually feed your script into
425Perl yourself.
426
a7cb8dae 427=item Bad name after %s
a0d0e21e 428
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429(F) You started to name a symbol by using a package prefix, and then
430didn't finish the symbol. In particular, you can't interpolate outside
431of quotes, so
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432
433 $var = 'myvar';
434 $sym = mypack::$var;
435
436is not the same as
437
438 $var = 'myvar';
439 $sym = "mypack::$var";
440
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441=item Bad plugin affecting keyword '%s'
442
443(F) An extension using the keyword plugin mechanism violated the
444plugin API.
445
4ad56ec9
IZ
446=item Bad realloc() ignored
447
6903afa2
FC
448(S malloc) An internal routine called realloc() on something that
449had never been malloc()ed in the first place. Mandatory, but can
450be disabled by setting the environment variable C<PERL_BADFREE> to 1.
4ad56ec9 451
a0d0e21e
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452=item Bad symbol for array
453
454(P) An internal request asked to add an array entry to something that
455wasn't a symbol table entry.
456
4df3f177
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457=item Bad symbol for dirhandle
458
459(P) An internal request asked to add a dirhandle entry to something
460that wasn't a symbol table entry.
461
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462=item Bad symbol for filehandle
463
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464(P) An internal request asked to add a filehandle entry to something
465that wasn't a symbol table entry.
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466
467=item Bad symbol for hash
468
469(P) An internal request asked to add a hash entry to something that
470wasn't a symbol table entry.
471
34d09196
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472=item Bareword found in conditional
473
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474(W bareword) The compiler found a bareword where it expected a
475conditional, which often indicates that an || or && was parsed as part
476of the last argument of the previous construct, for example:
34d09196
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477
478 open FOO || die;
479
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480It may also indicate a misspelled constant that has been interpreted as
481a bareword:
34d09196
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482
483 use constant TYPO => 1;
484 if (TYOP) { print "foo" }
485
486The C<strict> pragma is useful in avoiding such errors.
487
6df41af2
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488=item Bareword "%s" not allowed while "strict subs" in use
489
490(F) With "strict subs" in use, a bareword is only allowed as a
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491subroutine identifier, in curly brackets or to the left of the "=>"
492symbol. Perhaps you need to predeclare a subroutine?
6df41af2
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493
494=item Bareword "%s" refers to nonexistent package
495
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496(W bareword) You used a qualified bareword of the form C<Foo::>, but the
497compiler saw no other uses of that namespace before that point. Perhaps
498you need to predeclare a package?
6df41af2 499
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500=item BEGIN failed--compilation aborted
501
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502(F) An untrapped exception was raised while executing a BEGIN
503subroutine. Compilation stops immediately and the interpreter is
504exited.
a0d0e21e 505
68dc0745
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506=item BEGIN not safe after errors--compilation aborted
507
508(F) Perl found a C<BEGIN {}> subroutine (or a C<use> directive, which
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509implies a C<BEGIN {}>) after one or more compilation errors had already
510occurred. Since the intended environment for the C<BEGIN {}> could not
511be guaranteed (due to the errors), and since subsequent code likely
512depends on its correct operation, Perl just gave up.
68dc0745 513
c782d7ee 514=item \%d better written as $%d
6df41af2 515
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516(W syntax) Outside of patterns, backreferences live on as variables.
517The use of backslashes is grandfathered on the right-hand side of a
518substitution, but stylistically it's better to use the variable form
519because other Perl programmers will expect it, and it works better if
520there are more than 9 backreferences.
6df41af2 521
252aa082
JH
522=item Binary number > 0b11111111111111111111111111111111 non-portable
523
e476b1b5 524(W portable) The binary number you specified is larger than 2**32-1
9e24b6e2
JH
525(4294967295) and therefore non-portable between systems. See
526L<perlport> for more on portability concerns.
252aa082 527
69282e91 528=item bind() on closed socket %s
a0d0e21e 529
be771a83
GS
530(W closed) You tried to do a bind on a closed socket. Did you forget to
531check the return value of your socket() call? See L<perlfunc/bind>.
a0d0e21e 532
c289d2f7
JH
533=item binmode() on closed filehandle %s
534
535(W unopened) You tried binmode() on a filehandle that was never opened.
4dcecea4 536Check your control flow and number of arguments.
c289d2f7 537
c5a0f51a
JH
538=item Bit vector size > 32 non-portable
539
e476b1b5 540(W portable) Using bit vector sizes larger than 32 is non-portable.
c5a0f51a 541
043c750c 542=item Bizarre copy of %s
4633a7c4 543
be771a83 544(P) Perl detected an attempt to copy an internal value that is not
ab830aa0 545copiable.
4633a7c4 546
5a25739d
FC
547=item Bizarre SvTYPE [%d]
548
434f489b 549(P) When starting a new thread or returning values from a thread, Perl
5a25739d
FC
550encountered an invalid data type.
551
f675dbe5
CB
552=item Buffer overflow in prime_env_iter: %s
553
be771a83
GS
554(W internal) A warning peculiar to VMS. While Perl was preparing to
555iterate over %ENV, it encountered a logical name or symbol definition
556which was too long, so it was truncated to the string shown.
f675dbe5 557
a0d0e21e
LW
558=item Callback called exit
559
4929bf7b 560(F) A subroutine invoked from an external package via call_sv()
a0d0e21e
LW
561exited by calling exit.
562
6df41af2 563=item %s() called too early to check prototype
f675dbe5 564
be771a83
GS
565(W prototype) You've called a function that has a prototype before the
566parser saw a definition or declaration for it, and Perl could not check
567that the call conforms to the prototype. You need to either add an
568early prototype declaration for the subroutine in question, or move the
569subroutine definition ahead of the call to get proper prototype
570checking. Alternatively, if you are certain that you're calling the
571function correctly, you may put an ampersand before the name to avoid
572the warning. See L<perlsub>.
f675dbe5 573
56feebad
FC
574=item Calling POSIX::%s() is deprecated
575
576(D deprecated) You called a function whose use is deprecated. See
577the function's name in L<POSIX> for details.
578
0c7df902
JH
579=item Cannot chr %f
580
581(F) You passed an invalid number (like an infinity or not-a-number) to C<chr>.
582
5dee29d4 583=item Cannot compress %f in pack
0c7df902 584
5dee29d4
JH
585(F) You tried compressing an infinity or not-a-number as an unsigned
586integer with BER, which makes no sense.
0c7df902 587
49704364 588=item Cannot compress integer in pack
0258719b 589
717feafc
JH
590(F) An argument to pack("w",...) was too large to compress.
591The BER compressed integer format can only be used with positive
592integers, and you attempted to compress a very large number (> 1e308).
593See L<perlfunc/pack>.
0258719b 594
49704364 595=item Cannot compress negative numbers in pack
0258719b
NC
596
597(F) An argument to pack("w",...) was negative. The BER compressed integer
598format can only be used with positive integers. See L<perlfunc/pack>.
599
5c1f4d79
NC
600=item Cannot convert a reference to %s to typeglob
601
6903afa2
FC
602(F) You manipulated Perl's symbol table directly, stored a reference
603in it, then tried to access that symbol via conventional Perl syntax.
604The access triggers Perl to autovivify that typeglob, but it there is
605no legal conversion from that type of reference to a typeglob.
5c1f4d79 606
4040665a 607=item Cannot copy to %s
ba2fdce6
NC
608
609(P) Perl detected an attempt to copy a value to an internal type that cannot
4dcecea4 610be directly assigned to.
ba2fdce6 611
b5d97229
RGS
612=item Cannot find encoding "%s"
613
614(S io) You tried to apply an encoding that did not exist to a filehandle,
615either with open() or binmode().
616
0c7df902
JH
617=item Cannot pack %f with '%c'
618
5dee29d4 619(F) You tried converting an infinity or not-a-number to an integer,
0c7df902
JH
620which makes no sense.
621
622=item Cannot printf %f with '%c'
623
624(F) You tried printing an infinity or not-a-number as a character (%c),
625which makes no sense. Maybe you meant '%s', or just stringifying it?
626
7355df7e
FC
627=item Cannot set tied @DB::args
628
629(F) C<caller> tried to set C<@DB::args>, but found it tied. Tying C<@DB::args>
630is not supported. (Before this error was added, it used to crash.)
631
ce65bc73
FC
632=item Cannot tie unreifiable array
633
634(P) You somehow managed to call C<tie> on an array that does not
635keep a reference count on its arguments and cannot be made to
636do so. Such arrays are not even supposed to be accessible to
637Perl code, but are only used internally.
638
96ebfdd7
RK
639=item Can only compress unsigned integers in pack
640
641(F) An argument to pack("w",...) was not an integer. The BER compressed
642integer format can only be used with positive integers, and you attempted
643to compress something else. See L<perlfunc/pack>.
644
a0d0e21e
LW
645=item Can't bless non-reference value
646
647(F) Only hard references may be blessed. This is how Perl "enforces"
648encapsulation of objects. See L<perlobj>.
649
dc57907a
RGS
650=item Can't "break" in a loop topicalizer
651
0d863452 652(F) You called C<break>, but you're in a C<foreach> block rather than
6903afa2 653a C<given> block. You probably meant to use C<next> or C<last>.
0d863452
RH
654
655=item Can't "break" outside a given block
dc57907a 656
0d863452
RH
657(F) You called C<break>, but you're not inside a C<given> block.
658
6df41af2
GS
659=item Can't call method "%s" on an undefined value
660
661(F) You used the syntax of a method call, but the slot filled by the
be771a83
GS
662object reference or package name contains an undefined value. Something
663like this will reproduce the error:
6df41af2
GS
664
665 $BADREF = undef;
666 process $BADREF 1,2,3;
667 $BADREF->process(1,2,3);
668
a0d0e21e
LW
669=item Can't call method "%s" on unblessed reference
670
54310121 671(F) A method call must know in what package it's supposed to run. It
be771a83
GS
672ordinarily finds this out from the object reference you supply, but you
673didn't supply an object reference in this case. A reference isn't an
674object reference until it has been blessed. See L<perlobj>.
a0d0e21e
LW
675
676=item Can't call method "%s" without a package or object reference
677
678(F) You used the syntax of a method call, but the slot filled by the
be771a83
GS
679object reference or package name contains an expression that returns a
680defined value which is neither an object reference nor a package name.
72b5445b
GS
681Something like this will reproduce the error:
682
683 $BADREF = 42;
684 process $BADREF 1,2,3;
685 $BADREF->process(1,2,3);
686
dfe378f1
FC
687=item Can't call mro_isa_changed_in() on anonymous symbol table
688
689(P) Perl got confused as to whether a hash was a plain hash or a
690symbol table hash when trying to update @ISA caches.
691
2bf7e7b2
FC
692=item Can't call mro_method_changed_in() on anonymous symbol table
693
694(F) An XS module tried to call C<mro_method_changed_in> on a hash that was
695not attached to the symbol table.
696
a0d0e21e
LW
697=item Can't chdir to %s
698
f703fc96 699(F) You called C<perl -x/foo/bar>, but F</foo/bar> is not a directory
a0d0e21e
LW
700that you can chdir to, possibly because it doesn't exist.
701
0545a864 702=item Can't check filesystem of script "%s" for nosuid
104d25b7 703
be771a83
GS
704(P) For some reason you can't check the filesystem of the script for
705nosuid.
104d25b7 706
22e74366 707=item Can't coerce %s to %s in %s
a0d0e21e
LW
708
709(F) Certain types of SVs, in particular real symbol table entries
55497cff 710(typeglobs), can't be forced to stop being what they are. So you can't
a0d0e21e
LW
711say things like:
712
713 *foo += 1;
714
715You CAN say
716
717 $foo = *foo;
718 $foo += 1;
719
720but then $foo no longer contains a glob.
721
0d863452 722=item Can't "continue" outside a when block
dc57907a 723
0d863452
RH
724(F) You called C<continue>, but you're not inside a C<when>
725or C<default> block.
726
a0d0e21e
LW
727=item Can't create pipe mailbox
728
be771a83
GS
729(P) An error peculiar to VMS. The process is suffering from exhausted
730quotas or other plumbing problems.
a0d0e21e 731
eb64745e
GS
732=item Can't declare %s in "%s"
733
30c282f6
NC
734(F) Only scalar, array, and hash variables may be declared as "my", "our" or
735"state" variables. They must have ordinary identifiers as names.
a0d0e21e 736
fc7debfb
FC
737=item Can't "default" outside a topicalizer
738
739(F) You have used a C<default> block that is neither inside a
740C<foreach> loop nor a C<given> block. (Note that this error is
741issued on exit from the C<default> block, so you won't get the
742error if you use an explicit C<continue>.)
743
ab0b796c
KW
744=item Can't do %s("%s") on non-UTF-8 locale; resolved to "%s".
745
746(W locale) You are 1) running under "C<use locale>"; 2) the current
747locale is not a UTF-8 one; 3) you tried to do the designated case-change
748operation on the specified Unicode character; and 4) the result of this
749operation would mix Unicode and locale rules, which likely conflict.
750Mixing of different rule types is forbidden, so the operation was not
751done; instead the result is the indicated value, which is the best
752available that uses entirely Unicode rules. That turns out to almost
753always be the original character, unchanged.
754
755It is generally a bad idea to mix non-UTF-8 locales and Unicode, and
756this issue is one of the reasons why. This warning is raised when
757Unicode rules would normally cause the result of this operation to
758contain a character that is in the range specified by the locale,
7590..255, and hence is subject to the locale's rules, not Unicode's.
760
761If you are using locale purely for its characteristics related to things
762like its numeric and time formatting (and not C<LC_CTYPE>), consider
763using a restricted form of the locale pragma (see L<perllocale/The "use
764locale" pragma>) like "S<C<use locale ':not_characters'>>".
765
766Note that failed case-changing operations done as a result of
767case-insensitive C</i> regular expression matching will show up in this
768warning as having the C<fc> operation (as that is what the regular
769expression engine calls behind the scenes.)
770
6df41af2
GS
771=item Can't do inplace edit: %s is not a regular file
772
be771a83 773(S inplace) You tried to use the B<-i> switch on a special file, such as
df7075a8 774a file in /dev, a FIFO or an uneditable directory. The file was ignored.
6df41af2 775
a0d0e21e
LW
776=item Can't do inplace edit on %s: %s
777
be771a83
GS
778(S inplace) The creation of the new file failed for the indicated
779reason.
a0d0e21e 780
54310121 781=item Can't do inplace edit without backup
a0d0e21e 782
be771a83
GS
783(F) You're on a system such as MS-DOS that gets confused if you try
784reading from a deleted (but still opened) file. You have to say
785C<-i.bak>, or some such.
a0d0e21e 786
10f9c03d 787=item Can't do inplace edit: %s would not be unique
a0d0e21e 788
e476b1b5 789(S inplace) Your filesystem does not support filenames longer than 14
10f9c03d
CK
790characters and Perl was unable to create a unique filename during
791inplace editing with the B<-i> switch. The file was ignored.
a0d0e21e 792
a0d0e21e
LW
793=item Can't do waitpid with flags
794
be771a83
GS
795(F) This machine doesn't have either waitpid() or wait4(), so only
796waitpid() without flags is emulated.
a0d0e21e 797
a0d0e21e
LW
798=item Can't emulate -%s on #! line
799
be771a83
GS
800(F) The #! line specifies a switch that doesn't make sense at this
801point. For example, it'd be kind of silly to put a B<-x> on the #!
802line.
a0d0e21e 803
1109a392
MHM
804=item Can't %s %s-endian %ss on this platform
805
806(F) Your platform's byte-order is neither big-endian nor little-endian,
807or it has a very strange pointer size. Packing and unpacking big- or
808little-endian floating point values and pointers may not be possible.
809See L<perlfunc/pack>.
810
a0d0e21e
LW
811=item Can't exec "%s": %s
812
d1be9408 813(W exec) A system(), exec(), or piped open call could not execute the
be771a83
GS
814named program for the indicated reason. Typical reasons include: the
815permissions were wrong on the file, the file wasn't found in
816C<$ENV{PATH}>, the executable in question was compiled for another
817architecture, or the #! line in a script points to an interpreter that
818can't be run for similar reasons. (Or maybe your system doesn't support
819#! at all.)
a0d0e21e
LW
820
821=item Can't exec %s
822
be771a83
GS
823(F) Perl was trying to execute the indicated program for you because
824that's what the #! line said. If that's not what you wanted, you may
825need to mention "perl" on the #! line somewhere.
a0d0e21e
LW
826
827=item Can't execute %s
828
be771a83
GS
829(F) You used the B<-S> switch, but the copies of the script to execute
830found in the PATH did not have correct permissions.
2a92aaa0 831
6df41af2 832=item Can't find an opnumber for "%s"
2a92aaa0 833
be771a83
GS
834(F) A string of a form C<CORE::word> was given to prototype(), but there
835is no builtin with the name C<word>.
6df41af2 836
56ca2fc0
JH
837=item Can't find %s character property "%s"
838
839(F) You used C<\p{}> or C<\P{}> but the character property by that name
6903afa2 840could not be found. Maybe you misspelled the name of the property?
e1b711da 841See L<perluniprops/Properties accessible through \p{} and \P{}>
9b73678d 842for a complete list of available official properties.
56ca2fc0 843
6df41af2
GS
844=item Can't find label %s
845
be771a83
GS
846(F) You said to goto a label that isn't mentioned anywhere that it's
847possible for us to go to. See L<perlfunc/goto>.
2a92aaa0
GS
848
849=item Can't find %s on PATH
850
be771a83
GS
851(F) You used the B<-S> switch, but the script to execute could not be
852found in the PATH.
a0d0e21e 853
6df41af2 854=item Can't find %s on PATH, '.' not in PATH
a0d0e21e 855
be771a83
GS
856(F) You used the B<-S> switch, but the script to execute could not be
857found in the PATH, or at least not with the correct permissions. The
858script exists in the current directory, but PATH prohibits running it.
a0d0e21e
LW
859
860=item Can't find string terminator %s anywhere before EOF
861
be771a83
GS
862(F) Perl strings can stretch over multiple lines. This message means
863that the closing delimiter was omitted. Because bracketed quotes count
864nesting levels, the following is missing its final parenthesis:
a0d0e21e 865
fb73857a
PP
866 print q(The character '(' starts a side comment.);
867
97b3d10f 868If you're getting this error from a here-document, you may have
b6b8cb97
FC
869included unseen whitespace before or after your closing tag or there
870may not be a linebreak after it. A good programmer's editor will have
871a way to help you find these characters (or lack of characters). See
872L<perlop> for the full details on here-documents.
a0d0e21e 873
660a4616
ST
874=item Can't find Unicode property definition "%s"
875
5f8ad6b6
FC
876(F) You may have tried to use C<\p> which means a Unicode
877property (for example C<\p{Lu}> matches all uppercase
fa816bf3 878letters). If you did mean to use a Unicode property, see
e1b711da 879L<perluniprops/Properties accessible through \p{} and \P{}>
6903afa2 880for a complete list of available properties. If you didn't
fa816bf3
FC
881mean to use a Unicode property, escape the C<\p>, either by
882C<\\p> (just the C<\p>) or by C<\Q\p> (the rest of the string, or
5f8ad6b6 883until C<\E>).
660a4616 884
b3647a36 885=item Can't fork: %s
a0d0e21e 886
be771a83
GS
887(F) A fatal error occurred while trying to fork while opening a
888pipeline.
a0d0e21e 889
b3647a36
SR
890=item Can't fork, trying again in 5 seconds
891
c973c02e 892(W pipe) A fork in a piped open failed with EAGAIN and will be retried
b3647a36
SR
893after five seconds.
894
748a9306
LW
895=item Can't get filespec - stale stat buffer?
896
be771a83
GS
897(S) A warning peculiar to VMS. This arises because of the difference
898between access checks under VMS and under the Unix model Perl assumes.
899Under VMS, access checks are done by filename, rather than by bits in
900the stat buffer, so that ACLs and other protections can be taken into
901account. Unfortunately, Perl assumes that the stat buffer contains all
902the necessary information, and passes it, instead of the filespec, to
2fe2bdfd 903the access-checking routine. It will try to retrieve the filespec using
be771a83
GS
904the device name and FID present in the stat buffer, but this works only
905if you haven't made a subsequent call to the CRTL stat() routine,
906because the device name is overwritten with each call. If this warning
2fe2bdfd
FC
907appears, the name lookup failed, and the access-checking routine gave up
908and returned FALSE, just to be conservative. (Note: The access-checking
be771a83
GS
909routine knows about the Perl C<stat> operator and file tests, so you
910shouldn't ever see this warning in response to a Perl command; it arises
911only if some internal code takes stat buffers lightly.)
748a9306 912
a0d0e21e
LW
913=item Can't get pipe mailbox device name
914
be771a83
GS
915(P) An error peculiar to VMS. After creating a mailbox to act as a
916pipe, Perl can't retrieve its name for later use.
a0d0e21e
LW
917
918=item Can't get SYSGEN parameter value for MAXBUF
919
748a9306
LW
920(P) An error peculiar to VMS. Perl asked $GETSYI how big you want your
921mailbox buffers to be, and didn't get an answer.
a0d0e21e 922
6df41af2 923=item Can't "goto" into the middle of a foreach loop
a0d0e21e 924
be771a83
GS
925(F) A "goto" statement was executed to jump into the middle of a foreach
926loop. You can't get there from here. See L<perlfunc/goto>.
6df41af2
GS
927
928=item Can't "goto" out of a pseudo block
929
be771a83
GS
930(F) A "goto" statement was executed to jump out of what might look like
931a block, except that it isn't a proper block. This usually occurs if
932you tried to jump out of a sort() block or subroutine, which is a no-no.
933See L<perlfunc/goto>.
a0d0e21e 934
5a25739d
FC
935=item Can't goto subroutine from an eval-%s
936
937(F) The "goto subroutine" call can't be used to jump out of an eval
938"string" or block.
939
9850bf21 940=item Can't goto subroutine from a sort sub (or similar callback)
cd299c6e 941
9850bf21
RH
942(F) The "goto subroutine" call can't be used to jump out of the
943comparison sub for a sort(), or from a similar callback (such
944as the reduce() function in List::Util).
945
6df41af2
GS
946=item Can't goto subroutine outside a subroutine
947
be771a83
GS
948(F) The deeply magical "goto subroutine" call can only replace one
949subroutine call for another. It can't manufacture one out of whole
950cloth. In general you should be calling it out of only an AUTOLOAD
951routine anyway. See L<perlfunc/goto>.
6df41af2 952
0b5b802d
GS
953=item Can't ignore signal CHLD, forcing to default
954
be771a83
GS
955(W signal) Perl has detected that it is being run with the SIGCHLD
956signal (sometimes known as SIGCLD) disabled. Since disabling this
957signal will interfere with proper determination of exit status of child
958processes, Perl has reset the signal to its default value. This
959situation typically indicates that the parent program under which Perl
960may be running (e.g. cron) is being very careless.
0b5b802d 961
e2c0f81f
DG
962=item Can't kill a non-numeric process ID
963
964(F) Process identifiers must be (signed) integers. It is a fatal error to
965attempt to kill() an undefined, empty-string or otherwise non-numeric
966process identifier.
967
6df41af2 968=item Can't "last" outside a loop block
4633a7c4 969
6df41af2 970(F) A "last" statement was executed to break out of the current block,
be771a83
GS
971except that there's this itty bitty problem called there isn't a current
972block. Note that an "if" or "else" block doesn't count as a "loopish"
973block, as doesn't a block given to sort(), map() or grep(). You can
974usually double the curlies to get the same effect though, because the
975inner curlies will be considered a block that loops once. See
976L<perlfunc/last>.
4633a7c4 977
2c7d6b9c
RGS
978=item Can't linearize anonymous symbol table
979
980(F) Perl tried to calculate the method resolution order (MRO) of a
981package, but failed because the package stash has no name.
982
b8170e59
JB
983=item Can't load '%s' for module %s
984
6903afa2
FC
985(F) The module you tried to load failed to load a dynamic extension.
986This may either mean that you upgraded your version of perl to one
987that is incompatible with your old dynamic extensions (which is known
988to happen between major versions of perl), or (more likely) that your
989dynamic extension was built against an older version of the library
990that is installed on your system. You may need to rebuild your old
991dynamic extensions.
b8170e59 992
748a9306
LW
993=item Can't localize lexical variable %s
994
2ba9eb46 995(F) You used local on a variable name that was previously declared as a
b7e4ecc1
FC
996lexical variable using "my" or "state". This is not allowed. If you
997want to localize a package variable of the same name, qualify it with
998the package name.
748a9306 999
6df41af2 1000=item Can't localize through a reference
4727527e 1001
6df41af2
GS
1002(F) You said something like C<local $$ref>, which Perl can't currently
1003handle, because when it goes to restore the old value of whatever $ref
be771a83 1004pointed to after the scope of the local() is finished, it can't be sure
64977eb6 1005that $ref will still be a reference.
4727527e 1006
ea071790 1007=item Can't locate %s
ec889f3a 1008
fa816bf3
FC
1009(F) You said to C<do> (or C<require>, or C<use>) a file that couldn't be found.
1010Perl looks for the file in all the locations mentioned in @INC, unless
1011the file name included the full path to the file. Perhaps you need
1012to set the PERL5LIB or PERL5OPT environment variable to say where the
1013extra library is, or maybe the script needs to add the library name
be771a83
GS
1014to @INC. Or maybe you just misspelled the name of the file. See
1015L<perlfunc/require> and L<lib>.
a0d0e21e 1016
6df41af2
GS
1017=item Can't locate auto/%s.al in @INC
1018
be771a83
GS
1019(F) A function (or method) was called in a package which allows
1020autoload, but there is no function to autoload. Most probable causes
1021are a misprint in a function/method name or a failure to C<AutoSplit>
1022the file, say, by doing C<make install>.
6df41af2 1023
b8170e59
JB
1024=item Can't locate loadable object for module %s in @INC
1025
1026(F) The module you loaded is trying to load an external library, like
d70d8e57 1027for example, F<foo.so> or F<bar.dll>, but the L<DynaLoader> module was
b8170e59
JB
1028unable to locate this library. See L<DynaLoader>.
1029
a0d0e21e
LW
1030=item Can't locate object method "%s" via package "%s"
1031
1032(F) You called a method correctly, and it correctly indicated a package
1033functioning as a class, but that package doesn't define that particular
2ba9eb46 1034method, nor does any of its base classes. See L<perlobj>.
a0d0e21e 1035
8af56b9d
FC
1036=item Can't locate object method "%s" via package "%s" (perhaps you forgot
1037to load "%s"?)
1038
1039(F) You called a method on a class that did not exist, and the method
1040could not be found in UNIVERSAL. This often means that a method
1041requires a package that has not been loaded.
1042
a0d0e21e
LW
1043=item Can't locate package %s for @%s::ISA
1044
be771a83
GS
1045(W syntax) The @ISA array contained the name of another package that
1046doesn't seem to exist.
a0d0e21e 1047
2f7da168
RK
1048=item Can't locate PerlIO%s
1049
1050(F) You tried to use in open() a PerlIO layer that does not exist,
1051e.g. open(FH, ">:nosuchlayer", "somefile").
1052
f4ad53f4 1053=item Can't make list assignment to %ENV on this system
3e3baf6d 1054
be771a83
GS
1055(F) List assignment to %ENV is not supported on some systems, notably
1056VMS.
3e3baf6d 1057
cd40cd58
NC
1058=item Can't make loaded symbols global on this platform while loading %s
1059
ff9c1ae8 1060(S) A module passed the flag 0x01 to DynaLoader::dl_load_file() to request
cd40cd58
NC
1061that symbols from the stated file are made available globally within the
1062process, but that functionality is not available on this platform. Whilst
1063the module likely will still work, this may prevent the perl interpreter
1064from loading other XS-based extensions which need to link directly to
1065functions defined in the C or XS code in the stated file.
1066
a0d0e21e
LW
1067=item Can't modify %s in %s
1068
be771a83
GS
1069(F) You aren't allowed to assign to the item indicated, or otherwise try
1070to change it, such as with an auto-increment.
a0d0e21e 1071
54310121 1072=item Can't modify nonexistent substring
a0d0e21e
LW
1073
1074(P) The internal routine that does assignment to a substr() was handed
1075a NULL.
1076
6df41af2
GS
1077=item Can't modify non-lvalue subroutine call
1078
1079(F) Subroutines meant to be used in lvalue context should be declared as
2fe2bdfd 1080such. See L<perlsub/"Lvalue subroutines">.
6df41af2 1081
cf6e1fa1
FC
1082=item Can't modify reference to %s in %s assignment
1083
1084(F) Only a limited number of constructs can be used as the argument to a
1085reference constructor on the left-hand side of an assignment, and what
1086you used was not one of them. See L<perlref/Assigning to References>.
1087
1088=item Can't modify reference to localized parenthesized array in list
1089assignment
1090
1091(F) Assigning to C<\local(@array)> or C<\(local @array)> is not supported, as
1092it is not clear exactly what it should do. If you meant to make @array
1093refer to some other array, use C<\@array = \@other_array>. If you want to
1094make the elements of @array aliases of the scalars referenced on the
1095right-hand side, use C<\(@array) = @scalar_refs>.
1096
1097=item Can't modify reference to parenthesized hash in list assignment
1098
1099(F) Assigning to C<\(%hash)> is not supported. If you meant to make %hash
1100refer to some other hash, use C<\%hash = \%other_hash>. If you want to
1101make the elements of %hash into aliases of the scalars referenced on the
1102right-hand side, use a hash slice: C<\@hash{@keys} = @those_scalar_refs>.
1103
5f05dabc 1104=item Can't msgrcv to read-only var
a0d0e21e 1105
5f05dabc 1106(F) The target of a msgrcv must be modifiable to be used as a receive
a0d0e21e
LW
1107buffer.
1108
6df41af2
GS
1109=item Can't "next" outside a loop block
1110
1111(F) A "next" statement was executed to reiterate the current block, but
1112there isn't a current block. Note that an "if" or "else" block doesn't
be771a83
GS
1113count as a "loopish" block, as doesn't a block given to sort(), map() or
1114grep(). You can usually double the curlies to get the same effect
1115though, because the inner curlies will be considered a block that loops
1116once. See L<perlfunc/next>.
6df41af2 1117
a0d0e21e
LW
1118=item Can't open %s: %s
1119
c47ff5f1 1120(S inplace) The implicit opening of a file through use of the C<< <> >>
08e9d68e 1121filehandle, either implicitly under the C<-n> or C<-p> command-line
46fa9b26
FC
1122switches, or explicitly, failed for the indicated reason. Usually
1123this is because you don't have read permission for a file which
1124you named on the command line.
1125
1126(F) You tried to call perl with the B<-e> switch, but F</dev/null> (or
1127your operating system's equivalent) could not be opened.
a0d0e21e 1128
9a869a14
RGS
1129=item Can't open a reference
1130
1131(W io) You tried to open a scalar reference for reading or writing,
2fe2bdfd 1132using the 3-arg open() syntax:
9a869a14
RGS
1133
1134 open FH, '>', $ref;
1135
1136but your version of perl is compiled without perlio, and this form of
1137open is not supported.
1138
a0d0e21e
LW
1139=item Can't open bidirectional pipe
1140
be771a83
GS
1141(W pipe) You tried to say C<open(CMD, "|cmd|")>, which is not supported.
1142You can try any of several modules in the Perl library to do this, such
1143as IPC::Open2. Alternately, direct the pipe's output to a file using
1144">", and then read it in under a different file handle.
a0d0e21e 1145
748a9306
LW
1146=item Can't open error file %s as stderr
1147
be771a83
GS
1148(F) An error peculiar to VMS. Perl does its own command line
1149redirection, and couldn't open the file specified after '2>' or '2>>' on
1150the command line for writing.
748a9306
LW
1151
1152=item Can't open input file %s as stdin
1153
be771a83
GS
1154(F) An error peculiar to VMS. Perl does its own command line
1155redirection, and couldn't open the file specified after '<' on the
1156command line for reading.
748a9306
LW
1157
1158=item Can't open output file %s as stdout
1159
be771a83
GS
1160(F) An error peculiar to VMS. Perl does its own command line
1161redirection, and couldn't open the file specified after '>' or '>>' on
1162the command line for writing.
748a9306
LW
1163
1164=item Can't open output pipe (name: %s)
1165
be771a83
GS
1166(P) An error peculiar to VMS. Perl does its own command line
1167redirection, and couldn't open the pipe into which to send data destined
1168for stdout.
748a9306 1169
3b1cf97d 1170=item Can't open perl script "%s": %s
a0d0e21e
LW
1171
1172(F) The script you specified can't be opened for the indicated reason.
1173
fa3aa65a
JC
1174If you're debugging a script that uses #!, and normally relies on the
1175shell's $PATH search, the -S option causes perl to do that search, so
1176you don't have to type the path or C<`which $scriptname`>.
1177
6df41af2
GS
1178=item Can't read CRTL environ
1179
1180(S) A warning peculiar to VMS. Perl tried to read an element of %ENV
1181from the CRTL's internal environment array and discovered the array was
1182missing. You need to figure out where your CRTL misplaced its environ
be771a83
GS
1183or define F<PERL_ENV_TABLES> (see L<perlvms>) so that environ is not
1184searched.
6df41af2 1185
6df41af2
GS
1186=item Can't "redo" outside a loop block
1187
1188(F) A "redo" statement was executed to restart the current block, but
1189there isn't a current block. Note that an "if" or "else" block doesn't
1190count as a "loopish" block, as doesn't a block given to sort(), map()
1191or grep(). You can usually double the curlies to get the same effect
1192though, because the inner curlies will be considered a block that
1193loops once. See L<perlfunc/redo>.
1194
64977eb6 1195=item Can't remove %s: %s, skipping file
10f9c03d 1196
be771a83
GS
1197(S inplace) You requested an inplace edit without creating a backup
1198file. Perl was unable to remove the original file to replace it with
1199the modified file. The file was left unmodified.
10f9c03d 1200
a0d0e21e
LW
1201=item Can't rename %s to %s: %s, skipping file
1202
e476b1b5 1203(S inplace) The rename done by the B<-i> switch failed for some reason,
10f9c03d 1204probably because you don't have write permission to the directory.
a0d0e21e 1205
748a9306
LW
1206=item Can't reopen input pipe (name: %s) in binary mode
1207
be771a83
GS
1208(P) An error peculiar to VMS. Perl thought stdin was a pipe, and tried
1209to reopen it to accept binary data. Alas, it failed.
748a9306 1210
9415f659
KW
1211=item Can't represent character for Ox%X on this platform
1212
1213(F) There is a hard limit to how big a character code point can be due
1214to the fundamental properties of UTF-8, especially on EBCDIC
1215platforms. The given code point exceeds that. The only work-around is
1216to not use such a large code point.
1217
4f12ec0e
FC
1218=item Can't reset %ENV on this system
1219
1220(F) You called C<reset('E')> or similar, which tried to reset
1221all variables in the current package beginning with "E". In
1222the main package, that includes %ENV. Resetting %ENV is not
1223supported on some systems, notably VMS.
1224
fe13d51d 1225=item Can't resolve method "%s" overloading "%s" in package "%s"
6df41af2 1226
1fa582fa
FC
1227(F)(P) Error resolving overloading specified by a method name (as
1228opposed to a subroutine reference): no such method callable via the
1229package. If the method name is C<???>, this is an internal error.
6df41af2 1230
cd06dffe
GS
1231=item Can't return %s from lvalue subroutine
1232
be771a83
GS
1233(F) Perl detected an attempt to return illegal lvalues (such as
1234temporary or readonly values) from a subroutine used as an lvalue. This
1235is not allowed.
cd06dffe 1236
96ebfdd7
RK
1237=item Can't return outside a subroutine
1238
1239(F) The return statement was executed in mainline code, that is, where
1240there was no subroutine call to return out of. See L<perlsub>.
1241
78f9721b
SM
1242=item Can't return %s to lvalue scalar context
1243
6903afa2
FC
1244(F) You tried to return a complete array or hash from an lvalue
1245subroutine, but you called the subroutine in a way that made Perl
1246think you meant to return only one value. You probably meant to
1247write parentheses around the call to the subroutine, which tell
1248Perl that the call should be in list context.
78f9721b 1249
a0d0e21e
LW
1250=item Can't stat script "%s"
1251
be771a83
GS
1252(P) For some reason you can't fstat() the script even though you have it
1253open already. Bizarre.
a0d0e21e 1254
a0d0e21e
LW
1255=item Can't take log of %g
1256
fb73857a 1257(F) For ordinary real numbers, you can't take the logarithm of a
6903afa2 1258negative number or zero. There's a Math::Complex package that comes
be771a83
GS
1259standard with Perl, though, if you really want to do that for the
1260negative numbers.
a0d0e21e
LW
1261
1262=item Can't take sqrt of %g
1263
1264(F) For ordinary real numbers, you can't take the square root of a
fb73857a
PP
1265negative number. There's a Math::Complex package that comes standard
1266with Perl, though, if you really want to do that.
a0d0e21e
LW
1267
1268=item Can't undef active subroutine
1269
1270(F) You can't undefine a routine that's currently running. You can,
1271however, redefine it while it's running, and you can even undef the
1272redefined subroutine while the old routine is running. Go figure.
1273
c81225bc 1274=item Can't upgrade %s (%d) to %d
a0d0e21e 1275
be771a83
GS
1276(P) The internal sv_upgrade routine adds "members" to an SV, making it
1277into a more specialized kind of SV. The top several SV types are so
1278specialized, however, that they cannot be interconverted. This message
1279indicates that such a conversion was attempted.
a0d0e21e 1280
6651ba0b
FC
1281=item Can't use '%c' after -mname
1282
1283(F) You tried to call perl with the B<-m> switch, but you put something
1284other than "=" after the module name.
1285
1f1ec7b5
KW
1286=item Can't use a hash as a reference
1287
1288(F) You tried to use a hash as a reference, as in
66a1f5ec
FC
1289C<< %foo->{"bar"} >> or C<< %$ref->{"hello"} >>. Versions of perl
1290<= 5.22.0 used to allow this syntax, but shouldn't
1291have. This was deprecated in perl 5.6.1.
1f1ec7b5
KW
1292
1293=item Can't use an array as a reference
1294
1295(F) You tried to use an array as a reference, as in
66a1f5ec
FC
1296C<< @foo->[23] >> or C<< @$ref->[99] >>. Versions of perl <= 5.22.0
1297used to allow this syntax, but shouldn't have. This
1298was deprecated in perl 5.6.1.
1f1ec7b5 1299
1db89ea5
BS
1300=item Can't use anonymous symbol table for method lookup
1301
e27ad1f2 1302(F) The internal routine that does method lookup was handed a symbol
1db89ea5
BS
1303table that doesn't have a name. Symbol tables can become anonymous
1304for example by undefining stashes: C<undef %Some::Package::>.
1305
96ebfdd7
RK
1306=item Can't use an undefined value as %s reference
1307
1308(F) A value used as either a hard reference or a symbolic reference must
1309be a defined value. This helps to delurk some insidious errors.
1310
6df41af2
GS
1311=item Can't use bareword ("%s") as %s ref while "strict refs" in use
1312
be771a83
GS
1313(F) Only hard references are allowed by "strict refs". Symbolic
1314references are disallowed. See L<perlref>.
6df41af2 1315
90b75b61 1316=item Can't use %! because Errno.pm is not available
1d2dff63 1317
20561843 1318(F) The first time the C<%!> hash is used, perl automatically loads the
6903afa2 1319Errno.pm module. The Errno module is expected to tie the %! hash to
1d2dff63
GS
1320provide symbolic names for C<$!> errno values.
1321
1109a392
MHM
1322=item Can't use both '<' and '>' after type '%c' in %s
1323
1324(F) A type cannot be forced to have both big-endian and little-endian
1325byte-order at the same time, so this combination of modifiers is not
1326allowed. See L<perlfunc/pack>.
1327
e35475de
KW
1328=item Can't use 'defined(@array)' (Maybe you should just omit the defined()?)
1329
1330(F) defined() is not useful on arrays because it
1331checks for an undefined I<scalar> value. If you want to see if the
1332array is empty, just use C<if (@array) { # not empty }> for example.
1333
1334=item Can't use 'defined(%hash)' (Maybe you should just omit the defined()?)
1335
1336(F) C<defined()> is not usually right on hashes.
1337
1338Although C<defined %hash> is false on a plain not-yet-used hash, it
1339becomes true in several non-obvious circumstances, including iterators,
1340weak references, stash names, even remaining true after C<undef %hash>.
1341These things make C<defined %hash> fairly useless in practice, so it now
1342generates a fatal error.
1343
1344If a check for non-empty is what you wanted then just put it in boolean
1345context (see L<perldata/Scalar values>):
1346
1347 if (%hash) {
1348 # not empty
1349 }
1350
1351If you had C<defined %Foo::Bar::QUUX> to check whether such a package
1352variable exists then that's never really been reliable, and isn't
1353a good way to enquire about the features of a package, or whether
1354it's loaded, etc.
1355
6df41af2
GS
1356=item Can't use %s for loop variable
1357
be771a83
GS
1358(F) Only a simple scalar variable may be used as a loop variable on a
1359foreach.
6df41af2 1360
aab6a793 1361=item Can't use global %s in "%s"
6df41af2 1362
be771a83
GS
1363(F) You tried to declare a magical variable as a lexical variable. This
1364is not allowed, because the magic can be tied to only one location
1365(namely the global variable) and it would be incredibly confusing to
1366have variables in your program that looked like magical variables but
6df41af2
GS
1367weren't.
1368
6d3b25aa
RGS
1369=item Can't use '%c' in a group with different byte-order in %s
1370
1371(F) You attempted to force a different byte-order on a type
1372that is already inside a group with a byte-order modifier.
1373For example you cannot force little-endianness on a type that
1374is inside a big-endian group.
1375
c07a80fd
PP
1376=item Can't use "my %s" in sort comparison
1377
1378(F) The global variables $a and $b are reserved for sort comparisons.
c47ff5f1 1379You mentioned $a or $b in the same line as the <=> or cmp operator,
c07a80fd
PP
1380and the variable had earlier been declared as a lexical variable.
1381Either qualify the sort variable with the package name, or rename the
1382lexical variable.
1383
a0d0e21e
LW
1384=item Can't use %s ref as %s ref
1385
1386(F) You've mixed up your reference types. You have to dereference a
1387reference of the type needed. You can use the ref() function to
1388test the type of the reference, if need be.
1389
748a9306 1390=item Can't use string ("%s") as %s ref while "strict refs" in use
a0d0e21e 1391
5e634d20
FC
1392=item Can't use string ("%s"...) as %s ref while "strict refs" in use
1393
b41bf23f
FC
1394(F) You've told Perl to dereference a string, something which
1395C<use strict> blocks to prevent it happening accidentally. See
1396L<perlref/"Symbolic references">. This can be triggered by an C<@> or C<$>
1397in a double-quoted string immediately before interpolating a variable,
1398for example in C<"user @$twitter_id">, which says to treat the contents
1399of C<$twitter_id> as an array reference; use a C<\> to have a literal C<@>
1400symbol followed by the contents of C<$twitter_id>: C<"user \@$twitter_id">.
a0d0e21e 1401
748a9306
LW
1402=item Can't use subscript on %s
1403
1404(F) The compiler tried to interpret a bracketed expression as a
1405subscript. But to the left of the brackets was an expression that
209e7cf1 1406didn't look like a hash or array reference, or anything else subscriptable.
748a9306 1407
6df41af2
GS
1408=item Can't use \%c to mean $%c in expression
1409
75b44862
GS
1410(W syntax) In an ordinary expression, backslash is a unary operator that
1411creates a reference to its argument. The use of backslash to indicate a
1412backreference to a matched substring is valid only as part of a regular
be771a83
GS
1413expression pattern. Trying to do this in ordinary Perl code produces a
1414value that prints out looking like SCALAR(0xdecaf). Use the $1 form
1415instead.
6df41af2 1416
810b8aa5
GS
1417=item Can't weaken a nonreference
1418
1419(F) You attempted to weaken something that was not a reference. Only
1420references can be weakened.
1421
fc7debfb
FC
1422=item Can't "when" outside a topicalizer
1423
1424(F) You have used a when() block that is neither inside a C<foreach>
1425loop nor a C<given> block. (Note that this error is issued on exit
1426from the C<when> block, so you won't get the error if the match fails,
1427or if you use an explicit C<continue>.)
1428
5f05dabc 1429=item Can't x= to read-only value
a0d0e21e 1430
be771a83
GS
1431(F) You tried to repeat a constant value (often the undefined value)
1432with an assignment operator, which implies modifying the value itself.
a0d0e21e
LW
1433Perhaps you need to copy the value to a temporary, and repeat that.
1434
a04e6aad 1435=item Character following "\c" must be printable ASCII
f9d13529 1436
7357bd17 1437(F) In C<\cI<X>>, I<X> must be a printable (non-control) ASCII character.
17a3df4c 1438
727b6379 1439Note that ASCII characters that don't map to control characters are
7357bd17 1440discouraged, and will generate the warning (when enabled)
727b6379 1441L</""\c%c" is more clearly written simply as "%s"">.
f9d13529 1442
f337b084 1443=item Character in 'C' format wrapped in pack
ac7cd81a
SC
1444
1445(W pack) You said
1446
1447 pack("C", $x)
1448
1449where $x is either less than 0 or more than 255; the C<"C"> format is
1450only for encoding native operating system characters (ASCII, EBCDIC,
1451and so on) and not for Unicode characters, so Perl behaved as if you meant
1452
1453 pack("C", $x & 255)
1454
1455If you actually want to pack Unicode codepoints, use the C<"U"> format
1456instead.
1457
f337b084 1458=item Character in 'c' format wrapped in pack
ac7cd81a
SC
1459
1460(W pack) You said
1461
1462 pack("c", $x)
1463
1464where $x is either less than -128 or more than 127; the C<"c"> format
1465is only for encoding native operating system characters (ASCII, EBCDIC,
1466and so on) and not for Unicode characters, so Perl behaved as if you meant
1467
1468 pack("c", $x & 255);
1469
1470If you actually want to pack Unicode codepoints, use the C<"U"> format
1471instead.
1472
f337b084
TH
1473=item Character in '%c' format wrapped in unpack
1474
1475(W unpack) You tried something like
1476
1477 unpack("H", "\x{2a1}")
1478
1a147d38 1479where the format expects to process a byte (a character with a value
6903afa2
FC
1480below 256), but a higher value was provided instead. Perl uses the
1481value modulus 256 instead, as if you had provided:
f337b084
TH
1482
1483 unpack("H", "\x{a1}")
1484
5a25739d
FC
1485=item Character in 'W' format wrapped in pack
1486
1487(W pack) You said
1488
1489 pack("U0W", $x)
1490
1491where $x is either less than 0 or more than 255. However, C<U0>-mode
1492expects all values to fall in the interval [0, 255], so Perl behaved
1493as if you meant:
1494
1495 pack("U0W", $x & 255)
1496
f337b084
TH
1497=item Character(s) in '%c' format wrapped in pack
1498
1499(W pack) You tried something like
1500
1501 pack("u", "\x{1f3}b")
1502
1a147d38 1503where the format expects to process a sequence of bytes (character with a
6903afa2 1504value below 256), but some of the characters had a higher value. Perl
f337b084
TH
1505uses the character values modulus 256 instead, as if you had provided:
1506
1507 pack("u", "\x{f3}b")
1508
1509=item Character(s) in '%c' format wrapped in unpack
1510
1511(W unpack) You tried something like
1512
1513 unpack("s", "\x{1f3}b")
1514
1a147d38 1515where the format expects to process a sequence of bytes (character with a
6903afa2 1516value below 256), but some of the characters had a higher value. Perl
f337b084
TH
1517uses the character values modulus 256 instead, as if you had provided:
1518
1519 unpack("s", "\x{f3}b")
1520
f51551f7
FC
1521=item charnames alias definitions may not contain a sequence of multiple spaces
1522
1523(F) You defined a character name which had multiple space characters
1524in a row. Change them to single spaces. Usually these names are
1525defined in the C<:alias> import argument to C<use charnames>, but they
1526could be defined by a translator installed into C<$^H{charnames}>. See
1527L<charnames/CUSTOM ALIASES>.
1528
1529=item charnames alias definitions may not contain trailing white-space
1530
1531(F) You defined a character name which ended in a space
1532character. Remove the trailing space(s). Usually these names are
1533defined in the C<:alias> import argument to C<use charnames>, but they
1534could be defined by a translator installed into C<$^H{charnames}>.
1535See L<charnames/CUSTOM ALIASES>.
1536
1537=item \C is deprecated in regex; marked by <-- HERE in m/%s/
1538
1539(D deprecated, regexp) The \C character class is deprecated, and will
1540become a compile-time error in a future release of perl (tentatively
3617dbb6
FC
1541v5.24). This construct allows you to match a single byte of what makes
1542up a multi-byte single UTF8 character, and breaks encapsulation. It is
1543currently also very buggy. If you really need to process the individual
f51551f7
FC
1544bytes, you probably want to convert your string to one where each
1545underlying byte is stored as a character, with utf8::encode().
1546
f866a7cd
FC
1547=item "\c%c" is more clearly written simply as "%s"
1548
1549(W syntax) The C<\cI<X>> construct is intended to be a way to specify
7ed0dd93
FC
1550non-printable characters. You used it for a printable one, which
1551is better written as simply itself, perhaps preceded by a backslash
1552for non-word characters. Doing it the way you did is not portable
1553between ASCII and EBCDIC platforms.
f866a7cd 1554
6651ba0b
FC
1555=item Cloning substitution context is unimplemented
1556
1557(F) Creating a new thread inside the C<s///> operator is not supported.
1558
abc7ecad
SP
1559=item closedir() attempted on invalid dirhandle %s
1560
1561(W io) The dirhandle you tried to close is either closed or not really
1562a dirhandle. Check your control flow.
1563
5a25739d
FC
1564=item close() on unopened filehandle %s
1565
1566(W unopened) You tried to close a filehandle that was never opened.
1567
541ed3a9
FC
1568=item Closure prototype called
1569
1570(F) If a closure has attributes, the subroutine passed to an attribute
1571handler is the prototype that is cloned when a new closure is created.
1572This subroutine cannot be called.
1573
49704364
LW
1574=item Code missing after '/'
1575
6903afa2
FC
1576(F) You had a (sub-)template that ends with a '/'. There must be
1577another template code following the slash. See L<perlfunc/pack>.
49704364 1578
5a25739d
FC
1579=item Code point 0x%X is not Unicode, may not be portable
1580
2d88a86a 1581(S non_unicode) You had a code point above the Unicode maximum
1b64326b
FC
1582of U+10FFFF.
1583
1584Perl allows strings to contain a superset of Unicode code points, up
1585to the limit of what is storable in an unsigned integer on your system,
1586but these may not be accepted by other languages/systems. At one time,
1587it was legal in some standards to have code points up to 0x7FFF_FFFF,
1588but not higher. Code points above 0xFFFF_FFFF require larger than a
158932 bit word.
0876b9a0 1590
6df41af2
GS
1591=item %s: Command not found
1592
a892b81a 1593(A) You've accidentally run your script through B<csh> or another shell
66a1f5ec
FC
1594instead of Perl. Check the #! line, or manually feed your script into
1595Perl yourself. The #! line at the top of your file could look like
8f721816
MM
1596
1597 #!/usr/bin/perl -w
6df41af2 1598
7a2e2cd6
PP
1599=item Compilation failed in require
1600
1601(F) Perl could not compile a file specified in a C<require> statement.
be771a83
GS
1602Perl uses this generic message when none of the errors that it
1603encountered were severe enough to halt compilation immediately.
7a2e2cd6 1604
c3464db5
DD
1605=item Complex regular subexpression recursion limit (%d) exceeded
1606
be771a83
GS
1607(W regexp) The regular expression engine uses recursion in complex
1608situations where back-tracking is required. Recursion depth is limited
1609to 32766, or perhaps less in architectures where the stack cannot grow
1610arbitrarily. ("Simple" and "medium" situations are handled without
1611recursion and are not subject to a limit.) Try shortening the string
1612under examination; looping in Perl code (e.g. with C<while>) rather than
1613in the regular expression engine; or rewriting the regular expression so
c2e66d9e 1614that it is simpler or backtracks less. (See L<perlfaq2> for information
be771a83 1615on I<Mastering Regular Expressions>.)
c3464db5 1616
69282e91 1617=item connect() on closed socket %s
a0d0e21e 1618
be771a83
GS
1619(W closed) You tried to do a connect on a closed socket. Did you forget
1620to check the return value of your socket() call? See
1621L<perlfunc/connect>.
a0d0e21e 1622
e21e7c6a
FC
1623=item Constant(%s): Call to &{$^H{%s}} did not return a defined value
1624
1625(F) The subroutine registered to handle constant overloading
1626(see L<overload>) or a custom charnames handler (see
1627L<charnames/CUSTOM TRANSLATORS>) returned an undefined value.
1628
1629=item Constant(%s): $^H{%s} is not defined
1630
1631(F) The parser found inconsistencies while attempting to define an
1632overloaded constant. Perhaps you forgot to load the corresponding
f738a371 1633L<overload> pragma?
e21e7c6a 1634
779c5bc9
GS
1635=item Constant is not %s reference
1636
1637(F) A constant value (perhaps declared using the C<use constant> pragma)
be771a83 1638is being dereferenced, but it amounts to the wrong type of reference.
6903afa2 1639The message indicates the type of reference that was expected. This
be771a83 1640usually indicates a syntax error in dereferencing the constant value.
779c5bc9
GS
1641See L<perlsub/"Constant Functions"> and L<constant>.
1642
0ac016fc
FC
1643=item Constants from lexical variables potentially modified elsewhere are
1644deprecated
1645
1646(D deprecated) You wrote something like
1647
1648 my $var;
1649 $sub = sub () { $var };
1650
1651but $var is referenced elsewhere and could be modified after the C<sub>
1652expression is evaluated. Either it is explicitly modified elsewhere
1653(C<$var = 3>) or it is passed to a subroutine or to an operator like
1654C<printf> or C<map>, which may or may not modify the variable.
1655
1656Traditionally, Perl has captured the value of the variable at that
1657point and turned the subroutine into a constant eligible for inlining.
1658In those cases where the variable can be modified elsewhere, this
1659breaks the behavior of closures, in which the subroutine captures
1660the variable itself, rather than its value, so future changes to the
1661variable are reflected in the subroutine's return value.
1662
1663This usage is deprecated, because the behavior is likely to change
1664in a future version of Perl.
1665
1666If you intended for the subroutine to be eligible for inlining, then
1667make sure the variable is not referenced elsewhere, possibly by
1668copying it:
1669
1670 my $var2 = $var;
1671 $sub = sub () { $var2 };
1672
1673If you do want this subroutine to be a closure that reflects future
1674changes to the variable that it closes over, add an explicit C<return>:
1675
1676 my $var;
1677 $sub = sub () { return $var };
1678
4cee8e80
CS
1679=item Constant subroutine %s redefined
1680
aeb94125
FC
1681(W redefine)(S) You redefined a subroutine which had previously
1682been eligible for inlining. See L<perlsub/"Constant Functions">
1683for commentary and workarounds.
4cee8e80 1684
9607fc9c
PP
1685=item Constant subroutine %s undefined
1686
be771a83
GS
1687(W misc) You undefined a subroutine which had previously been eligible
1688for inlining. See L<perlsub/"Constant Functions"> for commentary and
1689workarounds.
9607fc9c 1690
5a25739d
FC
1691=item Constant(%s) unknown
1692
1693(F) The parser found inconsistencies either while attempting
1694to define an overloaded constant, or when trying to find the
1695character name specified in the C<\N{...}> escape. Perhaps you
1696forgot to load the corresponding L<overload> pragma?.
1697
e7ea3e70
IZ
1698=item Copy method did not return a reference
1699
6903afa2 1700(F) The method which overloads "=" is buggy. See
13a2d996 1701L<overload/Copy Constructor>.
e7ea3e70 1702
4aaa4757
FC
1703=item &CORE::%s cannot be called directly
1704
1705(F) You tried to call a subroutine in the C<CORE::> namespace
8d605c0d 1706with C<&foo> syntax or through a reference. Some subroutines
4aaa4757
FC
1707in this package cannot yet be called that way, but must be
1708called as barewords. Something like this will work:
1709
1710 BEGIN { *shove = \&CORE::push; }
1711 shove @array, 1,2,3; # pushes on to @array
1712
6798c92b
GS
1713=item CORE::%s is not a keyword
1714
1715(F) The CORE:: namespace is reserved for Perl keywords.
1716
675fa9ff
FC
1717=item Corrupted regexp opcode %d > %d
1718
1719(P) This is either an error in Perl, or, if you're using
1720one, your L<custom regular expression engine|perlreapi>. If not the
1721latter, report the problem through the L<perlbug> utility.
1722
a0d0e21e
LW
1723=item corrupted regexp pointers
1724
1725(P) The regular expression engine got confused by what the regular
1726expression compiler gave it.
1727
1728=item corrupted regexp program
1729
be771a83
GS
1730(P) The regular expression engine got passed a regexp program without a
1731valid magic number.
a0d0e21e 1732
de42a5a9 1733=item Corrupt malloc ptr 0x%x at 0x%x
6df41af2
GS
1734
1735(P) The malloc package that comes with Perl had an internal failure.
1736
49704364
LW
1737=item Count after length/code in unpack
1738
1739(F) You had an unpack template indicating a counted-length string, but
1740you have also specified an explicit size for the string. See
1741L<perlfunc/pack>.
1742
f2cccb4c
KW
1743=for comment
1744The following are used in lib/diagnostics.t for testing two =items that
1745share the same description. Changes here need to be propagated to there
1746
6651ba0b
FC
1747=item Deep recursion on anonymous subroutine
1748
a0d0e21e
LW
1749=item Deep recursion on subroutine "%s"
1750
be771a83
GS
1751(W recursion) This subroutine has called itself (directly or indirectly)
1752100 times more than it has returned. This probably indicates an
1753infinite recursion, unless you're writing strange benchmark programs, in
1754which case it indicates something else.
a0d0e21e 1755
aad1d01f
NC
1756This threshold can be changed from 100, by recompiling the F<perl> binary,
1757setting the C pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value.
1758
e0e4a6e3
FC
1759=item (?(DEFINE)....) does not allow branches in regex; marked by
1760S<<-- HERE> in m/%s/
bcb95744 1761
6903afa2 1762(F) You used something like C<(?(DEFINE)...|..)> which is illegal. The
bcb95744
FC
1763most likely cause of this error is that you left out a parenthesis inside
1764of the C<....> part.
1765
9e3ec65c 1766The <-- HERE shows whereabouts in the regular expression the problem was
bcb95744
FC
1767discovered.
1768
62658f4d
PM
1769=item %s defines neither package nor VERSION--version check failed
1770
1771(F) You said something like "use Module 42" but in the Module file
1772there are neither package declarations nor a C<$VERSION>.
1773
36447869
FC
1774=item delete argument is index/value array slice, use array slice
1775
1776(F) You used index/value array slice syntax (C<%array[...]>) as
1777the argument to C<delete>. You probably meant C<@array[...]> with
1778an @ symbol instead.
1779
1780=item delete argument is key/value hash slice, use hash slice
1781
1782(F) You used key/value hash slice syntax (C<%hash{...}>) as the argument to
1783C<delete>. You probably meant C<@hash{...}> with an @ symbol instead.
1784
0ffcbc25
FC
1785=item delete argument is not a HASH or ARRAY element or slice
1786
4a0af295 1787(F) The argument to C<delete> must be either a hash or array element,
0ffcbc25
FC
1788such as:
1789
1790 $foo{$bar}
1791 $ref->{"susie"}[12]
1792
1793or a hash or array slice, such as:
1794
1795 @foo[$bar, $baz, $xyzzy]
1796 @{$ref->[12]}{"susie", "queue"}
1797
fc36a67e
PP
1798=item Delimiter for here document is too long
1799
be771a83
GS
1800(F) In a here document construct like C<<<FOO>, the label C<FOO> is too
1801long for Perl to handle. You have to be seriously twisted to write code
1802that triggers this error.
fc36a67e 1803
6d3b25aa
RGS
1804=item Deprecated use of my() in false conditional
1805
fa816bf3
FC
1806(D deprecated) You used a declaration similar to C<my $x if 0>. There
1807has been a long-standing bug in Perl that causes a lexical variable
6d3b25aa 1808not to be cleared at scope exit when its declaration includes a false
6903afa2 1809conditional. Some people have exploited this bug to achieve a kind of
fa816bf3 1810static variable. Since we intend to fix this bug, we don't want people
6903afa2 1811relying on this behavior. You can achieve a similar static effect by
6d3b25aa 1812declaring the variable in a separate block outside the function, eg
36fb85f3 1813
6d3b25aa
RGS
1814 sub f { my $x if 0; return $x++ }
1815
1816becomes
1817
1818 { my $x; sub f { return $x++ } }
1819
ea9d9ebc 1820Beginning with perl 5.10.0, you can also use C<state> variables to have
fa816bf3 1821lexicals that are initialized only once (see L<feature>):
36fb85f3
RGS
1822
1823 sub f { state $x; return $x++ }
1824
500ab966
RGS
1825=item DESTROY created new reference to dead object '%s'
1826
1827(F) A DESTROY() method created a new reference to the object which is
6903afa2
FC
1828just being DESTROYed. Perl is confused, and prefers to abort rather
1829than to create a dangling reference.
500ab966 1830
3cdd684c
TP
1831=item Did not produce a valid header
1832
1833See Server error.
1834
6df41af2
GS
1835=item %s did not return a true value
1836
1837(F) A required (or used) file must return a true value to indicate that
1838it compiled correctly and ran its initialization code correctly. It's
1839traditional to end such a file with a "1;", though any true value would
1840do. See L<perlfunc/require>.
1841
cc507455 1842=item (Did you mean &%s instead?)
4633a7c4 1843
413ff9f6
FC
1844(W misc) You probably referred to an imported subroutine &FOO as $FOO or
1845some such.
4633a7c4 1846
cc507455 1847=item (Did you mean "local" instead of "our"?)
33633739 1848
be771a83
GS
1849(W misc) Remember that "our" does not localize the declared global
1850variable. You have declared it again in the same lexical scope, which
1851seems superfluous.
33633739 1852
cc507455 1853=item (Did you mean $ or @ instead of %?)
a0d0e21e 1854
be771a83
GS
1855(W) You probably said %hash{$key} when you meant $hash{$key} or
1856@hash{@keys}. On the other hand, maybe you just meant %hash and got
1857carried away.
748a9306 1858
7e1af8bc 1859=item Died
5f05dabc
PP
1860
1861(F) You passed die() an empty string (the equivalent of C<die "">) or
075b00aa 1862you called it with no args and C<$@> was empty.
5f05dabc 1863
3cdd684c
TP
1864=item Document contains no data
1865
1866See Server error.
1867
62658f4d
PM
1868=item %s does not define %s::VERSION--version check failed
1869
1870(F) You said something like "use Module 42" but the Module did not
943fc58e 1871define a C<$VERSION>.
62658f4d 1872
49704364
LW
1873=item '/' does not take a repeat count
1874
1875(F) You cannot put a repeat count of any kind right after the '/' code.
1876See L<perlfunc/pack>.
1877
95cb0d72
FC
1878=item Don't know how to get file name
1879
1880(P) C<PerlIO_getname>, a perl internal I/O function specific to VMS, was
1881somehow called on another platform. This should not happen.
1882
4021c788 1883=item Don't know how to handle magic of type \%o
a0d0e21e
LW
1884
1885(P) The internal handling of magical variables has been cursed.
1886
1887=item do_study: out of memory
1888
1889(P) This should have been caught by safemalloc() instead.
1890
6df41af2
GS
1891=item (Do you need to predeclare %s?)
1892
56da5a46
RGS
1893(S syntax) This is an educated guess made in conjunction with the message
1894"%s found where operator expected". It often means a subroutine or module
6df41af2
GS
1895name is being referenced that hasn't been declared yet. This may be
1896because of ordering problems in your file, or because of a missing
be771a83
GS
1897"sub", "package", "require", or "use" statement. If you're referencing
1898something that isn't defined yet, you don't actually have to define the
1899subroutine or package before the current location. You can use an empty
1900"sub foo;" or "package FOO;" to enter a "forward" declaration.
6df41af2 1901
ac206dc8
RGS
1902=item dump() better written as CORE::dump()
1903
1904(W misc) You used the obsolescent C<dump()> built-in function, without fully
1905qualifying it as C<CORE::dump()>. Maybe it's a typo. See L<perlfunc/dump>.
1906
84d78eb7
YO
1907=item dump is not supported
1908
1909(F) Your machine doesn't support dump/undump.
1910
a0d0e21e
LW
1911=item Duplicate free() ignored
1912
be771a83
GS
1913(S malloc) An internal routine called free() on something that had
1914already been freed.
a0d0e21e 1915
1109a392
MHM
1916=item Duplicate modifier '%c' after '%c' in %s
1917
35f0cd76
FC
1918(W unpack) You have applied the same modifier more than once after a
1919type in a pack template. See L<perlfunc/pack>.
1109a392 1920
0953b66b
FC
1921=item each on reference is experimental
1922
0773cb3e
FC
1923(S experimental::autoderef) C<each> with a scalar argument is experimental
1924and may change or be removed in a future Perl version. If you want to
1925take the risk of using this feature, simply disable this warning:
0953b66b 1926
d401967c 1927 no warnings "experimental::autoderef";
0953b66b 1928
4633a7c4
LW
1929=item elseif should be elsif
1930
fa816bf3
FC
1931(S syntax) There is no keyword "elseif" in Perl because Larry thinks
1932it's ugly. Your code will be interpreted as an attempt to call a method
1933named "elseif" for the class returned by the following block. This is
4633a7c4
LW
1934unlikely to be what you want.
1935
e0e4a6e3 1936=item Empty \%c{} in regex; marked by S<<-- HERE> in m/%s/
ab13f0c7 1937
af6f566e 1938(F) C<\p> and C<\P> are used to introduce a named Unicode property, as
6903afa2 1939described in L<perlunicode> and L<perlre>. You used C<\p> or C<\P> in
af6f566e 1940a regular expression without specifying the property name.
ab13f0c7 1941
85ab1d1d 1942=item entering effective %s failed
5ff3f7a4 1943
85ab1d1d 1944(F) While under the C<use filetest> pragma, switching the real and
5ff3f7a4
GS
1945effective uids or gids failed.
1946
c038024b
RGS
1947=item %ENV is aliased to %s
1948
1949(F) You're running under taint mode, and the C<%ENV> variable has been
1950aliased to another hash, so it doesn't reflect anymore the state of the
6903afa2 1951program's environment. This is potentially insecure.
c038024b 1952
748a9306
LW
1953=item Error converting file specification %s
1954
5f05dabc 1955(F) An error peculiar to VMS. Because Perl may have to deal with file
748a9306 1956specifications in either VMS or Unix syntax, it converts them to a
be771a83
GS
1957single form when it must operate on them directly. Either you've passed
1958an invalid file specification to Perl, or you've found a case the
1959conversion routines don't handle. Drat.
748a9306 1960
ad19ef22 1961=item Eval-group in insecure regular expression
e4d48cc9 1962
be771a83
GS
1963(F) Perl detected tainted data when trying to compile a regular
1964expression that contains the C<(?{ ... })> zero-width assertion, which
1965is unsafe. See L<perlre/(?{ code })>, and L<perlsec>.
e4d48cc9 1966
ad19ef22 1967=item Eval-group not allowed at runtime, use re 'eval' in regex m/%s/
e4d48cc9 1968
be771a83
GS
1969(F) Perl tried to compile a regular expression containing the
1970C<(?{ ... })> zero-width assertion at run time, as it would when the
f11307f5
FC
1971pattern contains interpolated values. Since that is a security risk,
1972it is not allowed. If you insist, you may still do this by using the
1973C<re 'eval'> pragma or by explicitly building the pattern from an
1974interpolated string at run time and using that in an eval(). See
1975L<perlre/(?{ code })>.
e4d48cc9 1976
ad19ef22 1977=item Eval-group not allowed, use re 'eval' in regex m/%s/
6df41af2 1978
be771a83
GS
1979(F) A regular expression contained the C<(?{ ... })> zero-width
1980assertion, but that construct is only allowed when the C<use re 'eval'>
1981pragma is in effect. See L<perlre/(?{ code })>.
6df41af2 1982
e0e4a6e3
FC
1983=item EVAL without pos change exceeded limit in regex; marked by
1984S<<-- HERE> in m/%s/
1a147d38
YO
1985
1986(F) You used a pattern that nested too many EVAL calls without consuming
6903afa2 1987any text. Restructure the pattern so that text is consumed.
1a147d38 1988
9e3ec65c 1989The <-- HERE shows whereabouts in the regular expression the problem was
1a147d38
YO
1990discovered.
1991
fc36a67e
PP
1992=item Excessively long <> operator
1993
1994(F) The contents of a <> operator may not exceed the maximum size of a
1995Perl identifier. If you're just trying to glob a long list of
1996filenames, try using the glob() operator, or put the filenames into a
1997variable and glob that.
1998
ed9aa3b7
SG
1999=item exec? I'm not *that* kind of operating system
2000
af8bb25a 2001(F) The C<exec> function is not implemented on some systems, e.g., Symbian
6903afa2 2002OS. See L<perlport>.
ed9aa3b7 2003
fe13d51d 2004=item Execution of %s aborted due to compilation errors.
a0d0e21e
LW
2005
2006(F) The final summary message when a Perl compilation fails.
2007
0ffcbc25
FC
2008=item exists argument is not a HASH or ARRAY element or a subroutine
2009
4a0af295 2010(F) The argument to C<exists> must be a hash or array element or a
0ffcbc25
FC
2011subroutine with an ampersand, such as:
2012
2013 $foo{$bar}
2014 $ref->{"susie"}[12]
2015 &do_something
2016
2017=item exists argument is not a subroutine name
2018
ccfc2567
FC
2019(F) The argument to C<exists> for C<exists &sub> must be a subroutine name,
2020and not a subroutine call. C<exists &sub()> will generate this error.
0ffcbc25 2021
a0d0e21e
LW
2022=item Exiting eval via %s
2023
be771a83
GS
2024(W exiting) You are exiting an eval by unconventional means, such as a
2025goto, or a loop control statement.
e476b1b5
GS
2026
2027=item Exiting format via %s
2028
9a2ff54b 2029(W exiting) You are exiting a format by unconventional means, such as a
be771a83 2030goto, or a loop control statement.
a0d0e21e 2031
0a753a76
PP
2032=item Exiting pseudo-block via %s
2033
be771a83
GS
2034(W exiting) You are exiting a rather special block construct (like a
2035sort block or subroutine) by unconventional means, such as a goto, or a
2036loop control statement. See L<perlfunc/sort>.
0a753a76 2037
a0d0e21e
LW
2038=item Exiting subroutine via %s
2039
be771a83
GS
2040(W exiting) You are exiting a subroutine by unconventional means, such
2041as a goto, or a loop control statement.
a0d0e21e
LW
2042
2043=item Exiting substitution via %s
2044
be771a83
GS
2045(W exiting) You are exiting a substitution by unconventional means, such
2046as a return, a goto, or a loop control statement.
a0d0e21e 2047
e0e4a6e3 2048=item Expecting close bracket in regex; marked by S<<-- HERE> in m/%s/
c608e803 2049
675fa9ff 2050(F) You wrote something like
c608e803
KW
2051
2052 (?13
2053
2054to denote a capturing group of the form
2055L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>,
2056but omitted the C<")">.
2057
e0e4a6e3 2058=item Expecting '(?flags:(?[...' in regex; marked by S<<-- HERE> in m/%s/
27350048 2059
8b6fbf55
FC
2060(F) The C<(?[...])> extended character class regular expression construct
2061only allows character classes (including character class escapes like
2062C<\d>), operators, and parentheses. The one exception is C<(?flags:...)>
2063containing at least one flag and exactly one C<(?[...])> construct.
27350048
FC
2064This allows a regular expression containing just C<(?[...])> to be
2065interpolated. If you see this error message, then you probably
2066have some other C<(?...)> construct inside your character class. See
2067L<perlrecharclass/Extended Bracketed Character Classes>.
2068
baabe3fb 2069=item Experimental aliasing via reference not enabled
1f8155a2 2070
baabe3fb 2071(F) To do aliasing via references, you must first enable the feature:
1f8155a2 2072
baabe3fb
FC
2073 no warnings "experimental::refaliasing";
2074 use feature "refaliasing";
1f8155a2
FC
2075 \$x = \$y;
2076
30d9c59b
Z
2077=item Experimental subroutine signatures not enabled
2078
2079(F) To use subroutine signatures, you must first enable them:
2080
caa35032 2081 no warnings "experimental::signatures";
30d9c59b
Z
2082 use feature "signatures";
2083 sub foo ($left, $right) { ... }
2084
6da34ecb
FC
2085=item Experimental "%s" subs not enabled
2086
2087(F) To use lexical subs, you must first enable them:
2088
2089 no warnings 'experimental::lexical_subs';
2090 use feature 'lexical_subs';
2091 my sub foo { ... }
2092
7b8d334a
GS
2093=item Explicit blessing to '' (assuming package main)
2094
be771a83
GS
2095(W misc) You are blessing a reference to a zero length string. This has
2096the effect of blessing the reference into the package main. This is
2097usually not what you want. Consider providing a default target package,
2098e.g. bless($ref, $p || 'MyPackage');
7b8d334a 2099
6df41af2
GS
2100=item %s: Expression syntax
2101
be771a83
GS
2102(A) You've accidentally run your script through B<csh> instead of Perl.
2103Check the #! line, or manually feed your script into Perl yourself.
6df41af2
GS
2104
2105=item %s failed--call queue aborted
2106
3c10abe3
AG
2107(F) An untrapped exception was raised while executing a UNITCHECK,
2108CHECK, INIT, or END subroutine. Processing of the remainder of the
2109queue of such routines has been prematurely ended.
6df41af2 2110
e0e4a6e3 2111=item False [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
73b437c8 2112
98d31c73 2113(W regexp)(F) A character class range must start and end at a literal
7253e4e3 2114character, not another character class like C<\d> or C<[:alpha:]>. The "-"
3c6ca74a
FC
2115in your false range is interpreted as a literal "-". In a C<(?[...])>
2116construct, this is an error, rather than a warning. Consider quoting
e0e4a6e3 2117the "-", "\-". The S<<-- HERE> shows whereabouts in the regular expression
3c6ca74a 2118the problem was discovered. See L<perlre>.
73b437c8 2119
1b1ee2ef 2120=item Fatal VMS error (status=%d) at %s, line %d
a0d0e21e 2121
be771a83
GS
2122(P) An error peculiar to VMS. Something untoward happened in a VMS
2123system service or RTL routine; Perl's exit status should provide more
2124details. The filename in "at %s" and the line number in "line %d" tell
2125you which section of the Perl source code is distressed.
a0d0e21e
LW
2126
2127=item fcntl is not implemented
2128
2129(F) Your machine apparently doesn't implement fcntl(). What is this, a
2130PDP-11 or something?
2131
22846ab4
AB
2132=item FETCHSIZE returned a negative value
2133
2134(F) A tied array claimed to have a negative number of elements, which
2135is not possible.
2136
f337b084
TH
2137=item Field too wide in 'u' format in pack
2138
d8b5cc61 2139(W pack) Each line in an uuencoded string starts with a length indicator
6903afa2
FC
2140which can't encode values above 63. So there is no point in asking for
2141a line length bigger than that. Perl will behave as if you specified
5c96f6f7 2142C<u63> as the format.
f337b084 2143
af8c498a 2144=item Filehandle %s opened only for input
a0d0e21e 2145
6c8d78fb
HS
2146(W io) You tried to write on a read-only filehandle. If you intended
2147it to be a read-write filehandle, you needed to open it with "+<" or
2148"+>" or "+>>" instead of with "<" or nothing. If you intended only to
2149write the file, use ">" or ">>". See L<perlfunc/open>.
a0d0e21e 2150
af8c498a 2151=item Filehandle %s opened only for output
a0d0e21e 2152
6c8d78fb
HS
2153(W io) You tried to read from a filehandle opened only for writing, If
2154you intended it to be a read/write filehandle, you needed to open it
89a1bda8
FC
2155with "+<" or "+>" or "+>>" instead of with ">". If you intended only to
2156read from the file, use "<". See L<perlfunc/open>. Another possibility
2157is that you attempted to open filedescriptor 0 (also known as STDIN) for
2158output (maybe you closed STDIN earlier?).
97828cef
RGS
2159
2160=item Filehandle %s reopened as %s only for input
2161
2162(W io) You opened for reading a filehandle that got the same filehandle id
6903afa2 2163as STDOUT or STDERR. This occurred because you closed STDOUT or STDERR
97828cef
RGS
2164previously.
2165
2166=item Filehandle STDIN reopened as %s only for output
2167
2168(W io) You opened for writing a filehandle that got the same filehandle id
fa816bf3 2169as STDIN. This occurred because you closed STDIN previously.
a0d0e21e
LW
2170
2171=item Final $ should be \$ or $name
2172
2173(F) You must now decide whether the final $ in a string was meant to be
be771a83
GS
2174a literal dollar sign, or was meant to introduce a variable name that
2175happens to be missing. So you have to put either the backslash or the
2176name.
a0d0e21e 2177
56e90b21
GS
2178=item flock() on closed filehandle %s
2179
be771a83 2180(W closed) The filehandle you're attempting to flock() got itself closed
c289d2f7 2181some time before now. Check your control flow. flock() operates on
be771a83
GS
2182filehandles. Are you attempting to call flock() on a dirhandle by the
2183same name?
56e90b21 2184
6df41af2
GS
2185=item Format not terminated
2186
2187(F) A format must be terminated by a line with a solitary dot. Perl got
2188to the end of your file without finding such a line.
2189
a0d0e21e
LW
2190=item Format %s redefined
2191
e476b1b5 2192(W redefine) You redefined a format. To suppress this warning, say
a0d0e21e
LW
2193
2194 {
271595cc 2195 no warnings 'redefine';
a0d0e21e
LW
2196 eval "format NAME =...";
2197 }
2198
a0d0e21e
LW
2199=item Found = in conditional, should be ==
2200
e476b1b5 2201(W syntax) You said
a0d0e21e
LW
2202
2203 if ($foo = 123)
2204
2205when you meant
2206
2207 if ($foo == 123)
2208
2209(or something like that).
2210
6df41af2
GS
2211=item %s found where operator expected
2212
56da5a46
RGS
2213(S syntax) The Perl lexer knows whether to expect a term or an operator.
2214If it sees what it knows to be a term when it was expecting to see an
be771a83
GS
2215operator, it gives you this warning. Usually it indicates that an
2216operator or delimiter was omitted, such as a semicolon.
6df41af2 2217
a0d0e21e
LW
2218=item gdbm store returned %d, errno %d, key "%s"
2219
2220(S) A warning from the GDBM_File extension that a store failed.
2221
2222=item gethostent not implemented
2223
2224(F) Your C library apparently doesn't implement gethostent(), probably
2225because if it did, it'd feel morally obligated to return every hostname
2226on the Internet.
2227
69282e91 2228=item get%sname() on closed socket %s
a0d0e21e 2229
be771a83
GS
2230(W closed) You tried to get a socket or peer socket name on a closed
2231socket. Did you forget to check the return value of your socket() call?
a0d0e21e 2232
748a9306
LW
2233=item getpwnam returned invalid UIC %#o for user "%s"
2234
2235(S) A warning peculiar to VMS. The call to C<sys$getuai> underlying the
2236C<getpwnam> operator returned an invalid UIC.
2237
6df41af2
GS
2238=item getsockopt() on closed socket %s
2239
be771a83
GS
2240(W closed) You tried to get a socket option on a closed socket. Did you
2241forget to check the return value of your socket() call? See
6df41af2
GS
2242L<perlfunc/getsockopt>.
2243
0f539b13
BF
2244=item given is experimental
2245
675fa9ff
FC
2246(S experimental::smartmatch) C<given> depends on smartmatch, which
2247is experimental, so its behavior may change or even be removed
2248in any future release of perl. See the explanation under
2249L<perlsyn/Experimental Details on given and when>.
0f539b13 2250
68567d27
FC
2251=item Global symbol "%s" requires explicit package name (did you forget to
2252declare "my %s"?)
6df41af2 2253
a4edf47d 2254(F) You've said "use strict" or "use strict vars", which indicates
30c282f6 2255that all variables must either be lexically scoped (using "my" or "state"),
a4edf47d
GS
2256declared beforehand using "our", or explicitly qualified to say
2257which package the global variable is in (using "::").
6df41af2 2258
e476b1b5
GS
2259=item glob failed (%s)
2260
5ead438e 2261(S glob) Something went wrong with the external program(s) used
73c4e9dc
FC
2262for C<glob> and C<< <*.c> >>. Usually, this means that you supplied a C<glob>
2263pattern that caused the external program to fail and exit with a
be771a83 2264nonzero status. If the message indicates that the abnormal exit
73c4e9dc
FC
2265resulted in a coredump, this may also mean that your csh (C shell)
2266is broken. If so, you should change all of the csh-related variables
2267in config.sh: If you have tcsh, make the variables refer to it as
2268if it were csh (e.g. C<full_csh='/usr/bin/tcsh'>); otherwise, make them
2269all empty (except that C<d_csh> should be C<'undef'>) so that Perl will
be771a83 2270think csh is missing. In either case, after editing config.sh, run
75b44862 2271C<./Configure -S> and rebuild Perl.
e476b1b5 2272
a0d0e21e
LW
2273=item Glob not terminated
2274
2275(F) The lexer saw a left angle bracket in a place where it was expecting
be771a83
GS
2276a term, so it's looking for the corresponding right angle bracket, and
2277not finding it. Chances are you left some needed parentheses out
2278earlier in the line, and you really meant a "less than".
a0d0e21e 2279
b35b96b6
JH
2280=item gmtime(%f) failed
2281
2282(W overflow) You called C<gmtime> with a number that it could not handle:
2283too large, too small, or NaN. The returned value is C<undef>.
2284
bcd05b94 2285=item gmtime(%f) too large
8b56d6ff 2286
e9200be3 2287(W overflow) You called C<gmtime> with a number that was larger than
fc003d4b 2288it can reliably handle and C<gmtime> probably returned the wrong
6903afa2 2289date. This warning is also triggered with NaN (the special
fc003d4b
MS
2290not-a-number value).
2291
bcd05b94 2292=item gmtime(%f) too small
fc003d4b 2293
e9200be3 2294(W overflow) You called C<gmtime> with a number that was smaller than
e7a1a147 2295it can reliably handle and C<gmtime> probably returned the wrong date.
8b56d6ff 2296
6df41af2 2297=item Got an error from DosAllocMem
a0d0e21e 2298
6df41af2
GS
2299(P) An error peculiar to OS/2. Most probably you're using an obsolete
2300version of Perl, and this should not happen anyway.
a0d0e21e
LW
2301
2302=item goto must have label
2303
2304(F) Unlike with "next" or "last", you're not allowed to goto an
2305unspecified destination. See L<perlfunc/goto>.
2306
6651ba0b
FC
2307=item Goto undefined subroutine%s
2308
2309(F) You tried to call a subroutine with C<goto &sub> syntax, but
2310the indicated subroutine hasn't been defined, or if it was, it
2311has since been undefined.
2312
6fbc9859 2313=item Group name must start with a non-digit word character in regex; marked by
e0e4a6e3 2314S<<-- HERE> in m/%s/
1f4f6bf1
YO
2315
2316(F) Group names must follow the rules for perl identifiers, meaning
f26c79ba
FC
2317they must start with a non-digit word character. A common cause of
2318this error is using (?&0) instead of (?0). See L<perlre>.
1f4f6bf1 2319
5a25739d
FC
2320=item ()-group starts with a count
2321
2322(F) A ()-group started with a count. A count is supposed to follow
2323something: a template character or a ()-group. See L<perlfunc/pack>.
2324
fe13d51d 2325=item %s had compilation errors.
6df41af2
GS
2326
2327(F) The final summary message when a C<perl -c> fails.
2328
a0d0e21e
LW
2329=item Had to create %s unexpectedly
2330
be771a83
GS
2331(S internal) A routine asked for a symbol from a symbol table that ought
2332to have existed already, but for some reason it didn't, and had to be
2333created on an emergency basis to prevent a core dump.
a0d0e21e 2334
6df41af2
GS
2335=item %s has too many errors
2336
2337(F) The parser has given up trying to parse the program after 10 errors.
2338Further error messages would likely be uninformative.
2339
cc4d09e1
KW
2340=item Having more than one /%c regexp modifier is deprecated
2341
2342(D deprecated, regexp) You used the indicated regular expression pattern
2343modifier at least twice in a string of modifiers. It is deprecated to
2344do this with this particular modifier, to allow future extensions to the
2345Perl language.
2346
61e61fbc
JH
2347=item Hexadecimal float: exponent overflow
2348
d8f2b442 2349(W overflow) The hexadecimal floating point has a larger exponent
61e61fbc
JH
2350than the floating point supports.
2351
2352=item Hexadecimal float: exponent underflow
2353
d8f2b442 2354(W overflow) The hexadecimal floating point has a smaller exponent
61e61fbc
JH
2355than the floating point supports.
2356
cf4f6003
JH
2357=item Hexadecimal float: internal error
2358
2359(F) Something went horribly bad in hexadecimal float handling.
2360
61e61fbc
JH
2361=item Hexadecimal float: mantissa overflow
2362
2363(W overflow) The hexadecimal floating point literal had more bits in
2364the mantissa (the part between the 0x and the exponent, also known as
2365the fraction or the significand) than the floating point supports.
2366
40bca5ae
JH
2367=item Hexadecimal float: precision loss
2368
2369(W overflow) The hexadecimal floating point had internally more
2370digits than could be output. This can be caused by unsupported
2371long double formats, or by 64-bit integers not being available
2372(needed to retrieve the digits under some configurations).
2373
2374=item Hexadecimal float: unsupported long double format
2375
2376(F) You have configured Perl to use long doubles but
d8f2b442 2377the internals of the long double format are unknown;
40bca5ae
JH
2378therefore the hexadecimal float output is impossible.
2379
252aa082
JH
2380=item Hexadecimal number > 0xffffffff non-portable
2381
e476b1b5 2382(W portable) The hexadecimal number you specified is larger than 2**32-1
9e24b6e2
JH
2383(4294967295) and therefore non-portable between systems. See
2384L<perlport> for more on portability concerns.
252aa082 2385
8903cb82
PP
2386=item Identifier too long
2387
2388(F) Perl limits identifiers (names for variables, functions, etc.) to
fc36a67e 2389about 250 characters for simple names, and somewhat more for compound
be771a83
GS
2390names (like C<$A::B>). You've exceeded Perl's limits. Future versions
2391of Perl are likely to eliminate these arbitrary limitations.
8903cb82 2392
e0e4a6e3
FC
2393=item Ignoring zero length \N{} in character class in regex; marked by
2394S<<-- HERE> in m/%s/
fc8cd66c 2395
f3ba6905 2396(W regexp) Named Unicode character escapes (C<\N{...}>) may return a
0f44b2a5
FC
2397zero-length sequence. When such an escape is used in a character
2398class its behavior is not well defined. Check that the correct
2399escape has been used, and the correct charname handler is in scope.
fc8cd66c 2400
6df41af2 2401=item Illegal binary digit %s
f675dbe5 2402
6df41af2 2403(F) You used a digit other than 0 or 1 in a binary number.
f675dbe5 2404
6df41af2 2405=item Illegal binary digit %s ignored
a0d0e21e 2406
be771a83
GS
2407(W digit) You may have tried to use a digit other than 0 or 1 in a
2408binary number. Interpretation of the binary number stopped before the
2409offending digit.
a0d0e21e 2410
6597eb22
FC
2411=item Illegal character after '_' in prototype for %s : %s
2412
e4d150f1
FC
2413(W illegalproto) An illegal character was found in a prototype
2414declaration. The '_' in a prototype must be followed by a ';',
2415indicating the rest of the parameters are optional, or one of '@'
2416or '%', since those two will accept 0 or more final parameters.
6597eb22 2417
78d0fecf 2418=item Illegal character \%o (carriage return)
4fdae800 2419
d5898338 2420(F) Perl normally treats carriage returns in the program text as it
be771a83
GS
2421would any other whitespace, which means you should never see this error
2422when Perl was built using standard options. For some reason, your
2423version of Perl appears to have been built without this support. Talk
2424to your Perl administrator.
4fdae800 2425
d37a9538
ST
2426=item Illegal character in prototype for %s : %s
2427
197afce1 2428(W illegalproto) An illegal character was found in a prototype declaration.
2e9cc7ef 2429Legal characters in prototypes are $, @, %, *, ;, [, ], &, \, and +.
30d9c59b
Z
2430Perhaps you were trying to write a subroutine signature but didn't enable
2431that feature first (C<use feature 'signatures'>), so your signature was
2432instead interpreted as a bad prototype.
d37a9538 2433
904d85c5
RGS
2434=item Illegal declaration of anonymous subroutine
2435
2436(F) When using the C<sub> keyword to construct an anonymous subroutine,
6903afa2 2437you must always specify a block of code. See L<perlsub>.
904d85c5 2438
8e742a20
MHM
2439=item Illegal declaration of subroutine %s
2440
6903afa2 2441(F) A subroutine was not declared correctly. See L<perlsub>.
8e742a20 2442
a0d0e21e
LW
2443=item Illegal division by zero
2444
be771a83
GS
2445(F) You tried to divide a number by 0. Either something was wrong in
2446your logic, or you need to put a conditional in to guard against
2447meaningless input.
a0d0e21e 2448
6df41af2
GS
2449=item Illegal hexadecimal digit %s ignored
2450
be771a83
GS
2451(W digit) You may have tried to use a character other than 0 - 9 or
2452A - F, a - f in a hexadecimal number. Interpretation of the hexadecimal
2453number stopped before the illegal character.
6df41af2 2454
a0d0e21e
LW
2455=item Illegal modulus zero
2456
be771a83
GS
2457(F) You tried to divide a number by 0 to get the remainder. Most
2458numbers don't take to this kindly.
a0d0e21e 2459
6df41af2 2460=item Illegal number of bits in vec
399388f4 2461
6df41af2
GS
2462(F) The number of bits in vec() (the third argument) must be a power of
2463two from 1 to 32 (or 64, if your platform supports that).
399388f4
GS
2464
2465=item Illegal octal digit %s
a0d0e21e 2466
d1be9408 2467(F) You used an 8 or 9 in an octal number.
a0d0e21e 2468
399388f4 2469=item Illegal octal digit %s ignored
748a9306 2470
d1be9408 2471(W digit) You may have tried to use an 8 or 9 in an octal number.
75b44862 2472Interpretation of the octal number stopped before the 8 or 9.
748a9306 2473
e0e4a6e3 2474=item Illegal pattern in regex; marked by S<<-- HERE> in m/%s/
c608e803 2475
675fa9ff 2476(F) You wrote something like
c608e803
KW
2477
2478 (?+foo)
2479
2480The C<"+"> is valid only when followed by digits, indicating a
2481capturing group. See
2482L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>.
2483
375ed12a
JH
2484=item Illegal suidscript
2485
2486(F) The script run under suidperl was somehow illegal.
2487
fe13d51d 2488=item Illegal switch in PERL5OPT: -%c
6ff81951 2489
6df41af2 2490(X) The PERL5OPT environment variable may only be used to set the
646ca9b2 2491following switches: B<-[CDIMUdmtw]>.
6ff81951 2492
6df41af2 2493=item Ill-formed CRTL environ value "%s"
81e118e0 2494
75b44862 2495(W internal) A warning peculiar to VMS. Perl tried to read the CRTL's
be771a83
GS
2496internal environ array, and encountered an element without the C<=>
2497delimiter used to separate keys from values. The element is ignored.
09bef843 2498
6df41af2 2499=item Ill-formed message in prime_env_iter: |%s|
54310121 2500
be771a83
GS
2501(W internal) A warning peculiar to VMS. Perl tried to read a logical
2502name or CLI symbol definition when preparing to iterate over %ENV, and
2503didn't see the expected delimiter between key and value, so the line was
2504ignored.
54310121 2505
6df41af2 2506=item (in cleanup) %s
9607fc9c 2507
be771a83
GS
2508(W misc) This prefix usually indicates that a DESTROY() method raised
2509the indicated exception. Since destructors are usually called by the
2510system at arbitrary points during execution, and often a vast number of
2511times, the warning is issued only once for any number of failures that
2512would otherwise result in the same message being repeated.
6df41af2 2513
be771a83
GS
2514Failure of user callbacks dispatched using the C<G_KEEPERR> flag could
2515also result in this warning. See L<perlcall/G_KEEPERR>.
9607fc9c 2516
e0e4a6e3
FC
2517=item Incomplete expression within '(?[ ])' in regex; marked by S<<-- HERE>
2518in m/%s/
0d0b4b3b 2519
675fa9ff 2520(F) There was a syntax error within the C<(?[ ])>. This can happen if the
0d0b4b3b
KW
2521expression inside the construct was completely empty, or if there are
2522too many or few operands for the number of operators. Perl is not smart
2523enough to give you a more precise indication as to what is wrong.
2524
6fbc9859
MH
2525=item Inconsistent hierarchy during C3 merge of class '%s': merging failed on
2526parent '%s'
2c7d6b9c
RGS
2527
2528(F) The method resolution order (MRO) of the given class is not
2529C3-consistent, and you have enabled the C3 MRO for this class. See the C3
2530documentation in L<mro> for more information.
2531
979699d9
JH
2532=item In EBCDIC the v-string components cannot exceed 2147483647
2533
2534(F) An error peculiar to EBCDIC. Internally, v-strings are stored as
2535Unicode code points, and encoded in EBCDIC as UTF-EBCDIC. The UTF-EBCDIC
2536encoding is limited to code points no larger than 2147483647 (0x7FFFFFFF).
2537
6a2ed79a 2538=item Infinite recursion in regex
1a147d38
YO
2539
2540(F) You used a pattern that references itself without consuming any input
6903afa2 2541text. You should check the pattern to ensure that recursive patterns
1a147d38
YO
2542either consume text or fail.
2543
6dbe9451
NC
2544=item Initialization of state variables in list context currently forbidden
2545
6903afa2
FC
2546(F) Currently the implementation of "state" only permits the
2547initialization of scalar variables in scalar context. Re-write
2548C<state ($a) = 42> as C<state $a = 42> to change from list to scalar
2549context. Constructions such as C<state (@a) = foo()> will be
2550supported in a future perl release.
6dbe9451 2551
2186f873
FC
2552=item %%s[%s] in scalar context better written as $%s[%s]
2553
2554(W syntax) In scalar context, you've used an array index/value slice
2555(indicated by %) to select a single element of an array. Generally
2556it's better to ask for a scalar value (indicated by $). The difference
2557is that C<$foo[&bar]> always behaves like a scalar, both in the value it
2558returns and when evaluating its argument, while C<%foo[&bar]> provides
2559a list context to its subscript, which can do weird things if you're
2560expecting only one subscript. When called in list context, it also
2561returns the index (what C<&bar> returns) in addition to the value.
2562
2563=item %%s{%s} in scalar context better written as $%s{%s}
2564
2565(W syntax) In scalar context, you've used a hash key/value slice
2566(indicated by %) to select a single element of a hash. Generally it's
2567better to ask for a scalar value (indicated by $). The difference
2568is that C<$foo{&bar}> always behaves like a scalar, both in the value
2569it returns and when evaluating its argument, while C<@foo{&bar}> and
2570provides a list context to its subscript, which can do weird things
2571if you're expecting only one subscript. When called in list context,
2572it also returns the key in addition to the value.
2573
a0d0e21e
LW
2574=item Insecure dependency in %s
2575
8b1a09fc 2576(F) You tried to do something that the tainting mechanism didn't like.
be771a83
GS
2577The tainting mechanism is turned on when you're running setuid or
2578setgid, or when you specify B<-T> to turn it on explicitly. The
2579tainting mechanism labels all data that's derived directly or indirectly
2580from the user, who is considered to be unworthy of your trust. If any
2581such data is used in a "dangerous" operation, you get this error. See
2582L<perlsec> for more information.
a0d0e21e
LW
2583
2584=item Insecure directory in %s
2585
be771a83
GS
2586(F) You can't use system(), exec(), or a piped open in a setuid or
2587setgid script if C<$ENV{PATH}> contains a directory that is writable by
df98f984
RGS
2588the world. Also, the PATH must not contain any relative directory.
2589See L<perlsec>.
a0d0e21e 2590
62f468fc 2591=item Insecure $ENV{%s} while running %s
a0d0e21e
LW
2592
2593(F) You can't use system(), exec(), or a piped open in a setuid or
62f468fc 2594setgid script if any of C<$ENV{PATH}>, C<$ENV{IFS}>, C<$ENV{CDPATH}>,
332d5f78
SR
2595C<$ENV{ENV}>, C<$ENV{BASH_ENV}> or C<$ENV{TERM}> are derived from data
2596supplied (or potentially supplied) by the user. The script must set
2597the path to a known value, using trustworthy data. See L<perlsec>.
a0d0e21e 2598
0e9be77f
DM
2599=item Insecure user-defined property %s
2600
2601(F) Perl detected tainted data when trying to compile a regular
2602expression that contains a call to a user-defined character property
2603function, i.e. C<\p{IsFoo}> or C<\p{InFoo}>.
2604See L<perlunicode/User-Defined Character Properties> and L<perlsec>.
2605
b9ef414d
FC
2606=item Integer overflow in format string for %s
2607
2608(F) The indexes and widths specified in the format string of C<printf()>
2609or C<sprintf()> are too large. The numbers must not overflow the size of
2610integers for your architecture.
2611
a7ae9550
GS
2612=item Integer overflow in %s number
2613
35928bc5 2614(S overflow) The hexadecimal, octal or binary number you have specified
be771a83
GS
2615either as a literal or as an argument to hex() or oct() is too big for
2616your architecture, and has been converted to a floating point number.
2617On a 32-bit architecture the largest hexadecimal, octal or binary number
9e24b6e2
JH
2618representable without overflow is 0xFFFFFFFF, 037777777777, or
26190b11111111111111111111111111111111 respectively. Note that Perl
2620transparently promotes all numbers to a floating point representation
2621internally--subject to loss of precision errors in subsequent
2622operations.
bbce6d69 2623
fc89ca81
FC
2624=item Integer overflow in srand
2625
2626(S overflow) The number you have passed to srand is too big to fit
2627in your architecture's integer representation. The number has been
2628replaced with the largest integer supported (0xFFFFFFFF on 32-bit
2629architectures). This means you may be getting less randomness than
2630you expect, because different random seeds above the maximum will
2631return the same sequence of random numbers.
2632
46314c13
JP
2633=item Integer overflow in version
2634
18da5252
FC
2635=item Integer overflow in version %d
2636
784d71ed
FC
2637(W overflow) Some portion of a version initialization is too large for
2638the size of integers for your architecture. This is not a warning
f084e84f 2639because there is no rational reason for a version to try and use an
784d71ed
FC
2640element larger than typically 2**32. This is usually caused by trying
2641to use some odd mathematical operation as a version, like 100/9.
46314c13 2642
e0e4a6e3 2643=item Internal disaster in regex; marked by S<<-- HERE> in m/%s/
6df41af2
GS
2644
2645(P) Something went badly wrong in the regular expression parser.
e0e4a6e3 2646The S<<-- HERE> shows whereabouts in the regular expression the problem was
b45f050a
JF
2647discovered.
2648
748a9306
LW
2649=item Internal inconsistency in tracking vforks
2650
be771a83
GS
2651(S) A warning peculiar to VMS. Perl keeps track of the number of times
2652you've called C<fork> and C<exec>, to determine whether the current call
2653to C<exec> should affect the current script or a subprocess (see
2654L<perlvms/"exec LIST">). Somehow, this count has become scrambled, so
2655Perl is making a guess and treating this C<exec> as a request to
2656terminate the Perl script and execute the specified command.
748a9306 2657
870978ae
FC
2658=item internal %<num>p might conflict with future printf extensions
2659
2660(S internal) Perl's internal routine that handles C<printf> and C<sprintf>
2661formatting follows a slightly different set of rules when called from
2662C or XS code. Specifically, formats consisting of digits followed
2663by "p" (e.g., "%7p") are reserved for future use. If you see this
2664message, then an XS module tried to call that routine with one such
2665reserved format.
2666
e0e4a6e3 2667=item Internal urp in regex; marked by S<<-- HERE> in m/%s/
b45f050a 2668
fa816bf3 2669(P) Something went badly awry in the regular expression parser. The
e0e4a6e3 2670S<<-- HERE> shows whereabouts in the regular expression the problem was
7253e4e3 2671discovered.
a0d0e21e 2672
6df41af2
GS
2673=item %s (...) interpreted as function
2674
75b44862 2675(W syntax) You've run afoul of the rule that says that any list operator
be771a83 2676followed by parentheses turns into a function, with all the list
64977eb6 2677operators arguments found inside the parentheses. See
13a2d996 2678L<perlop/Terms and List Operators (Leftward)>.
6df41af2 2679
f51551f7
FC
2680=item In '(?...)', the '(' and '?' must be adjacent in regex;
2681marked by S<<-- HERE> in m/%s/
2682
2683(F) The two-character sequence C<"(?"> in this context in a regular
2684expression pattern should be an indivisible token, with nothing
2685intervening between the C<"("> and the C<"?">, but you separated them
2686with whitespace.
2687
09bef843
SB
2688=item Invalid %s attribute: %s
2689
a4a4c9e2 2690(F) The indicated attribute for a subroutine or variable was not recognized
09bef843
SB
2691by Perl or by a user-supplied handler. See L<attributes>.
2692
2693=item Invalid %s attributes: %s
2694
a4a4c9e2 2695(F) The indicated attributes for a subroutine or variable were not
be771a83 2696recognized by Perl or by a user-supplied handler. See L<attributes>.
09bef843 2697
e0e4a6e3
FC
2698=item Invalid character in charnames alias definition; marked by
2699S<<-- HERE> in '%s
225fb84f
KW
2700
2701(F) You tried to create a custom alias for a character name, with
2702the C<:alias> option to C<use charnames> and the specified character in
2703the indicated name isn't valid. See L<charnames/CUSTOM ALIASES>.
2704
c8028aa6
TC
2705=item Invalid \0 character in %s for %s: %s\0%s
2706
fa3234e3
FC
2707(W syscalls) Embedded \0 characters in pathnames or other system call
2708arguments produce a warning as of 5.20. The parts after the \0 were
2709formerly ignored by system calls.
c8028aa6 2710
e0e4a6e3 2711=item Invalid character in \N{...}; marked by S<<-- HERE> in \N{%s}
a690c7c4
FC
2712
2713(F) Only certain characters are valid for character names. The
2714indicated one isn't. See L<charnames/CUSTOM ALIASES>.
2715
c635e13b
PP
2716=item Invalid conversion in %s: "%s"
2717
be771a83
GS
2718(W printf) Perl does not understand the given format conversion. See
2719L<perlfunc/sprintf>.
c635e13b 2720
e0e4a6e3
FC
2721=item Invalid escape in the specified encoding in regex; marked by
2722S<<-- HERE> in m/%s/
9e08bc66 2723
98d31c73 2724(W regexp)(F) The numeric escape (for example C<\xHH>) of value < 256
9e08bc66
ST
2725didn't correspond to a single character through the conversion
2726from the encoding specified by the encoding pragma.
98d31c73
FC
2727The escape was replaced with REPLACEMENT CHARACTER (U+FFFD)
2728instead, except within S<C<(?[ ])>>, where it is a fatal error.
e0e4a6e3 2729The S<<-- HERE> shows whereabouts in the regular expression the
9e08bc66
ST
2730escape was discovered.
2731
af5e7be2
FC
2732=item %s: Invalid handshake key got %p needed %p, binaries are mismatched
2733
2734(P) A dynamic loading library C<.so> or C<.dll> was being loaded into the
2735process that was built against a different build of perl than the
2736said library was compiled against. Reinstalling the XS module will
2737likely fix this error.
2738
8149aa9f
FC
2739=item Invalid hexadecimal number in \N{U+...}
2740
e0e4a6e3
FC
2741=item Invalid hexadecimal number in \N{U+...} in regex; marked by
2742S<<-- HERE> in m/%s/
aec0ef10 2743
8149aa9f 2744(F) The character constant represented by C<...> is not a valid hexadecimal
74f8e9e3
FC
2745number. Either it is empty, or you tried to use a character other than
27460 - 9 or A - F, a - f in a hexadecimal number.
8149aa9f 2747
6651ba0b
FC
2748=item Invalid module name %s with -%c option: contains single ':'
2749
2750(F) The module argument to perl's B<-m> and B<-M> command-line options
2751cannot contain single colons in the module name, but only in the
2752arguments after "=". In other words, B<-MFoo::Bar=:baz> is ok, but
2753B<-MFoo:Bar=baz> is not.
2754
2c7d6b9c
RGS
2755=item Invalid mro name: '%s'
2756
162a3e34
FC
2757(F) You tried to C<mro::set_mro("classname", "foo")> or C<use mro 'foo'>,
2758where C<foo> is not a valid method resolution order (MRO). Currently,
2759the only valid ones supported are C<dfs> and C<c3>, unless you have loaded
2760a module that is a MRO plugin. See L<mro> and L<perlmroapi>.
2c7d6b9c 2761
40e4140b
FC
2762=item Invalid negative number (%s) in chr
2763
2764(W utf8) You passed a negative number to C<chr>. Negative numbers are
abc0aa9d 2765not valid character numbers, so it returns the Unicode replacement
40e4140b
FC
2766character (U+FFFD).
2767
6651ba0b
FC
2768=item invalid option -D%c, use -D'' to see choices
2769
8ff21bfe
FC
2770(S debugging) Perl was called with invalid debugger flags. Call perl
2771with the B<-D> option with no flags to see the list of acceptable values.
982c4ecb 2772See also L<perlrun/-Dletters>.
6651ba0b 2773
e0e4a6e3 2774=item Invalid [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
6df41af2
GS
2775
2776(F) The range specified in a character class had a minimum character
7253e4e3
RK
2777greater than the maximum character. One possibility is that you forgot the
2778C<{}> from your ending C<\x{}> - C<\x> without the curly braces can go only
e0e4a6e3 2779up to C<ff>. The S<<-- HERE> shows whereabouts in the regular expression the
7253e4e3 2780problem was discovered. See L<perlre>.
6df41af2 2781
d1573ac7 2782=item Invalid range "%s" in transliteration operator
c2e66d9e
GS
2783
2784(F) The range specified in the tr/// or y/// operator had a minimum
2785character greater than the maximum character. See L<perlop>.
2786
09bef843
SB
2787=item Invalid separator character %s in attribute list
2788
0120eecf 2789(F) Something other than a colon or whitespace was seen between the
be771a83
GS
2790elements of an attribute list. If the previous attribute had a
2791parenthesised parameter list, perhaps that list was terminated too soon.
2792See L<attributes>.
09bef843 2793
b4581f09
JH
2794=item Invalid separator character %s in PerlIO layer specification %s
2795
2bfc5f71
FC
2796(W layer) When pushing layers onto the Perl I/O system, something other
2797than a colon or whitespace was seen between the elements of a layer list.
b4581f09
JH
2798If the previous attribute had a parenthesised parameter list, perhaps that
2799list was terminated too soon.
2800
2c86d456
DG
2801=item Invalid strict version format (%s)
2802
fa816bf3 2803(F) A version number did not meet the "strict" criteria for versions.
2c86d456
DG
2804A "strict" version number is a positive decimal number (integer or
2805decimal-fraction) without exponentiation or else a dotted-decimal
2806v-string with a leading 'v' character and at least three components.
a6485a24 2807The parenthesized text indicates which criteria were not met.
2c86d456
DG
2808See the L<version> module for more details on allowed version formats.
2809
49704364 2810=item Invalid type '%s' in %s
96e4d5b1 2811
49704364
LW
2812(F) The given character is not a valid pack or unpack type.
2813See L<perlfunc/pack>.
6728c851 2814
49704364 2815(W) The given character is not a valid pack or unpack type but used to be
75b44862 2816silently ignored.
96e4d5b1 2817
2c86d456
DG
2818=item Invalid version format (%s)
2819
fa816bf3 2820(F) A version number did not meet the "lax" criteria for versions.
2c86d456
DG
2821A "lax" version number is a positive decimal number (integer or
2822decimal-fraction) without exponentiation or else a dotted-decimal
fa816bf3
FC
2823v-string. If the v-string has fewer than three components, it
2824must have a leading 'v' character. Otherwise, the leading 'v' is
2825optional. Both decimal and dotted-decimal versions may have a
2826trailing "alpha" component separated by an underscore character
2827after a fractional or dotted-decimal component. The parenthesized
2828text indicates which criteria were not met. See the L<version> module
2829for more details on allowed version formats.
46314c13 2830
798ae1b7
DG
2831=item Invalid version object
2832
fa816bf3
FC
2833(F) The internal structure of the version object was invalid.
2834Perhaps the internals were modified directly in some way or
2835an arbitrary reference was blessed into the "version" class.
798ae1b7 2836
cd209d9d 2837=item In '(*VERB...)', the '(' and '*' must be adjacent in regex;
e0e4a6e3 2838marked by S<<-- HERE> in m/%s/
675fa9ff 2839
cd209d9d 2840(F) The two-character sequence C<"(*"> in
675fa9ff
FC
2841this context in a regular expression pattern should be an
2842indivisible token, with nothing intervening between the C<"(">
cd209d9d 2843and the C<"*">, but you separated them.
675fa9ff 2844
a0d0e21e
LW
2845=item ioctl is not implemented
2846
2847(F) Your machine apparently doesn't implement ioctl(), which is pretty
2848strange for a machine that supports C.
2849
c289d2f7
JH
2850=item ioctl() on unopened %s
2851
2852(W unopened) You tried ioctl() on a filehandle that was never opened.
34b6fd5e 2853Check your control flow and number of arguments.
c289d2f7 2854
fe13d51d 2855=item IO layers (like '%s') unavailable
363c40c4
SB
2856
2857(F) Your Perl has not been configured to have PerlIO, and therefore
34b6fd5e 2858you cannot use IO layers. To have PerlIO, Perl must be configured
363c40c4
SB
2859with 'useperlio'.
2860
80cbd5ad
JH
2861=item IO::Socket::atmark not implemented on this architecture
2862
2863(F) Your machine doesn't implement the sockatmark() functionality,
34b6fd5e 2864neither as a system call nor an ioctl call (SIOCATMARK).
80cbd5ad 2865
4f650b80 2866=item $* is no longer supported
b4581f09 2867
4f650b80 2868(D deprecated, syntax) The special variable C<$*>, deprecated in older
ea9d9ebc 2869perls, has been removed as of 5.10.0 and is no longer supported. In
4f650b80
NC
2870previous versions of perl the use of C<$*> enabled or disabled multi-line
2871matching within a string.
4fd19576
B
2872
2873Instead of using C<$*> you should use the C</m> (and maybe C</s>) regexp
6903afa2
FC
2874modifiers. You can enable C</m> for a lexical scope (even a whole file)
2875with C<use re '/m'>. (In older versions: when C<$*> was set to a true value
570dedd4 2876then all regular expressions behaved as if they were written using C</m>.)
b4581f09 2877
8ae1fe26
RGS
2878=item $# is no longer supported
2879
a58ac25e 2880(D deprecated, syntax) The special variable C<$#>, deprecated in older
ea9d9ebc 2881perls, has been removed as of 5.10.0 and is no longer supported. You
a58ac25e 2882should use the printf/sprintf functions instead.
8ae1fe26 2883
ccf3535a 2884=item '%s' is not a code reference
6ad11d81 2885
6903afa2
FC
2886(W overload) The second (fourth, sixth, ...) argument of
2887overload::constant needs to be a code reference. Either
2888an anonymous subroutine, or a reference to a subroutine.
6ad11d81 2889
ccf3535a 2890=item '%s' is not an overloadable type
6ad11d81 2891
04a80ee0
RGS
2892(W overload) You tried to overload a constant type the overload package is
2893unaware of.
6ad11d81 2894
5a25739d
FC
2895=item -i used with no filenames on the command line, reading from STDIN
2896
2897(S inplace) The C<-i> option was passed on the command line, indicating
2898that the script is intended to edit files in place, but no files were
2899given. This is usually a mistake, since editing STDIN in place doesn't
2900make sense, and can be confusing because it can make perl look like
2901it is hanging when it is really just trying to read from STDIN. You
2902should either pass a filename to edit, or remove C<-i> from the command
2903line. See L<perlrun> for more details.
2904
aec0ef10 2905=item Junk on end of regexp in regex m/%s/
a0d0e21e
LW
2906
2907(P) The regular expression parser is confused.
2908
0953b66b
FC
2909=item keys on reference is experimental
2910
0773cb3e
FC
2911(S experimental::autoderef) C<keys> with a scalar argument is experimental
2912and may change or be removed in a future Perl version. If you want to
2913take the risk of using this feature, simply disable this warning:
0953b66b 2914
d401967c 2915 no warnings "experimental::autoderef";
0953b66b 2916
a0d0e21e
LW
2917=item Label not found for "last %s"
2918
be771a83
GS
2919(F) You named a loop to break out of, but you're not currently in a loop
2920of that name, not even if you count where you were called from. See
2921L<perlfunc/last>.
a0d0e21e
LW
2922
2923=item Label not found for "next %s"
2924
2925(F) You named a loop to continue, but you're not currently in a loop of
2926that name, not even if you count where you were called from. See
2927L<perlfunc/last>.
2928
2929=item Label not found for "redo %s"
2930
2931(F) You named a loop to restart, but you're not currently in a loop of
2932that name, not even if you count where you were called from. See
2933L<perlfunc/last>.
2934
85ab1d1d 2935=item leaving effective %s failed
5ff3f7a4 2936
85ab1d1d 2937(F) While under the C<use filetest> pragma, switching the real and
5ff3f7a4
GS
2938effective uids or gids failed.
2939
49704364
LW
2940=item length/code after end of string in unpack
2941
d7f8936a 2942(F) While unpacking, the string buffer was already used up when an unpack
6903afa2
FC
2943length/code combination tried to obtain more data. This results in
2944an undefined value for the length. See L<perlfunc/pack>.
49704364 2945
25e26107 2946=item length() used on %s (did you mean "scalar(%s)"?)
e508c8a4 2947
0d46a4e7
FC
2948(W syntax) You used length() on either an array or a hash when you
2949probably wanted a count of the items.
e508c8a4
MH
2950
2951Array size can be obtained by doing:
2952
2953 scalar(@array);
2954
2955The number of items in a hash can be obtained by doing:
2956
2957 scalar(keys %hash);
2958
f0e67a1d
Z
2959=item Lexing code attempted to stuff non-Latin-1 character into Latin-1 input
2960
d4fe7078
RS
2961(F) An extension is attempting to insert text into the current parse
2962(using L<lex_stuff_pvn|perlapi/lex_stuff_pvn> or similar), but tried to insert a character that
2963couldn't be part of the current input. This is an inherent pitfall
2964of the stuffing mechanism, and one of the reasons to avoid it. Where
6903afa2 2965it is necessary to stuff, stuffing only plain ASCII is recommended.
f0e67a1d
Z
2966
2967=item Lexing code internal error (%s)
2968
2969(F) Lexing code supplied by an extension violated the lexer's API in a
2970detectable way.
2971
69282e91 2972=item listen() on closed socket %s
a0d0e21e 2973
be771a83
GS
2974(W closed) You tried to do a listen on a closed socket. Did you forget
2975to check the return value of your socket() call? See
2976L<perlfunc/listen>.
a0d0e21e 2977
6651ba0b
FC
2978=item List form of piped open not implemented
2979
2980(F) On some platforms, notably Windows, the three-or-more-arguments
2981form of C<open> does not support pipes, such as C<open($pipe, '|-', @args)>.
2982Use the two-argument C<open($pipe, '|prog arg1 arg2...')> form instead.
2983
b35b96b6
JH
2984=item localtime(%f) failed
2985
2986(W overflow) You called C<localtime> with a number that it could not handle:
2987too large, too small, or NaN. The returned value is C<undef>.
2988
bcd05b94 2989=item localtime(%f) too large
8b56d6ff 2990
e9200be3 2991(W overflow) You called C<localtime> with a number that was larger
fc003d4b 2992than it can reliably handle and C<localtime> probably returned the
6903afa2 2993wrong date. This warning is also triggered with NaN (the special
fc003d4b
MS
2994not-a-number value).
2995
bcd05b94 2996=item localtime(%f) too small
fc003d4b 2997
e9200be3 2998(W overflow) You called C<localtime> with a number that was smaller
fc003d4b 2999than it can reliably handle and C<localtime> probably returned the
e7a1a147 3000wrong date.
8b56d6ff 3001
58e23c8d 3002=item Lookbehind longer than %d not implemented in regex m/%s/
b45f050a
JF
3003
3004(F) There is currently a limit on the length of string which lookbehind can
6903afa2 3005handle. This restriction may be eased in a future release.
2e50fd82 3006
b88df990
NC
3007=item Lost precision when %s %f by 1
3008
e63e8a91
FC
3009(W imprecision) The value you attempted to increment or decrement by one
3010is too large for the underlying floating point representation to store
3011accurately, hence the target of C<++> or C<--> is unchanged. Perl issues this
3012warning because it has already switched from integers to floating point
3013when values are too large for integers, and now even floating point is
3014insufficient. You may wish to switch to using L<Math::BigInt> explicitly.
b88df990 3015
93fad930 3016=item lstat() on filehandle%s
2f7da168
RK
3017
3018(W io) You tried to do an lstat on a filehandle. What did you mean
3019by that? lstat() makes sense only on filenames. (Perl did a fstat()
3020instead on the filehandle.)
3021
345d70e3 3022=item lvalue attribute %s already-defined subroutine
bb3abb05 3023
345d70e3
FC
3024(W misc) Although L<attributes.pm|attributes> allows this, turning the lvalue
3025attribute on or off on a Perl subroutine that is already defined
3026does not always work properly. It may or may not do what you
3027want, depending on what code is inside the subroutine, with exact
3028details subject to change between Perl versions. Only do this
3029if you really know what you are doing.
bb3abb05 3030
885ef6f5
GG
3031=item lvalue attribute ignored after the subroutine has been defined
3032
345d70e3
FC
3033(W misc) Using the C<:lvalue> declarative syntax to make a Perl
3034subroutine an lvalue subroutine after it has been defined is
3035not permitted. To make the subroutine an lvalue subroutine,
3036add the lvalue attribute to the definition, or put the C<sub
3037foo :lvalue;> declaration before the definition.
3038
3039See also L<attributes.pm|attributes>.
885ef6f5 3040
6f1b3ab0
FC
3041=item Magical list constants are not supported
3042
3043(F) You assigned a magical array to a stash element, and then tried
3044to use the subroutine from the same slot. You are asking Perl to do
3045something it cannot do, details subject to change between Perl versions.
3046
2db62bbc 3047=item Malformed integer in [] in pack
49704364 3048
2db62bbc 3049(F) Between the brackets enclosing a numeric repeat count only digits
49704364
LW
3050are permitted. See L<perlfunc/pack>.
3051
3052=item Malformed integer in [] in unpack
3053
2db62bbc 3054(F) Between the brackets enclosing a numeric repeat count only digits
49704364
LW
3055are permitted. See L<perlfunc/pack>.
3056
6df41af2
GS
3057=item Malformed PERLLIB_PREFIX
3058
3059(F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form
3060
3061 prefix1;prefix2
3062
3063or
6df41af2
GS
3064 prefix1 prefix2
3065
be771a83
GS
3066with nonempty prefix1 and prefix2. If C<prefix1> is indeed a prefix of
3067a builtin library search path, prefix2 is substituted. The error may
3068appear if components are not found, or are too long. See
fecfaeb8 3069"PERLLIB_PREFIX" in L<perlos2>.
6df41af2 3070
2f758a16
ST
3071=item Malformed prototype for %s: %s
3072
d37a9538
ST
3073(F) You tried to use a function with a malformed prototype. The
3074syntax of function prototypes is given a brief compile-time check for
3075obvious errors like invalid characters. A more rigorous check is run
3076when the function is called.
30d9c59b
Z
3077Perhaps the function's author was trying to write a subroutine signature
3078but didn't enable that feature first (C<use feature 'signatures'>),
3079so the signature was instead interpreted as a bad prototype.
2f758a16 3080
ba210ebe
JH
3081=item Malformed UTF-8 character (%s)
3082
4d6f11e5 3083(S utf8)(F) Perl detected a string that didn't comply with UTF-8
2575c402 3084encoding rules, even though it had the UTF8 flag on.
ba210ebe 3085
2575c402
JW
3086One possible cause is that you set the UTF8 flag yourself for data that
3087you thought to be in UTF-8 but it wasn't (it was for example legacy
6903afa2 30888-bit data). To guard against this, you can use Encode::decode_utf8.
2575c402
JW
3089
3090If you use the C<:encoding(UTF-8)> PerlIO layer for input, invalid byte
3091sequences are handled gracefully, but if you use C<:utf8>, the flag is
3092set without validating the data, possibly resulting in this error
3093message.
3094
3095See also L<Encode/"Handling Malformed Data">.
901b21bf 3096
107160e2
KW
3097=item Malformed UTF-8 character immediately after '%s'
3098
3099(F) You said C<use utf8>, but the program file doesn't comply with UTF-8
3100encoding rules. The message prints out the properly encoded characters
3101just before the first bad one. If C<utf8> warnings are enabled, a
3102warning is generated that gives more details about the type of
3103malformation.
3104
bde9e88d 3105=item Malformed UTF-8 returned by \N{%s} immediately after '%s'
ff3f963a
KW
3106
3107(F) The charnames handler returned malformed UTF-8.
3108
4a5d3a93
FC
3109=item Malformed UTF-8 string in '%c' format in unpack
3110
3111(F) You tried to unpack something that didn't comply with UTF-8 encoding
3112rules and perl was unable to guess how to make more progress.
3113
f337b084
TH
3114=item Malformed UTF-8 string in pack
3115
3116(F) You tried to pack something that didn't comply with UTF-8 encoding
3117rules and perl was unable to guess how to make more progress.
3118
3119=item Malformed UTF-8 string in unpack
3120
3121(F) You tried to unpack something that didn't comply with UTF-8 encoding
3122rules and perl was unable to guess how to make more progress.
3123
4a5d3a93 3124=item Malformed UTF-16 surrogate
f337b084 3125
4a5d3a93
FC
3126(F) Perl thought it was reading UTF-16 encoded character data but while
3127doing it Perl met a malformed Unicode surrogate.
3128
30d9c59b
Z
3129=item Mandatory parameter follows optional parameter
3130
3131(F) In a subroutine signature, you wrote something like "$a = undef,
3132$b", making an earlier parameter optional and a later one mandatory.
3133Parameters are filled from left to right, so it's impossible for the
3134caller to omit an earlier one and pass a later one. If you want to act
3135as if the parameters are filled from right to left, declare the rightmost
3136optional and then shuffle the parameters around in the subroutine's body.
3137
2d88a86a
KW
3138=item Matched non-Unicode code point 0x%X against Unicode property; may
3139not be portable
3140
3141(S non_unicode) Perl allows strings to contain a superset of
3142Unicode code points; each code point may be as large as what is storable
3143in an unsigned integer on your system, but these may not be accepted by
3144other languages/systems. This message occurs when you matched a string
3145containing such a code point against a regular expression pattern, and
3146the code point was matched against a Unicode property, C<\p{...}> or
3147C<\P{...}>. Unicode properties are only defined on Unicode code points,
3148so the result of this match is undefined by Unicode, but Perl (starting
3149in v5.20) treats non-Unicode code points as if they were typical
3150unassigned Unicode ones, and matched this one accordingly. Whether a
3151given property matches these code points or not is specified in
3152L<perluniprops/Properties accessible through \p{} and \P{}>.
3153
3154This message is suppressed (unless it has been made fatal) if it is
3155immaterial to the results of the match if the code point is Unicode or
3156not. For example, the property C<\p{ASCII_Hex_Digit}> only can match
3157the 22 characters C<[0-9A-Fa-f]>, so obviously all other code points,
3158Unicode or not, won't match it. (And C<\P{ASCII_Hex_Digit}> will match
3159every code point except these 22.)
3160
3161Getting this message indicates that the outcome of the match arguably
3162should have been the opposite of what actually happened. If you think
3163that is the case, you may wish to make the C<non_unicode> warnings
3164category fatal; if you agree with Perl's decision, you may wish to turn
3165off this category.
3166
3167See L<perlunicode/Beyond Unicode code points> for more information.
3168
e0e4a6e3
FC
3169=item %s matches null string many times in regex; marked by S<<-- HERE> in
3170m/%s/
4a5d3a93
FC
3171
3172(W regexp) The pattern you've specified would be an infinite loop if the
e0e4a6e3 3173regular expression engine didn't specifically check for that. The S<<-- HERE>
9e3ec65c 3174shows whereabouts in the regular expression the problem was discovered.
4a5d3a93 3175See L<perlre>.
f337b084 3176
de42a5a9 3177=item Maximal count of pending signals (%u) exceeded
2563cec5 3178
6903afa2 3179(F) Perl aborted due to too high a number of signals pending. This
2563cec5
IZ
3180usually indicates that your operating system tried to deliver signals
3181too fast (with a very high priority), starving the perl process from
3182resources it would need to reach a point where it can process signals
6903afa2 3183safely. (See L<perlipc/"Deferred Signals (Safe Signals)">.)
2563cec5 3184
25f58aea
PN
3185=item "%s" may clash with future reserved word
3186
3187(W) This warning may be due to running a perl5 script through a perl4
3188interpreter, especially if the word that is being warned about is
3189"use" or "my".
3190
0d2487cd 3191=item '%' may not be used in pack
6df41af2
GS
3192
3193(F) You can't pack a string by supplying a checksum, because the
be771a83
GS
3194checksumming process loses information, and you can't go the other way.
3195See L<perlfunc/unpack>.
6df41af2 3196
a0d0e21e
LW
3197=item Method for operation %s not found in package %s during blessing
3198
3199(F) An attempt was made to specify an entry in an overloading table that
e7ea3e70 3200doesn't resolve to a valid subroutine. See L<overload>.
a0d0e21e 3201
3cdd684c
TP
3202=item Method %s not permitted
3203
3204See Server error.
3205
a0d0e21e
LW
3206=item Might be a runaway multi-line %s string starting on line %d
3207
3208(S) An advisory indicating that the previous error may have been caused
3209by a missing delimiter on a string or pattern, because it eventually
3210ended earlier on the current line.
3211
3212=item Misplaced _ in number
3213
d4ced10d
JH
3214(W syntax) An underscore (underbar) in a numeric constant did not
3215separate two digits.
a0d0e21e 3216
7baa4690
HS
3217=item Missing argument in %s
3218
3664866e
AB
3219(W missing) You called a function with fewer arguments than other
3220arguments you supplied indicated would be needed.
3221
3222Currently only emitted when a printf-type format required more
3223arguments than were supplied, but might be used in the future for
3224other cases where we can statically determine that arguments to
3225functions are missing, e.g. for the L<perlfunc/pack> function.
7baa4690 3226
9e81e6a1
RGS
3227=item Missing argument to -%c
3228
3229(F) The argument to the indicated command line switch must follow
3230immediately after the switch, without intervening spaces.
3231
ff3f963a 3232=item Missing braces on \N{}
423cee85 3233
e0e4a6e3 3234=item Missing braces on \N{} in regex; marked by S<<-- HERE> in m/%s/
aec0ef10 3235
4a2d328f 3236(F) Wrong syntax of character name literal C<\N{charname}> within
532cb70d
FC
3237double-quotish context. This can also happen when there is a space
3238(or comment) between the C<\N> and the C<{> in a regex with the C</x> modifier.
3239This modifier does not change the requirement that the brace immediately
3240follow the C<\N>.
423cee85 3241
f0a2b745
KW
3242=item Missing braces on \o{}
3243
3244(F) A C<\o> must be followed immediately by a C<{> in double-quotish context.
3245
a0d0e21e
LW
3246=item Missing comma after first argument to %s function
3247
3248(F) While certain functions allow you to specify a filehandle or an
3249"indirect object" before the argument list, this ain't one of them.
3250
06eaf0bc
GS
3251=item Missing command in piped open
3252
be771a83
GS
3253(W pipe) You used the C<open(FH, "| command")> or
3254C<open(FH, "command |")> construction, but the command was missing or
3255blank.
06eaf0bc 3256
961ce445
RGS
3257=item Missing control char name in \c
3258
3259(F) A double-quoted string ended with "\c", without the required control
3260character name.
3261
591f5ca2
FC
3262=item Missing ']' in prototype for %s : %s
3263
bfe11873 3264(W illegalproto) A grouping was started with C<[> but never closed with C<]>.
591f5ca2 3265
8767b1ab 3266=item Missing name in "%s sub"
6df41af2 3267
87444db5 3268(F) The syntax for lexically scoped subroutines requires that
be771a83 3269they have a name with which they can be found.
6df41af2
GS
3270
3271=item Missing $ on loop variable
3272
be771a83
GS
3273(F) Apparently you've been programming in B<csh> too much. Variables
3274are always mentioned with the $ in Perl, unlike in the shells, where it
3275can vary from one line to the next.
6df41af2 3276
cc507455 3277=item (Missing operator before %s?)
748a9306 3278
56da5a46
RGS
3279(S syntax) This is an educated guess made in conjunction with the message
3280"%s found where operator expected". Often the missing operator is a comma.
748a9306 3281
f51551f7
FC
3282=item Missing or undefined argument to require
3283
3284(F) You tried to call require with no argument or with an undefined
3285value as an argument. Require expects either a package name or a
3286file-specification as an argument. See L<perlfunc/require>.
3287
e0e4a6e3 3288=item Missing right brace on \%c{} in regex; marked by S<<-- HERE> in m/%s/
ab13f0c7 3289
ff3f963a
KW
3290(F) Missing right brace in C<\x{...}>, C<\p{...}>, C<\P{...}>, or C<\N{...}>.
3291
4a68bf9d 3292=item Missing right brace on \N{} or unescaped left brace after \N
ff3f963a 3293
d32207c9
FC
3294(F) C<\N> has two meanings.
3295
3296The traditional one has it followed by a name enclosed in braces,
3297meaning the character (or sequence of characters) given by that
fa816bf3 3298name. Thus C<\N{ASTERISK}> is another way of writing C<*>, valid in both
d32207c9
FC
3299double-quoted strings and regular expression patterns. In patterns,
3300it doesn't have the meaning an unescaped C<*> does.
3301
3302Starting in Perl 5.12.0, C<\N> also can have an additional meaning (only)
3303in patterns, namely to match a non-newline character. (This is short
3304for C<[^\n]>, and like C<.> but is not affected by the C</s> regex modifier.)
3305
3306This can lead to some ambiguities. When C<\N> is not followed immediately
3307by a left brace, Perl assumes the C<[^\n]> meaning. Also, if the braces
3308form a valid quantifier such as C<\N{3}> or C<\N{5,}>, Perl assumes that this
3309means to match the given quantity of non-newlines (in these examples,
33103; and 5 or more, respectively). In all other case, where there is a
3311C<\N{> and a matching C<}>, Perl assumes that a character name is desired.
3312
3313However, if there is no matching C<}>, Perl doesn't know if it was
3314mistakenly omitted, or if C<[^\n]{> was desired, and raises this error.
3315If you meant the former, add the right brace; if you meant the latter,
3316escape the brace with a backslash, like so: C<\N\{>
ab13f0c7 3317
d98d5fff 3318=item Missing right curly or square bracket
a0d0e21e 3319
be771a83
GS
3320(F) The lexer counted more opening curly or square brackets than closing
3321ones. As a general rule, you'll find it's missing near the place you
3322were last editing.
a0d0e21e 3323
6df41af2
GS
3324=item (Missing semicolon on previous line?)
3325
56da5a46
RGS
3326(S syntax) This is an educated guess made in conjunction with the message
3327"%s found where operator expected". Don't automatically put a semicolon on
6df41af2
GS
3328the previous line just because you saw this message.
3329
a0d0e21e
LW
3330=item Modification of a read-only value attempted
3331
3332(F) You tried, directly or indirectly, to change the value of a
5f05dabc 3333constant. You didn't, of course, try "2 = 1", because the compiler
a0d0e21e
LW
3334catches that. But an easy way to do the same thing is:
3335
3336 sub mod { $_[0] = 1 }
3337 mod(2);