This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
pack c/C on inf/nan.
[perl5.git] / pod / perldiag.pod
CommitLineData
a0d0e21e
LW
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).
a0d0e21e
LW
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.
e476b1b5
GS
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.
e476b1b5
GS
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__}>
e476b1b5
GS
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
4438c4b7
JH
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
6df41af2
GS
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.
a0d0e21e
LW
44
45=over 4
46
6df41af2 47=item accept() on closed socket %s
33633739 48
be771a83
GS
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
de42a5a9 53=item Allocation too large: %x
a0d0e21e 54
6df41af2 55(X) You can't allocate more than 64K on an MS-DOS machine.
a0d0e21e 56
04f74579 57=item '%c' allowed only after types %s in %s
ef54e1a4 58
1109a392
MHM
59(F) The modifiers '!', '<' and '>' are allowed in pack() or unpack() only
60after certain types. See L<perlfunc/pack>.
ef54e1a4 61
6df41af2 62=item Ambiguous call resolved as CORE::%s(), qualify as such or use &
43192e07 63
75b44862 64(W ambiguous) A subroutine you have declared has the same name as a Perl
be771a83
GS
65keyword, and you have used the name without qualification for calling
66one or the other. Perl decided to call the builtin because the
67subroutine is not imported.
43192e07 68
6df41af2
GS
69To force interpretation as a subroutine call, either put an ampersand
70before the subroutine name, or qualify the name with its package.
71Alternatively, you can import the subroutine (or pretend that it's
72imported with the C<use subs> pragma).
43192e07 73
6df41af2 74To silently interpret it as the Perl operator, use the C<CORE::> prefix
496a33f5 75on the operator (e.g. C<CORE::log($x)>) or declare the subroutine
be771a83
GS
76to be an object method (see L<perlsub/"Subroutine Attributes"> or
77L<attributes>).
43192e07 78
c2e66d9e
GS
79=item Ambiguous range in transliteration operator
80
81(F) You wrote something like C<tr/a-z-0//> which doesn't mean anything at
82all. To include a C<-> character in a transliteration, put it either
83first or last. (In the past, C<tr/a-z-0//> was synonymous with
84C<tr/a-y//>, which was probably not what you would have expected.)
85
6df41af2 86=item Ambiguous use of %s resolved as %s
43192e07 87
7c7af292 88(S ambiguous) You said something that may not be interpreted the way
6df41af2
GS
89you thought. Normally it's pretty easy to disambiguate it by supplying
90a missing quote, operator, parenthesis pair or declaration.
a0d0e21e 91
591f5ca2
FC
92=item Ambiguous use of -%s resolved as -&%s()
93
94(S ambiguous) You wrote something like C<-foo>, which might be the
95string C<"-foo">, or a call to the function C<foo>, negated. If you meant
96the string, just write C<"-foo">. If you meant the function call,
97write C<-foo()>.
98
d8225693
JM
99=item Ambiguous use of %c resolved as operator %c
100
7c7af292 101(S ambiguous) C<%>, C<&>, and C<*> are both infix operators (modulus,
3303f755
FC
102bitwise and, and multiplication) I<and> initial special characters
103(denoting hashes, subroutines and typeglobs), and you said something
104like C<*foo * foo> that might be interpreted as either of them. We
105assumed you meant the infix operator, but please try to make it more
106clear -- in the example given, you might write C<*foo * foo()> if you
107really meant to multiply a glob by the result of calling a function.
d8225693 108
1ef43bca
JM
109=item Ambiguous use of %c{%s} resolved to %c%s
110
111(W ambiguous) You wrote something like C<@{foo}>, which might be
112asking for the variable C<@foo>, or it might be calling a function
113named foo, and dereferencing it as an array reference. If you wanted
1cecf2c0 114the variable, you can just write C<@foo>. If you wanted to call the
1ef43bca
JM
115function, write C<@{foo()}> ... or you could just not have a variable
116and a function with the same name, and save yourself a lot of trouble.
117
e850844c
FC
118=item Ambiguous use of %c{%s[...]} resolved to %c%s[...]
119
120=item Ambiguous use of %c{%s{...}} resolved to %c%s{...}
4da60377 121
fa816bf3
FC
122(W ambiguous) You wrote something like C<${foo[2]}> (where foo represents
123the name of a Perl keyword), which might be looking for element number
1242 of the array named C<@foo>, in which case please write C<$foo[2]>, or you
125might have meant to pass an anonymous arrayref to the function named
126foo, and then do a scalar deref on the value it returns. If you meant
127that, write C<${foo([2])}>.
ccaaf480
FC
128
129In regular expressions, the C<${foo[2]}> syntax is sometimes necessary
130to disambiguate between array subscripts and character classes.
fa816bf3
FC
131C</$length[2345]/>, for instance, will be interpreted as C<$length> followed
132by the character class C<[2345]>. If an array subscript is what you
133want, you can avoid the warning by changing C</${length[2345]}/> to the
134unsightly C</${\$length[2345]}/>, by renaming your array to something
135that does not coincide with a built-in keyword, or by simply turning
136off warnings with C<no warnings 'ambiguous';>.
4da60377 137
6df41af2 138=item '|' and '<' may not both be specified on command line
a0d0e21e 139
be771a83
GS
140(F) An error peculiar to VMS. Perl does its own command line
141redirection, and found that STDIN was a pipe, and that you also tried to
142redirect STDIN using '<'. Only one STDIN stream to a customer, please.
c9f97d15 143
6df41af2 144=item '|' and '>' may not both be specified on command line
1028017a 145
be771a83
GS
146(F) An error peculiar to VMS. Perl does its own command line
147redirection, and thinks you tried to redirect stdout both to a file and
148into a pipe to another command. You need to choose one or the other,
149though nothing's stopping you from piping into a program or Perl script
150which 'splits' output into two streams, such as
1028017a 151
6df41af2
GS
152 open(OUT,">$ARGV[0]") or die "Can't write to $ARGV[0]: $!";
153 while (<STDIN>) {
154 print;
155 print OUT;
156 }
157 close OUT;
c9f97d15 158
6df41af2 159=item Applying %s to %s will act on scalar(%s)
eb6e2d6f 160
496a33f5
SC
161(W misc) The pattern match (C<//>), substitution (C<s///>), and
162transliteration (C<tr///>) operators work on scalar values. If you apply
be771a83 163one of them to an array or a hash, it will convert the array or hash to
ac036724 164a scalar value (the length of an array, or the population info of a
165hash) and then work on that scalar value. This is probably not what
be771a83
GS
166you meant to do. See L<perlfunc/grep> and L<perlfunc/map> for
167alternatives.
eb6e2d6f 168
6df41af2 169=item Arg too short for msgsnd
76cd736e 170
6df41af2 171(F) msgsnd() requires a string at least as long as sizeof(long).
76cd736e 172
f86702cc 173=item Argument "%s" isn't numeric%s
a0d0e21e 174
be771a83
GS
175(W numeric) The indicated string was fed as an argument to an operator
176that expected a numeric value instead. If you're fortunate the message
177will identify which operator was so unfortunate.
a0d0e21e 178
b4581f09
JH
179=item Argument list not closed for PerlIO layer "%s"
180
a534ac11
FC
181(W layer) When pushing a layer with arguments onto the Perl I/O
182system you forgot the ) that closes the argument list. (Layers
183take care of transforming data between external and internal
184representations.) Perl stopped parsing the layer list at this
185point and did not attempt to push this layer. If your program
186didn't explicitly request the failing operation, it may be the
187result of the value of the environment variable PERLIO.
b4581f09 188
3f7602fa
TC
189=item Argument "%s" treated as 0 in increment (++)
190
191(W numeric) The indicated string was fed as an argument to the C<++>
192operator which expects either a number or a string matching
193C</^[a-zA-Z]*[0-9]*\z/>. See L<perlop/Auto-increment and
194Auto-decrement> for details.
195
a0d0e21e
LW
196=item assertion botched: %s
197
21b5e840 198(X) The malloc package that comes with Perl had an internal failure.
a0d0e21e 199
0eacef8e 200=item Assertion %s failed: file "%s", line %d
a0d0e21e 201
21b5e840 202(X) A general assertion failed. The file in question must be examined.
a0d0e21e 203
82122228
FC
204=item Assigning non-zero to $[ is no longer possible
205
7d345e3d
FC
206(F) When the "array_base" feature is disabled (e.g., under C<use v5.16;>)
207the special variable C<$[>, which is deprecated, is now a fixed zero value.
82122228 208
a0d0e21e
LW
209=item Assignment to both a list and a scalar
210
211(F) If you assign to a conditional operator, the 2nd and 3rd arguments
212must either both be scalars or both be lists. Otherwise Perl won't
213know which context to supply to the right side.
214
f51551f7
FC
215=item <> at require-statement should be quotes
216
217(F) You wrote C<< require <file> >> when you should have written
218C<require 'file'>.
219
2393f1b9 220=item Attempt to access disallowed key '%s' in a restricted hash
1b1f1335 221
49293501 222(F) The failing code has attempted to get or set a key which is not in
2393f1b9 223the current set of allowed keys of a restricted hash.
49293501 224
dcdfe746
FC
225=item Attempt to bless into a freed package
226
227(F) You wrote C<bless $foo> with one argument after somehow causing
228the current package to be freed. Perl cannot figure out what to
229do, so it throws up in hands in despair.
230
81689caa
HS
231=item Attempt to bless into a reference
232
233(F) The CLASSNAME argument to the bless() operator is expected to be
57dedab9 234the name of the package to bless the resulting object into. You've
81689caa
HS
235supplied instead a reference to something: perhaps you wrote
236
237 bless $self, $proto;
238
239when you intended
240
241 bless $self, ref($proto) || $proto;
242
243If you actually want to bless into the stringified version
244of the reference supplied, you need to stringify it yourself, for
245example by:
246
247 bless $self, "$proto";
248
a730510a
FC
249=item Attempt to clear deleted array
250
251(S debugging) An array was assigned to when it was being freed.
252Freed values are not supposed to be visible to Perl code. This
253can also happen if XS code calls C<av_clear> from a custom magic
254callback on the array.
255
96ebfdd7
RK
256=item Attempt to delete disallowed key '%s' from a restricted hash
257
258(F) The failing code attempted to delete from a restricted hash a key
259which is not in its key set.
260
261=item Attempt to delete readonly key '%s' from a restricted hash
262
263(F) The failing code attempted to delete a key whose value has been
264declared readonly from a restricted hash.
265
de42a5a9 266=item Attempt to free non-arena SV: 0x%x
a0d0e21e 267
f84fe999 268(S internal) All SV objects are supposed to be allocated from arenas
be771a83
GS
269that will be garbage collected on exit. An SV was discovered to be
270outside any of those arenas.
a0d0e21e 271
12578ffb 272=item Attempt to free nonexistent shared string '%s'%s
bbce6d69 273
f84fe999 274(S internal) Perl maintains a reference-counted internal table of
be771a83
GS
275strings to optimize the storage and access of hash keys and other
276strings. This indicates someone tried to decrement the reference count
277of a string that can no longer be found in the table.
bbce6d69 278
7d5b40b4 279=item Attempt to free temp prematurely: SV 0x%x
a0d0e21e 280
f84fe999 281(S debugging) Mortalized values are supposed to be freed by the
be771a83
GS
282free_tmps() routine. This indicates that something else is freeing the
283SV before the free_tmps() routine gets a chance, which means that the
284free_tmps() routine will be freeing an unreferenced scalar when it does
285try to free it.
a0d0e21e
LW
286
287=item Attempt to free unreferenced glob pointers
288
f84fe999 289(S internal) The reference counts got screwed up on symbol aliases.
a0d0e21e 290
7d5b40b4 291=item Attempt to free unreferenced scalar: SV 0x%x
a0d0e21e 292
8f7e4d2c 293(S internal) Perl went to decrement the reference count of a scalar to
be771a83
GS
294see if it would go to 0, and discovered that it had already gone to 0
295earlier, and should have been freed, and in fact, probably was freed.
296This could indicate that SvREFCNT_dec() was called too many times, or
297that SvREFCNT_inc() was called too few times, or that the SV was
298mortalized when it shouldn't have been, or that memory has been
299corrupted.
a0d0e21e 300
84902520
TB
301=item Attempt to pack pointer to temporary value
302
be771a83
GS
303(W pack) You tried to pass a temporary value (like the result of a
304function, or a computed expression) to the "p" pack() template. This
305means the result contains a pointer to a location that could become
306invalid anytime, even before the end of the current statement. Use
307literals or global values as arguments to the "p" pack() template to
308avoid this warning.
84902520 309
087b5369
RD
310=item Attempt to reload %s aborted.
311
312(F) You tried to load a file with C<use> or C<require> that failed to
313compile once already. Perl will not try to compile this file again
314unless you delete its entry from %INC. See L<perlfunc/require> and
315L<perlvar/%INC>.
316
1b20cd17
NC
317=item Attempt to set length of freed array
318
0c5c527f
FC
319(W misc) You tried to set the length of an array which has
320been freed. You can do this by storing a reference to the
321scalar representing the last index of an array and later
322assigning through that reference. For example
1b20cd17
NC
323
324 $r = do {my @a; \$#a};
325 $$r = 503
326
b7a902f4
PP
327=item Attempt to use reference as lvalue in substr
328
be771a83
GS
329(W substr) You supplied a reference as the first argument to substr()
330used as an lvalue, which is pretty strange. Perhaps you forgot to
331dereference it first. See L<perlfunc/substr>.
b7a902f4 332
c32124fe
NC
333=item Attribute "locked" is deprecated
334
57dedab9
FC
335(D deprecated) You have used the attributes pragma to modify the
336"locked" attribute on a code reference. The :locked attribute is
337obsolete, has had no effect since 5005 threads were removed, and
338will be removed in a future release of Perl 5.
c32124fe 339
591f5ca2
FC
340=item Attribute prototype(%s) discards earlier prototype attribute in same sub
341
342(W misc) A sub was declared as sub foo : prototype(A) : prototype(B) {}, for
343example. Since each sub can only have one prototype, the earlier
344declaration(s) are discarded while the last one is applied.
345
f1a3ce43
NC
346=item Attribute "unique" is deprecated
347
57dedab9
FC
348(D deprecated) You have used the attributes pragma to modify
349the "unique" attribute on an array, hash or scalar reference.
350The :unique attribute has had no effect since Perl 5.8.8, and
351will be removed in a future release of Perl 5.
f1a3ce43 352
ccce04a4
FC
353=item av_reify called on tied array
354
355(S debugging) This indicates that something went wrong and Perl got I<very>
356confused about C<@_> or C<@DB::args> being tied.
357
de42a5a9 358=item Bad arg length for %s, is %u, should be %d
a0d0e21e 359
be771a83
GS
360(F) You passed a buffer of the wrong size to one of msgctl(), semctl()
361or shmctl(). In C parlance, the correct sizes are, respectively,
5f05dabc 362S<sizeof(struct msqid_ds *)>, S<sizeof(struct semid_ds *)>, and
a0d0e21e
LW
363S<sizeof(struct shmid_ds *)>.
364
7a95317d
GS
365=item Bad evalled substitution pattern
366
496a33f5 367(F) You've used the C</e> switch to evaluate the replacement for a
7a95317d
GS
368substitution, but perl found a syntax error in the code to evaluate,
369most likely an unexpected right brace '}'.
370
a0d0e21e
LW
371=item Bad filehandle: %s
372
be771a83
GS
373(F) A symbol was passed to something wanting a filehandle, but the
374symbol has no filehandle associated with it. Perhaps you didn't do an
375open(), or did it in another package.
a0d0e21e
LW
376
377=item Bad free() ignored
378
be771a83 379(S malloc) An internal routine called free() on something that had never
fa816bf3 380been malloc()ed in the first place. Mandatory, but can be disabled by
9ea8bc6d 381setting environment variable C<PERL_BADFREE> to 0.
33c8a3fe 382
9ea8bc6d 383This message can be seen quite often with DB_File on systems with "hard"
6903afa2 384dynamic linking, like C<AIX> and C<OS/2>. It is a bug of C<Berkeley DB>
be771a83 385which is left unnoticed if C<DB> uses I<forgiving> system malloc().
a0d0e21e 386
aa689395
PP
387=item Bad hash
388
389(P) One of the internal hash routines was passed a null HV pointer.
390
6df41af2
GS
391=item Badly placed ()'s
392
393(A) You've accidentally run your script through B<csh> instead
394of Perl. Check the #! line, or manually feed your script into
395Perl yourself.
396
a7cb8dae 397=item Bad name after %s
a0d0e21e 398
be771a83
GS
399(F) You started to name a symbol by using a package prefix, and then
400didn't finish the symbol. In particular, you can't interpolate outside
401of quotes, so
a0d0e21e
LW
402
403 $var = 'myvar';
404 $sym = mypack::$var;
405
406is not the same as
407
408 $var = 'myvar';
409 $sym = "mypack::$var";
410
88e1f1a2
JV
411=item Bad plugin affecting keyword '%s'
412
413(F) An extension using the keyword plugin mechanism violated the
414plugin API.
415
4ad56ec9
IZ
416=item Bad realloc() ignored
417
6903afa2
FC
418(S malloc) An internal routine called realloc() on something that
419had never been malloc()ed in the first place. Mandatory, but can
420be disabled by setting the environment variable C<PERL_BADFREE> to 1.
4ad56ec9 421
a0d0e21e
LW
422=item Bad symbol for array
423
424(P) An internal request asked to add an array entry to something that
425wasn't a symbol table entry.
426
4df3f177
SP
427=item Bad symbol for dirhandle
428
429(P) An internal request asked to add a dirhandle entry to something
430that wasn't a symbol table entry.
431
a0d0e21e
LW
432=item Bad symbol for filehandle
433
be771a83
GS
434(P) An internal request asked to add a filehandle entry to something
435that wasn't a symbol table entry.
a0d0e21e
LW
436
437=item Bad symbol for hash
438
439(P) An internal request asked to add a hash entry to something that
440wasn't a symbol table entry.
441
34d09196
GS
442=item Bareword found in conditional
443
be771a83
GS
444(W bareword) The compiler found a bareword where it expected a
445conditional, which often indicates that an || or && was parsed as part
446of the last argument of the previous construct, for example:
34d09196
GS
447
448 open FOO || die;
449
be771a83
GS
450It may also indicate a misspelled constant that has been interpreted as
451a bareword:
34d09196
GS
452
453 use constant TYPO => 1;
454 if (TYOP) { print "foo" }
455
456The C<strict> pragma is useful in avoiding such errors.
457
6df41af2
GS
458=item Bareword "%s" not allowed while "strict subs" in use
459
460(F) With "strict subs" in use, a bareword is only allowed as a
be771a83
GS
461subroutine identifier, in curly brackets or to the left of the "=>"
462symbol. Perhaps you need to predeclare a subroutine?
6df41af2
GS
463
464=item Bareword "%s" refers to nonexistent package
465
be771a83
GS
466(W bareword) You used a qualified bareword of the form C<Foo::>, but the
467compiler saw no other uses of that namespace before that point. Perhaps
468you need to predeclare a package?
6df41af2 469
a0d0e21e
LW
470=item BEGIN failed--compilation aborted
471
be771a83
GS
472(F) An untrapped exception was raised while executing a BEGIN
473subroutine. Compilation stops immediately and the interpreter is
474exited.
a0d0e21e 475
68dc0745
PP
476=item BEGIN not safe after errors--compilation aborted
477
478(F) Perl found a C<BEGIN {}> subroutine (or a C<use> directive, which
be771a83
GS
479implies a C<BEGIN {}>) after one or more compilation errors had already
480occurred. Since the intended environment for the C<BEGIN {}> could not
481be guaranteed (due to the errors), and since subsequent code likely
482depends on its correct operation, Perl just gave up.
68dc0745 483
c782d7ee 484=item \%d better written as $%d
6df41af2 485
be771a83
GS
486(W syntax) Outside of patterns, backreferences live on as variables.
487The use of backslashes is grandfathered on the right-hand side of a
488substitution, but stylistically it's better to use the variable form
489because other Perl programmers will expect it, and it works better if
490there are more than 9 backreferences.
6df41af2 491
252aa082
JH
492=item Binary number > 0b11111111111111111111111111111111 non-portable
493
e476b1b5 494(W portable) The binary number you specified is larger than 2**32-1
9e24b6e2
JH
495(4294967295) and therefore non-portable between systems. See
496L<perlport> for more on portability concerns.
252aa082 497
69282e91 498=item bind() on closed socket %s
a0d0e21e 499
be771a83
GS
500(W closed) You tried to do a bind on a closed socket. Did you forget to
501check the return value of your socket() call? See L<perlfunc/bind>.
a0d0e21e 502
c289d2f7
JH
503=item binmode() on closed filehandle %s
504
505(W unopened) You tried binmode() on a filehandle that was never opened.
4dcecea4 506Check your control flow and number of arguments.
c289d2f7 507
c5a0f51a
JH
508=item Bit vector size > 32 non-portable
509
e476b1b5 510(W portable) Using bit vector sizes larger than 32 is non-portable.
c5a0f51a 511
043c750c 512=item Bizarre copy of %s
4633a7c4 513
be771a83 514(P) Perl detected an attempt to copy an internal value that is not
ab830aa0 515copiable.
4633a7c4 516
5a25739d
FC
517=item Bizarre SvTYPE [%d]
518
434f489b 519(P) When starting a new thread or returning values from a thread, Perl
5a25739d
FC
520encountered an invalid data type.
521
f675dbe5
CB
522=item Buffer overflow in prime_env_iter: %s
523
be771a83
GS
524(W internal) A warning peculiar to VMS. While Perl was preparing to
525iterate over %ENV, it encountered a logical name or symbol definition
526which was too long, so it was truncated to the string shown.
f675dbe5 527
a0d0e21e
LW
528=item Callback called exit
529
4929bf7b 530(F) A subroutine invoked from an external package via call_sv()
a0d0e21e
LW
531exited by calling exit.
532
6df41af2 533=item %s() called too early to check prototype
f675dbe5 534
be771a83
GS
535(W prototype) You've called a function that has a prototype before the
536parser saw a definition or declaration for it, and Perl could not check
537that the call conforms to the prototype. You need to either add an
538early prototype declaration for the subroutine in question, or move the
539subroutine definition ahead of the call to get proper prototype
540checking. Alternatively, if you are certain that you're calling the
541function correctly, you may put an ampersand before the name to avoid
542the warning. See L<perlsub>.
f675dbe5 543
56feebad
FC
544=item Calling POSIX::%s() is deprecated
545
546(D deprecated) You called a function whose use is deprecated. See
547the function's name in L<POSIX> for details.
548
49704364 549=item Cannot compress integer in pack
0258719b
NC
550
551(F) An argument to pack("w",...) was too large to compress. The BER
552compressed integer format can only be used with positive integers, and you
553attempted to compress Infinity or a very large number (> 1e308).
554See L<perlfunc/pack>.
555
49704364 556=item Cannot compress negative numbers in pack
0258719b
NC
557
558(F) An argument to pack("w",...) was negative. The BER compressed integer
559format can only be used with positive integers. See L<perlfunc/pack>.
560
5c1f4d79
NC
561=item Cannot convert a reference to %s to typeglob
562
6903afa2
FC
563(F) You manipulated Perl's symbol table directly, stored a reference
564in it, then tried to access that symbol via conventional Perl syntax.
565The access triggers Perl to autovivify that typeglob, but it there is
566no legal conversion from that type of reference to a typeglob.
5c1f4d79 567
4040665a 568=item Cannot copy to %s
ba2fdce6
NC
569
570(P) Perl detected an attempt to copy a value to an internal type that cannot
4dcecea4 571be directly assigned to.
ba2fdce6 572
b5d97229
RGS
573=item Cannot find encoding "%s"
574
575(S io) You tried to apply an encoding that did not exist to a filehandle,
576either with open() or binmode().
577
7355df7e
FC
578=item Cannot set tied @DB::args
579
580(F) C<caller> tried to set C<@DB::args>, but found it tied. Tying C<@DB::args>
581is not supported. (Before this error was added, it used to crash.)
582
ce65bc73
FC
583=item Cannot tie unreifiable array
584
585(P) You somehow managed to call C<tie> on an array that does not
586keep a reference count on its arguments and cannot be made to
587do so. Such arrays are not even supposed to be accessible to
588Perl code, but are only used internally.
589
96ebfdd7
RK
590=item Can only compress unsigned integers in pack
591
592(F) An argument to pack("w",...) was not an integer. The BER compressed
593integer format can only be used with positive integers, and you attempted
594to compress something else. See L<perlfunc/pack>.
595
a0d0e21e
LW
596=item Can't bless non-reference value
597
598(F) Only hard references may be blessed. This is how Perl "enforces"
599encapsulation of objects. See L<perlobj>.
600
dc57907a
RGS
601=item Can't "break" in a loop topicalizer
602
0d863452 603(F) You called C<break>, but you're in a C<foreach> block rather than
6903afa2 604a C<given> block. You probably meant to use C<next> or C<last>.
0d863452
RH
605
606=item Can't "break" outside a given block
dc57907a 607
0d863452
RH
608(F) You called C<break>, but you're not inside a C<given> block.
609
6df41af2
GS
610=item Can't call method "%s" on an undefined value
611
612(F) You used the syntax of a method call, but the slot filled by the
be771a83
GS
613object reference or package name contains an undefined value. Something
614like this will reproduce the error:
6df41af2
GS
615
616 $BADREF = undef;
617 process $BADREF 1,2,3;
618 $BADREF->process(1,2,3);
619
a0d0e21e
LW
620=item Can't call method "%s" on unblessed reference
621
54310121 622(F) A method call must know in what package it's supposed to run. It
be771a83
GS
623ordinarily finds this out from the object reference you supply, but you
624didn't supply an object reference in this case. A reference isn't an
625object reference until it has been blessed. See L<perlobj>.
a0d0e21e
LW
626
627=item Can't call method "%s" without a package or object reference
628
629(F) You used the syntax of a method call, but the slot filled by the
be771a83
GS
630object reference or package name contains an expression that returns a
631defined value which is neither an object reference nor a package name.
72b5445b
GS
632Something like this will reproduce the error:
633
634 $BADREF = 42;
635 process $BADREF 1,2,3;
636 $BADREF->process(1,2,3);
637
dfe378f1
FC
638=item Can't call mro_isa_changed_in() on anonymous symbol table
639
640(P) Perl got confused as to whether a hash was a plain hash or a
641symbol table hash when trying to update @ISA caches.
642
2bf7e7b2
FC
643=item Can't call mro_method_changed_in() on anonymous symbol table
644
645(F) An XS module tried to call C<mro_method_changed_in> on a hash that was
646not attached to the symbol table.
647
a0d0e21e
LW
648=item Can't chdir to %s
649
f703fc96 650(F) You called C<perl -x/foo/bar>, but F</foo/bar> is not a directory
a0d0e21e
LW
651that you can chdir to, possibly because it doesn't exist.
652
0545a864 653=item Can't check filesystem of script "%s" for nosuid
104d25b7 654
be771a83
GS
655(P) For some reason you can't check the filesystem of the script for
656nosuid.
104d25b7 657
22e74366 658=item Can't coerce %s to %s in %s
a0d0e21e
LW
659
660(F) Certain types of SVs, in particular real symbol table entries
55497cff 661(typeglobs), can't be forced to stop being what they are. So you can't
a0d0e21e
LW
662say things like:
663
664 *foo += 1;
665
666You CAN say
667
668 $foo = *foo;
669 $foo += 1;
670
671but then $foo no longer contains a glob.
672
0d863452 673=item Can't "continue" outside a when block
dc57907a 674
0d863452
RH
675(F) You called C<continue>, but you're not inside a C<when>
676or C<default> block.
677
a0d0e21e
LW
678=item Can't create pipe mailbox
679
be771a83
GS
680(P) An error peculiar to VMS. The process is suffering from exhausted
681quotas or other plumbing problems.
a0d0e21e 682
eb64745e
GS
683=item Can't declare %s in "%s"
684
30c282f6
NC
685(F) Only scalar, array, and hash variables may be declared as "my", "our" or
686"state" variables. They must have ordinary identifiers as names.
a0d0e21e 687
fc7debfb
FC
688=item Can't "default" outside a topicalizer
689
690(F) You have used a C<default> block that is neither inside a
691C<foreach> loop nor a C<given> block. (Note that this error is
692issued on exit from the C<default> block, so you won't get the
693error if you use an explicit C<continue>.)
694
6df41af2
GS
695=item Can't do inplace edit: %s is not a regular file
696
be771a83 697(S inplace) You tried to use the B<-i> switch on a special file, such as
df7075a8 698a file in /dev, a FIFO or an uneditable directory. The file was ignored.
6df41af2 699
a0d0e21e
LW
700=item Can't do inplace edit on %s: %s
701
be771a83
GS
702(S inplace) The creation of the new file failed for the indicated
703reason.
a0d0e21e 704
54310121 705=item Can't do inplace edit without backup
a0d0e21e 706
be771a83
GS
707(F) You're on a system such as MS-DOS that gets confused if you try
708reading from a deleted (but still opened) file. You have to say
709C<-i.bak>, or some such.
a0d0e21e 710
10f9c03d 711=item Can't do inplace edit: %s would not be unique
a0d0e21e 712
e476b1b5 713(S inplace) Your filesystem does not support filenames longer than 14
10f9c03d
CK
714characters and Perl was unable to create a unique filename during
715inplace editing with the B<-i> switch. The file was ignored.
a0d0e21e 716
a0d0e21e
LW
717=item Can't do waitpid with flags
718
be771a83
GS
719(F) This machine doesn't have either waitpid() or wait4(), so only
720waitpid() without flags is emulated.
a0d0e21e 721
a0d0e21e
LW
722=item Can't emulate -%s on #! line
723
be771a83
GS
724(F) The #! line specifies a switch that doesn't make sense at this
725point. For example, it'd be kind of silly to put a B<-x> on the #!
726line.
a0d0e21e 727
1109a392
MHM
728=item Can't %s %s-endian %ss on this platform
729
730(F) Your platform's byte-order is neither big-endian nor little-endian,
731or it has a very strange pointer size. Packing and unpacking big- or
732little-endian floating point values and pointers may not be possible.
733See L<perlfunc/pack>.
734
a0d0e21e
LW
735=item Can't exec "%s": %s
736
d1be9408 737(W exec) A system(), exec(), or piped open call could not execute the
be771a83
GS
738named program for the indicated reason. Typical reasons include: the
739permissions were wrong on the file, the file wasn't found in
740C<$ENV{PATH}>, the executable in question was compiled for another
741architecture, or the #! line in a script points to an interpreter that
742can't be run for similar reasons. (Or maybe your system doesn't support
743#! at all.)
a0d0e21e
LW
744
745=item Can't exec %s
746
be771a83
GS
747(F) Perl was trying to execute the indicated program for you because
748that's what the #! line said. If that's not what you wanted, you may
749need to mention "perl" on the #! line somewhere.
a0d0e21e
LW
750
751=item Can't execute %s
752
be771a83
GS
753(F) You used the B<-S> switch, but the copies of the script to execute
754found in the PATH did not have correct permissions.
2a92aaa0 755
6df41af2 756=item Can't find an opnumber for "%s"
2a92aaa0 757
be771a83
GS
758(F) A string of a form C<CORE::word> was given to prototype(), but there
759is no builtin with the name C<word>.
6df41af2 760
56ca2fc0
JH
761=item Can't find %s character property "%s"
762
763(F) You used C<\p{}> or C<\P{}> but the character property by that name
6903afa2 764could not be found. Maybe you misspelled the name of the property?
e1b711da 765See L<perluniprops/Properties accessible through \p{} and \P{}>
9b73678d 766for a complete list of available official properties.
56ca2fc0 767
6df41af2
GS
768=item Can't find label %s
769
be771a83
GS
770(F) You said to goto a label that isn't mentioned anywhere that it's
771possible for us to go to. See L<perlfunc/goto>.
2a92aaa0
GS
772
773=item Can't find %s on PATH
774
be771a83
GS
775(F) You used the B<-S> switch, but the script to execute could not be
776found in the PATH.
a0d0e21e 777
6df41af2 778=item Can't find %s on PATH, '.' not in PATH
a0d0e21e 779
be771a83
GS
780(F) You used the B<-S> switch, but the script to execute could not be
781found in the PATH, or at least not with the correct permissions. The
782script exists in the current directory, but PATH prohibits running it.
a0d0e21e
LW
783
784=item Can't find string terminator %s anywhere before EOF
785
be771a83
GS
786(F) Perl strings can stretch over multiple lines. This message means
787that the closing delimiter was omitted. Because bracketed quotes count
788nesting levels, the following is missing its final parenthesis:
a0d0e21e 789
fb73857a
PP
790 print q(The character '(' starts a side comment.);
791
97b3d10f 792If you're getting this error from a here-document, you may have
b6b8cb97
FC
793included unseen whitespace before or after your closing tag or there
794may not be a linebreak after it. A good programmer's editor will have
795a way to help you find these characters (or lack of characters). See
796L<perlop> for the full details on here-documents.
a0d0e21e 797
660a4616
ST
798=item Can't find Unicode property definition "%s"
799
5f8ad6b6
FC
800(F) You may have tried to use C<\p> which means a Unicode
801property (for example C<\p{Lu}> matches all uppercase
fa816bf3 802letters). If you did mean to use a Unicode property, see
e1b711da 803L<perluniprops/Properties accessible through \p{} and \P{}>
6903afa2 804for a complete list of available properties. If you didn't
fa816bf3
FC
805mean to use a Unicode property, escape the C<\p>, either by
806C<\\p> (just the C<\p>) or by C<\Q\p> (the rest of the string, or
5f8ad6b6 807until C<\E>).
660a4616 808
b3647a36 809=item Can't fork: %s
a0d0e21e 810
be771a83
GS
811(F) A fatal error occurred while trying to fork while opening a
812pipeline.
a0d0e21e 813
b3647a36
SR
814=item Can't fork, trying again in 5 seconds
815
c973c02e 816(W pipe) A fork in a piped open failed with EAGAIN and will be retried
b3647a36
SR
817after five seconds.
818
748a9306
LW
819=item Can't get filespec - stale stat buffer?
820
be771a83
GS
821(S) A warning peculiar to VMS. This arises because of the difference
822between access checks under VMS and under the Unix model Perl assumes.
823Under VMS, access checks are done by filename, rather than by bits in
824the stat buffer, so that ACLs and other protections can be taken into
825account. Unfortunately, Perl assumes that the stat buffer contains all
826the necessary information, and passes it, instead of the filespec, to
2fe2bdfd 827the access-checking routine. It will try to retrieve the filespec using
be771a83
GS
828the device name and FID present in the stat buffer, but this works only
829if you haven't made a subsequent call to the CRTL stat() routine,
830because the device name is overwritten with each call. If this warning
2fe2bdfd
FC
831appears, the name lookup failed, and the access-checking routine gave up
832and returned FALSE, just to be conservative. (Note: The access-checking
be771a83
GS
833routine knows about the Perl C<stat> operator and file tests, so you
834shouldn't ever see this warning in response to a Perl command; it arises
835only if some internal code takes stat buffers lightly.)
748a9306 836
a0d0e21e
LW
837=item Can't get pipe mailbox device name
838
be771a83
GS
839(P) An error peculiar to VMS. After creating a mailbox to act as a
840pipe, Perl can't retrieve its name for later use.
a0d0e21e
LW
841
842=item Can't get SYSGEN parameter value for MAXBUF
843
748a9306
LW
844(P) An error peculiar to VMS. Perl asked $GETSYI how big you want your
845mailbox buffers to be, and didn't get an answer.
a0d0e21e 846
6df41af2 847=item Can't "goto" into the middle of a foreach loop
a0d0e21e 848
be771a83
GS
849(F) A "goto" statement was executed to jump into the middle of a foreach
850loop. You can't get there from here. See L<perlfunc/goto>.
6df41af2
GS
851
852=item Can't "goto" out of a pseudo block
853
be771a83
GS
854(F) A "goto" statement was executed to jump out of what might look like
855a block, except that it isn't a proper block. This usually occurs if
856you tried to jump out of a sort() block or subroutine, which is a no-no.
857See L<perlfunc/goto>.
a0d0e21e 858
5a25739d
FC
859=item Can't goto subroutine from an eval-%s
860
861(F) The "goto subroutine" call can't be used to jump out of an eval
862"string" or block.
863
9850bf21 864=item Can't goto subroutine from a sort sub (or similar callback)
cd299c6e 865
9850bf21
RH
866(F) The "goto subroutine" call can't be used to jump out of the
867comparison sub for a sort(), or from a similar callback (such
868as the reduce() function in List::Util).
869
6df41af2
GS
870=item Can't goto subroutine outside a subroutine
871
be771a83
GS
872(F) The deeply magical "goto subroutine" call can only replace one
873subroutine call for another. It can't manufacture one out of whole
874cloth. In general you should be calling it out of only an AUTOLOAD
875routine anyway. See L<perlfunc/goto>.
6df41af2 876
0b5b802d
GS
877=item Can't ignore signal CHLD, forcing to default
878
be771a83
GS
879(W signal) Perl has detected that it is being run with the SIGCHLD
880signal (sometimes known as SIGCLD) disabled. Since disabling this
881signal will interfere with proper determination of exit status of child
882processes, Perl has reset the signal to its default value. This
883situation typically indicates that the parent program under which Perl
884may be running (e.g. cron) is being very careless.
0b5b802d 885
e2c0f81f
DG
886=item Can't kill a non-numeric process ID
887
888(F) Process identifiers must be (signed) integers. It is a fatal error to
889attempt to kill() an undefined, empty-string or otherwise non-numeric
890process identifier.
891
6df41af2 892=item Can't "last" outside a loop block
4633a7c4 893
6df41af2 894(F) A "last" statement was executed to break out of the current block,
be771a83
GS
895except that there's this itty bitty problem called there isn't a current
896block. Note that an "if" or "else" block doesn't count as a "loopish"
897block, as doesn't a block given to sort(), map() or grep(). You can
898usually double the curlies to get the same effect though, because the
899inner curlies will be considered a block that loops once. See
900L<perlfunc/last>.
4633a7c4 901
2c7d6b9c
RGS
902=item Can't linearize anonymous symbol table
903
904(F) Perl tried to calculate the method resolution order (MRO) of a
905package, but failed because the package stash has no name.
906
b8170e59
JB
907=item Can't load '%s' for module %s
908
6903afa2
FC
909(F) The module you tried to load failed to load a dynamic extension.
910This may either mean that you upgraded your version of perl to one
911that is incompatible with your old dynamic extensions (which is known
912to happen between major versions of perl), or (more likely) that your
913dynamic extension was built against an older version of the library
914that is installed on your system. You may need to rebuild your old
915dynamic extensions.
b8170e59 916
748a9306
LW
917=item Can't localize lexical variable %s
918
2ba9eb46 919(F) You used local on a variable name that was previously declared as a
b7e4ecc1
FC
920lexical variable using "my" or "state". This is not allowed. If you
921want to localize a package variable of the same name, qualify it with
922the package name.
748a9306 923
6df41af2 924=item Can't localize through a reference
4727527e 925
6df41af2
GS
926(F) You said something like C<local $$ref>, which Perl can't currently
927handle, because when it goes to restore the old value of whatever $ref
be771a83 928pointed to after the scope of the local() is finished, it can't be sure
64977eb6 929that $ref will still be a reference.
4727527e 930
ea071790 931=item Can't locate %s
ec889f3a 932
fa816bf3
FC
933(F) You said to C<do> (or C<require>, or C<use>) a file that couldn't be found.
934Perl looks for the file in all the locations mentioned in @INC, unless
935the file name included the full path to the file. Perhaps you need
936to set the PERL5LIB or PERL5OPT environment variable to say where the
937extra library is, or maybe the script needs to add the library name
be771a83
GS
938to @INC. Or maybe you just misspelled the name of the file. See
939L<perlfunc/require> and L<lib>.
a0d0e21e 940
6df41af2
GS
941=item Can't locate auto/%s.al in @INC
942
be771a83
GS
943(F) A function (or method) was called in a package which allows
944autoload, but there is no function to autoload. Most probable causes
945are a misprint in a function/method name or a failure to C<AutoSplit>
946the file, say, by doing C<make install>.
6df41af2 947
b8170e59
JB
948=item Can't locate loadable object for module %s in @INC
949
950(F) The module you loaded is trying to load an external library, like
d70d8e57 951for example, F<foo.so> or F<bar.dll>, but the L<DynaLoader> module was
b8170e59
JB
952unable to locate this library. See L<DynaLoader>.
953
a0d0e21e
LW
954=item Can't locate object method "%s" via package "%s"
955
956(F) You called a method correctly, and it correctly indicated a package
957functioning as a class, but that package doesn't define that particular
2ba9eb46 958method, nor does any of its base classes. See L<perlobj>.
a0d0e21e
LW
959
960=item Can't locate package %s for @%s::ISA
961
be771a83
GS
962(W syntax) The @ISA array contained the name of another package that
963doesn't seem to exist.
a0d0e21e 964
2f7da168
RK
965=item Can't locate PerlIO%s
966
967(F) You tried to use in open() a PerlIO layer that does not exist,
968e.g. open(FH, ">:nosuchlayer", "somefile").
969
f4ad53f4 970=item Can't make list assignment to %ENV on this system
3e3baf6d 971
be771a83
GS
972(F) List assignment to %ENV is not supported on some systems, notably
973VMS.
3e3baf6d 974
cd40cd58
NC
975=item Can't make loaded symbols global on this platform while loading %s
976
ff9c1ae8 977(S) A module passed the flag 0x01 to DynaLoader::dl_load_file() to request
cd40cd58
NC
978that symbols from the stated file are made available globally within the
979process, but that functionality is not available on this platform. Whilst
980the module likely will still work, this may prevent the perl interpreter
981from loading other XS-based extensions which need to link directly to
982functions defined in the C or XS code in the stated file.
983
a0d0e21e
LW
984=item Can't modify %s in %s
985
be771a83
GS
986(F) You aren't allowed to assign to the item indicated, or otherwise try
987to change it, such as with an auto-increment.
a0d0e21e 988
54310121 989=item Can't modify nonexistent substring
a0d0e21e
LW
990
991(P) The internal routine that does assignment to a substr() was handed
992a NULL.
993
6df41af2
GS
994=item Can't modify non-lvalue subroutine call
995
996(F) Subroutines meant to be used in lvalue context should be declared as
2fe2bdfd 997such. See L<perlsub/"Lvalue subroutines">.
6df41af2 998
5f05dabc 999=item Can't msgrcv to read-only var
a0d0e21e 1000
5f05dabc 1001(F) The target of a msgrcv must be modifiable to be used as a receive
a0d0e21e
LW
1002buffer.
1003
6df41af2
GS
1004=item Can't "next" outside a loop block
1005
1006(F) A "next" statement was executed to reiterate the current block, but
1007there isn't a current block. Note that an "if" or "else" block doesn't
be771a83
GS
1008count as a "loopish" block, as doesn't a block given to sort(), map() or
1009grep(). You can usually double the curlies to get the same effect
1010though, because the inner curlies will be considered a block that loops
1011once. See L<perlfunc/next>.
6df41af2 1012
a0d0e21e
LW
1013=item Can't open %s: %s
1014
c47ff5f1 1015(S inplace) The implicit opening of a file through use of the C<< <> >>
08e9d68e 1016filehandle, either implicitly under the C<-n> or C<-p> command-line
46fa9b26
FC
1017switches, or explicitly, failed for the indicated reason. Usually
1018this is because you don't have read permission for a file which
1019you named on the command line.
1020
1021(F) You tried to call perl with the B<-e> switch, but F</dev/null> (or
1022your operating system's equivalent) could not be opened.
a0d0e21e 1023
9a869a14
RGS
1024=item Can't open a reference
1025
1026(W io) You tried to open a scalar reference for reading or writing,
2fe2bdfd 1027using the 3-arg open() syntax:
9a869a14
RGS
1028
1029 open FH, '>', $ref;
1030
1031but your version of perl is compiled without perlio, and this form of
1032open is not supported.
1033
a0d0e21e
LW
1034=item Can't open bidirectional pipe
1035
be771a83
GS
1036(W pipe) You tried to say C<open(CMD, "|cmd|")>, which is not supported.
1037You can try any of several modules in the Perl library to do this, such
1038as IPC::Open2. Alternately, direct the pipe's output to a file using
1039">", and then read it in under a different file handle.
a0d0e21e 1040
748a9306
LW
1041=item Can't open error file %s as stderr
1042
be771a83
GS
1043(F) An error peculiar to VMS. Perl does its own command line
1044redirection, and couldn't open the file specified after '2>' or '2>>' on
1045the command line for writing.
748a9306
LW
1046
1047=item Can't open input file %s as stdin
1048
be771a83
GS
1049(F) An error peculiar to VMS. Perl does its own command line
1050redirection, and couldn't open the file specified after '<' on the
1051command line for reading.
748a9306
LW
1052
1053=item Can't open output file %s as stdout
1054
be771a83
GS
1055(F) An error peculiar to VMS. Perl does its own command line
1056redirection, and couldn't open the file specified after '>' or '>>' on
1057the command line for writing.
748a9306
LW
1058
1059=item Can't open output pipe (name: %s)
1060
be771a83
GS
1061(P) An error peculiar to VMS. Perl does its own command line
1062redirection, and couldn't open the pipe into which to send data destined
1063for stdout.
748a9306 1064
3b1cf97d 1065=item Can't open perl script "%s": %s
a0d0e21e
LW
1066
1067(F) The script you specified can't be opened for the indicated reason.
1068
fa3aa65a
JC
1069If you're debugging a script that uses #!, and normally relies on the
1070shell's $PATH search, the -S option causes perl to do that search, so
1071you don't have to type the path or C<`which $scriptname`>.
1072
6df41af2
GS
1073=item Can't read CRTL environ
1074
1075(S) A warning peculiar to VMS. Perl tried to read an element of %ENV
1076from the CRTL's internal environment array and discovered the array was
1077missing. You need to figure out where your CRTL misplaced its environ
be771a83
GS
1078or define F<PERL_ENV_TABLES> (see L<perlvms>) so that environ is not
1079searched.
6df41af2 1080
6df41af2
GS
1081=item Can't "redo" outside a loop block
1082
1083(F) A "redo" statement was executed to restart the current block, but
1084there isn't a current block. Note that an "if" or "else" block doesn't
1085count as a "loopish" block, as doesn't a block given to sort(), map()
1086or grep(). You can usually double the curlies to get the same effect
1087though, because the inner curlies will be considered a block that
1088loops once. See L<perlfunc/redo>.
1089
64977eb6 1090=item Can't remove %s: %s, skipping file
10f9c03d 1091
be771a83
GS
1092(S inplace) You requested an inplace edit without creating a backup
1093file. Perl was unable to remove the original file to replace it with
1094the modified file. The file was left unmodified.
10f9c03d 1095
a0d0e21e
LW
1096=item Can't rename %s to %s: %s, skipping file
1097
e476b1b5 1098(S inplace) The rename done by the B<-i> switch failed for some reason,
10f9c03d 1099probably because you don't have write permission to the directory.
a0d0e21e 1100
748a9306
LW
1101=item Can't reopen input pipe (name: %s) in binary mode
1102
be771a83
GS
1103(P) An error peculiar to VMS. Perl thought stdin was a pipe, and tried
1104to reopen it to accept binary data. Alas, it failed.
748a9306 1105
4f12ec0e
FC
1106=item Can't reset %ENV on this system
1107
1108(F) You called C<reset('E')> or similar, which tried to reset
1109all variables in the current package beginning with "E". In
1110the main package, that includes %ENV. Resetting %ENV is not
1111supported on some systems, notably VMS.
1112
fe13d51d 1113=item Can't resolve method "%s" overloading "%s" in package "%s"
6df41af2 1114
1fa582fa
FC
1115(F)(P) Error resolving overloading specified by a method name (as
1116opposed to a subroutine reference): no such method callable via the
1117package. If the method name is C<???>, this is an internal error.
6df41af2 1118
cd06dffe
GS
1119=item Can't return %s from lvalue subroutine
1120
be771a83
GS
1121(F) Perl detected an attempt to return illegal lvalues (such as
1122temporary or readonly values) from a subroutine used as an lvalue. This
1123is not allowed.
cd06dffe 1124
96ebfdd7
RK
1125=item Can't return outside a subroutine
1126
1127(F) The return statement was executed in mainline code, that is, where
1128there was no subroutine call to return out of. See L<perlsub>.
1129
78f9721b
SM
1130=item Can't return %s to lvalue scalar context
1131
6903afa2
FC
1132(F) You tried to return a complete array or hash from an lvalue
1133subroutine, but you called the subroutine in a way that made Perl
1134think you meant to return only one value. You probably meant to
1135write parentheses around the call to the subroutine, which tell
1136Perl that the call should be in list context.
78f9721b 1137
a0d0e21e
LW
1138=item Can't stat script "%s"
1139
be771a83
GS
1140(P) For some reason you can't fstat() the script even though you have it
1141open already. Bizarre.
a0d0e21e 1142
a0d0e21e
LW
1143=item Can't take log of %g
1144
fb73857a 1145(F) For ordinary real numbers, you can't take the logarithm of a
6903afa2 1146negative number or zero. There's a Math::Complex package that comes
be771a83
GS
1147standard with Perl, though, if you really want to do that for the
1148negative numbers.
a0d0e21e
LW
1149
1150=item Can't take sqrt of %g
1151
1152(F) For ordinary real numbers, you can't take the square root of a
fb73857a
PP
1153negative number. There's a Math::Complex package that comes standard
1154with Perl, though, if you really want to do that.
a0d0e21e
LW
1155
1156=item Can't undef active subroutine
1157
1158(F) You can't undefine a routine that's currently running. You can,
1159however, redefine it while it's running, and you can even undef the
1160redefined subroutine while the old routine is running. Go figure.
1161
c81225bc 1162=item Can't upgrade %s (%d) to %d
a0d0e21e 1163
be771a83
GS
1164(P) The internal sv_upgrade routine adds "members" to an SV, making it
1165into a more specialized kind of SV. The top several SV types are so
1166specialized, however, that they cannot be interconverted. This message
1167indicates that such a conversion was attempted.
a0d0e21e 1168
6651ba0b
FC
1169=item Can't use '%c' after -mname
1170
1171(F) You tried to call perl with the B<-m> switch, but you put something
1172other than "=" after the module name.
1173
1f1ec7b5
KW
1174=item Can't use a hash as a reference
1175
1176(F) You tried to use a hash as a reference, as in
66a1f5ec
FC
1177C<< %foo->{"bar"} >> or C<< %$ref->{"hello"} >>. Versions of perl
1178<= 5.22.0 used to allow this syntax, but shouldn't
1179have. This was deprecated in perl 5.6.1.
1f1ec7b5
KW
1180
1181=item Can't use an array as a reference
1182
1183(F) You tried to use an array as a reference, as in
66a1f5ec
FC
1184C<< @foo->[23] >> or C<< @$ref->[99] >>. Versions of perl <= 5.22.0
1185used to allow this syntax, but shouldn't have. This
1186was deprecated in perl 5.6.1.
1f1ec7b5 1187
1db89ea5
BS
1188=item Can't use anonymous symbol table for method lookup
1189
e27ad1f2 1190(F) The internal routine that does method lookup was handed a symbol
1db89ea5
BS
1191table that doesn't have a name. Symbol tables can become anonymous
1192for example by undefining stashes: C<undef %Some::Package::>.
1193
96ebfdd7
RK
1194=item Can't use an undefined value as %s reference
1195
1196(F) A value used as either a hard reference or a symbolic reference must
1197be a defined value. This helps to delurk some insidious errors.
1198
6df41af2
GS
1199=item Can't use bareword ("%s") as %s ref while "strict refs" in use
1200
be771a83
GS
1201(F) Only hard references are allowed by "strict refs". Symbolic
1202references are disallowed. See L<perlref>.
6df41af2 1203
90b75b61 1204=item Can't use %! because Errno.pm is not available
1d2dff63 1205
20561843 1206(F) The first time the C<%!> hash is used, perl automatically loads the
6903afa2 1207Errno.pm module. The Errno module is expected to tie the %! hash to
1d2dff63
GS
1208provide symbolic names for C<$!> errno values.
1209
1109a392
MHM
1210=item Can't use both '<' and '>' after type '%c' in %s
1211
1212(F) A type cannot be forced to have both big-endian and little-endian
1213byte-order at the same time, so this combination of modifiers is not
1214allowed. See L<perlfunc/pack>.
1215
e35475de
KW
1216=item Can't use 'defined(@array)' (Maybe you should just omit the defined()?)
1217
1218(F) defined() is not useful on arrays because it
1219checks for an undefined I<scalar> value. If you want to see if the
1220array is empty, just use C<if (@array) { # not empty }> for example.
1221
1222=item Can't use 'defined(%hash)' (Maybe you should just omit the defined()?)
1223
1224(F) C<defined()> is not usually right on hashes.
1225
1226Although C<defined %hash> is false on a plain not-yet-used hash, it
1227becomes true in several non-obvious circumstances, including iterators,
1228weak references, stash names, even remaining true after C<undef %hash>.
1229These things make C<defined %hash> fairly useless in practice, so it now
1230generates a fatal error.
1231
1232If a check for non-empty is what you wanted then just put it in boolean
1233context (see L<perldata/Scalar values>):
1234
1235 if (%hash) {
1236 # not empty
1237 }
1238
1239If you had C<defined %Foo::Bar::QUUX> to check whether such a package
1240variable exists then that's never really been reliable, and isn't
1241a good way to enquire about the features of a package, or whether
1242it's loaded, etc.
1243
6df41af2
GS
1244=item Can't use %s for loop variable
1245
be771a83
GS
1246(F) Only a simple scalar variable may be used as a loop variable on a
1247foreach.
6df41af2 1248
aab6a793 1249=item Can't use global %s in "%s"
6df41af2 1250
be771a83
GS
1251(F) You tried to declare a magical variable as a lexical variable. This
1252is not allowed, because the magic can be tied to only one location
1253(namely the global variable) and it would be incredibly confusing to
1254have variables in your program that looked like magical variables but
6df41af2
GS
1255weren't.
1256
6d3b25aa
RGS
1257=item Can't use '%c' in a group with different byte-order in %s
1258
1259(F) You attempted to force a different byte-order on a type
1260that is already inside a group with a byte-order modifier.
1261For example you cannot force little-endianness on a type that
1262is inside a big-endian group.
1263
c07a80fd
PP
1264=item Can't use "my %s" in sort comparison
1265
1266(F) The global variables $a and $b are reserved for sort comparisons.
c47ff5f1 1267You mentioned $a or $b in the same line as the <=> or cmp operator,
c07a80fd
PP
1268and the variable had earlier been declared as a lexical variable.
1269Either qualify the sort variable with the package name, or rename the
1270lexical variable.
1271
a0d0e21e
LW
1272=item Can't use %s ref as %s ref
1273
1274(F) You've mixed up your reference types. You have to dereference a
1275reference of the type needed. You can use the ref() function to
1276test the type of the reference, if need be.
1277
748a9306 1278=item Can't use string ("%s") as %s ref while "strict refs" in use
a0d0e21e 1279
5e634d20
FC
1280=item Can't use string ("%s"...) as %s ref while "strict refs" in use
1281
b41bf23f
FC
1282(F) You've told Perl to dereference a string, something which
1283C<use strict> blocks to prevent it happening accidentally. See
1284L<perlref/"Symbolic references">. This can be triggered by an C<@> or C<$>
1285in a double-quoted string immediately before interpolating a variable,
1286for example in C<"user @$twitter_id">, which says to treat the contents
1287of C<$twitter_id> as an array reference; use a C<\> to have a literal C<@>
1288symbol followed by the contents of C<$twitter_id>: C<"user \@$twitter_id">.
a0d0e21e 1289
748a9306
LW
1290=item Can't use subscript on %s
1291
1292(F) The compiler tried to interpret a bracketed expression as a
1293subscript. But to the left of the brackets was an expression that
209e7cf1 1294didn't look like a hash or array reference, or anything else subscriptable.
748a9306 1295
6df41af2
GS
1296=item Can't use \%c to mean $%c in expression
1297
75b44862
GS
1298(W syntax) In an ordinary expression, backslash is a unary operator that
1299creates a reference to its argument. The use of backslash to indicate a
1300backreference to a matched substring is valid only as part of a regular
be771a83
GS
1301expression pattern. Trying to do this in ordinary Perl code produces a
1302value that prints out looking like SCALAR(0xdecaf). Use the $1 form
1303instead.
6df41af2 1304
810b8aa5
GS
1305=item Can't weaken a nonreference
1306
1307(F) You attempted to weaken something that was not a reference. Only
1308references can be weakened.
1309
fc7debfb
FC
1310=item Can't "when" outside a topicalizer
1311
1312(F) You have used a when() block that is neither inside a C<foreach>
1313loop nor a C<given> block. (Note that this error is issued on exit
1314from the C<when> block, so you won't get the error if the match fails,
1315or if you use an explicit C<continue>.)
1316
5f05dabc 1317=item Can't x= to read-only value
a0d0e21e 1318
be771a83
GS
1319(F) You tried to repeat a constant value (often the undefined value)
1320with an assignment operator, which implies modifying the value itself.
a0d0e21e
LW
1321Perhaps you need to copy the value to a temporary, and repeat that.
1322
a04e6aad 1323=item Character following "\c" must be printable ASCII
f9d13529 1324
7357bd17 1325(F) In C<\cI<X>>, I<X> must be a printable (non-control) ASCII character.
17a3df4c 1326
727b6379 1327Note that ASCII characters that don't map to control characters are
7357bd17 1328discouraged, and will generate the warning (when enabled)
727b6379 1329L</""\c%c" is more clearly written simply as "%s"">.
f9d13529 1330
1f4ef0f1
JH
1331=item Character in 'C' format overflow in pack
1332
1333(W pack) You tried converting an infinity or not-a-number to an
1334unsigned character, which makes no sense. Perl behaved as if you
1335tried to pack 0xFF.
1336
f337b084 1337=item Character in 'C' format wrapped in pack
ac7cd81a
SC
1338
1339(W pack) You said
1340
1341 pack("C", $x)
1342
1343where $x is either less than 0 or more than 255; the C<"C"> format is
1344only for encoding native operating system characters (ASCII, EBCDIC,
1345and so on) and not for Unicode characters, so Perl behaved as if you meant
1346
1347 pack("C", $x & 255)
1348
1349If you actually want to pack Unicode codepoints, use the C<"U"> format
1350instead.
1351
1f4ef0f1
JH
1352=item Character in 'c' format overflow in pack
1353
1354(W pack) You tried converting an infinity or not-a-number to a
1355signed character, which makes no sense. Perl behaved as if you
1356tried to pack 0xFF.
1357
f337b084 1358=item Character in 'c' format wrapped in pack
ac7cd81a
SC
1359
1360(W pack) You said
1361
1362 pack("c", $x)
1363
1364where $x is either less than -128 or more than 127; the C<"c"> format
1365is only for encoding native operating system characters (ASCII, EBCDIC,
1366and so on) and not for Unicode characters, so Perl behaved as if you meant
1367
1368 pack("c", $x & 255);
1369
1370If you actually want to pack Unicode codepoints, use the C<"U"> format
1371instead.
1372
f337b084
TH
1373=item Character in '%c' format wrapped in unpack
1374
1375(W unpack) You tried something like
1376
1377 unpack("H", "\x{2a1}")
1378
1a147d38 1379where the format expects to process a byte (a character with a value
6903afa2
FC
1380below 256), but a higher value was provided instead. Perl uses the
1381value modulus 256 instead, as if you had provided:
f337b084
TH
1382
1383 unpack("H", "\x{a1}")
1384
5a25739d
FC
1385=item Character in 'W' format wrapped in pack
1386
1387(W pack) You said
1388
1389 pack("U0W", $x)
1390
1391where $x is either less than 0 or more than 255. However, C<U0>-mode
1392expects all values to fall in the interval [0, 255], so Perl behaved
1393as if you meant:
1394
1395 pack("U0W", $x & 255)
1396
f337b084
TH
1397=item Character(s) in '%c' format wrapped in pack
1398
1399(W pack) You tried something like
1400
1401 pack("u", "\x{1f3}b")
1402
1a147d38 1403where the format expects to process a sequence of bytes (character with a
6903afa2 1404value below 256), but some of the characters had a higher value. Perl
f337b084
TH
1405uses the character values modulus 256 instead, as if you had provided:
1406
1407 pack("u", "\x{f3}b")
1408
1409=item Character(s) in '%c' format wrapped in unpack
1410
1411(W unpack) You tried something like
1412
1413 unpack("s", "\x{1f3}b")
1414
1a147d38 1415where the format expects to process a sequence of bytes (character with a
6903afa2 1416value below 256), but some of the characters had a higher value. Perl
f337b084
TH
1417uses the character values modulus 256 instead, as if you had provided:
1418
1419 unpack("s", "\x{f3}b")
1420
f51551f7
FC
1421=item charnames alias definitions may not contain a sequence of multiple spaces
1422
1423(F) You defined a character name which had multiple space characters
1424in a row. Change them to single spaces. Usually these names are
1425defined in the C<:alias> import argument to C<use charnames>, but they
1426could be defined by a translator installed into C<$^H{charnames}>. See
1427L<charnames/CUSTOM ALIASES>.
1428
1429=item charnames alias definitions may not contain trailing white-space
1430
1431(F) You defined a character name which ended in a space
1432character. Remove the trailing space(s). Usually these names are
1433defined in the C<:alias> import argument to C<use charnames>, but they
1434could be defined by a translator installed into C<$^H{charnames}>.
1435See L<charnames/CUSTOM ALIASES>.
1436
1437=item \C is deprecated in regex; marked by <-- HERE in m/%s/
1438
1439(D deprecated, regexp) The \C character class is deprecated, and will
1440become a compile-time error in a future release of perl (tentatively
1441v5.24). This construct allows you to match a single byte of what makes up
1442a multi-byte single UTF8 character, and breaks encapsulation. It is
1443currently also very buggy. If you really need to process the individual
1444bytes, you probably want to convert your string to one where each
1445underlying byte is stored as a character, with utf8::encode().
1446
f866a7cd
FC
1447=item "\c%c" is more clearly written simply as "%s"
1448
1449(W syntax) The C<\cI<X>> construct is intended to be a way to specify
7ed0dd93
FC
1450non-printable characters. You used it for a printable one, which
1451is better written as simply itself, perhaps preceded by a backslash
1452for non-word characters. Doing it the way you did is not portable
1453between ASCII and EBCDIC platforms.
f866a7cd 1454
6651ba0b
FC
1455=item Cloning substitution context is unimplemented
1456
1457(F) Creating a new thread inside the C<s///> operator is not supported.
1458
abc7ecad
SP
1459=item closedir() attempted on invalid dirhandle %s
1460
1461(W io) The dirhandle you tried to close is either closed or not really
1462a dirhandle. Check your control flow.
1463
5a25739d
FC
1464=item close() on unopened filehandle %s
1465
1466(W unopened) You tried to close a filehandle that was never opened.
1467
541ed3a9
FC
1468=item Closure prototype called
1469
1470(F) If a closure has attributes, the subroutine passed to an attribute
1471handler is the prototype that is cloned when a new closure is created.
1472This subroutine cannot be called.
1473
49704364
LW
1474=item Code missing after '/'
1475
6903afa2
FC
1476(F) You had a (sub-)template that ends with a '/'. There must be
1477another template code following the slash. See L<perlfunc/pack>.
49704364 1478
5a25739d
FC
1479=item Code point 0x%X is not Unicode, may not be portable
1480
2d88a86a 1481(S non_unicode) You had a code point above the Unicode maximum
1b64326b
FC
1482of U+10FFFF.
1483
1484Perl allows strings to contain a superset of Unicode code points, up
1485to the limit of what is storable in an unsigned integer on your system,
1486but these may not be accepted by other languages/systems. At one time,
1487it was legal in some standards to have code points up to 0x7FFF_FFFF,
1488but not higher. Code points above 0xFFFF_FFFF require larger than a
148932 bit word.
0876b9a0 1490
6df41af2
GS
1491=item %s: Command not found
1492
a892b81a 1493(A) You've accidentally run your script through B<csh> or another shell
66a1f5ec
FC
1494instead of Perl. Check the #! line, or manually feed your script into
1495Perl yourself. The #! line at the top of your file could look like
8f721816
MM
1496
1497 #!/usr/bin/perl -w
6df41af2 1498
7a2e2cd6
PP
1499=item Compilation failed in require
1500
1501(F) Perl could not compile a file specified in a C<require> statement.
be771a83
GS
1502Perl uses this generic message when none of the errors that it
1503encountered were severe enough to halt compilation immediately.
7a2e2cd6 1504
c3464db5
DD
1505=item Complex regular subexpression recursion limit (%d) exceeded
1506
be771a83
GS
1507(W regexp) The regular expression engine uses recursion in complex
1508situations where back-tracking is required. Recursion depth is limited
1509to 32766, or perhaps less in architectures where the stack cannot grow
1510arbitrarily. ("Simple" and "medium" situations are handled without
1511recursion and are not subject to a limit.) Try shortening the string
1512under examination; looping in Perl code (e.g. with C<while>) rather than
1513in the regular expression engine; or rewriting the regular expression so
c2e66d9e 1514that it is simpler or backtracks less. (See L<perlfaq2> for information
be771a83 1515on I<Mastering Regular Expressions>.)
c3464db5 1516
69282e91 1517=item connect() on closed socket %s
a0d0e21e 1518
be771a83
GS
1519(W closed) You tried to do a connect on a closed socket. Did you forget
1520to check the return value of your socket() call? See
1521L<perlfunc/connect>.
a0d0e21e 1522
e21e7c6a
FC
1523=item Constant(%s): Call to &{$^H{%s}} did not return a defined value
1524
1525(F) The subroutine registered to handle constant overloading
1526(see L<overload>) or a custom charnames handler (see
1527L<charnames/CUSTOM TRANSLATORS>) returned an undefined value.
1528
1529=item Constant(%s): $^H{%s} is not defined
1530
1531(F) The parser found inconsistencies while attempting to define an
1532overloaded constant. Perhaps you forgot to load the corresponding
f738a371 1533L<overload> pragma?
e21e7c6a 1534
779c5bc9
GS
1535=item Constant is not %s reference
1536
1537(F) A constant value (perhaps declared using the C<use constant> pragma)
be771a83 1538is being dereferenced, but it amounts to the wrong type of reference.
6903afa2 1539The message indicates the type of reference that was expected. This
be771a83 1540usually indicates a syntax error in dereferencing the constant value.
779c5bc9
GS
1541See L<perlsub/"Constant Functions"> and L<constant>.
1542
4cee8e80
CS
1543=item Constant subroutine %s redefined
1544
aeb94125
FC
1545(W redefine)(S) You redefined a subroutine which had previously
1546been eligible for inlining. See L<perlsub/"Constant Functions">
1547for commentary and workarounds.
4cee8e80 1548
9607fc9c
PP
1549=item Constant subroutine %s undefined
1550
be771a83
GS
1551(W misc) You undefined a subroutine which had previously been eligible
1552for inlining. See L<perlsub/"Constant Functions"> for commentary and
1553workarounds.
9607fc9c 1554
5a25739d
FC
1555=item Constant(%s) unknown
1556
1557(F) The parser found inconsistencies either while attempting
1558to define an overloaded constant, or when trying to find the
1559character name specified in the C<\N{...}> escape. Perhaps you
1560forgot to load the corresponding L<overload> pragma?.
1561
e7ea3e70
IZ
1562=item Copy method did not return a reference
1563
6903afa2 1564(F) The method which overloads "=" is buggy. See
13a2d996 1565L<overload/Copy Constructor>.
e7ea3e70 1566
4aaa4757
FC
1567=item &CORE::%s cannot be called directly
1568
1569(F) You tried to call a subroutine in the C<CORE::> namespace
8d605c0d 1570with C<&foo> syntax or through a reference. Some subroutines
4aaa4757
FC
1571in this package cannot yet be called that way, but must be
1572called as barewords. Something like this will work:
1573
1574 BEGIN { *shove = \&CORE::push; }
1575 shove @array, 1,2,3; # pushes on to @array
1576
6798c92b
GS
1577=item CORE::%s is not a keyword
1578
1579(F) The CORE:: namespace is reserved for Perl keywords.
1580
675fa9ff
FC
1581=item Corrupted regexp opcode %d > %d
1582
1583(P) This is either an error in Perl, or, if you're using
1584one, your L<custom regular expression engine|perlreapi>. If not the
1585latter, report the problem through the L<perlbug> utility.
1586
a0d0e21e
LW
1587=item corrupted regexp pointers
1588
1589(P) The regular expression engine got confused by what the regular
1590expression compiler gave it.
1591
1592=item corrupted regexp program
1593
be771a83
GS
1594(P) The regular expression engine got passed a regexp program without a
1595valid magic number.
a0d0e21e 1596
de42a5a9 1597=item Corrupt malloc ptr 0x%x at 0x%x
6df41af2
GS
1598
1599(P) The malloc package that comes with Perl had an internal failure.
1600
49704364
LW
1601=item Count after length/code in unpack
1602
1603(F) You had an unpack template indicating a counted-length string, but
1604you have also specified an explicit size for the string. See
1605L<perlfunc/pack>.
1606
f2cccb4c
KW
1607=for comment
1608The following are used in lib/diagnostics.t for testing two =items that
1609share the same description. Changes here need to be propagated to there
1610
6651ba0b
FC
1611=item Deep recursion on anonymous subroutine
1612
a0d0e21e
LW
1613=item Deep recursion on subroutine "%s"
1614
be771a83
GS
1615(W recursion) This subroutine has called itself (directly or indirectly)
1616100 times more than it has returned. This probably indicates an
1617infinite recursion, unless you're writing strange benchmark programs, in
1618which case it indicates something else.
a0d0e21e 1619
aad1d01f
NC
1620This threshold can be changed from 100, by recompiling the F<perl> binary,
1621setting the C pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value.
1622
e0e4a6e3
FC
1623=item (?(DEFINE)....) does not allow branches in regex; marked by
1624S<<-- HERE> in m/%s/
bcb95744 1625
6903afa2 1626(F) You used something like C<(?(DEFINE)...|..)> which is illegal. The
bcb95744
FC
1627most likely cause of this error is that you left out a parenthesis inside
1628of the C<....> part.
1629
9e3ec65c 1630The <-- HERE shows whereabouts in the regular expression the problem was
bcb95744
FC
1631discovered.
1632
62658f4d
PM
1633=item %s defines neither package nor VERSION--version check failed
1634
1635(F) You said something like "use Module 42" but in the Module file
1636there are neither package declarations nor a C<$VERSION>.
1637
36447869
FC
1638=item delete argument is index/value array slice, use array slice
1639
1640(F) You used index/value array slice syntax (C<%array[...]>) as
1641the argument to C<delete>. You probably meant C<@array[...]> with
1642an @ symbol instead.
1643
1644=item delete argument is key/value hash slice, use hash slice
1645
1646(F) You used key/value hash slice syntax (C<%hash{...}>) as the argument to
1647C<delete>. You probably meant C<@hash{...}> with an @ symbol instead.
1648
0ffcbc25
FC
1649=item delete argument is not a HASH or ARRAY element or slice
1650
4a0af295 1651(F) The argument to C<delete> must be either a hash or array element,
0ffcbc25
FC
1652such as:
1653
1654 $foo{$bar}
1655 $ref->{"susie"}[12]
1656
1657or a hash or array slice, such as:
1658
1659 @foo[$bar, $baz, $xyzzy]
1660 @{$ref->[12]}{"susie", "queue"}
1661
fc36a67e
PP
1662=item Delimiter for here document is too long
1663
be771a83
GS
1664(F) In a here document construct like C<<<FOO>, the label C<FOO> is too
1665long for Perl to handle. You have to be seriously twisted to write code
1666that triggers this error.
fc36a67e 1667
6d3b25aa
RGS
1668=item Deprecated use of my() in false conditional
1669
fa816bf3
FC
1670(D deprecated) You used a declaration similar to C<my $x if 0>. There
1671has been a long-standing bug in Perl that causes a lexical variable
6d3b25aa 1672not to be cleared at scope exit when its declaration includes a false
6903afa2 1673conditional. Some people have exploited this bug to achieve a kind of
fa816bf3 1674static variable. Since we intend to fix this bug, we don't want people
6903afa2 1675relying on this behavior. You can achieve a similar static effect by
6d3b25aa 1676declaring the variable in a separate block outside the function, eg
36fb85f3 1677
6d3b25aa
RGS
1678 sub f { my $x if 0; return $x++ }
1679
1680becomes
1681
1682 { my $x; sub f { return $x++ } }
1683
ea9d9ebc 1684Beginning with perl 5.10.0, you can also use C<state> variables to have
fa816bf3 1685lexicals that are initialized only once (see L<feature>):
36fb85f3
RGS
1686
1687 sub f { state $x; return $x++ }
1688
500ab966
RGS
1689=item DESTROY created new reference to dead object '%s'
1690
1691(F) A DESTROY() method created a new reference to the object which is
6903afa2
FC
1692just being DESTROYed. Perl is confused, and prefers to abort rather
1693than to create a dangling reference.
500ab966 1694
3cdd684c
TP
1695=item Did not produce a valid header
1696
1697See Server error.
1698
6df41af2
GS
1699=item %s did not return a true value
1700
1701(F) A required (or used) file must return a true value to indicate that
1702it compiled correctly and ran its initialization code correctly. It's
1703traditional to end such a file with a "1;", though any true value would
1704do. See L<perlfunc/require>.
1705
cc507455 1706=item (Did you mean &%s instead?)
4633a7c4 1707
413ff9f6
FC
1708(W misc) You probably referred to an imported subroutine &FOO as $FOO or
1709some such.
4633a7c4 1710
cc507455 1711=item (Did you mean "local" instead of "our"?)
33633739 1712
be771a83
GS
1713(W misc) Remember that "our" does not localize the declared global
1714variable. You have declared it again in the same lexical scope, which
1715seems superfluous.
33633739 1716
cc507455 1717=item (Did you mean $ or @ instead of %?)
a0d0e21e 1718
be771a83
GS
1719(W) You probably said %hash{$key} when you meant $hash{$key} or
1720@hash{@keys}. On the other hand, maybe you just meant %hash and got
1721carried away.
748a9306 1722
7e1af8bc 1723=item Died
5f05dabc
PP
1724
1725(F) You passed die() an empty string (the equivalent of C<die "">) or
075b00aa 1726you called it with no args and C<$@> was empty.
5f05dabc 1727
3cdd684c
TP
1728=item Document contains no data
1729
1730See Server error.
1731
62658f4d
PM
1732=item %s does not define %s::VERSION--version check failed
1733
1734(F) You said something like "use Module 42" but the Module did not
943fc58e 1735define a C<$VERSION>.
62658f4d 1736
49704364
LW
1737=item '/' does not take a repeat count
1738
1739(F) You cannot put a repeat count of any kind right after the '/' code.
1740See L<perlfunc/pack>.
1741
95cb0d72
FC
1742=item Don't know how to get file name
1743
1744(P) C<PerlIO_getname>, a perl internal I/O function specific to VMS, was
1745somehow called on another platform. This should not happen.
1746
4021c788 1747=item Don't know how to handle magic of type \%o
a0d0e21e
LW
1748
1749(P) The internal handling of magical variables has been cursed.
1750
1751=item do_study: out of memory
1752
1753(P) This should have been caught by safemalloc() instead.
1754
6df41af2
GS
1755=item (Do you need to predeclare %s?)
1756
56da5a46
RGS
1757(S syntax) This is an educated guess made in conjunction with the message
1758"%s found where operator expected". It often means a subroutine or module
6df41af2
GS
1759name is being referenced that hasn't been declared yet. This may be
1760because of ordering problems in your file, or because of a missing
be771a83
GS
1761"sub", "package", "require", or "use" statement. If you're referencing
1762something that isn't defined yet, you don't actually have to define the
1763subroutine or package before the current location. You can use an empty
1764"sub foo;" or "package FOO;" to enter a "forward" declaration.
6df41af2 1765
ac206dc8
RGS
1766=item dump() better written as CORE::dump()
1767
1768(W misc) You used the obsolescent C<dump()> built-in function, without fully
1769qualifying it as C<CORE::dump()>. Maybe it's a typo. See L<perlfunc/dump>.
1770
84d78eb7
YO
1771=item dump is not supported
1772
1773(F) Your machine doesn't support dump/undump.
1774
a0d0e21e
LW
1775=item Duplicate free() ignored
1776
be771a83
GS
1777(S malloc) An internal routine called free() on something that had
1778already been freed.
a0d0e21e 1779
1109a392
MHM
1780=item Duplicate modifier '%c' after '%c' in %s
1781
35f0cd76
FC
1782(W unpack) You have applied the same modifier more than once after a
1783type in a pack template. See L<perlfunc/pack>.
1109a392 1784
0953b66b
FC
1785=item each on reference is experimental
1786
0773cb3e
FC
1787(S experimental::autoderef) C<each> with a scalar argument is experimental
1788and may change or be removed in a future Perl version. If you want to
1789take the risk of using this feature, simply disable this warning:
0953b66b 1790
d401967c 1791 no warnings "experimental::autoderef";
0953b66b 1792
4633a7c4
LW
1793=item elseif should be elsif
1794
fa816bf3
FC
1795(S syntax) There is no keyword "elseif" in Perl because Larry thinks
1796it's ugly. Your code will be interpreted as an attempt to call a method
1797named "elseif" for the class returned by the following block. This is
4633a7c4
LW
1798unlikely to be what you want.
1799
e0e4a6e3 1800=item Empty \%c{} in regex; marked by S<<-- HERE> in m/%s/
ab13f0c7 1801
af6f566e 1802(F) C<\p> and C<\P> are used to introduce a named Unicode property, as
6903afa2 1803described in L<perlunicode> and L<perlre>. You used C<\p> or C<\P> in
af6f566e 1804a regular expression without specifying the property name.
ab13f0c7 1805
85ab1d1d 1806=item entering effective %s failed
5ff3f7a4 1807
85ab1d1d 1808(F) While under the C<use filetest> pragma, switching the real and
5ff3f7a4
GS
1809effective uids or gids failed.
1810
c038024b
RGS
1811=item %ENV is aliased to %s
1812
1813(F) You're running under taint mode, and the C<%ENV> variable has been
1814aliased to another hash, so it doesn't reflect anymore the state of the
6903afa2 1815program's environment. This is potentially insecure.
c038024b 1816
748a9306
LW
1817=item Error converting file specification %s
1818
5f05dabc 1819(F) An error peculiar to VMS. Because Perl may have to deal with file
748a9306 1820specifications in either VMS or Unix syntax, it converts them to a
be771a83
GS
1821single form when it must operate on them directly. Either you've passed
1822an invalid file specification to Perl, or you've found a case the
1823conversion routines don't handle. Drat.
748a9306 1824
ad19ef22 1825=item Eval-group in insecure regular expression
e4d48cc9 1826
be771a83
GS
1827(F) Perl detected tainted data when trying to compile a regular
1828expression that contains the C<(?{ ... })> zero-width assertion, which
1829is unsafe. See L<perlre/(?{ code })>, and L<perlsec>.
e4d48cc9 1830
ad19ef22 1831=item Eval-group not allowed at runtime, use re 'eval' in regex m/%s/
e4d48cc9 1832
be771a83
GS
1833(F) Perl tried to compile a regular expression containing the
1834C<(?{ ... })> zero-width assertion at run time, as it would when the
f11307f5
FC
1835pattern contains interpolated values. Since that is a security risk,
1836it is not allowed. If you insist, you may still do this by using the
1837C<re 'eval'> pragma or by explicitly building the pattern from an
1838interpolated string at run time and using that in an eval(). See
1839L<perlre/(?{ code })>.
e4d48cc9 1840
ad19ef22 1841=item Eval-group not allowed, use re 'eval' in regex m/%s/
6df41af2 1842
be771a83
GS
1843(F) A regular expression contained the C<(?{ ... })> zero-width
1844assertion, but that construct is only allowed when the C<use re 'eval'>
1845pragma is in effect. See L<perlre/(?{ code })>.
6df41af2 1846
e0e4a6e3
FC
1847=item EVAL without pos change exceeded limit in regex; marked by
1848S<<-- HERE> in m/%s/
1a147d38
YO
1849
1850(F) You used a pattern that nested too many EVAL calls without consuming
6903afa2 1851any text. Restructure the pattern so that text is consumed.
1a147d38 1852
9e3ec65c 1853The <-- HERE shows whereabouts in the regular expression the problem was
1a147d38
YO
1854discovered.
1855
fc36a67e
PP
1856=item Excessively long <> operator
1857
1858(F) The contents of a <> operator may not exceed the maximum size of a
1859Perl identifier. If you're just trying to glob a long list of
1860filenames, try using the glob() operator, or put the filenames into a
1861variable and glob that.
1862
ed9aa3b7
SG
1863=item exec? I'm not *that* kind of operating system
1864
af8bb25a 1865(F) The C<exec> function is not implemented on some systems, e.g., Symbian
6903afa2 1866OS. See L<perlport>.
ed9aa3b7 1867
fe13d51d 1868=item Execution of %s aborted due to compilation errors.
a0d0e21e
LW
1869
1870(F) The final summary message when a Perl compilation fails.
1871
0ffcbc25
FC
1872=item exists argument is not a HASH or ARRAY element or a subroutine
1873
4a0af295 1874(F) The argument to C<exists> must be a hash or array element or a
0ffcbc25
FC
1875subroutine with an ampersand, such as:
1876
1877 $foo{$bar}
1878 $ref->{"susie"}[12]
1879 &do_something
1880
1881=item exists argument is not a subroutine name
1882
ccfc2567
FC
1883(F) The argument to C<exists> for C<exists &sub> must be a subroutine name,
1884and not a subroutine call. C<exists &sub()> will generate this error.
0ffcbc25 1885
a0d0e21e
LW
1886=item Exiting eval via %s
1887
be771a83
GS
1888(W exiting) You are exiting an eval by unconventional means, such as a
1889goto, or a loop control statement.
e476b1b5
GS
1890
1891=item Exiting format via %s
1892
9a2ff54b 1893(W exiting) You are exiting a format by unconventional means, such as a
be771a83 1894goto, or a loop control statement.
a0d0e21e 1895
0a753a76
PP
1896=item Exiting pseudo-block via %s
1897
be771a83
GS
1898(W exiting) You are exiting a rather special block construct (like a
1899sort block or subroutine) by unconventional means, such as a goto, or a
1900loop control statement. See L<perlfunc/sort>.
0a753a76 1901
a0d0e21e
LW
1902=item Exiting subroutine via %s
1903
be771a83
GS
1904(W exiting) You are exiting a subroutine by unconventional means, such
1905as a goto, or a loop control statement.
a0d0e21e
LW
1906
1907=item Exiting substitution via %s
1908
be771a83
GS
1909(W exiting) You are exiting a substitution by unconventional means, such
1910as a return, a goto, or a loop control statement.
a0d0e21e 1911
e0e4a6e3 1912=item Expecting close bracket in regex; marked by S<<-- HERE> in m/%s/
c608e803 1913
675fa9ff 1914(F) You wrote something like
c608e803
KW
1915
1916 (?13
1917
1918to denote a capturing group of the form
1919L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>,
1920but omitted the C<")">.
1921
e0e4a6e3 1922=item Expecting '(?flags:(?[...' in regex; marked by S<<-- HERE> in m/%s/
27350048 1923
8b6fbf55
FC
1924(F) The C<(?[...])> extended character class regular expression construct
1925only allows character classes (including character class escapes like
1926C<\d>), operators, and parentheses. The one exception is C<(?flags:...)>
1927containing at least one flag and exactly one C<(?[...])> construct.
27350048
FC
1928This allows a regular expression containing just C<(?[...])> to be
1929interpolated. If you see this error message, then you probably
1930have some other C<(?...)> construct inside your character class. See
1931L<perlrecharclass/Extended Bracketed Character Classes>.
1932
30d9c59b
Z
1933=item Experimental subroutine signatures not enabled
1934
1935(F) To use subroutine signatures, you must first enable them:
1936
caa35032 1937 no warnings "experimental::signatures";
30d9c59b
Z
1938 use feature "signatures";
1939 sub foo ($left, $right) { ... }
1940
6da34ecb
FC
1941=item Experimental "%s" subs not enabled
1942
1943(F) To use lexical subs, you must first enable them:
1944
1945 no warnings 'experimental::lexical_subs';
1946 use feature 'lexical_subs';
1947 my sub foo { ... }
1948
7b8d334a
GS
1949=item Explicit blessing to '' (assuming package main)
1950
be771a83
GS
1951(W misc) You are blessing a reference to a zero length string. This has
1952the effect of blessing the reference into the package main. This is
1953usually not what you want. Consider providing a default target package,
1954e.g. bless($ref, $p || 'MyPackage');
7b8d334a 1955
6df41af2
GS
1956=item %s: Expression syntax
1957
be771a83
GS
1958(A) You've accidentally run your script through B<csh> instead of Perl.
1959Check the #! line, or manually feed your script into Perl yourself.
6df41af2
GS
1960
1961=item %s failed--call queue aborted
1962
3c10abe3
AG
1963(F) An untrapped exception was raised while executing a UNITCHECK,
1964CHECK, INIT, or END subroutine. Processing of the remainder of the
1965queue of such routines has been prematurely ended.
6df41af2 1966
e0e4a6e3 1967=item False [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
73b437c8 1968
98d31c73 1969(W regexp)(F) A character class range must start and end at a literal
7253e4e3 1970character, not another character class like C<\d> or C<[:alpha:]>. The "-"
3c6ca74a
FC
1971in your false range is interpreted as a literal "-". In a C<(?[...])>
1972construct, this is an error, rather than a warning. Consider quoting
e0e4a6e3 1973the "-", "\-". The S<<-- HERE> shows whereabouts in the regular expression
3c6ca74a 1974the problem was discovered. See L<perlre>.
73b437c8 1975
1b1ee2ef 1976=item Fatal VMS error (status=%d) at %s, line %d
a0d0e21e 1977
be771a83
GS
1978(P) An error peculiar to VMS. Something untoward happened in a VMS
1979system service or RTL routine; Perl's exit status should provide more
1980details. The filename in "at %s" and the line number in "line %d" tell
1981you which section of the Perl source code is distressed.
a0d0e21e
LW
1982
1983=item fcntl is not implemented
1984
1985(F) Your machine apparently doesn't implement fcntl(). What is this, a
1986PDP-11 or something?
1987
22846ab4
AB
1988=item FETCHSIZE returned a negative value
1989
1990(F) A tied array claimed to have a negative number of elements, which
1991is not possible.
1992
f337b084
TH
1993=item Field too wide in 'u' format in pack
1994
d8b5cc61 1995(W pack) Each line in an uuencoded string starts with a length indicator
6903afa2
FC
1996which can't encode values above 63. So there is no point in asking for
1997a line length bigger than that. Perl will behave as if you specified
5c96f6f7 1998C<u63> as the format.
f337b084 1999
af8c498a 2000=item Filehandle %s opened only for input
a0d0e21e 2001
6c8d78fb
HS
2002(W io) You tried to write on a read-only filehandle. If you intended
2003it to be a read-write filehandle, you needed to open it with "+<" or
2004"+>" or "+>>" instead of with "<" or nothing. If you intended only to
2005write the file, use ">" or ">>". See L<perlfunc/open>.
a0d0e21e 2006
af8c498a 2007=item Filehandle %s opened only for output
a0d0e21e 2008
6c8d78fb
HS
2009(W io) You tried to read from a filehandle opened only for writing, If
2010you intended it to be a read/write filehandle, you needed to open it
89a1bda8
FC
2011with "+<" or "+>" or "+>>" instead of with ">". If you intended only to
2012read from the file, use "<". See L<perlfunc/open>. Another possibility
2013is that you attempted to open filedescriptor 0 (also known as STDIN) for
2014output (maybe you closed STDIN earlier?).
97828cef
RGS
2015
2016=item Filehandle %s reopened as %s only for input
2017
2018(W io) You opened for reading a filehandle that got the same filehandle id
6903afa2 2019as STDOUT or STDERR. This occurred because you closed STDOUT or STDERR
97828cef
RGS
2020previously.
2021
2022=item Filehandle STDIN reopened as %s only for output
2023
2024(W io) You opened for writing a filehandle that got the same filehandle id
fa816bf3 2025as STDIN. This occurred because you closed STDIN previously.
a0d0e21e
LW
2026
2027=item Final $ should be \$ or $name
2028
2029(F) You must now decide whether the final $ in a string was meant to be
be771a83
GS
2030a literal dollar sign, or was meant to introduce a variable name that
2031happens to be missing. So you have to put either the backslash or the
2032name.
a0d0e21e 2033
56e90b21
GS
2034=item flock() on closed filehandle %s
2035
be771a83 2036(W closed) The filehandle you're attempting to flock() got itself closed
c289d2f7 2037some time before now. Check your control flow. flock() operates on
be771a83
GS
2038filehandles. Are you attempting to call flock() on a dirhandle by the
2039same name?
56e90b21 2040
6df41af2
GS
2041=item Format not terminated
2042
2043(F) A format must be terminated by a line with a solitary dot. Perl got
2044to the end of your file without finding such a line.
2045
a0d0e21e
LW
2046=item Format %s redefined
2047
e476b1b5 2048(W redefine) You redefined a format. To suppress this warning, say
a0d0e21e
LW
2049
2050 {
271595cc 2051 no warnings 'redefine';
a0d0e21e
LW
2052 eval "format NAME =...";
2053 }
2054
a0d0e21e
LW
2055=item Found = in conditional, should be ==
2056
e476b1b5 2057(W syntax) You said
a0d0e21e
LW
2058
2059 if ($foo = 123)
2060
2061when you meant
2062
2063 if ($foo == 123)
2064
2065(or something like that).
2066
6df41af2
GS
2067=item %s found where operator expected
2068
56da5a46
RGS
2069(S syntax) The Perl lexer knows whether to expect a term or an operator.
2070If it sees what it knows to be a term when it was expecting to see an
be771a83
GS
2071operator, it gives you this warning. Usually it indicates that an
2072operator or delimiter was omitted, such as a semicolon.
6df41af2 2073
a0d0e21e
LW
2074=item gdbm store returned %d, errno %d, key "%s"
2075
2076(S) A warning from the GDBM_File extension that a store failed.
2077
2078=item gethostent not implemented
2079
2080(F) Your C library apparently doesn't implement gethostent(), probably
2081because if it did, it'd feel morally obligated to return every hostname
2082on the Internet.
2083
69282e91 2084=item get%sname() on closed socket %s
a0d0e21e 2085
be771a83
GS
2086(W closed) You tried to get a socket or peer socket name on a closed
2087socket. Did you forget to check the return value of your socket() call?
a0d0e21e 2088
748a9306
LW
2089=item getpwnam returned invalid UIC %#o for user "%s"
2090
2091(S) A warning peculiar to VMS. The call to C<sys$getuai> underlying the
2092C<getpwnam> operator returned an invalid UIC.
2093
6df41af2
GS
2094=item getsockopt() on closed socket %s
2095
be771a83
GS
2096(W closed) You tried to get a socket option on a closed socket. Did you
2097forget to check the return value of your socket() call? See
6df41af2
GS
2098L<perlfunc/getsockopt>.
2099
0f539b13
BF
2100=item given is experimental
2101
675fa9ff
FC
2102(S experimental::smartmatch) C<given> depends on smartmatch, which
2103is experimental, so its behavior may change or even be removed
2104in any future release of perl. See the explanation under
2105L<perlsyn/Experimental Details on given and when>.
0f539b13 2106
6df41af2
GS
2107=item Global symbol "%s" requires explicit package name
2108
a4edf47d 2109(F) You've said "use strict" or "use strict vars", which indicates
30c282f6 2110that all variables must either be lexically scoped (using "my" or "state"),
a4edf47d
GS
2111declared beforehand using "our", or explicitly qualified to say
2112which package the global variable is in (using "::").
6df41af2 2113
e476b1b5
GS
2114=item glob failed (%s)
2115
5ead438e 2116(S glob) Something went wrong with the external program(s) used
73c4e9dc
FC
2117for C<glob> and C<< <*.c> >>. Usually, this means that you supplied a C<glob>
2118pattern that caused the external program to fail and exit with a
be771a83 2119nonzero status. If the message indicates that the abnormal exit
73c4e9dc
FC
2120resulted in a coredump, this may also mean that your csh (C shell)
2121is broken. If so, you should change all of the csh-related variables
2122in config.sh: If you have tcsh, make the variables refer to it as
2123if it were csh (e.g. C<full_csh='/usr/bin/tcsh'>); otherwise, make them
2124all empty (except that C<d_csh> should be C<'undef'>) so that Perl will
be771a83 2125think csh is missing. In either case, after editing config.sh, run
75b44862 2126C<./Configure -S> and rebuild Perl.
e476b1b5 2127
a0d0e21e
LW
2128=item Glob not terminated
2129
2130(F) The lexer saw a left angle bracket in a place where it was expecting
be771a83
GS
2131a term, so it's looking for the corresponding right angle bracket, and
2132not finding it. Chances are you left some needed parentheses out
2133earlier in the line, and you really meant a "less than".
a0d0e21e 2134
b35b96b6
JH
2135=item gmtime(%f) failed
2136
2137(W overflow) You called C<gmtime> with a number that it could not handle:
2138too large, too small, or NaN. The returned value is C<undef>.
2139
bcd05b94 2140=item gmtime(%f) too large
8b56d6ff 2141
e9200be3 2142(W overflow) You called C<gmtime> with a number that was larger than
fc003d4b 2143it can reliably handle and C<gmtime> probably returned the wrong
6903afa2 2144date. This warning is also triggered with NaN (the special
fc003d4b
MS
2145not-a-number value).
2146
bcd05b94 2147=item gmtime(%f) too small
fc003d4b 2148
e9200be3 2149(W overflow) You called C<gmtime> with a number that was smaller than
e7a1a147 2150it can reliably handle and C<gmtime> probably returned the wrong date.
8b56d6ff 2151
6df41af2 2152=item Got an error from DosAllocMem
a0d0e21e 2153
6df41af2
GS
2154(P) An error peculiar to OS/2. Most probably you're using an obsolete
2155version of Perl, and this should not happen anyway.
a0d0e21e
LW
2156
2157=item goto must have label
2158
2159(F) Unlike with "next" or "last", you're not allowed to goto an
2160unspecified destination. See L<perlfunc/goto>.
2161
6651ba0b
FC
2162=item Goto undefined subroutine%s
2163
2164(F) You tried to call a subroutine with C<goto &sub> syntax, but
2165the indicated subroutine hasn't been defined, or if it was, it
2166has since been undefined.
2167
6fbc9859 2168=item Group name must start with a non-digit word character in regex; marked by
e0e4a6e3 2169S<<-- HERE> in m/%s/
1f4f6bf1
YO
2170
2171(F) Group names must follow the rules for perl identifiers, meaning
f26c79ba
FC
2172they must start with a non-digit word character. A common cause of
2173this error is using (?&0) instead of (?0). See L<perlre>.
1f4f6bf1 2174
5a25739d
FC
2175=item ()-group starts with a count
2176
2177(F) A ()-group started with a count. A count is supposed to follow
2178something: a template character or a ()-group. See L<perlfunc/pack>.
2179
fe13d51d 2180=item %s had compilation errors.
6df41af2
GS
2181
2182(F) The final summary message when a C<perl -c> fails.
2183
a0d0e21e
LW
2184=item Had to create %s unexpectedly
2185
be771a83
GS
2186(S internal) A routine asked for a symbol from a symbol table that ought
2187to have existed already, but for some reason it didn't, and had to be
2188created on an emergency basis to prevent a core dump.
a0d0e21e 2189
6df41af2
GS
2190=item %s has too many errors
2191
2192(F) The parser has given up trying to parse the program after 10 errors.
2193Further error messages would likely be uninformative.
2194
61e61fbc
JH
2195=item Hexadecimal float: exponent overflow
2196
d8f2b442 2197(W overflow) The hexadecimal floating point has a larger exponent
61e61fbc
JH
2198than the floating point supports.
2199
2200=item Hexadecimal float: exponent underflow
2201
d8f2b442 2202(W overflow) The hexadecimal floating point has a smaller exponent
61e61fbc
JH
2203than the floating point supports.
2204
cf4f6003
JH
2205=item Hexadecimal float: internal error
2206
2207(F) Something went horribly bad in hexadecimal float handling.
2208
61e61fbc
JH
2209=item Hexadecimal float: mantissa overflow
2210
2211(W overflow) The hexadecimal floating point literal had more bits in
2212the mantissa (the part between the 0x and the exponent, also known as
2213the fraction or the significand) than the floating point supports.
2214
40bca5ae
JH
2215=item Hexadecimal float: precision loss
2216
2217(W overflow) The hexadecimal floating point had internally more
2218digits than could be output. This can be caused by unsupported
2219long double formats, or by 64-bit integers not being available
2220(needed to retrieve the digits under some configurations).
2221
2222=item Hexadecimal float: unsupported long double format
2223
2224(F) You have configured Perl to use long doubles but
d8f2b442 2225the internals of the long double format are unknown;
40bca5ae
JH
2226therefore the hexadecimal float output is impossible.
2227
252aa082
JH
2228=item Hexadecimal number > 0xffffffff non-portable
2229
e476b1b5 2230(W portable) The hexadecimal number you specified is larger than 2**32-1
9e24b6e2
JH
2231(4294967295) and therefore non-portable between systems. See
2232L<perlport> for more on portability concerns.
252aa082 2233
8903cb82
PP
2234=item Identifier too long
2235
2236(F) Perl limits identifiers (names for variables, functions, etc.) to
fc36a67e 2237about 250 characters for simple names, and somewhat more for compound
be771a83
GS
2238names (like C<$A::B>). You've exceeded Perl's limits. Future versions
2239of Perl are likely to eliminate these arbitrary limitations.
8903cb82 2240
e0e4a6e3
FC
2241=item Ignoring zero length \N{} in character class in regex; marked by
2242S<<-- HERE> in m/%s/
fc8cd66c 2243
b5e3739b
FC
2244(W regexp) Named Unicode character escapes C<(\N{...})> may return a
2245zero-length sequence. When such an escape is used in a character class
2246its behaviour is not well defined. Check that the correct escape has
fc8cd66c
YO
2247been used, and the correct charname handler is in scope.
2248
6df41af2 2249=item Illegal binary digit %s
f675dbe5 2250
6df41af2 2251(F) You used a digit other than 0 or 1 in a binary number.
f675dbe5 2252
6df41af2 2253=item Illegal binary digit %s ignored
a0d0e21e 2254
be771a83
GS
2255(W digit) You may have tried to use a digit other than 0 or 1 in a
2256binary number. Interpretation of the binary number stopped before the
2257offending digit.
a0d0e21e 2258
6597eb22
FC
2259=item Illegal character after '_' in prototype for %s : %s
2260
e4d150f1
FC
2261(W illegalproto) An illegal character was found in a prototype
2262declaration. The '_' in a prototype must be followed by a ';',
2263indicating the rest of the parameters are optional, or one of '@'
2264or '%', since those two will accept 0 or more final parameters.
6597eb22 2265
78d0fecf 2266=item Illegal character \%o (carriage return)
4fdae800 2267
d5898338 2268(F) Perl normally treats carriage returns in the program text as it
be771a83
GS
2269would any other whitespace, which means you should never see this error
2270when Perl was built using standard options. For some reason, your
2271version of Perl appears to have been built without this support. Talk
2272to your Perl administrator.
4fdae800 2273
d37a9538
ST
2274=item Illegal character in prototype for %s : %s
2275
197afce1 2276(W illegalproto) An illegal character was found in a prototype declaration.
2e9cc7ef 2277Legal characters in prototypes are $, @, %, *, ;, [, ], &, \, and +.
30d9c59b
Z
2278Perhaps you were trying to write a subroutine signature but didn't enable
2279that feature first (C<use feature 'signatures'>), so your signature was
2280instead interpreted as a bad prototype.
d37a9538 2281
904d85c5
RGS
2282=item Illegal declaration of anonymous subroutine
2283
2284(F) When using the C<sub> keyword to construct an anonymous subroutine,
6903afa2 2285you must always specify a block of code. See L<perlsub>.
904d85c5 2286
8e742a20
MHM
2287=item Illegal declaration of subroutine %s
2288
6903afa2 2289(F) A subroutine was not declared correctly. See L<perlsub>.
8e742a20 2290
a0d0e21e
LW
2291=item Illegal division by zero
2292
be771a83
GS
2293(F) You tried to divide a number by 0. Either something was wrong in
2294your logic, or you need to put a conditional in to guard against
2295meaningless input.
a0d0e21e 2296
6df41af2
GS
2297=item Illegal hexadecimal digit %s ignored
2298
be771a83
GS
2299(W digit) You may have tried to use a character other than 0 - 9 or
2300A - F, a - f in a hexadecimal number. Interpretation of the hexadecimal
2301number stopped before the illegal character.
6df41af2 2302
a0d0e21e
LW
2303=item Illegal modulus zero
2304
be771a83
GS
2305(F) You tried to divide a number by 0 to get the remainder. Most
2306numbers don't take to this kindly.
a0d0e21e 2307
6df41af2 2308=item Illegal number of bits in vec
399388f4 2309
6df41af2
GS
2310(F) The number of bits in vec() (the third argument) must be a power of
2311two from 1 to 32 (or 64, if your platform supports that).
399388f4
GS
2312
2313=item Illegal octal digit %s
a0d0e21e 2314
d1be9408 2315(F) You used an 8 or 9 in an octal number.
a0d0e21e 2316
399388f4 2317=item Illegal octal digit %s ignored
748a9306 2318
d1be9408 2319(W digit) You may have tried to use an 8 or 9 in an octal number.
75b44862 2320Interpretation of the octal number stopped before the 8 or 9.
748a9306 2321
e0e4a6e3 2322=item Illegal pattern in regex; marked by S<<-- HERE> in m/%s/
c608e803 2323
675fa9ff 2324(F) You wrote something like
c608e803
KW
2325
2326 (?+foo)
2327
2328The C<"+"> is valid only when followed by digits, indicating a
2329capturing group. See
2330L<C<(?I<PARNO>)>|perlre/(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)>.
2331
375ed12a
JH
2332=item Illegal suidscript
2333
2334(F) The script run under suidperl was somehow illegal.
2335
fe13d51d 2336=item Illegal switch in PERL5OPT: -%c
6ff81951 2337
6df41af2 2338(X) The PERL5OPT environment variable may only be used to set the
646ca9b2 2339following switches: B<-[CDIMUdmtw]>.
6ff81951 2340
6df41af2 2341=item Ill-formed CRTL environ value "%s"
81e118e0 2342
75b44862 2343(W internal) A warning peculiar to VMS. Perl tried to read the CRTL's
be771a83
GS
2344internal environ array, and encountered an element without the C<=>
2345delimiter used to separate keys from values. The element is ignored.
09bef843 2346
6df41af2 2347=item Ill-formed message in prime_env_iter: |%s|
54310121 2348
be771a83
GS
2349(W internal) A warning peculiar to VMS. Perl tried to read a logical
2350name or CLI symbol definition when preparing to iterate over %ENV, and
2351didn't see the expected delimiter between key and value, so the line was
2352ignored.
54310121 2353
6df41af2 2354=item (in cleanup) %s
9607fc9c 2355
be771a83
GS
2356(W misc) This prefix usually indicates that a DESTROY() method raised
2357the indicated exception. Since destructors are usually called by the
2358system at arbitrary points during execution, and often a vast number of
2359times, the warning is issued only once for any number of failures that
2360would otherwise result in the same message being repeated.
6df41af2 2361
be771a83
GS
2362Failure of user callbacks dispatched using the C<G_KEEPERR> flag could
2363also result in this warning. See L<perlcall/G_KEEPERR>.
9607fc9c 2364
e0e4a6e3
FC
2365=item Incomplete expression within '(?[ ])' in regex; marked by S<<-- HERE>
2366in m/%s/
0d0b4b3b 2367
675fa9ff 2368(F) There was a syntax error within the C<(?[ ])>. This can happen if the
0d0b4b3b
KW
2369expression inside the construct was completely empty, or if there are
2370too many or few operands for the number of operators. Perl is not smart
2371enough to give you a more precise indication as to what is wrong.
2372
6fbc9859
MH
2373=item Inconsistent hierarchy during C3 merge of class '%s': merging failed on
2374parent '%s'
2c7d6b9c
RGS
2375
2376(F) The method resolution order (MRO) of the given class is not
2377C3-consistent, and you have enabled the C3 MRO for this class. See the C3
2378documentation in L<mro> for more information.
2379
979699d9
JH
2380=item In EBCDIC the v-string components cannot exceed 2147483647
2381
2382(F) An error peculiar to EBCDIC. Internally, v-strings are stored as
2383Unicode code points, and encoded in EBCDIC as UTF-EBCDIC. The UTF-EBCDIC
2384encoding is limited to code points no larger than 2147483647 (0x7FFFFFFF).
2385
6a2ed79a 2386=item Infinite recursion in regex
1a147d38
YO
2387
2388(F) You used a pattern that references itself without consuming any input
6903afa2 2389text. You should check the pattern to ensure that recursive patterns
1a147d38
YO
2390either consume text or fail.
2391
6dbe9451
NC
2392=item Initialization of state variables in list context currently forbidden
2393
6903afa2
FC
2394(F) Currently the implementation of "state" only permits the
2395initialization of scalar variables in scalar context. Re-write
2396C<state ($a) = 42> as C<state $a = 42> to change from list to scalar
2397context. Constructions such as C<state (@a) = foo()> will be
2398supported in a future perl release.
6dbe9451 2399
2186f873
FC
2400=item %%s[%s] in scalar context better written as $%s[%s]
2401
2402(W syntax) In scalar context, you've used an array index/value slice
2403(indicated by %) to select a single element of an array. Generally
2404it's better to ask for a scalar value (indicated by $). The difference
2405is that C<$foo[&bar]> always behaves like a scalar, both in the value it
2406returns and when evaluating its argument, while C<%foo[&bar]> provides
2407a list context to its subscript, which can do weird things if you're
2408expecting only one subscript. When called in list context, it also
2409returns the index (what C<&bar> returns) in addition to the value.
2410
2411=item %%s{%s} in scalar context better written as $%s{%s}
2412
2413(W syntax) In scalar context, you've used a hash key/value slice
2414(indicated by %) to select a single element of a hash. Generally it's
2415better to ask for a scalar value (indicated by $). The difference
2416is that C<$foo{&bar}> always behaves like a scalar, both in the value
2417it returns and when evaluating its argument, while C<@foo{&bar}> and
2418provides a list context to its subscript, which can do weird things
2419if you're expecting only one subscript. When called in list context,
2420it also returns the key in addition to the value.
2421
a0d0e21e
LW
2422=item Insecure dependency in %s
2423
8b1a09fc 2424(F) You tried to do something that the tainting mechanism didn't like.
be771a83
GS
2425The tainting mechanism is turned on when you're running setuid or
2426setgid, or when you specify B<-T> to turn it on explicitly. The
2427tainting mechanism labels all data that's derived directly or indirectly
2428from the user, who is considered to be unworthy of your trust. If any
2429such data is used in a "dangerous" operation, you get this error. See
2430L<perlsec> for more information.
a0d0e21e
LW
2431
2432=item Insecure directory in %s
2433
be771a83
GS
2434(F) You can't use system(), exec(), or a piped open in a setuid or
2435setgid script if C<$ENV{PATH}> contains a directory that is writable by
df98f984
RGS
2436the world. Also, the PATH must not contain any relative directory.
2437See L<perlsec>.
a0d0e21e 2438
62f468fc 2439=item Insecure $ENV{%s} while running %s
a0d0e21e
LW
2440
2441(F) You can't use system(), exec(), or a piped open in a setuid or
62f468fc 2442setgid script if any of C<$ENV{PATH}>, C<$ENV{IFS}>, C<$ENV{CDPATH}>,
332d5f78
SR
2443C<$ENV{ENV}>, C<$ENV{BASH_ENV}> or C<$ENV{TERM}> are derived from data
2444supplied (or potentially supplied) by the user. The script must set
2445the path to a known value, using trustworthy data. See L<perlsec>.
a0d0e21e 2446
0e9be77f
DM
2447=item Insecure user-defined property %s
2448
2449(F) Perl detected tainted data when trying to compile a regular
2450expression that contains a call to a user-defined character property
2451function, i.e. C<\p{IsFoo}> or C<\p{InFoo}>.
2452See L<perlunicode/User-Defined Character Properties> and L<perlsec>.
2453
b9ef414d
FC
2454=item Integer overflow in format string for %s
2455
2456(F) The indexes and widths specified in the format string of C<printf()>
2457or C<sprintf()> are too large. The numbers must not overflow the size of
2458integers for your architecture.
2459
a7ae9550
GS
2460=item Integer overflow in %s number
2461
35928bc5 2462(S overflow) The hexadecimal, octal or binary number you have specified
be771a83
GS
2463either as a literal or as an argument to hex() or oct() is too big for
2464your architecture, and has been converted to a floating point number.
2465On a 32-bit architecture the largest hexadecimal, octal or binary number
9e24b6e2
JH
2466representable without overflow is 0xFFFFFFFF, 037777777777, or
24670b11111111111111111111111111111111 respectively. Note that Perl
2468transparently promotes all numbers to a floating point representation
2469internally--subject to loss of precision errors in subsequent
2470operations.
bbce6d69 2471
fc89ca81
FC
2472=item Integer overflow in srand
2473
2474(S overflow) The number you have passed to srand is too big to fit
2475in your architecture's integer representation. The number has been
2476replaced with the largest integer supported (0xFFFFFFFF on 32-bit
2477architectures). This means you may be getting less randomness than
2478you expect, because different random seeds above the maximum will
2479return the same sequence of random numbers.
2480
46314c13
JP
2481=item Integer overflow in version
2482
18da5252
FC
2483=item Integer overflow in version %d
2484
784d71ed
FC
2485(W overflow) Some portion of a version initialization is too large for
2486the size of integers for your architecture. This is not a warning
f084e84f 2487because there is no rational reason for a version to try and use an
784d71ed
FC
2488element larger than typically 2**32. This is usually caused by trying
2489to use some odd mathematical operation as a version, like 100/9.
46314c13 2490
e0e4a6e3 2491=item Internal disaster in regex; marked by S<<-- HERE> in m/%s/
6df41af2
GS
2492
2493(P) Something went badly wrong in the regular expression parser.
e0e4a6e3 2494The S<<-- HERE> shows whereabouts in the regular expression the problem was
b45f050a
JF
2495discovered.
2496
748a9306
LW
2497=item Internal inconsistency in tracking vforks
2498
be771a83
GS
2499(S) A warning peculiar to VMS. Perl keeps track of the number of times
2500you've called C<fork> and C<exec>, to determine whether the current call
2501to C<exec> should affect the current script or a subprocess (see
2502L<perlvms/"exec LIST">). Somehow, this count has become scrambled, so
2503Perl is making a guess and treating this C<exec> as a request to
2504terminate the Perl script and execute the specified command.
748a9306 2505
870978ae
FC
2506=item internal %<num>p might conflict with future printf extensions
2507
2508(S internal) Perl's internal routine that handles C<printf> and C<sprintf>
2509formatting follows a slightly different set of rules when called from
2510C or XS code. Specifically, formats consisting of digits followed
2511by "p" (e.g., "%7p") are reserved for future use. If you see this
2512message, then an XS module tried to call that routine with one such
2513reserved format.
2514
e0e4a6e3 2515=item Internal urp in regex; marked by S<<-- HERE> in m/%s/
b45f050a 2516
fa816bf3 2517(P) Something went badly awry in the regular expression parser. The
e0e4a6e3 2518S<<-- HERE> shows whereabouts in the regular expression the problem was
7253e4e3 2519discovered.
a0d0e21e 2520
6df41af2
GS
2521=item %s (...) interpreted as function
2522
75b44862 2523(W syntax) You've run afoul of the rule that says that any list operator
be771a83 2524followed by parentheses turns into a function, with all the list
64977eb6 2525operators arguments found inside the parentheses. See
13a2d996 2526L<perlop/Terms and List Operators (Leftward)>.
6df41af2 2527
f51551f7
FC
2528=item In '(?...)', the '(' and '?' must be adjacent in regex;
2529marked by S<<-- HERE> in m/%s/
2530
2531(F) The two-character sequence C<"(?"> in this context in a regular
2532expression pattern should be an indivisible token, with nothing
2533intervening between the C<"("> and the C<"?">, but you separated them
2534with whitespace.
2535
09bef843
SB
2536=item Invalid %s attribute: %s
2537
a4a4c9e2 2538(F) The indicated attribute for a subroutine or variable was not recognized
09bef843
SB
2539by Perl or by a user-supplied handler. See L<attributes>.
2540
2541=item Invalid %s attributes: %s
2542
a4a4c9e2 2543(F) The indicated attributes for a subroutine or variable were not
be771a83 2544recognized by Perl or by a user-supplied handler. See L<attributes>.
09bef843 2545
e0e4a6e3
FC
2546=item Invalid character in charnames alias definition; marked by
2547S<<-- HERE> in '%s
225fb84f
KW
2548
2549(F) You tried to create a custom alias for a character name, with
2550the C<:alias> option to C<use charnames> and the specified character in
2551the indicated name isn't valid. See L<charnames/CUSTOM ALIASES>.
2552
c8028aa6
TC
2553=item Invalid \0 character in %s for %s: %s\0%s
2554
fa3234e3
FC
2555(W syscalls) Embedded \0 characters in pathnames or other system call
2556arguments produce a warning as of 5.20. The parts after the \0 were
2557formerly ignored by system calls.
c8028aa6 2558
e0e4a6e3 2559=item Invalid character in \N{...}; marked by S<<-- HERE> in \N{%s}
a690c7c4
FC
2560
2561(F) Only certain characters are valid for character names. The
2562indicated one isn't. See L<charnames/CUSTOM ALIASES>.
2563
c635e13b
PP
2564=item Invalid conversion in %s: "%s"
2565
be771a83
GS
2566(W printf) Perl does not understand the given format conversion. See
2567L<perlfunc/sprintf>.
c635e13b 2568
e0e4a6e3
FC
2569=item Invalid escape in the specified encoding in regex; marked by
2570S<<-- HERE> in m/%s/
9e08bc66 2571
98d31c73 2572(W regexp)(F) The numeric escape (for example C<\xHH>) of value < 256
9e08bc66
ST
2573didn't correspond to a single character through the conversion
2574from the encoding specified by the encoding pragma.
98d31c73
FC
2575The escape was replaced with REPLACEMENT CHARACTER (U+FFFD)
2576instead, except within S<C<(?[ ])>>, where it is a fatal error.
e0e4a6e3 2577The S<<-- HERE> shows whereabouts in the regular expression the
9e08bc66
ST
2578escape was discovered.
2579
8149aa9f
FC
2580=item Invalid hexadecimal number in \N{U+...}
2581
e0e4a6e3
FC
2582=item Invalid hexadecimal number in \N{U+...} in regex; marked by
2583S<<-- HERE> in m/%s/
aec0ef10 2584
8149aa9f 2585(F) The character constant represented by C<...> is not a valid hexadecimal
74f8e9e3
FC
2586number. Either it is empty, or you tried to use a character other than
25870 - 9 or A - F, a - f in a hexadecimal number.
8149aa9f 2588
6651ba0b
FC
2589=item Invalid module name %s with -%c option: contains single ':'
2590
2591(F) The module argument to perl's B<-m> and B<-M> command-line options
2592cannot contain single colons in the module name, but only in the
2593arguments after "=". In other words, B<-MFoo::Bar=:baz> is ok, but
2594B<-MFoo:Bar=baz> is not.
2595
2c7d6b9c
RGS
2596=item Invalid mro name: '%s'
2597
162a3e34
FC
2598(F) You tried to C<mro::set_mro("classname", "foo")> or C<use mro 'foo'>,
2599where C<foo> is not a valid method resolution order (MRO). Currently,
2600the only valid ones supported are C<dfs> and C<c3>, unless you have loaded
2601a module that is a MRO plugin. See L<mro> and L<perlmroapi>.
2c7d6b9c 2602
40e4140b
FC
2603=item Invalid negative number (%s) in chr
2604
2605(W utf8) You passed a negative number to C<chr>. Negative numbers are
1cd88304 2606not valid character numbers, so it return the Unicode replacement
40e4140b
FC
2607character (U+FFFD).
2608
1cd88304
JH
2609=item Invalid number (%f) in chr
2610
2611(W utf8) You passed an invalid number (like an infinity or
2612not-a-number) to C<chr>. Those are not valid character numbers,
2613so it return the Unicode replacement character (U+FFFD).
2614
6651ba0b
FC
2615=item invalid option -D%c, use -D'' to see choices
2616
8ff21bfe
FC
2617(S debugging) Perl was called with invalid debugger flags. Call perl
2618with the B<-D> option with no flags to see the list of acceptable values.
982c4ecb 2619See also L<perlrun/-Dletters>.
6651ba0b 2620
e0e4a6e3 2621=item Invalid [] range "%s" in regex; marked by S<<-- HERE> in m/%s/
6df41af2
GS
2622
2623(F) The range specified in a character class had a minimum character
7253e4e3
RK
2624greater than the maximum character. One possibility is that you forgot the
2625C<{}> from your ending C<\x{}> - C<\x> without the curly braces can go only
e0e4a6e3 2626up to C<ff>. The S<<-- HERE> shows whereabouts in the regular expression the
7253e4e3 2627problem was discovered. See L<perlre>.
6df41af2 2628
d1573ac7 2629=item Invalid range "%s" in transliteration operator
c2e66d9e
GS
2630
2631(F) The range specified in the tr/// or y/// operator had a minimum
2632character greater than the maximum character. See L<perlop>.
2633
09bef843
SB
2634=item Invalid separator character %s in attribute list
2635
0120eecf 2636(F) Something other than a colon or whitespace was seen between the
be771a83
GS
2637elements of an attribute list. If the previous attribute had a
2638parenthesised parameter list, perhaps that list was terminated too soon.
2639See L<attributes>.
09bef843 2640
b4581f09
JH
2641=item Invalid separator character %s in PerlIO layer specification %s
2642
2bfc5f71
FC
2643(W layer) When pushing layers onto the Perl I/O system, something other
2644than a colon or whitespace was seen between the elements of a layer list.
b4581f09
JH
2645If the previous attribute had a parenthesised parameter list, perhaps that
2646list was terminated too soon.
2647
2c86d456
DG
2648=item Invalid strict version format (%s)
2649
fa816bf3 2650(F) A version number did not meet the "strict" criteria for versions.
2c86d456
DG
2651A "strict" version number is a positive decimal number (integer or
2652decimal-fraction) without exponentiation or else a dotted-decimal
2653v-string with a leading 'v' character and at least three components.
a6485a24 2654The parenthesized text indicates which criteria were not met.
2c86d456
DG
2655See the L<version> module for more details on allowed version formats.
2656
49704364 2657=item Invalid type '%s' in %s
96e4d5b1 2658
49704364
LW
2659(F) The given character is not a valid pack or unpack type.
2660See L<perlfunc/pack>.
6728c851 2661
49704364 2662(W) The given character is not a valid pack or unpack type but used to be
75b44862 2663silently ignored.
96e4d5b1 2664
2c86d456
DG
2665=item Invalid version format (%s)
2666
fa816bf3 2667(F) A version number did not meet the "lax" criteria for versions.
2c86d456
DG
2668A "lax" version number is a positive decimal number (integer or
2669decimal-fraction) without exponentiation or else a dotted-decimal
fa816bf3
FC
2670v-string. If the v-string has fewer than three components, it
2671must have a leading 'v' character. Otherwise, the leading 'v' is
2672optional. Both decimal and dotted-decimal versions may have a
2673trailing "alpha" component separated by an underscore character
2674after a fractional or dotted-decimal component. The parenthesized
2675text indicates which criteria were not met. See the L<version> module
2676for more details on allowed version formats.
46314c13 2677
798ae1b7
DG
2678=item Invalid version object
2679
fa816bf3
FC
2680(F) The internal structure of the version object was invalid.
2681Perhaps the internals were modified directly in some way or
2682an arbitrary reference was blessed into the "version" class.
798ae1b7 2683
cd209d9d 2684=item In '(*VERB...)', the '(' and '*' must be adjacent in regex;
e0e4a6e3 2685marked by S<<-- HERE> in m/%s/
675fa9ff 2686
cd209d9d 2687(F) The two-character sequence C<"(*"> in
675fa9ff
FC
2688this context in a regular expression pattern should be an
2689indivisible token, with nothing intervening between the C<"(">
cd209d9d 2690and the C<"*">, but you separated them.
675fa9ff 2691
a0d0e21e
LW
2692=item ioctl is not implemented
2693
2694(F) Your machine apparently doesn't implement ioctl(), which is pretty
2695strange for a machine that supports C.
2696
c289d2f7
JH
2697=item ioctl() on unopened %s
2698
2699(W unopened) You tried ioctl() on a filehandle that was never opened.
34b6fd5e 2700Check your control flow and number of arguments.
c289d2f7 2701
fe13d51d 2702=item IO layers (like '%s') unavailable
363c40c4
SB
2703
2704(F) Your Perl has not been configured to have PerlIO, and therefore
34b6fd5e 2705you cannot use IO layers. To have PerlIO, Perl must be configured
363c40c4
SB
2706with 'useperlio'.
2707
80cbd5ad
JH
2708=item IO::Socket::atmark not implemented on this architecture
2709
2710(F) Your machine doesn't implement the sockatmark() functionality,
34b6fd5e 2711neither as a system call nor an ioctl call (SIOCATMARK).
80cbd5ad 2712
4f650b80 2713=item $* is no longer supported
b4581f09 2714
4f650b80 2715(D deprecated, syntax) The special variable C<$*>, deprecated in older
ea9d9ebc 2716perls, has been removed as of 5.10.0 and is no longer supported. In
4f650b80
NC
2717previous versions of perl the use of C<$*> enabled or disabled multi-line
2718matching within a string.
4fd19576
B
2719
2720Instead of using C<$*> you should use the C</m> (and maybe C</s>) regexp
6903afa2
FC
2721modifiers. You can enable C</m> for a lexical scope (even a whole file)
2722with C<use re '/m'>. (In older versions: when C<$*> was set to a true value
570dedd4 2723then all regular expressions behaved as if they were written using C</m>.)
b4581f09 2724
8ae1fe26
RGS
2725=item $# is no longer supported
2726
a58ac25e 2727(D deprecated, syntax) The special variable C<$#>, deprecated in older
ea9d9ebc 2728perls, has been removed as of 5.10.0 and is no longer supported. You
a58ac25e 2729should use the printf/sprintf functions instead.
8ae1fe26 2730
ccf3535a 2731=item '%s' is not a code reference
6ad11d81 2732
6903afa2
FC
2733(W overload) The second (fourth, sixth, ...) argument of
2734overload::constant needs to be a code reference. Either
2735an anonymous subroutine, or a reference to a subroutine.
6ad11d81 2736
ccf3535a 2737=item '%s' is not an overloadable type
6ad11d81 2738
04a80ee0
RGS
2739(W overload) You tried to overload a constant type the overload package is
2740unaware of.
6ad11d81 2741
5a25739d
FC
2742=item -i used with no filenames on the command line, reading from STDIN
2743
2744(S inplace) The C<-i> option was passed on the command line, indicating
2745that the script is intended to edit files in place, but no files were
2746given. This is usually a mistake, since editing STDIN in place doesn't
2747make sense, and can be confusing because it can make perl look like
2748it is hanging when it is really just trying to read from STDIN. You
2749should either pass a filename to edit, or remove C<-i> from the command
2750line. See L<perlrun> for more details.
2751
aec0ef10 2752=item Junk on end of regexp in regex m/%s/
a0d0e21e
LW
2753
2754(P) The regular expression parser is confused.
2755
0953b66b
FC
2756=item keys on reference is experimental
2757
0773cb3e
FC
2758(S experimental::autoderef) C<keys> with a scalar argument is experimental
2759and may change or be removed in a future Perl version. If you want to
2760take the risk of using this feature, simply disable this warning:
0953b66b 2761
d401967c 2762 no warnings "experimental::autoderef";
0953b66b 2763
a0d0e21e
LW
2764=item Label not found for "last %s"
2765
be771a83
GS
2766(F) You named a loop to break out of, but you're not currently in a loop
2767of that name, not even if you count where you were called from. See
2768L<perlfunc/last>.
a0d0e21e
LW
2769
2770=item Label not found for "next %s"
2771
2772(F) You named a loop to continue, but you're not currently in a loop of
2773that name, not even if you count where you were called from. See
2774L<perlfunc/last>.
2775
2776=item Label not found for "redo %s"
2777
2778(F) You named a loop to restart, but you're not currently in a loop of
2779that name, not even if you count where you were called from. See
2780L<perlfunc/last>.
2781
85ab1d1d 2782=item leaving effective %s failed
5ff3f7a4 2783
85ab1d1d 2784(F) While under the C<use filetest> pragma, switching the real and
5ff3f7a4
GS
2785effective uids or gids failed.
2786
49704364
LW
2787=item length/code after end of string in unpack
2788
d7f8936a 2789(F) While unpacking, the string buffer was already used up when an unpack
6903afa2
FC
2790length/code combination tried to obtain more data. This results in
2791an undefined value for the length. See L<perlfunc/pack>.
49704364 2792
25e26107 2793=item length() used on %s (did you mean "scalar(%s)"?)
e508c8a4 2794
0d46a4e7
FC
2795(W syntax) You used length() on either an array or a hash when you
2796probably wanted a count of the items.
e508c8a4
MH
2797
2798Array size can be obtained by doing:
2799
2800 scalar(@array);
2801
2802The number of items in a hash can be obtained by doing:
2803
2804 scalar(keys %hash);
2805
f0e67a1d
Z
2806=item Lexing code attempted to stuff non-Latin-1 character into Latin-1 input
2807
d4fe7078
RS
2808(F) An extension is attempting to insert text into the current parse
2809(using L<lex_stuff_pvn|perlapi/lex_stuff_pvn> or similar), but tried to insert a character that
2810couldn't be part of the current input. This is an inherent pitfall
2811of the stuffing mechanism, and one of the reasons to avoid it. Where
6903afa2 2812it is necessary to stuff, stuffing only plain ASCII is recommended.
f0e67a1d
Z
2813
2814=item Lexing code internal error (%s)
2815
2816(F) Lexing code supplied by an extension violated the lexer's API in a
2817detectable way.
2818
69282e91 2819=item listen() on closed socket %s
a0d0e21e 2820
be771a83
GS
2821(W closed) You tried to do a listen on a closed socket. Did you forget
2822to check the return value of your socket() call? See
2823L<perlfunc/listen>.
a0d0e21e 2824
6651ba0b
FC
2825=item List form of piped open not implemented
2826
2827(F) On some platforms, notably Windows, the three-or-more-arguments
2828form of C<open> does not support pipes, such as C<open($pipe, '|-', @args)>.
2829Use the two-argument C<open($pipe, '|prog arg1 arg2...')> form instead.
2830
b35b96b6
JH
2831=item localtime(%f) failed
2832
2833(W overflow) You called C<localtime> with a number that it could not handle:
2834too large, too small, or NaN. The returned value is C<undef>.
2835
bcd05b94 2836=item localtime(%f) too large
8b56d6ff 2837
e9200be3 2838(W overflow) You called C<localtime> with a number that was larger
fc003d4b 2839than it can reliably handle and C<localtime> probably returned the
6903afa2 2840wrong date. This warning is also triggered with NaN (the special
fc003d4b
MS
2841not-a-number value).
2842
bcd05b94 2843=item localtime(%f) too small
fc003d4b 2844
e9200be3 2845(W overflow) You called C<localtime> with a number that was smaller
fc003d4b 2846than it can reliably handle and C<localtime> probably returned the
e7a1a147 2847wrong date.
8b56d6ff 2848
58e23c8d 2849=item Lookbehind longer than %d not implemented in regex m/%s/
b45f050a
JF
2850
2851(F) There is currently a limit on the length of string which lookbehind can
6903afa2 2852handle. This restriction may be eased in a future release.
2e50fd82 2853
b88df990
NC
2854=item Lost precision when %s %f by 1
2855
e63e8a91
FC
2856(W imprecision) The value you attempted to increment or decrement by one
2857is too large for the underlying floating point representation to store
2858accurately, hence the target of C<++> or C<--> is unchanged. Perl issues this
2859warning because it has already switched from integers to floating point
2860when values are too large for integers, and now even floating point is
2861insufficient. You may wish to switch to using L<Math::BigInt> explicitly.
b88df990 2862
93fad930 2863=item lstat() on filehandle%s
2f7da168
RK
2864
2865(W io) You tried to do an lstat on a filehandle. What did you mean
2866by that? lstat() makes sense only on filenames. (Perl did a fstat()
2867instead on the filehandle.)
2868
345d70e3 2869=item lvalue attribute %s already-defined subroutine
bb3abb05 2870
345d70e3
FC
2871(W misc) Although L<attributes.pm|attributes> allows this, turning the lvalue
2872attribute on or off on a Perl subroutine that is already defined
2873does not always work properly. It may or may not do what you
2874want, depending on what code is inside the subroutine, with exact
2875details subject to change between Perl versions. Only do this
2876if you really know what you are doing.
bb3abb05 2877
885ef6f5
GG
2878=item lvalue attribute ignored after the subroutine has been defined
2879
345d70e3
FC
2880(W misc) Using the C<:lvalue> declarative syntax to make a Perl
2881subroutine an lvalue subroutine after it has been defined is
2882not permitted. To make the subroutine an lvalue subroutine,
2883add the lvalue attribute to the definition, or put the C<sub
2884foo :lvalue;> declaration before the definition.
2885
2886See also L<attributes.pm|attributes>.
885ef6f5 2887
6f1b3ab0
FC
2888=item Magical list constants are not supported
2889
2890(F) You assigned a magical array to a stash element, and then tried
2891to use the subroutine from the same slot. You are asking Perl to do
2892something it cannot do, details subject to change between Perl versions.
2893
2db62bbc 2894=item Malformed integer in [] in pack
49704364 2895
2db62bbc 2896(F) Between the brackets enclosing a numeric repeat count only digits
49704364
LW
2897are permitted. See L<perlfunc/pack>.
2898
2899=item Malformed integer in [] in unpack
2900
2db62bbc 2901(F) Between the brackets enclosing a numeric repeat count only digits
49704364
LW
2902are permitted. See L<perlfunc/pack>.
2903
6df41af2
GS
2904=item Malformed PERLLIB_PREFIX
2905
2906(F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form
2907
2908 prefix1;prefix2
2909
2910or
6df41af2
GS
2911 prefix1 prefix2
2912
be771a83
GS
2913with nonempty prefix1 and prefix2. If C<prefix1> is indeed a prefix of
2914a builtin library search path, prefix2 is substituted. The error may
2915appear if components are not found, or are too long. See
fecfaeb8 2916"PERLLIB_PREFIX" in L<perlos2>.
6df41af2 2917
2f758a16
ST
2918=item Malformed prototype for %s: %s
2919
d37a9538
ST
2920(F) You tried to use a function with a malformed prototype. The
2921syntax of function prototypes is given a brief compile-time check for
2922obvious errors like invalid characters. A more rigorous check is run
2923when the function is called.
30d9c59b
Z
2924Perhaps the function's author was trying to write a subroutine signature
2925but didn't enable that feature first (C<use feature 'signatures'>),
2926so the signature was instead interpreted as a bad prototype.
2f758a16 2927
ba210ebe
JH
2928=item Malformed UTF-8 character (%s)
2929
4d6f11e5 2930(S utf8)(F) Perl detected a string that didn't comply with UTF-8
2575c402 2931encoding rules, even though it had the UTF8 flag on.
ba210ebe 2932
2575c402
JW
2933One possible cause is that you set the UTF8 flag yourself for data that
2934you thought to be in UTF-8 but it wasn't (it was for example legacy
6903afa2 29358-bit data). To guard against this, you can use Encode::decode_utf8.
2575c402
JW
2936
2937If you use the C<:encoding(UTF-8)> PerlIO layer for input, invalid byte
2938sequences are handled gracefully, but if you use C<:utf8>, the flag is
2939set without validating the data, possibly resulting in this error
2940message.
2941
2942See also L<Encode/"Handling Malformed Data">.
901b21bf 2943
107160e2
KW
2944=item Malformed UTF-8 character immediately after '%s'
2945
2946(F) You said C<use utf8>, but the program file doesn't comply with UTF-8
2947encoding rules. The message prints out the properly encoded characters
2948just before the first bad one. If C<utf8> warnings are enabled, a
2949warning is generated that gives more details about the type of
2950malformation.
2951
bde9e88d 2952=item Malformed UTF-8 returned by \N{%s} immediately after '%s'
ff3f963a
KW
2953
2954(F) The charnames handler returned malformed UTF-8.
2955
4a5d3a93
FC
2956=item Malformed UTF-8 string in '%c' format in unpack
2957
2958(F) You tried to unpack something that didn't comply with UTF-8 encoding
2959rules and perl was unable to guess how to make more progress.
2960
f337b084
TH
2961=item Malformed UTF-8 string in pack
2962
2963(F) You tried to pack something that didn't comply with UTF-8 encoding
2964rules and perl was unable to guess how to make more progress.
2965
2966=item Malformed UTF-8 string in unpack
2967
2968(F) You tried to unpack something that didn't comply with UTF-8 encoding
2969rules and perl was unable to guess how to make more progress.
2970
4a5d3a93 2971=item Malformed UTF-16 surrogate
f337b084 2972
4a5d3a93
FC
2973(F) Perl thought it was reading UTF-16 encoded character data but while
2974doing it Perl met a malformed Unicode surrogate.
2975
30d9c59b
Z
2976=item Mandatory parameter follows optional parameter
2977
2978(F) In a subroutine signature, you wrote something like "$a = undef,
2979$b", making an earlier parameter optional and a later one mandatory.
2980Parameters are filled from left to right, so it's impossible for the
2981caller to omit an earlier one and pass a later one. If you want to act
2982as if the parameters are filled from right to left, declare the rightmost
2983optional and then shuffle the parameters around in the subroutine's body.
2984
2d88a86a
KW
2985=item Matched non-Unicode code point 0x%X against Unicode property; may
2986not be portable
2987
2988(S non_unicode) Perl allows strings to contain a superset of
2989Unicode code points; each code point may be as large as what is storable
2990in an unsigned integer on your system, but these may not be accepted by
2991other languages/systems. This message occurs when you matched a string
2992containing such a code point against a regular expression pattern, and
2993the code point was matched against a Unicode property, C<\p{...}> or
2994C<\P{...}>. Unicode properties are only defined on Unicode code points,
2995so the result of this match is undefined by Unicode, but Perl (starting
2996in v5.20) treats non-Unicode code points as if they were typical
2997unassigned Unicode ones, and matched this one accordingly. Whether a
2998given property matches these code points or not is specified in
2999L<perluniprops/Properties accessible through \p{} and \P{}>.
3000
3001This message is suppressed (unless it has been made fatal) if it is
3002immaterial to the results of the match if the code point is Unicode or
3003not. For example, the property C<\p{ASCII_Hex_Digit}> only can match
3004the 22 characters C<[0-9A-Fa-f]>, so obviously all other code points,
3005Unicode or not, won't match it. (And C<\P{ASCII_Hex_Digit}> will match
3006every code point except these 22.)
3007
3008Getting this message indicates that the outcome of the match arguably
3009should have been the opposite of what actually happened. If you think
3010that is the case, you may wish to make the C<non_unicode> warnings
3011category fatal; if you agree with Perl's decision, you may wish to turn
3012off this category.
3013
3014See L<perlunicode/Beyond Unicode code points> for more information.
3015
e0e4a6e3
FC
3016=item %s matches null string many times in regex; marked by S<<-- HERE> in
3017m/%s/
4a5d3a93
FC
3018
3019(W regexp) The pattern you've specified would be an infinite loop if the
e0e4a6e3 3020regular expression engine didn't specifically check for that. The S<<-- HERE>
9e3ec65c 3021shows whereabouts in the regular expression the problem was discovered.
4a5d3a93 3022See L<perlre>.
f337b084 3023
de42a5a9 3024=item Maximal count of pending signals (%u) exceeded
2563cec5 3025
6903afa2 3026(F) Perl aborted due to too high a number of signals pending. This
2563cec5
IZ
3027usually indicates that your operating system tried to deliver signals
3028too fast (with a very high priority), starving the perl process from
3029resources it would need to reach a point where it can process signals
6903afa2 3030safely. (See L<perlipc/"Deferred Signals (Safe Signals)">.)
2563cec5 3031
25f58aea
PN
3032=item "%s" may clash with future reserved word
3033
3034(W) This warning may be due to running a perl5 script through a perl4
3035interpreter, especially if the word that is being warned about is
3036"use" or "my".
3037
0d2487cd 3038=item '%' may not be used in pack
6df41af2
GS
3039
3040(F) You can't pack a string by supplying a checksum, because the
be771a83
GS
3041checksumming process loses information, and you can't go the other way.
3042See L<perlfunc/unpack>.
6df41af2 3043
a0d0e21e
LW
3044=item Method for operation %s not found in package %s during blessing
3045
3046(F) An attempt was made to specify an entry in an overloading table that
e7ea3e70 3047doesn't resolve to a valid subroutine. See L<overload>.
a0d0e21e 3048
3cdd684c
TP
3049=item Method %s not permitted
3050
3051See Server error.
3052
a0d0e21e
LW
3053=item Might be a runaway multi-line %s string starting on line %d
3054
3055(S) An advisory indicating that the previous error may have been caused
3056by a missing delimiter on a string or pattern, because it eventually
3057ended earlier on the current line.
3058
3059=item Misplaced _ in number
3060
d4ced10d
JH
3061(W syntax) An underscore (underbar) in a numeric constant did not
3062separate two digits.
a0d0e21e 3063
7baa4690
HS
3064=item Missing argument in %s
3065
3664866e
AB
3066(W missing) You called a function with fewer arguments than other
3067arguments you supplied indicated would be needed.
3068
3069Currently only emitted when a printf-type format required more
3070arguments than were supplied, but might be used in the future for
3071other cases where we can statically determine that arguments to
3072functions are missing, e.g. for the L<perlfunc/pack> function.
7baa4690 3073
9e81e6a1
RGS
3074=item Missing argument to -%c
3075
3076(F) The argument to the indicated command line switch must follow
3077immediately after the switch, without intervening spaces.
3078
ff3f963a 3079=item Missing braces on \N{}
423cee85 3080
e0e4a6e3 3081=item Missing braces on \N{} in regex; marked by S<<-- HERE> in m/%s/
aec0ef10 3082
4a2d328f 3083(F) Wrong syntax of character name literal C<\N{charname}> within
532cb70d
FC
3084double-quotish context. This can also happen when there is a space
3085(or comment) between the C<\N> and the C<{> in a regex with the C</x> modifier.
3086This modifier does not change the requirement that the brace immediately
3087follow the C<\N>.
423cee85 3088
f0a2b745
KW
3089=item Missing braces on \o{}
3090
3091(F) A C<\o> must be followed immediately by a C<{> in double-quotish context.
3092
a0d0e21e
LW
3093=item Missing comma after first argument to %s function
3094
3095(F) While certain functions allow you to specify a filehandle or an
3096"indirect object" before the argument list, this ain't one of them.
3097
06eaf0bc
GS
3098=item Missing command in piped open
3099
be771a83
GS
3100(W pipe) You used the C<open(FH, "| command")> or
3101C<open(FH, "command |")> construction, but the command was missing or
3102blank.
06eaf0bc 3103
961ce445
RGS
3104=item Missing control char name in \c
3105
3106(F) A double-quoted string ended with "\c", without the required control
3107character name.
3108
591f5ca2
FC
3109=item Missing ']' in prototype for %s : %s
3110
bfe11873 3111(W illegalproto) A grouping was started with C<[> but never closed with C<]>.
591f5ca2 3112
8767b1ab 3113=item Missing name in "%s sub"
6df41af2 3114
87444db5 3115(F) The syntax for lexically scoped subroutines requires that
be771a83 3116they have a name with which they can be found.
6df41af2
GS
3117
3118=item Missing $ on loop variable
3119
be771a83
GS
3120(F) Apparently you've been programming in B<csh> too much. Variables
3121are always mentioned with the $ in Perl, unlike in the shells, where it
3122can vary from one line to the next.
6df41af2 3123
cc507455 3124=item (Missing operator before %s?)
748a9306 3125
56da5a46
RGS
3126(S syntax) This is an educated guess made in conjunction with the message
3127"%s found where operator expected". Often the missing operator is a comma.
748a9306 3128
f51551f7
FC
3129=item Missing or undefined argument to require
3130
3131(F) You tried to call require with no argument or with an undefined
3132value as an argument. Require expects either a package name or a
3133file-specification as an argument. See L<perlfunc/require>.
3134
e0e4a6e3 3135=item Missing right brace on \%c{} in regex; marked by S<<-- HERE> in m/%s/
ab13f0c7 3136
ff3f963a
KW
3137(F) Missing right brace in C<\x{...}>, C<\p{...}>, C<\P{...}>, or C<\N{...}>.
3138
4a68bf9d 3139=item Missing right brace on \N{} or unescaped left brace after \N
ff3f963a 3140
d32207c9
FC
3141(F) C<\N> has two meanings.
3142
3143The traditional one has it followed by a name enclosed in braces,
3144meaning the character (or sequence of characters) given by that
fa816bf3 3145name. Thus C<\N{ASTERISK}> is another way of writing C<*>, valid in both
d32207c9
FC
3146double-quoted strings and regular expression patterns. In patterns,
3147it doesn't have the meaning an unescaped C<*> does.
3148
3149Starting in Perl 5.12.0, C<\N> also can have an additional meaning (only)
3150in patterns, namely to match a non-newline character. (This is short
3151for C<[^\n]>, and like C<.> but is not affected by the C</s> regex modifier.)
3152
3153This can lead to some ambiguities. When C<\N> is not followed immediately
3154by a left brace, Perl assumes the C<[^\n]> meaning. Also, if the braces
3155form a valid quantifier such as C<\N{3}> or C<\N{5,}>, Perl assumes that this
3156means to match the given quantity of non-newlines (in these examples,
31573; and 5 or more, respectively). In all other case, where there is a
3158C<\N{> and a matching C<}>, Perl assumes that a character name is desired.
3159
3160However, if there is no matching C<}>, Perl doesn't know if it was
3161mistakenly omitted, or if C<[^\n]{> was desired, and raises this error.
3162If you meant the former, add the right brace; if you meant the latter,
3163escape the brace with a backslash, like so: C<\N\{>
ab13f0c7 3164
d98d5fff 3165=item Missing right curly or square bracket
a0d0e21e 3166
be771a83
GS
3167(F) The lexer counted more opening curly or square brackets than closing
3168ones. As a general rule, you'll find it's missing near the place you
3169were last editing.
a0d0e21e 3170
6df41af2
GS
3171=item (Missing semicolon on previous line?)
3172
56da5a46
RGS
3173(S syntax) This is an educated guess made in conjunction with the message
3174"%s found where operator expected". Don't automatically put a semicolon on
6df41af2
GS
3175the previous line just because you saw this message.
3176
a0d0e21e
LW
3177=item Modification of a read-only value attempted
3178
3179(F) You tried, directly or indirectly, to change the value of a
5f05dabc 3180constant. You didn't, of course, try "2 = 1", because the compiler
a0d0e21e
LW
3181catches that. But an easy way to do the same thing is:
3182
3183 sub mod { $_[0] = 1 }
3184 mod(2);
3185
3186Another way is to assign to a substr() that's off the end of the string.
3187
c5674021
PDF
3188Yet another way is to assign to a C<foreach> loop I<VAR> when I<VAR>
3189is aliased to a constant in the look I<LIST>:
3190
b7e4ecc1
FC
3191 $x = 1;
3192 foreach my $n ($x, 2) {
3193 $n *= 2; # modifies the $x, but fails on attempt to
3194 } # modify the 2
c5674021 3195
7a4340ed 3196=item Modification of non-creatable array value attempted, %s
a0d0e21e
LW
3197
3198(F) You tried to make an array value spring into existence, and the
3199subscript was probably negative, even counting from end of the array
3200backwards.
3201
7a4340ed 3202=item Modification of non-creatable hash value attempted, %s
a0d0e21e 3203
be771a83
GS
3204(P) You tried to make a hash value spring into existence, and it
3205couldn't be created for some peculiar reason.
a0d0e21e
LW
3206
3207=item Module name must be constant
3208
3209(F) Only a bare module name is allowed as the first argument to a "use".
3210
be98fb35 3211=item Module name required with -%c option
6df41af2 3212
be98fb35
GS
3213(F) The C<-M> or C<-m> options say that Perl should load some module, but
3214you omitted the name of the module. Consult L<perlrun> for full details
3215about C<-M> and C<-m>.
6df41af2 3216
fe13d51d 3217=item More than one argument to '%s' open
ed9aa3b7 3218
6903afa2 3219(F) The C<open> function has been asked to open multiple files. This
ed9aa3b7
SG
3220can happen if you are trying to open a pipe to a command that takes a
3221list of arguments, but have forgotten to specify a piped open mode.
3222See L<perlfunc/open> for details.
3223
85396b18
FC
3224=item mprotect for COW string %p %u failed with %d
3225
3226(S) You compiled perl with B<-D>PERL_DEBUG_READONLY_COW (see
3227L<perlguts/"Copy on Write">), but a shared string buffer
3228could not be made read-only.
3229
92951bce
FC
3230=item mprotect for %p %u failed with %d
3231
85396b18
FC
3232(S) You compiled perl with B<-D>PERL_DEBUG_READONLY_OPS (see L<perlhacktips>),
3233but an op tree could not be made read-only.
3234
3235=item mprotect RW for COW string %p %u failed with %d
3236
3237(S) You compiled perl with B<-D>PERL_DEBUG_READONLY_COW (see
3238L<perlguts/"Copy on Write">), but a read-only shared string
3239buffer could not be made mutable.
3240
92951bce
FC
3241=item mprotect RW for %p %u failed with %d
3242
3243(S) You compiled perl with B<-D>PERL_DEBUG_READONLY_OPS (see
85396b18
FC
3244L<perlhacktips>), but a read-only op tree could not be made
3245mutable before freeing the ops.
92951bce 3246
a0d0e21e
LW
3247=item msg%s not implemented
3248
3249(F) You don't have System V message IPC on your system.
3250
3251=item Multidimensional syntax %s not supported
3252
75b44862
GS
3253(W syntax) Multidimensional arrays aren't written like C<$foo[1,2,3]>.
3254They're written like C<$foo[1][2][3]>, as in C.
8b1a09fc 3255
49704364 3256=item '/' must follow a numeric type in unpack
6df41af2 3257
49704364
LW
3258(F) You had an unpack template that contained a '/', but this did not
3259follow some unpack specification producing a numeric value.
3260See L<perlfunc/pack>.
6df41af2
GS
3261
3262=item "my sub" not yet implemented
3263
be771a83
GS
3264(F) Lexically scoped subroutines are not yet implemented. Don't try
3265that yet.
6df41af2 3266
5a25739d
FC
3267=item "my %s" used in sort comparison
3268
3269(W syntax) The package variables $a and $b are used for sort comparisons.
3270You used $a or $b in as an operand to the C<< <=> >> or C<cmp> operator inside a
3271sort comparison block, and the variable had earlier been declared as a
3272lexical variable. Either qualify the sort variable with the package
3273name, or rename the lexical variable.
3274
fd1b7234 3275=item "my" variable %s can't be in a package
6df41af2 3276
be771a83
GS
3277(F) Lexically scoped variables aren't in a package, so it doesn't make
3278sense to try to declare one with a package qualifier on the front. Use
3279local() if you want to localize a package variable.
09bef843 3280
8149aa9f
FC
3281=item Name "%s::%s" used only once: possible typo
3282
c59aba6c
FC
3283(W once) Typographical errors often show up as unique variable
3284names. If you had a good reason for having a unique name, then
3285just mention it again somehow to suppress the message. The C<our>
08a33b6b 3286declaration is also provided for this purpose.
c59aba6c 3287
66a1f5ec
FC
3288NOTE: This warning detects package symbols that have been used
3289only once. This means lexical variables will never trigger this
3290warning. It also means that all of the package variables $c, @c,
3291%c, as well as *c, &c, sub c{}, c(), and c (the filehandle or
c59aba6c
FC
3292format) are considered the same; if a program uses $c only once
3293but also uses any of the others it will not trigger this warning.
3294Symbols beginning with an underscore and symbols using special
3295identifiers (q.v. L<perldata>) are exempt from this warning.
8149aa9f 3296
e0e4a6e3 3297=item Need exactly 3 octal digits in regex; marked by S<<-- HERE> in m/%s/
0d0b4b3b
KW
3298
3299(F) Within S<C<(?[ ])>>, all constants interpreted as octal need to be
3300exactly 3 digits long. This helps catch some ambiguities. If your
3301constant is too short, add leading zeros, like
3302
3303 (?[ [ \078 ] ]) # Syntax error!
3304 (?[ [ \0078 ] ]) # Works
3305 (?[ [ \007 8 ] ]) # Clearer
3306
3307The maximum number this construct can express is C<\777>. If you
675fa9ff
FC
3308need a larger one, you need to use L<\o{}|perlrebackslash/Octal escapes> instead. If you meant
3309two separate things, you need to separate them:
0d0b4b3b
KW
3310
3311 (?[ [ \7776 ] ]) # Syntax error!
3312 (?[ [ \o{7776} ] ]) # One meaning
3313 (?[ [ \777 6 ] ]) # Another meaning
3314 (?[ [ \777 \006 ] ]) # Still another
3315
49704364
LW
3316=item Negative '/' count in unpack
3317
3318(F) The length count obtained from a length/code unpack operation was
3319negative. See L<perlfunc/pack>.
3320
a0d0e21e
LW
3321=item Negative length