3 perldiag - various Perl diagnostics
7 These messages are classified as follows (listed in increasing order of
10 (W) A warning (optional).
11 (D) A deprecation (optional).
12 (S) A severe warning (default).
13 (F) A fatal error (trappable).
14 (P) An internal error you should never see (trappable).
15 (X) A very fatal error (nontrappable).
16 (A) An alien error message (not generated by Perl).
18 The majority of messages from the first three classifications above
19 (W, D & S) can be controlled using the C<warnings> pragma.
21 If a message can be controlled by the C<warnings> pragma, its warning
22 category is included with the classification letter in the description
25 Optional warnings are enabled by using the C<warnings> pragma or the B<-w>
26 and B<-W> switches. Warnings may be captured by setting C<$SIG{__WARN__}>
27 to a reference to a routine that will be called on each warning instead
28 of printing it. See L<perlvar>.
30 Default warnings are always enabled unless they are explicitly disabled
31 with the C<warnings> pragma or the B<-X> switch.
33 Trappable errors may be trapped using the eval operator. See
34 L<perlfunc/eval>. In almost all cases, warnings may be selectively
35 disabled or promoted to fatal errors using the C<warnings> pragma.
38 The messages are in alphabetical order, without regard to upper or
39 lower-case. Some of these messages are generic. Spots that vary are
40 denoted with a %s or other printf-style escape. These escapes are
41 ignored by the alphabetical order, as are all characters other than
42 letters. To look up your message, just ignore anything that is not a
47 =item A thread exited while %d other threads were still running
49 (W) When using threaded Perl, a thread (not necessarily the main
50 thread) exited while there were still other threads running.
51 Usually it's a good idea to first collect the return values of the
52 created threads by joining them, and only then exit from then main
53 thread. See L<threads>.
55 =item accept() on closed socket %s
57 (W closed) You tried to do an accept on a closed socket. Did you forget
58 to check the return value of your socket() call? See
61 =item Allocation too large: %lx
63 (X) You can't allocate more than 64K on an MS-DOS machine.
65 =item '!' allowed only after types %s
67 (F) The '!' is allowed in pack() and unpack() only after certain types.
70 =item Ambiguous call resolved as CORE::%s(), qualify as such or use &
72 (W ambiguous) A subroutine you have declared has the same name as a Perl
73 keyword, and you have used the name without qualification for calling
74 one or the other. Perl decided to call the builtin because the
75 subroutine is not imported.
77 To force interpretation as a subroutine call, either put an ampersand
78 before the subroutine name, or qualify the name with its package.
79 Alternatively, you can import the subroutine (or pretend that it's
80 imported with the C<use subs> pragma).
82 To silently interpret it as the Perl operator, use the C<CORE::> prefix
83 on the operator (e.g. C<CORE::log($x)>) or declare the subroutine
84 to be an object method (see L<perlsub/"Subroutine Attributes"> or
87 =item Ambiguous range in transliteration operator
89 (F) You wrote something like C<tr/a-z-0//> which doesn't mean anything at
90 all. To include a C<-> character in a transliteration, put it either
91 first or last. (In the past, C<tr/a-z-0//> was synonymous with
92 C<tr/a-y//>, which was probably not what you would have expected.)
94 =item Ambiguous use of %s resolved as %s
96 (W ambiguous)(S) You said something that may not be interpreted the way
97 you thought. Normally it's pretty easy to disambiguate it by supplying
98 a missing quote, operator, parenthesis pair or declaration.
100 =item '|' and '<' may not both be specified on command line
102 (F) An error peculiar to VMS. Perl does its own command line
103 redirection, and found that STDIN was a pipe, and that you also tried to
104 redirect STDIN using '<'. Only one STDIN stream to a customer, please.
106 =item '|' and '>' may not both be specified on command line
108 (F) An error peculiar to VMS. Perl does its own command line
109 redirection, and thinks you tried to redirect stdout both to a file and
110 into a pipe to another command. You need to choose one or the other,
111 though nothing's stopping you from piping into a program or Perl script
112 which 'splits' output into two streams, such as
114 open(OUT,">$ARGV[0]") or die "Can't write to $ARGV[0]: $!";
121 =item Applying %s to %s will act on scalar(%s)
123 (W misc) The pattern match (C<//>), substitution (C<s///>), and
124 transliteration (C<tr///>) operators work on scalar values. If you apply
125 one of them to an array or a hash, it will convert the array or hash to
126 a scalar value -- the length of an array, or the population info of a
127 hash -- and then work on that scalar value. This is probably not what
128 you meant to do. See L<perlfunc/grep> and L<perlfunc/map> for
131 =item Args must match #! line
133 (F) The setuid emulator requires that the arguments Perl was invoked
134 with match the arguments specified on the #! line. Since some systems
135 impose a one-argument limit on the #! line, try combining switches;
136 for example, turn C<-w -U> into C<-wU>.
138 =item Arg too short for msgsnd
140 (F) msgsnd() requires a string at least as long as sizeof(long).
142 =item %s argument is not a HASH or ARRAY element
144 (F) The argument to exists() must be a hash or array element, such as:
149 =item %s argument is not a HASH or ARRAY element or slice
151 (F) The argument to delete() must be either a hash or array element,
157 or a hash or array slice, such as:
159 @foo[$bar, $baz, $xyzzy]
160 @{$ref->[12]}{"susie", "queue"}
162 =item %s argument is not a subroutine name
164 (F) The argument to exists() for C<exists &sub> must be a subroutine
165 name, and not a subroutine call. C<exists &sub()> will generate this
168 =item Argument "%s" isn't numeric%s
170 (W numeric) The indicated string was fed as an argument to an operator
171 that expected a numeric value instead. If you're fortunate the message
172 will identify which operator was so unfortunate.
174 =item Array @%s missing the @ in argument %d of %s()
176 (D deprecated) Really old Perl let you omit the @ on array names in some
177 spots. This is now heavily deprecated.
179 =item assertion botched: %s
181 (P) The malloc package that comes with Perl had an internal failure.
183 =item Assertion failed: file "%s"
185 (P) A general assertion failed. The file in question must be examined.
187 =item Assignment to both a list and a scalar
189 (F) If you assign to a conditional operator, the 2nd and 3rd arguments
190 must either both be scalars or both be lists. Otherwise Perl won't
191 know which context to supply to the right side.
193 =item Attempt to access disallowed key '%s' in a restricted hash
195 (F) The failing code has attempted to get or set a key which is not in
196 the current set of allowed keys of a restricted hash.
198 =item Attempt to clear a restricted hash
200 (F) It is currently not allowed to clear a restricted hash, even if the
201 new hash would contain the same keys as before. This may change in
204 =item Attempt to delete readonly key '%s' from a restricted hash
206 (F) The failing code attempted to delete a key whose value has been
207 declared readonly from a restricted hash.
209 =item Attempt to delete disallowed key '%s' from a restricted hash
211 (F) The failing code attempted to delete from a restricted hash a key
212 which is not in its key set.
214 =item Attempt to bless into a reference
216 (F) The CLASSNAME argument to the bless() operator is expected to be
217 the name of the package to bless the resulting object into. You've
218 supplied instead a reference to something: perhaps you wrote
224 bless $self, ref($proto) || $proto;
226 If you actually want to bless into the stringified version
227 of the reference supplied, you need to stringify it yourself, for
230 bless $self, "$proto";
232 =item Attempt to free non-arena SV: 0x%lx
234 (P internal) All SV objects are supposed to be allocated from arenas
235 that will be garbage collected on exit. An SV was discovered to be
236 outside any of those arenas.
238 =item Attempt to free nonexistent shared string
240 (P internal) Perl maintains a reference counted internal table of
241 strings to optimize the storage and access of hash keys and other
242 strings. This indicates someone tried to decrement the reference count
243 of a string that can no longer be found in the table.
245 =item Attempt to free temp prematurely
247 (W debugging) Mortalized values are supposed to be freed by the
248 free_tmps() routine. This indicates that something else is freeing the
249 SV before the free_tmps() routine gets a chance, which means that the
250 free_tmps() routine will be freeing an unreferenced scalar when it does
253 =item Attempt to free unreferenced glob pointers
255 (P internal) The reference counts got screwed up on symbol aliases.
257 =item Attempt to free unreferenced scalar
259 (W internal) Perl went to decrement the reference count of a scalar to
260 see if it would go to 0, and discovered that it had already gone to 0
261 earlier, and should have been freed, and in fact, probably was freed.
262 This could indicate that SvREFCNT_dec() was called too many times, or
263 that SvREFCNT_inc() was called too few times, or that the SV was
264 mortalized when it shouldn't have been, or that memory has been
267 =item Attempt to join self
269 (F) You tried to join a thread from within itself, which is an
270 impossible task. You may be joining the wrong thread, or you may need
271 to move the join() to some other thread.
273 =item Attempt to pack pointer to temporary value
275 (W pack) You tried to pass a temporary value (like the result of a
276 function, or a computed expression) to the "p" pack() template. This
277 means the result contains a pointer to a location that could become
278 invalid anytime, even before the end of the current statement. Use
279 literals or global values as arguments to the "p" pack() template to
282 =item Attempt to use reference as lvalue in substr
284 (W substr) You supplied a reference as the first argument to substr()
285 used as an lvalue, which is pretty strange. Perhaps you forgot to
286 dereference it first. See L<perlfunc/substr>.
288 =item Bad arg length for %s, is %d, should be %s
290 (F) You passed a buffer of the wrong size to one of msgctl(), semctl()
291 or shmctl(). In C parlance, the correct sizes are, respectively,
292 S<sizeof(struct msqid_ds *)>, S<sizeof(struct semid_ds *)>, and
293 S<sizeof(struct shmid_ds *)>.
295 =item Bad evalled substitution pattern
297 (F) You've used the C</e> switch to evaluate the replacement for a
298 substitution, but perl found a syntax error in the code to evaluate,
299 most likely an unexpected right brace '}'.
301 =item Bad filehandle: %s
303 (F) A symbol was passed to something wanting a filehandle, but the
304 symbol has no filehandle associated with it. Perhaps you didn't do an
305 open(), or did it in another package.
307 =item Bad free() ignored
309 (S malloc) An internal routine called free() on something that had never
310 been malloc()ed in the first place. Mandatory, but can be disabled by
311 setting environment variable C<PERL_BADFREE> to 0.
313 This message can be seen quite often with DB_File on systems with "hard"
314 dynamic linking, like C<AIX> and C<OS/2>. It is a bug of C<Berkeley DB>
315 which is left unnoticed if C<DB> uses I<forgiving> system malloc().
319 (P) One of the internal hash routines was passed a null HV pointer.
321 =item Bad index while coercing array into hash
323 (F) The index looked up in the hash found as the 0'th element of a
324 pseudo-hash is not legal. Index values must be at 1 or greater.
327 =item Badly placed ()'s
329 (A) You've accidentally run your script through B<csh> instead
330 of Perl. Check the #! line, or manually feed your script into
333 =item Bad name after %s::
335 (F) You started to name a symbol by using a package prefix, and then
336 didn't finish the symbol. In particular, you can't interpolate outside
345 $sym = "mypack::$var";
347 =item Bad realloc() ignored
349 (S malloc) An internal routine called realloc() on something that had
350 never been malloc()ed in the first place. Mandatory, but can be disabled
351 by setting environment variable C<PERL_BADFREE> to 1.
353 =item Bad symbol for array
355 (P) An internal request asked to add an array entry to something that
356 wasn't a symbol table entry.
358 =item Bad symbol for filehandle
360 (P) An internal request asked to add a filehandle entry to something
361 that wasn't a symbol table entry.
363 =item Bad symbol for hash
365 (P) An internal request asked to add a hash entry to something that
366 wasn't a symbol table entry.
368 =item Bareword found in conditional
370 (W bareword) The compiler found a bareword where it expected a
371 conditional, which often indicates that an || or && was parsed as part
372 of the last argument of the previous construct, for example:
376 It may also indicate a misspelled constant that has been interpreted as
379 use constant TYPO => 1;
380 if (TYOP) { print "foo" }
382 The C<strict> pragma is useful in avoiding such errors.
384 =item Bareword "%s" not allowed while "strict subs" in use
386 (F) With "strict subs" in use, a bareword is only allowed as a
387 subroutine identifier, in curly brackets or to the left of the "=>"
388 symbol. Perhaps you need to predeclare a subroutine?
390 =item Bareword "%s" refers to nonexistent package
392 (W bareword) You used a qualified bareword of the form C<Foo::>, but the
393 compiler saw no other uses of that namespace before that point. Perhaps
394 you need to predeclare a package?
396 =item BEGIN failed--compilation aborted
398 (F) An untrapped exception was raised while executing a BEGIN
399 subroutine. Compilation stops immediately and the interpreter is
402 =item BEGIN not safe after errors--compilation aborted
404 (F) Perl found a C<BEGIN {}> subroutine (or a C<use> directive, which
405 implies a C<BEGIN {}>) after one or more compilation errors had already
406 occurred. Since the intended environment for the C<BEGIN {}> could not
407 be guaranteed (due to the errors), and since subsequent code likely
408 depends on its correct operation, Perl just gave up.
410 =item \1 better written as $1
412 (W syntax) Outside of patterns, backreferences live on as variables.
413 The use of backslashes is grandfathered on the right-hand side of a
414 substitution, but stylistically it's better to use the variable form
415 because other Perl programmers will expect it, and it works better if
416 there are more than 9 backreferences.
418 =item Binary number > 0b11111111111111111111111111111111 non-portable
420 (W portable) The binary number you specified is larger than 2**32-1
421 (4294967295) and therefore non-portable between systems. See
422 L<perlport> for more on portability concerns.
424 =item bind() on closed socket %s
426 (W closed) You tried to do a bind on a closed socket. Did you forget to
427 check the return value of your socket() call? See L<perlfunc/bind>.
429 =item binmode() on closed filehandle %s
431 (W unopened) You tried binmode() on a filehandle that was never opened.
432 Check you control flow and number of arguments.
434 =item Bit vector size > 32 non-portable
436 (W portable) Using bit vector sizes larger than 32 is non-portable.
438 =item Bizarre copy of %s in %s
440 (P) Perl detected an attempt to copy an internal value that is not
443 =item B<-P> not allowed for setuid/setgid script
445 (F) The script would have to be opened by the C preprocessor by name,
446 which provides a race condition that breaks security.
448 =item Buffer overflow in prime_env_iter: %s
450 (W internal) A warning peculiar to VMS. While Perl was preparing to
451 iterate over %ENV, it encountered a logical name or symbol definition
452 which was too long, so it was truncated to the string shown.
454 =item Callback called exit
456 (F) A subroutine invoked from an external package via call_sv()
457 exited by calling exit.
459 =item %s() called too early to check prototype
461 (W prototype) You've called a function that has a prototype before the
462 parser saw a definition or declaration for it, and Perl could not check
463 that the call conforms to the prototype. You need to either add an
464 early prototype declaration for the subroutine in question, or move the
465 subroutine definition ahead of the call to get proper prototype
466 checking. Alternatively, if you are certain that you're calling the
467 function correctly, you may put an ampersand before the name to avoid
468 the warning. See L<perlsub>.
470 =item / cannot take a count
472 (F) You had an unpack template indicating a counted-length string, but
473 you have also specified an explicit size for the string. See
476 =item Can't bless non-reference value
478 (F) Only hard references may be blessed. This is how Perl "enforces"
479 encapsulation of objects. See L<perlobj>.
481 =item Can't call method "%s" in empty package "%s"
483 (F) You called a method correctly, and it correctly indicated a package
484 functioning as a class, but that package doesn't have ANYTHING defined
485 in it, let alone methods. See L<perlobj>.
487 =item Can't call method "%s" on an undefined value
489 (F) You used the syntax of a method call, but the slot filled by the
490 object reference or package name contains an undefined value. Something
491 like this will reproduce the error:
494 process $BADREF 1,2,3;
495 $BADREF->process(1,2,3);
497 =item Can't call method "%s" on unblessed reference
499 (F) A method call must know in what package it's supposed to run. It
500 ordinarily finds this out from the object reference you supply, but you
501 didn't supply an object reference in this case. A reference isn't an
502 object reference until it has been blessed. See L<perlobj>.
504 =item Can't call method "%s" without a package or object reference
506 (F) You used the syntax of a method call, but the slot filled by the
507 object reference or package name contains an expression that returns a
508 defined value which is neither an object reference nor a package name.
509 Something like this will reproduce the error:
512 process $BADREF 1,2,3;
513 $BADREF->process(1,2,3);
515 =item Can't chdir to %s
517 (F) You called C<perl -x/foo/bar>, but C</foo/bar> is not a directory
518 that you can chdir to, possibly because it doesn't exist.
520 =item Can't check filesystem of script "%s" for nosuid
522 (P) For some reason you can't check the filesystem of the script for
525 =item Can't coerce array into hash
527 (F) You used an array where a hash was expected, but the array has no
528 information on how to map from keys to array indices. You can do that
529 only with arrays that have a hash reference at index 0.
531 =item Can't coerce %s to integer in %s
533 (F) Certain types of SVs, in particular real symbol table entries
534 (typeglobs), can't be forced to stop being what they are. So you can't
544 but then $foo no longer contains a glob.
546 =item Can't coerce %s to number in %s
548 (F) Certain types of SVs, in particular real symbol table entries
549 (typeglobs), can't be forced to stop being what they are.
551 =item Can't coerce %s to string in %s
553 (F) Certain types of SVs, in particular real symbol table entries
554 (typeglobs), can't be forced to stop being what they are.
556 =item Can't create pipe mailbox
558 (P) An error peculiar to VMS. The process is suffering from exhausted
559 quotas or other plumbing problems.
561 =item Can't declare class for non-scalar %s in "%s"
563 (F) Currently, only scalar variables can be declared with a specific
564 class qualifier in a "my" or "our" declaration. The semantics may be
565 extended for other types of variables in future.
567 =item Can't declare %s in "%s"
569 (F) Only scalar, array, and hash variables may be declared as "my" or
570 "our" variables. They must have ordinary identifiers as names.
572 =item Can't do inplace edit: %s is not a regular file
574 (S inplace) You tried to use the B<-i> switch on a special file, such as
575 a file in /dev, or a FIFO. The file was ignored.
577 =item Can't do inplace edit on %s: %s
579 (S inplace) The creation of the new file failed for the indicated
582 =item Can't do inplace edit without backup
584 (F) You're on a system such as MS-DOS that gets confused if you try
585 reading from a deleted (but still opened) file. You have to say
586 C<-i.bak>, or some such.
588 =item Can't do inplace edit: %s would not be unique
590 (S inplace) Your filesystem does not support filenames longer than 14
591 characters and Perl was unable to create a unique filename during
592 inplace editing with the B<-i> switch. The file was ignored.
594 =item Can't do {n,m} with n > m in regex; marked by <-- HERE in m/%s/
596 (F) Minima must be less than or equal to maxima. If you really want your
597 regexp to match something 0 times, just put {0}. The <-- HERE shows in the
598 regular expression about where the problem was discovered. See L<perlre>.
600 =item Can't do setegid!
602 (P) The setegid() call failed for some reason in the setuid emulator of
605 =item Can't do seteuid!
607 (P) The setuid emulator of suidperl failed for some reason.
609 =item Can't do setuid
611 (F) This typically means that ordinary perl tried to exec suidperl to do
612 setuid emulation, but couldn't exec it. It looks for a name of the form
613 sperl5.000 in the same directory that the perl executable resides under
614 the name perl5.000, typically /usr/local/bin on Unix machines. If the
615 file is there, check the execute permissions. If it isn't, ask your
616 sysadmin why he and/or she removed it.
618 =item Can't do waitpid with flags
620 (F) This machine doesn't have either waitpid() or wait4(), so only
621 waitpid() without flags is emulated.
623 =item Can't emulate -%s on #! line
625 (F) The #! line specifies a switch that doesn't make sense at this
626 point. For example, it'd be kind of silly to put a B<-x> on the #!
629 =item Can't exec "%s": %s
631 (W exec) A system(), exec(), or piped open call could not execute the
632 named program for the indicated reason. Typical reasons include: the
633 permissions were wrong on the file, the file wasn't found in
634 C<$ENV{PATH}>, the executable in question was compiled for another
635 architecture, or the #! line in a script points to an interpreter that
636 can't be run for similar reasons. (Or maybe your system doesn't support
641 (F) Perl was trying to execute the indicated program for you because
642 that's what the #! line said. If that's not what you wanted, you may
643 need to mention "perl" on the #! line somewhere.
645 =item Can't execute %s
647 (F) You used the B<-S> switch, but the copies of the script to execute
648 found in the PATH did not have correct permissions.
650 =item Can't find an opnumber for "%s"
652 (F) A string of a form C<CORE::word> was given to prototype(), but there
653 is no builtin with the name C<word>.
655 =item Can't find %s character property "%s"
657 (F) You used C<\p{}> or C<\P{}> but the character property by that name
658 could not be found. Maybe you misspelled the name of the property
659 (remember that the names of character properties consist only of
660 alphanumeric characters), or maybe you forgot the C<Is> or C<In> prefix?
662 =item Can't find label %s
664 (F) You said to goto a label that isn't mentioned anywhere that it's
665 possible for us to go to. See L<perlfunc/goto>.
667 =item Can't find %s on PATH
669 (F) You used the B<-S> switch, but the script to execute could not be
672 =item Can't find %s on PATH, '.' not in PATH
674 (F) You used the B<-S> switch, but the script to execute could not be
675 found in the PATH, or at least not with the correct permissions. The
676 script exists in the current directory, but PATH prohibits running it.
678 =item Can't find string terminator %s anywhere before EOF
680 (F) Perl strings can stretch over multiple lines. This message means
681 that the closing delimiter was omitted. Because bracketed quotes count
682 nesting levels, the following is missing its final parenthesis:
684 print q(The character '(' starts a side comment.);
686 If you're getting this error from a here-document, you may have included
687 unseen whitespace before or after your closing tag. A good programmer's
688 editor will have a way to help you find these characters.
690 =item Can't find %s property definition %s
692 (F) You may have tried to use C<\p> which means a Unicode property for
693 example \p{Lu} is all uppercase letters. if you did mean to use a
694 Unicode property, see L<perlunicode> for the list of known properties.
695 If you didn't mean to use a Unicode property, escape the C<\p>, either
696 C<\\p> (just the C<\p>) or by C<\Q\p> (the rest of the string, until
701 (F) A fatal error occurred while trying to fork while opening a
704 =item Can't get filespec - stale stat buffer?
706 (S) A warning peculiar to VMS. This arises because of the difference
707 between access checks under VMS and under the Unix model Perl assumes.
708 Under VMS, access checks are done by filename, rather than by bits in
709 the stat buffer, so that ACLs and other protections can be taken into
710 account. Unfortunately, Perl assumes that the stat buffer contains all
711 the necessary information, and passes it, instead of the filespec, to
712 the access checking routine. It will try to retrieve the filespec using
713 the device name and FID present in the stat buffer, but this works only
714 if you haven't made a subsequent call to the CRTL stat() routine,
715 because the device name is overwritten with each call. If this warning
716 appears, the name lookup failed, and the access checking routine gave up
717 and returned FALSE, just to be conservative. (Note: The access checking
718 routine knows about the Perl C<stat> operator and file tests, so you
719 shouldn't ever see this warning in response to a Perl command; it arises
720 only if some internal code takes stat buffers lightly.)
722 =item Can't get pipe mailbox device name
724 (P) An error peculiar to VMS. After creating a mailbox to act as a
725 pipe, Perl can't retrieve its name for later use.
727 =item Can't get SYSGEN parameter value for MAXBUF
729 (P) An error peculiar to VMS. Perl asked $GETSYI how big you want your
730 mailbox buffers to be, and didn't get an answer.
732 =item Can't "goto" into the middle of a foreach loop
734 (F) A "goto" statement was executed to jump into the middle of a foreach
735 loop. You can't get there from here. See L<perlfunc/goto>.
737 =item Can't "goto" out of a pseudo block
739 (F) A "goto" statement was executed to jump out of what might look like
740 a block, except that it isn't a proper block. This usually occurs if
741 you tried to jump out of a sort() block or subroutine, which is a no-no.
742 See L<perlfunc/goto>.
744 =item Can't goto subroutine from an eval-string
746 (F) The "goto subroutine" call can't be used to jump out of an eval
747 "string". (You can use it to jump out of an eval {BLOCK}, but you
748 probably don't want to.)
750 =item Can't goto subroutine outside a subroutine
752 (F) The deeply magical "goto subroutine" call can only replace one
753 subroutine call for another. It can't manufacture one out of whole
754 cloth. In general you should be calling it out of only an AUTOLOAD
755 routine anyway. See L<perlfunc/goto>.
757 =item Can't ignore signal CHLD, forcing to default
759 (W signal) Perl has detected that it is being run with the SIGCHLD
760 signal (sometimes known as SIGCLD) disabled. Since disabling this
761 signal will interfere with proper determination of exit status of child
762 processes, Perl has reset the signal to its default value. This
763 situation typically indicates that the parent program under which Perl
764 may be running (e.g. cron) is being very careless.
766 =item Can't "last" outside a loop block
768 (F) A "last" statement was executed to break out of the current block,
769 except that there's this itty bitty problem called there isn't a current
770 block. Note that an "if" or "else" block doesn't count as a "loopish"
771 block, as doesn't a block given to sort(), map() or grep(). You can
772 usually double the curlies to get the same effect though, because the
773 inner curlies will be considered a block that loops once. See
776 =item Can't localize lexical variable %s
778 (F) You used local on a variable name that was previously declared as a
779 lexical variable using "my". This is not allowed. If you want to
780 localize a package variable of the same name, qualify it with the
783 =item Can't localize pseudo-hash element
785 (F) You said something like C<< local $ar->{'key'} >>, where $ar is a
786 reference to a pseudo-hash. That hasn't been implemented yet, but you
787 can get a similar effect by localizing the corresponding array element
788 directly -- C<< local $ar->[$ar->[0]{'key'}] >>.
790 =item Can't localize through a reference
792 (F) You said something like C<local $$ref>, which Perl can't currently
793 handle, because when it goes to restore the old value of whatever $ref
794 pointed to after the scope of the local() is finished, it can't be sure
795 that $ref will still be a reference.
797 =item Can't locate %s
799 (F) You said to C<do> (or C<require>, or C<use>) a file that couldn't be
800 found. Perl looks for the file in all the locations mentioned in @INC,
801 unless the file name included the full path to the file. Perhaps you
802 need to set the PERL5LIB or PERL5OPT environment variable to say where
803 the extra library is, or maybe the script needs to add the library name
804 to @INC. Or maybe you just misspelled the name of the file. See
805 L<perlfunc/require> and L<lib>.
807 =item Can't locate auto/%s.al in @INC
809 (F) A function (or method) was called in a package which allows
810 autoload, but there is no function to autoload. Most probable causes
811 are a misprint in a function/method name or a failure to C<AutoSplit>
812 the file, say, by doing C<make install>.
814 =item Can't locate object method "%s" via package "%s"
816 (F) You called a method correctly, and it correctly indicated a package
817 functioning as a class, but that package doesn't define that particular
818 method, nor does any of its base classes. See L<perlobj>.
820 =item (perhaps you forgot to load "%s"?)
822 (F) This is an educated guess made in conjunction with the message
823 "Can't locate object method \"%s\" via package \"%s\"". It often means
824 that a method requires a package that has not been loaded.
826 =item Can't locate package %s for @%s::ISA
828 (W syntax) The @ISA array contained the name of another package that
829 doesn't seem to exist.
831 =item Can't make list assignment to \%ENV on this system
833 (F) List assignment to %ENV is not supported on some systems, notably
836 =item Can't modify %s in %s
838 (F) You aren't allowed to assign to the item indicated, or otherwise try
839 to change it, such as with an auto-increment.
841 =item Can't modify nonexistent substring
843 (P) The internal routine that does assignment to a substr() was handed
846 =item Can't modify non-lvalue subroutine call
848 (F) Subroutines meant to be used in lvalue context should be declared as
849 such, see L<perlsub/"Lvalue subroutines">.
851 =item Can't msgrcv to read-only var
853 (F) The target of a msgrcv must be modifiable to be used as a receive
856 =item Can't "next" outside a loop block
858 (F) A "next" statement was executed to reiterate the current block, but
859 there isn't a current block. Note that an "if" or "else" block doesn't
860 count as a "loopish" block, as doesn't a block given to sort(), map() or
861 grep(). You can usually double the curlies to get the same effect
862 though, because the inner curlies will be considered a block that loops
863 once. See L<perlfunc/next>.
865 =item Can't open %s: %s
867 (S inplace) The implicit opening of a file through use of the C<< <> >>
868 filehandle, either implicitly under the C<-n> or C<-p> command-line
869 switches, or explicitly, failed for the indicated reason. Usually this
870 is because you don't have read permission for a file which you named on
873 =item Can't open a reference
875 (W io) You tried to open a scalar reference for reading or writing,
876 using the 3-arg open() syntax :
880 but your version of perl is compiled without perlio, and this form of
881 open is not supported.
883 =item Can't open bidirectional pipe
885 (W pipe) You tried to say C<open(CMD, "|cmd|")>, which is not supported.
886 You can try any of several modules in the Perl library to do this, such
887 as IPC::Open2. Alternately, direct the pipe's output to a file using
888 ">", and then read it in under a different file handle.
890 =item Can't open error file %s as stderr
892 (F) An error peculiar to VMS. Perl does its own command line
893 redirection, and couldn't open the file specified after '2>' or '2>>' on
894 the command line for writing.
896 =item Can't open input file %s as stdin
898 (F) An error peculiar to VMS. Perl does its own command line
899 redirection, and couldn't open the file specified after '<' on the
900 command line for reading.
902 =item Can't open output file %s as stdout
904 (F) An error peculiar to VMS. Perl does its own command line
905 redirection, and couldn't open the file specified after '>' or '>>' on
906 the command line for writing.
908 =item Can't open output pipe (name: %s)
910 (P) An error peculiar to VMS. Perl does its own command line
911 redirection, and couldn't open the pipe into which to send data destined
914 =item Can't open perl script%s: %s
916 (F) The script you specified can't be opened for the indicated reason.
918 =item Can't read CRTL environ
920 (S) A warning peculiar to VMS. Perl tried to read an element of %ENV
921 from the CRTL's internal environment array and discovered the array was
922 missing. You need to figure out where your CRTL misplaced its environ
923 or define F<PERL_ENV_TABLES> (see L<perlvms>) so that environ is not
926 =item Can't redefine active sort subroutine %s
928 (F) Perl optimizes the internal handling of sort subroutines and keeps
929 pointers into them. You tried to redefine one such sort subroutine when
930 it was currently active, which is not allowed. If you really want to do
931 this, you should write C<sort { &func } @x> instead of C<sort func @x>.
933 =item Can't "redo" outside a loop block
935 (F) A "redo" statement was executed to restart the current block, but
936 there isn't a current block. Note that an "if" or "else" block doesn't
937 count as a "loopish" block, as doesn't a block given to sort(), map()
938 or grep(). You can usually double the curlies to get the same effect
939 though, because the inner curlies will be considered a block that
940 loops once. See L<perlfunc/redo>.
942 =item Can't remove %s: %s, skipping file
944 (S inplace) You requested an inplace edit without creating a backup
945 file. Perl was unable to remove the original file to replace it with
946 the modified file. The file was left unmodified.
948 =item Can't rename %s to %s: %s, skipping file
950 (S inplace) The rename done by the B<-i> switch failed for some reason,
951 probably because you don't have write permission to the directory.
953 =item Can't reopen input pipe (name: %s) in binary mode
955 (P) An error peculiar to VMS. Perl thought stdin was a pipe, and tried
956 to reopen it to accept binary data. Alas, it failed.
958 =item Can't resolve method `%s' overloading `%s' in package `%s'
960 (F|P) Error resolving overloading specified by a method name (as opposed
961 to a subroutine reference): no such method callable via the package. If
962 method name is C<???>, this is an internal error.
964 =item Can't reswap uid and euid
966 (P) The setreuid() call failed for some reason in the setuid emulator of
969 =item Can't return %s from lvalue subroutine
971 (F) Perl detected an attempt to return illegal lvalues (such as
972 temporary or readonly values) from a subroutine used as an lvalue. This
975 =item Can't return %s to lvalue scalar context
977 (F) You tried to return a complete array or hash from an lvalue subroutine,
978 but you called the subroutine in a way that made Perl think you meant
979 to return only one value. You probably meant to write parentheses around
980 the call to the subroutine, which tell Perl that the call should be in
983 =item Can't return outside a subroutine
985 (F) The return statement was executed in mainline code, that is, where
986 there was no subroutine call to return out of. See L<perlsub>.
988 =item Can't stat script "%s"
990 (P) For some reason you can't fstat() the script even though you have it
991 open already. Bizarre.
993 =item Can't swap uid and euid
995 (P) The setreuid() call failed for some reason in the setuid emulator of
998 =item Can't take log of %g
1000 (F) For ordinary real numbers, you can't take the logarithm of a
1001 negative number or zero. There's a Math::Complex package that comes
1002 standard with Perl, though, if you really want to do that for the
1005 =item Can't take sqrt of %g
1007 (F) For ordinary real numbers, you can't take the square root of a
1008 negative number. There's a Math::Complex package that comes standard
1009 with Perl, though, if you really want to do that.
1011 =item Can't undef active subroutine
1013 (F) You can't undefine a routine that's currently running. You can,
1014 however, redefine it while it's running, and you can even undef the
1015 redefined subroutine while the old routine is running. Go figure.
1019 (F) You tried to unshift an "unreal" array that can't be unshifted, such
1020 as the main Perl stack.
1022 =item Can't upgrade that kind of scalar
1024 (P) The internal sv_upgrade routine adds "members" to an SV, making it
1025 into a more specialized kind of SV. The top several SV types are so
1026 specialized, however, that they cannot be interconverted. This message
1027 indicates that such a conversion was attempted.
1029 =item Can't upgrade to undef
1031 (P) The undefined SV is the bottom of the totem pole, in the scheme of
1032 upgradability. Upgrading to undef indicates an error in the code
1035 =item Can't use an undefined value as %s reference
1037 (F) A value used as either a hard reference or a symbolic reference must
1038 be a defined value. This helps to delurk some insidious errors.
1040 =item Can't use anonymous symbol table for method lookup
1042 (P) The internal routine that does method lookup was handed a symbol
1043 table that doesn't have a name. Symbol tables can become anonymous
1044 for example by undefining stashes: C<undef %Some::Package::>.
1046 =item Can't use bareword ("%s") as %s ref while "strict refs" in use
1048 (F) Only hard references are allowed by "strict refs". Symbolic
1049 references are disallowed. See L<perlref>.
1051 =item Can't use %! because Errno.pm is not available
1053 (F) The first time the %! hash is used, perl automatically loads the
1054 Errno.pm module. The Errno module is expected to tie the %! hash to
1055 provide symbolic names for C<$!> errno values.
1057 =item Can't use %s for loop variable
1059 (F) Only a simple scalar variable may be used as a loop variable on a
1062 =item Can't use global %s in "my"
1064 (F) You tried to declare a magical variable as a lexical variable. This
1065 is not allowed, because the magic can be tied to only one location
1066 (namely the global variable) and it would be incredibly confusing to
1067 have variables in your program that looked like magical variables but
1070 =item Can't use "my %s" in sort comparison
1072 (F) The global variables $a and $b are reserved for sort comparisons.
1073 You mentioned $a or $b in the same line as the <=> or cmp operator,
1074 and the variable had earlier been declared as a lexical variable.
1075 Either qualify the sort variable with the package name, or rename the
1078 =item Can't use %s ref as %s ref
1080 (F) You've mixed up your reference types. You have to dereference a
1081 reference of the type needed. You can use the ref() function to
1082 test the type of the reference, if need be.
1084 =item Can't use string ("%s") as %s ref while "strict refs" in use
1086 (F) Only hard references are allowed by "strict refs". Symbolic
1087 references are disallowed. See L<perlref>.
1089 =item Can't use subscript on %s
1091 (F) The compiler tried to interpret a bracketed expression as a
1092 subscript. But to the left of the brackets was an expression that
1093 didn't look like an array reference, or anything else subscriptable.
1095 =item Can't use \%c to mean $%c in expression
1097 (W syntax) In an ordinary expression, backslash is a unary operator that
1098 creates a reference to its argument. The use of backslash to indicate a
1099 backreference to a matched substring is valid only as part of a regular
1100 expression pattern. Trying to do this in ordinary Perl code produces a
1101 value that prints out looking like SCALAR(0xdecaf). Use the $1 form
1104 =item Can't weaken a nonreference
1106 (F) You attempted to weaken something that was not a reference. Only
1107 references can be weakened.
1109 =item Can't x= to read-only value
1111 (F) You tried to repeat a constant value (often the undefined value)
1112 with an assignment operator, which implies modifying the value itself.
1113 Perhaps you need to copy the value to a temporary, and repeat that.
1115 =item Character in "C" format wrapped
1121 where $x is either less than 0 or more than 255; the C<"C"> format is
1122 only for encoding native operating system characters (ASCII, EBCDIC,
1123 and so on) and not for Unicode characters, so Perl behaved as if you meant
1127 If you actually want to pack Unicode codepoints, use the C<"U"> format
1130 =item Character in "c" format wrapped
1136 where $x is either less than -128 or more than 127; the C<"c"> format
1137 is only for encoding native operating system characters (ASCII, EBCDIC,
1138 and so on) and not for Unicode characters, so Perl behaved as if you meant
1140 pack("c", $x & 255);
1142 If you actually want to pack Unicode codepoints, use the C<"U"> format
1145 =item close() on unopened filehandle %s
1147 (W unopened) You tried to close a filehandle that was never opened.
1149 =item %s: Command not found
1151 (A) You've accidentally run your script through B<csh> instead of Perl.
1152 Check the #! line, or manually feed your script into Perl yourself.
1154 =item Compilation failed in require
1156 (F) Perl could not compile a file specified in a C<require> statement.
1157 Perl uses this generic message when none of the errors that it
1158 encountered were severe enough to halt compilation immediately.
1160 =item Complex regular subexpression recursion limit (%d) exceeded
1162 (W regexp) The regular expression engine uses recursion in complex
1163 situations where back-tracking is required. Recursion depth is limited
1164 to 32766, or perhaps less in architectures where the stack cannot grow
1165 arbitrarily. ("Simple" and "medium" situations are handled without
1166 recursion and are not subject to a limit.) Try shortening the string
1167 under examination; looping in Perl code (e.g. with C<while>) rather than
1168 in the regular expression engine; or rewriting the regular expression so
1169 that it is simpler or backtracks less. (See L<perlfaq2> for information
1170 on I<Mastering Regular Expressions>.)
1172 =item cond_broadcast() called on unlocked variable
1174 (W threads) Within a thread-enabled program, you tried to call
1175 cond_broadcast() on a variable which wasn't locked. The cond_broadcast()
1176 function is used to wake up another thread that is waiting in a
1177 cond_wait(). To ensure that the signal isn't sent before the other thread
1178 has a chance to enter the wait, it is usual for the signaling thread to
1179 first wait for a lock on variable. This lock attempt will only succeed
1180 after the other thread has entered cond_wait() and thus relinquished the
1184 =item cond_signal() called on unlocked variable
1186 (W threads) Within a thread-enabled program, you tried to call
1187 cond_signal() on a variable which wasn't locked. The cond_signal()
1188 function is used to wake up another thread that is waiting in a
1189 cond_wait(). To ensure that the signal isn't sent before the other thread
1190 has a chance to enter the wait, it is usual for the signaling thread to
1191 first wait for a lock on variable. This lock attempt will only succeed
1192 after the other thread has entered cond_wait() and thus relinquished the
1195 =item connect() on closed socket %s
1197 (W closed) You tried to do a connect on a closed socket. Did you forget
1198 to check the return value of your socket() call? See
1199 L<perlfunc/connect>.
1201 =item Constant(%s)%s: %s
1203 (F) The parser found inconsistencies either while attempting to define
1204 an overloaded constant, or when trying to find the character name
1205 specified in the C<\N{...}> escape. Perhaps you forgot to load the
1206 corresponding C<overload> or C<charnames> pragma? See L<charnames> and
1209 =item Constant is not %s reference
1211 (F) A constant value (perhaps declared using the C<use constant> pragma)
1212 is being dereferenced, but it amounts to the wrong type of reference.
1213 The message indicates the type of reference that was expected. This
1214 usually indicates a syntax error in dereferencing the constant value.
1215 See L<perlsub/"Constant Functions"> and L<constant>.
1217 =item Constant subroutine %s redefined
1219 (S|W redefine) You redefined a subroutine which had previously been
1220 eligible for inlining. See L<perlsub/"Constant Functions"> for
1221 commentary and workarounds.
1223 =item Constant subroutine %s undefined
1225 (W misc) You undefined a subroutine which had previously been eligible
1226 for inlining. See L<perlsub/"Constant Functions"> for commentary and
1229 =item Copy method did not return a reference
1231 (F) The method which overloads "=" is buggy. See
1232 L<overload/Copy Constructor>.
1234 =item CORE::%s is not a keyword
1236 (F) The CORE:: namespace is reserved for Perl keywords.
1238 =item corrupted regexp pointers
1240 (P) The regular expression engine got confused by what the regular
1241 expression compiler gave it.
1243 =item corrupted regexp program
1245 (P) The regular expression engine got passed a regexp program without a
1248 =item Corrupt malloc ptr 0x%lx at 0x%lx
1250 (P) The malloc package that comes with Perl had an internal failure.
1252 =item C<-p> destination: %s
1254 (F) An error occurred during the implicit output invoked by the C<-p>
1255 command-line switch. (This output goes to STDOUT unless you've
1256 redirected it with select().)
1258 =item C<-T> and C<-B> not implemented on filehandles
1260 (F) Perl can't peek at the stdio buffer of filehandles when it doesn't
1261 know about your kind of stdio. You'll have to use a filename instead.
1263 =item Deep recursion on subroutine "%s"
1265 (W recursion) This subroutine has called itself (directly or indirectly)
1266 100 times more than it has returned. This probably indicates an
1267 infinite recursion, unless you're writing strange benchmark programs, in
1268 which case it indicates something else.
1270 =item defined(@array) is deprecated
1272 (D deprecated) defined() is not usually useful on arrays because it
1273 checks for an undefined I<scalar> value. If you want to see if the
1274 array is empty, just use C<if (@array) { # not empty }> for example.
1276 =item defined(%hash) is deprecated
1278 (D deprecated) defined() is not usually useful on hashes because it
1279 checks for an undefined I<scalar> value. If you want to see if the hash
1280 is empty, just use C<if (%hash) { # not empty }> for example.
1282 =item %s defines neither package nor VERSION--version check failed
1284 (F) You said something like "use Module 42" but in the Module file
1285 there are neither package declarations nor a C<$VERSION>.
1287 =item Delimiter for here document is too long
1289 (F) In a here document construct like C<<<FOO>, the label C<FOO> is too
1290 long for Perl to handle. You have to be seriously twisted to write code
1291 that triggers this error.
1293 =item Did not produce a valid header
1297 =item %s did not return a true value
1299 (F) A required (or used) file must return a true value to indicate that
1300 it compiled correctly and ran its initialization code correctly. It's
1301 traditional to end such a file with a "1;", though any true value would
1302 do. See L<perlfunc/require>.
1304 =item (Did you mean &%s instead?)
1306 (W) You probably referred to an imported subroutine &FOO as $FOO or some
1309 =item (Did you mean "local" instead of "our"?)
1311 (W misc) Remember that "our" does not localize the declared global
1312 variable. You have declared it again in the same lexical scope, which
1315 =item (Did you mean $ or @ instead of %?)
1317 (W) You probably said %hash{$key} when you meant $hash{$key} or
1318 @hash{@keys}. On the other hand, maybe you just meant %hash and got
1323 (F) You passed die() an empty string (the equivalent of C<die "">) or
1324 you called it with no args and both C<$@> and C<$_> were empty.
1326 =item Document contains no data
1330 =item %s does not define %s::VERSION--version check failed
1332 (F) You said something like "use Module 42" but the Module did not
1333 define a C<$VERSION.>
1335 =item Don't know how to handle magic of type '%s'
1337 (P) The internal handling of magical variables has been cursed.
1339 =item do_study: out of memory
1341 (P) This should have been caught by safemalloc() instead.
1343 =item (Do you need to predeclare %s?)
1345 (S) This is an educated guess made in conjunction with the message "%s
1346 found where operator expected". It often means a subroutine or module
1347 name is being referenced that hasn't been declared yet. This may be
1348 because of ordering problems in your file, or because of a missing
1349 "sub", "package", "require", or "use" statement. If you're referencing
1350 something that isn't defined yet, you don't actually have to define the
1351 subroutine or package before the current location. You can use an empty
1352 "sub foo;" or "package FOO;" to enter a "forward" declaration.
1354 =item dump() better written as CORE::dump()
1356 (W misc) You used the obsolescent C<dump()> built-in function, without fully
1357 qualifying it as C<CORE::dump()>. Maybe it's a typo. See L<perlfunc/dump>.
1359 =item Duplicate free() ignored
1361 (S malloc) An internal routine called free() on something that had
1364 =item elseif should be elsif
1366 (S) There is no keyword "elseif" in Perl because Larry thinks it's ugly.
1367 Your code will be interpreted as an attempt to call a method named
1368 "elseif" for the class returned by the following block. This is
1369 unlikely to be what you want.
1373 (F) C<\p> and C<\P> are used to introduce a named Unicode property, as
1374 described in L<perlunicode> and L<perlre>. You used C<\p> or C<\P> in
1375 a regular expression without specifying the property name.
1377 =item entering effective %s failed
1379 (F) While under the C<use filetest> pragma, switching the real and
1380 effective uids or gids failed.
1382 =item Error converting file specification %s
1384 (F) An error peculiar to VMS. Because Perl may have to deal with file
1385 specifications in either VMS or Unix syntax, it converts them to a
1386 single form when it must operate on them directly. Either you've passed
1387 an invalid file specification to Perl, or you've found a case the
1388 conversion routines don't handle. Drat.
1390 =item %s: Eval-group in insecure regular expression
1392 (F) Perl detected tainted data when trying to compile a regular
1393 expression that contains the C<(?{ ... })> zero-width assertion, which
1394 is unsafe. See L<perlre/(?{ code })>, and L<perlsec>.
1396 =item %s: Eval-group not allowed at run time
1398 (F) Perl tried to compile a regular expression containing the
1399 C<(?{ ... })> zero-width assertion at run time, as it would when the
1400 pattern contains interpolated values. Since that is a security risk, it
1401 is not allowed. If you insist, you may still do this by explicitly
1402 building the pattern from an interpolated string at run time and using
1403 that in an eval(). See L<perlre/(?{ code })>.
1405 =item %s: Eval-group not allowed, use re 'eval'
1407 (F) A regular expression contained the C<(?{ ... })> zero-width
1408 assertion, but that construct is only allowed when the C<use re 'eval'>
1409 pragma is in effect. See L<perlre/(?{ code })>.
1411 =item Excessively long <> operator
1413 (F) The contents of a <> operator may not exceed the maximum size of a
1414 Perl identifier. If you're just trying to glob a long list of
1415 filenames, try using the glob() operator, or put the filenames into a
1416 variable and glob that.
1418 =item exec? I'm not *that* kind of operating system
1420 (F) The C<exec> function is not implemented in MacPerl. See L<perlport>.
1422 =item Execution of %s aborted due to compilation errors
1424 (F) The final summary message when a Perl compilation fails.
1426 =item Exiting eval via %s
1428 (W exiting) You are exiting an eval by unconventional means, such as a
1429 goto, or a loop control statement.
1431 =item Exiting format via %s
1433 (W exiting) You are exiting an eval by unconventional means, such as a
1434 goto, or a loop control statement.
1436 =item Exiting pseudo-block via %s
1438 (W exiting) You are exiting a rather special block construct (like a
1439 sort block or subroutine) by unconventional means, such as a goto, or a
1440 loop control statement. See L<perlfunc/sort>.
1442 =item Exiting subroutine via %s
1444 (W exiting) You are exiting a subroutine by unconventional means, such
1445 as a goto, or a loop control statement.
1447 =item Exiting substitution via %s
1449 (W exiting) You are exiting a substitution by unconventional means, such
1450 as a return, a goto, or a loop control statement.
1452 =item Explicit blessing to '' (assuming package main)
1454 (W misc) You are blessing a reference to a zero length string. This has
1455 the effect of blessing the reference into the package main. This is
1456 usually not what you want. Consider providing a default target package,
1457 e.g. bless($ref, $p || 'MyPackage');
1459 =item %s: Expression syntax
1461 (A) You've accidentally run your script through B<csh> instead of Perl.
1462 Check the #! line, or manually feed your script into Perl yourself.
1464 =item %s failed--call queue aborted
1466 (F) An untrapped exception was raised while executing a CHECK, INIT, or
1467 END subroutine. Processing of the remainder of the queue of such
1468 routines has been prematurely ended.
1470 =item False [] range "%s" in regex; marked by <-- HERE in m/%s/
1472 (W regexp) A character class range must start and end at a literal
1473 character, not another character class like C<\d> or C<[:alpha:]>. The "-"
1474 in your false range is interpreted as a literal "-". Consider quoting the
1475 "-", "\-". The <-- HERE shows in the regular expression about where the
1476 problem was discovered. See L<perlre>.
1478 =item Fatal VMS error at %s, line %d
1480 (P) An error peculiar to VMS. Something untoward happened in a VMS
1481 system service or RTL routine; Perl's exit status should provide more
1482 details. The filename in "at %s" and the line number in "line %d" tell
1483 you which section of the Perl source code is distressed.
1485 =item fcntl is not implemented
1487 (F) Your machine apparently doesn't implement fcntl(). What is this, a
1488 PDP-11 or something?
1490 =item Filehandle %s opened only for input
1492 (W io) You tried to write on a read-only filehandle. If you intended it
1493 to be a read-write filehandle, you needed to open it with "+<" or "+>"
1494 or "+>>" instead of with "<" or nothing. If you intended only to write
1495 the file, use ">" or ">>". See L<perlfunc/open>.
1497 =item Filehandle %s opened only for output
1499 (W io) You tried to read from a filehandle opened only for writing. If
1500 you intended it to be a read/write filehandle, you needed to open it
1501 with "+<" or "+>" or "+>>" instead of with "<" or nothing. If you
1502 intended only to read from the file, use "<". See L<perlfunc/open>.
1504 =item Final $ should be \$ or $name
1506 (F) You must now decide whether the final $ in a string was meant to be
1507 a literal dollar sign, or was meant to introduce a variable name that
1508 happens to be missing. So you have to put either the backslash or the
1511 =item Final @ should be \@ or @name
1513 (F) You must now decide whether the final @ in a string was meant to be
1514 a literal "at" sign, or was meant to introduce a variable name that
1515 happens to be missing. So you have to put either the backslash or the
1518 =item flock() on closed filehandle %s
1520 (W closed) The filehandle you're attempting to flock() got itself closed
1521 some time before now. Check your control flow. flock() operates on
1522 filehandles. Are you attempting to call flock() on a dirhandle by the
1525 =item Quantifier follows nothing in regex;
1527 marked by <-- HERE in m/%s/
1529 (F) You started a regular expression with a quantifier. Backslash it if you
1530 meant it literally. The <-- HERE shows in the regular expression about
1531 where the problem was discovered. See L<perlre>.
1533 =item Format not terminated
1535 (F) A format must be terminated by a line with a solitary dot. Perl got
1536 to the end of your file without finding such a line.
1538 =item Format %s redefined
1540 (W redefine) You redefined a format. To suppress this warning, say
1543 no warnings 'redefine';
1544 eval "format NAME =...";
1547 =item Found = in conditional, should be ==
1557 (or something like that).
1559 =item %s found where operator expected
1561 (S) The Perl lexer knows whether to expect a term or an operator. If it
1562 sees what it knows to be a term when it was expecting to see an
1563 operator, it gives you this warning. Usually it indicates that an
1564 operator or delimiter was omitted, such as a semicolon.
1566 =item gdbm store returned %d, errno %d, key "%s"
1568 (S) A warning from the GDBM_File extension that a store failed.
1570 =item gethostent not implemented
1572 (F) Your C library apparently doesn't implement gethostent(), probably
1573 because if it did, it'd feel morally obligated to return every hostname
1576 =item get%sname() on closed socket %s
1578 (W closed) You tried to get a socket or peer socket name on a closed
1579 socket. Did you forget to check the return value of your socket() call?
1581 =item getpwnam returned invalid UIC %#o for user "%s"
1583 (S) A warning peculiar to VMS. The call to C<sys$getuai> underlying the
1584 C<getpwnam> operator returned an invalid UIC.
1586 =item getsockopt() on closed socket %s
1588 (W closed) You tried to get a socket option on a closed socket. Did you
1589 forget to check the return value of your socket() call? See
1590 L<perlfunc/getsockopt>.
1592 =item Global symbol "%s" requires explicit package name
1594 (F) You've said "use strict vars", which indicates that all variables
1595 must either be lexically scoped (using "my"), declared beforehand using
1596 "our", or explicitly qualified to say which package the global variable
1599 =item glob failed (%s)
1601 (W glob) Something went wrong with the external program(s) used for
1602 C<glob> and C<< <*.c> >>. Usually, this means that you supplied a
1603 C<glob> pattern that caused the external program to fail and exit with a
1604 nonzero status. If the message indicates that the abnormal exit
1605 resulted in a coredump, this may also mean that your csh (C shell) is
1606 broken. If so, you should change all of the csh-related variables in
1607 config.sh: If you have tcsh, make the variables refer to it as if it
1608 were csh (e.g. C<full_csh='/usr/bin/tcsh'>); otherwise, make them all
1609 empty (except that C<d_csh> should be C<'undef'>) so that Perl will
1610 think csh is missing. In either case, after editing config.sh, run
1611 C<./Configure -S> and rebuild Perl.
1613 =item Glob not terminated
1615 (F) The lexer saw a left angle bracket in a place where it was expecting
1616 a term, so it's looking for the corresponding right angle bracket, and
1617 not finding it. Chances are you left some needed parentheses out
1618 earlier in the line, and you really meant a "less than".
1620 =item Got an error from DosAllocMem
1622 (P) An error peculiar to OS/2. Most probably you're using an obsolete
1623 version of Perl, and this should not happen anyway.
1625 =item goto must have label
1627 (F) Unlike with "next" or "last", you're not allowed to goto an
1628 unspecified destination. See L<perlfunc/goto>.
1630 =item %s-group starts with a count
1632 (F) In pack/unpack a ()-group started with a count. A count is
1633 supposed to follow something: a template character or a ()-group.
1635 =item %s had compilation errors
1637 (F) The final summary message when a C<perl -c> fails.
1639 =item Had to create %s unexpectedly
1641 (S internal) A routine asked for a symbol from a symbol table that ought
1642 to have existed already, but for some reason it didn't, and had to be
1643 created on an emergency basis to prevent a core dump.
1645 =item Hash %%s missing the % in argument %d of %s()
1647 (D deprecated) Really old Perl let you omit the % on hash names in some
1648 spots. This is now heavily deprecated.
1650 =item %s has too many errors
1652 (F) The parser has given up trying to parse the program after 10 errors.
1653 Further error messages would likely be uninformative.
1655 =item Hexadecimal number > 0xffffffff non-portable
1657 (W portable) The hexadecimal number you specified is larger than 2**32-1
1658 (4294967295) and therefore non-portable between systems. See
1659 L<perlport> for more on portability concerns.
1661 =item Identifier too long
1663 (F) Perl limits identifiers (names for variables, functions, etc.) to
1664 about 250 characters for simple names, and somewhat more for compound
1665 names (like C<$A::B>). You've exceeded Perl's limits. Future versions
1666 of Perl are likely to eliminate these arbitrary limitations.
1668 =item Illegal binary digit %s
1670 (F) You used a digit other than 0 or 1 in a binary number.
1672 =item Illegal binary digit %s ignored
1674 (W digit) You may have tried to use a digit other than 0 or 1 in a
1675 binary number. Interpretation of the binary number stopped before the
1678 =item Illegal character %s (carriage return)
1680 (F) Perl normally treats carriage returns in the program text as it
1681 would any other whitespace, which means you should never see this error
1682 when Perl was built using standard options. For some reason, your
1683 version of Perl appears to have been built without this support. Talk
1684 to your Perl administrator.
1686 =item Illegal character in prototype for %s : %s
1688 (W syntax) An illegal character was found in a prototype declaration. Legal
1689 characters in prototypes are $, @, %, *, ;, [, ], &, and \.
1691 =item Illegal division by zero
1693 (F) You tried to divide a number by 0. Either something was wrong in
1694 your logic, or you need to put a conditional in to guard against
1697 =item Illegal hexadecimal digit %s ignored
1699 (W digit) You may have tried to use a character other than 0 - 9 or
1700 A - F, a - f in a hexadecimal number. Interpretation of the hexadecimal
1701 number stopped before the illegal character.
1703 =item Illegal modulus zero
1705 (F) You tried to divide a number by 0 to get the remainder. Most
1706 numbers don't take to this kindly.
1708 =item Illegal number of bits in vec
1710 (F) The number of bits in vec() (the third argument) must be a power of
1711 two from 1 to 32 (or 64, if your platform supports that).
1713 =item Illegal octal digit %s
1715 (F) You used an 8 or 9 in an octal number.
1717 =item Illegal octal digit %s ignored
1719 (W digit) You may have tried to use an 8 or 9 in an octal number.
1720 Interpretation of the octal number stopped before the 8 or 9.
1722 =item Illegal switch in PERL5OPT: %s
1724 (X) The PERL5OPT environment variable may only be used to set the
1725 following switches: B<-[DIMUdmtw]>.
1727 =item Ill-formed CRTL environ value "%s"
1729 (W internal) A warning peculiar to VMS. Perl tried to read the CRTL's
1730 internal environ array, and encountered an element without the C<=>
1731 delimiter used to separate keys from values. The element is ignored.
1733 =item Ill-formed message in prime_env_iter: |%s|
1735 (W internal) A warning peculiar to VMS. Perl tried to read a logical
1736 name or CLI symbol definition when preparing to iterate over %ENV, and
1737 didn't see the expected delimiter between key and value, so the line was
1740 =item (in cleanup) %s
1742 (W misc) This prefix usually indicates that a DESTROY() method raised
1743 the indicated exception. Since destructors are usually called by the
1744 system at arbitrary points during execution, and often a vast number of
1745 times, the warning is issued only once for any number of failures that
1746 would otherwise result in the same message being repeated.
1748 Failure of user callbacks dispatched using the C<G_KEEPERR> flag could
1749 also result in this warning. See L<perlcall/G_KEEPERR>.
1751 =item In EBCDIC the v-string components cannot exceed 2147483647
1753 (F) An error peculiar to EBCDIC. Internally, v-strings are stored as
1754 Unicode code points, and encoded in EBCDIC as UTF-EBCDIC. The UTF-EBCDIC
1755 encoding is limited to code points no larger than 2147483647 (0x7FFFFFFF).
1757 =item Insecure dependency in %s
1759 (F) You tried to do something that the tainting mechanism didn't like.
1760 The tainting mechanism is turned on when you're running setuid or
1761 setgid, or when you specify B<-T> to turn it on explicitly. The
1762 tainting mechanism labels all data that's derived directly or indirectly
1763 from the user, who is considered to be unworthy of your trust. If any
1764 such data is used in a "dangerous" operation, you get this error. See
1765 L<perlsec> for more information.
1767 =item Insecure directory in %s
1769 (F) You can't use system(), exec(), or a piped open in a setuid or
1770 setgid script if C<$ENV{PATH}> contains a directory that is writable by
1771 the world. See L<perlsec>.
1773 =item Insecure $ENV{%s} while running %s
1775 (F) You can't use system(), exec(), or a piped open in a setuid or
1776 setgid script if any of C<$ENV{PATH}>, C<$ENV{IFS}>, C<$ENV{CDPATH}>,
1777 C<$ENV{ENV}> or C<$ENV{BASH_ENV}> are derived from data supplied (or
1778 potentially supplied) by the user. The script must set the path to a
1779 known value, using trustworthy data. See L<perlsec>.
1781 =item Integer overflow in %s number
1783 (W overflow) The hexadecimal, octal or binary number you have specified
1784 either as a literal or as an argument to hex() or oct() is too big for
1785 your architecture, and has been converted to a floating point number.
1786 On a 32-bit architecture the largest hexadecimal, octal or binary number
1787 representable without overflow is 0xFFFFFFFF, 037777777777, or
1788 0b11111111111111111111111111111111 respectively. Note that Perl
1789 transparently promotes all numbers to a floating point representation
1790 internally--subject to loss of precision errors in subsequent
1793 =item Internal disaster in regex; marked by <-- HERE in m/%s/
1795 (P) Something went badly wrong in the regular expression parser.
1796 The <-- HERE shows in the regular expression about where the problem was
1799 =item Internal inconsistency in tracking vforks
1801 (S) A warning peculiar to VMS. Perl keeps track of the number of times
1802 you've called C<fork> and C<exec>, to determine whether the current call
1803 to C<exec> should affect the current script or a subprocess (see
1804 L<perlvms/"exec LIST">). Somehow, this count has become scrambled, so
1805 Perl is making a guess and treating this C<exec> as a request to
1806 terminate the Perl script and execute the specified command.
1808 =item Internal urp in regex; marked by <-- HERE in m/%s/
1810 (P) Something went badly awry in the regular expression parser. The
1811 <-- HERE shows in the regular expression about where the problem was
1814 =item %s (...) interpreted as function
1816 (W syntax) You've run afoul of the rule that says that any list operator
1817 followed by parentheses turns into a function, with all the list
1818 operators arguments found inside the parentheses. See
1819 L<perlop/Terms and List Operators (Leftward)>.
1821 =item Invalid %s attribute: %s
1823 The indicated attribute for a subroutine or variable was not recognized
1824 by Perl or by a user-supplied handler. See L<attributes>.
1826 =item Invalid %s attributes: %s
1828 The indicated attributes for a subroutine or variable were not
1829 recognized by Perl or by a user-supplied handler. See L<attributes>.
1831 =item Invalid conversion in %s: "%s"
1833 (W printf) Perl does not understand the given format conversion. See
1834 L<perlfunc/sprintf>.
1836 =item Invalid [] range "%s" in regex; marked by <-- HERE in m/%s/
1838 (F) The range specified in a character class had a minimum character
1839 greater than the maximum character. One possibility is that you forgot the
1840 C<{}> from your ending C<\x{}> - C<\x> without the curly braces can go only
1841 up to C<ff>. The <-- HERE shows in the regular expression about where the
1842 problem was discovered. See L<perlre>.
1844 =item Invalid [] range "%s" in transliteration operator
1846 (F) The range specified in the tr/// or y/// operator had a minimum
1847 character greater than the maximum character. See L<perlop>.
1849 =item Invalid separator character %s in attribute list
1851 (F) Something other than a colon or whitespace was seen between the
1852 elements of an attribute list. If the previous attribute had a
1853 parenthesised parameter list, perhaps that list was terminated too soon.
1856 =item Invalid type in pack: '%s'
1858 (F) The given character is not a valid pack type. See L<perlfunc/pack>.
1859 (W pack) The given character is not a valid pack type but used to be
1862 =item Invalid type in unpack: '%s'
1864 (F) The given character is not a valid unpack type. See
1866 (W unpack) The given character is not a valid unpack type but used to be
1869 =item ioctl is not implemented
1871 (F) Your machine apparently doesn't implement ioctl(), which is pretty
1872 strange for a machine that supports C.
1874 =item ioctl() on unopened %s
1876 (W unopened) You tried ioctl() on a filehandle that was never opened.
1877 Check you control flow and number of arguments.
1879 =item IO::Socket::atmark not implemented on this architecture
1881 (F) Your machine doesn't implement the sockatmark() functionality,
1882 neither as a system call or an ioctl call (SIOCATMARK).
1884 =item `%s' is not a code reference
1886 (W overload) The second (fourth, sixth, ...) argument of overload::constant
1887 needs to be a code reference. Either an anonymous subroutine, or a reference
1890 =item `%s' is not an overloadable type
1892 (W overload) You tried to overload a constant type the overload package is
1895 =item junk on end of regexp
1897 (P) The regular expression parser is confused.
1899 =item Label not found for "last %s"
1901 (F) You named a loop to break out of, but you're not currently in a loop
1902 of that name, not even if you count where you were called from. See
1905 =item Label not found for "next %s"
1907 (F) You named a loop to continue, but you're not currently in a loop of
1908 that name, not even if you count where you were called from. See
1911 =item Label not found for "redo %s"
1913 (F) You named a loop to restart, but you're not currently in a loop of
1914 that name, not even if you count where you were called from. See
1917 =item leaving effective %s failed
1919 (F) While under the C<use filetest> pragma, switching the real and
1920 effective uids or gids failed.
1922 =item listen() on closed socket %s
1924 (W closed) You tried to do a listen on a closed socket. Did you forget
1925 to check the return value of your socket() call? See
1928 =item lstat() on filehandle %s
1930 (W io) You tried to do an lstat on a filehandle. What did you mean
1931 by that? lstat() makes sense only on filenames. (Perl did a fstat()
1932 instead on the filehandle.)
1934 =item Lvalue subs returning %s not implemented yet
1936 (F) Due to limitations in the current implementation, array and hash
1937 values cannot be returned in subroutines used in lvalue context. See
1938 L<perlsub/"Lvalue subroutines">.
1940 =item Lookbehind longer than %d not implemented in regex;
1942 marked by <-- HERE in m/%s/
1944 (F) There is currently a limit on the length of string which lookbehind can
1945 handle. This restriction may be eased in a future release. The <-- HERE
1946 shows in the regular expression about where the problem was discovered.
1948 =item Malformed PERLLIB_PREFIX
1950 (F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form
1957 with nonempty prefix1 and prefix2. If C<prefix1> is indeed a prefix of
1958 a builtin library search path, prefix2 is substituted. The error may
1959 appear if components are not found, or are too long. See
1960 "PERLLIB_PREFIX" in L<perlos2>.
1962 =item Malformed prototype for %s: %s
1964 (F) You tried to use a function with a malformed prototype. The
1965 syntax of function prototypes is given a brief compile-time check for
1966 obvious errors like invalid characters. A more rigorous check is run
1967 when the function is called.
1969 =item Malformed UTF-8 character (%s)
1971 Perl detected something that didn't comply with UTF-8 encoding rules.
1973 One possible cause is that you read in data that you thought to be in
1974 UTF-8 but it wasn't (it was for example legacy 8-bit data). Another
1975 possibility is careless use of utf8::upgrade().
1977 =item Malformed UTF-16 surrogate
1979 Perl thought it was reading UTF-16 encoded character data but while
1980 doing it Perl met a malformed Unicode surrogate.
1982 =item %s matches null string many times in regex;
1984 marked by <-- HERE in m/%s/
1986 (W regexp) The pattern you've specified would be an infinite loop if the
1987 regular expression engine didn't specifically check for that. The <-- HERE
1988 shows in the regular expression about where the problem was discovered.
1991 =item "%s" may clash with future reserved word
1993 (W) This warning may be due to running a perl5 script through a perl4
1994 interpreter, especially if the word that is being warned about is
1997 =item % may only be used in unpack
1999 (F) You can't pack a string by supplying a checksum, because the
2000 checksumming process loses information, and you can't go the other way.
2001 See L<perlfunc/unpack>.
2003 =item Method for operation %s not found in package %s during blessing
2005 (F) An attempt was made to specify an entry in an overloading table that
2006 doesn't resolve to a valid subroutine. See L<overload>.
2008 =item Method %s not permitted
2012 =item Might be a runaway multi-line %s string starting on line %d
2014 (S) An advisory indicating that the previous error may have been caused
2015 by a missing delimiter on a string or pattern, because it eventually
2016 ended earlier on the current line.
2018 =item Misplaced _ in number
2020 (W syntax) An underscore (underbar) in a numeric constant did not
2021 separate two digits.
2023 =item Missing %sbrace%s on \N{}
2025 (F) Wrong syntax of character name literal C<\N{charname}> within
2026 double-quotish context.
2028 =item Missing comma after first argument to %s function
2030 (F) While certain functions allow you to specify a filehandle or an
2031 "indirect object" before the argument list, this ain't one of them.
2033 =item Missing command in piped open
2035 (W pipe) You used the C<open(FH, "| command")> or
2036 C<open(FH, "command |")> construction, but the command was missing or
2039 =item Missing name in "my sub"
2041 (F) The reserved syntax for lexically scoped subroutines requires that
2042 they have a name with which they can be found.
2044 =item Missing $ on loop variable
2046 (F) Apparently you've been programming in B<csh> too much. Variables
2047 are always mentioned with the $ in Perl, unlike in the shells, where it
2048 can vary from one line to the next.
2050 =item (Missing operator before %s?)
2052 (S) This is an educated guess made in conjunction with the message "%s
2053 found where operator expected". Often the missing operator is a comma.
2055 =item Missing right brace on %s
2057 (F) Missing right brace in C<\p{...}> or C<\P{...}>.
2059 =item Missing right curly or square bracket
2061 (F) The lexer counted more opening curly or square brackets than closing
2062 ones. As a general rule, you'll find it's missing near the place you
2065 =item (Missing semicolon on previous line?)
2067 (S) This is an educated guess made in conjunction with the message "%s
2068 found where operator expected". Don't automatically put a semicolon on
2069 the previous line just because you saw this message.
2071 =item Modification of a read-only value attempted
2073 (F) You tried, directly or indirectly, to change the value of a
2074 constant. You didn't, of course, try "2 = 1", because the compiler
2075 catches that. But an easy way to do the same thing is:
2077 sub mod { $_[0] = 1 }
2080 Another way is to assign to a substr() that's off the end of the string.
2082 Yet another way is to assign to a C<foreach> loop I<VAR> when I<VAR>
2083 is aliased to a constant in the look I<LIST>:
2086 foreach my $n ($x, 2) {
2087 $n *= 2; # modifies the $x, but fails on attempt to modify the 2
2090 =item Modification of non-creatable array value attempted, %s
2092 (F) You tried to make an array value spring into existence, and the
2093 subscript was probably negative, even counting from end of the array
2096 =item Modification of non-creatable hash value attempted, %s
2098 (P) You tried to make a hash value spring into existence, and it
2099 couldn't be created for some peculiar reason.
2101 =item Module name must be constant
2103 (F) Only a bare module name is allowed as the first argument to a "use".
2105 =item Module name required with -%c option
2107 (F) The C<-M> or C<-m> options say that Perl should load some module, but
2108 you omitted the name of the module. Consult L<perlrun> for full details
2109 about C<-M> and C<-m>.
2111 =item More than one argument to open
2113 (F) The C<open> function has been asked to open multiple files. This
2114 can happen if you are trying to open a pipe to a command that takes a
2115 list of arguments, but have forgotten to specify a piped open mode.
2116 See L<perlfunc/open> for details.
2118 =item msg%s not implemented
2120 (F) You don't have System V message IPC on your system.
2122 =item Multidimensional syntax %s not supported
2124 (W syntax) Multidimensional arrays aren't written like C<$foo[1,2,3]>.
2125 They're written like C<$foo[1][2][3]>, as in C.
2127 =item / must be followed by a*, A* or Z*
2129 (F) You had a pack template indicating a counted-length string,
2130 Currently the only things that can have their length counted are a*, A*
2131 or Z*. See L<perlfunc/pack>.
2133 =item / must be followed by a, A or Z
2135 (F) You had an unpack template indicating a counted-length string, which
2136 must be followed by one of the letters a, A or Z to indicate what sort
2137 of string is to be unpacked. See L<perlfunc/pack>.
2139 =item / must follow a numeric type
2141 (F) You had an unpack template that contained a '#', but this did not
2142 follow some numeric unpack specification. See L<perlfunc/pack>.
2144 =item "my sub" not yet implemented
2146 (F) Lexically scoped subroutines are not yet implemented. Don't try
2149 =item "my" variable %s can't be in a package
2151 (F) Lexically scoped variables aren't in a package, so it doesn't make
2152 sense to try to declare one with a package qualifier on the front. Use
2153 local() if you want to localize a package variable.
2155 =item Name "%s::%s" used only once: possible typo
2157 (W once) Typographical errors often show up as unique variable names.
2158 If you had a good reason for having a unique name, then just mention it
2159 again somehow to suppress the message. The C<our> declaration is
2160 provided for this purpose.
2162 =item Negative length
2164 (F) You tried to do a read/write/send/recv operation with a buffer
2165 length that is less than 0. This is difficult to imagine.
2167 =item Negative offset to vec in lvalue context
2169 (F) When C<vec> is called in an lvalue context, the second argument must be
2170 greater than or equal to zero.
2172 =item Nested quantifiers in regex; marked by <-- HERE in m/%s/
2174 (F) You can't quantify a quantifier without intervening parentheses. So
2175 things like ** or +* or ?* are illegal. The <-- HERE shows in the regular
2176 expression about where the problem was discovered.
2178 Note that the minimal matching quantifiers, C<*?>, C<+?>, and
2179 C<??> appear to be nested quantifiers, but aren't. See L<perlre>.
2181 =item %s never introduced
2183 (S internal) The symbol in question was declared but somehow went out of
2184 scope before it could possibly have been used.
2186 =item No %s allowed while running setuid
2188 (F) Certain operations are deemed to be too insecure for a setuid or
2189 setgid script to even be allowed to attempt. Generally speaking there
2190 will be another way to do what you want that is, if not secure, at least
2191 securable. See L<perlsec>.
2193 =item No B<-e> allowed in setuid scripts
2195 (F) A setuid script can't be specified by the user.
2197 =item No comma allowed after %s
2199 (F) A list operator that has a filehandle or "indirect object" is not
2200 allowed to have a comma between that and the following arguments.
2201 Otherwise it'd be just another one of the arguments.
2203 One possible cause for this is that you expected to have imported a
2204 constant to your name space with B<use> or B<import> while no such
2205 importing took place, it may for example be that your operating system
2206 does not support that particular constant. Hopefully you did use an
2207 explicit import list for the constants you expect to see, please see
2208 L<perlfunc/use> and L<perlfunc/import>. While an explicit import list
2209 would probably have caught this error earlier it naturally does not
2210 remedy the fact that your operating system still does not support that
2211 constant. Maybe you have a typo in the constants of the symbol import
2212 list of B<use> or B<import> or in the constant name at the line where
2213 this error was triggered?
2215 =item No command into which to pipe on command line
2217 (F) An error peculiar to VMS. Perl handles its own command line
2218 redirection, and found a '|' at the end of the command line, so it
2219 doesn't know where you want to pipe the output from this command.
2221 =item No DB::DB routine defined
2223 (F) The currently executing code was compiled with the B<-d> switch, but
2224 for some reason the perl5db.pl file (or some facsimile thereof) didn't
2225 define a routine to be called at the beginning of each statement. Which
2226 is odd, because the file should have been required automatically, and
2227 should have blown up the require if it didn't parse right.
2229 =item No dbm on this machine
2231 (P) This is counted as an internal error, because every machine should
2232 supply dbm nowadays, because Perl comes with SDBM. See L<SDBM_File>.
2234 =item No DBsub routine
2236 (F) The currently executing code was compiled with the B<-d> switch,
2237 but for some reason the perl5db.pl file (or some facsimile thereof)
2238 didn't define a DB::sub routine to be called at the beginning of each
2239 ordinary subroutine call.
2241 =item No error file after 2> or 2>> on command line
2243 (F) An error peculiar to VMS. Perl handles its own command line
2244 redirection, and found a '2>' or a '2>>' on the command line, but can't
2245 find the name of the file to which to write data destined for stderr.
2247 =item No input file after < on command line
2249 (F) An error peculiar to VMS. Perl handles its own command line
2250 redirection, and found a '<' on the command line, but can't find the
2251 name of the file from which to read data for stdin.
2255 (F) The setuid emulator requires that scripts have a well-formed #! line
2256 even on machines that don't support the #! construct.
2258 =item "no" not allowed in expression
2260 (F) The "no" keyword is recognized and executed at compile time, and
2261 returns no useful value. See L<perlmod>.
2263 =item No output file after > on command line
2265 (F) An error peculiar to VMS. Perl handles its own command line
2266 redirection, and found a lone '>' at the end of the command line, so it
2267 doesn't know where you wanted to redirect stdout.
2269 =item No output file after > or >> on command line
2271 (F) An error peculiar to VMS. Perl handles its own command line
2272 redirection, and found a '>' or a '>>' on the command line, but can't
2273 find the name of the file to which to write data destined for stdout.
2275 =item No package name allowed for variable %s in "our"
2277 (F) Fully qualified variable names are not allowed in "our"
2278 declarations, because that doesn't make much sense under existing
2279 semantics. Such syntax is reserved for future extensions.
2281 =item No Perl script found in input
2283 (F) You called C<perl -x>, but no line was found in the file beginning
2284 with #! and containing the word "perl".
2286 =item No setregid available
2288 (F) Configure didn't find anything resembling the setregid() call for
2291 =item No setreuid available
2293 (F) Configure didn't find anything resembling the setreuid() call for
2296 =item No space allowed after -%c
2298 (F) The argument to the indicated command line switch must follow
2299 immediately after the switch, without intervening spaces.
2301 =item No %s specified for -%c
2303 (F) The indicated command line switch needs a mandatory argument, but
2304 you haven't specified one.
2306 =item No such class %s
2308 (F) You provided a class qualifier in a "my" or "our" declaration, but
2309 this class doesn't exist at this point in your program.
2311 =item No such pipe open
2313 (P) An error peculiar to VMS. The internal routine my_pclose() tried to
2314 close a pipe which hadn't been opened. This should have been caught
2315 earlier as an attempt to close an unopened filehandle.
2317 =item No such pseudo-hash field "%s"
2319 (F) You tried to access an array as a hash, but the field name used is
2320 not defined. The hash at index 0 should map all valid field names to
2321 array indices for that to work.
2323 =item No such pseudo-hash field "%s" in variable %s of type %s
2325 (F) You tried to access a field of a typed variable where the type does
2326 not know about the field name. The field names are looked up in the
2327 %FIELDS hash in the type package at compile time. The %FIELDS hash is
2328 %usually set up with the 'fields' pragma.
2330 =item No such signal: SIG%s
2332 (W signal) You specified a signal name as a subscript to %SIG that was
2333 not recognized. Say C<kill -l> in your shell to see the valid signal
2334 names on your system.
2336 =item Not a CODE reference
2338 (F) Perl was trying to evaluate a reference to a code value (that is, a
2339 subroutine), but found a reference to something else instead. You can
2340 use the ref() function to find out what kind of ref it really was. See
2343 =item Not a format reference
2345 (F) I'm not sure how you managed to generate a reference to an anonymous
2346 format, but this indicates you did, and that it didn't exist.
2348 =item Not a GLOB reference
2350 (F) Perl was trying to evaluate a reference to a "typeglob" (that is, a
2351 symbol table entry that looks like C<*foo>), but found a reference to
2352 something else instead. You can use the ref() function to find out what
2353 kind of ref it really was. See L<perlref>.
2355 =item Not a HASH reference
2357 (F) Perl was trying to evaluate a reference to a hash value, but found a
2358 reference to something else instead. You can use the ref() function to
2359 find out what kind of ref it really was. See L<perlref>.
2361 =item Not an ARRAY reference
2363 (F) Perl was trying to evaluate a reference to an array value, but found
2364 a reference to something else instead. You can use the ref() function
2365 to find out what kind of ref it really was. See L<perlref>.
2367 =item Not a perl script
2369 (F) The setuid emulator requires that scripts have a well-formed #! line
2370 even on machines that don't support the #! construct. The line must
2373 =item Not a SCALAR reference
2375 (F) Perl was trying to evaluate a reference to a scalar value, but found
2376 a reference to something else instead. You can use the ref() function
2377 to find out what kind of ref it really was. See L<perlref>.
2379 =item Not a subroutine reference
2381 (F) Perl was trying to evaluate a reference to a code value (that is, a
2382 subroutine), but found a reference to something else instead. You can
2383 use the ref() function to find out what kind of ref it really was. See
2386 =item Not a subroutine reference in overload table
2388 (F) An attempt was made to specify an entry in an overloading table that
2389 doesn't somehow point to a valid subroutine. See L<overload>.
2391 =item Not enough arguments for %s
2393 (F) The function requires more arguments than you specified.
2395 =item Not enough format arguments
2397 (W syntax) A format specified more picture fields than the next line
2398 supplied. See L<perlform>.
2402 (A) You've accidentally run your script through the Bourne shell instead
2403 of Perl. Check the #! line, or manually feed your script into Perl
2406 =item %s not allowed in length fields
2408 (F) The count in the (un)pack template may be replaced by C<[TEMPLATE]> only if
2409 C<TEMPLATE> always matches the same amount of packed bytes. Redesign
2412 =item no UTC offset information; assuming local time is UTC
2414 (S) A warning peculiar to VMS. Perl was unable to find the local
2415 timezone offset, so it's assuming that local system time is equivalent
2416 to UTC. If it's not, define the logical name
2417 F<SYS$TIMEZONE_DIFFERENTIAL> to translate to the number of seconds which
2418 need to be added to UTC to get local time.
2420 =item Null filename used
2422 (F) You can't require the null filename, especially because on many
2423 machines that means the current directory! See L<perlfunc/require>.
2425 =item NULL OP IN RUN
2427 (P debugging) Some internal routine called run() with a null opcode
2430 =item Null picture in formline
2432 (F) The first argument to formline must be a valid format picture
2433 specification. It was found to be empty, which probably means you
2434 supplied it an uninitialized value. See L<perlform>.
2438 (P) An attempt was made to realloc NULL.
2440 =item NULL regexp argument
2442 (P) The internal pattern matching routines blew it big time.
2444 =item NULL regexp parameter
2446 (P) The internal pattern matching routines are out of their gourd.
2448 =item Number too long
2450 (F) Perl limits the representation of decimal numbers in programs to
2451 about 250 characters. You've exceeded that length. Future
2452 versions of Perl are likely to eliminate this arbitrary limitation. In
2453 the meantime, try using scientific notation (e.g. "1e6" instead of
2456 =item Octal number in vector unsupported
2458 (F) Numbers with a leading C<0> are not currently allowed in vectors.
2459 The octal number interpretation of such numbers may be supported in a
2462 =item Octal number > 037777777777 non-portable
2464 (W portable) The octal number you specified is larger than 2**32-1
2465 (4294967295) and therefore non-portable between systems. See
2466 L<perlport> for more on portability concerns.
2468 See also L<perlport> for writing portable code.
2470 =item Odd number of arguments for overload::constant
2472 (W overload) The call to overload::constant contained an odd number of
2473 arguments. The arguments should come in pairs.
2475 =item Odd number of elements in anonymous hash
2477 (W misc) You specified an odd number of elements to initialize a hash,
2478 which is odd, because hashes come in key/value pairs.
2480 =item Odd number of elements in hash assignment
2482 (W misc) You specified an odd number of elements to initialize a hash,
2483 which is odd, because hashes come in key/value pairs.
2485 =item Offset outside string
2487 (F) You tried to do a read/write/send/recv operation with an offset
2488 pointing outside the buffer. This is difficult to imagine. The sole
2489 exception to this is that C<sysread()>ing past the buffer will extend
2490 the buffer and zero pad the new area.
2492 =item -%s on unopened filehandle %s
2494 (W unopened) You tried to invoke a file test operator on a filehandle
2495 that isn't open. Check your control flow. See also L<perlfunc/-X>.
2497 =item %s() on unopened %s
2499 (W unopened) An I/O operation was attempted on a filehandle that was
2500 never initialized. You need to do an open(), a sysopen(), or a socket()
2501 call, or call a constructor from the FileHandle package.
2505 (S internal) An internal warning that the grammar is screwed up.
2509 (S internal) An internal warning that the grammar is screwed up.
2511 =item Operation `%s': no method found, %s
2513 (F) An attempt was made to perform an overloaded operation for which no
2514 handler was defined. While some handlers can be autogenerated in terms
2515 of other handlers, there is no default handler for any operation, unless
2516 C<fallback> overloading key is specified to be true. See L<overload>.
2518 =item Operator or semicolon missing before %s
2520 (S ambiguous) You used a variable or subroutine call where the parser
2521 was expecting an operator. The parser has assumed you really meant to
2522 use an operator, but this is highly likely to be incorrect. For
2523 example, if you say "*foo *foo" it will be interpreted as if you said
2526 =item "our" variable %s redeclared
2528 (W misc) You seem to have already declared the same global once before
2529 in the current lexical scope.
2531 =item Out of memory!
2533 (X) The malloc() function returned 0, indicating there was insufficient
2534 remaining memory (or virtual memory) to satisfy the request. Perl has
2535 no option but to exit immediately.
2537 =item Out of memory during "large" request for %s
2539 (F) The malloc() function returned 0, indicating there was insufficient
2540 remaining memory (or virtual memory) to satisfy the request. However,
2541 the request was judged large enough (compile-time default is 64K), so a
2542 possibility to shut down by trapping this error is granted.
2544 =item Out of memory during request for %s
2546 (X|F) The malloc() function returned 0, indicating there was
2547 insufficient remaining memory (or virtual memory) to satisfy the
2550 The request was judged to be small, so the possibility to trap it
2551 depends on the way perl was compiled. By default it is not trappable.
2552 However, if compiled for this, Perl may use the contents of C<$^M> as an
2553 emergency pool after die()ing with this message. In this case the error
2554 is trappable I<once>, and the error message will include the line and file
2555 where the failed request happened.
2557 =item Out of memory during ridiculously large request
2559 (F) You can't allocate more than 2^31+"small amount" bytes. This error
2560 is most likely to be caused by a typo in the Perl program. e.g.,
2561 C<$arr[time]> instead of C<$arr[$time]>.
2563 =item Out of memory for yacc stack
2565 (F) The yacc parser wanted to grow its stack so it could continue
2566 parsing, but realloc() wouldn't give it more memory, virtual or
2569 =item @ outside of string
2571 (F) You had a pack template that specified an absolute position outside
2572 the string being unpacked. See L<perlfunc/pack>.
2574 =item %s package attribute may clash with future reserved word: %s
2576 (W reserved) A lowercase attribute name was used that had a
2577 package-specific handler. That name might have a meaning to Perl itself
2578 some day, even though it doesn't yet. Perhaps you should use a
2579 mixed-case attribute name, instead. See L<attributes>.
2583 (W io) A single call to write() produced more lines than can fit on a
2584 page. See L<perlform>.
2588 (P) An internal error.
2590 =item panic: ck_grep
2592 (P) Failed an internal consistency check trying to compile a grep.
2594 =item panic: ck_split
2596 (P) Failed an internal consistency check trying to compile a split.
2598 =item panic: corrupt saved stack index
2600 (P) The savestack was requested to restore more localized values than
2601 there are in the savestack.
2603 =item panic: del_backref
2605 (P) Failed an internal consistency check while trying to reset a weak
2610 (P) We popped the context stack to an eval context, and then discovered
2611 it wasn't an eval context.
2613 =item panic: pp_match%s
2615 (P) The internal pp_match() routine was called with invalid operational
2618 =item panic: do_subst
2620 (P) The internal pp_subst() routine was called with invalid operational
2623 =item panic: do_trans_%s
2625 (P) The internal do_trans routines were called with invalid operational
2630 (P) The library function frexp() failed, making printf("%f") impossible.
2634 (P) We popped the context stack to a context with the specified label,
2635 and then discovered it wasn't a context we know how to do a goto in.
2637 =item panic: INTERPCASEMOD
2639 (P) The lexer got into a bad state at a case modifier.
2641 =item panic: INTERPCONCAT
2643 (P) The lexer got into a bad state parsing a string with brackets.
2645 =item panic: kid popen errno read
2647 (F) forked child returned an incomprehensible message about its errno.
2651 (P) We popped the context stack to a block context, and then discovered
2652 it wasn't a block context.
2654 =item panic: leave_scope clearsv
2656 (P) A writable lexical variable became read-only somehow within the
2659 =item panic: leave_scope inconsistency
2661 (P) The savestack probably got out of sync. At least, there was an
2662 invalid enum on the top of it.
2664 =item panic: magic_killbackrefs
2666 (P) Failed an internal consistency check while trying to reset all weak
2667 references to an object.
2671 (P) Something requested a negative number of bytes of malloc.
2673 =item panic: mapstart
2675 (P) The compiler is screwed up with respect to the map() function.
2677 =item panic: null array
2679 (P) One of the internal array routines was passed a null AV pointer.
2681 =item panic: pad_alloc
2683 (P) The compiler got confused about which scratch pad it was allocating
2684 and freeing temporaries and lexicals from.
2686 =item panic: pad_free curpad
2688 (P) The compiler got confused about which scratch pad it was allocating
2689 and freeing temporaries and lexicals from.
2691 =item panic: pad_free po
2693 (P) An invalid scratch pad offset was detected internally.
2695 =item panic: pad_reset curpad
2697 (P) The compiler got confused about which scratch pad it was allocating
2698 and freeing temporaries and lexicals from.
2700 =item panic: pad_sv po
2702 (P) An invalid scratch pad offset was detected internally.
2704 =item panic: pad_swipe curpad
2706 (P) The compiler got confused about which scratch pad it was allocating
2707 and freeing temporaries and lexicals from.
2709 =item panic: pad_swipe po
2711 (P) An invalid scratch pad offset was detected internally.
2713 =item panic: pp_iter
2715 (P) The foreach iterator got called in a non-loop context frame.
2717 =item panic: pp_split
2719 (P) Something terrible went wrong in setting up for the split.
2721 =item panic: realloc
2723 (P) Something requested a negative number of bytes of realloc.
2725 =item panic: restartop
2727 (P) Some internal routine requested a goto (or something like it), and
2728 didn't supply the destination.
2732 (P) We popped the context stack to a subroutine or eval context, and
2733 then discovered it wasn't a subroutine or eval context.
2735 =item panic: scan_num
2737 (P) scan_num() got called on something that wasn't a number.
2739 =item panic: sv_insert
2741 (P) The sv_insert() routine was told to remove more string than there
2744 =item panic: top_env
2746 (P) The compiler attempted to do a goto, or something weird like that.
2750 (P) The lexer got into a bad state while processing a case modifier.
2752 =item panic: utf16_to_utf8: odd bytelen
2754 (P) Something tried to call utf16_to_utf8 with an odd (as opposed
2755 to even) byte length.
2757 =item Parentheses missing around "%s" list
2759 (W parenthesis) You said something like
2765 my ($foo, $bar) = @_;
2767 Remember that "my", "our", and "local" bind tighter than comma.
2769 =item Perl %s required--this is only version %s, stopped
2771 (F) The module in question uses features of a version of Perl more
2772 recent than the currently running version. How long has it been since
2773 you upgraded, anyway? See L<perlfunc/require>.
2775 =item PERL_SH_DIR too long
2777 (F) An error peculiar to OS/2. PERL_SH_DIR is the directory to find the
2778 C<sh>-shell in. See "PERL_SH_DIR" in L<perlos2>.
2780 =item perl: warning: Setting locale failed.
2782 (S) The whole warning message will look something like:
2784 perl: warning: Setting locale failed.
2785 perl: warning: Please check that your locale settings:
2788 are supported and installed on your system.
2789 perl: warning: Falling back to the standard locale ("C").
2791 Exactly what were the failed locale settings varies. In the above the
2792 settings were that the LC_ALL was "En_US" and the LANG had no value.
2793 This error means that Perl detected that you and/or your operating
2794 system supplier and/or system administrator have set up the so-called
2795 locale system but Perl could not use those settings. This was not
2796 dead serious, fortunately: there is a "default locale" called "C" that
2797 Perl can and will use, the script will be run. Before you really fix
2798 the problem, however, you will get the same error message each time
2799 you run Perl. How to really fix the problem can be found in
2800 L<perllocale> section B<LOCALE PROBLEMS>.
2802 =item perlio: argument list not closed for layer "%s"
2804 (S) When pushing a layer with arguments onto the Perl I/O system you forgot
2805 the ) that closes the argument list. (Layers take care of transforming
2806 data between external and internal representations.) Perl stopped parsing
2807 the layer list at this point and did not attempt to push this layer.
2808 If your program didn't explicitly request the failing operation, it may be
2809 the result of the value of the environment variable PERLIO.
2811 =item perlio: invalid separator character %s in attribute list
2813 (S) When pushing layers onto the Perl I/O system, something other than a
2814 colon or whitespace was seen between the elements of a layer list.
2815 If the previous attribute had a parenthesised parameter list, perhaps that
2816 list was terminated too soon.
2818 =item perlio: unknown layer "%s"
2820 (S) An attempt was made to push an unknown layer onto the Perl I/O
2821 system. (Layers take care of transforming data between external and
2822 internal representations.) Note that some layers, such as C<mmap>,
2823 are not supported in all environments. If your program didn't
2824 explicitly request the failing operation, it may be the result of the
2825 value of the environment variable PERLIO.
2827 =item Permission denied
2829 (F) The setuid emulator in suidperl decided you were up to no good.
2831 =item pid %x not a child
2833 (W exec) A warning peculiar to VMS. Waitpid() was asked to wait for a
2834 process which isn't a subprocess of the current process. While this is
2835 fine from VMS' perspective, it's probably not what you intended.
2837 =item P must have an explicit size
2839 (F) The unpack format P must have an explicit size, not "*".
2841 =item POSIX syntax [%s] belongs inside character classes in regex;
2843 marked by <-- HERE in m/%s/
2845 (W regexp) The character class constructs [: :], [= =], and [. .] go
2846 I<inside> character classes, the [] are part of the construct, for example:
2847 /[012[:alpha:]345]/. Note that [= =] and [. .] are not currently
2848 implemented; they are simply placeholders for future extensions and will
2849 cause fatal errors. The <-- HERE shows in the regular expression about
2850 where the problem was discovered. See L<perlre>.
2852 =item POSIX syntax [. .] is reserved for future extensions in regex;
2854 marked by <-- HERE in m/%s/
2856 (F regexp) Within regular expression character classes ([]) the syntax
2857 beginning with "[." and ending with ".]" is reserved for future extensions.
2858 If you need to represent those character sequences inside a regular
2859 expression character class, just quote the square brackets with the
2860 backslash: "\[." and ".\]". The <-- HERE shows in the regular expression
2861 about where the problem was discovered. See L<perlre>.
2863 =item POSIX syntax [= =] is reserved for future extensions in regex;
2865 marked by <-- HERE in m/%s/
2867 (F) Within regular expression character classes ([]) the syntax beginning
2868 with "[=" and ending with "=]" is reserved for future extensions. If you
2869 need to represent those character sequences inside a regular expression
2870 character class, just quote the square brackets with the backslash: "\[="
2871 and "=\]". The <-- HERE shows in the regular expression about where the
2872 problem was discovered. See L<perlre>.
2874 =item POSIX class [:%s:] unknown in regex;
2876 marked by <-- HERE in m/%s/
2878 (F) The class in the character class [: :] syntax is unknown. The <-- HERE
2879 shows in the regular expression about where the problem was discovered.
2880 Note that the POSIX character classes do B<not> have the C<is> prefix
2881 the corresponding C interfaces have: in other words, it's C<[[:print:]]>,
2882 not C<isprint>. See L<perlre>.
2884 =item POSIX getpgrp can't take an argument
2886 (F) Your system has POSIX getpgrp(), which takes no argument, unlike
2887 the BSD version, which takes a pid.
2889 =item Possible attempt to put comments in qw() list
2891 (W qw) qw() lists contain items separated by whitespace; as with literal
2892 strings, comment characters are not ignored, but are instead treated as
2893 literal data. (You may have used different delimiters than the
2894 parentheses shown here; braces are also frequently used.)
2896 You probably wrote something like this:
2903 when you should have written this:
2910 If you really want comments, build your list the
2911 old-fashioned way, with quotes and commas:
2915 'b', # another comment
2918 =item Possible attempt to separate words with commas
2920 (W qw) qw() lists contain items separated by whitespace; therefore
2921 commas aren't needed to separate the items. (You may have used
2922 different delimiters than the parentheses shown here; braces are also
2925 You probably wrote something like this:
2929 which puts literal commas into some of the list items. Write it without
2930 commas if you don't want them to appear in your data:
2934 =item Possible memory corruption: %s overflowed 3rd argument
2936 (F) An ioctl() or fcntl() returned more than Perl was bargaining for.
2937 Perl guesses a reasonable buffer size, but puts a sentinel byte at the
2938 end of the buffer just in case. This sentinel byte got clobbered, and
2939 Perl assumes that memory is now corrupted. See L<perlfunc/ioctl>.
2941 =item Possible unintended interpolation of %s in string
2943 (W ambiguous) You said something like `@foo' in a double-quoted string
2944 but there was no array C<@foo> in scope at the time. If you wanted a
2945 literal @foo, then write it as \@foo; otherwise find out what happened
2946 to the array you apparently lost track of.
2948 =item Possible Y2K bug: %s
2950 (W y2k) You are concatenating the number 19 with another number, which
2951 could be a potential Year 2000 problem.
2953 =item pragma "attrs" is deprecated, use "sub NAME : ATTRS" instead
2955 (D deprecated) You have written something like this:
2959 use attrs qw(locked);
2962 You should use the new declaration syntax instead.
2968 The C<use attrs> pragma is now obsolete, and is only provided for
2969 backward-compatibility. See L<perlsub/"Subroutine Attributes">.
2971 =item Precedence problem: open %s should be open(%s)
2973 (S precedence) The old irregular construct
2977 is now misinterpreted as
2981 because of the strict regularization of Perl 5's grammar into unary and
2982 list operators. (The old open was a little of both.) You must put
2983 parentheses around the filehandle, or use the new "or" operator instead
2986 =item Premature end of script headers
2990 =item printf() on closed filehandle %s
2992 (W closed) The filehandle you're writing to got itself closed sometime
2993 before now. Check your control flow.
2995 =item print() on closed filehandle %s
2997 (W closed) The filehandle you're printing on got itself closed sometime
2998 before now. Check your control flow.
3000 =item Process terminated by SIG%s
3002 (W) This is a standard message issued by OS/2 applications, while *nix
3003 applications die in silence. It is considered a feature of the OS/2
3004 port. One can easily disable this by appropriate sighandlers, see
3005 L<perlipc/"Signals">. See also "Process terminated by SIGTERM/SIGINT"
3008 =item Prototype mismatch: %s vs %s
3010 (S prototype) The subroutine being declared or defined had previously been
3011 declared or defined with a different function prototype.
3013 =item Prototype not terminated
3015 (F) You've omitted the closing parenthesis in a function prototype
3018 =item Quantifier in {,} bigger than %d in regex;
3020 marked by <-- HERE in m/%s/
3022 (F) There is currently a limit to the size of the min and max values of the
3023 {min,max} construct. The <-- HERE shows in the regular expression about where
3024 the problem was discovered. See L<perlre>.
3026 =item Quantifier unexpected on zero-length expression;
3028 marked by <-- HERE in m/%s/
3030 (W regexp) You applied a regular expression quantifier in a place where
3031 it makes no sense, such as on a zero-width assertion. Try putting the
3032 quantifier inside the assertion instead. For example, the way to match
3033 "abc" provided that it is followed by three repetitions of "xyz" is
3034 C</abc(?=(?:xyz){3})/>, not C</abc(?=xyz){3}/>.
3036 The <-- HERE shows in the regular expression about where the problem was
3039 =item Range iterator outside integer range
3041 (F) One (or both) of the numeric arguments to the range operator ".."
3042 are outside the range which can be represented by integers internally.
3043 One possible workaround is to force Perl to use magical string increment
3044 by prepending "0" to your numbers.
3046 =item readline() on closed filehandle %s
3048 (W closed) The filehandle you're reading from got itself closed sometime
3049 before now. Check your control flow.
3051 =item Reallocation too large: %lx
3053 (F) You can't allocate more than 64K on an MS-DOS machine.
3055 =item realloc() of freed memory ignored
3057 (S malloc) An internal routine called realloc() on something that had
3060 =item Recompile perl with B<-D>DEBUGGING to use B<-D> switch
3062 (F debugging) You can't use the B<-D> option unless the code to produce
3063 the desired output is compiled into Perl, which entails some overhead,
3064 which is why it's currently left out of your copy.
3066 =item Recursive inheritance detected in package '%s'
3068 (F) More than 100 levels of inheritance were used. Probably indicates
3069 an unintended loop in your inheritance hierarchy.
3071 =item Recursive inheritance detected while looking for method %s
3073 (F) More than 100 levels of inheritance were encountered while invoking
3074 a method. Probably indicates an unintended loop in your inheritance
3077 =item Reference found where even-sized list expected
3079 (W misc) You gave a single reference where Perl was expecting a list
3080 with an even number of elements (for assignment to a hash). This usually
3081 means that you used the anon hash constructor when you meant to use
3082 parens. In any case, a hash requires key/value B<pairs>.
3084 %hash = { one => 1, two => 2, }; # WRONG
3085 %hash = [ qw/ an anon array / ]; # WRONG
3086 %hash = ( one => 1, two => 2, ); # right
3087 %hash = qw( one 1 two 2 ); # also fine
3089 =item Reference is already weak
3091 (W misc) You have attempted to weaken a reference that is already weak.
3092 Doing so has no effect.
3094 =item Reference miscount in sv_replace()
3096 (W internal) The internal sv_replace() function was handed a new SV with
3097 a reference count of other than 1.
3099 =item Reference to nonexistent group in regex;
3101 marked by <-- HERE in m/%s/
3103 (F) You used something like C<\7> in your regular expression, but there are
3104 not at least seven sets of capturing parentheses in the expression. If you
3105 wanted to have the character with value 7 inserted into the regular expression,
3106 prepend a zero to make the number at least two digits: C<\07>
3108 The <-- HERE shows in the regular expression about where the problem was
3111 =item regexp memory corruption
3113 (P) The regular expression engine got confused by what the regular
3114 expression compiler gave it.
3116 =item Regexp out of space
3118 (P) A "can't happen" error, because safemalloc() should have caught it
3121 =item Repeat count in pack overflows
3123 (F) You can't specify a repeat count so large that it overflows your
3124 signed integers. See L<perlfunc/pack>.
3126 =item Repeat count in unpack overflows
3128 (F) You can't specify a repeat count so large that it overflows your
3129 signed integers. See L<perlfunc/unpack>.
3131 =item Reversed %s= operator
3133 (W syntax) You wrote your assignment operator backwards. The = must
3134 always comes last, to avoid ambiguity with subsequent unary operators.
3136 =item Runaway format
3138 (F) Your format contained the ~~ repeat-until-blank sequence, but it
3139 produced 200 lines at once, and the 200th line looked exactly like the
3140 199th line. Apparently you didn't arrange for the arguments to exhaust
3141 themselves, either by using ^ instead of @ (for scalar variables), or by
3142 shifting or popping (for array variables). See L<perlform>.
3144 =item Scalar value @%s[%s] better written as $%s[%s]
3146 (W syntax) You've used an array slice (indicated by @) to select a
3147 single element of an array. Generally it's better to ask for a scalar
3148 value (indicated by $). The difference is that C<$foo[&bar]> always
3149 behaves like a scalar, both when assigning to it and when evaluating its
3150 argument, while C<@foo[&bar]> behaves like a list when you assign to it,
3151 and provides a list context to its subscript, which can do weird things
3152 if you're expecting only one subscript.
3154 On the other hand, if you were actually hoping to treat the array
3155 element as a list, you need to look into how references work, because
3156 Perl will not magically convert between scalars and lists for you. See
3159 =item Scalar value @%s{%s} better written as $%s{%s}
3161 (W syntax) You've used a hash slice (indicated by @) to select a single
3162 element of a hash. Generally it's better to ask for a scalar value
3163 (indicated by $). The difference is that C<$foo{&bar}> always behaves
3164 like a scalar, both when assigning to it and when evaluating its
3165 argument, while C<@foo{&bar}> behaves like a list when you assign to it,
3166 and provides a list context to its subscript, which can do weird things
3167 if you're expecting only one subscript.
3169 On the other hand, if you were actually hoping to treat the hash element
3170 as a list, you need to look into how references work, because Perl will
3171 not magically convert between scalars and lists for you. See
3174 =item Scalars leaked: %d
3176 (P) Something went wrong in Perl's internal bookkeeping of scalars:
3177 not all scalar variables were deallocated by the time Perl exited.
3178 What this usually indicates is a memory leak, which is of course bad,
3179 especially if the Perl program is intended to be long-running.
3181 =item Script is not setuid/setgid in suidperl
3183 (F) Oddly, the suidperl program was invoked on a script without a setuid
3184 or setgid bit set. This doesn't make much sense.
3186 =item Search pattern not terminated
3188 (F) The lexer couldn't find the final delimiter of a // or m{}
3189 construct. Remember that bracketing delimiters count nesting level.
3190 Missing the leading C<$> from a variable C<$m> may cause this error.
3192 =item %sseek() on unopened filehandle
3194 (W unopened) You tried to use the seek() or sysseek() function on a
3195 filehandle that was either never opened or has since been closed.
3197 =item select not implemented
3199 (F) This machine doesn't implement the select() system call.
3201 =item Self-ties of arrays and hashes are not supported
3203 (F) Self-ties are of arrays and hashes are not supported in
3204 the current implementation.
3206 =item Semicolon seems to be missing
3208 (W semicolon) A nearby syntax error was probably caused by a missing
3209 semicolon, or possibly some other missing operator, such as a comma.
3211 =item semi-panic: attempt to dup freed string
3213 (S internal) The internal newSVsv() routine was called to duplicate a
3214 scalar that had previously been marked as free.
3216 =item sem%s not implemented
3218 (F) You don't have System V semaphore IPC on your system.
3220 =item send() on closed socket %s
3222 (W closed) The socket you're sending to got itself closed sometime
3223 before now. Check your control flow.
3225 =item Sequence (? incomplete in regex; marked by <-- HERE in m/%s/
3227 (F) A regular expression ended with an incomplete extension (?. The <-- HERE
3228 shows in the regular expression about where the problem was discovered. See
3231 =item Sequence (?{...}) not terminated or not {}-balanced in regex;
3233 marked by <-- HERE in m/%s/
3235 (F) If the contents of a (?{...}) clause contains braces, they must balance
3236 for Perl to properly detect the end of the clause. The <-- HERE shows in
3237 the regular expression about where the problem was discovered. See
3240 =item Sequence (?%s...) not implemented in regex;
3242 marked by <-- HERE in m/%s/
3244 (F) A proposed regular expression extension has the character reserved but
3245 has not yet been written. The <-- HERE shows in the regular expression about
3246 where the problem was discovered. See L<perlre>.
3248 =item Sequence (?%s...) not recognized in regex;
3250 marked by <-- HERE in m/%s/
3252 (F) You used a regular expression extension that doesn't make sense. The
3253 <-- HERE shows in the regular expression about where the problem was
3254 discovered. See L<perlre>.
3256 =item Sequence (?#... not terminated in regex;
3258 marked by <-- HERE in m/%s/
3260 (F) A regular expression comment must be terminated by a closing
3261 parenthesis. Embedded parentheses aren't allowed. The <-- HERE shows in
3262 the regular expression about where the problem was discovered. See
3265 =item 500 Server error
3271 This is the error message generally seen in a browser window when trying
3272 to run a CGI program (including SSI) over the web. The actual error text
3273 varies widely from server to server. The most frequently-seen variants
3274 are "500 Server error", "Method (something) not permitted", "Document
3275 contains no data", "Premature end of script headers", and "Did not
3276 produce a valid header".
3278 B<This is a CGI error, not a Perl error>.
3280 You need to make sure your script is executable, is accessible by the
3281 user CGI is running the script under (which is probably not the user
3282 account you tested it under), does not rely on any environment variables
3283 (like PATH) from the user it isn't running under, and isn't in a
3284 location where the CGI server can't find it, basically, more or less.
3285 Please see the following for more information:
3287 http://www.perl.org/CGI_MetaFAQ.html
3288 http://www.htmlhelp.org/faq/cgifaq.html
3289 http://www.w3.org/Security/Faq/
3291 You should also look at L<perlfaq9>.
3293 =item setegid() not implemented
3295 (F) You tried to assign to C<$)>, and your operating system doesn't
3296 support the setegid() system call (or equivalent), or at least Configure
3299 =item seteuid() not implemented
3301 (F) You tried to assign to C<< $> >>, and your operating system doesn't
3302 support the seteuid() system call (or equivalent), or at least Configure
3305 =item setpgrp can't take arguments
3307 (F) Your system has the setpgrp() from BSD 4.2, which takes no
3308 arguments, unlike POSIX setpgid(), which takes a process ID and process
3311 =item setrgid() not implemented
3313 (F) You tried to assign to C<$(>, and your operating system doesn't
3314 support the setrgid() system call (or equivalent), or at least Configure
3317 =item setruid() not implemented
3319 (F) You tried to assign to C<$<>, and your operating system doesn't
3320 support the setruid() system call (or equivalent), or at least Configure
3323 =item setsockopt() on closed socket %s
3325 (W closed) You tried to set a socket option on a closed socket. Did you
3326 forget to check the return value of your socket() call? See
3327 L<perlfunc/setsockopt>.
3329 =item Setuid/gid script is writable by world
3331 (F) The setuid emulator won't run a script that is writable by the
3332 world, because the world might have written on it already.
3334 =item shm%s not implemented
3336 (F) You don't have System V shared memory IPC on your system.
3338 =item <> should be quotes
3340 (F) You wrote C<< require <file> >> when you should have written
3343 =item /%s/ should probably be written as "%s"
3345 (W syntax) You have used a pattern where Perl expected to find a string,
3346 as in the first argument to C<join>. Perl will treat the true or false
3347 result of matching the pattern against $_ as the string, which is
3348 probably not what you had in mind.
3350 =item shutdown() on closed socket %s
3352 (W closed) You tried to do a shutdown on a closed socket. Seems a bit
3355 =item SIG%s handler "%s" not defined
3357 (W signal) The signal handler named in %SIG doesn't, in fact, exist.
3358 Perhaps you put it into the wrong package?
3360 =item sort is now a reserved word
3362 (F) An ancient error message that almost nobody ever runs into anymore.
3363 But before sort was a keyword, people sometimes used it as a filehandle.
3365 =item Sort subroutine didn't return a numeric value
3367 (F) A sort comparison routine must return a number. You probably blew
3368 it by not using C<< <=> >> or C<cmp>, or by not using them correctly.
3369 See L<perlfunc/sort>.
3371 =item Sort subroutine didn't return single value
3373 (F) A sort comparison subroutine may not return a list value with more
3374 or less than one element. See L<perlfunc/sort>.
3376 =item splice() offset past end of array
3378 (W misc) You attempted to specify an offset that was past the end of
3379 the array passed to splice(). Splicing will instead commence at the end
3380 of the array, rather than past it. If this isn't what you want, try
3381 explicitly pre-extending the array by assigning $#array = $offset. See
3386 (P) The split was looping infinitely. (Obviously, a split shouldn't
3387 iterate more times than there are characters of input, which is what
3388 happened.) See L<perlfunc/split>.
3390 =item Statement unlikely to be reached
3392 (W exec) You did an exec() with some statement after it other than a
3393 die(). This is almost always an error, because exec() never returns
3394 unless there was a failure. You probably wanted to use system()
3395 instead, which does return. To suppress this warning, put the exec() in
3398 =item stat() on unopened filehandle %s
3400 (W unopened) You tried to use the stat() function on a filehandle that
3401 was either never opened or has since been closed.
3403 =item Stub found while resolving method `%s' overloading %s
3405 (P) Overloading resolution over @ISA tree may be broken by importation
3406 stubs. Stubs should never be implicitly created, but explicit calls to
3407 C<can> may break this.
3409 =item Subroutine %s redefined
3411 (W redefine) You redefined a subroutine. To suppress this warning, say
3414 no warnings 'redefine';
3415 eval "sub name { ... }";
3418 =item Substitution loop
3420 (P) The substitution was looping infinitely. (Obviously, a substitution
3421 shouldn't iterate more times than there are characters of input, which
3422 is what happened.) See the discussion of substitution in
3423 L<perlop/"Quote and Quote-like Operators">.
3425 =item Substitution pattern not terminated
3427 (F) The lexer couldn't find the interior delimiter of an s/// or s{}{}
3428 construct. Remember that bracketing delimiters count nesting level.
3429 Missing the leading C<$> from variable C<$s> may cause this error.
3431 =item Substitution replacement not terminated
3433 (F) The lexer couldn't find the final delimiter of an s/// or s{}{}
3434 construct. Remember that bracketing delimiters count nesting level.
3435 Missing the leading C<$> from variable C<$s> may cause this error.
3437 =item substr outside of string
3439 (W substr),(F) You tried to reference a substr() that pointed outside of
3440 a string. That is, the absolute value of the offset was larger than the
3441 length of the string. See L<perlfunc/substr>. This warning is fatal if
3442 substr is used in an lvalue context (as the left hand side of an
3443 assignment or as a subroutine argument for example).
3445 =item suidperl is no longer needed since %s
3447 (F) Your Perl was compiled with B<-D>SETUID_SCRIPTS_ARE_SECURE_NOW, but
3448 a version of the setuid emulator somehow got run anyway.
3450 =item Switch (?(condition)... contains too many branches in regex;
3452 marked by <-- HERE in m/%s/
3454 (F) A (?(condition)if-clause|else-clause) construct can have at most two
3455 branches (the if-clause and the else-clause). If you want one or both to
3456 contain alternation, such as using C<this|that|other>, enclose it in
3457 clustering parentheses:
3459 (?(condition)(?:this|that|other)|else-clause)
3461 The <-- HERE shows in the regular expression about where the problem was
3462 discovered. See L<perlre>.
3464 =item Switch condition not recognized in regex;
3466 marked by <-- HERE in m/%s/
3468 (F) If the argument to the (?(...)if-clause|else-clause) construct is a
3469 number, it can be only a number. The <-- HERE shows in the regular expression
3470 about where the problem was discovered. See L<perlre>.
3472 =item switching effective %s is not implemented
3474 (F) While under the C<use filetest> pragma, we cannot switch the real
3475 and effective uids or gids.
3479 (F) Probably means you had a syntax error. Common reasons include:
3481 A keyword is misspelled.
3482 A semicolon is missing.
3484 An opening or closing parenthesis is missing.
3485 An opening or closing brace is missing.
3486 A closing quote is missing.
3488 Often there will be another error message associated with the syntax
3489 error giving more information. (Sometimes it helps to turn on B<-w>.)
3490 The error message itself often tells you where it was in the line when
3491 it decided to give up. Sometimes the actual error is several tokens
3492 before this, because Perl is good at understanding random input.
3493 Occasionally the line number may be misleading, and once in a blue moon
3494 the only way to figure out what's triggering the error is to call
3495 C<perl -c> repeatedly, chopping away half the program each time to see
3496 if the error went away. Sort of the cybernetic version of S<20
3499 =item syntax error at line %d: `%s' unexpected
3501 (A) You've accidentally run your script through the Bourne shell instead
3502 of Perl. Check the #! line, or manually feed your script into Perl
3505 =item syntax error in file %s at line %d, next 2 tokens "%s"
3507 (F) This error is likely to occur if you run a perl5 script through
3508 a perl4 interpreter, especially if the next 2 tokens are "use strict"
3509 or "my $var" or "our $var".
3513 (F) The final summary message when a C<perl -c> succeeds.
3515 =item System V %s is not implemented on this machine
3517 (F) You tried to do something with a function beginning with "sem",
3518 "shm", or "msg" but that System V IPC is not implemented in your
3519 machine. In some machines the functionality can exist but be
3520 unconfigured. Consult your system support.
3522 =item syswrite() on closed filehandle %s
3524 (W closed) The filehandle you're writing to got itself closed sometime
3525 before now. Check your control flow.
3527 =item Target of goto is too deeply nested
3529 (F) You tried to use C<goto> to reach a label that was too deeply nested
3530 for Perl to reach. Perl is doing you a favor by refusing.
3532 =item tell() on unopened filehandle
3534 (W unopened) You tried to use the tell() function on a filehandle that
3535 was either never opened or has since been closed.
3537 =item That use of $[ is unsupported
3539 (F) Assignment to C<$[> is now strictly circumscribed, and interpreted
3540 as a compiler directive. You may say only one of
3549 This is to prevent the problem of one module changing the array base out
3550 from under another module inadvertently. See L<perlvar/$[>.
3552 =item The crypt() function is unimplemented due to excessive paranoia
3554 (F) Configure couldn't find the crypt() function on your machine,
3555 probably because your vendor didn't supply it, probably because they
3556 think the U.S. Government thinks it's a secret, or at least that they
3557 will continue to pretend that it is. And if you quote me on that, I
3560 =item The %s function is unimplemented
3562 The function indicated isn't implemented on this architecture, according
3563 to the probings of Configure.
3565 =item The stat preceding %s wasn't an lstat
3567 (F) It makes no sense to test the current stat buffer for symbolic
3568 linkhood if the last stat that wrote to the stat buffer already went
3569 past the symlink to get to the real file. Use an actual filename
3572 =item This Perl can't reset CRTL environ elements (%s)
3574 =item This Perl can't set CRTL environ elements (%s=%s)
3576 (W internal) Warnings peculiar to VMS. You tried to change or delete an
3577 element of the CRTL's internal environ array, but your copy of Perl
3578 wasn't built with a CRTL that contained the setenv() function. You'll
3579 need to rebuild Perl with a CRTL that does, or redefine
3580 F<PERL_ENV_TABLES> (see L<perlvms>) so that the environ array isn't the
3581 target of the change to
3582 %ENV which produced the warning.
3584 =item times not implemented
3586 (F) Your version of the C library apparently doesn't do times(). I
3587 suspect you're not running on Unix.
3589 =item Too few args to syscall
3591 (F) There has to be at least one argument to syscall() to specify the
3592 system call to call, silly dilly.
3594 =item Too late for "B<-T>" option
3596 (X) The #! line (or local equivalent) in a Perl script contains the
3597 B<-T> option, but Perl was not invoked with B<-T> in its command line.
3598 This is an error because, by the time Perl discovers a B<-T> in a
3599 script, it's too late to properly taint everything from the environment.
3602 If the Perl script is being executed as a command using the #!
3603 mechanism (or its local equivalent), this error can usually be fixed by
3604 editing the #! line so that the B<-T> option is a part of Perl's first
3605 argument: e.g. change C<perl -n -T> to C<perl -T -n>.
3607 If the Perl script is being executed as C<perl scriptname>, then the
3608 B<-T> option must appear on the command line: C<perl -T scriptname>.
3610 =item Too late for "-%s" option
3612 (X) The #! line (or local equivalent) in a Perl script contains the
3613 B<-M> or B<-m> option. This is an error because B<-M> and B<-m> options
3614 are not intended for use inside scripts. Use the C<use> pragma instead.
3616 =item Too late to run %s block
3618 (W void) A CHECK or INIT block is being defined during run time proper,
3619 when the opportunity to run them has already passed. Perhaps you are
3620 loading a file with C<require> or C<do> when you should be using C<use>
3621 instead. Or perhaps you should put the C<require> or C<do> inside a
3624 =item Too many args to syscall
3626 (F) Perl supports a maximum of only 14 args to syscall().
3628 =item Too many arguments for %s
3630 (F) The function requires fewer arguments than you specified.
3636 (A) You've accidentally run your script through B<csh> instead of Perl.
3637 Check the #! line, or manually feed your script into Perl yourself.
3639 =item Trailing \ in regex m/%s/
3641 (F) The regular expression ends with an unbackslashed backslash.
3642 Backslash it. See L<perlre>.
3644 =item Transliteration pattern not terminated
3646 (F) The lexer couldn't find the interior delimiter of a tr/// or tr[][]
3647 or y/// or y[][] construct. Missing the leading C<$> from variables
3648 C<$tr> or C<$y> may cause this error.
3650 =item Transliteration replacement not terminated
3652 (F) The lexer couldn't find the final delimiter of a tr/// or tr[][]
3655 =item truncate not implemented
3657 (F) Your machine doesn't implement a file truncation mechanism that
3658 Configure knows about.
3660 =item Type of arg %d to %s must be %s (not %s)
3662 (F) This function requires the argument in that position to be of a
3663 certain type. Arrays must be @NAME or C<@{EXPR}>. Hashes must be
3664 %NAME or C<%{EXPR}>. No implicit dereferencing is allowed--use the
3665 {EXPR} forms as an explicit dereference. See L<perlref>.
3667 =item umask not implemented
3669 (F) Your machine doesn't implement the umask function and you tried to
3670 use it to restrict permissions for yourself (EXPR & 0700).
3672 =item Unable to create sub named "%s"
3674 (F) You attempted to create or access a subroutine with an illegal name.
3676 =item Unbalanced context: %d more PUSHes than POPs
3678 (W internal) The exit code detected an internal inconsistency in how
3679 many execution contexts were entered and left.
3681 =item Unbalanced saves: %d more saves than restores
3683 (W internal) The exit code detected an internal inconsistency in how
3684 many values were temporarily localized.
3686 =item Unbalanced scopes: %d more ENTERs than LEAVEs
3688 (W internal) The exit code detected an internal inconsistency in how
3689 many blocks were entered and left.
3691 =item Unbalanced tmps: %d more allocs than frees
3693 (W internal) The exit code detected an internal inconsistency in how
3694 many mortal scalars were allocated and freed.
3696 =item Undefined format "%s" called
3698 (F) The format indicated doesn't seem to exist. Perhaps it's really in
3699 another package? See L<perlform>.
3701 =item Undefined sort subroutine "%s" called
3703 (F) The sort comparison routine specified doesn't seem to exist.
3704 Perhaps it's in a different package? See L<perlfunc/sort>.
3706 =item Undefined subroutine &%s called
3708 (F) The subroutine indicated hasn't been defined, or if it was, it has
3709 since been undefined.
3711 =item Undefined subroutine called
3713 (F) The anonymous subroutine you're trying to call hasn't been defined,
3714 or if it was, it has since been undefined.
3716 =item Undefined subroutine in sort
3718 (F) The sort comparison routine specified is declared but doesn't seem
3719 to have been defined yet. See L<perlfunc/sort>.
3721 =item Undefined top format "%s" called
3723 (F) The format indicated doesn't seem to exist. Perhaps it's really in
3724 another package? See L<perlform>.
3726 =item Undefined value assigned to typeglob
3728 (W misc) An undefined value was assigned to a typeglob, a la
3729 C<*foo = undef>. This does nothing. It's possible that you really mean
3732 =item %s: Undefined variable
3734 (A) You've accidentally run your script through B<csh> instead of Perl.
3735 Check the #! line, or manually feed your script into Perl yourself.
3737 =item unexec of %s into %s failed!
3739 (F) The unexec() routine failed for some reason. See your local FSF
3740 representative, who probably put it there in the first place.
3742 =item Unicode character %s is illegal
3744 (W utf8) Certain Unicode characters have been designated off-limits by
3745 the Unicode standard and should not be generated. If you really know
3746 what you are doing you can turn off this warning by C<no warnings 'utf8';>.
3748 =item Unknown BYTEORDER
3750 (F) There are no byte-swapping functions for a machine with this byte
3753 =item Unknown "re" subpragma '%s' (known ones are: %s)
3755 You tried to use an unknown subpragma of the "re" pragma.
3757 =item Unknown switch condition (?(%.2s in regex;
3759 marked by <-- HERE in m/%s/
3761 (F) The condition part of a (?(condition)if-clause|else-clause) construct
3762 is not known. The condition may be lookahead or lookbehind (the condition
3763 is true if the lookahead or lookbehind is true), a (?{...}) construct (the
3764 condition is true if the code evaluates to a true value), or a number (the
3765 condition is true if the set of capturing parentheses named by the number
3768 The <-- HERE shows in the regular expression about where the problem was
3769 discovered. See L<perlre>.
3771 =item Unknown open() mode '%s'
3773 (F) The second argument of 3-argument open() is not among the list
3774 of valid modes: C<< < >>, C<< > >>, C<<< >> >>>, C<< +< >>,
3775 C<< +> >>, C<<< +>> >>>, C<-|>, C<|->, C<< <& >>, C<< >& >>.
3777 =item Unknown process %x sent message to prime_env_iter: %s
3779 (P) An error peculiar to VMS. Perl was reading values for %ENV before
3780 iterating over it, and someone else stuck a message in the stream of
3781 data Perl expected. Someone's very confused, or perhaps trying to
3782 subvert Perl's population of %ENV for nefarious purposes.
3784 =item Unknown warnings category '%s'
3786 (F) An error issued by the C<warnings> pragma. You specified a warnings
3787 category that is unknown to perl at this point.
3789 Note that if you want to enable a warnings category registered by a module
3790 (e.g. C<use warnings 'File::Find'>), you must have imported this module
3793 =item unmatched [ in regex; marked by <-- HERE in m/%s/
3795 (F) The brackets around a character class must match. If you wish to
3796 include a closing bracket in a character class, backslash it or put it
3797 first. The <-- HERE shows in the regular expression about where the problem
3798 was discovered. See L<perlre>.
3800 =item unmatched ( in regex; marked by <-- HERE in m/%s/
3802 (F) Unbackslashed parentheses must always be balanced in regular
3803 expressions. If you're a vi user, the % key is valuable for finding the
3804 matching parenthesis. The <-- HERE shows in the regular expression about
3805 where the problem was discovered. See L<perlre>.
3807 =item Unmatched right %s bracket
3809 (F) The lexer counted more closing curly or square brackets than opening
3810 ones, so you're probably missing a matching opening bracket. As a
3811 general rule, you'll find the missing one (so to speak) near the place
3812 you were last editing.
3814 =item Unquoted string "%s" may clash with future reserved word
3816 (W reserved) You used a bareword that might someday be claimed as a
3817 reserved word. It's best to put such a word in quotes, or capitalize it
3818 somehow, or insert an underbar into it. You might also declare it as a
3821 =item Unrecognized character %s
3823 (F) The Perl parser has no idea what to do with the specified character
3824 in your Perl script (or eval). Perhaps you tried to run a compressed
3825 script, a binary program, or a directory as a Perl program.
3827 =item /%s/: Unrecognized escape \\%c in character class passed through
3829 (W regexp) You used a backslash-character combination which is not
3830 recognized by Perl inside character classes. The character was
3831 understood literally.
3833 =item Unrecognized escape \\%c passed through in regex;
3835 marked by <-- HERE in m/%s/
3837 (W regexp) You used a backslash-character combination which is not
3838 recognized by Perl. This combination appears in an interpolated variable or
3839 a C<'>-delimited regular expression. The character was understood
3840 literally. The <-- HERE shows in the regular expression about where the
3841 escape was discovered.
3843 =item Unrecognized escape \\%c passed through
3845 (W misc) You used a backslash-character combination which is not
3848 =item Unrecognized signal name "%s"
3850 (F) You specified a signal name to the kill() function that was not
3851 recognized. Say C<kill -l> in your shell to see the valid signal names
3854 =item Unrecognized switch: -%s (-h will show valid options)
3856 (F) You specified an illegal option to Perl. Don't do that. (If you
3857 think you didn't do that, check the #! line to see if it's supplying the
3858 bad switch on your behalf.)
3860 =item Unsuccessful %s on filename containing newline
3862 (W newline) A file operation was attempted on a filename, and that
3863 operation failed, PROBABLY because the filename contained a newline,
3864 PROBABLY because you forgot to chomp() it off. See L<perlfunc/chomp>.
3866 =item Unsupported directory function "%s" called
3868 (F) Your machine doesn't support opendir() and readdir().
3870 =item Unsupported function %s
3872 (F) This machine doesn't implement the indicated function, apparently.
3873 At least, Configure doesn't think so.
3875 =item Unsupported function fork
3877 (F) Your version of executable does not support forking.
3879 Note that under some systems, like OS/2, there may be different flavors
3880 of Perl executables, some of which may support fork, some not. Try
3881 changing the name you call Perl by to C<perl_>, C<perl__>, and so on.
3883 =item Unsupported script encoding
3885 (F) Your program file begins with a Unicode Byte Order Mark (BOM) which
3886 declares it to be in a Unicode encoding that Perl cannot yet read.
3888 =item Unsupported socket function "%s" called
3890 (F) Your machine doesn't support the Berkeley socket mechanism, or at
3891 least that's what Configure thought.
3893 =item Unterminated attribute list
3895 (F) The lexer found something other than a simple identifier at the
3896 start of an attribute, and it wasn't a semicolon or the start of a
3897 block. Perhaps you terminated the parameter list of the previous
3898 attribute too soon. See L<attributes>.
3900 =item Unterminated attribute parameter in attribute list
3902 (F) The lexer saw an opening (left) parenthesis character while parsing
3903 an attribute list, but the matching closing (right) parenthesis
3904 character was not found. You may need to add (or remove) a backslash
3905 character to get your parentheses to balance. See L<attributes>.
3907 =item Unterminated compressed integer
3909 (F) An argument to unpack("w",...) was incompatible with the BER
3910 compressed integer format and could not be converted to an integer.
3911 See L<perlfunc/pack>.
3913 =item Unterminated <> operator
3915 (F) The lexer saw a left angle bracket in a place where it was expecting
3916 a term, so it's looking for the corresponding right angle bracket, and
3917 not finding it. Chances are you left some needed parentheses out
3918 earlier in the line, and you really meant a "less than".
3920 =item untie attempted while %d inner references still exist
3922 (W untie) A copy of the object returned from C<tie> (or C<tied>) was
3923 still valid when C<untie> was called.
3925 =item Useless (?%s) - use /%s modifier in regex;
3927 marked by <-- HERE in m/%s/
3929 (W regexp) You have used an internal modifier such as (?o) that has no
3930 meaning unless applied to the entire regexp:
3932 if ($string =~ /(?o)$pattern/) { ... }
3936 if ($string =~ /$pattern/o) { ... }
3938 The <-- HERE shows in the regular expression about
3939 where the problem was discovered. See L<perlre>.
3941 =item Useless (?-%s) - don't use /%s modifier in regex;
3943 marked by <-- HERE in m/%s/
3945 (W regexp) You have used an internal modifier such as (?-o) that has no
3946 meaning unless removed from the entire regexp:
3948 if ($string =~ /(?-o)$pattern/o) { ... }
3952 if ($string =~ /$pattern/) { ... }
3954 The <-- HERE shows in the regular expression about
3955 where the problem was discovered. See L<perlre>.
3957 =item Useless use of %s in void context
3959 (W void) You did something without a side effect in a context that does
3960 nothing with the return value, such as a statement that doesn't return a
3961 value from a block, or the left side of a scalar comma operator. Very
3962 often this points not to stupidity on your part, but a failure of Perl
3963 to parse your program the way you thought it would. For example, you'd
3964 get this if you mixed up your C precedence with Python precedence and
3969 when you meant to say
3971 ($one, $two) = (1, 2);
3973 Another common error is to use ordinary parentheses to construct a list
3974 reference when you should be using square or curly brackets, for
3979 when you should have said
3983 The square brackets explicitly turn a list value into a scalar value,
3984 while parentheses do not. So when a parenthesized list is evaluated in
3985 a scalar context, the comma is treated like C's comma operator, which
3986 throws away the left argument, which is not what you want. See
3987 L<perlref> for more on this.
3989 This warning will not be issued for numerical constants equal to 0 or 1
3990 since they are often used in statements like
3992 1 while sub_with_side_effects() ;
3994 String constants that would normally evaluate to 0 or 1 are warned
3997 =item Useless use of "re" pragma
3999 (W) You did C<use re;> without any arguments. That isn't very useful.
4001 =item Useless use of sort in scalar context
4003 (W void) You used sort in scalar context, as in :
4007 This is not very useful, and perl currently optimizes this away.
4009 =item Useless use of %s with no values
4011 (W syntax) You used the push() or unshift() function with no arguments
4012 apart from the array, like C<push(@x)> or C<unshift(@foo)>. That won't
4013 usually have any effect on the array, so is completely useless. It's
4014 possible in principle that push(@tied_array) could have some effect
4015 if the array is tied to a class which implements a PUSH method. If so,
4016 you can write it as C<push(@tied_array,())> to avoid this warning.
4018 =item "use" not allowed in expression
4020 (F) The "use" keyword is recognized and executed at compile time, and
4021 returns no useful value. See L<perlmod>.
4023 =item Use of bare << to mean <<"" is deprecated
4025 (D deprecated) You are now encouraged to use the explicitly quoted form
4026 if you wish to use an empty line as the terminator of the here-document.
4028 =item Use of /c modifier is meaningless in s///
4030 (W regexp) You used the /c modifier in a substitution. The /c
4031 modifier is not presently meaningful in substitutions.
4033 =item Use of /c modifier is meaningless without /g
4035 (W regexp) You used the /c modifier with a regex operand, but didn't
4036 use the /g modifier. Currently, /c is meaningful only when /g is
4037 used. (This may change in the future.)
4039 =item Use of /g modifier is meaningless in split
4041 (W regexp) You used the /g modifier on the pattern for a C<split>
4042 operator. Since C<split> always tries to match the pattern
4043 repeatedly, the C</g> has no effect.
4045 =item Use of *glob{FILEHANDLE} is deprecated
4047 (D deprecated) You are now encouraged to use the shorter *glob{IO} form
4048 to access the filehandle slot within a typeglob.
4050 =item Use of chdir('') or chdir(undef) as chdir() deprecated
4052 (D deprecated) chdir() with no arguments is documented to change to
4053 $ENV{HOME} or $ENV{LOGDIR}. chdir(undef) and chdir('') share this
4054 behavior, but that has been deprecated. In future versions they
4057 Be careful to check that what you pass to chdir() is defined and not
4058 blank, else you might find yourself in your home directory.
4060 =item Use of implicit split to @_ is deprecated
4062 (D deprecated) It makes a lot of work for the compiler when you clobber
4063 a subroutine's argument list, so it's better if you assign the results
4064 of a split() explicitly to an array (or list).
4066 =item Use of inherited AUTOLOAD for non-method %s() is deprecated
4068 (D deprecated) As an (ahem) accidental feature, C<AUTOLOAD> subroutines
4069 are looked up as methods (using the C<@ISA> hierarchy) even when the
4070 subroutines to be autoloaded were called as plain functions (e.g.
4071 C<Foo::bar()>), not as methods (e.g. C<< Foo->bar() >> or C<<
4074 This bug will be rectified in future by using method lookup only for
4075 methods' C<AUTOLOAD>s. However, there is a significant base of existing
4076 code that may be using the old behavior. So, as an interim step, Perl
4077 currently issues an optional warning when non-methods use inherited
4080 The simple rule is: Inheritance will not work when autoloading
4081 non-methods. The simple fix for old code is: In any module that used
4082 to depend on inheriting C<AUTOLOAD> for non-methods from a base class
4083 named C<BaseClass>, execute C<*AUTOLOAD = \&BaseClass::AUTOLOAD> during
4086 In code that currently says C<use AutoLoader; @ISA = qw(AutoLoader);>
4087 you should remove AutoLoader from @ISA and change C<use AutoLoader;> to
4088 C<use AutoLoader 'AUTOLOAD';>.
4090 =item Use of -l on filehandle %s
4092 (W io) A filehandle represents an opened file, and when you opened the file
4093 it already went past any symlink you are presumably trying to look for.
4094 The operation returned C<undef>. Use a filename instead.
4096 =item Use of "package" with no arguments is deprecated
4098 (D deprecated) You used the C<package> keyword without specifying a package
4099 name. So no namespace is current at all. Using this can cause many
4100 otherwise reasonable constructs to fail in baffling ways. C<use strict;>
4103 =item Use of %s in printf format not supported
4105 (F) You attempted to use a feature of printf that is accessible from
4106 only C. This usually means there's a better way to do it in Perl.
4108 =item Use of $* is deprecated
4110 (D deprecated) This variable magically turned on multi-line pattern
4111 matching, both for you and for any luckless subroutine that you happen
4112 to call. You should use the new C<//m> and C<//s> modifiers now to do
4113 that without the dangerous action-at-a-distance effects of C<$*>.
4115 =item Use of %s is deprecated
4117 (D deprecated) The construct indicated is no longer recommended for use,
4118 generally because there's a better way to do it, and also because the
4119 old way has bad side effects.
4121 =item Use of $# is deprecated
4123 (D deprecated) This was an ill-advised attempt to emulate a poorly
4124 defined B<awk> feature. Use an explicit printf() or sprintf() instead.
4126 =item Use of reference "%s" as array index
4128 (W) You tried to use a reference as an array index; this probably
4129 isn't what you mean, because references in numerical context tend
4130 to be huge numbers, and so usually indicates programmer error.
4132 If you really do mean it, explicitly numify your reference, like so:
4133 C<$array[0+$ref]>. This warning is not given for overloaded objects,
4134 either, because you can overload the numification and stringification
4135 operators and then you assumedly know what you are doing.
4137 =item Use of reserved word "%s" is deprecated
4139 (D deprecated) The indicated bareword is a reserved word. Future
4140 versions of perl may use it as a keyword, so you're better off either
4141 explicitly quoting the word in a manner appropriate for its context of
4142 use, or using a different name altogether. The warning can be
4143 suppressed for subroutine names by either adding a C<&> prefix, or using
4144 a package qualifier, e.g. C<&our()>, or C<Foo::our()>.
4146 =item Use of tainted arguments in %s is deprecated
4148 (W taint) You have supplied C<system()> or C<exec()> with multiple
4149 arguments and at least one of them is tainted. This used to be allowed
4150 but will become a fatal error in a future version of perl. Untaint your
4151 arguments. See L<perlsec>.
4153 =item Use of uninitialized value%s
4155 (W uninitialized) An undefined value was used as if it were already
4156 defined. It was interpreted as a "" or a 0, but maybe it was a mistake.
4157 To suppress this warning assign a defined value to your variables.
4159 To help you figure out what was undefined, perl tells you what operation
4160 you used the undefined value in. Note, however, that perl optimizes your
4161 program and the operation displayed in the warning may not necessarily
4162 appear literally in your program. For example, C<"that $foo"> is
4163 usually optimized into C<"that " . $foo>, and the warning will refer to
4164 the C<concatenation (.)> operator, even though there is no C<.> in your
4167 =item Using a hash as a reference is deprecated
4169 (D deprecated) You tried to use a hash as a reference, as in
4170 C<< %foo->{"bar"} >> or C<< %$ref->{"hello"} >>. Versions of perl <= 5.6.1
4171 used to allow this syntax, but shouldn't have. It is now deprecated, and will
4172 be removed in a future version.
4174 =item Using an array as a reference is deprecated
4176 (D deprecated) You tried to use an array as a reference, as in
4177 C<< @foo->[23] >> or C<< @$ref->[99] >>. Versions of perl <= 5.6.1 used to
4178 allow this syntax, but shouldn't have. It is now deprecated, and will be
4179 removed in a future version.
4181 =item UTF-16 surrogate %s
4183 (W utf8) You tried to generate half of an UTF-16 surrogate by
4184 requesting a Unicode character between the code points 0xD800 and
4185 0xDFFF (inclusive). That range is reserved exclusively for the use of
4186 UTF-16 encoding (by having two 16-bit UCS-2 characters); but Perl
4187 encodes its characters in UTF-8, so what you got is a very illegal
4188 character. If you really know what you are doing you can turn off
4189 this warning by C<no warnings 'utf8';>.
4191 =item Value of %s can be "0"; test with defined()
4193 (W misc) In a conditional expression, you used <HANDLE>, <*> (glob),
4194 C<each()>, or C<readdir()> as a boolean value. Each of these constructs
4195 can return a value of "0"; that would make the conditional expression
4196 false, which is probably not what you intended. When using these
4197 constructs in conditional expressions, test their values with the
4198 C<defined> operator.
4200 =item Value of CLI symbol "%s" too long
4202 (W misc) A warning peculiar to VMS. Perl tried to read the value of an
4203 %ENV element from a CLI symbol table, and found a resultant string
4204 longer than 1024 characters. The return value has been truncated to
4207 =item Variable "%s" is not imported%s
4209 (F) While "use strict" in effect, you referred to a global variable that
4210 you apparently thought was imported from another module, because
4211 something else of the same name (usually a subroutine) is exported by
4212 that module. It usually means you put the wrong funny character on the
4213 front of your variable.
4215 =item "%s" variable %s masks earlier declaration in same %s
4217 (W misc) A "my" or "our" variable has been redeclared in the current
4218 scope or statement, effectively eliminating all access to the previous
4219 instance. This is almost always a typographical error. Note that the
4220 earlier variable will still exist until the end of the scope or until
4221 all closure referents to it are destroyed.
4223 =item Variable "%s" may be unavailable
4225 (W closure) An inner (nested) I<anonymous> subroutine is inside a
4226 I<named> subroutine, and outside that is another subroutine; and the
4227 anonymous (innermost) subroutine is referencing a lexical variable
4228 defined in the outermost subroutine. For example:
4230 sub outermost { my $a; sub middle { sub { $a } } }
4232 If the anonymous subroutine is called or referenced (directly or
4233 indirectly) from the outermost subroutine, it will share the variable as
4234 you would expect. But if the anonymous subroutine is called or
4235 referenced when the outermost subroutine is not active, it will see the
4236 value of the shared variable as it was before and during the *first*
4237 call to the outermost subroutine, which is probably not what you want.
4239 In these circumstances, it is usually best to make the middle subroutine
4240 anonymous, using the C<sub {}> syntax. Perl has specific support for
4241 shared variables in nested anonymous subroutines; a named subroutine in
4242 between interferes with this feature.
4244 =item Variable syntax
4246 (A) You've accidentally run your script through B<csh> instead
4247 of Perl. Check the #! line, or manually feed your script into
4250 =item Variable "%s" will not stay shared
4252 (W closure) An inner (nested) I<named> subroutine is referencing a
4253 lexical variable defined in an outer subroutine.
4255 When the inner subroutine is called, it will probably see the value of
4256 the outer subroutine's variable as it was before and during the *first*
4257 call to the outer subroutine; in this case, after the first call to the
4258 outer subroutine is complete, the inner and outer subroutines will no
4259 longer share a common value for the variable. In other words, the
4260 variable will no longer be shared.
4262 Furthermore, if the outer subroutine is anonymous and references a
4263 lexical variable outside itself, then the outer and inner subroutines
4264 will I<never> share the given variable.
4266 This problem can usually be solved by making the inner subroutine
4267 anonymous, using the C<sub {}> syntax. When inner anonymous subs that
4268 reference variables in outer subroutines are called or referenced, they
4269 are automatically rebound to the current values of such variables.
4271 =item Variable length lookbehind not implemented in regex;
4273 marked by <-- HERE in m/%s/
4275 (F) Lookbehind is allowed only for subexpressions whose length is fixed and
4276 known at compile time. The <-- HERE shows in the regular expression about
4277 where the problem was discovered. See L<perlre>.
4279 =item Version number must be a constant number
4281 (P) The attempt to translate a C<use Module n.n LIST> statement into
4282 its equivalent C<BEGIN> block found an internal inconsistency with
4285 =item v-string in use/require is non-portable
4287 (W) The use of v-strings is non-portable to older, pre-5.6, Perls.
4288 If you want your scripts to be backward portable, use the floating
4289 point version number: for example, instead of C<use 5.6.1> say
4290 C<use 5.006_001>. This of course won't help: the older Perls
4291 won't suddenly start understanding newer features, but at least
4292 they will show a sensible error message indicating the required
4295 =item Warning: something's wrong
4297 (W) You passed warn() an empty string (the equivalent of C<warn "">) or
4298 you called it with no args and C<$_> was empty.
4300 =item Warning: unable to close filehandle %s properly
4302 (S) The implicit close() done by an open() got an error indication on
4303 the close(). This usually indicates your file system ran out of disk
4306 =item Warning: Use of "%s" without parentheses is ambiguous
4308 (S ambiguous) You wrote a unary operator followed by something that
4309 looks like a binary operator that could also have been interpreted as a
4310 term or unary operator. For instance, if you know that the rand
4311 function has a default argument of 1.0, and you write
4315 you may THINK you wrote the same thing as
4319 but in actual fact, you got
4323 So put in parentheses to say what you really mean.
4325 =item Wide character in %s
4327 (W utf8) Perl met a wide character (>255) when it wasn't expecting
4328 one. This warning is by default on for I/O (like print) but can be
4329 turned off by C<no warnings 'utf8';>. You are supposed to explicitly
4330 mark the filehandle with an encoding, see L<open> and L<perlfunc/binmode>.
4332 =item write() on closed filehandle %s
4334 (W closed) The filehandle you're writing to got itself closed sometime
4335 before now. Check your control flow.
4337 =item X outside of string
4339 (F) You had a pack template that specified a relative position before
4340 the beginning of the string being unpacked. See L<perlfunc/pack>.
4342 =item x outside of string
4344 (F) You had a pack template that specified a relative position after
4345 the end of the string being unpacked. See L<perlfunc/pack>.
4347 =item Xsub "%s" called in sort
4349 (F) The use of an external subroutine as a sort comparison is not yet
4352 =item Xsub called in sort
4354 (F) The use of an external subroutine as a sort comparison is not yet
4357 =item YOU HAVEN'T DISABLED SET-ID SCRIPTS IN THE KERNEL YET!
4359 (F) And you probably never will, because you probably don't have the
4360 sources to your kernel, and your vendor probably doesn't give a rip
4361 about what you want. Your best bet is to put a setuid C wrapper around
4364 =item You need to quote "%s"
4366 (W syntax) You assigned a bareword as a signal handler name.
4367 Unfortunately, you already have a subroutine of that name declared,
4368 which means that Perl 5 will try to call the subroutine when the
4369 assignment is executed, which is probably not what you want. (If it IS
4370 what you want, put an & in front.)