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 the 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 Badly placed ()'s
323 (A) You've accidentally run your script through B<csh> instead
324 of Perl. Check the #! line, or manually feed your script into
327 =item Bad name after %s::
329 (F) You started to name a symbol by using a package prefix, and then
330 didn't finish the symbol. In particular, you can't interpolate outside
339 $sym = "mypack::$var";
341 =item Bad realloc() ignored
343 (S malloc) An internal routine called realloc() on something that had
344 never been malloc()ed in the first place. Mandatory, but can be disabled
345 by setting environment variable C<PERL_BADFREE> to 1.
347 =item Bad symbol for array
349 (P) An internal request asked to add an array entry to something that
350 wasn't a symbol table entry.
352 =item Bad symbol for filehandle
354 (P) An internal request asked to add a filehandle entry to something
355 that wasn't a symbol table entry.
357 =item Bad symbol for hash
359 (P) An internal request asked to add a hash entry to something that
360 wasn't a symbol table entry.
362 =item Bareword found in conditional
364 (W bareword) The compiler found a bareword where it expected a
365 conditional, which often indicates that an || or && was parsed as part
366 of the last argument of the previous construct, for example:
370 It may also indicate a misspelled constant that has been interpreted as
373 use constant TYPO => 1;
374 if (TYOP) { print "foo" }
376 The C<strict> pragma is useful in avoiding such errors.
378 =item Bareword "%s" not allowed while "strict subs" in use
380 (F) With "strict subs" in use, a bareword is only allowed as a
381 subroutine identifier, in curly brackets or to the left of the "=>"
382 symbol. Perhaps you need to predeclare a subroutine?
384 =item Bareword "%s" refers to nonexistent package
386 (W bareword) You used a qualified bareword of the form C<Foo::>, but the
387 compiler saw no other uses of that namespace before that point. Perhaps
388 you need to predeclare a package?
390 =item BEGIN failed--compilation aborted
392 (F) An untrapped exception was raised while executing a BEGIN
393 subroutine. Compilation stops immediately and the interpreter is
396 =item BEGIN not safe after errors--compilation aborted
398 (F) Perl found a C<BEGIN {}> subroutine (or a C<use> directive, which
399 implies a C<BEGIN {}>) after one or more compilation errors had already
400 occurred. Since the intended environment for the C<BEGIN {}> could not
401 be guaranteed (due to the errors), and since subsequent code likely
402 depends on its correct operation, Perl just gave up.
404 =item \1 better written as $1
406 (W syntax) Outside of patterns, backreferences live on as variables.
407 The use of backslashes is grandfathered on the right-hand side of a
408 substitution, but stylistically it's better to use the variable form
409 because other Perl programmers will expect it, and it works better if
410 there are more than 9 backreferences.
412 =item Binary number > 0b11111111111111111111111111111111 non-portable
414 (W portable) The binary number you specified is larger than 2**32-1
415 (4294967295) and therefore non-portable between systems. See
416 L<perlport> for more on portability concerns.
418 =item bind() on closed socket %s
420 (W closed) You tried to do a bind on a closed socket. Did you forget to
421 check the return value of your socket() call? See L<perlfunc/bind>.
423 =item binmode() on closed filehandle %s
425 (W unopened) You tried binmode() on a filehandle that was never opened.
426 Check you control flow and number of arguments.
428 =item Bit vector size > 32 non-portable
430 (W portable) Using bit vector sizes larger than 32 is non-portable.
432 =item Bizarre copy of %s in %s
434 (P) Perl detected an attempt to copy an internal value that is not
437 =item B<-P> not allowed for setuid/setgid script
439 (F) The script would have to be opened by the C preprocessor by name,
440 which provides a race condition that breaks security.
442 =item Buffer overflow in prime_env_iter: %s
444 (W internal) A warning peculiar to VMS. While Perl was preparing to
445 iterate over %ENV, it encountered a logical name or symbol definition
446 which was too long, so it was truncated to the string shown.
448 =item Callback called exit
450 (F) A subroutine invoked from an external package via call_sv()
451 exited by calling exit.
453 =item %s() called too early to check prototype
455 (W prototype) You've called a function that has a prototype before the
456 parser saw a definition or declaration for it, and Perl could not check
457 that the call conforms to the prototype. You need to either add an
458 early prototype declaration for the subroutine in question, or move the
459 subroutine definition ahead of the call to get proper prototype
460 checking. Alternatively, if you are certain that you're calling the
461 function correctly, you may put an ampersand before the name to avoid
462 the warning. See L<perlsub>.
464 =item / cannot take a count
466 (F) You had an unpack template indicating a counted-length string, but
467 you have also specified an explicit size for the string. See
470 =item Can't bless non-reference value
472 (F) Only hard references may be blessed. This is how Perl "enforces"
473 encapsulation of objects. See L<perlobj>.
475 =item Can't call method "%s" in empty package "%s"
477 (F) You called a method correctly, and it correctly indicated a package
478 functioning as a class, but that package doesn't have ANYTHING defined
479 in it, let alone methods. See L<perlobj>.
481 =item Can't call method "%s" on an undefined value
483 (F) You used the syntax of a method call, but the slot filled by the
484 object reference or package name contains an undefined value. Something
485 like this will reproduce the error:
488 process $BADREF 1,2,3;
489 $BADREF->process(1,2,3);
491 =item Can't call method "%s" on unblessed reference
493 (F) A method call must know in what package it's supposed to run. It
494 ordinarily finds this out from the object reference you supply, but you
495 didn't supply an object reference in this case. A reference isn't an
496 object reference until it has been blessed. See L<perlobj>.
498 =item Can't call method "%s" without a package or object reference
500 (F) You used the syntax of a method call, but the slot filled by the
501 object reference or package name contains an expression that returns a
502 defined value which is neither an object reference nor a package name.
503 Something like this will reproduce the error:
506 process $BADREF 1,2,3;
507 $BADREF->process(1,2,3);
509 =item Can't chdir to %s
511 (F) You called C<perl -x/foo/bar>, but C</foo/bar> is not a directory
512 that you can chdir to, possibly because it doesn't exist.
514 =item Can't check filesystem of script "%s" for nosuid
516 (P) For some reason you can't check the filesystem of the script for
519 =item Can't coerce array into hash
521 (F) You used an array where a hash was expected, but the array has no
522 information on how to map from keys to array indices. You can do that
523 only with arrays that have a hash reference at index 0.
525 =item Can't coerce %s to integer in %s
527 (F) Certain types of SVs, in particular real symbol table entries
528 (typeglobs), can't be forced to stop being what they are. So you can't
538 but then $foo no longer contains a glob.
540 =item Can't coerce %s to number in %s
542 (F) Certain types of SVs, in particular real symbol table entries
543 (typeglobs), can't be forced to stop being what they are.
545 =item Can't coerce %s to string in %s
547 (F) Certain types of SVs, in particular real symbol table entries
548 (typeglobs), can't be forced to stop being what they are.
550 =item Can't create pipe mailbox
552 (P) An error peculiar to VMS. The process is suffering from exhausted
553 quotas or other plumbing problems.
555 =item Can't declare class for non-scalar %s in "%s"
557 (F) Currently, only scalar variables can be declared with a specific
558 class qualifier in a "my" or "our" declaration. The semantics may be
559 extended for other types of variables in future.
561 =item Can't declare %s in "%s"
563 (F) Only scalar, array, and hash variables may be declared as "my" or
564 "our" variables. They must have ordinary identifiers as names.
566 =item Can't do inplace edit: %s is not a regular file
568 (S inplace) You tried to use the B<-i> switch on a special file, such as
569 a file in /dev, or a FIFO. The file was ignored.
571 =item Can't do inplace edit on %s: %s
573 (S inplace) The creation of the new file failed for the indicated
576 =item Can't do inplace edit without backup
578 (F) You're on a system such as MS-DOS that gets confused if you try
579 reading from a deleted (but still opened) file. You have to say
580 C<-i.bak>, or some such.
582 =item Can't do inplace edit: %s would not be unique
584 (S inplace) Your filesystem does not support filenames longer than 14
585 characters and Perl was unable to create a unique filename during
586 inplace editing with the B<-i> switch. The file was ignored.
588 =item Can't do {n,m} with n > m in regex; marked by <-- HERE in m/%s/
590 (F) Minima must be less than or equal to maxima. If you really want your
591 regexp to match something 0 times, just put {0}. The <-- HERE shows in the
592 regular expression about where the problem was discovered. See L<perlre>.
594 =item Can't do setegid!
596 (P) The setegid() call failed for some reason in the setuid emulator of
599 =item Can't do seteuid!
601 (P) The setuid emulator of suidperl failed for some reason.
603 =item Can't do setuid
605 (F) This typically means that ordinary perl tried to exec suidperl to do
606 setuid emulation, but couldn't exec it. It looks for a name of the form
607 sperl5.000 in the same directory that the perl executable resides under
608 the name perl5.000, typically /usr/local/bin on Unix machines. If the
609 file is there, check the execute permissions. If it isn't, ask your
610 sysadmin why he and/or she removed it.
612 =item Can't do waitpid with flags
614 (F) This machine doesn't have either waitpid() or wait4(), so only
615 waitpid() without flags is emulated.
617 =item Can't emulate -%s on #! line
619 (F) The #! line specifies a switch that doesn't make sense at this
620 point. For example, it'd be kind of silly to put a B<-x> on the #!
623 =item Can't exec "%s": %s
625 (W exec) A system(), exec(), or piped open call could not execute the
626 named program for the indicated reason. Typical reasons include: the
627 permissions were wrong on the file, the file wasn't found in
628 C<$ENV{PATH}>, the executable in question was compiled for another
629 architecture, or the #! line in a script points to an interpreter that
630 can't be run for similar reasons. (Or maybe your system doesn't support
635 (F) Perl was trying to execute the indicated program for you because
636 that's what the #! line said. If that's not what you wanted, you may
637 need to mention "perl" on the #! line somewhere.
639 =item Can't execute %s
641 (F) You used the B<-S> switch, but the copies of the script to execute
642 found in the PATH did not have correct permissions.
644 =item Can't find an opnumber for "%s"
646 (F) A string of a form C<CORE::word> was given to prototype(), but there
647 is no builtin with the name C<word>.
649 =item Can't find %s character property "%s"
651 (F) You used C<\p{}> or C<\P{}> but the character property by that name
652 could not be found. Maybe you misspelled the name of the property
653 (remember that the names of character properties consist only of
654 alphanumeric characters), or maybe you forgot the C<Is> or C<In> prefix?
656 =item Can't find label %s
658 (F) You said to goto a label that isn't mentioned anywhere that it's
659 possible for us to go to. See L<perlfunc/goto>.
661 =item Can't find %s on PATH
663 (F) You used the B<-S> switch, but the script to execute could not be
666 =item Can't find %s on PATH, '.' not in PATH
668 (F) You used the B<-S> switch, but the script to execute could not be
669 found in the PATH, or at least not with the correct permissions. The
670 script exists in the current directory, but PATH prohibits running it.
672 =item Can't find string terminator %s anywhere before EOF
674 (F) Perl strings can stretch over multiple lines. This message means
675 that the closing delimiter was omitted. Because bracketed quotes count
676 nesting levels, the following is missing its final parenthesis:
678 print q(The character '(' starts a side comment.);
680 If you're getting this error from a here-document, you may have included
681 unseen whitespace before or after your closing tag. A good programmer's
682 editor will have a way to help you find these characters.
684 =item Can't find %s property definition %s
686 (F) You may have tried to use C<\p> which means a Unicode property (for
687 example C<\p{Lu}> is all uppercase letters). If you did mean to use a
688 Unicode property, see L<perlunicode> for the list of known properties.
689 If you didn't mean to use a Unicode property, escape the C<\p>, either
690 by C<\\p> (just the C<\p>) or by C<\Q\p> (the rest of the string, until
695 (F) A fatal error occurred while trying to fork while opening a
698 =item Can't get filespec - stale stat buffer?
700 (S) A warning peculiar to VMS. This arises because of the difference
701 between access checks under VMS and under the Unix model Perl assumes.
702 Under VMS, access checks are done by filename, rather than by bits in
703 the stat buffer, so that ACLs and other protections can be taken into
704 account. Unfortunately, Perl assumes that the stat buffer contains all
705 the necessary information, and passes it, instead of the filespec, to
706 the access checking routine. It will try to retrieve the filespec using
707 the device name and FID present in the stat buffer, but this works only
708 if you haven't made a subsequent call to the CRTL stat() routine,
709 because the device name is overwritten with each call. If this warning
710 appears, the name lookup failed, and the access checking routine gave up
711 and returned FALSE, just to be conservative. (Note: The access checking
712 routine knows about the Perl C<stat> operator and file tests, so you
713 shouldn't ever see this warning in response to a Perl command; it arises
714 only if some internal code takes stat buffers lightly.)
716 =item Can't get pipe mailbox device name
718 (P) An error peculiar to VMS. After creating a mailbox to act as a
719 pipe, Perl can't retrieve its name for later use.
721 =item Can't get SYSGEN parameter value for MAXBUF
723 (P) An error peculiar to VMS. Perl asked $GETSYI how big you want your
724 mailbox buffers to be, and didn't get an answer.
726 =item Can't "goto" into the middle of a foreach loop
728 (F) A "goto" statement was executed to jump into the middle of a foreach
729 loop. You can't get there from here. See L<perlfunc/goto>.
731 =item Can't "goto" out of a pseudo block
733 (F) A "goto" statement was executed to jump out of what might look like
734 a block, except that it isn't a proper block. This usually occurs if
735 you tried to jump out of a sort() block or subroutine, which is a no-no.
736 See L<perlfunc/goto>.
738 =item Can't goto subroutine from an eval-string
740 (F) The "goto subroutine" call can't be used to jump out of an eval
741 "string". (You can use it to jump out of an eval {BLOCK}, but you
742 probably don't want to.)
744 =item Can't goto subroutine outside a subroutine
746 (F) The deeply magical "goto subroutine" call can only replace one
747 subroutine call for another. It can't manufacture one out of whole
748 cloth. In general you should be calling it out of only an AUTOLOAD
749 routine anyway. See L<perlfunc/goto>.
751 =item Can't ignore signal CHLD, forcing to default
753 (W signal) Perl has detected that it is being run with the SIGCHLD
754 signal (sometimes known as SIGCLD) disabled. Since disabling this
755 signal will interfere with proper determination of exit status of child
756 processes, Perl has reset the signal to its default value. This
757 situation typically indicates that the parent program under which Perl
758 may be running (e.g. cron) is being very careless.
760 =item Can't "last" outside a loop block
762 (F) A "last" statement was executed to break out of the current block,
763 except that there's this itty bitty problem called there isn't a current
764 block. Note that an "if" or "else" block doesn't count as a "loopish"
765 block, as doesn't a block given to sort(), map() or grep(). You can
766 usually double the curlies to get the same effect though, because the
767 inner curlies will be considered a block that loops once. See
770 =item Can't localize lexical variable %s
772 (F) You used local on a variable name that was previously declared as a
773 lexical variable using "my". This is not allowed. If you want to
774 localize a package variable of the same name, qualify it with the
777 =item Can't localize through a reference
779 (F) You said something like C<local $$ref>, which Perl can't currently
780 handle, because when it goes to restore the old value of whatever $ref
781 pointed to after the scope of the local() is finished, it can't be sure
782 that $ref will still be a reference.
784 =item Can't locate %s
786 (F) You said to C<do> (or C<require>, or C<use>) a file that couldn't be
787 found. Perl looks for the file in all the locations mentioned in @INC,
788 unless the file name included the full path to the file. Perhaps you
789 need to set the PERL5LIB or PERL5OPT environment variable to say where
790 the extra library is, or maybe the script needs to add the library name
791 to @INC. Or maybe you just misspelled the name of the file. See
792 L<perlfunc/require> and L<lib>.
794 =item Can't locate auto/%s.al in @INC
796 (F) A function (or method) was called in a package which allows
797 autoload, but there is no function to autoload. Most probable causes
798 are a misprint in a function/method name or a failure to C<AutoSplit>
799 the file, say, by doing C<make install>.
801 =item Can't locate object method "%s" via package "%s"
803 (F) You called a method correctly, and it correctly indicated a package
804 functioning as a class, but that package doesn't define that particular
805 method, nor does any of its base classes. See L<perlobj>.
807 =item Can't locate PerlIO%s
809 (F) You tried to use in open() a PerlIO layer that does not exist,
810 e.g. open(FH, ">:nosuchlayer", "somefile").
812 =item (perhaps you forgot to load "%s"?)
814 (F) This is an educated guess made in conjunction with the message
815 "Can't locate object method \"%s\" via package \"%s\"". It often means
816 that a method requires a package that has not been loaded.
818 =item Can't locate package %s for @%s::ISA
820 (W syntax) The @ISA array contained the name of another package that
821 doesn't seem to exist.
823 =item Can't make list assignment to \%ENV on this system
825 (F) List assignment to %ENV is not supported on some systems, notably
828 =item Can't modify %s in %s
830 (F) You aren't allowed to assign to the item indicated, or otherwise try
831 to change it, such as with an auto-increment.
833 =item Can't modify nonexistent substring
835 (P) The internal routine that does assignment to a substr() was handed
838 =item Can't modify non-lvalue subroutine call
840 (F) Subroutines meant to be used in lvalue context should be declared as
841 such, see L<perlsub/"Lvalue subroutines">.
843 =item Can't msgrcv to read-only var
845 (F) The target of a msgrcv must be modifiable to be used as a receive
848 =item Can't "next" outside a loop block
850 (F) A "next" statement was executed to reiterate the current block, but
851 there isn't a current block. Note that an "if" or "else" block doesn't
852 count as a "loopish" block, as doesn't a block given to sort(), map() or
853 grep(). You can usually double the curlies to get the same effect
854 though, because the inner curlies will be considered a block that loops
855 once. See L<perlfunc/next>.
857 =item Can't open %s: %s
859 (S inplace) The implicit opening of a file through use of the C<< <> >>
860 filehandle, either implicitly under the C<-n> or C<-p> command-line
861 switches, or explicitly, failed for the indicated reason. Usually this
862 is because you don't have read permission for a file which you named on
865 =item Can't open a reference
867 (W io) You tried to open a scalar reference for reading or writing,
868 using the 3-arg open() syntax :
872 but your version of perl is compiled without perlio, and this form of
873 open is not supported.
875 =item Can't open bidirectional pipe
877 (W pipe) You tried to say C<open(CMD, "|cmd|")>, which is not supported.
878 You can try any of several modules in the Perl library to do this, such
879 as IPC::Open2. Alternately, direct the pipe's output to a file using
880 ">", and then read it in under a different file handle.
882 =item Can't open error file %s as stderr
884 (F) An error peculiar to VMS. Perl does its own command line
885 redirection, and couldn't open the file specified after '2>' or '2>>' on
886 the command line for writing.
888 =item Can't open input file %s as stdin
890 (F) An error peculiar to VMS. Perl does its own command line
891 redirection, and couldn't open the file specified after '<' on the
892 command line for reading.
894 =item Can't open output file %s as stdout
896 (F) An error peculiar to VMS. Perl does its own command line
897 redirection, and couldn't open the file specified after '>' or '>>' on
898 the command line for writing.
900 =item Can't open output pipe (name: %s)
902 (P) An error peculiar to VMS. Perl does its own command line
903 redirection, and couldn't open the pipe into which to send data destined
906 =item Can't open perl script%s: %s
908 (F) The script you specified can't be opened for the indicated reason.
910 =item Can't read CRTL environ
912 (S) A warning peculiar to VMS. Perl tried to read an element of %ENV
913 from the CRTL's internal environment array and discovered the array was
914 missing. You need to figure out where your CRTL misplaced its environ
915 or define F<PERL_ENV_TABLES> (see L<perlvms>) so that environ is not
918 =item Can't redefine active sort subroutine %s
920 (F) Perl optimizes the internal handling of sort subroutines and keeps
921 pointers into them. You tried to redefine one such sort subroutine when
922 it was currently active, which is not allowed. If you really want to do
923 this, you should write C<sort { &func } @x> instead of C<sort func @x>.
925 =item Can't "redo" outside a loop block
927 (F) A "redo" statement was executed to restart the current block, but
928 there isn't a current block. Note that an "if" or "else" block doesn't
929 count as a "loopish" block, as doesn't a block given to sort(), map()
930 or grep(). You can usually double the curlies to get the same effect
931 though, because the inner curlies will be considered a block that
932 loops once. See L<perlfunc/redo>.
934 =item Can't remove %s: %s, skipping file
936 (S inplace) You requested an inplace edit without creating a backup
937 file. Perl was unable to remove the original file to replace it with
938 the modified file. The file was left unmodified.
940 =item Can't rename %s to %s: %s, skipping file
942 (S inplace) The rename done by the B<-i> switch failed for some reason,
943 probably because you don't have write permission to the directory.
945 =item Can't reopen input pipe (name: %s) in binary mode
947 (P) An error peculiar to VMS. Perl thought stdin was a pipe, and tried
948 to reopen it to accept binary data. Alas, it failed.
950 =item Can't resolve method `%s' overloading `%s' in package `%s'
952 (F|P) Error resolving overloading specified by a method name (as opposed
953 to a subroutine reference): no such method callable via the package. If
954 method name is C<???>, this is an internal error.
956 =item Can't reswap uid and euid
958 (P) The setreuid() call failed for some reason in the setuid emulator of
961 =item Can't return %s from lvalue subroutine
963 (F) Perl detected an attempt to return illegal lvalues (such as
964 temporary or readonly values) from a subroutine used as an lvalue. This
967 =item Can't return %s to lvalue scalar context
969 (F) You tried to return a complete array or hash from an lvalue subroutine,
970 but you called the subroutine in a way that made Perl think you meant
971 to return only one value. You probably meant to write parentheses around
972 the call to the subroutine, which tell Perl that the call should be in
975 =item Can't return outside a subroutine
977 (F) The return statement was executed in mainline code, that is, where
978 there was no subroutine call to return out of. See L<perlsub>.
980 =item Can't stat script "%s"
982 (P) For some reason you can't fstat() the script even though you have it
983 open already. Bizarre.
985 =item Can't swap uid and euid
987 (P) The setreuid() call failed for some reason in the setuid emulator of
990 =item Can't take log of %g
992 (F) For ordinary real numbers, you can't take the logarithm of a
993 negative number or zero. There's a Math::Complex package that comes
994 standard with Perl, though, if you really want to do that for the
997 =item Can't take sqrt of %g
999 (F) For ordinary real numbers, you can't take the square root of a
1000 negative number. There's a Math::Complex package that comes standard
1001 with Perl, though, if you really want to do that.
1003 =item Can't undef active subroutine
1005 (F) You can't undefine a routine that's currently running. You can,
1006 however, redefine it while it's running, and you can even undef the
1007 redefined subroutine while the old routine is running. Go figure.
1011 (F) You tried to unshift an "unreal" array that can't be unshifted, such
1012 as the main Perl stack.
1014 =item Can't upgrade that kind of scalar
1016 (P) The internal sv_upgrade routine adds "members" to an SV, making it
1017 into a more specialized kind of SV. The top several SV types are so
1018 specialized, however, that they cannot be interconverted. This message
1019 indicates that such a conversion was attempted.
1021 =item Can't upgrade to undef
1023 (P) The undefined SV is the bottom of the totem pole, in the scheme of
1024 upgradability. Upgrading to undef indicates an error in the code
1027 =item Can't use an undefined value as %s reference
1029 (F) A value used as either a hard reference or a symbolic reference must
1030 be a defined value. This helps to delurk some insidious errors.
1032 =item Can't use anonymous symbol table for method lookup
1034 (P) The internal routine that does method lookup was handed a symbol
1035 table that doesn't have a name. Symbol tables can become anonymous
1036 for example by undefining stashes: C<undef %Some::Package::>.
1038 =item Can't use bareword ("%s") as %s ref while "strict refs" in use
1040 (F) Only hard references are allowed by "strict refs". Symbolic
1041 references are disallowed. See L<perlref>.
1043 =item Can't use %! because Errno.pm is not available
1045 (F) The first time the %! hash is used, perl automatically loads the
1046 Errno.pm module. The Errno module is expected to tie the %! hash to
1047 provide symbolic names for C<$!> errno values.
1049 =item Can't use %s for loop variable
1051 (F) Only a simple scalar variable may be used as a loop variable on a
1054 =item Can't use global %s in "my"
1056 (F) You tried to declare a magical variable as a lexical variable. This
1057 is not allowed, because the magic can be tied to only one location
1058 (namely the global variable) and it would be incredibly confusing to
1059 have variables in your program that looked like magical variables but
1062 =item Can't use "my %s" in sort comparison
1064 (F) The global variables $a and $b are reserved for sort comparisons.
1065 You mentioned $a or $b in the same line as the <=> or cmp operator,
1066 and the variable had earlier been declared as a lexical variable.
1067 Either qualify the sort variable with the package name, or rename the
1070 =item Can't use %s ref as %s ref
1072 (F) You've mixed up your reference types. You have to dereference a
1073 reference of the type needed. You can use the ref() function to
1074 test the type of the reference, if need be.
1076 =item Can't use string ("%s") as %s ref while "strict refs" in use
1078 (F) Only hard references are allowed by "strict refs". Symbolic
1079 references are disallowed. See L<perlref>.
1081 =item Can't use subscript on %s
1083 (F) The compiler tried to interpret a bracketed expression as a
1084 subscript. But to the left of the brackets was an expression that
1085 didn't look like an array reference, or anything else subscriptable.
1087 =item Can't use \%c to mean $%c in expression
1089 (W syntax) In an ordinary expression, backslash is a unary operator that
1090 creates a reference to its argument. The use of backslash to indicate a
1091 backreference to a matched substring is valid only as part of a regular
1092 expression pattern. Trying to do this in ordinary Perl code produces a
1093 value that prints out looking like SCALAR(0xdecaf). Use the $1 form
1096 =item Can't weaken a nonreference
1098 (F) You attempted to weaken something that was not a reference. Only
1099 references can be weakened.
1101 =item Can't x= to read-only value
1103 (F) You tried to repeat a constant value (often the undefined value)
1104 with an assignment operator, which implies modifying the value itself.
1105 Perhaps you need to copy the value to a temporary, and repeat that.
1107 =item Character in "C" format wrapped
1113 where $x is either less than 0 or more than 255; the C<"C"> format is
1114 only for encoding native operating system characters (ASCII, EBCDIC,
1115 and so on) and not for Unicode characters, so Perl behaved as if you meant
1119 If you actually want to pack Unicode codepoints, use the C<"U"> format
1122 =item Character in "c" format wrapped
1128 where $x is either less than -128 or more than 127; the C<"c"> format
1129 is only for encoding native operating system characters (ASCII, EBCDIC,
1130 and so on) and not for Unicode characters, so Perl behaved as if you meant
1132 pack("c", $x & 255);
1134 If you actually want to pack Unicode codepoints, use the C<"U"> format
1137 =item close() on unopened filehandle %s
1139 (W unopened) You tried to close a filehandle that was never opened.
1141 =item %s: Command not found
1143 (A) You've accidentally run your script through B<csh> instead of Perl.
1144 Check the #! line, or manually feed your script into Perl yourself.
1146 =item Compilation failed in require
1148 (F) Perl could not compile a file specified in a C<require> statement.
1149 Perl uses this generic message when none of the errors that it
1150 encountered were severe enough to halt compilation immediately.
1152 =item Complex regular subexpression recursion limit (%d) exceeded
1154 (W regexp) The regular expression engine uses recursion in complex
1155 situations where back-tracking is required. Recursion depth is limited
1156 to 32766, or perhaps less in architectures where the stack cannot grow
1157 arbitrarily. ("Simple" and "medium" situations are handled without
1158 recursion and are not subject to a limit.) Try shortening the string
1159 under examination; looping in Perl code (e.g. with C<while>) rather than
1160 in the regular expression engine; or rewriting the regular expression so
1161 that it is simpler or backtracks less. (See L<perlfaq2> for information
1162 on I<Mastering Regular Expressions>.)
1164 =item cond_broadcast() called on unlocked variable
1166 (W threads) Within a thread-enabled program, you tried to call
1167 cond_broadcast() on a variable which wasn't locked. The cond_broadcast()
1168 function is used to wake up another thread that is waiting in a
1169 cond_wait(). To ensure that the signal isn't sent before the other thread
1170 has a chance to enter the wait, it is usual for the signaling thread to
1171 first wait for a lock on variable. This lock attempt will only succeed
1172 after the other thread has entered cond_wait() and thus relinquished the
1176 =item cond_signal() called on unlocked variable
1178 (W threads) Within a thread-enabled program, you tried to call
1179 cond_signal() on a variable which wasn't locked. The cond_signal()
1180 function is used to wake up another thread that is waiting in a
1181 cond_wait(). To ensure that the signal isn't sent before the other thread
1182 has a chance to enter the wait, it is usual for the signaling thread to
1183 first wait for a lock on variable. This lock attempt will only succeed
1184 after the other thread has entered cond_wait() and thus relinquished the
1187 =item connect() on closed socket %s
1189 (W closed) You tried to do a connect on a closed socket. Did you forget
1190 to check the return value of your socket() call? See
1191 L<perlfunc/connect>.
1193 =item Constant(%s)%s: %s
1195 (F) The parser found inconsistencies either while attempting to define
1196 an overloaded constant, or when trying to find the character name
1197 specified in the C<\N{...}> escape. Perhaps you forgot to load the
1198 corresponding C<overload> or C<charnames> pragma? See L<charnames> and
1201 =item Constant is not %s reference
1203 (F) A constant value (perhaps declared using the C<use constant> pragma)
1204 is being dereferenced, but it amounts to the wrong type of reference.
1205 The message indicates the type of reference that was expected. This
1206 usually indicates a syntax error in dereferencing the constant value.
1207 See L<perlsub/"Constant Functions"> and L<constant>.
1209 =item Constant subroutine %s redefined
1211 (S) You redefined a subroutine which had previously been
1212 eligible for inlining. See L<perlsub/"Constant Functions"> for
1213 commentary and workarounds.
1215 =item Constant subroutine %s undefined
1217 (W misc) You undefined a subroutine which had previously been eligible
1218 for inlining. See L<perlsub/"Constant Functions"> for commentary and
1221 =item Copy method did not return a reference
1223 (F) The method which overloads "=" is buggy. See
1224 L<overload/Copy Constructor>.
1226 =item CORE::%s is not a keyword
1228 (F) The CORE:: namespace is reserved for Perl keywords.
1230 =item corrupted regexp pointers
1232 (P) The regular expression engine got confused by what the regular
1233 expression compiler gave it.
1235 =item corrupted regexp program
1237 (P) The regular expression engine got passed a regexp program without a
1240 =item Corrupt malloc ptr 0x%lx at 0x%lx
1242 (P) The malloc package that comes with Perl had an internal failure.
1244 =item C<-p> destination: %s
1246 (F) An error occurred during the implicit output invoked by the C<-p>
1247 command-line switch. (This output goes to STDOUT unless you've
1248 redirected it with select().)
1250 =item C<-T> and C<-B> not implemented on filehandles
1252 (F) Perl can't peek at the stdio buffer of filehandles when it doesn't
1253 know about your kind of stdio. You'll have to use a filename instead.
1255 =item Deep recursion on subroutine "%s"
1257 (W recursion) This subroutine has called itself (directly or indirectly)
1258 100 times more than it has returned. This probably indicates an
1259 infinite recursion, unless you're writing strange benchmark programs, in
1260 which case it indicates something else.
1262 =item defined(@array) is deprecated
1264 (D deprecated) defined() is not usually useful on arrays because it
1265 checks for an undefined I<scalar> value. If you want to see if the
1266 array is empty, just use C<if (@array) { # not empty }> for example.
1268 =item defined(%hash) is deprecated
1270 (D deprecated) defined() is not usually useful on hashes because it
1271 checks for an undefined I<scalar> value. If you want to see if the hash
1272 is empty, just use C<if (%hash) { # not empty }> for example.
1274 =item %s defines neither package nor VERSION--version check failed
1276 (F) You said something like "use Module 42" but in the Module file
1277 there are neither package declarations nor a C<$VERSION>.
1279 =item Delimiter for here document is too long
1281 (F) In a here document construct like C<<<FOO>, the label C<FOO> is too
1282 long for Perl to handle. You have to be seriously twisted to write code
1283 that triggers this error.
1285 =item Did not produce a valid header
1289 =item %s did not return a true value
1291 (F) A required (or used) file must return a true value to indicate that
1292 it compiled correctly and ran its initialization code correctly. It's
1293 traditional to end such a file with a "1;", though any true value would
1294 do. See L<perlfunc/require>.
1296 =item (Did you mean &%s instead?)
1298 (W) You probably referred to an imported subroutine &FOO as $FOO or some
1301 =item (Did you mean "local" instead of "our"?)
1303 (W misc) Remember that "our" does not localize the declared global
1304 variable. You have declared it again in the same lexical scope, which
1307 =item (Did you mean $ or @ instead of %?)
1309 (W) You probably said %hash{$key} when you meant $hash{$key} or
1310 @hash{@keys}. On the other hand, maybe you just meant %hash and got
1315 (F) You passed die() an empty string (the equivalent of C<die "">) or
1316 you called it with no args and both C<$@> and C<$_> were empty.
1318 =item Document contains no data
1322 =item %s does not define %s::VERSION--version check failed
1324 (F) You said something like "use Module 42" but the Module did not
1325 define a C<$VERSION.>
1327 =item Don't know how to handle magic of type '%s'
1329 (P) The internal handling of magical variables has been cursed.
1331 =item do_study: out of memory
1333 (P) This should have been caught by safemalloc() instead.
1335 =item (Do you need to predeclare %s?)
1337 (S) This is an educated guess made in conjunction with the message "%s
1338 found where operator expected". It often means a subroutine or module
1339 name is being referenced that hasn't been declared yet. This may be
1340 because of ordering problems in your file, or because of a missing
1341 "sub", "package", "require", or "use" statement. If you're referencing
1342 something that isn't defined yet, you don't actually have to define the
1343 subroutine or package before the current location. You can use an empty
1344 "sub foo;" or "package FOO;" to enter a "forward" declaration.
1346 =item dump() better written as CORE::dump()
1348 (W misc) You used the obsolescent C<dump()> built-in function, without fully
1349 qualifying it as C<CORE::dump()>. Maybe it's a typo. See L<perlfunc/dump>.
1351 =item Duplicate free() ignored
1353 (S malloc) An internal routine called free() on something that had
1356 =item elseif should be elsif
1358 (S) There is no keyword "elseif" in Perl because Larry thinks it's ugly.
1359 Your code will be interpreted as an attempt to call a method named
1360 "elseif" for the class returned by the following block. This is
1361 unlikely to be what you want.
1365 (F) C<\p> and C<\P> are used to introduce a named Unicode property, as
1366 described in L<perlunicode> and L<perlre>. You used C<\p> or C<\P> in
1367 a regular expression without specifying the property name.
1369 =item entering effective %s failed
1371 (F) While under the C<use filetest> pragma, switching the real and
1372 effective uids or gids failed.
1374 =item Error converting file specification %s
1376 (F) An error peculiar to VMS. Because Perl may have to deal with file
1377 specifications in either VMS or Unix syntax, it converts them to a
1378 single form when it must operate on them directly. Either you've passed
1379 an invalid file specification to Perl, or you've found a case the
1380 conversion routines don't handle. Drat.
1382 =item %s: Eval-group in insecure regular expression
1384 (F) Perl detected tainted data when trying to compile a regular
1385 expression that contains the C<(?{ ... })> zero-width assertion, which
1386 is unsafe. See L<perlre/(?{ code })>, and L<perlsec>.
1388 =item %s: Eval-group not allowed at run time
1390 (F) Perl tried to compile a regular expression containing the
1391 C<(?{ ... })> zero-width assertion at run time, as it would when the
1392 pattern contains interpolated values. Since that is a security risk, it
1393 is not allowed. If you insist, you may still do this by explicitly
1394 building the pattern from an interpolated string at run time and using
1395 that in an eval(). See L<perlre/(?{ code })>.
1397 =item %s: Eval-group not allowed, use re 'eval'
1399 (F) A regular expression contained the C<(?{ ... })> zero-width
1400 assertion, but that construct is only allowed when the C<use re 'eval'>
1401 pragma is in effect. See L<perlre/(?{ code })>.
1403 =item Excessively long <> operator
1405 (F) The contents of a <> operator may not exceed the maximum size of a
1406 Perl identifier. If you're just trying to glob a long list of
1407 filenames, try using the glob() operator, or put the filenames into a
1408 variable and glob that.
1410 =item exec? I'm not *that* kind of operating system
1412 (F) The C<exec> function is not implemented in MacPerl. See L<perlport>.
1414 =item Execution of %s aborted due to compilation errors
1416 (F) The final summary message when a Perl compilation fails.
1418 =item Exiting eval via %s
1420 (W exiting) You are exiting an eval by unconventional means, such as a
1421 goto, or a loop control statement.
1423 =item Exiting format via %s
1425 (W exiting) You are exiting a format by unconventional means, such as a
1426 goto, or a loop control statement.
1428 =item Exiting pseudo-block via %s
1430 (W exiting) You are exiting a rather special block construct (like a
1431 sort block or subroutine) by unconventional means, such as a goto, or a
1432 loop control statement. See L<perlfunc/sort>.
1434 =item Exiting subroutine via %s
1436 (W exiting) You are exiting a subroutine by unconventional means, such
1437 as a goto, or a loop control statement.
1439 =item Exiting substitution via %s
1441 (W exiting) You are exiting a substitution by unconventional means, such
1442 as a return, a goto, or a loop control statement.
1444 =item Explicit blessing to '' (assuming package main)
1446 (W misc) You are blessing a reference to a zero length string. This has
1447 the effect of blessing the reference into the package main. This is
1448 usually not what you want. Consider providing a default target package,
1449 e.g. bless($ref, $p || 'MyPackage');
1451 =item %s: Expression syntax
1453 (A) You've accidentally run your script through B<csh> instead of Perl.
1454 Check the #! line, or manually feed your script into Perl yourself.
1456 =item %s failed--call queue aborted
1458 (F) An untrapped exception was raised while executing a CHECK, INIT, or
1459 END subroutine. Processing of the remainder of the queue of such
1460 routines has been prematurely ended.
1462 =item False [] range "%s" in regex; marked by <-- HERE in m/%s/
1464 (W regexp) A character class range must start and end at a literal
1465 character, not another character class like C<\d> or C<[:alpha:]>. The "-"
1466 in your false range is interpreted as a literal "-". Consider quoting the
1467 "-", "\-". The <-- HERE shows in the regular expression about where the
1468 problem was discovered. See L<perlre>.
1470 =item Fatal VMS error at %s, line %d
1472 (P) An error peculiar to VMS. Something untoward happened in a VMS
1473 system service or RTL routine; Perl's exit status should provide more
1474 details. The filename in "at %s" and the line number in "line %d" tell
1475 you which section of the Perl source code is distressed.
1477 =item fcntl is not implemented
1479 (F) Your machine apparently doesn't implement fcntl(). What is this, a
1480 PDP-11 or something?
1482 =item Filehandle %s opened only for input
1484 (W io) You tried to write on a read-only filehandle. If you intended it
1485 to be a read-write filehandle, you needed to open it with "+<" or "+>"
1486 or "+>>" instead of with "<" or nothing. If you intended only to write
1487 the file, use ">" or ">>". See L<perlfunc/open>.
1488 The warning will also occur if STDOUT (file descriptor 1) or STDERR
1489 (file descriptor 2) is opened for input, this is a pre-emptive warning in
1490 case some other part of your program or a child process is expecting STDOUT
1491 and STDERR to be writable. This can happen accidentally if you
1492 C<close(STDOUT)> or STDERR and then C<open> an unrelated handle which
1493 will resuse the lowest numbered available descriptor.
1495 =item Filehandle %s opened only for output
1497 (W io) You tried to read from a filehandle opened only for writing.
1498 If you intended it to be a read/write filehandle, you needed to open it
1499 with "+<" or "+>" or "+>>" instead of with "<" or nothing. If you
1500 intended only to read from the file, use "<". See L<perlfunc/open>.
1501 The warning will also occur if STDIN (file descriptor 0) is opened
1502 for output - this is a pre-emptive warning in case some other part of your
1503 program or a child process is expecting STDIN to be readable.
1504 This can happen accidentally if you C<close(STDIN)> and then C<open> an
1505 unrelated handle which will resuse the lowest numbered available
1508 =item Final $ should be \$ or $name
1510 (F) You must now decide whether the final $ in a string was meant to be
1511 a literal dollar sign, or was meant to introduce a variable name that
1512 happens to be missing. So you have to put either the backslash or the
1515 =item Final @ should be \@ or @name
1517 (F) You must now decide whether the final @ in a string was meant to be
1518 a literal "at" sign, or was meant to introduce a variable name that
1519 happens to be missing. So you have to put either the backslash or the
1522 =item flock() on closed filehandle %s
1524 (W closed) The filehandle you're attempting to flock() got itself closed
1525 some time before now. Check your control flow. flock() operates on
1526 filehandles. Are you attempting to call flock() on a dirhandle by the
1529 =item Quantifier follows nothing in regex;
1531 marked by <-- HERE in m/%s/
1533 (F) You started a regular expression with a quantifier. Backslash it if you
1534 meant it literally. The <-- HERE shows in the regular expression about
1535 where the problem was discovered. See L<perlre>.
1537 =item Format not terminated
1539 (F) A format must be terminated by a line with a solitary dot. Perl got
1540 to the end of your file without finding such a line.
1542 =item Format %s redefined
1544 (W redefine) You redefined a format. To suppress this warning, say
1547 no warnings 'redefine';
1548 eval "format NAME =...";
1551 =item Found = in conditional, should be ==
1561 (or something like that).
1563 =item %s found where operator expected
1565 (S) The Perl lexer knows whether to expect a term or an operator. If it
1566 sees what it knows to be a term when it was expecting to see an
1567 operator, it gives you this warning. Usually it indicates that an
1568 operator or delimiter was omitted, such as a semicolon.
1570 =item gdbm store returned %d, errno %d, key "%s"
1572 (S) A warning from the GDBM_File extension that a store failed.
1574 =item gethostent not implemented
1576 (F) Your C library apparently doesn't implement gethostent(), probably
1577 because if it did, it'd feel morally obligated to return every hostname
1580 =item get%sname() on closed socket %s
1582 (W closed) You tried to get a socket or peer socket name on a closed
1583 socket. Did you forget to check the return value of your socket() call?
1585 =item getpwnam returned invalid UIC %#o for user "%s"
1587 (S) A warning peculiar to VMS. The call to C<sys$getuai> underlying the
1588 C<getpwnam> operator returned an invalid UIC.
1590 =item getsockopt() on closed socket %s
1592 (W closed) You tried to get a socket option on a closed socket. Did you
1593 forget to check the return value of your socket() call? See
1594 L<perlfunc/getsockopt>.
1596 =item Global symbol "%s" requires explicit package name
1598 (F) You've said "use strict vars", which indicates that all variables
1599 must either be lexically scoped (using "my"), declared beforehand using
1600 "our", or explicitly qualified to say which package the global variable
1603 =item glob failed (%s)
1605 (W glob) Something went wrong with the external program(s) used for
1606 C<glob> and C<< <*.c> >>. Usually, this means that you supplied a
1607 C<glob> pattern that caused the external program to fail and exit with a
1608 nonzero status. If the message indicates that the abnormal exit
1609 resulted in a coredump, this may also mean that your csh (C shell) is
1610 broken. If so, you should change all of the csh-related variables in
1611 config.sh: If you have tcsh, make the variables refer to it as if it
1612 were csh (e.g. C<full_csh='/usr/bin/tcsh'>); otherwise, make them all
1613 empty (except that C<d_csh> should be C<'undef'>) so that Perl will
1614 think csh is missing. In either case, after editing config.sh, run
1615 C<./Configure -S> and rebuild Perl.
1617 =item Glob not terminated
1619 (F) The lexer saw a left angle bracket in a place where it was expecting
1620 a term, so it's looking for the corresponding right angle bracket, and
1621 not finding it. Chances are you left some needed parentheses out
1622 earlier in the line, and you really meant a "less than".
1624 =item Got an error from DosAllocMem
1626 (P) An error peculiar to OS/2. Most probably you're using an obsolete
1627 version of Perl, and this should not happen anyway.
1629 =item goto must have label
1631 (F) Unlike with "next" or "last", you're not allowed to goto an
1632 unspecified destination. See L<perlfunc/goto>.
1634 =item %s-group starts with a count
1636 (F) In pack/unpack a ()-group started with a count. A count is
1637 supposed to follow something: a template character or a ()-group.
1639 =item %s had compilation errors
1641 (F) The final summary message when a C<perl -c> fails.
1643 =item Had to create %s unexpectedly
1645 (S internal) A routine asked for a symbol from a symbol table that ought
1646 to have existed already, but for some reason it didn't, and had to be
1647 created on an emergency basis to prevent a core dump.
1649 =item Hash %%s missing the % in argument %d of %s()
1651 (D deprecated) Really old Perl let you omit the % on hash names in some
1652 spots. This is now heavily deprecated.
1654 =item %s has too many errors
1656 (F) The parser has given up trying to parse the program after 10 errors.
1657 Further error messages would likely be uninformative.
1659 =item Hexadecimal number > 0xffffffff non-portable
1661 (W portable) The hexadecimal number you specified is larger than 2**32-1
1662 (4294967295) and therefore non-portable between systems. See
1663 L<perlport> for more on portability concerns.
1665 =item Identifier too long
1667 (F) Perl limits identifiers (names for variables, functions, etc.) to
1668 about 250 characters for simple names, and somewhat more for compound
1669 names (like C<$A::B>). You've exceeded Perl's limits. Future versions
1670 of Perl are likely to eliminate these arbitrary limitations.
1672 =item Illegal binary digit %s
1674 (F) You used a digit other than 0 or 1 in a binary number.
1676 =item Illegal binary digit %s ignored
1678 (W digit) You may have tried to use a digit other than 0 or 1 in a
1679 binary number. Interpretation of the binary number stopped before the
1682 =item Illegal character %s (carriage return)
1684 (F) Perl normally treats carriage returns in the program text as it
1685 would any other whitespace, which means you should never see this error
1686 when Perl was built using standard options. For some reason, your
1687 version of Perl appears to have been built without this support. Talk
1688 to your Perl administrator.
1690 =item Illegal character in prototype for %s : %s
1692 (W syntax) An illegal character was found in a prototype declaration. Legal
1693 characters in prototypes are $, @, %, *, ;, [, ], &, and \.
1695 =item Illegal division by zero
1697 (F) You tried to divide a number by 0. Either something was wrong in
1698 your logic, or you need to put a conditional in to guard against
1701 =item Illegal hexadecimal digit %s ignored
1703 (W digit) You may have tried to use a character other than 0 - 9 or
1704 A - F, a - f in a hexadecimal number. Interpretation of the hexadecimal
1705 number stopped before the illegal character.
1707 =item Illegal modulus zero
1709 (F) You tried to divide a number by 0 to get the remainder. Most
1710 numbers don't take to this kindly.
1712 =item Illegal number of bits in vec
1714 (F) The number of bits in vec() (the third argument) must be a power of
1715 two from 1 to 32 (or 64, if your platform supports that).
1717 =item Illegal octal digit %s
1719 (F) You used an 8 or 9 in an octal number.
1721 =item Illegal octal digit %s ignored
1723 (W digit) You may have tried to use an 8 or 9 in an octal number.
1724 Interpretation of the octal number stopped before the 8 or 9.
1726 =item Illegal switch in PERL5OPT: %s
1728 (X) The PERL5OPT environment variable may only be used to set the
1729 following switches: B<-[DIMUdmtw]>.
1731 =item Ill-formed CRTL environ value "%s"
1733 (W internal) A warning peculiar to VMS. Perl tried to read the CRTL's
1734 internal environ array, and encountered an element without the C<=>
1735 delimiter used to separate keys from values. The element is ignored.
1737 =item Ill-formed message in prime_env_iter: |%s|
1739 (W internal) A warning peculiar to VMS. Perl tried to read a logical
1740 name or CLI symbol definition when preparing to iterate over %ENV, and
1741 didn't see the expected delimiter between key and value, so the line was
1744 =item (in cleanup) %s
1746 (W misc) This prefix usually indicates that a DESTROY() method raised
1747 the indicated exception. Since destructors are usually called by the
1748 system at arbitrary points during execution, and often a vast number of
1749 times, the warning is issued only once for any number of failures that
1750 would otherwise result in the same message being repeated.
1752 Failure of user callbacks dispatched using the C<G_KEEPERR> flag could
1753 also result in this warning. See L<perlcall/G_KEEPERR>.
1755 =item In EBCDIC the v-string components cannot exceed 2147483647
1757 (F) An error peculiar to EBCDIC. Internally, v-strings are stored as
1758 Unicode code points, and encoded in EBCDIC as UTF-EBCDIC. The UTF-EBCDIC
1759 encoding is limited to code points no larger than 2147483647 (0x7FFFFFFF).
1761 =item Insecure dependency in %s
1763 (F) You tried to do something that the tainting mechanism didn't like.
1764 The tainting mechanism is turned on when you're running setuid or
1765 setgid, or when you specify B<-T> to turn it on explicitly. The
1766 tainting mechanism labels all data that's derived directly or indirectly
1767 from the user, who is considered to be unworthy of your trust. If any
1768 such data is used in a "dangerous" operation, you get this error. See
1769 L<perlsec> for more information.
1771 =item Insecure directory in %s
1773 (F) You can't use system(), exec(), or a piped open in a setuid or
1774 setgid script if C<$ENV{PATH}> contains a directory that is writable by
1775 the world. See L<perlsec>.
1777 =item Insecure $ENV{%s} while running %s
1779 (F) You can't use system(), exec(), or a piped open in a setuid or
1780 setgid script if any of C<$ENV{PATH}>, C<$ENV{IFS}>, C<$ENV{CDPATH}>,
1781 C<$ENV{ENV}> or C<$ENV{BASH_ENV}> are derived from data supplied (or
1782 potentially supplied) by the user. The script must set the path to a
1783 known value, using trustworthy data. See L<perlsec>.
1785 =item Integer overflow in %s number
1787 (W overflow) The hexadecimal, octal or binary number you have specified
1788 either as a literal or as an argument to hex() or oct() is too big for
1789 your architecture, and has been converted to a floating point number.
1790 On a 32-bit architecture the largest hexadecimal, octal or binary number
1791 representable without overflow is 0xFFFFFFFF, 037777777777, or
1792 0b11111111111111111111111111111111 respectively. Note that Perl
1793 transparently promotes all numbers to a floating point representation
1794 internally--subject to loss of precision errors in subsequent
1797 =item Internal disaster in regex; marked by <-- HERE in m/%s/
1799 (P) Something went badly wrong in the regular expression parser.
1800 The <-- HERE shows in the regular expression about where the problem was
1803 =item Internal inconsistency in tracking vforks
1805 (S) A warning peculiar to VMS. Perl keeps track of the number of times
1806 you've called C<fork> and C<exec>, to determine whether the current call
1807 to C<exec> should affect the current script or a subprocess (see
1808 L<perlvms/"exec LIST">). Somehow, this count has become scrambled, so
1809 Perl is making a guess and treating this C<exec> as a request to
1810 terminate the Perl script and execute the specified command.
1812 =item Internal urp in regex; marked by <-- HERE in m/%s/
1814 (P) Something went badly awry in the regular expression parser. The
1815 <-- HERE shows in the regular expression about where the problem was
1818 =item %s (...) interpreted as function
1820 (W syntax) You've run afoul of the rule that says that any list operator
1821 followed by parentheses turns into a function, with all the list
1822 operators arguments found inside the parentheses. See
1823 L<perlop/Terms and List Operators (Leftward)>.
1825 =item Invalid %s attribute: %s
1827 The indicated attribute for a subroutine or variable was not recognized
1828 by Perl or by a user-supplied handler. See L<attributes>.
1830 =item Invalid %s attributes: %s
1832 The indicated attributes for a subroutine or variable were not
1833 recognized by Perl or by a user-supplied handler. See L<attributes>.
1835 =item Invalid conversion in %s: "%s"
1837 (W printf) Perl does not understand the given format conversion. See
1838 L<perlfunc/sprintf>.
1840 =item Invalid [] range "%s" in regex; marked by <-- HERE in m/%s/
1842 (F) The range specified in a character class had a minimum character
1843 greater than the maximum character. One possibility is that you forgot the
1844 C<{}> from your ending C<\x{}> - C<\x> without the curly braces can go only
1845 up to C<ff>. The <-- HERE shows in the regular expression about where the
1846 problem was discovered. See L<perlre>.
1848 =item Invalid [] range "%s" in transliteration operator
1850 (F) The range specified in the tr/// or y/// operator had a minimum
1851 character greater than the maximum character. See L<perlop>.
1853 =item Invalid separator character %s in attribute list
1855 (F) Something other than a colon or whitespace was seen between the
1856 elements of an attribute list. If the previous attribute had a
1857 parenthesised parameter list, perhaps that list was terminated too soon.
1860 =item Invalid type in pack: '%s'
1862 (F) The given character is not a valid pack type. See L<perlfunc/pack>.
1863 (W pack) The given character is not a valid pack type but used to be
1866 =item Invalid type in unpack: '%s'
1868 (F) The given character is not a valid unpack type. See
1870 (W unpack) The given character is not a valid unpack type but used to be
1873 =item ioctl is not implemented
1875 (F) Your machine apparently doesn't implement ioctl(), which is pretty
1876 strange for a machine that supports C.
1878 =item ioctl() on unopened %s
1880 (W unopened) You tried ioctl() on a filehandle that was never opened.
1881 Check you control flow and number of arguments.
1883 =item IO::Socket::atmark not implemented on this architecture
1885 (F) Your machine doesn't implement the sockatmark() functionality,
1886 neither as a system call or an ioctl call (SIOCATMARK).
1888 =item `%s' is not a code reference
1890 (W overload) The second (fourth, sixth, ...) argument of overload::constant
1891 needs to be a code reference. Either an anonymous subroutine, or a reference
1894 =item `%s' is not an overloadable type
1896 (W overload) You tried to overload a constant type the overload package is
1899 =item junk on end of regexp
1901 (P) The regular expression parser is confused.
1903 =item Label not found for "last %s"
1905 (F) You named a loop to break out of, but you're not currently in a loop
1906 of that name, not even if you count where you were called from. See
1909 =item Label not found for "next %s"
1911 (F) You named a loop to continue, but you're not currently in a loop of
1912 that name, not even if you count where you were called from. See
1915 =item Label not found for "redo %s"
1917 (F) You named a loop to restart, but you're not currently in a loop of
1918 that name, not even if you count where you were called from. See
1921 =item leaving effective %s failed
1923 (F) While under the C<use filetest> pragma, switching the real and
1924 effective uids or gids failed.
1926 =item listen() on closed socket %s
1928 (W closed) You tried to do a listen on a closed socket. Did you forget
1929 to check the return value of your socket() call? See
1932 =item lstat() on filehandle %s
1934 (W io) You tried to do an lstat on a filehandle. What did you mean
1935 by that? lstat() makes sense only on filenames. (Perl did a fstat()
1936 instead on the filehandle.)
1938 =item Lvalue subs returning %s not implemented yet
1940 (F) Due to limitations in the current implementation, array and hash
1941 values cannot be returned in subroutines used in lvalue context. See
1942 L<perlsub/"Lvalue subroutines">.
1944 =item Lookbehind longer than %d not implemented in regex;
1946 marked by <-- HERE in m/%s/
1948 (F) There is currently a limit on the length of string which lookbehind can
1949 handle. This restriction may be eased in a future release. The <-- HERE
1950 shows in the regular expression about where the problem was discovered.
1952 =item Malformed PERLLIB_PREFIX
1954 (F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form
1961 with nonempty prefix1 and prefix2. If C<prefix1> is indeed a prefix of
1962 a builtin library search path, prefix2 is substituted. The error may
1963 appear if components are not found, or are too long. See
1964 "PERLLIB_PREFIX" in L<perlos2>.
1966 =item Malformed prototype for %s: %s
1968 (F) You tried to use a function with a malformed prototype. The
1969 syntax of function prototypes is given a brief compile-time check for
1970 obvious errors like invalid characters. A more rigorous check is run
1971 when the function is called.
1973 =item Malformed UTF-8 character (%s)
1975 Perl detected something that didn't comply with UTF-8 encoding rules.
1977 One possible cause is that you read in data that you thought to be in
1978 UTF-8 but it wasn't (it was for example legacy 8-bit data). Another
1979 possibility is careless use of utf8::upgrade().
1981 =item Malformed UTF-16 surrogate
1983 Perl thought it was reading UTF-16 encoded character data but while
1984 doing it Perl met a malformed Unicode surrogate.
1986 =item %s matches null string many times in regex;
1988 marked by <-- HERE in m/%s/
1990 (W regexp) The pattern you've specified would be an infinite loop if the
1991 regular expression engine didn't specifically check for that. The <-- HERE
1992 shows in the regular expression about where the problem was discovered.
1995 =item "%s" may clash with future reserved word
1997 (W) This warning may be due to running a perl5 script through a perl4
1998 interpreter, especially if the word that is being warned about is
2001 =item % may only be used in unpack
2003 (F) You can't pack a string by supplying a checksum, because the
2004 checksumming process loses information, and you can't go the other way.
2005 See L<perlfunc/unpack>.
2007 =item Method for operation %s not found in package %s during blessing
2009 (F) An attempt was made to specify an entry in an overloading table that
2010 doesn't resolve to a valid subroutine. See L<overload>.
2012 =item Method %s not permitted
2016 =item Might be a runaway multi-line %s string starting on line %d
2018 (S) An advisory indicating that the previous error may have been caused
2019 by a missing delimiter on a string or pattern, because it eventually
2020 ended earlier on the current line.
2022 =item Misplaced _ in number
2024 (W syntax) An underscore (underbar) in a numeric constant did not
2025 separate two digits.
2027 =item Missing %sbrace%s on \N{}
2029 (F) Wrong syntax of character name literal C<\N{charname}> within
2030 double-quotish context.
2032 =item Missing comma after first argument to %s function
2034 (F) While certain functions allow you to specify a filehandle or an
2035 "indirect object" before the argument list, this ain't one of them.
2037 =item Missing command in piped open
2039 (W pipe) You used the C<open(FH, "| command")> or
2040 C<open(FH, "command |")> construction, but the command was missing or
2043 =item Missing name in "my sub"
2045 (F) The reserved syntax for lexically scoped subroutines requires that
2046 they have a name with which they can be found.
2048 =item Missing $ on loop variable
2050 (F) Apparently you've been programming in B<csh> too much. Variables
2051 are always mentioned with the $ in Perl, unlike in the shells, where it
2052 can vary from one line to the next.
2054 =item (Missing operator before %s?)
2056 (S) This is an educated guess made in conjunction with the message "%s
2057 found where operator expected". Often the missing operator is a comma.
2059 =item Missing right brace on %s
2061 (F) Missing right brace in C<\p{...}> or C<\P{...}>.
2063 =item Missing right curly or square bracket
2065 (F) The lexer counted more opening curly or square brackets than closing
2066 ones. As a general rule, you'll find it's missing near the place you
2069 =item (Missing semicolon on previous line?)
2071 (S) This is an educated guess made in conjunction with the message "%s
2072 found where operator expected". Don't automatically put a semicolon on
2073 the previous line just because you saw this message.
2075 =item Modification of a read-only value attempted
2077 (F) You tried, directly or indirectly, to change the value of a
2078 constant. You didn't, of course, try "2 = 1", because the compiler
2079 catches that. But an easy way to do the same thing is:
2081 sub mod { $_[0] = 1 }
2084 Another way is to assign to a substr() that's off the end of the string.
2086 Yet another way is to assign to a C<foreach> loop I<VAR> when I<VAR>
2087 is aliased to a constant in the look I<LIST>:
2090 foreach my $n ($x, 2) {
2091 $n *= 2; # modifies the $x, but fails on attempt to modify the 2
2094 =item Modification of non-creatable array value attempted, %s
2096 (F) You tried to make an array value spring into existence, and the
2097 subscript was probably negative, even counting from end of the array
2100 =item Modification of non-creatable hash value attempted, %s
2102 (P) You tried to make a hash value spring into existence, and it
2103 couldn't be created for some peculiar reason.
2105 =item Module name must be constant
2107 (F) Only a bare module name is allowed as the first argument to a "use".
2109 =item Module name required with -%c option
2111 (F) The C<-M> or C<-m> options say that Perl should load some module, but
2112 you omitted the name of the module. Consult L<perlrun> for full details
2113 about C<-M> and C<-m>.
2115 =item More than one argument to open
2117 (F) The C<open> function has been asked to open multiple files. This
2118 can happen if you are trying to open a pipe to a command that takes a
2119 list of arguments, but have forgotten to specify a piped open mode.
2120 See L<perlfunc/open> for details.
2122 =item msg%s not implemented
2124 (F) You don't have System V message IPC on your system.
2126 =item Multidimensional syntax %s not supported
2128 (W syntax) Multidimensional arrays aren't written like C<$foo[1,2,3]>.
2129 They're written like C<$foo[1][2][3]>, as in C.
2131 =item / must be followed by a*, A* or Z*
2133 (F) You had a pack template indicating a counted-length string,
2134 Currently the only things that can have their length counted are a*, A*
2135 or Z*. See L<perlfunc/pack>.
2137 =item / must be followed by a, A or Z
2139 (F) You had an unpack template indicating a counted-length string, which
2140 must be followed by one of the letters a, A or Z to indicate what sort
2141 of string is to be unpacked. See L<perlfunc/pack>.
2143 =item / must follow a numeric type
2145 (F) You had an unpack template that contained a '#', but this did not
2146 follow some numeric unpack specification. See L<perlfunc/pack>.
2148 =item "my sub" not yet implemented
2150 (F) Lexically scoped subroutines are not yet implemented. Don't try
2153 =item "my" variable %s can't be in a package
2155 (F) Lexically scoped variables aren't in a package, so it doesn't make
2156 sense to try to declare one with a package qualifier on the front. Use
2157 local() if you want to localize a package variable.
2159 =item Name "%s::%s" used only once: possible typo
2161 (W once) Typographical errors often show up as unique variable names.
2162 If you had a good reason for having a unique name, then just mention it
2163 again somehow to suppress the message. The C<our> declaration is
2164 provided for this purpose.
2166 =item Negative length
2168 (F) You tried to do a read/write/send/recv operation with a buffer
2169 length that is less than 0. This is difficult to imagine.
2171 =item Negative offset to vec in lvalue context
2173 (F) When C<vec> is called in an lvalue context, the second argument must be
2174 greater than or equal to zero.
2176 =item Nested quantifiers in regex; marked by <-- HERE in m/%s/
2178 (F) You can't quantify a quantifier without intervening parentheses. So
2179 things like ** or +* or ?* are illegal. The <-- HERE shows in the regular
2180 expression about where the problem was discovered.
2182 Note that the minimal matching quantifiers, C<*?>, C<+?>, and
2183 C<??> appear to be nested quantifiers, but aren't. See L<perlre>.
2185 =item %s never introduced
2187 (S internal) The symbol in question was declared but somehow went out of
2188 scope before it could possibly have been used.
2190 =item No %s allowed while running setuid
2192 (F) Certain operations are deemed to be too insecure for a setuid or
2193 setgid script to even be allowed to attempt. Generally speaking there
2194 will be another way to do what you want that is, if not secure, at least
2195 securable. See L<perlsec>.
2197 =item No B<-e> allowed in setuid scripts
2199 (F) A setuid script can't be specified by the user.
2201 =item No comma allowed after %s
2203 (F) A list operator that has a filehandle or "indirect object" is not
2204 allowed to have a comma between that and the following arguments.
2205 Otherwise it'd be just another one of the arguments.
2207 One possible cause for this is that you expected to have imported a
2208 constant to your name space with B<use> or B<import> while no such
2209 importing took place, it may for example be that your operating system
2210 does not support that particular constant. Hopefully you did use an
2211 explicit import list for the constants you expect to see, please see
2212 L<perlfunc/use> and L<perlfunc/import>. While an explicit import list
2213 would probably have caught this error earlier it naturally does not
2214 remedy the fact that your operating system still does not support that
2215 constant. Maybe you have a typo in the constants of the symbol import
2216 list of B<use> or B<import> or in the constant name at the line where
2217 this error was triggered?
2219 =item No command into which to pipe on command line
2221 (F) An error peculiar to VMS. Perl handles its own command line
2222 redirection, and found a '|' at the end of the command line, so it
2223 doesn't know where you want to pipe the output from this command.
2225 =item No DB::DB routine defined
2227 (F) The currently executing code was compiled with the B<-d> switch, but
2228 for some reason the perl5db.pl file (or some facsimile thereof) didn't
2229 define a routine to be called at the beginning of each statement. Which
2230 is odd, because the file should have been required automatically, and
2231 should have blown up the require if it didn't parse right.
2233 =item No dbm on this machine
2235 (P) This is counted as an internal error, because every machine should
2236 supply dbm nowadays, because Perl comes with SDBM. See L<SDBM_File>.
2238 =item No DBsub routine
2240 (F) The currently executing code was compiled with the B<-d> switch,
2241 but for some reason the perl5db.pl file (or some facsimile thereof)
2242 didn't define a DB::sub routine to be called at the beginning of each
2243 ordinary subroutine call.
2245 =item No error file after 2> or 2>> on command line
2247 (F) An error peculiar to VMS. Perl handles its own command line
2248 redirection, and found a '2>' or a '2>>' on the command line, but can't
2249 find the name of the file to which to write data destined for stderr.
2251 =item No input file after < on command line
2253 (F) An error peculiar to VMS. Perl handles its own command line
2254 redirection, and found a '<' on the command line, but can't find the
2255 name of the file from which to read data for stdin.
2259 (F) The setuid emulator requires that scripts have a well-formed #! line
2260 even on machines that don't support the #! construct.
2262 =item "no" not allowed in expression
2264 (F) The "no" keyword is recognized and executed at compile time, and
2265 returns no useful value. See L<perlmod>.
2267 =item No output file after > on command line
2269 (F) An error peculiar to VMS. Perl handles its own command line
2270 redirection, and found a lone '>' at the end of the command line, so it
2271 doesn't know where you wanted to redirect stdout.
2273 =item No output file after > or >> on command line
2275 (F) An error peculiar to VMS. Perl handles its own command line
2276 redirection, and found a '>' or a '>>' on the command line, but can't
2277 find the name of the file to which to write data destined for stdout.
2279 =item No package name allowed for variable %s in "our"
2281 (F) Fully qualified variable names are not allowed in "our"
2282 declarations, because that doesn't make much sense under existing
2283 semantics. Such syntax is reserved for future extensions.
2285 =item No Perl script found in input
2287 (F) You called C<perl -x>, but no line was found in the file beginning
2288 with #! and containing the word "perl".
2290 =item No setregid available
2292 (F) Configure didn't find anything resembling the setregid() call for
2295 =item No setreuid available
2297 (F) Configure didn't find anything resembling the setreuid() call for
2300 =item No space allowed after -%c
2302 (F) The argument to the indicated command line switch must follow
2303 immediately after the switch, without intervening spaces.
2305 =item No %s specified for -%c
2307 (F) The indicated command line switch needs a mandatory argument, but
2308 you haven't specified one.
2310 =item No such class %s
2312 (F) You provided a class qualifier in a "my" or "our" declaration, but
2313 this class doesn't exist at this point in your program.
2315 =item No such pipe open
2317 (P) An error peculiar to VMS. The internal routine my_pclose() tried to
2318 close a pipe which hadn't been opened. This should have been caught
2319 earlier as an attempt to close an unopened filehandle.
2321 =item No such signal: SIG%s
2323 (W signal) You specified a signal name as a subscript to %SIG that was
2324 not recognized. Say C<kill -l> in your shell to see the valid signal
2325 names on your system.
2327 =item Not a CODE reference
2329 (F) Perl was trying to evaluate a reference to a code value (that is, a
2330 subroutine), but found a reference to something else instead. You can
2331 use the ref() function to find out what kind of ref it really was. See
2334 =item Not a format reference
2336 (F) I'm not sure how you managed to generate a reference to an anonymous
2337 format, but this indicates you did, and that it didn't exist.
2339 =item Not a GLOB reference
2341 (F) Perl was trying to evaluate a reference to a "typeglob" (that is, a
2342 symbol table entry that looks like C<*foo>), but found a reference to
2343 something else instead. You can use the ref() function to find out what
2344 kind of ref it really was. See L<perlref>.
2346 =item Not a HASH reference
2348 (F) Perl was trying to evaluate a reference to a hash value, but found a
2349 reference to something else instead. You can use the ref() function to
2350 find out what kind of ref it really was. See L<perlref>.
2352 =item Not an ARRAY reference
2354 (F) Perl was trying to evaluate a reference to an array value, but found
2355 a reference to something else instead. You can use the ref() function
2356 to find out what kind of ref it really was. See L<perlref>.
2358 =item Not a perl script
2360 (F) The setuid emulator requires that scripts have a well-formed #! line
2361 even on machines that don't support the #! construct. The line must
2364 =item Not a SCALAR reference
2366 (F) Perl was trying to evaluate a reference to a scalar value, but found
2367 a reference to something else instead. You can use the ref() function
2368 to find out what kind of ref it really was. See L<perlref>.
2370 =item Not a subroutine reference
2372 (F) Perl was trying to evaluate a reference to a code value (that is, a
2373 subroutine), but found a reference to something else instead. You can
2374 use the ref() function to find out what kind of ref it really was. See
2377 =item Not a subroutine reference in overload table
2379 (F) An attempt was made to specify an entry in an overloading table that
2380 doesn't somehow point to a valid subroutine. See L<overload>.
2382 =item Not enough arguments for %s
2384 (F) The function requires more arguments than you specified.
2386 =item Not enough format arguments
2388 (W syntax) A format specified more picture fields than the next line
2389 supplied. See L<perlform>.
2393 (A) You've accidentally run your script through the Bourne shell instead
2394 of Perl. Check the #! line, or manually feed your script into Perl
2397 =item %s not allowed in length fields
2399 (F) The count in the (un)pack template may be replaced by C<[TEMPLATE]> only if
2400 C<TEMPLATE> always matches the same amount of packed bytes. Redesign
2403 =item no UTC offset information; assuming local time is UTC
2405 (S) A warning peculiar to VMS. Perl was unable to find the local
2406 timezone offset, so it's assuming that local system time is equivalent
2407 to UTC. If it's not, define the logical name
2408 F<SYS$TIMEZONE_DIFFERENTIAL> to translate to the number of seconds which
2409 need to be added to UTC to get local time.
2411 =item Null filename used
2413 (F) You can't require the null filename, especially because on many
2414 machines that means the current directory! See L<perlfunc/require>.
2416 =item NULL OP IN RUN
2418 (P debugging) Some internal routine called run() with a null opcode
2421 =item Null picture in formline
2423 (F) The first argument to formline must be a valid format picture
2424 specification. It was found to be empty, which probably means you
2425 supplied it an uninitialized value. See L<perlform>.
2429 (P) An attempt was made to realloc NULL.
2431 =item NULL regexp argument
2433 (P) The internal pattern matching routines blew it big time.
2435 =item NULL regexp parameter
2437 (P) The internal pattern matching routines are out of their gourd.
2439 =item Number too long
2441 (F) Perl limits the representation of decimal numbers in programs to
2442 about 250 characters. You've exceeded that length. Future
2443 versions of Perl are likely to eliminate this arbitrary limitation. In
2444 the meantime, try using scientific notation (e.g. "1e6" instead of
2447 =item Octal number in vector unsupported
2449 (F) Numbers with a leading C<0> are not currently allowed in vectors.
2450 The octal number interpretation of such numbers may be supported in a
2453 =item Octal number > 037777777777 non-portable
2455 (W portable) The octal number you specified is larger than 2**32-1
2456 (4294967295) and therefore non-portable between systems. See
2457 L<perlport> for more on portability concerns.
2459 See also L<perlport> for writing portable code.
2461 =item Odd number of arguments for overload::constant
2463 (W overload) The call to overload::constant contained an odd number of
2464 arguments. The arguments should come in pairs.
2466 =item Odd number of elements in anonymous hash
2468 (W misc) You specified an odd number of elements to initialize a hash,
2469 which is odd, because hashes come in key/value pairs.
2471 =item Odd number of elements in hash assignment
2473 (W misc) You specified an odd number of elements to initialize a hash,
2474 which is odd, because hashes come in key/value pairs.
2476 =item Offset outside string
2478 (F) You tried to do a read/write/send/recv operation with an offset
2479 pointing outside the buffer. This is difficult to imagine. The sole
2480 exception to this is that C<sysread()>ing past the buffer will extend
2481 the buffer and zero pad the new area.
2483 =item -%s on unopened filehandle %s
2485 (W unopened) You tried to invoke a file test operator on a filehandle
2486 that isn't open. Check your control flow. See also L<perlfunc/-X>.
2488 =item %s() on unopened %s
2490 (W unopened) An I/O operation was attempted on a filehandle that was
2491 never initialized. You need to do an open(), a sysopen(), or a socket()
2492 call, or call a constructor from the FileHandle package.
2496 (S internal) An internal warning that the grammar is screwed up.
2500 (S internal) An internal warning that the grammar is screwed up.
2502 =item Operation `%s': no method found, %s
2504 (F) An attempt was made to perform an overloaded operation for which no
2505 handler was defined. While some handlers can be autogenerated in terms
2506 of other handlers, there is no default handler for any operation, unless
2507 C<fallback> overloading key is specified to be true. See L<overload>.
2509 =item Operator or semicolon missing before %s
2511 (S ambiguous) You used a variable or subroutine call where the parser
2512 was expecting an operator. The parser has assumed you really meant to
2513 use an operator, but this is highly likely to be incorrect. For
2514 example, if you say "*foo *foo" it will be interpreted as if you said
2517 =item "our" variable %s redeclared
2519 (W misc) You seem to have already declared the same global once before
2520 in the current lexical scope.
2522 =item Out of memory!
2524 (X) The malloc() function returned 0, indicating there was insufficient
2525 remaining memory (or virtual memory) to satisfy the request. Perl has
2526 no option but to exit immediately.
2528 =item Out of memory during "large" request for %s
2530 (F) The malloc() function returned 0, indicating there was insufficient
2531 remaining memory (or virtual memory) to satisfy the request. However,
2532 the request was judged large enough (compile-time default is 64K), so a
2533 possibility to shut down by trapping this error is granted.
2535 =item Out of memory during request for %s
2537 (X|F) The malloc() function returned 0, indicating there was
2538 insufficient remaining memory (or virtual memory) to satisfy the
2541 The request was judged to be small, so the possibility to trap it
2542 depends on the way perl was compiled. By default it is not trappable.
2543 However, if compiled for this, Perl may use the contents of C<$^M> as an
2544 emergency pool after die()ing with this message. In this case the error
2545 is trappable I<once>, and the error message will include the line and file
2546 where the failed request happened.
2548 =item Out of memory during ridiculously large request
2550 (F) You can't allocate more than 2^31+"small amount" bytes. This error
2551 is most likely to be caused by a typo in the Perl program. e.g.,
2552 C<$arr[time]> instead of C<$arr[$time]>.
2554 =item Out of memory for yacc stack
2556 (F) The yacc parser wanted to grow its stack so it could continue
2557 parsing, but realloc() wouldn't give it more memory, virtual or
2560 =item @ outside of string
2562 (F) You had a pack template that specified an absolute position outside
2563 the string being unpacked. See L<perlfunc/pack>.
2565 =item %s package attribute may clash with future reserved word: %s
2567 (W reserved) A lowercase attribute name was used that had a
2568 package-specific handler. That name might have a meaning to Perl itself
2569 some day, even though it doesn't yet. Perhaps you should use a
2570 mixed-case attribute name, instead. See L<attributes>.
2574 (W io) A single call to write() produced more lines than can fit on a
2575 page. See L<perlform>.
2579 (P) An internal error.
2581 =item panic: ck_grep
2583 (P) Failed an internal consistency check trying to compile a grep.
2585 =item panic: ck_split
2587 (P) Failed an internal consistency check trying to compile a split.
2589 =item panic: corrupt saved stack index
2591 (P) The savestack was requested to restore more localized values than
2592 there are in the savestack.
2594 =item panic: del_backref
2596 (P) Failed an internal consistency check while trying to reset a weak
2601 (P) We popped the context stack to an eval context, and then discovered
2602 it wasn't an eval context.
2604 =item panic: pp_match%s
2606 (P) The internal pp_match() routine was called with invalid operational
2609 =item panic: do_subst
2611 (P) The internal pp_subst() routine was called with invalid operational
2614 =item panic: do_trans_%s
2616 (P) The internal do_trans routines were called with invalid operational
2621 (P) The library function frexp() failed, making printf("%f") impossible.
2625 (P) We popped the context stack to a context with the specified label,
2626 and then discovered it wasn't a context we know how to do a goto in.
2628 =item panic: INTERPCASEMOD
2630 (P) The lexer got into a bad state at a case modifier.
2632 =item panic: INTERPCONCAT
2634 (P) The lexer got into a bad state parsing a string with brackets.
2636 =item panic: kid popen errno read
2638 (F) forked child returned an incomprehensible message about its errno.
2642 (P) We popped the context stack to a block context, and then discovered
2643 it wasn't a block context.
2645 =item panic: leave_scope clearsv
2647 (P) A writable lexical variable became read-only somehow within the
2650 =item panic: leave_scope inconsistency
2652 (P) The savestack probably got out of sync. At least, there was an
2653 invalid enum on the top of it.
2655 =item panic: magic_killbackrefs
2657 (P) Failed an internal consistency check while trying to reset all weak
2658 references to an object.
2662 (P) Something requested a negative number of bytes of malloc.
2664 =item panic: mapstart
2666 (P) The compiler is screwed up with respect to the map() function.
2668 =item panic: null array
2670 (P) One of the internal array routines was passed a null AV pointer.
2672 =item panic: pad_alloc
2674 (P) The compiler got confused about which scratch pad it was allocating
2675 and freeing temporaries and lexicals from.
2677 =item panic: pad_free curpad
2679 (P) The compiler got confused about which scratch pad it was allocating
2680 and freeing temporaries and lexicals from.
2682 =item panic: pad_free po
2684 (P) An invalid scratch pad offset was detected internally.
2686 =item panic: pad_reset 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_sv po
2693 (P) An invalid scratch pad offset was detected internally.
2695 =item panic: pad_swipe 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_swipe po
2702 (P) An invalid scratch pad offset was detected internally.
2704 =item panic: pp_iter
2706 (P) The foreach iterator got called in a non-loop context frame.
2708 =item panic: pp_split
2710 (P) Something terrible went wrong in setting up for the split.
2712 =item panic: realloc
2714 (P) Something requested a negative number of bytes of realloc.
2716 =item panic: restartop
2718 (P) Some internal routine requested a goto (or something like it), and
2719 didn't supply the destination.
2723 (P) We popped the context stack to a subroutine or eval context, and
2724 then discovered it wasn't a subroutine or eval context.
2726 =item panic: scan_num
2728 (P) scan_num() got called on something that wasn't a number.
2730 =item panic: sv_insert
2732 (P) The sv_insert() routine was told to remove more string than there
2735 =item panic: top_env
2737 (P) The compiler attempted to do a goto, or something weird like that.
2741 (P) The lexer got into a bad state while processing a case modifier.
2743 =item panic: utf16_to_utf8: odd bytelen
2745 (P) Something tried to call utf16_to_utf8 with an odd (as opposed
2746 to even) byte length.
2748 =item Parentheses missing around "%s" list
2750 (W parenthesis) You said something like
2756 my ($foo, $bar) = @_;
2758 Remember that "my", "our", and "local" bind tighter than comma.
2760 =item Perl %s required--this is only version %s, stopped
2762 (F) The module in question uses features of a version of Perl more
2763 recent than the currently running version. How long has it been since
2764 you upgraded, anyway? See L<perlfunc/require>.
2766 =item PERL_SH_DIR too long
2768 (F) An error peculiar to OS/2. PERL_SH_DIR is the directory to find the
2769 C<sh>-shell in. See "PERL_SH_DIR" in L<perlos2>.
2771 =item perl: warning: Setting locale failed.
2773 (S) The whole warning message will look something like:
2775 perl: warning: Setting locale failed.
2776 perl: warning: Please check that your locale settings:
2779 are supported and installed on your system.
2780 perl: warning: Falling back to the standard locale ("C").
2782 Exactly what were the failed locale settings varies. In the above the
2783 settings were that the LC_ALL was "En_US" and the LANG had no value.
2784 This error means that Perl detected that you and/or your operating
2785 system supplier and/or system administrator have set up the so-called
2786 locale system but Perl could not use those settings. This was not
2787 dead serious, fortunately: there is a "default locale" called "C" that
2788 Perl can and will use, the script will be run. Before you really fix
2789 the problem, however, you will get the same error message each time
2790 you run Perl. How to really fix the problem can be found in
2791 L<perllocale> section B<LOCALE PROBLEMS>.
2793 =item perlio: argument list not closed for layer "%s"
2795 (W layer) When pushing a layer with arguments onto the Perl I/O system you
2796 forgot the ) that closes the argument list. (Layers take care of transforming
2797 data between external and internal representations.) Perl stopped parsing
2798 the layer list at this point and did not attempt to push this layer.
2799 If your program didn't explicitly request the failing operation, it may be
2800 the result of the value of the environment variable PERLIO.
2802 =item perlio: invalid separator character %s in layer specification list %s
2804 (W layer) When pushing layers onto the Perl I/O system, something other than a
2805 colon or whitespace was seen between the elements of a layer list.
2806 If the previous attribute had a parenthesised parameter list, perhaps that
2807 list was terminated too soon.
2809 =item perlio: unknown layer "%s"
2811 (W layer) An attempt was made to push an unknown layer onto the Perl I/O
2812 system. (Layers take care of transforming data between external and
2813 internal representations.) Note that some layers, such as C<mmap>,
2814 are not supported in all environments. If your program didn't
2815 explicitly request the failing operation, it may be the result of the
2816 value of the environment variable PERLIO.
2818 =item Permission denied
2820 (F) The setuid emulator in suidperl decided you were up to no good.
2822 =item pid %x not a child
2824 (W exec) A warning peculiar to VMS. Waitpid() was asked to wait for a
2825 process which isn't a subprocess of the current process. While this is
2826 fine from VMS' perspective, it's probably not what you intended.
2828 =item P must have an explicit size
2830 (F) The unpack format P must have an explicit size, not "*".
2832 =item POSIX syntax [%s] belongs inside character classes in regex;
2834 marked by <-- HERE in m/%s/
2836 (W regexp) The character class constructs [: :], [= =], and [. .] go
2837 I<inside> character classes, the [] are part of the construct, for example:
2838 /[012[:alpha:]345]/. Note that [= =] and [. .] are not currently
2839 implemented; they are simply placeholders for future extensions and will
2840 cause fatal errors. The <-- HERE shows in the regular expression about
2841 where the problem was discovered. See L<perlre>.
2843 =item POSIX syntax [. .] is reserved for future extensions in regex;
2845 marked by <-- HERE in m/%s/
2847 (F regexp) Within regular expression character classes ([]) the syntax
2848 beginning with "[." and ending with ".]" is reserved for future extensions.
2849 If you need to represent those character sequences inside a regular
2850 expression character class, just quote the square brackets with the
2851 backslash: "\[." and ".\]". The <-- HERE shows in the regular expression
2852 about where the problem was discovered. See L<perlre>.
2854 =item POSIX syntax [= =] is reserved for future extensions in regex;
2856 marked by <-- HERE in m/%s/
2858 (F) Within regular expression character classes ([]) the syntax beginning
2859 with "[=" and ending with "=]" is reserved for future extensions. If you
2860 need to represent those character sequences inside a regular expression
2861 character class, just quote the square brackets with the backslash: "\[="
2862 and "=\]". The <-- HERE shows in the regular expression about where the
2863 problem was discovered. See L<perlre>.
2865 =item POSIX class [:%s:] unknown in regex;
2867 marked by <-- HERE in m/%s/
2869 (F) The class in the character class [: :] syntax is unknown. The <-- HERE
2870 shows in the regular expression about where the problem was discovered.
2871 Note that the POSIX character classes do B<not> have the C<is> prefix
2872 the corresponding C interfaces have: in other words, it's C<[[:print:]]>,
2873 not C<isprint>. See L<perlre>.
2875 =item POSIX getpgrp can't take an argument
2877 (F) Your system has POSIX getpgrp(), which takes no argument, unlike
2878 the BSD version, which takes a pid.
2880 =item Possible attempt to put comments in qw() list
2882 (W qw) qw() lists contain items separated by whitespace; as with literal
2883 strings, comment characters are not ignored, but are instead treated as
2884 literal data. (You may have used different delimiters than the
2885 parentheses shown here; braces are also frequently used.)
2887 You probably wrote something like this:
2894 when you should have written this:
2901 If you really want comments, build your list the
2902 old-fashioned way, with quotes and commas:
2906 'b', # another comment
2909 =item Possible attempt to separate words with commas
2911 (W qw) qw() lists contain items separated by whitespace; therefore
2912 commas aren't needed to separate the items. (You may have used
2913 different delimiters than the parentheses shown here; braces are also
2916 You probably wrote something like this:
2920 which puts literal commas into some of the list items. Write it without
2921 commas if you don't want them to appear in your data:
2925 =item Possible memory corruption: %s overflowed 3rd argument
2927 (F) An ioctl() or fcntl() returned more than Perl was bargaining for.
2928 Perl guesses a reasonable buffer size, but puts a sentinel byte at the
2929 end of the buffer just in case. This sentinel byte got clobbered, and
2930 Perl assumes that memory is now corrupted. See L<perlfunc/ioctl>.
2932 =item Possible unintended interpolation of %s in string
2934 (W ambiguous) You said something like `@foo' in a double-quoted string
2935 but there was no array C<@foo> in scope at the time. If you wanted a
2936 literal @foo, then write it as \@foo; otherwise find out what happened
2937 to the array you apparently lost track of.
2939 =item Possible Y2K bug: %s
2941 (W y2k) You are concatenating the number 19 with another number, which
2942 could be a potential Year 2000 problem.
2944 =item pragma "attrs" is deprecated, use "sub NAME : ATTRS" instead
2946 (D deprecated) You have written something like this:
2950 use attrs qw(locked);
2953 You should use the new declaration syntax instead.
2959 The C<use attrs> pragma is now obsolete, and is only provided for
2960 backward-compatibility. See L<perlsub/"Subroutine Attributes">.
2962 =item Precedence problem: open %s should be open(%s)
2964 (S precedence) The old irregular construct
2968 is now misinterpreted as
2972 because of the strict regularization of Perl 5's grammar into unary and
2973 list operators. (The old open was a little of both.) You must put
2974 parentheses around the filehandle, or use the new "or" operator instead
2977 =item Premature end of script headers
2981 =item printf() on closed filehandle %s
2983 (W closed) The filehandle you're writing to got itself closed sometime
2984 before now. Check your control flow.
2986 =item print() on closed filehandle %s
2988 (W closed) The filehandle you're printing on got itself closed sometime
2989 before now. Check your control flow.
2991 =item Process terminated by SIG%s
2993 (W) This is a standard message issued by OS/2 applications, while *nix
2994 applications die in silence. It is considered a feature of the OS/2
2995 port. One can easily disable this by appropriate sighandlers, see
2996 L<perlipc/"Signals">. See also "Process terminated by SIGTERM/SIGINT"
2999 =item Prototype mismatch: %s vs %s
3001 (S prototype) The subroutine being declared or defined had previously been
3002 declared or defined with a different function prototype.
3004 =item Prototype not terminated
3006 (F) You've omitted the closing parenthesis in a function prototype
3009 =item Quantifier in {,} bigger than %d in regex;
3011 marked by <-- HERE in m/%s/
3013 (F) There is currently a limit to the size of the min and max values of the
3014 {min,max} construct. The <-- HERE shows in the regular expression about where
3015 the problem was discovered. See L<perlre>.
3017 =item Quantifier unexpected on zero-length expression;
3019 marked by <-- HERE in m/%s/
3021 (W regexp) You applied a regular expression quantifier in a place where
3022 it makes no sense, such as on a zero-width assertion. Try putting the
3023 quantifier inside the assertion instead. For example, the way to match
3024 "abc" provided that it is followed by three repetitions of "xyz" is
3025 C</abc(?=(?:xyz){3})/>, not C</abc(?=xyz){3}/>.
3027 The <-- HERE shows in the regular expression about where the problem was
3030 =item Range iterator outside integer range
3032 (F) One (or both) of the numeric arguments to the range operator ".."
3033 are outside the range which can be represented by integers internally.
3034 One possible workaround is to force Perl to use magical string increment
3035 by prepending "0" to your numbers.
3037 =item readline() on closed filehandle %s
3039 (W closed) The filehandle you're reading from got itself closed sometime
3040 before now. Check your control flow.
3042 =item Reallocation too large: %lx
3044 (F) You can't allocate more than 64K on an MS-DOS machine.
3046 =item realloc() of freed memory ignored
3048 (S malloc) An internal routine called realloc() on something that had
3051 =item Recompile perl with B<-D>DEBUGGING to use B<-D> switch
3053 (F debugging) You can't use the B<-D> option unless the code to produce
3054 the desired output is compiled into Perl, which entails some overhead,
3055 which is why it's currently left out of your copy.
3057 =item Recursive inheritance detected in package '%s'
3059 (F) More than 100 levels of inheritance were used. Probably indicates
3060 an unintended loop in your inheritance hierarchy.
3062 =item Recursive inheritance detected while looking for method %s
3064 (F) More than 100 levels of inheritance were encountered while invoking
3065 a method. Probably indicates an unintended loop in your inheritance
3068 =item Reference found where even-sized list expected
3070 (W misc) You gave a single reference where Perl was expecting a list
3071 with an even number of elements (for assignment to a hash). This usually
3072 means that you used the anon hash constructor when you meant to use
3073 parens. In any case, a hash requires key/value B<pairs>.
3075 %hash = { one => 1, two => 2, }; # WRONG
3076 %hash = [ qw/ an anon array / ]; # WRONG
3077 %hash = ( one => 1, two => 2, ); # right
3078 %hash = qw( one 1 two 2 ); # also fine
3080 =item Reference is already weak
3082 (W misc) You have attempted to weaken a reference that is already weak.
3083 Doing so has no effect.
3085 =item Reference miscount in sv_replace()
3087 (W internal) The internal sv_replace() function was handed a new SV with
3088 a reference count of other than 1.
3090 =item Reference to nonexistent group in regex;
3092 marked by <-- HERE in m/%s/
3094 (F) You used something like C<\7> in your regular expression, but there are
3095 not at least seven sets of capturing parentheses in the expression. If you
3096 wanted to have the character with value 7 inserted into the regular expression,
3097 prepend a zero to make the number at least two digits: C<\07>
3099 The <-- HERE shows in the regular expression about where the problem was
3102 =item regexp memory corruption
3104 (P) The regular expression engine got confused by what the regular
3105 expression compiler gave it.
3107 =item Regexp out of space
3109 (P) A "can't happen" error, because safemalloc() should have caught it
3112 =item Repeat count in pack overflows
3114 (F) You can't specify a repeat count so large that it overflows your
3115 signed integers. See L<perlfunc/pack>.
3117 =item Repeat count in unpack overflows
3119 (F) You can't specify a repeat count so large that it overflows your
3120 signed integers. See L<perlfunc/unpack>.
3122 =item Reversed %s= operator
3124 (W syntax) You wrote your assignment operator backwards. The = must
3125 always comes last, to avoid ambiguity with subsequent unary operators.
3127 =item Runaway format
3129 (F) Your format contained the ~~ repeat-until-blank sequence, but it
3130 produced 200 lines at once, and the 200th line looked exactly like the
3131 199th line. Apparently you didn't arrange for the arguments to exhaust
3132 themselves, either by using ^ instead of @ (for scalar variables), or by
3133 shifting or popping (for array variables). See L<perlform>.
3135 =item Scalar value @%s[%s] better written as $%s[%s]
3137 (W syntax) You've used an array slice (indicated by @) to select a
3138 single element of an array. Generally it's better to ask for a scalar
3139 value (indicated by $). The difference is that C<$foo[&bar]> always
3140 behaves like a scalar, both when assigning to it and when evaluating its
3141 argument, while C<@foo[&bar]> behaves like a list when you assign to it,
3142 and provides a list context to its subscript, which can do weird things
3143 if you're expecting only one subscript.
3145 On the other hand, if you were actually hoping to treat the array
3146 element as a list, you need to look into how references work, because
3147 Perl will not magically convert between scalars and lists for you. See
3150 =item Scalar value @%s{%s} better written as $%s{%s}
3152 (W syntax) You've used a hash slice (indicated by @) to select a single
3153 element of a hash. Generally it's better to ask for a scalar value
3154 (indicated by $). The difference is that C<$foo{&bar}> always behaves
3155 like a scalar, both when assigning to it and when evaluating its
3156 argument, while C<@foo{&bar}> behaves like a list when you assign to it,
3157 and provides a list context to its subscript, which can do weird things
3158 if you're expecting only one subscript.
3160 On the other hand, if you were actually hoping to treat the hash element
3161 as a list, you need to look into how references work, because Perl will
3162 not magically convert between scalars and lists for you. See
3165 =item Scalars leaked: %d
3167 (P) Something went wrong in Perl's internal bookkeeping of scalars:
3168 not all scalar variables were deallocated by the time Perl exited.
3169 What this usually indicates is a memory leak, which is of course bad,
3170 especially if the Perl program is intended to be long-running.
3172 =item Script is not setuid/setgid in suidperl
3174 (F) Oddly, the suidperl program was invoked on a script without a setuid
3175 or setgid bit set. This doesn't make much sense.
3177 =item Search pattern not terminated
3179 (F) The lexer couldn't find the final delimiter of a // or m{}
3180 construct. Remember that bracketing delimiters count nesting level.
3181 Missing the leading C<$> from a variable C<$m> may cause this error.
3183 =item %sseek() on unopened filehandle
3185 (W unopened) You tried to use the seek() or sysseek() function on a
3186 filehandle that was either never opened or has since been closed.
3188 =item select not implemented
3190 (F) This machine doesn't implement the select() system call.
3192 =item Self-ties of arrays and hashes are not supported
3194 (F) Self-ties are of arrays and hashes are not supported in
3195 the current implementation.
3197 =item Semicolon seems to be missing
3199 (W semicolon) A nearby syntax error was probably caused by a missing
3200 semicolon, or possibly some other missing operator, such as a comma.
3202 =item semi-panic: attempt to dup freed string
3204 (S internal) The internal newSVsv() routine was called to duplicate a
3205 scalar that had previously been marked as free.
3207 =item sem%s not implemented
3209 (F) You don't have System V semaphore IPC on your system.
3211 =item send() on closed socket %s
3213 (W closed) The socket you're sending to got itself closed sometime
3214 before now. Check your control flow.
3216 =item Sequence (? incomplete in regex; marked by <-- HERE in m/%s/
3218 (F) A regular expression ended with an incomplete extension (?. The <-- HERE
3219 shows in the regular expression about where the problem was discovered. See
3222 =item Sequence (?{...}) not terminated or not {}-balanced in regex;
3224 marked by <-- HERE in m/%s/
3226 (F) If the contents of a (?{...}) clause contains braces, they must balance
3227 for Perl to properly detect the end of the clause. The <-- HERE shows in
3228 the regular expression about where the problem was discovered. See
3231 =item Sequence (?%s...) not implemented in regex;
3233 marked by <-- HERE in m/%s/
3235 (F) A proposed regular expression extension has the character reserved but
3236 has not yet been written. The <-- HERE shows in the regular expression about
3237 where the problem was discovered. See L<perlre>.
3239 =item Sequence (?%s...) not recognized in regex;
3241 marked by <-- HERE in m/%s/
3243 (F) You used a regular expression extension that doesn't make sense. The
3244 <-- HERE shows in the regular expression about where the problem was
3245 discovered. See L<perlre>.
3247 =item Sequence (?#... not terminated in regex;
3249 marked by <-- HERE in m/%s/
3251 (F) A regular expression comment must be terminated by a closing
3252 parenthesis. Embedded parentheses aren't allowed. The <-- HERE shows in
3253 the regular expression about where the problem was discovered. See
3256 =item 500 Server error
3262 This is the error message generally seen in a browser window when trying
3263 to run a CGI program (including SSI) over the web. The actual error text
3264 varies widely from server to server. The most frequently-seen variants
3265 are "500 Server error", "Method (something) not permitted", "Document
3266 contains no data", "Premature end of script headers", and "Did not
3267 produce a valid header".
3269 B<This is a CGI error, not a Perl error>.
3271 You need to make sure your script is executable, is accessible by the
3272 user CGI is running the script under (which is probably not the user
3273 account you tested it under), does not rely on any environment variables
3274 (like PATH) from the user it isn't running under, and isn't in a
3275 location where the CGI server can't find it, basically, more or less.
3276 Please see the following for more information:
3278 http://www.perl.org/CGI_MetaFAQ.html
3279 http://www.htmlhelp.org/faq/cgifaq.html
3280 http://www.w3.org/Security/Faq/
3282 You should also look at L<perlfaq9>.
3284 =item setegid() not implemented
3286 (F) You tried to assign to C<$)>, and your operating system doesn't
3287 support the setegid() system call (or equivalent), or at least Configure
3290 =item seteuid() not implemented
3292 (F) You tried to assign to C<< $> >>, and your operating system doesn't
3293 support the seteuid() system call (or equivalent), or at least Configure
3296 =item setpgrp can't take arguments
3298 (F) Your system has the setpgrp() from BSD 4.2, which takes no
3299 arguments, unlike POSIX setpgid(), which takes a process ID and process
3302 =item setrgid() not implemented
3304 (F) You tried to assign to C<$(>, and your operating system doesn't
3305 support the setrgid() system call (or equivalent), or at least Configure
3308 =item setruid() not implemented
3310 (F) You tried to assign to C<$<>, and your operating system doesn't
3311 support the setruid() system call (or equivalent), or at least Configure
3314 =item setsockopt() on closed socket %s
3316 (W closed) You tried to set a socket option on a closed socket. Did you
3317 forget to check the return value of your socket() call? See
3318 L<perlfunc/setsockopt>.
3320 =item Setuid/gid script is writable by world
3322 (F) The setuid emulator won't run a script that is writable by the
3323 world, because the world might have written on it already.
3325 =item shm%s not implemented
3327 (F) You don't have System V shared memory IPC on your system.
3329 =item <> should be quotes
3331 (F) You wrote C<< require <file> >> when you should have written
3334 =item /%s/ should probably be written as "%s"
3336 (W syntax) You have used a pattern where Perl expected to find a string,
3337 as in the first argument to C<join>. Perl will treat the true or false
3338 result of matching the pattern against $_ as the string, which is
3339 probably not what you had in mind.
3341 =item shutdown() on closed socket %s
3343 (W closed) You tried to do a shutdown on a closed socket. Seems a bit
3346 =item SIG%s handler "%s" not defined
3348 (W signal) The signal handler named in %SIG doesn't, in fact, exist.
3349 Perhaps you put it into the wrong package?
3351 =item sort is now a reserved word
3353 (F) An ancient error message that almost nobody ever runs into anymore.
3354 But before sort was a keyword, people sometimes used it as a filehandle.
3356 =item Sort subroutine didn't return a numeric value
3358 (F) A sort comparison routine must return a number. You probably blew
3359 it by not using C<< <=> >> or C<cmp>, or by not using them correctly.
3360 See L<perlfunc/sort>.
3362 =item Sort subroutine didn't return single value
3364 (F) A sort comparison subroutine may not return a list value with more
3365 or less than one element. See L<perlfunc/sort>.
3367 =item splice() offset past end of array
3369 (W misc) You attempted to specify an offset that was past the end of
3370 the array passed to splice(). Splicing will instead commence at the end
3371 of the array, rather than past it. If this isn't what you want, try
3372 explicitly pre-extending the array by assigning $#array = $offset. See
3377 (P) The split was looping infinitely. (Obviously, a split shouldn't
3378 iterate more times than there are characters of input, which is what
3379 happened.) See L<perlfunc/split>.
3381 =item Statement unlikely to be reached
3383 (W exec) You did an exec() with some statement after it other than a
3384 die(). This is almost always an error, because exec() never returns
3385 unless there was a failure. You probably wanted to use system()
3386 instead, which does return. To suppress this warning, put the exec() in
3389 =item stat() on unopened filehandle %s
3391 (W unopened) You tried to use the stat() function on a filehandle that
3392 was either never opened or has since been closed.
3394 =item Stub found while resolving method `%s' overloading %s
3396 (P) Overloading resolution over @ISA tree may be broken by importation
3397 stubs. Stubs should never be implicitly created, but explicit calls to
3398 C<can> may break this.
3400 =item Subroutine %s redefined
3402 (W redefine) You redefined a subroutine. To suppress this warning, say
3405 no warnings 'redefine';
3406 eval "sub name { ... }";
3409 =item Substitution loop
3411 (P) The substitution was looping infinitely. (Obviously, a substitution
3412 shouldn't iterate more times than there are characters of input, which
3413 is what happened.) See the discussion of substitution in
3414 L<perlop/"Quote and Quote-like Operators">.
3416 =item Substitution pattern not terminated
3418 (F) The lexer couldn't find the interior delimiter of an s/// or s{}{}
3419 construct. Remember that bracketing delimiters count nesting level.
3420 Missing the leading C<$> from variable C<$s> may cause this error.
3422 =item Substitution replacement not terminated
3424 (F) The lexer couldn't find the final delimiter of an s/// or s{}{}
3425 construct. Remember that bracketing delimiters count nesting level.
3426 Missing the leading C<$> from variable C<$s> may cause this error.
3428 =item substr outside of string
3430 (W substr),(F) You tried to reference a substr() that pointed outside of
3431 a string. That is, the absolute value of the offset was larger than the
3432 length of the string. See L<perlfunc/substr>. This warning is fatal if
3433 substr is used in an lvalue context (as the left hand side of an
3434 assignment or as a subroutine argument for example).
3436 =item suidperl is no longer needed since %s
3438 (F) Your Perl was compiled with B<-D>SETUID_SCRIPTS_ARE_SECURE_NOW, but
3439 a version of the setuid emulator somehow got run anyway.
3441 =item Switch (?(condition)... contains too many branches in regex;
3443 marked by <-- HERE in m/%s/
3445 (F) A (?(condition)if-clause|else-clause) construct can have at most two
3446 branches (the if-clause and the else-clause). If you want one or both to
3447 contain alternation, such as using C<this|that|other>, enclose it in
3448 clustering parentheses:
3450 (?(condition)(?:this|that|other)|else-clause)
3452 The <-- HERE shows in the regular expression about where the problem was
3453 discovered. See L<perlre>.
3455 =item Switch condition not recognized in regex;
3457 marked by <-- HERE in m/%s/
3459 (F) If the argument to the (?(...)if-clause|else-clause) construct is a
3460 number, it can be only a number. The <-- HERE shows in the regular expression
3461 about where the problem was discovered. See L<perlre>.
3463 =item switching effective %s is not implemented
3465 (F) While under the C<use filetest> pragma, we cannot switch the real
3466 and effective uids or gids.
3470 (F) Probably means you had a syntax error. Common reasons include:
3472 A keyword is misspelled.
3473 A semicolon is missing.
3475 An opening or closing parenthesis is missing.
3476 An opening or closing brace is missing.
3477 A closing quote is missing.
3479 Often there will be another error message associated with the syntax
3480 error giving more information. (Sometimes it helps to turn on B<-w>.)
3481 The error message itself often tells you where it was in the line when
3482 it decided to give up. Sometimes the actual error is several tokens
3483 before this, because Perl is good at understanding random input.
3484 Occasionally the line number may be misleading, and once in a blue moon
3485 the only way to figure out what's triggering the error is to call
3486 C<perl -c> repeatedly, chopping away half the program each time to see
3487 if the error went away. Sort of the cybernetic version of S<20
3490 =item syntax error at line %d: `%s' unexpected
3492 (A) You've accidentally run your script through the Bourne shell instead
3493 of Perl. Check the #! line, or manually feed your script into Perl
3496 =item syntax error in file %s at line %d, next 2 tokens "%s"
3498 (F) This error is likely to occur if you run a perl5 script through
3499 a perl4 interpreter, especially if the next 2 tokens are "use strict"
3500 or "my $var" or "our $var".
3504 (F) The final summary message when a C<perl -c> succeeds.
3506 =item System V %s is not implemented on this machine
3508 (F) You tried to do something with a function beginning with "sem",
3509 "shm", or "msg" but that System V IPC is not implemented in your
3510 machine. In some machines the functionality can exist but be
3511 unconfigured. Consult your system support.
3513 =item syswrite() on closed filehandle %s
3515 (W closed) The filehandle you're writing to got itself closed sometime
3516 before now. Check your control flow.
3518 =item Target of goto is too deeply nested
3520 (F) You tried to use C<goto> to reach a label that was too deeply nested
3521 for Perl to reach. Perl is doing you a favor by refusing.
3523 =item tell() on unopened filehandle
3525 (W unopened) You tried to use the tell() function on a filehandle that
3526 was either never opened or has since been closed.
3528 =item That use of $[ is unsupported
3530 (F) Assignment to C<$[> is now strictly circumscribed, and interpreted
3531 as a compiler directive. You may say only one of
3540 This is to prevent the problem of one module changing the array base out
3541 from under another module inadvertently. See L<perlvar/$[>.
3543 =item The crypt() function is unimplemented due to excessive paranoia
3545 (F) Configure couldn't find the crypt() function on your machine,
3546 probably because your vendor didn't supply it, probably because they
3547 think the U.S. Government thinks it's a secret, or at least that they
3548 will continue to pretend that it is. And if you quote me on that, I
3551 =item The %s function is unimplemented
3553 The function indicated isn't implemented on this architecture, according
3554 to the probings of Configure.
3556 =item The stat preceding %s wasn't an lstat
3558 (F) It makes no sense to test the current stat buffer for symbolic
3559 linkhood if the last stat that wrote to the stat buffer already went
3560 past the symlink to get to the real file. Use an actual filename
3563 =item This Perl can't reset CRTL environ elements (%s)
3565 =item This Perl can't set CRTL environ elements (%s=%s)
3567 (W internal) Warnings peculiar to VMS. You tried to change or delete an
3568 element of the CRTL's internal environ array, but your copy of Perl
3569 wasn't built with a CRTL that contained the setenv() function. You'll
3570 need to rebuild Perl with a CRTL that does, or redefine
3571 F<PERL_ENV_TABLES> (see L<perlvms>) so that the environ array isn't the
3572 target of the change to
3573 %ENV which produced the warning.
3575 =item thread failed to start: %s
3577 (F) The entry point function of threads->create() failed for some reason.
3579 =item times not implemented
3581 (F) Your version of the C library apparently doesn't do times(). I
3582 suspect you're not running on Unix.
3584 =item Too few args to syscall
3586 (F) There has to be at least one argument to syscall() to specify the
3587 system call to call, silly dilly.
3589 =item Too late for "B<-T>" option
3591 (X) The #! line (or local equivalent) in a Perl script contains the
3592 B<-T> option, but Perl was not invoked with B<-T> in its command line.
3593 This is an error because, by the time Perl discovers a B<-T> in a
3594 script, it's too late to properly taint everything from the environment.
3597 If the Perl script is being executed as a command using the #!
3598 mechanism (or its local equivalent), this error can usually be fixed by
3599 editing the #! line so that the B<-T> option is a part of Perl's first
3600 argument: e.g. change C<perl -n -T> to C<perl -T -n>.
3602 If the Perl script is being executed as C<perl scriptname>, then the
3603 B<-T> option must appear on the command line: C<perl -T scriptname>.
3605 =item Too late for "-%s" option
3607 (X) The #! line (or local equivalent) in a Perl script contains the
3608 B<-M> or B<-m> option. This is an error because B<-M> and B<-m> options
3609 are not intended for use inside scripts. Use the C<use> pragma instead.
3611 =item Too late to run %s block
3613 (W void) A CHECK or INIT block is being defined during run time proper,
3614 when the opportunity to run them has already passed. Perhaps you are
3615 loading a file with C<require> or C<do> when you should be using C<use>
3616 instead. Or perhaps you should put the C<require> or C<do> inside a
3619 =item Too many args to syscall
3621 (F) Perl supports a maximum of only 14 args to syscall().
3623 =item Too many arguments for %s
3625 (F) The function requires fewer arguments than you specified.
3631 (A) You've accidentally run your script through B<csh> instead of Perl.
3632 Check the #! line, or manually feed your script into Perl yourself.
3634 =item Trailing \ in regex m/%s/
3636 (F) The regular expression ends with an unbackslashed backslash.
3637 Backslash it. See L<perlre>.
3639 =item Transliteration pattern not terminated
3641 (F) The lexer couldn't find the interior delimiter of a tr/// or tr[][]
3642 or y/// or y[][] construct. Missing the leading C<$> from variables
3643 C<$tr> or C<$y> may cause this error.
3645 =item Transliteration replacement not terminated
3647 (F) The lexer couldn't find the final delimiter of a tr/// or tr[][]
3650 =item truncate not implemented
3652 (F) Your machine doesn't implement a file truncation mechanism that
3653 Configure knows about.
3655 =item Type of arg %d to %s must be %s (not %s)
3657 (F) This function requires the argument in that position to be of a
3658 certain type. Arrays must be @NAME or C<@{EXPR}>. Hashes must be
3659 %NAME or C<%{EXPR}>. No implicit dereferencing is allowed--use the
3660 {EXPR} forms as an explicit dereference. See L<perlref>.
3662 =item umask not implemented
3664 (F) Your machine doesn't implement the umask function and you tried to
3665 use it to restrict permissions for yourself (EXPR & 0700).
3667 =item Unable to create sub named "%s"
3669 (F) You attempted to create or access a subroutine with an illegal name.
3671 =item Unbalanced context: %d more PUSHes than POPs
3673 (W internal) The exit code detected an internal inconsistency in how
3674 many execution contexts were entered and left.
3676 =item Unbalanced saves: %d more saves than restores
3678 (W internal) The exit code detected an internal inconsistency in how
3679 many values were temporarily localized.
3681 =item Unbalanced scopes: %d more ENTERs than LEAVEs
3683 (W internal) The exit code detected an internal inconsistency in how
3684 many blocks were entered and left.
3686 =item Unbalanced tmps: %d more allocs than frees
3688 (W internal) The exit code detected an internal inconsistency in how
3689 many mortal scalars were allocated and freed.
3691 =item Undefined format "%s" called
3693 (F) The format indicated doesn't seem to exist. Perhaps it's really in
3694 another package? See L<perlform>.
3696 =item Undefined sort subroutine "%s" called
3698 (F) The sort comparison routine specified doesn't seem to exist.
3699 Perhaps it's in a different package? See L<perlfunc/sort>.
3701 =item Undefined subroutine &%s called
3703 (F) The subroutine indicated hasn't been defined, or if it was, it has
3704 since been undefined.
3706 =item Undefined subroutine called
3708 (F) The anonymous subroutine you're trying to call hasn't been defined,
3709 or if it was, it has since been undefined.
3711 =item Undefined subroutine in sort
3713 (F) The sort comparison routine specified is declared but doesn't seem
3714 to have been defined yet. See L<perlfunc/sort>.
3716 =item Undefined top format "%s" called
3718 (F) The format indicated doesn't seem to exist. Perhaps it's really in
3719 another package? See L<perlform>.
3721 =item Undefined value assigned to typeglob
3723 (W misc) An undefined value was assigned to a typeglob, a la
3724 C<*foo = undef>. This does nothing. It's possible that you really mean
3727 =item %s: Undefined variable
3729 (A) You've accidentally run your script through B<csh> instead of Perl.
3730 Check the #! line, or manually feed your script into Perl yourself.
3732 =item unexec of %s into %s failed!
3734 (F) The unexec() routine failed for some reason. See your local FSF
3735 representative, who probably put it there in the first place.
3737 =item Unicode character %s is illegal
3739 (W utf8) Certain Unicode characters have been designated off-limits by
3740 the Unicode standard and should not be generated. If you really know
3741 what you are doing you can turn off this warning by C<no warnings 'utf8';>.
3743 =item Unknown BYTEORDER
3745 (F) There are no byte-swapping functions for a machine with this byte
3748 =item Unknown "re" subpragma '%s' (known ones are: %s)
3750 You tried to use an unknown subpragma of the "re" pragma.
3752 =item Unknown switch condition (?(%.2s in regex;
3754 marked by <-- HERE in m/%s/
3756 (F) The condition part of a (?(condition)if-clause|else-clause) construct
3757 is not known. The condition may be lookahead or lookbehind (the condition
3758 is true if the lookahead or lookbehind is true), a (?{...}) construct (the
3759 condition is true if the code evaluates to a true value), or a number (the
3760 condition is true if the set of capturing parentheses named by the number
3763 The <-- HERE shows in the regular expression about where the problem was
3764 discovered. See L<perlre>.
3766 =item Unknown open() mode '%s'
3768 (F) The second argument of 3-argument open() is not among the list
3769 of valid modes: C<< < >>, C<< > >>, C<<< >> >>>, C<< +< >>,
3770 C<< +> >>, C<<< +>> >>>, C<-|>, C<|->, C<< <& >>, C<< >& >>.
3772 =item Unknown process %x sent message to prime_env_iter: %s
3774 (P) An error peculiar to VMS. Perl was reading values for %ENV before
3775 iterating over it, and someone else stuck a message in the stream of
3776 data Perl expected. Someone's very confused, or perhaps trying to
3777 subvert Perl's population of %ENV for nefarious purposes.
3779 =item Unknown warnings category '%s'
3781 (F) An error issued by the C<warnings> pragma. You specified a warnings
3782 category that is unknown to perl at this point.
3784 Note that if you want to enable a warnings category registered by a module
3785 (e.g. C<use warnings 'File::Find'>), you must have imported this module
3788 =item unmatched [ in regex; marked by <-- HERE in m/%s/
3790 (F) The brackets around a character class must match. If you wish to
3791 include a closing bracket in a character class, backslash it or put it
3792 first. The <-- HERE shows in the regular expression about where the problem
3793 was discovered. See L<perlre>.
3795 =item unmatched ( in regex; marked by <-- HERE in m/%s/
3797 (F) Unbackslashed parentheses must always be balanced in regular
3798 expressions. If you're a vi user, the % key is valuable for finding the
3799 matching parenthesis. The <-- HERE shows in the regular expression about
3800 where the problem was discovered. See L<perlre>.
3802 =item Unmatched right %s bracket
3804 (F) The lexer counted more closing curly or square brackets than opening
3805 ones, so you're probably missing a matching opening bracket. As a
3806 general rule, you'll find the missing one (so to speak) near the place
3807 you were last editing.
3809 =item Unquoted string "%s" may clash with future reserved word
3811 (W reserved) You used a bareword that might someday be claimed as a
3812 reserved word. It's best to put such a word in quotes, or capitalize it
3813 somehow, or insert an underbar into it. You might also declare it as a
3816 =item Unrecognized character %s
3818 (F) The Perl parser has no idea what to do with the specified character
3819 in your Perl script (or eval). Perhaps you tried to run a compressed
3820 script, a binary program, or a directory as a Perl program.
3822 =item /%s/: Unrecognized escape \\%c in character class passed through
3824 (W regexp) You used a backslash-character combination which is not
3825 recognized by Perl inside character classes. The character was
3826 understood literally.
3828 =item Unrecognized escape \\%c passed through in regex;
3830 marked by <-- HERE in m/%s/
3832 (W regexp) You used a backslash-character combination which is not
3833 recognized by Perl. This combination appears in an interpolated variable or
3834 a C<'>-delimited regular expression. The character was understood
3835 literally. The <-- HERE shows in the regular expression about where the
3836 escape was discovered.
3838 =item Unrecognized escape \\%c passed through
3840 (W misc) You used a backslash-character combination which is not
3843 =item Unrecognized signal name "%s"
3845 (F) You specified a signal name to the kill() function that was not
3846 recognized. Say C<kill -l> in your shell to see the valid signal names
3849 =item Unrecognized switch: -%s (-h will show valid options)
3851 (F) You specified an illegal option to Perl. Don't do that. (If you
3852 think you didn't do that, check the #! line to see if it's supplying the
3853 bad switch on your behalf.)
3855 =item Unsuccessful %s on filename containing newline
3857 (W newline) A file operation was attempted on a filename, and that
3858 operation failed, PROBABLY because the filename contained a newline,
3859 PROBABLY because you forgot to chomp() it off. See L<perlfunc/chomp>.
3861 =item Unsupported directory function "%s" called
3863 (F) Your machine doesn't support opendir() and readdir().
3865 =item Unsupported function %s
3867 (F) This machine doesn't implement the indicated function, apparently.
3868 At least, Configure doesn't think so.
3870 =item Unsupported function fork
3872 (F) Your version of executable does not support forking.
3874 Note that under some systems, like OS/2, there may be different flavors
3875 of Perl executables, some of which may support fork, some not. Try
3876 changing the name you call Perl by to C<perl_>, C<perl__>, and so on.
3878 =item Unsupported script encoding
3880 (F) Your program file begins with a Unicode Byte Order Mark (BOM) which
3881 declares it to be in a Unicode encoding that Perl cannot yet read.
3883 =item Unsupported socket function "%s" called
3885 (F) Your machine doesn't support the Berkeley socket mechanism, or at
3886 least that's what Configure thought.
3888 =item Unterminated attribute list
3890 (F) The lexer found something other than a simple identifier at the
3891 start of an attribute, and it wasn't a semicolon or the start of a
3892 block. Perhaps you terminated the parameter list of the previous
3893 attribute too soon. See L<attributes>.
3895 =item Unterminated attribute parameter in attribute list
3897 (F) The lexer saw an opening (left) parenthesis character while parsing
3898 an attribute list, but the matching closing (right) parenthesis
3899 character was not found. You may need to add (or remove) a backslash
3900 character to get your parentheses to balance. See L<attributes>.
3902 =item Unterminated compressed integer
3904 (F) An argument to unpack("w",...) was incompatible with the BER
3905 compressed integer format and could not be converted to an integer.
3906 See L<perlfunc/pack>.
3908 =item Unterminated <> operator
3910 (F) The lexer saw a left angle bracket in a place where it was expecting
3911 a term, so it's looking for the corresponding right angle bracket, and
3912 not finding it. Chances are you left some needed parentheses out
3913 earlier in the line, and you really meant a "less than".
3915 =item untie attempted while %d inner references still exist
3917 (W untie) A copy of the object returned from C<tie> (or C<tied>) was
3918 still valid when C<untie> was called.
3920 =item Useless (?%s) - use /%s modifier in regex;
3922 marked by <-- HERE in m/%s/
3924 (W regexp) You have used an internal modifier such as (?o) that has no
3925 meaning unless applied to the entire regexp:
3927 if ($string =~ /(?o)$pattern/) { ... }
3931 if ($string =~ /$pattern/o) { ... }
3933 The <-- HERE shows in the regular expression about
3934 where the problem was discovered. See L<perlre>.
3936 =item Useless (?-%s) - don't use /%s modifier in regex;
3938 marked by <-- HERE in m/%s/
3940 (W regexp) You have used an internal modifier such as (?-o) that has no
3941 meaning unless removed from the entire regexp:
3943 if ($string =~ /(?-o)$pattern/o) { ... }
3947 if ($string =~ /$pattern/) { ... }
3949 The <-- HERE shows in the regular expression about
3950 where the problem was discovered. See L<perlre>.
3952 =item Useless use of %s in void context
3954 (W void) You did something without a side effect in a context that does
3955 nothing with the return value, such as a statement that doesn't return a
3956 value from a block, or the left side of a scalar comma operator. Very
3957 often this points not to stupidity on your part, but a failure of Perl
3958 to parse your program the way you thought it would. For example, you'd
3959 get this if you mixed up your C precedence with Python precedence and
3964 when you meant to say
3966 ($one, $two) = (1, 2);
3968 Another common error is to use ordinary parentheses to construct a list
3969 reference when you should be using square or curly brackets, for
3974 when you should have said
3978 The square brackets explicitly turn a list value into a scalar value,
3979 while parentheses do not. So when a parenthesized list is evaluated in
3980 a scalar context, the comma is treated like C's comma operator, which
3981 throws away the left argument, which is not what you want. See
3982 L<perlref> for more on this.
3984 This warning will not be issued for numerical constants equal to 0 or 1
3985 since they are often used in statements like
3987 1 while sub_with_side_effects() ;
3989 String constants that would normally evaluate to 0 or 1 are warned
3992 =item Useless use of "re" pragma
3994 (W) You did C<use re;> without any arguments. That isn't very useful.
3996 =item Useless use of sort in scalar context
3998 (W void) You used sort in scalar context, as in :
4002 This is not very useful, and perl currently optimizes this away.
4004 =item Useless use of %s with no values
4006 (W syntax) You used the push() or unshift() function with no arguments
4007 apart from the array, like C<push(@x)> or C<unshift(@foo)>. That won't
4008 usually have any effect on the array, so is completely useless. It's
4009 possible in principle that push(@tied_array) could have some effect
4010 if the array is tied to a class which implements a PUSH method. If so,
4011 you can write it as C<push(@tied_array,())> to avoid this warning.
4013 =item "use" not allowed in expression
4015 (F) The "use" keyword is recognized and executed at compile time, and
4016 returns no useful value. See L<perlmod>.
4018 =item Use of bare << to mean <<"" is deprecated
4020 (D deprecated) You are now encouraged to use the explicitly quoted form
4021 if you wish to use an empty line as the terminator of the here-document.
4023 =item Use of /c modifier is meaningless in s///
4025 (W regexp) You used the /c modifier in a substitution. The /c
4026 modifier is not presently meaningful in substitutions.
4028 =item Use of /c modifier is meaningless without /g
4030 (W regexp) You used the /c modifier with a regex operand, but didn't
4031 use the /g modifier. Currently, /c is meaningful only when /g is
4032 used. (This may change in the future.)
4034 =item Use of /g modifier is meaningless in split
4036 (W regexp) You used the /g modifier on the pattern for a C<split>
4037 operator. Since C<split> always tries to match the pattern
4038 repeatedly, the C</g> has no effect.
4040 =item Use of *glob{FILEHANDLE} is deprecated
4042 (D deprecated) You are now encouraged to use the shorter *glob{IO} form
4043 to access the filehandle slot within a typeglob.
4045 =item Use of chdir('') or chdir(undef) as chdir() deprecated
4047 (D deprecated) chdir() with no arguments is documented to change to
4048 $ENV{HOME} or $ENV{LOGDIR}. chdir(undef) and chdir('') share this
4049 behavior, but that has been deprecated. In future versions they
4052 Be careful to check that what you pass to chdir() is defined and not
4053 blank, else you might find yourself in your home directory.
4055 =item Use of implicit split to @_ is deprecated
4057 (D deprecated) It makes a lot of work for the compiler when you clobber
4058 a subroutine's argument list, so it's better if you assign the results
4059 of a split() explicitly to an array (or list).
4061 =item Use of inherited AUTOLOAD for non-method %s() is deprecated
4063 (D deprecated) As an (ahem) accidental feature, C<AUTOLOAD> subroutines
4064 are looked up as methods (using the C<@ISA> hierarchy) even when the
4065 subroutines to be autoloaded were called as plain functions (e.g.
4066 C<Foo::bar()>), not as methods (e.g. C<< Foo->bar() >> or C<<
4069 This bug will be rectified in future by using method lookup only for
4070 methods' C<AUTOLOAD>s. However, there is a significant base of existing
4071 code that may be using the old behavior. So, as an interim step, Perl
4072 currently issues an optional warning when non-methods use inherited
4075 The simple rule is: Inheritance will not work when autoloading
4076 non-methods. The simple fix for old code is: In any module that used
4077 to depend on inheriting C<AUTOLOAD> for non-methods from a base class
4078 named C<BaseClass>, execute C<*AUTOLOAD = \&BaseClass::AUTOLOAD> during
4081 In code that currently says C<use AutoLoader; @ISA = qw(AutoLoader);>
4082 you should remove AutoLoader from @ISA and change C<use AutoLoader;> to
4083 C<use AutoLoader 'AUTOLOAD';>.
4085 =item Use of -l on filehandle %s
4087 (W io) A filehandle represents an opened file, and when you opened the file
4088 it already went past any symlink you are presumably trying to look for.
4089 The operation returned C<undef>. Use a filename instead.
4091 =item Use of "package" with no arguments is deprecated
4093 (D deprecated) You used the C<package> keyword without specifying a package
4094 name. So no namespace is current at all. Using this can cause many
4095 otherwise reasonable constructs to fail in baffling ways. C<use strict;>
4098 =item Use of %s in printf format not supported
4100 (F) You attempted to use a feature of printf that is accessible from
4101 only C. This usually means there's a better way to do it in Perl.
4103 =item Use of $* is deprecated
4105 (D deprecated) This variable magically turned on multi-line pattern
4106 matching, both for you and for any luckless subroutine that you happen
4107 to call. You should use the new C<//m> and C<//s> modifiers now to do
4108 that without the dangerous action-at-a-distance effects of C<$*>.
4110 =item Use of %s is deprecated
4112 (D deprecated) The construct indicated is no longer recommended for use,
4113 generally because there's a better way to do it, and also because the
4114 old way has bad side effects.
4116 =item Use of $# is deprecated
4118 (D deprecated) This was an ill-advised attempt to emulate a poorly
4119 defined B<awk> feature. Use an explicit printf() or sprintf() instead.
4121 =item Use of reference "%s" as array index
4123 (W misc) You tried to use a reference as an array index; this probably
4124 isn't what you mean, because references in numerical context tend
4125 to be huge numbers, and so usually indicates programmer error.
4127 If you really do mean it, explicitly numify your reference, like so:
4128 C<$array[0+$ref]>. This warning is not given for overloaded objects,
4129 either, because you can overload the numification and stringification
4130 operators and then you assumedly know what you are doing.
4132 =item Use of reserved word "%s" is deprecated
4134 (D deprecated) The indicated bareword is a reserved word. Future
4135 versions of perl may use it as a keyword, so you're better off either
4136 explicitly quoting the word in a manner appropriate for its context of
4137 use, or using a different name altogether. The warning can be
4138 suppressed for subroutine names by either adding a C<&> prefix, or using
4139 a package qualifier, e.g. C<&our()>, or C<Foo::our()>.
4141 =item Use of tainted arguments in %s is deprecated
4143 (W taint, deprecated) You have supplied C<system()> or C<exec()> with multiple
4144 arguments and at least one of them is tainted. This used to be allowed
4145 but will become a fatal error in a future version of perl. Untaint your
4146 arguments. See L<perlsec>.
4148 =item Use of uninitialized value%s
4150 (W uninitialized) An undefined value was used as if it were already
4151 defined. It was interpreted as a "" or a 0, but maybe it was a mistake.
4152 To suppress this warning assign a defined value to your variables.
4154 To help you figure out what was undefined, perl tells you what operation
4155 you used the undefined value in. Note, however, that perl optimizes your
4156 program and the operation displayed in the warning may not necessarily
4157 appear literally in your program. For example, C<"that $foo"> is
4158 usually optimized into C<"that " . $foo>, and the warning will refer to
4159 the C<concatenation (.)> operator, even though there is no C<.> in your
4162 =item Using a hash as a reference is deprecated
4164 (D deprecated) You tried to use a hash as a reference, as in
4165 C<< %foo->{"bar"} >> or C<< %$ref->{"hello"} >>. Versions of perl <= 5.6.1
4166 used to allow this syntax, but shouldn't have. It is now deprecated, and will
4167 be removed in a future version.
4169 =item Using an array as a reference is deprecated
4171 (D deprecated) You tried to use an array as a reference, as in
4172 C<< @foo->[23] >> or C<< @$ref->[99] >>. Versions of perl <= 5.6.1 used to
4173 allow this syntax, but shouldn't have. It is now deprecated, and will be
4174 removed in a future version.
4176 =item UTF-16 surrogate %s
4178 (W utf8) You tried to generate half of an UTF-16 surrogate by
4179 requesting a Unicode character between the code points 0xD800 and
4180 0xDFFF (inclusive). That range is reserved exclusively for the use of
4181 UTF-16 encoding (by having two 16-bit UCS-2 characters); but Perl
4182 encodes its characters in UTF-8, so what you got is a very illegal
4183 character. If you really know what you are doing you can turn off
4184 this warning by C<no warnings 'utf8';>.
4186 =item Value of %s can be "0"; test with defined()
4188 (W misc) In a conditional expression, you used <HANDLE>, <*> (glob),
4189 C<each()>, or C<readdir()> as a boolean value. Each of these constructs
4190 can return a value of "0"; that would make the conditional expression
4191 false, which is probably not what you intended. When using these
4192 constructs in conditional expressions, test their values with the
4193 C<defined> operator.
4195 =item Value of CLI symbol "%s" too long
4197 (W misc) A warning peculiar to VMS. Perl tried to read the value of an
4198 %ENV element from a CLI symbol table, and found a resultant string
4199 longer than 1024 characters. The return value has been truncated to
4202 =item Variable "%s" is not imported%s
4204 (F) While "use strict" in effect, you referred to a global variable that
4205 you apparently thought was imported from another module, because
4206 something else of the same name (usually a subroutine) is exported by
4207 that module. It usually means you put the wrong funny character on the
4208 front of your variable.
4210 =item "%s" variable %s masks earlier declaration in same %s
4212 (W misc) A "my" or "our" variable has been redeclared in the current
4213 scope or statement, effectively eliminating all access to the previous
4214 instance. This is almost always a typographical error. Note that the
4215 earlier variable will still exist until the end of the scope or until
4216 all closure referents to it are destroyed.
4218 =item Variable "%s" may be unavailable
4220 (W closure) An inner (nested) I<anonymous> subroutine is inside a
4221 I<named> subroutine, and outside that is another subroutine; and the
4222 anonymous (innermost) subroutine is referencing a lexical variable
4223 defined in the outermost subroutine. For example:
4225 sub outermost { my $a; sub middle { sub { $a } } }
4227 If the anonymous subroutine is called or referenced (directly or
4228 indirectly) from the outermost subroutine, it will share the variable as
4229 you would expect. But if the anonymous subroutine is called or
4230 referenced when the outermost subroutine is not active, it will see the
4231 value of the shared variable as it was before and during the *first*
4232 call to the outermost subroutine, which is probably not what you want.
4234 In these circumstances, it is usually best to make the middle subroutine
4235 anonymous, using the C<sub {}> syntax. Perl has specific support for
4236 shared variables in nested anonymous subroutines; a named subroutine in
4237 between interferes with this feature.
4239 =item Variable syntax
4241 (A) You've accidentally run your script through B<csh> instead
4242 of Perl. Check the #! line, or manually feed your script into
4245 =item Variable "%s" will not stay shared
4247 (W closure) An inner (nested) I<named> subroutine is referencing a
4248 lexical variable defined in an outer subroutine.
4250 When the inner subroutine is called, it will probably see the value of
4251 the outer subroutine's variable as it was before and during the *first*
4252 call to the outer subroutine; in this case, after the first call to the
4253 outer subroutine is complete, the inner and outer subroutines will no
4254 longer share a common value for the variable. In other words, the
4255 variable will no longer be shared.
4257 Furthermore, if the outer subroutine is anonymous and references a
4258 lexical variable outside itself, then the outer and inner subroutines
4259 will I<never> share the given variable.
4261 This problem can usually be solved by making the inner subroutine
4262 anonymous, using the C<sub {}> syntax. When inner anonymous subs that
4263 reference variables in outer subroutines are called or referenced, they
4264 are automatically rebound to the current values of such variables.
4266 =item Variable length lookbehind not implemented in regex;
4268 marked by <-- HERE in m/%s/
4270 (F) Lookbehind is allowed only for subexpressions whose length is fixed and
4271 known at compile time. The <-- HERE shows in the regular expression about
4272 where the problem was discovered. See L<perlre>.
4274 =item Version number must be a constant number
4276 (P) The attempt to translate a C<use Module n.n LIST> statement into
4277 its equivalent C<BEGIN> block found an internal inconsistency with
4280 =item v-string in use/require is non-portable
4282 (W portable) The use of v-strings is non-portable to older, pre-5.6, Perls.
4283 If you want your scripts to be backward portable, use the floating
4284 point version number: for example, instead of C<use 5.6.1> say
4285 C<use 5.006_001>. This of course won't help: the older Perls
4286 won't suddenly start understanding newer features, but at least
4287 they will show a sensible error message indicating the required
4290 =item Warning: something's wrong
4292 (W) You passed warn() an empty string (the equivalent of C<warn "">) or
4293 you called it with no args and C<$_> was empty.
4295 =item Warning: unable to close filehandle %s properly
4297 (S) The implicit close() done by an open() got an error indication on
4298 the close(). This usually indicates your file system ran out of disk
4301 =item Warning: Use of "%s" without parentheses is ambiguous
4303 (S ambiguous) You wrote a unary operator followed by something that
4304 looks like a binary operator that could also have been interpreted as a
4305 term or unary operator. For instance, if you know that the rand
4306 function has a default argument of 1.0, and you write
4310 you may THINK you wrote the same thing as
4314 but in actual fact, you got
4318 So put in parentheses to say what you really mean.
4320 =item Wide character in %s
4322 (W utf8) Perl met a wide character (>255) when it wasn't expecting
4323 one. This warning is by default on for I/O (like print) but can be
4324 turned off by C<no warnings 'utf8';>. You are supposed to explicitly
4325 mark the filehandle with an encoding, see L<open> and L<perlfunc/binmode>.
4327 =item write() on closed filehandle %s
4329 (W closed) The filehandle you're writing to got itself closed sometime
4330 before now. Check your control flow.
4332 =item X outside of string
4334 (F) You had a pack template that specified a relative position before
4335 the beginning of the string being unpacked. See L<perlfunc/pack>.
4337 =item x outside of string
4339 (F) You had a pack template that specified a relative position after
4340 the end of the string being unpacked. See L<perlfunc/pack>.
4342 =item Xsub "%s" called in sort
4344 (F) The use of an external subroutine as a sort comparison is not yet
4347 =item Xsub called in sort
4349 (F) The use of an external subroutine as a sort comparison is not yet
4352 =item YOU HAVEN'T DISABLED SET-ID SCRIPTS IN THE KERNEL YET!
4354 (F) And you probably never will, because you probably don't have the
4355 sources to your kernel, and your vendor probably doesn't give a rip
4356 about what you want. Your best bet is to put a setuid C wrapper around
4359 =item You need to quote "%s"
4361 (W syntax) You assigned a bareword as a signal handler name.
4362 Unfortunately, you already have a subroutine of that name declared,
4363 which means that Perl 5 will try to call the subroutine when the
4364 assignment is executed, which is probably not what you want. (If it IS
4365 what you want, put an & in front.)