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 (mandatory).
13 (F) A fatal error (trappable).
14 (P) An internal error you should never see (trappable).
15 (X) A very fatal error (non-trappable).
16 (A) An alien error message (not generated by Perl).
18 Optional warnings are enabled by using the B<-w> switch. Warnings may
19 be captured by setting C<$SIG{__WARN__}> to a reference to a routine that
20 will be called on each warning instead of printing it. See L<perlvar>.
21 Trappable errors may be trapped using the eval operator. See
24 Some of these messages are generic. Spots that vary are denoted with a %s,
25 just as in a printf format. Note that some messages start with a %s!
26 The symbols C<"%-?@> sort before the letters, while C<[> and C<\> sort after.
30 =item "my" variable %s can't be in a package
32 (F) Lexically scoped variables aren't in a package, so it doesn't make sense
33 to try to declare one with a package qualifier on the front. Use local()
34 if you want to localize a package variable.
36 =item "my" variable %s masks earlier declaration in same scope
38 (S) A lexical variable has been redeclared in the same scope, effectively
39 eliminating all access to the previous instance. This is almost always
40 a typographical error. Note that the earlier variable will still exist
41 until the end of the scope or until all closure referents to it are
44 =item "no" not allowed in expression
46 (F) The "no" keyword is recognized and executed at compile time, and returns
47 no useful value. See L<perlmod>.
49 =item "use" not allowed in expression
51 (F) The "use" keyword is recognized and executed at compile time, and returns
52 no useful value. See L<perlmod>.
54 =item % may only be used in unpack
56 (F) You can't pack a string by supplying a checksum, because the
57 checksumming process loses information, and you can't go the other
58 way. See L<perlfunc/unpack>.
60 =item %s (...) interpreted as function
62 (W) You've run afoul of the rule that says that any list operator followed
63 by parentheses turns into a function, with all the list operators arguments
64 found inside the parentheses. See L<perlop/Terms and List Operators (Leftward)>.
66 =item %s argument is not a HASH element
68 (F) The argument to exists() must be a hash element, such as
73 =item %s argument is not a HASH element or slice
75 (F) The argument to delete() must be either a hash element, such as
80 or a hash slice, such as
82 @foo{$bar, $baz, $xyzzy}
83 @{$ref->[12]}{"susie", "queue"}
85 =item %s did not return a true value
87 (F) A required (or used) file must return a true value to indicate that
88 it compiled correctly and ran its initialization code correctly. It's
89 traditional to end such a file with a "1;", though any true value would
90 do. See L<perlfunc/require>.
92 =item %s found where operator expected
94 (S) The Perl lexer knows whether to expect a term or an operator. If it
95 sees what it knows to be a term when it was expecting to see an operator,
96 it gives you this warning. Usually it indicates that an operator or
97 delimiter was omitted, such as a semicolon.
99 =item %s had compilation errors
101 (F) The final summary message when a C<perl -c> fails.
103 =item %s has too many errors
105 (F) The parser has given up trying to parse the program after 10 errors.
106 Further error messages would likely be uninformative.
108 =item %s matches null string many times
110 (W) The pattern you've specified would be an infinite loop if the
111 regular expression engine didn't specifically check for that. See L<perlre>.
113 =item %s never introduced
115 (S) The symbol in question was declared but somehow went out of scope
116 before it could possibly have been used.
120 (F) The final summary message when a C<perl -c> succeeds.
122 =item %s: Command not found
124 (A) You've accidentally run your script through B<csh> instead
125 of Perl. Check the #! line, or manually feed your script into
128 =item %s: Expression syntax
130 (A) You've accidentally run your script through B<csh> instead
131 of Perl. Check the #! line, or manually feed your script into
134 =item %s: Undefined variable
136 (A) You've accidentally run your script through B<csh> instead
137 of Perl. Check the #! line, or manually feed your script into
142 (A) You've accidentally run your script through the Bourne shell
143 instead of Perl. Check the #! line, or manually feed your script
146 =item B<-P> not allowed for setuid/setgid script
148 (F) The script would have to be opened by the C preprocessor by name,
149 which provides a race condition that breaks security.
151 =item C<-T> and C<-B> not implemented on filehandles
153 (F) Perl can't peek at the stdio buffer of filehandles when it doesn't
154 know about your kind of stdio. You'll have to use a filename instead.
156 =item 500 Server error
160 =item ?+* follows nothing in regexp
162 (F) You started a regular expression with a quantifier. Backslash it
163 if you meant it literally. See L<perlre>.
165 =item @ outside of string
167 (F) You had a pack template that specified an absolute position outside
168 the string being unpacked. See L<perlfunc/pack>.
170 =item accept() on closed fd
172 (W) You tried to do an accept on a closed socket. Did you forget to check
173 the return value of your socket() call? See L<perlfunc/accept>.
175 =item Allocation too large: %lx
177 (X) You can't allocate more than 64K on an MSDOS machine.
179 =item Allocation too large
181 (F) You can't allocate more than 2^31+"small amount" bytes.
183 =item Applying %s to %s will act on scalar(%s)
185 (W) The pattern match (//), substitution (s///), and translation (tr///)
186 operators work on scalar values. If you apply one of them to an array
187 or a hash, it will convert the array or hash to a scalar value -- the
188 length of an array, or the population info of a hash -- and then work on
189 that scalar value. This is probably not what you meant to do. See
190 L<perlfunc/grep> and L<perlfunc/map> for alternatives.
192 =item Arg too short for msgsnd
194 (F) msgsnd() requires a string at least as long as sizeof(long).
196 =item Ambiguous use of %s resolved as %s
198 (W)(S) You said something that may not be interpreted the way
199 you thought. Normally it's pretty easy to disambiguate it by supplying
200 a missing quote, operator, parenthesis pair or declaration.
202 =item Args must match #! line
204 (F) The setuid emulator requires that the arguments Perl was invoked
205 with match the arguments specified on the #! line. Since some systems
206 impose a one-argument limit on the #! line, try combining switches;
207 for example, turn C<-w -U> into C<-wU>.
209 =item Argument "%s" isn't numeric%s
211 (W) The indicated string was fed as an argument to an operator that
212 expected a numeric value instead. If you're fortunate the message
213 will identify which operator was so unfortunate.
215 =item Array @%s missing the @ in argument %d of %s()
217 (D) Really old Perl let you omit the @ on array names in some spots. This
218 is now heavily deprecated.
220 =item assertion botched: %s
222 (P) The malloc package that comes with Perl had an internal failure.
224 =item Assertion failed: file "%s"
226 (P) A general assertion failed. The file in question must be examined.
228 =item Assignment to both a list and a scalar
230 (F) If you assign to a conditional operator, the 2nd and 3rd arguments
231 must either both be scalars or both be lists. Otherwise Perl won't
232 know which context to supply to the right side.
234 =item Attempt to free non-arena SV: 0x%lx
236 (P) All SV objects are supposed to be allocated from arenas that will
237 be garbage collected on exit. An SV was discovered to be outside any
240 =item Attempt to free non-existent shared string
242 (P) Perl maintains a reference counted internal table of strings to
243 optimize the storage and access of hash keys and other strings. This
244 indicates someone tried to decrement the reference count of a string
245 that can no longer be found in the table.
247 =item Attempt to free temp prematurely
249 (W) Mortalized values are supposed to be freed by the free_tmps()
250 routine. This indicates that something else is freeing the SV before
251 the free_tmps() routine gets a chance, which means that the free_tmps()
252 routine will be freeing an unreferenced scalar when it does try to free
255 =item Attempt to free unreferenced glob pointers
257 (P) The reference counts got screwed up on symbol aliases.
259 =item Attempt to free unreferenced scalar
261 (W) Perl went to decrement the reference count of a scalar to see if it
262 would go to 0, and discovered that it had already gone to 0 earlier,
263 and should have been freed, and in fact, probably was freed. This
264 could indicate that SvREFCNT_dec() was called too many times, or that
265 SvREFCNT_inc() was called too few times, or that the SV was mortalized
266 when it shouldn't have been, or that memory has been corrupted.
268 =item Attempt to use reference as lvalue in substr
270 (W) You supplied a reference as the first argument to substr() used
271 as an lvalue, which is pretty strange. Perhaps you forgot to
272 dereference it first. See L<perlfunc/substr>.
274 =item Bad arg length for %s, is %d, should be %d
276 (F) You passed a buffer of the wrong size to one of msgctl(), semctl() or
277 shmctl(). In C parlance, the correct sizes are, respectively,
278 S<sizeof(struct msqid_ds *)>, S<sizeof(struct semid_ds *)>, and
279 S<sizeof(struct shmid_ds *)>.
281 =item Bad filehandle: %s
283 (F) A symbol was passed to something wanting a filehandle, but the symbol
284 has no filehandle associated with it. Perhaps you didn't do an open(), or
285 did it in another package.
287 =item Bad free() ignored
289 (S) An internal routine called free() on something that had never been
290 malloc()ed in the first place. Mandatory, but can be disabled by
291 setting environment variable C<PERL_BADFREE> to 1.
293 This message can be quite often seen with DB_File on systems with
294 "hard" dynamic linking, like C<AIX> and C<OS/2>. It is a bug of
295 C<Berkeley DB> which is left unnoticed if C<DB> uses I<forgiving>
300 (P) One of the internal hash routines was passed a null HV pointer.
302 =item Bad name after %s::
304 (F) You started to name a symbol by using a package prefix, and then didn't
305 finish the symbol. In particular, you can't interpolate outside of quotes,
314 $sym = "mypack::$var";
316 =item Bad symbol for array
318 (P) An internal request asked to add an array entry to something that
319 wasn't a symbol table entry.
321 =item Bad symbol for filehandle
323 (P) An internal request asked to add a filehandle entry to something that
324 wasn't a symbol table entry.
326 =item Bad symbol for hash
328 (P) An internal request asked to add a hash entry to something that
329 wasn't a symbol table entry.
331 =item Badly placed ()'s
333 (A) You've accidentally run your script through B<csh> instead
334 of Perl. Check the #! line, or manually feed your script into
337 =item Bareword "%s" not allowed while "strict subs" in use
339 (F) With "strict subs" in use, a bareword is only allowed as a
340 subroutine identifier, in curly braces or to the left of the "=>" symbol.
341 Perhaps you need to pre-declare a subroutine?
343 =item BEGIN failed--compilation aborted
345 (F) An untrapped exception was raised while executing a BEGIN subroutine.
346 Compilation stops immediately and the interpreter is exited.
348 =item BEGIN not safe after errors--compilation aborted
350 (F) Perl found a C<BEGIN {}> subroutine (or a C<use> directive, which
351 implies a C<BEGIN {}>) after one or more compilation errors had
352 already occurred. Since the intended environment for the C<BEGIN {}>
353 could not be guaranteed (due to the errors), and since subsequent code
354 likely depends on its correct operation, Perl just gave up.
356 =item bind() on closed fd
358 (W) You tried to do a bind on a closed socket. Did you forget to check
359 the return value of your socket() call? See L<perlfunc/bind>.
361 =item Bizarre copy of %s in %s
363 (P) Perl detected an attempt to copy an internal value that is not copiable.
365 =item Callback called exit
367 (F) A subroutine invoked from an external package via perl_call_sv()
368 exited by calling exit.
370 =item Can't "goto" outside a block
372 (F) A "goto" statement was executed to jump out of what might look
373 like a block, except that it isn't a proper block. This usually
374 occurs if you tried to jump out of a sort() block or subroutine, which
375 is a no-no. See L<perlfunc/goto>.
377 =item Can't "last" outside a block
379 (F) A "last" statement was executed to break out of the current block,
380 except that there's this itty bitty problem called there isn't a
381 current block. Note that an "if" or "else" block doesn't count as a
382 "loopish" block, as doesn't a block given to sort(). You can usually double
383 the curlies to get the same effect though, because the inner curlies
384 will be considered a block that loops once. See L<perlfunc/last>.
386 =item Can't "next" outside a block
388 (F) A "next" statement was executed to reiterate the current block, but
389 there isn't a current block. Note that an "if" or "else" block doesn't
390 count as a "loopish" block, as doesn't a block given to sort(). You can
391 usually double the curlies to get the same effect though, because the inner
392 curlies will be considered a block that loops once. See L<perlfunc/last>.
394 =item Can't "redo" outside a block
396 (F) A "redo" statement was executed to restart the current block, but
397 there isn't a current block. Note that an "if" or "else" block doesn't
398 count as a "loopish" block, as doesn't a block given to sort(). You can
399 usually double the curlies to get the same effect though, because the inner
400 curlies will be considered a block that loops once. See L<perlfunc/last>.
402 =item Can't bless non-reference value
404 (F) Only hard references may be blessed. This is how Perl "enforces"
405 encapsulation of objects. See L<perlobj>.
407 =item Can't break at that line
409 (S) A warning intended for while running within the debugger, indicating
410 the line number specified wasn't the location of a statement that could
413 =item Can't call method "%s" in empty package "%s"
415 (F) You called a method correctly, and it correctly indicated a package
416 functioning as a class, but that package doesn't have ANYTHING defined
417 in it, let alone methods. See L<perlobj>.
419 =item Can't call method "%s" on unblessed reference
421 (F) A method call must know what package it's supposed to run in. It
422 ordinarily finds this out from the object reference you supply, but
423 you didn't supply an object reference in this case. A reference isn't
424 an object reference until it has been blessed. See L<perlobj>.
426 =item Can't call method "%s" without a package or object reference
428 (F) You used the syntax of a method call, but the slot filled by the
429 object reference or package name contains an expression that returns
430 neither an object reference nor a package name. (Perhaps it's null?)
431 Something like this will reproduce the error:
434 process $BADREF 1,2,3;
435 $BADREF->process(1,2,3);
437 =item Can't chdir to %s
439 (F) You called C<perl -x/foo/bar>, but C</foo/bar> is not a directory
440 that you can chdir to, possibly because it doesn't exist.
442 =item Can't coerce %s to integer in %s
444 (F) Certain types of SVs, in particular real symbol table entries
445 (typeglobs), can't be forced to stop being what they are. So you can't
455 but then $foo no longer contains a glob.
457 =item Can't coerce %s to number in %s
459 (F) Certain types of SVs, in particular real symbol table entries
460 (typeglobs), can't be forced to stop being what they are.
462 =item Can't coerce %s to string in %s
464 (F) Certain types of SVs, in particular real symbol table entries
465 (typeglobs), can't be forced to stop being what they are.
467 =item Can't create pipe mailbox
469 (P) An error peculiar to VMS. The process is suffering from exhausted quotas
470 or other plumbing problems.
472 =item Can't declare %s in my
474 (F) Only scalar, array, and hash variables may be declared as lexical variables.
475 They must have ordinary identifiers as names.
477 =item Can't do inplace edit on %s: %s
479 (S) The creation of the new file failed for the indicated reason.
481 =item Can't do in-place edit without backup
483 (F) You're on a system such as MSDOS that gets confused if you try reading
484 from a deleted (but still opened) file. You have to say B<-i>C<.bak>, or some
487 =item Can't do inplace edit: %s E<gt> 14 characters
489 (S) There isn't enough room in the filename to make a backup name for the file.
491 =item Can't do inplace edit: %s is not a regular file
493 (S) You tried to use the B<-i> switch on a special file, such as a file in
494 /dev, or a FIFO. The file was ignored.
496 =item Can't do setegid!
498 (P) The setegid() call failed for some reason in the setuid emulator
501 =item Can't do seteuid!
503 (P) The setuid emulator of suidperl failed for some reason.
505 =item Can't do setuid
507 (F) This typically means that ordinary perl tried to exec suidperl to
508 do setuid emulation, but couldn't exec it. It looks for a name of the
509 form sperl5.000 in the same directory that the perl executable resides
510 under the name perl5.000, typically /usr/local/bin on Unix machines.
511 If the file is there, check the execute permissions. If it isn't, ask
512 your sysadmin why he and/or she removed it.
514 =item Can't do waitpid with flags
516 (F) This machine doesn't have either waitpid() or wait4(), so only waitpid()
517 without flags is emulated.
519 =item Can't do {n,m} with n E<gt> m
521 (F) Minima must be less than or equal to maxima. If you really want
522 your regexp to match something 0 times, just put {0}. See L<perlre>.
524 =item Can't emulate -%s on #! line
526 (F) The #! line specifies a switch that doesn't make sense at this point.
527 For example, it'd be kind of silly to put a B<-x> on the #! line.
529 =item Can't exec "%s": %s
531 (W) An system(), exec(), or piped open call could not execute the named
532 program for the indicated reason. Typical reasons include: the permissions
533 were wrong on the file, the file wasn't found in C<$ENV{PATH}>, the
534 executable in question was compiled for another architecture, or the
535 #! line in a script points to an interpreter that can't be run for
536 similar reasons. (Or maybe your system doesn't support #! at all.)
540 (F) Perl was trying to execute the indicated program for you because that's
541 what the #! line said. If that's not what you wanted, you may need to
542 mention "perl" on the #! line somewhere.
544 =item Can't execute %s
546 (F) You used the B<-S> switch, but the script to execute could not be found
547 in the PATH, or at least not with the correct permissions.
549 =item Can't find label %s
551 (F) You said to goto a label that isn't mentioned anywhere that it's possible
552 for us to go to. See L<perlfunc/goto>.
554 =item Can't find string terminator %s anywhere before EOF
556 (F) Perl strings can stretch over multiple lines. This message means that
557 the closing delimiter was omitted. Because bracketed quotes count nesting
558 levels, the following is missing its final parenthesis:
560 print q(The character '(' starts a side comment.)
564 (F) A fatal error occurred while trying to fork while opening a pipeline.
566 =item Unsupported function fork
568 (F) Your version of executable does not support forking.
570 Note that under some systems, like OS/2, there may be different flavors of
571 Perl executables, some of which may support fork, some not. Try changing
572 the name you call Perl by to C<perl_>, C<perl__>, and so on.
574 =item Can't get filespec - stale stat buffer?
576 (S) A warning peculiar to VMS. This arises because of the difference between
577 access checks under VMS and under the Unix model Perl assumes. Under VMS,
578 access checks are done by filename, rather than by bits in the stat buffer, so
579 that ACLs and other protections can be taken into account. Unfortunately, Perl
580 assumes that the stat buffer contains all the necessary information, and passes
581 it, instead of the filespec, to the access checking routine. It will try to
582 retrieve the filespec using the device name and FID present in the stat buffer,
583 but this works only if you haven't made a subsequent call to the CRTL stat()
584 routine, because the device name is overwritten with each call. If this warning
585 appears, the name lookup failed, and the access checking routine gave up and
586 returned FALSE, just to be conservative. (Note: The access checking routine
587 knows about the Perl C<stat> operator and file tests, so you shouldn't ever
588 see this warning in response to a Perl command; it arises only if some internal
589 code takes stat buffers lightly.)
591 =item Can't get pipe mailbox device name
593 (P) An error peculiar to VMS. After creating a mailbox to act as a pipe, Perl
594 can't retrieve its name for later use.
596 =item Can't get SYSGEN parameter value for MAXBUF
598 (P) An error peculiar to VMS. Perl asked $GETSYI how big you want your
599 mailbox buffers to be, and didn't get an answer.
601 =item Can't goto subroutine outside a subroutine
603 (F) The deeply magical "goto subroutine" call can only replace one subroutine
604 call for another. It can't manufacture one out of whole cloth. In general
605 you should be calling it out of only an AUTOLOAD routine anyway. See
608 =item Can't localize a reference
610 (F) You said something like C<local $$ref>, which is not allowed because
611 the compiler can't determine whether $ref will end up pointing to anything
612 with a symbol table entry, and a symbol table entry is necessary to
615 =item Can't localize lexical variable %s
617 (F) You used local on a variable name that was previously declared as a
618 lexical variable using "my". This is not allowed. If you want to
619 localize a package variable of the same name, qualify it with the
622 =item Can't locate %s in @INC
624 (F) You said to do (or require, or use) a file that couldn't be found
625 in any of the libraries mentioned in @INC. Perhaps you need to set
626 the PERL5LIB environment variable to say where the extra library is,
627 or maybe the script needs to add the library name to @INC. Or maybe
628 you just misspelled the name of the file. See L<perlfunc/require>.
630 =item Can't locate object method "%s" via package "%s"
632 (F) You called a method correctly, and it correctly indicated a package
633 functioning as a class, but that package doesn't define that particular
634 method, nor does any of its base classes. See L<perlobj>.
636 =item Can't locate package %s for @%s::ISA
638 (W) The @ISA array contained the name of another package that doesn't seem
643 (F) The mktemp() routine failed for some reason while trying to process
644 a B<-e> switch. Maybe your /tmp partition is full, or clobbered.
646 =item Can't modify %s in %s
648 (F) You aren't allowed to assign to the item indicated, or otherwise try to
649 change it, such as with an auto-increment.
651 =item Can't modify non-existent substring
653 (P) The internal routine that does assignment to a substr() was handed
656 =item Can't msgrcv to read-only var
658 (F) The target of a msgrcv must be modifiable to be used as a receive
661 =item Can't open %s: %s
663 (S) An in-place edit couldn't open the original file for the indicated reason.
664 Usually this is because you don't have read permission for the file.
666 =item Can't open bidirectional pipe
668 (W) You tried to say C<open(CMD, "|cmd|")>, which is not supported. You can
669 try any of several modules in the Perl library to do this, such as
670 IPC::Open2. Alternately, direct the pipe's output to a file using "E<gt>",
671 and then read it in under a different file handle.
673 =item Can't open error file %s as stderr
675 (F) An error peculiar to VMS. Perl does its own command line redirection, and
676 couldn't open the file specified after '2E<gt>' or '2E<gt>E<gt>' on the
677 command line for writing.
679 =item Can't open input file %s as stdin
681 (F) An error peculiar to VMS. Perl does its own command line redirection, and
682 couldn't open the file specified after 'E<lt>' on the command line for reading.
684 =item Can't open output file %s as stdout
686 (F) An error peculiar to VMS. Perl does its own command line redirection, and
687 couldn't open the file specified after 'E<gt>' or 'E<gt>E<gt>' on the command
690 =item Can't open output pipe (name: %s)
692 (P) An error peculiar to VMS. Perl does its own command line redirection, and
693 couldn't open the pipe into which to send data destined for stdout.
695 =item Can't open perl script "%s": %s
697 (F) The script you specified can't be opened for the indicated reason.
699 =item Can't rename %s to %s: %s, skipping file
701 (S) The rename done by the B<-i> switch failed for some reason, probably because
702 you don't have write permission to the directory.
704 =item Can't reopen input pipe (name: %s) in binary mode
706 (P) An error peculiar to VMS. Perl thought stdin was a pipe, and tried to
707 reopen it to accept binary data. Alas, it failed.
709 =item Can't reswap uid and euid
711 (P) The setreuid() call failed for some reason in the setuid emulator
714 =item Can't return outside a subroutine
716 (F) The return statement was executed in mainline code, that is, where
717 there was no subroutine call to return out of. See L<perlsub>.
719 =item Can't stat script "%s"
721 (P) For some reason you can't fstat() the script even though you have
722 it open already. Bizarre.
724 =item Can't swap uid and euid
726 (P) The setreuid() call failed for some reason in the setuid emulator
729 =item Can't take log of %g
731 (F) Logarithms are defined on only positive real numbers.
733 =item Can't take sqrt of %g
735 (F) For ordinary real numbers, you can't take the square root of a
736 negative number. There's a Complex package available for Perl, though,
737 if you really want to do that.
739 =item Can't undef active subroutine
741 (F) You can't undefine a routine that's currently running. You can,
742 however, redefine it while it's running, and you can even undef the
743 redefined subroutine while the old routine is running. Go figure.
747 (F) You tried to unshift an "unreal" array that can't be unshifted, such
748 as the main Perl stack.
750 =item Can't upgrade that kind of scalar
752 (P) The internal sv_upgrade routine adds "members" to an SV, making
753 it into a more specialized kind of SV. The top several SV types are
754 so specialized, however, that they cannot be interconverted. This
755 message indicates that such a conversion was attempted.
757 =item Can't upgrade to undef
759 (P) The undefined SV is the bottom of the totem pole, in the scheme
760 of upgradability. Upgrading to undef indicates an error in the
761 code calling sv_upgrade.
763 =item Can't use "my %s" in sort comparison
765 (F) The global variables $a and $b are reserved for sort comparisons.
766 You mentioned $a or $b in the same line as the E<lt>=E<gt> or cmp operator,
767 and the variable had earlier been declared as a lexical variable.
768 Either qualify the sort variable with the package name, or rename the
771 =item Can't use %s for loop variable
773 (F) Only a simple scalar variable may be used as a loop variable on a foreach.
775 =item Can't use %s ref as %s ref
777 (F) You've mixed up your reference types. You have to dereference a
778 reference of the type needed. You can use the ref() function to
779 test the type of the reference, if need be.
781 =item Can't use \1 to mean $1 in expression
783 (W) In an ordinary expression, backslash is a unary operator that creates
784 a reference to its argument. The use of backslash to indicate a backreference
785 to a matched substring is valid only as part of a regular expression pattern.
786 Trying to do this in ordinary Perl code produces a value that prints
787 out looking like SCALAR(0xdecaf). Use the $1 form instead.
789 =item Can't use bareword ("%s") as %s ref while \"strict refs\" in use
791 (F) Only hard references are allowed by "strict refs". Symbolic references
792 are disallowed. See L<perlref>.
794 =item Can't use string ("%s") as %s ref while "strict refs" in use
796 (F) Only hard references are allowed by "strict refs". Symbolic references
797 are disallowed. See L<perlref>.
799 =item Can't use an undefined value as %s reference
801 (F) A value used as either a hard reference or a symbolic reference must
802 be a defined value. This helps to de-lurk some insidious errors.
804 =item Can't use global %s in "my"
806 (F) You tried to declare a magical variable as a lexical variable. This is
807 not allowed, because the magic can be tied to only one location (namely
808 the global variable) and it would be incredibly confusing to have
809 variables in your program that looked like magical variables but
812 =item Can't use subscript on %s
814 (F) The compiler tried to interpret a bracketed expression as a
815 subscript. But to the left of the brackets was an expression that
816 didn't look like an array reference, or anything else subscriptable.
818 =item Can't write to temp file for B<-e>: %s
820 (F) The write routine failed for some reason while trying to process
821 a B<-e> switch. Maybe your /tmp partition is full, or clobbered.
823 =item Can't x= to read-only value
825 (F) You tried to repeat a constant value (often the undefined value) with
826 an assignment operator, which implies modifying the value itself.
827 Perhaps you need to copy the value to a temporary, and repeat that.
829 =item Cannot open temporary file
831 (F) The create routine failed for some reason while trying to process
832 a B<-e> switch. Maybe your /tmp partition is full, or clobbered.
834 =item Cannot resolve method `%s' overloading `%s' in package `%s'
836 (F|P) Error resolving overloading specified by a method name (as
837 opposed to a subroutine reference): no such method callable via the
838 package. If method name is C<???>, this is an internal error.
840 =item chmod: mode argument is missing initial 0
842 (W) A novice will sometimes say
846 not realizing that 777 will be interpreted as a decimal number, equivalent
847 to 01411. Octal constants are introduced with a leading 0 in Perl, as in C.
849 =item Close on unopened file E<lt>%sE<gt>
851 (W) You tried to close a filehandle that was never opened.
853 =item connect() on closed fd
855 (W) You tried to do a connect on a closed socket. Did you forget to check
856 the return value of your socket() call? See L<perlfunc/connect>.
858 =item Constant subroutine %s redefined
860 (S) You redefined a subroutine which had previously been eligible for
861 inlining. See L<perlsub/"Constant Functions"> for commentary and
864 =item Constant subroutine %s undefined
866 (S) You undefined a subroutine which had previously been eligible for
867 inlining. See L<perlsub/"Constant Functions"> for commentary and
870 =item Copy method did not return a reference
872 (F) The method which overloads "=" is buggy. See L<overload/Copy Constructor>.
874 =item Corrupt malloc ptr 0x%lx at 0x%lx
876 (P) The malloc package that comes with Perl had an internal failure.
878 =item corrupted regexp pointers
880 (P) The regular expression engine got confused by what the regular
881 expression compiler gave it.
883 =item corrupted regexp program
885 (P) The regular expression engine got passed a regexp program without
886 a valid magic number.
888 =item Deep recursion on subroutine "%s"
890 (W) This subroutine has called itself (directly or indirectly) 100
891 times than it has returned. This probably indicates an infinite
892 recursion, unless you're writing strange benchmark programs, in which
893 case it indicates something else.
895 =item Did you mean &%s instead?
897 (W) You probably referred to an imported subroutine &FOO as $FOO or some such.
899 =item Did you mean $ or @ instead of %?
901 (W) You probably said %hash{$key} when you meant $hash{$key} or @hash{@keys}.
902 On the other hand, maybe you just meant %hash and got carried away.
906 (F) You passed die() an empty string (the equivalent of C<die "">) or
907 you called it with no args and both C<$@> and C<$_> were empty.
909 =item Do you need to pre-declare %s?
911 (S) This is an educated guess made in conjunction with the message "%s
912 found where operator expected". It often means a subroutine or module
913 name is being referenced that hasn't been declared yet. This may be
914 because of ordering problems in your file, or because of a missing
915 "sub", "package", "require", or "use" statement. If you're
916 referencing something that isn't defined yet, you don't actually have
917 to define the subroutine or package before the current location. You
918 can use an empty "sub foo;" or "package FOO;" to enter a "forward"
921 =item Don't know how to handle magic of type '%s'
923 (P) The internal handling of magical variables has been cursed.
925 =item do_study: out of memory
927 (P) This should have been caught by safemalloc() instead.
929 =item Duplicate free() ignored
931 (S) An internal routine called free() on something that had already
934 =item elseif should be elsif
936 (S) There is no keyword "elseif" in Perl because Larry thinks it's
937 ugly. Your code will be interpreted as an attempt to call a method
938 named "elseif" for the class returned by the following block. This is
939 unlikely to be what you want.
941 =item END failed--cleanup aborted
943 (F) An untrapped exception was raised while executing an END subroutine.
944 The interpreter is immediately exited.
946 =item Error converting file specification %s
948 (F) An error peculiar to VMS. Because Perl may have to deal with file
949 specifications in either VMS or Unix syntax, it converts them to a
950 single form when it must operate on them directly. Either you've
951 passed an invalid file specification to Perl, or you've found a
952 case the conversion routines don't handle. Drat.
954 =item Execution of %s aborted due to compilation errors
956 (F) The final summary message when a Perl compilation fails.
958 =item Exiting eval via %s
960 (W) You are exiting an eval by unconventional means, such as
961 a goto, or a loop control statement.
963 =item Exiting pseudo-block via %s
965 (W) You are exiting a rather special block construct (like a sort block or
966 subroutine) by unconventional means, such as a goto, or a loop control
967 statement. See L<perlfunc/sort>.
969 =item Exiting subroutine via %s
971 (W) You are exiting a subroutine by unconventional means, such as
972 a goto, or a loop control statement.
974 =item Exiting substitution via %s
976 (W) You are exiting a substitution by unconventional means, such as
977 a return, a goto, or a loop control statement.
979 =item Fatal VMS error at %s, line %d
981 (P) An error peculiar to VMS. Something untoward happened in a VMS system
982 service or RTL routine; Perl's exit status should provide more details. The
983 filename in "at %s" and the line number in "line %d" tell you which section of
984 the Perl source code is distressed.
986 =item fcntl is not implemented
988 (F) Your machine apparently doesn't implement fcntl(). What is this, a
991 =item Filehandle %s never opened
993 (W) An I/O operation was attempted on a filehandle that was never initialized.
994 You need to do an open() or a socket() call, or call a constructor from
995 the FileHandle package.
997 =item Filehandle %s opened for only input
999 (W) You tried to write on a read-only filehandle. If you
1000 intended it to be a read-write filehandle, you needed to open it with
1001 "+E<lt>" or "+E<gt>" or "+E<gt>E<gt>" instead of with "E<lt>" or nothing. If
1002 you intended only to write the file, use "E<gt>" or "E<gt>E<gt>". See
1005 =item Filehandle opened for only input
1007 (W) You tried to write on a read-only filehandle. If you
1008 intended it to be a read-write filehandle, you needed to open it with
1009 "+E<lt>" or "+E<gt>" or "+E<gt>E<gt>" instead of with "E<lt>" or nothing. If
1010 you intended only to write the file, use "E<gt>" or "E<gt>E<gt>". See
1013 =item Final $ should be \$ or $name
1015 (F) You must now decide whether the final $ in a string was meant to be
1016 a literal dollar sign, or was meant to introduce a variable name
1017 that happens to be missing. So you have to put either the backslash or
1020 =item Final @ should be \@ or @name
1022 (F) You must now decide whether the final @ in a string was meant to be
1023 a literal "at" sign, or was meant to introduce a variable name
1024 that happens to be missing. So you have to put either the backslash or
1027 =item Format %s redefined
1029 (W) You redefined a format. To suppress this warning, say
1033 eval "format NAME =...";
1036 =item Format not terminated
1038 (F) A format must be terminated by a line with a solitary dot. Perl got
1039 to the end of your file without finding such a line.
1041 =item Found = in conditional, should be ==
1051 (or something like that).
1053 =item gdbm store returned %d, errno %d, key "%s"
1055 (S) A warning from the GDBM_File extension that a store failed.
1057 =item gethostent not implemented
1059 (F) Your C library apparently doesn't implement gethostent(), probably
1060 because if it did, it'd feel morally obligated to return every hostname
1063 =item get{sock,peer}name() on closed fd
1065 (W) You tried to get a socket or peer socket name on a closed socket.
1066 Did you forget to check the return value of your socket() call?
1068 =item getpwnam returned invalid UIC %#o for user "%s"
1070 (S) A warning peculiar to VMS. The call to C<sys$getuai> underlying the
1071 C<getpwnam> operator returned an invalid UIC.
1074 =item Glob not terminated
1076 (F) The lexer saw a left angle bracket in a place where it was expecting
1077 a term, so it's looking for the corresponding right angle bracket, and not
1078 finding it. Chances are you left some needed parentheses out earlier in
1079 the line, and you really meant a "less than".
1081 =item Global symbol "%s" requires explicit package name
1083 (F) You've said "use strict vars", which indicates that all variables
1084 must either be lexically scoped (using "my"), or explicitly qualified to
1085 say which package the global variable is in (using "::").
1087 =item goto must have label
1089 (F) Unlike with "next" or "last", you're not allowed to goto an
1090 unspecified destination. See L<perlfunc/goto>.
1092 =item Had to create %s unexpectedly
1094 (S) A routine asked for a symbol from a symbol table that ought to have
1095 existed already, but for some reason it didn't, and had to be created on
1096 an emergency basis to prevent a core dump.
1098 =item Hash %%s missing the % in argument %d of %s()
1100 (D) Really old Perl let you omit the % on hash names in some spots. This
1101 is now heavily deprecated.
1103 =item Ill-formed logical name |%s| in prime_env_iter
1105 (W) A warning peculiar to VMS. A logical name was encountered when preparing
1106 to iterate over %ENV which violates the syntactic rules governing logical
1107 names. Because it cannot be translated normally, it is skipped, and will not
1108 appear in %ENV. This may be a benign occurrence, as some software packages
1109 might directly modify logical name tables and introduce non-standard names,
1110 or it may indicate that a logical name table has been corrupted.
1112 =item Illegal character %s (carriage return)
1114 (F) A carriage return character was found in the input. This is an
1115 error, and not a warning, because carriage return characters can break
1116 here documents (e.g., C<print E<lt>E<lt>EOF;>).
1118 Under UNIX, this error is usually caused by executing Perl code --
1119 either the main program, a module, or an eval'd string -- that was
1120 transferred over a network connection from a non-UNIX system without
1121 properly converting the text file format.
1123 Under systems that use something other than '\n' to delimit lines of
1124 text, this error can also be caused by reading Perl code from a file
1125 handle that is in binary mode (as set by the C<binmode> operator).
1127 In either case, the Perl code in question will probably need to be
1128 converted with something like C<s/\x0D\x0A?/\n/g> before it can be
1131 =item Illegal division by zero
1133 (F) You tried to divide a number by 0. Either something was wrong in your
1134 logic, or you need to put a conditional in to guard against meaningless input.
1136 =item Illegal modulus zero
1138 (F) You tried to divide a number by 0 to get the remainder. Most numbers
1139 don't take to this kindly.
1141 =item Illegal octal digit
1143 (F) You used an 8 or 9 in a octal number.
1145 =item Illegal octal digit ignored
1147 (W) You may have tried to use an 8 or 9 in a octal number. Interpretation
1148 of the octal number stopped before the 8 or 9.
1150 =item In string, @%s now must be written as \@%s
1152 (F) It used to be that Perl would try to guess whether you wanted an
1153 array interpolated or a literal @. It did this when the string was first
1154 used at runtime. Now strings are parsed at compile time, and ambiguous
1155 instances of @ must be disambiguated, either by prepending a backslash to
1156 indicate a literal, or by declaring (or using) the array within the
1157 program before the string (lexically). (Someday it will simply assume
1158 that an unbackslashed @ interpolates an array.)
1160 =item Insecure dependency in %s
1162 (F) You tried to do something that the tainting mechanism didn't like.
1163 The tainting mechanism is turned on when you're running setuid or setgid,
1164 or when you specify B<-T> to turn it on explicitly. The tainting mechanism
1165 labels all data that's derived directly or indirectly from the user,
1166 who is considered to be unworthy of your trust. If any such data is
1167 used in a "dangerous" operation, you get this error. See L<perlsec>
1168 for more information.
1170 =item Insecure directory in %s
1172 (F) You can't use system(), exec(), or a piped open in a setuid or setgid
1173 script if C<$ENV{PATH}> contains a directory that is writable by the world.
1178 (F) You can't use system(), exec(), or a piped open in a setuid or
1179 setgid script if C<$ENV{PATH}> is derived from data supplied (or
1180 potentially supplied) by the user. The script must set the path to a
1181 known value, using trustworthy data. See L<perlsec>.
1183 =item Integer overflow in hex number
1185 (S) The literal hex number you have specified is too big for your
1186 architecture. On a 32-bit architecture the largest hex literal is
1189 =item Integer overflow in octal number
1191 (S) The literal octal number you have specified is too big for your
1192 architecture. On a 32-bit architecture the largest octal literal is
1195 =item Internal inconsistency in tracking vforks
1197 (S) A warning peculiar to VMS. Perl keeps track of the number
1198 of times you've called C<fork> and C<exec>, to determine
1199 whether the current call to C<exec> should affect the current
1200 script or a subprocess (see L<perlvms/exec>). Somehow, this count
1201 has become scrambled, so Perl is making a guess and treating
1202 this C<exec> as a request to terminate the Perl script
1203 and execute the specified command.
1205 =item internal disaster in regexp
1207 (P) Something went badly wrong in the regular expression parser.
1209 =item internal urp in regexp at /%s/
1211 (P) Something went badly awry in the regular expression parser.
1213 =item invalid [] range in regexp
1215 (F) The range specified in a character class had a minimum character
1216 greater than the maximum character. See L<perlre>.
1218 =item ioctl is not implemented
1220 (F) Your machine apparently doesn't implement ioctl(), which is pretty
1221 strange for a machine that supports C.
1223 =item junk on end of regexp
1225 (P) The regular expression parser is confused.
1227 =item Label not found for "last %s"
1229 (F) You named a loop to break out of, but you're not currently in a
1230 loop of that name, not even if you count where you were called from.
1231 See L<perlfunc/last>.
1233 =item Label not found for "next %s"
1235 (F) You named a loop to continue, but you're not currently in a loop of
1236 that name, not even if you count where you were called from. See
1239 =item Label not found for "redo %s"
1241 (F) You named a loop to restart, but you're not currently in a loop of
1242 that name, not even if you count where you were called from. See
1245 =item listen() on closed fd
1247 (W) You tried to do a listen on a closed socket. Did you forget to check
1248 the return value of your socket() call? See L<perlfunc/listen>.
1250 =item Method for operation %s not found in package %s during blessing
1252 (F) An attempt was made to specify an entry in an overloading table that
1253 doesn't resolve to a valid subroutine. See L<overload>.
1255 =item Might be a runaway multi-line %s string starting on line %d
1257 (S) An advisory indicating that the previous error may have been caused
1258 by a missing delimiter on a string or pattern, because it eventually
1259 ended earlier on the current line.
1261 =item Misplaced _ in number
1263 (W) An underline in a decimal constant wasn't on a 3-digit boundary.
1265 =item Missing $ on loop variable
1267 (F) Apparently you've been programming in B<csh> too much. Variables are always
1268 mentioned with the $ in Perl, unlike in the shells, where it can vary from
1269 one line to the next.
1271 =item Missing comma after first argument to %s function
1273 (F) While certain functions allow you to specify a filehandle or an
1274 "indirect object" before the argument list, this ain't one of them.
1276 =item Missing operator before %s?
1278 (S) This is an educated guess made in conjunction with the message "%s
1279 found where operator expected". Often the missing operator is a comma.
1281 =item Missing right bracket
1283 (F) The lexer counted more opening curly brackets (braces) than closing ones.
1284 As a general rule, you'll find it's missing near the place you were last
1287 =item Missing semicolon on previous line?
1289 (S) This is an educated guess made in conjunction with the message "%s
1290 found where operator expected". Don't automatically put a semicolon on
1291 the previous line just because you saw this message.
1293 =item Modification of a read-only value attempted
1295 (F) You tried, directly or indirectly, to change the value of a
1296 constant. You didn't, of course, try "2 = 1", because the compiler
1297 catches that. But an easy way to do the same thing is:
1299 sub mod { $_[0] = 1 }
1302 Another way is to assign to a substr() that's off the end of the string.
1304 =item Modification of non-creatable array value attempted, subscript %d
1306 (F) You tried to make an array value spring into existence, and the
1307 subscript was probably negative, even counting from end of the array
1310 =item Modification of non-creatable hash value attempted, subscript "%s"
1312 (F) You tried to make a hash value spring into existence, and it couldn't
1313 be created for some peculiar reason.
1315 =item Module name must be constant
1317 (F) Only a bare module name is allowed as the first argument to a "use".
1319 =item msg%s not implemented
1321 (F) You don't have System V message IPC on your system.
1323 =item Multidimensional syntax %s not supported
1325 (W) Multidimensional arrays aren't written like C<$foo[1,2,3]>. They're written
1326 like C<$foo[1][2][3]>, as in C.
1328 =item Name "%s::%s" used only once: possible typo
1330 (W) Typographical errors often show up as unique variable names.
1331 If you had a good reason for having a unique name, then just mention
1332 it again somehow to suppress the message. The C<use vars> pragma is
1333 provided for just this purpose.
1335 =item Negative length
1337 (F) You tried to do a read/write/send/recv operation with a buffer length
1338 that is less than 0. This is difficult to imagine.
1340 =item nested *?+ in regexp
1342 (F) You can't quantify a quantifier without intervening parentheses. So
1343 things like ** or +* or ?* are illegal.
1345 Note, however, that the minimal matching quantifiers, C<*?>, C<+?>, and C<??> appear
1346 to be nested quantifiers, but aren't. See L<perlre>.
1350 (F) The setuid emulator requires that scripts have a well-formed #! line
1351 even on machines that don't support the #! construct.
1353 =item No %s allowed while running setuid
1355 (F) Certain operations are deemed to be too insecure for a setuid or setgid
1356 script to even be allowed to attempt. Generally speaking there will be
1357 another way to do what you want that is, if not secure, at least securable.
1360 =item No B<-e> allowed in setuid scripts
1362 (F) A setuid script can't be specified by the user.
1364 =item No comma allowed after %s
1366 (F) A list operator that has a filehandle or "indirect object" is not
1367 allowed to have a comma between that and the following arguments.
1368 Otherwise it'd be just another one of the arguments.
1370 One possible cause for this is that you expected to have imported a
1371 constant to your name space with B<use> or B<import> while no such
1372 importing took place, it may for example be that your operating system
1373 does not support that particular constant. Hopefully you did use an
1374 explicit import list for the constants you expect to see, please see
1375 L<perlfunc/use> and L<perlfunc/import>. While an explicit import list
1376 would probably have caught this error earlier it naturally does not
1377 remedy the fact that your operating system still does not support that
1378 constant. Maybe you have a typo in the constants of the symbol import
1379 list of B<use> or B<import> or in the constant name at the line where
1380 this error was triggered?
1382 =item No command into which to pipe on command line
1384 (F) An error peculiar to VMS. Perl handles its own command line redirection,
1385 and found a '|' at the end of the command line, so it doesn't know whither you
1386 want to pipe the output from this command.
1388 =item No DB::DB routine defined
1390 (F) The currently executing code was compiled with the B<-d> switch,
1391 but for some reason the perl5db.pl file (or some facsimile thereof)
1392 didn't define a routine to be called at the beginning of each
1393 statement. Which is odd, because the file should have been required
1394 automatically, and should have blown up the require if it didn't parse
1397 =item No dbm on this machine
1399 (P) This is counted as an internal error, because every machine should
1400 supply dbm nowadays, because Perl comes with SDBM. See L<SDBM_File>.
1402 =item No DBsub routine
1404 (F) The currently executing code was compiled with the B<-d> switch,
1405 but for some reason the perl5db.pl file (or some facsimile thereof)
1406 didn't define a DB::sub routine to be called at the beginning of each
1407 ordinary subroutine call.
1409 =item No error file after 2E<gt> or 2E<gt>E<gt> on command line
1411 (F) An error peculiar to VMS. Perl handles its own command line redirection,
1412 and found a '2E<gt>' or a '2E<gt>E<gt>' on the command line, but can't find
1413 the name of the file to which to write data destined for stderr.
1415 =item No input file after E<lt> on command line
1417 (F) An error peculiar to VMS. Perl handles its own command line redirection,
1418 and found a 'E<lt>' on the command line, but can't find the name of the file
1419 from which to read data for stdin.
1421 =item No output file after E<gt> on command line
1423 (F) An error peculiar to VMS. Perl handles its own command line redirection,
1424 and found a lone 'E<gt>' at the end of the command line, so it doesn't know
1425 whither you wanted to redirect stdout.
1427 =item No output file after E<gt> or E<gt>E<gt> on command line
1429 (F) An error peculiar to VMS. Perl handles its own command line redirection,
1430 and found a 'E<gt>' or a 'E<gt>E<gt>' on the command line, but can't find the
1431 name of the file to which to write data destined for stdout.
1433 =item No Perl script found in input
1435 (F) You called C<perl -x>, but no line was found in the file beginning
1436 with #! and containing the word "perl".
1438 =item No setregid available
1440 (F) Configure didn't find anything resembling the setregid() call for
1443 =item No setreuid available
1445 (F) Configure didn't find anything resembling the setreuid() call for
1448 =item No space allowed after B<-I>
1450 (F) The argument to B<-I> must follow the B<-I> immediately with no
1453 =item No such pipe open
1455 (P) An error peculiar to VMS. The internal routine my_pclose() tried to
1456 close a pipe which hadn't been opened. This should have been caught earlier as
1457 an attempt to close an unopened filehandle.
1459 =item No such signal: SIG%s
1461 (W) You specified a signal name as a subscript to %SIG that was not recognized.
1462 Say C<kill -l> in your shell to see the valid signal names on your system.
1464 =item Not a CODE reference
1466 (F) Perl was trying to evaluate a reference to a code value (that is, a
1467 subroutine), but found a reference to something else instead. You can
1468 use the ref() function to find out what kind of ref it really was.
1469 See also L<perlref>.
1471 =item Not a format reference
1473 (F) I'm not sure how you managed to generate a reference to an anonymous
1474 format, but this indicates you did, and that it didn't exist.
1476 =item Not a GLOB reference
1478 (F) Perl was trying to evaluate a reference to a "typeglob" (that is,
1479 a symbol table entry that looks like C<*foo>), but found a reference to
1480 something else instead. You can use the ref() function to find out
1481 what kind of ref it really was. See L<perlref>.
1483 =item Not a HASH reference
1485 (F) Perl was trying to evaluate a reference to a hash value, but
1486 found a reference to something else instead. You can use the ref()
1487 function to find out what kind of ref it really was. See L<perlref>.
1489 =item Not a perl script
1491 (F) The setuid emulator requires that scripts have a well-formed #! line
1492 even on machines that don't support the #! construct. The line must
1495 =item Not a SCALAR reference
1497 (F) Perl was trying to evaluate a reference to a scalar value, but
1498 found a reference to something else instead. You can use the ref()
1499 function to find out what kind of ref it really was. See L<perlref>.
1501 =item Not a subroutine reference
1503 (F) Perl was trying to evaluate a reference to a code value (that is, a
1504 subroutine), but found a reference to something else instead. You can
1505 use the ref() function to find out what kind of ref it really was.
1506 See also L<perlref>.
1508 =item Not a subroutine reference in overload table
1510 (F) An attempt was made to specify an entry in an overloading table that
1511 doesn't somehow point to a valid subroutine. See L<overload>.
1513 =item Not an ARRAY reference
1515 (F) Perl was trying to evaluate a reference to an array value, but
1516 found a reference to something else instead. You can use the ref()
1517 function to find out what kind of ref it really was. See L<perlref>.
1519 =item Not enough arguments for %s
1521 (F) The function requires more arguments than you specified.
1523 =item Not enough format arguments
1525 (W) A format specified more picture fields than the next line supplied.
1528 =item Null filename used
1530 (F) You can't require the null filename, especially because on many machines
1531 that means the current directory! See L<perlfunc/require>.
1533 =item Null picture in formline
1535 (F) The first argument to formline must be a valid format picture
1536 specification. It was found to be empty, which probably means you
1537 supplied it an uninitialized value. See L<perlform>.
1539 =item NULL OP IN RUN
1541 (P) Some internal routine called run() with a null opcode pointer.
1545 (P) An attempt was made to realloc NULL.
1547 =item NULL regexp argument
1549 (P) The internal pattern matching routines blew it big time.
1551 =item NULL regexp parameter
1553 (P) The internal pattern matching routines are out of their gourd.
1555 =item Odd number of elements in hash list
1557 (S) You specified an odd number of elements to a hash list, which is odd,
1558 because hash lists come in key/value pairs.
1560 =item Offset outside string
1562 (F) You tried to do a read/write/send/recv operation with an offset
1563 pointing outside the buffer. This is difficult to imagine.
1564 The sole exception to this is that C<sysread()>ing past the buffer
1565 will extend the buffer and zero pad the new area.
1569 (S) An internal warning that the grammar is screwed up.
1573 (S) An internal warning that the grammar is screwed up.
1575 =item Operation `%s': no method found,%s
1577 (F) An attempt was made to perform an overloaded operation for which
1578 no handler was defined. While some handlers can be autogenerated in
1579 terms of other handlers, there is no default handler for any
1580 operation, unless C<fallback> overloading key is specified to be
1581 true. See L<overload>.
1583 =item Operator or semicolon missing before %s
1585 (S) You used a variable or subroutine call where the parser was
1586 expecting an operator. The parser has assumed you really meant
1587 to use an operator, but this is highly likely to be incorrect.
1588 For example, if you say "*foo *foo" it will be interpreted as
1589 if you said "*foo * 'foo'".
1591 =item Out of memory for yacc stack
1593 (F) The yacc parser wanted to grow its stack so it could continue parsing,
1594 but realloc() wouldn't give it more memory, virtual or otherwise.
1596 =item Out of memory!
1598 (X|F) The malloc() function returned 0, indicating there was insufficient
1599 remaining memory (or virtual memory) to satisfy the request.
1601 The request was judged to be small, so the possibility to trap it
1602 depends on the way perl was compiled. By default it is not trappable.
1603 However, if compiled for this, Perl may use the contents of C<$^M> as
1604 an emergency pool after die()ing with this message. In this case the
1605 error is trappable I<once>.
1607 =item Out of memory during request for %s
1609 (F) The malloc() function returned 0, indicating there was insufficient
1610 remaining memory (or virtual memory) to satisfy the request. However,
1611 the request was judged large enough (compile-time default is 64K), so
1612 a possibility to shut down by trapping this error is granted.
1616 (W) A single call to write() produced more lines than can fit on a page.
1619 =item panic: ck_grep
1621 (P) Failed an internal consistency check trying to compile a grep.
1623 =item panic: ck_split
1625 (P) Failed an internal consistency check trying to compile a split.
1627 =item panic: corrupt saved stack index
1629 (P) The savestack was requested to restore more localized values than there
1630 are in the savestack.
1634 (P) We popped the context stack to an eval context, and then discovered
1635 it wasn't an eval context.
1637 =item panic: do_match
1639 (P) The internal pp_match() routine was called with invalid operational data.
1641 =item panic: do_split
1643 (P) Something terrible went wrong in setting up for the split.
1645 =item panic: do_subst
1647 (P) The internal pp_subst() routine was called with invalid operational data.
1649 =item panic: do_trans
1651 (P) The internal do_trans() routine was called with invalid operational data.
1655 (P) We popped the context stack to a context with the specified label,
1656 and then discovered it wasn't a context we know how to do a goto in.
1658 =item panic: INTERPCASEMOD
1660 (P) The lexer got into a bad state at a case modifier.
1662 =item panic: INTERPCONCAT
1664 (P) The lexer got into a bad state parsing a string with brackets.
1668 (P) We popped the context stack to a block context, and then discovered
1669 it wasn't a block context.
1671 =item panic: leave_scope clearsv
1673 (P) A writable lexical variable became read-only somehow within the scope.
1675 =item panic: leave_scope inconsistency
1677 (P) The savestack probably got out of sync. At least, there was an
1678 invalid enum on the top of it.
1682 (P) Something requested a negative number of bytes of malloc.
1684 =item panic: mapstart
1686 (P) The compiler is screwed up with respect to the map() function.
1688 =item panic: null array
1690 (P) One of the internal array routines was passed a null AV pointer.
1692 =item panic: pad_alloc
1694 (P) The compiler got confused about which scratch pad it was allocating
1695 and freeing temporaries and lexicals from.
1697 =item panic: pad_free curpad
1699 (P) The compiler got confused about which scratch pad it was allocating
1700 and freeing temporaries and lexicals from.
1702 =item panic: pad_free po
1704 (P) An invalid scratch pad offset was detected internally.
1706 =item panic: pad_reset curpad
1708 (P) The compiler got confused about which scratch pad it was allocating
1709 and freeing temporaries and lexicals from.
1711 =item panic: pad_sv po
1713 (P) An invalid scratch pad offset was detected internally.
1715 =item panic: pad_swipe curpad
1717 (P) The compiler got confused about which scratch pad it was allocating
1718 and freeing temporaries and lexicals from.
1720 =item panic: pad_swipe po
1722 (P) An invalid scratch pad offset was detected internally.
1724 =item panic: pp_iter
1726 (P) The foreach iterator got called in a non-loop context frame.
1728 =item panic: realloc
1730 (P) Something requested a negative number of bytes of realloc.
1732 =item panic: restartop
1734 (P) Some internal routine requested a goto (or something like it), and
1735 didn't supply the destination.
1739 (P) We popped the context stack to a subroutine or eval context, and
1740 then discovered it wasn't a subroutine or eval context.
1742 =item panic: scan_num
1744 (P) scan_num() got called on something that wasn't a number.
1746 =item panic: sv_insert
1748 (P) The sv_insert() routine was told to remove more string than there
1751 =item panic: top_env
1753 (P) The compiler attempted to do a goto, or something weird like that.
1757 (P) The lexer got into a bad state while processing a case modifier.
1759 =item Pareneses missing around "%s" list
1761 (W) You said something like
1767 my ($foo, $bar) = @_;
1769 Remember that "my" and "local" bind closer than comma.
1771 =item Perl %3.3f required--this is only version %s, stopped
1773 (F) The module in question uses features of a version of Perl more recent
1774 than the currently running version. How long has it been since you upgraded,
1775 anyway? See L<perlfunc/require>.
1777 =item Permission denied
1779 (F) The setuid emulator in suidperl decided you were up to no good.
1781 =item pid %d not a child
1783 (W) A warning peculiar to VMS. Waitpid() was asked to wait for a process which
1784 isn't a subprocess of the current process. While this is fine from VMS'
1785 perspective, it's probably not what you intended.
1787 =item POSIX getpgrp can't take an argument
1789 (F) Your C compiler uses POSIX getpgrp(), which takes no argument, unlike
1790 the BSD version, which takes a pid.
1792 =item Possible attempt to put comments in qw() list
1794 (W) qw() lists contain items separated by whitespace; as with literal
1795 strings, comment characters are not ignored, but are instead treated
1796 as literal data. (You may have used different delimiters than the
1797 exclamation marks parentheses shown here; braces are also frequently
1800 You probably wrote something like this:
1807 when you should have written this:
1814 If you really want comments, build your list the
1815 old-fashioned way, with quotes and commas:
1819 'b', # another comment
1822 =item Possible attempt to separate words with commas
1824 (W) qw() lists contain items separated by whitespace; therefore commas
1825 aren't needed to separate the items. (You may have used different
1826 delimiters than the parentheses shown here; braces are also frequently
1829 You probably wrote something like this:
1833 which puts literal commas into some of the list items. Write it without
1834 commas if you don't want them to appear in your data:
1838 =item Possible memory corruption: %s overflowed 3rd argument
1840 (F) An ioctl() or fcntl() returned more than Perl was bargaining for.
1841 Perl guesses a reasonable buffer size, but puts a sentinel byte at the
1842 end of the buffer just in case. This sentinel byte got clobbered, and
1843 Perl assumes that memory is now corrupted. See L<perlfunc/ioctl>.
1845 =item Precedence problem: open %s should be open(%s)
1847 (S) The old irregular construct
1851 is now misinterpreted as
1855 because of the strict regularization of Perl 5's grammar into unary
1856 and list operators. (The old open was a little of both.) You must
1857 put parentheses around the filehandle, or use the new "or" operator
1860 =item print on closed filehandle %s
1862 (W) The filehandle you're printing on got itself closed sometime before now.
1863 Check your logic flow.
1865 =item printf on closed filehandle %s
1867 (W) The filehandle you're writing to got itself closed sometime before now.
1868 Check your logic flow.
1870 =item Probable precedence problem on %s
1872 (W) The compiler found a bare word where it expected a conditional,
1873 which often indicates that an || or && was parsed as part of the
1874 last argument of the previous construct, for example:
1878 =item Prototype mismatch: (%s) vs (%s)
1880 (S) The subroutine being defined had a pre-declared (forward) declaration
1881 with a different function prototype.
1883 =item Read on closed filehandle E<lt>%sE<gt>
1885 (W) The filehandle you're reading from got itself closed sometime before now.
1886 Check your logic flow.
1888 =item Reallocation too large: %lx
1890 (F) You can't allocate more than 64K on an MSDOS machine.
1892 =item Recompile perl with B<-D>DEBUGGING to use B<-D> switch
1894 (F) You can't use the B<-D> option unless the code to produce the
1895 desired output is compiled into Perl, which entails some overhead,
1896 which is why it's currently left out of your copy.
1898 =item Recursive inheritance detected
1900 (F) More than 100 levels of inheritance were used. Probably indicates
1901 an unintended loop in your inheritance hierarchy.
1903 =item Reference miscount in sv_replace()
1905 (W) The internal sv_replace() function was handed a new SV with a
1906 reference count of other than 1.
1908 =item regexp memory corruption
1910 (P) The regular expression engine got confused by what the regular
1911 expression compiler gave it.
1913 =item regexp out of space
1915 (P) A "can't happen" error, because safemalloc() should have caught it earlier.
1917 =item regexp too big
1919 (F) The current implementation of regular expressions uses shorts as
1920 address offsets within a string. Unfortunately this means that if
1921 the regular expression compiles to longer than 32767, it'll blow up.
1922 Usually when you want a regular expression this big, there is a better
1923 way to do it with multiple statements. See L<perlre>.
1925 =item Reversed %s= operator
1927 (W) You wrote your assignment operator backwards. The = must always
1928 comes last, to avoid ambiguity with subsequent unary operators.
1930 =item Runaway format
1932 (F) Your format contained the ~~ repeat-until-blank sequence, but it
1933 produced 200 lines at once, and the 200th line looked exactly like the
1934 199th line. Apparently you didn't arrange for the arguments to exhaust
1935 themselves, either by using ^ instead of @ (for scalar variables), or by
1936 shifting or popping (for array variables). See L<perlform>.
1938 =item Scalar value @%s[%s] better written as $%s[%s]
1940 (W) You've used an array slice (indicated by @) to select a single element of
1941 an array. Generally it's better to ask for a scalar value (indicated by $).
1942 The difference is that C<$foo[&bar]> always behaves like a scalar, both when
1943 assigning to it and when evaluating its argument, while C<@foo[&bar]> behaves
1944 like a list when you assign to it, and provides a list context to its
1945 subscript, which can do weird things if you're expecting only one subscript.
1947 On the other hand, if you were actually hoping to treat the array
1948 element as a list, you need to look into how references work, because
1949 Perl will not magically convert between scalars and lists for you. See
1952 =item Scalar value @%s{%s} better written as $%s{%s}
1954 (W) You've used a hash slice (indicated by @) to select a single element of
1955 a hash. Generally it's better to ask for a scalar value (indicated by $).
1956 The difference is that C<$foo{&bar}> always behaves like a scalar, both when
1957 assigning to it and when evaluating its argument, while C<@foo{&bar}> behaves
1958 like a list when you assign to it, and provides a list context to its
1959 subscript, which can do weird things if you're expecting only one subscript.
1961 On the other hand, if you were actually hoping to treat the hash
1962 element as a list, you need to look into how references work, because
1963 Perl will not magically convert between scalars and lists for you. See
1966 =item Script is not setuid/setgid in suidperl
1968 (F) Oddly, the suidperl program was invoked on a script with its setuid
1969 or setgid bit not set. This doesn't make much sense.
1971 =item Search pattern not terminated
1973 (F) The lexer couldn't find the final delimiter of a // or m{}
1974 construct. Remember that bracketing delimiters count nesting level.
1976 =item seek() on unopened file
1978 (W) You tried to use the seek() function on a filehandle that was either
1979 never opened or has been closed since.
1981 =item select not implemented
1983 (F) This machine doesn't implement the select() system call.
1985 =item sem%s not implemented
1987 (F) You don't have System V semaphore IPC on your system.
1989 =item semi-panic: attempt to dup freed string
1991 (S) The internal newSVsv() routine was called to duplicate a scalar
1992 that had previously been marked as free.
1994 =item Semicolon seems to be missing
1996 (W) A nearby syntax error was probably caused by a missing semicolon,
1997 or possibly some other missing operator, such as a comma.
1999 =item Send on closed socket
2001 (W) The filehandle you're sending to got itself closed sometime before now.
2002 Check your logic flow.
2004 =item Sequence (?#... not terminated
2006 (F) A regular expression comment must be terminated by a closing
2007 parenthesis. Embedded parentheses aren't allowed. See L<perlre>.
2009 =item Sequence (?%s...) not implemented
2011 (F) A proposed regular expression extension has the character reserved
2012 but has not yet been written. See L<perlre>.
2014 =item Sequence (?%s...) not recognized
2016 (F) You used a regular expression extension that doesn't make sense.
2021 Also known as "500 Server error".
2023 B<This is a CGI error, not a Perl error>.
2025 You need to make sure your script is executable, is accessible by the user
2026 CGI is running the script under (which is probably not the user account you
2027 tested it under), does not rely on any environment variables (like PATH)
2028 from the user it isn't running under, and isn't in a location where the CGI
2029 server can't find it, basically, more or less. Please see the following
2030 for more information:
2032 http://www.perl.com/perl/faq/idiots-guide.html
2033 http://www.perl.com/perl/faq/perl-cgi-faq.html
2034 ftp://rtfm.mit.edu/pub/usenet/news.answers/www/cgi-faq
2035 http://hoohoo.ncsa.uiuc.edu/cgi/interface.html
2036 http://www-genome.wi.mit.edu/WWW/faqs/www-security-faq.html
2038 =item setegid() not implemented
2040 (F) You tried to assign to C<$)>, and your operating system doesn't support
2041 the setegid() system call (or equivalent), or at least Configure didn't
2044 =item seteuid() not implemented
2046 (F) You tried to assign to C<$E<gt>>, and your operating system doesn't support
2047 the seteuid() system call (or equivalent), or at least Configure didn't
2050 =item setrgid() not implemented
2052 (F) You tried to assign to C<$(>, and your operating system doesn't support
2053 the setrgid() system call (or equivalent), or at least Configure didn't
2056 =item setruid() not implemented
2058 (F) You tried to assign to C<$<lt>>, and your operating system doesn't support
2059 the setruid() system call (or equivalent), or at least Configure didn't
2062 =item Setuid/gid script is writable by world
2064 (F) The setuid emulator won't run a script that is writable by the world,
2065 because the world might have written on it already.
2067 =item shm%s not implemented
2069 (F) You don't have System V shared memory IPC on your system.
2071 =item shutdown() on closed fd
2073 (W) You tried to do a shutdown on a closed socket. Seems a bit superfluous.
2075 =item SIG%s handler "%s" not defined
2077 (W) The signal handler named in %SIG doesn't, in fact, exist. Perhaps you
2078 put it into the wrong package?
2080 =item sort is now a reserved word
2082 (F) An ancient error message that almost nobody ever runs into anymore.
2083 But before sort was a keyword, people sometimes used it as a filehandle.
2085 =item Sort subroutine didn't return a numeric value
2087 (F) A sort comparison routine must return a number. You probably blew
2088 it by not using C<E<lt>=E<gt>> or C<cmp>, or by not using them correctly.
2089 See L<perlfunc/sort>.
2091 =item Sort subroutine didn't return single value
2093 (F) A sort comparison subroutine may not return a list value with more
2094 or less than one element. See L<perlfunc/sort>.
2098 (P) The split was looping infinitely. (Obviously, a split shouldn't iterate
2099 more times than there are characters of input, which is what happened.)
2100 See L<perlfunc/split>.
2102 =item Stat on unopened file E<lt>%sE<gt>
2104 (W) You tried to use the stat() function (or an equivalent file test)
2105 on a filehandle that was either never opened or has been closed since.
2107 =item Statement unlikely to be reached
2109 (W) You did an exec() with some statement after it other than a die().
2110 This is almost always an error, because exec() never returns unless
2111 there was a failure. You probably wanted to use system() instead,
2112 which does return. To suppress this warning, put the exec() in a block
2115 =item Stub found while resolving method `%s' overloading `%s' in package `%s'
2117 (P) Overloading resolution over @ISA tree may be broken by importation stubs.
2118 Stubs should never be implicitely created, but explicit calls to C<can>
2121 =item Subroutine %s redefined
2123 (W) You redefined a subroutine. To suppress this warning, say
2127 eval "sub name { ... }";
2130 =item Substitution loop
2132 (P) The substitution was looping infinitely. (Obviously, a
2133 substitution shouldn't iterate more times than there are characters of
2134 input, which is what happened.) See the discussion of substitution in
2135 L<perlop/"Quote and Quote-like Operators">.
2137 =item Substitution pattern not terminated
2139 (F) The lexer couldn't find the interior delimiter of a s/// or s{}{}
2140 construct. Remember that bracketing delimiters count nesting level.
2142 =item Substitution replacement not terminated
2144 (F) The lexer couldn't find the final delimiter of a s/// or s{}{}
2145 construct. Remember that bracketing delimiters count nesting level.
2147 =item substr outside of string
2149 (W) You tried to reference a substr() that pointed outside of a string.
2150 That is, the absolute value of the offset was larger than the length of
2151 the string. See L<perlfunc/substr>.
2153 =item suidperl is no longer needed since %s
2155 (F) Your Perl was compiled with B<-D>SETUID_SCRIPTS_ARE_SECURE_NOW, but a
2156 version of the setuid emulator somehow got run anyway.
2160 (F) Probably means you had a syntax error. Common reasons include:
2162 A keyword is misspelled.
2163 A semicolon is missing.
2165 An opening or closing parenthesis is missing.
2166 An opening or closing brace is missing.
2167 A closing quote is missing.
2169 Often there will be another error message associated with the syntax
2170 error giving more information. (Sometimes it helps to turn on B<-w>.)
2171 The error message itself often tells you where it was in the line when
2172 it decided to give up. Sometimes the actual error is several tokens
2173 before this, because Perl is good at understanding random input.
2174 Occasionally the line number may be misleading, and once in a blue moon
2175 the only way to figure out what's triggering the error is to call
2176 C<perl -c> repeatedly, chopping away half the program each time to see
2177 if the error went away. Sort of the cybernetic version of S<20 questions>.
2179 =item syntax error at line %d: `%s' unexpected
2181 (A) You've accidentally run your script through the Bourne shell
2182 instead of Perl. Check the #! line, or manually feed your script
2185 =item System V IPC is not implemented on this machine
2187 (F) You tried to do something with a function beginning with "sem", "shm",
2188 or "msg". See L<perlfunc/semctl>, for example.
2190 =item Syswrite on closed filehandle
2192 (W) The filehandle you're writing to got itself closed sometime before now.
2193 Check your logic flow.
2195 =item tell() on unopened file
2197 (W) You tried to use the tell() function on a filehandle that was either
2198 never opened or has been closed since.
2200 =item Test on unopened file E<lt>%sE<gt>
2202 (W) You tried to invoke a file test operator on a filehandle that isn't
2203 open. Check your logic. See also L<perlfunc/-X>.
2205 =item That use of $[ is unsupported
2207 (F) Assignment to C<$[> is now strictly circumscribed, and interpreted as
2208 a compiler directive. You may say only one of
2217 This is to prevent the problem of one module changing the array base
2218 out from under another module inadvertently. See L<perlvar/$[>.
2220 =item The %s function is unimplemented
2222 The function indicated isn't implemented on this architecture, according
2223 to the probings of Configure.
2225 =item The crypt() function is unimplemented due to excessive paranoia
2227 (F) Configure couldn't find the crypt() function on your machine,
2228 probably because your vendor didn't supply it, probably because they
2229 think the U.S. Government thinks it's a secret, or at least that they
2230 will continue to pretend that it is. And if you quote me on that, I
2233 =item The stat preceding C<-l _> wasn't an lstat
2235 (F) It makes no sense to test the current stat buffer for symbolic linkhood
2236 if the last stat that wrote to the stat buffer already went past
2237 the symlink to get to the real file. Use an actual filename instead.
2239 =item times not implemented
2241 (F) Your version of the C library apparently doesn't do times(). I suspect
2242 you're not running on Unix.
2244 =item Too few args to syscall
2246 (F) There has to be at least one argument to syscall() to specify the
2247 system call to call, silly dilly.
2249 =item Too late for "B<-T>" option
2251 (X) The #! line (or local equivalent) in a Perl script contains the
2252 B<-T> option, but Perl was not invoked with B<-T> in its argument
2253 list. This is an error because, by the time Perl discovers a B<-T> in
2254 a script, it's too late to properly taint everything from the
2255 environment. So Perl gives up.
2257 If the Perl script is being executed as a command using the #!
2258 mechanism (or its local equivalent), this error can usually be fixed
2259 by editing the #! line so that the B<-T> option is a part of Perl's
2260 first argument: e.g. change C<perl -n -T> to C<perl -T -n>.
2262 If the Perl script is being executed as C<perl scriptname>, then the
2263 B<-T> option must appear on the command line: C<perl -T scriptname>.
2269 (A) You've accidentally run your script through B<csh> instead
2270 of Perl. Check the #! line, or manually feed your script into
2273 =item Too many args to syscall
2275 (F) Perl supports a maximum of only 14 args to syscall().
2277 =item Too many arguments for %s
2279 (F) The function requires fewer arguments than you specified.
2281 =item trailing \ in regexp
2283 (F) The regular expression ends with an unbackslashed backslash. Backslash
2286 =item Translation pattern not terminated
2288 (F) The lexer couldn't find the interior delimiter of a tr/// or tr[][]
2291 =item Translation replacement not terminated
2293 (F) The lexer couldn't find the final delimiter of a tr/// or tr[][]
2296 =item truncate not implemented
2298 (F) Your machine doesn't implement a file truncation mechanism that
2299 Configure knows about.
2301 =item Type of arg %d to %s must be %s (not %s)
2303 (F) This function requires the argument in that position to be of a
2304 certain type. Arrays must be @NAME or C<@{EXPR}>. Hashes must be
2305 %NAME or C<%{EXPR}>. No implicit dereferencing is allowed--use the
2306 {EXPR} forms as an explicit dereference. See L<perlref>.
2308 =item umask: argument is missing initial 0
2310 (W) A umask of 222 is incorrect. It should be 0222, because octal literals
2311 always start with 0 in Perl, as in C.
2313 =item Unable to create sub named "%s"
2315 (F) You attempted to create or access a subroutine with an illegal name.
2317 =item Unbalanced context: %d more PUSHes than POPs
2319 (W) The exit code detected an internal inconsistency in how many execution
2320 contexts were entered and left.
2322 =item Unbalanced saves: %d more saves than restores
2324 (W) The exit code detected an internal inconsistency in how many
2325 values were temporarily localized.
2327 =item Unbalanced scopes: %d more ENTERs than LEAVEs
2329 (W) The exit code detected an internal inconsistency in how many blocks
2330 were entered and left.
2332 =item Unbalanced tmps: %d more allocs than frees
2334 (W) The exit code detected an internal inconsistency in how many mortal
2335 scalars were allocated and freed.
2337 =item Undefined format "%s" called
2339 (F) The format indicated doesn't seem to exist. Perhaps it's really in
2340 another package? See L<perlform>.
2342 =item Undefined sort subroutine "%s" called
2344 (F) The sort comparison routine specified doesn't seem to exist. Perhaps
2345 it's in a different package? See L<perlfunc/sort>.
2347 =item Undefined subroutine &%s called
2349 (F) The subroutine indicated hasn't been defined, or if it was, it
2350 has since been undefined.
2352 =item Undefined subroutine called
2354 (F) The anonymous subroutine you're trying to call hasn't been defined,
2355 or if it was, it has since been undefined.
2357 =item Undefined subroutine in sort
2359 (F) The sort comparison routine specified is declared but doesn't seem to
2360 have been defined yet. See L<perlfunc/sort>.
2362 =item Undefined top format "%s" called
2364 (F) The format indicated doesn't seem to exist. Perhaps it's really in
2365 another package? See L<perlform>.
2367 =item unexec of %s into %s failed!
2369 (F) The unexec() routine failed for some reason. See your local FSF
2370 representative, who probably put it there in the first place.
2372 =item Unknown BYTEORDER
2374 (F) There are no byte-swapping functions for a machine with this byte order.
2376 =item unmatched () in regexp
2378 (F) Unbackslashed parentheses must always be balanced in regular
2379 expressions. If you're a vi user, the % key is valuable for finding
2380 the matching parenthesis. See L<perlre>.
2382 =item Unmatched right bracket
2384 (F) The lexer counted more closing curly brackets (braces) than opening
2385 ones, so you're probably missing an opening bracket. As a general
2386 rule, you'll find the missing one (so to speak) near the place you were
2389 =item unmatched [] in regexp
2391 (F) The brackets around a character class must match. If you wish to
2392 include a closing bracket in a character class, backslash it or put it first.
2395 =item Unquoted string "%s" may clash with future reserved word
2397 (W) You used a bare word that might someday be claimed as a reserved word.
2398 It's best to put such a word in quotes, or capitalize it somehow, or insert
2399 an underbar into it. You might also declare it as a subroutine.
2401 =item Unrecognized character \%03o ignored
2403 (S) A garbage character was found in the input, and ignored, in case it's
2404 a weird control character on an EBCDIC machine, or some such.
2406 =item Unrecognized signal name "%s"
2408 (F) You specified a signal name to the kill() function that was not recognized.
2409 Say C<kill -l> in your shell to see the valid signal names on your system.
2411 =item Unrecognized switch: -%s
2413 (F) You specified an illegal option to Perl. Don't do that.
2414 (If you think you didn't do that, check the #! line to see if it's
2415 supplying the bad switch on your behalf.)
2417 =item Unsuccessful %s on filename containing newline
2419 (W) A file operation was attempted on a filename, and that operation
2420 failed, PROBABLY because the filename contained a newline, PROBABLY
2421 because you forgot to chop() or chomp() it off. See L<perlfunc/chop>.
2423 =item Unsupported directory function "%s" called
2425 (F) Your machine doesn't support opendir() and readdir().
2427 =item Unsupported function %s
2429 (F) This machines doesn't implement the indicated function, apparently.
2430 At least, Configure doesn't think so.
2432 =item Unsupported socket function "%s" called
2434 (F) Your machine doesn't support the Berkeley socket mechanism, or at
2435 least that's what Configure thought.
2437 =item Unterminated E<lt>E<gt> operator
2439 (F) The lexer saw a left angle bracket in a place where it was expecting
2440 a term, so it's looking for the corresponding right angle bracket, and not
2441 finding it. Chances are you left some needed parentheses out earlier in
2442 the line, and you really meant a "less than".
2444 =item Use of $# is deprecated
2446 (D) This was an ill-advised attempt to emulate a poorly defined B<awk> feature.
2447 Use an explicit printf() or sprintf() instead.
2449 =item Use of $* is deprecated
2451 (D) This variable magically turned on multi-line pattern matching, both for
2452 you and for any luckless subroutine that you happen to call. You should
2453 use the new C<//m> and C<//s> modifiers now to do that without the dangerous
2454 action-at-a-distance effects of C<$*>.
2456 =item Use of %s in printf format not supported
2458 (F) You attempted to use a feature of printf that is accessible from
2459 only C. This usually means there's a better way to do it in Perl.
2461 =item Use of %s is deprecated
2463 (D) The construct indicated is no longer recommended for use, generally
2464 because there's a better way to do it, and also because the old way has
2467 =item Use of bare E<lt>E<lt> to mean E<lt>E<lt>"" is deprecated
2469 (D) You are now encouraged to use the explicitly quoted form if you
2470 wish to use a blank line as the terminator of the here-document.
2472 =item Use of implicit split to @_ is deprecated
2474 (D) It makes a lot of work for the compiler when you clobber a
2475 subroutine's argument list, so it's better if you assign the results of
2476 a split() explicitly to an array (or list).
2478 =item Use of uninitialized value
2480 (W) An undefined value was used as if it were already defined. It was
2481 interpreted as a "" or a 0, but maybe it was a mistake. To suppress this
2482 warning assign an initial value to your variables.
2484 =item Useless use of %s in void context
2486 (W) You did something without a side effect in a context that does nothing
2487 with the return value, such as a statement that doesn't return a value
2488 from a block, or the left side of a scalar comma operator. Very often
2489 this points not to stupidity on your part, but a failure of Perl to parse
2490 your program the way you thought it would. For example, you'd get this
2491 if you mixed up your C precedence with Python precedence and said
2495 when you meant to say
2497 ($one, $two) = (1, 2);
2499 Another common error is to use ordinary parentheses to construct a list
2500 reference when you should be using square or curly brackets, for
2505 when you should have said
2509 The square brackets explicitly turn a list value into a scalar value,
2510 while parentheses do not. So when a parenthesized list is evaluated in
2511 a scalar context, the comma is treated like C's comma operator, which
2512 throws away the left argument, which is not what you want. See
2513 L<perlref> for more on this.
2515 =item untie attempted while %d inner references still exist
2517 (W) A copy of the object returned from C<tie> (or C<tied>) was still
2518 valid when C<untie> was called.
2520 =item Value of %s can be "0"; test with defined()
2522 (W) In a conditional expression, you used <HANDLE>, <*> (glob), C<each()>,
2523 or C<readdir()> as a boolean value. Each of these constructs can return a
2524 value of "0"; that would make the conditional expression false, which is
2525 probably not what you intended. When using these constructs in conditional
2526 expressions, test their values with the C<defined> operator.
2528 =item Variable "%s" is not imported%s
2530 (F) While "use strict" in effect, you referred to a global variable
2531 that you apparently thought was imported from another module, because
2532 something else of the same name (usually a subroutine) is exported
2533 by that module. It usually means you put the wrong funny character
2534 on the front of your variable.
2536 =item Variable "%s" may be unavailable
2538 (W) An inner (nested) I<anonymous> subroutine is inside a I<named>
2539 subroutine, and outside that is another subroutine; and the anonymous
2540 (innermost) subroutine is referencing a lexical variable defined in
2541 the outermost subroutine. For example:
2543 sub outermost { my $a; sub middle { sub { $a } } }
2545 If the anonymous subroutine is called or referenced (directly or
2546 indirectly) from the outermost subroutine, it will share the variable
2547 as you would expect. But if the anonymous subroutine is called or
2548 referenced when the outermost subroutine is not active, it will see
2549 the value of the shared variable as it was before and during the
2550 *first* call to the outermost subroutine, which is probably not what
2553 In these circumstances, it is usually best to make the middle
2554 subroutine anonymous, using the C<sub {}> syntax. Perl has specific
2555 support for shared variables in nested anonymous subroutines; a named
2556 subroutine in between interferes with this feature.
2558 =item Variable "%s" will not stay shared
2560 (W) An inner (nested) I<named> subroutine is referencing a lexical
2561 variable defined in an outer subroutine.
2563 When the inner subroutine is called, it will probably see the value of
2564 the outer subroutine's variable as it was before and during the
2565 *first* call to the outer subroutine; in this case, after the first
2566 call to the outer subroutine is complete, the inner and outer
2567 subroutines will no longer share a common value for the variable. In
2568 other words, the variable will no longer be shared.
2570 Furthermore, if the outer subroutine is anonymous and references a
2571 lexical variable outside itself, then the outer and inner subroutines
2572 will I<never> share the given variable.
2574 This problem can usually be solved by making the inner subroutine
2575 anonymous, using the C<sub {}> syntax. When inner anonymous subs that
2576 reference variables in outer subroutines are called or referenced,
2577 they are automatically re-bound to the current values of such
2580 =item Variable syntax
2582 (A) You've accidentally run your script through B<csh> instead
2583 of Perl. Check the #! line, or manually feed your script into
2586 =item Warning: something's wrong
2588 (W) You passed warn() an empty string (the equivalent of C<warn "">) or
2589 you called it with no args and C<$_> was empty.
2591 =item Warning: unable to close filehandle %s properly
2593 (S) The implicit close() done by an open() got an error indication on the
2594 close(). This usually indicates your file system ran out of disk space.
2596 =item Warning: Use of "%s" without parentheses is ambiguous
2598 (S) You wrote a unary operator followed by something that looks like a
2599 binary operator that could also have been interpreted as a term or
2600 unary operator. For instance, if you know that the rand function
2601 has a default argument of 1.0, and you write
2605 you may THINK you wrote the same thing as
2609 but in actual fact, you got
2613 So put in parentheses to say what you really mean.
2615 =item Write on closed filehandle
2617 (W) The filehandle you're writing to got itself closed sometime before now.
2618 Check your logic flow.
2620 =item X outside of string
2622 (F) You had a pack template that specified a relative position before
2623 the beginning of the string being unpacked. See L<perlfunc/pack>.
2625 =item x outside of string
2627 (F) You had a pack template that specified a relative position after
2628 the end of the string being unpacked. See L<perlfunc/pack>.
2630 =item Xsub "%s" called in sort
2632 (F) The use of an external subroutine as a sort comparison is not yet supported.
2634 =item Xsub called in sort
2636 (F) The use of an external subroutine as a sort comparison is not yet supported.
2638 =item You can't use C<-l> on a filehandle
2640 (F) A filehandle represents an opened file, and when you opened the file it
2641 already went past any symlink you are presumably trying to look for.
2642 Use a filename instead.
2644 =item YOU HAVEN'T DISABLED SET-ID SCRIPTS IN THE KERNEL YET!
2646 (F) And you probably never will, because you probably don't have the
2647 sources to your kernel, and your vendor probably doesn't give a rip
2648 about what you want. Your best bet is to use the wrapsuid script in
2649 the eg directory to put a setuid C wrapper around your script.
2651 =item You need to quote "%s"
2653 (W) You assigned a bareword as a signal handler name. Unfortunately, you
2654 already have a subroutine of that name declared, which means that Perl 5
2655 will try to call the subroutine when the assignment is executed, which is
2656 probably not what you want. (If it IS what you want, put an & in front.)
2658 =item [gs]etsockopt() on closed fd
2660 (W) You tried to get or set a socket option on a closed socket.
2661 Did you forget to check the return value of your socket() call?
2662 See L<perlfunc/getsockopt>.
2664 =item \1 better written as $1
2666 (W) Outside of patterns, backreferences live on as variables. The use
2667 of backslashes is grandfathered on the right-hand side of a
2668 substitution, but stylistically it's better to use the variable form
2669 because other Perl programmers will expect it, and it works better
2670 if there are more than 9 backreferences.
2672 =item '|' and 'E<lt>' may not both be specified on command line
2674 (F) An error peculiar to VMS. Perl does its own command line redirection, and
2675 found that STDIN was a pipe, and that you also tried to redirect STDIN using
2676 'E<lt>'. Only one STDIN stream to a customer, please.
2678 =item '|' and 'E<gt>' may not both be specified on command line
2680 (F) An error peculiar to VMS. Perl does its own command line redirection, and
2681 thinks you tried to redirect stdout both to a file and into a pipe to another
2682 command. You need to choose one or the other, though nothing's stopping you
2683 from piping into a program or Perl script which 'splits' output into two
2686 open(OUT,">$ARGV[0]") or die "Can't write to $ARGV[0]: $!";
2693 =item Got an error from DosAllocMem
2695 (P) An error peculiar to OS/2. Most probably you're using an obsolete
2696 version of Perl, and this should not happen anyway.
2698 =item Malformed PERLLIB_PREFIX
2700 (F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form
2708 with non-empty prefix1 and prefix2. If C<prefix1> is indeed a prefix of
2709 a builtin library search path, prefix2 is substituted. The error may appear
2710 if components are not found, or are too long. See L<perlos2/"PERLLIB_PREFIX">.
2712 =item PERL_SH_DIR too long
2714 (F) An error peculiar to OS/2. PERL_SH_DIR is the directory to find the
2715 C<sh>-shell in. See L<perlos2/"PERL_SH_DIR">.
2717 =item Process terminated by SIG%s
2719 (W) This is a standard message issued by OS/2 applications, while *nix
2720 applications die in silence. It is considered a feature of the OS/2
2721 port. One can easily disable this by appropriate sighandlers, see
2722 L<perlipc/"Signals">. See L<perlos2/"Process terminated by SIGTERM/SIGINT">.