+//depot/perl/pod/perldiag.pod#272 - edit change 14824 (text)
=head1 NAME
perldiag - various Perl diagnostics
must either both be scalars or both be lists. Otherwise Perl won't
know which context to supply to the right side.
-=item Negative offset to vec in lvalue context
+=item Attempt to access key '%_' in fixed hash
-(F) When C<vec> is called in an lvalue context, the second argument must be
-greater than or equal to zero.
+(F) A hash has been marked as READONLY at the C level to turn it
+into a "record" with a fixed set of keys. The failing code
+has attempted to get or set the value of a key which does not
+exist or to delete a key.
=item Attempt to bless into a reference
=item Can't declare class for non-scalar %s in "%s"
-(S) Currently, only scalar variables can declared with a specific class
-qualifier in a "my" or "our" declaration. The semantics may be extended
-for other types of variables in future.
+(F) Currently, only scalar variables can be declared with a specific
+class qualifier in a "my" or "our" declaration. The semantics may be
+extended for other types of variables in future.
=item Can't declare %s in "%s"
=item Can't exec "%s": %s
-(W exec) An system(), exec(), or piped open call could not execute the
+(W exec) A system(), exec(), or piped open call could not execute the
named program for the indicated reason. Typical reasons include: the
permissions were wrong on the file, the file wasn't found in
C<$ENV{PATH}>, the executable in question was compiled for another
checks for an undefined I<scalar> value. If you want to see if the hash
is empty, just use C<if (%hash) { # not empty }> for example.
+=item %s defines neither package nor VERSION--version check failed
+
+(F) You said something like "use Module 42" but in the Module file
+there are neither package declarations nor a C<$VERSION>.
+
=item Delimiter for here document is too long
(F) In a here document construct like C<<<FOO>, the label C<FOO> is too
See Server error.
+=item %s does not define %s::VERSION--version check failed
+
+(F) You said something like "use Module 42" but the Module did not
+define a C<$VERSION.>
+
=item Don't know how to handle magic of type '%s'
(P) The internal handling of magical variables has been cursed.
subroutine or package before the current location. You can use an empty
"sub foo;" or "package FOO;" to enter a "forward" declaration.
+=item dump() better written as CORE::dump()
+
+(W misc) You used the obsolescent C<dump()> built-in function, without fully
+qualifying it as C<CORE::dump()>. Maybe it's a typo. See L<perlfunc/dump>.
+
=item Duplicate free() ignored
(S malloc) An internal routine called free() on something that had
filenames, try using the glob() operator, or put the filenames into a
variable and glob that.
+=item exec? I'm not *that* kind of operating system
+
+(F) The C<exec> function is not implemented in MacPerl. See L<perlport>.
+
=item Execution of %s aborted due to compilation errors
(F) The final summary message when a Perl compilation fails.
(W redefine) You redefined a format. To suppress this warning, say
{
- no warnings;
+ no warnings 'redefine';
eval "format NAME =...";
}
(F) Unlike with "next" or "last", you're not allowed to goto an
unspecified destination. See L<perlfunc/goto>.
+=item %s-group starts with a count
+
+(F) In pack/unpack a ()-group started with a count. A count is
+supposed to follow something: a template character or a ()-group.
+
=item %s had compilation errors
(F) The final summary message when a C<perl -c> fails.
version of Perl appears to have been built without this support. Talk
to your Perl administrator.
+=item Illegal character in prototype for %s : %s
+
+(W syntax) An illegal character was found in a prototype declaration. Legal
+characters in prototypes are $, @, %, *, ;, [, ], &, and \.
+
=item Illegal division by zero
(F) You tried to divide a number by 0. Either something was wrong in
=item Illegal octal digit %s
-(F) You used an 8 or 9 in a octal number.
+(F) You used an 8 or 9 in an octal number.
=item Illegal octal digit %s ignored
-(W digit) You may have tried to use an 8 or 9 in a octal number.
+(W digit) You may have tried to use an 8 or 9 in an octal number.
Interpretation of the octal number stopped before the 8 or 9.
=item Illegal switch in PERL5OPT: %s
(X) The PERL5OPT environment variable may only be used to set the
-following switches: B<-[DIMUdmw]>.
+following switches: B<-[DIMUdmtw]>.
=item Ill-formed CRTL environ value "%s"
Failure of user callbacks dispatched using the C<G_KEEPERR> flag could
also result in this warning. See L<perlcall/G_KEEPERR>.
+=item In EBCDIC the v-string components cannot exceed 2147483647
+
+(F) An error peculiar to EBCDIC. Internally, v-strings are stored as
+Unicode code points, and encoded in EBCDIC as UTF-EBCDIC. The UTF-EBCDIC
+encoding is limited to code points no larger than 2147483647 (0x7FFFFFFF).
+
=item Insecure dependency in %s
(F) You tried to do something that the tainting mechanism didn't like.
=item `%s' is not a code reference
-(W) The second (fourth, sixth, ...) argument of overload::constant needs
-to be a code reference. Either an anonymous subroutine, or a reference
+(W overload) The second (fourth, sixth, ...) argument of overload::constant
+needs to be a code reference. Either an anonymous subroutine, or a reference
to a subroutine.
=item `%s' is not an overloadable type
-(W) You tried to overload a constant type the overload package is unaware of.
+(W overload) You tried to overload a constant type the overload package is
+unaware of.
=item junk on end of regexp
=item lstat() on filehandle %s
-(W io) You tried to do a lstat on a filehandle. What did you mean
+(W io) You tried to do an lstat on a filehandle. What did you mean
by that? lstat() makes sense only on filenames. (Perl did a fstat()
instead on the filehandle.)
appear if components are not found, or are too long. See
"PERLLIB_PREFIX" in L<perlos2>.
+=item Malformed prototype for %s: %s
+
+(F) You tried to use a function with a malformed prototype. The
+syntax of function prototypes is given a brief compile-time check for
+obvious errors like invalid characters. A more rigorous check is run
+when the function is called.
+
=item Malformed UTF-8 character (%s)
Perl detected something that didn't comply with UTF-8 encoding rules.
you omitted the name of the module. Consult L<perlrun> for full details
about C<-M> and C<-m>.
+=item More than one argument to open
+
+(F) The C<open> function has been asked to open multiple files. This
+can happen if you are trying to open a pipe to a command that takes a
+list of arguments, but have forgotten to specify a piped open mode.
+See L<perlfunc/open> for details.
+
=item msg%s not implemented
(F) You don't have System V message IPC on your system.
(F) You tried to do a read/write/send/recv operation with a buffer
length that is less than 0. This is difficult to imagine.
+=item Negative offset to vec in lvalue context
+
+(F) When C<vec> is called in an lvalue context, the second argument must be
+greater than or equal to zero.
+
=item Nested quantifiers in regex; marked by <-- HERE in m/%s/
(F) You can't quantify a quantifier without intervening parentheses. So
(F) The indicated command line switch needs a mandatory argument, but
you haven't specified one.
+=item No such class %s
+
+(F) You provided a class qualifier in a "my" or "our" declaration, but
+this class doesn't exist at this point in your program.
+
=item No such pipe open
(P) An error peculiar to VMS. The internal routine my_pclose() tried to
of Perl. Check the #! line, or manually feed your script into Perl
yourself.
+=item %s not allowed in length fields
+
+(F) The count in the (un)pack template may be replaced by C<[TEMPLATE]> only if
+C<TEMPLATE> always matches the same amount of packed bytes. Redesign
+the template.
+
=item no UTC offset information; assuming local time is UTC
(S) A warning peculiar to VMS. Perl was unable to find the local
=item Odd number of arguments for overload::constant
-(W) The call to overload::constant contained an odd number of arguments.
-The arguments should come in pairs.
+(W overload) The call to overload::constant contained an odd number of
+arguments. The arguments should come in pairs.
+
+=item Odd number of elements in anonymous hash
+
+(W misc) You specified an odd number of elements to initialize a hash,
+which is odd, because hashes come in key/value pairs.
=item Odd number of elements in hash assignment
some day, even though it doesn't yet. Perhaps you should use a
mixed-case attribute name, instead. See L<attributes>.
-=item Package '%s' not found (did you use the incorrect case?)
-
-(W misc) You included a package file via C<use>, but the package name
-did not match the file name. It's possible that you misspelled the
-package name.
-
=item page overflow
(W io) A single call to write() produced more lines than can fit on a
(P) We popped the context stack to an eval context, and then discovered
it wasn't an eval context.
-=item panic: pp_match
+=item panic: pp_match%s
(P) The internal pp_match() routine was called with invalid operational
data.
=item perlio: invalid separator character %s in attribute list
(S) When pushing layers onto the Perl I/O system, something other than a
-colon or whitespace was seen between the elements of an layer list.
+colon or whitespace was seen between the elements of a layer list.
If the previous attribute had a parenthesised parameter list, perhaps that
list was terminated too soon.
process which isn't a subprocess of the current process. While this is
fine from VMS' perspective, it's probably not what you intended.
+=item P must have an explicit size
+
+(F) The unpack format P must have an explicit size, not "*".
+
=item POSIX syntax [%s] belongs inside character classes in regex;
marked by <-- HERE in m/%s/
-(W unsafe) The character class constructs [: :], [= =], and [. .] go
+(W regexp) The character class constructs [: :], [= =], and [. .] go
I<inside> character classes, the [] are part of the construct, for example:
/[012[:alpha:]345]/. Note that [= =] and [. .] are not currently
implemented; they are simply placeholders for future extensions and will
(F) The class in the character class [: :] syntax is unknown. The <-- HERE
shows in the regular expression about where the problem was discovered.
-See L<perlre>.
+Note that the POSIX character classes do B<not> have the C<is> prefix
+the corresponding C interfaces have: in other words, it's C<[[:print:]]>,
+not C<isprint>. See L<perlre>.
=item POSIX getpgrp can't take an argument
=item Prototype mismatch: %s vs %s
-(S unsafe) The subroutine being declared or defined had previously been
+(S prototype) The subroutine being declared or defined had previously been
declared or defined with a different function prototype.
+=item Prototype not terminated
+
+(F) You've omitted the closing parenthesis in a function prototype
+definition.
+
=item Quantifier in {,} bigger than %d in regex;
marked by <-- HERE in m/%s/
location where the CGI server can't find it, basically, more or less.
Please see the following for more information:
- http://www.perl.com/CPAN/doc/FAQs/cgi/idiots-guide.html
- http://www.perl.com/CPAN/doc/FAQs/cgi/perl-cgi-faq.html
- ftp://rtfm.mit.edu/pub/usenet/news.answers/www/cgi-faq
- http://hoohoo.ncsa.uiuc.edu/cgi/interface.html
- http://www-genome.wi.mit.edu/WWW/faqs/www-security-faq.html
+ http://www.perl.org/CGI_MetaFAQ.html
+ http://www.htmlhelp.org/faq/cgifaq.html
+ http://www.w3.org/Security/Faq/
You should also look at L<perlfaq9>.
(F) A sort comparison subroutine may not return a list value with more
or less than one element. See L<perlfunc/sort>.
+=item splice() offset past end of array
+
+(W misc) You attempted to specify an offset that was past the end of
+the array passed to splice(). Splicing will instead commence at the end
+of the array, rather than past it. If this isn't what you want, try
+explicitly pre-extending the array by assigning $#array = $offset. See
+L<perlfunc/splice>.
+
=item Split loop
(P) The split was looping infinitely. (Obviously, a split shouldn't
(W redefine) You redefined a subroutine. To suppress this warning, say
{
- no warnings;
+ no warnings 'redefine';
eval "sub name { ... }";
}
=item Substitution pattern not terminated
-(F) The lexer couldn't find the interior delimiter of a s/// or s{}{}
+(F) The lexer couldn't find the interior delimiter of an s/// or s{}{}
construct. Remember that bracketing delimiters count nesting level.
Missing the leading C<$> from variable C<$s> may cause this error.
=item Substitution replacement not terminated
-(F) The lexer couldn't find the final delimiter of a s/// or s{}{}
+(F) The lexer couldn't find the final delimiter of an s/// or s{}{}
construct. Remember that bracketing delimiters count nesting level.
Missing the leading C<$> from variable C<$s> may cause this error.
=item Too many )'s
+=item Too many ('s
+
(A) You've accidentally run your script through B<csh> instead of Perl.
Check the #! line, or manually feed your script into Perl yourself.
-=item Too many ('s
-
=item Trailing \ in regex m/%s/
(F) The regular expression ends with an unbackslashed backslash.
(F) The unexec() routine failed for some reason. See your local FSF
representative, who probably put it there in the first place.
+=item Unicode character %s is illegal
+
+(W utf8) Certain Unicode characters have been designated off-limits by
+the Unicode standard and should not be generated. If you really know
+what you are doing you can turn off this warning by C<no warnings 'utf8';>.
=item Unknown BYTEORDER
data Perl expected. Someone's very confused, or perhaps trying to
subvert Perl's population of %ENV for nefarious purposes.
+=item Unknown warnings category '%s'
+
+(F) An error issued by the C<warnings> pragma. You specified a warnings
+category that is unknown to perl at this point.
+
+Note that if you want to enable a warnings category registered by a module
+(e.g. C<use warnings 'File::Find'>), you must have imported this module
+first.
+
=item unmatched [ in regex; marked by <-- HERE in m/%s/
(F) The brackets around a character class must match. If you wish to
(W) You did C<use re;> without any arguments. That isn't very useful.
+=item Useless use of sort in scalar context
+
+(W void) You used sort in scalar context, as in :
+
+ my $x = sort @y;
+
+This is not very useful, and perl currently optimizes this away.
+
=item Useless use of %s with no values
(W syntax) You used the push() or unshift() function with no arguments
you should remove AutoLoader from @ISA and change C<use AutoLoader;> to
C<use AutoLoader 'AUTOLOAD';>.
+=item Use of -l on filehandle %s
+
+(W io) A filehandle represents an opened file, and when you opened the file
+it already went past any symlink you are presumably trying to look for.
+The operation returned C<undef>. Use a filename instead.
+
=item Use of "package" with no arguments is deprecated
(D deprecated) You used the C<package> keyword without specifying a package
suppressed for subroutine names by either adding a C<&> prefix, or using
a package qualifier, e.g. C<&our()>, or C<Foo::our()>.
+=item Use of tainted arguments in %s is deprecated
+
+(W taint) You have supplied C<system()> or C<exec()> with multiple
+arguments and at least one of them is tainted. This used to be allowed
+but will become a fatal error in a future version of perl. Untaint your
+arguments. See L<perlsec>.
+
=item Use of uninitialized value%s
(W uninitialized) An undefined value was used as if it were already
=item Using a hash as a reference is deprecated
(D deprecated) You tried to use a hash as a reference, as in
-C<< %foo->{"bar"} >> or C<< %$ref->{"hello"} >>. Versions of perl <= 5.6.1
-used to allow this syntax, but shouldn't have. It is now deprecated, and will
+C<< %foo->{"bar"} >> or C<< %$ref->{"hello"} >>. Versions of perl <= 5.6.1
+used to allow this syntax, but shouldn't have. It is now deprecated, and will
be removed in a future version.
=item Using an array as a reference is deprecated
(D deprecated) You tried to use an array as a reference, as in
-C<< @foo->[23] >> or C<< @$ref->[99] >>. Versions of perl <= 5.6.1 used to
-allow this syntax, but shouldn't have. It is now deprecated, and will be
+C<< @foo->[23] >> or C<< @$ref->[99] >>. Versions of perl <= 5.6.1 used to
+allow this syntax, but shouldn't have. It is now deprecated, and will be
removed in a future version.
+=item UTF-16 surrogate %s
+
+(W utf8) You tried to generate half of an UTF-16 surrogate by
+requesting a Unicode character between the code points 0xD800 and
+0xDFFF (inclusive). That range is reserved exclusively for the use of
+UTF-16 encoding (by having two 16-bit UCS-2 characters); but Perl
+encodes its characters in UTF-8, so what you got is a very illegal
+character. If you really know what you are doing you can turn off
+this warning by C<no warnings 'utf8';>.
+
=item Value of %s can be "0"; test with defined()
(W misc) In a conditional expression, you used <HANDLE>, <*> (glob),
=item Wide character in %s
-(W utf8) Perl met a wide character (>255) when it wasn't expecting one.
+(W utf8) Perl met a wide character (>255) when it wasn't expecting
+one. This warning is by default on for I/O (like print) but can be
+turned off by C<no warnings 'utf8';>. You are supposed to explicitly
+mark the filehandle with an encoding, see L<open> and L<perlfunc/binmode>.
=item write() on closed filehandle %s
(F) The use of an external subroutine as a sort comparison is not yet
supported.
-=item You can't use C<-l> on a filehandle
-
-(F) A filehandle represents an opened file, and when you opened the file
-it already went past any symlink you are presumably trying to look for.
-Use a filename instead.
-
=item YOU HAVEN'T DISABLED SET-ID SCRIPTS IN THE KERNEL YET!
(F) And you probably never will, because you probably don't have the
sources to your kernel, and your vendor probably doesn't give a rip
-about what you want. Your best bet is to put a setuid C wrapper around
+about what you want. Your best bet is to put a setuid C wrapper around
your script.
=item You need to quote "%s"
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