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authorNorbert Preining <preining@logic.at>2010-05-12 16:54:37 +0000
committerNorbert Preining <preining@logic.at>2010-05-12 16:54:37 +0000
commit661c41a09e39a182865e0b51e34cc995a0dc96e8 (patch)
tree2f79bb1406e22fdcb2587be8ffda6c0c609d7932 /Master/tlpkg/tlperl/lib/pods/perldiag.pod
parentb645030efc22e13c2498a1522083634ab91b2de1 (diff)
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+=head1 NAME
+
+perldiag - various Perl diagnostics
+
+=head1 DESCRIPTION
+
+These messages are classified as follows (listed in increasing order of
+desperation):
+
+ (W) A warning (optional).
+ (D) A deprecation (optional).
+ (S) A severe warning (enabled by default).
+ (F) A fatal error (trappable).
+ (P) An internal error you should never see (trappable).
+ (X) A very fatal error (nontrappable).
+ (A) An alien error message (not generated by Perl).
+
+The majority of messages from the first three classifications above
+(W, D & S) can be controlled using the C<warnings> pragma.
+
+If a message can be controlled by the C<warnings> pragma, its warning
+category is included with the classification letter in the description
+below.
+
+Optional warnings are enabled by using the C<warnings> pragma or the B<-w>
+and B<-W> switches. Warnings may be captured by setting C<$SIG{__WARN__}>
+to a reference to a routine that will be called on each warning instead
+of printing it. See L<perlvar>.
+
+Severe warnings are always enabled, unless they are explicitly disabled
+with the C<warnings> pragma or the B<-X> switch.
+
+Trappable errors may be trapped using the eval operator. See
+L<perlfunc/eval>. In almost all cases, warnings may be selectively
+disabled or promoted to fatal errors using the C<warnings> pragma.
+See L<warnings>.
+
+The messages are in alphabetical order, without regard to upper or
+lower-case. Some of these messages are generic. Spots that vary are
+denoted with a %s or other printf-style escape. These escapes are
+ignored by the alphabetical order, as are all characters other than
+letters. To look up your message, just ignore anything that is not a
+letter.
+
+=over 4
+
+=item accept() on closed socket %s
+
+(W closed) You tried to do an accept on a closed socket. Did you forget
+to check the return value of your socket() call? See
+L<perlfunc/accept>.
+
+=item Allocation too large: %lx
+
+(X) You can't allocate more than 64K on an MS-DOS machine.
+
+=item '%c' allowed only after types %s
+
+(F) The modifiers '!', '<' and '>' are allowed in pack() or unpack() only
+after certain types. See L<perlfunc/pack>.
+
+=item Ambiguous call resolved as CORE::%s(), qualify as such or use &
+
+(W ambiguous) A subroutine you have declared has the same name as a Perl
+keyword, and you have used the name without qualification for calling
+one or the other. Perl decided to call the builtin because the
+subroutine is not imported.
+
+To force interpretation as a subroutine call, either put an ampersand
+before the subroutine name, or qualify the name with its package.
+Alternatively, you can import the subroutine (or pretend that it's
+imported with the C<use subs> pragma).
+
+To silently interpret it as the Perl operator, use the C<CORE::> prefix
+on the operator (e.g. C<CORE::log($x)>) or declare the subroutine
+to be an object method (see L<perlsub/"Subroutine Attributes"> or
+L<attributes>).
+
+=item Ambiguous range in transliteration operator
+
+(F) You wrote something like C<tr/a-z-0//> which doesn't mean anything at
+all. To include a C<-> character in a transliteration, put it either
+first or last. (In the past, C<tr/a-z-0//> was synonymous with
+C<tr/a-y//>, which was probably not what you would have expected.)
+
+=item Ambiguous use of %s resolved as %s
+
+(W ambiguous)(S) You said something that may not be interpreted the way
+you thought. Normally it's pretty easy to disambiguate it by supplying
+a missing quote, operator, parenthesis pair or declaration.
+
+=item '|' and '<' may not both be specified on command line
+
+(F) An error peculiar to VMS. Perl does its own command line
+redirection, and found that STDIN was a pipe, and that you also tried to
+redirect STDIN using '<'. Only one STDIN stream to a customer, please.
+
+=item '|' and '>' may not both be specified on command line
+
+(F) An error peculiar to VMS. Perl does its own command line
+redirection, and thinks you tried to redirect stdout both to a file and
+into a pipe to another command. You need to choose one or the other,
+though nothing's stopping you from piping into a program or Perl script
+which 'splits' output into two streams, such as
+
+ open(OUT,">$ARGV[0]") or die "Can't write to $ARGV[0]: $!";
+ while (<STDIN>) {
+ print;
+ print OUT;
+ }
+ close OUT;
+
+=item Applying %s to %s will act on scalar(%s)
+
+(W misc) The pattern match (C<//>), substitution (C<s///>), and
+transliteration (C<tr///>) operators work on scalar values. If you apply
+one of them to an array or a hash, it will convert the array or hash to
+a scalar value -- the length of an array, or the population info of a
+hash -- and then work on that scalar value. This is probably not what
+you meant to do. See L<perlfunc/grep> and L<perlfunc/map> for
+alternatives.
+
+=item Args must match #! line
+
+(F) The setuid emulator requires that the arguments Perl was invoked
+with match the arguments specified on the #! line. Since some systems
+impose a one-argument limit on the #! line, try combining switches;
+for example, turn C<-w -U> into C<-wU>.
+
+=item Arg too short for msgsnd
+
+(F) msgsnd() requires a string at least as long as sizeof(long).
+
+=item %s argument is not a HASH or ARRAY element or a subroutine
+
+(F) The argument to exists() must be a hash or array element or a
+subroutine with an ampersand, such as:
+
+ $foo{$bar}
+ $ref->{"susie"}[12]
+ &do_something
+
+=item %s argument is not a HASH or ARRAY element or slice
+
+(F) The argument to delete() must be either a hash or array element,
+such as:
+
+ $foo{$bar}
+ $ref->{"susie"}[12]
+
+or a hash or array slice, such as:
+
+ @foo[$bar, $baz, $xyzzy]
+ @{$ref->[12]}{"susie", "queue"}
+
+=item %s argument is not a subroutine name
+
+(F) The argument to exists() for C<exists &sub> must be a subroutine
+name, and not a subroutine call. C<exists &sub()> will generate this
+error.
+
+=item Argument "%s" isn't numeric%s
+
+(W numeric) The indicated string was fed as an argument to an operator
+that expected a numeric value instead. If you're fortunate the message
+will identify which operator was so unfortunate.
+
+=item Argument list not closed for PerlIO layer "%s"
+
+(W layer) When pushing a layer with arguments onto the Perl I/O system you
+forgot the ) that closes the argument list. (Layers take care of transforming
+data between external and internal representations.) Perl stopped parsing
+the layer list at this point and did not attempt to push this layer.
+If your program didn't explicitly request the failing operation, it may be
+the result of the value of the environment variable PERLIO.
+
+=item Array @%s missing the @ in argument %d of %s()
+
+(D deprecated) Really old Perl let you omit the @ on array names in some
+spots. This is now heavily deprecated.
+
+=item assertion botched: %s
+
+(P) The malloc package that comes with Perl had an internal failure.
+
+=item Assertion failed: file "%s"
+
+(P) A general assertion failed. The file in question must be examined.
+
+=item Assignment to both a list and a scalar
+
+(F) If you assign to a conditional operator, the 2nd and 3rd arguments
+must either both be scalars or both be lists. Otherwise Perl won't
+know which context to supply to the right side.
+
+=item A thread exited while %d threads were running
+
+(W threads)(S) When using threaded Perl, a thread (not necessarily the main
+thread) exited while there were still other threads running.
+Usually it's a good idea to first collect the return values of the
+created threads by joining them, and only then exit from the main
+thread. See L<threads>.
+
+=item Attempt to access disallowed key '%s' in a restricted hash
+
+(F) The failing code has attempted to get or set a key which is not in
+the current set of allowed keys of a restricted hash.
+
+=item Attempt to bless into a reference
+
+(F) The CLASSNAME argument to the bless() operator is expected to be
+the name of the package to bless the resulting object into. You've
+supplied instead a reference to something: perhaps you wrote
+
+ bless $self, $proto;
+
+when you intended
+
+ bless $self, ref($proto) || $proto;
+
+If you actually want to bless into the stringified version
+of the reference supplied, you need to stringify it yourself, for
+example by:
+
+ bless $self, "$proto";
+
+=item Attempt to delete disallowed key '%s' from a restricted hash
+
+(F) The failing code attempted to delete from a restricted hash a key
+which is not in its key set.
+
+=item Attempt to delete readonly key '%s' from a restricted hash
+
+(F) The failing code attempted to delete a key whose value has been
+declared readonly from a restricted hash.
+
+=item Attempt to free non-arena SV: 0x%lx
+
+(P internal) All SV objects are supposed to be allocated from arenas
+that will be garbage collected on exit. An SV was discovered to be
+outside any of those arenas.
+
+=item Attempt to free nonexistent shared string
+
+(P internal) Perl maintains a reference counted internal table of
+strings to optimize the storage and access of hash keys and other
+strings. This indicates someone tried to decrement the reference count
+of a string that can no longer be found in the table.
+
+=item Attempt to free temp prematurely
+
+(W debugging) Mortalized values are supposed to be freed by the
+free_tmps() routine. This indicates that something else is freeing the
+SV before the free_tmps() routine gets a chance, which means that the
+free_tmps() routine will be freeing an unreferenced scalar when it does
+try to free it.
+
+=item Attempt to free unreferenced glob pointers
+
+(P internal) The reference counts got screwed up on symbol aliases.
+
+=item Attempt to free unreferenced scalar
+
+(W internal) Perl went to decrement the reference count of a scalar to
+see if it would go to 0, and discovered that it had already gone to 0
+earlier, and should have been freed, and in fact, probably was freed.
+This could indicate that SvREFCNT_dec() was called too many times, or
+that SvREFCNT_inc() was called too few times, or that the SV was
+mortalized when it shouldn't have been, or that memory has been
+corrupted.
+
+=item Attempt to join self
+
+(F) You tried to join a thread from within itself, which is an
+impossible task. You may be joining the wrong thread, or you may need
+to move the join() to some other thread.
+
+=item Attempt to pack pointer to temporary value
+
+(W pack) You tried to pass a temporary value (like the result of a
+function, or a computed expression) to the "p" pack() template. This
+means the result contains a pointer to a location that could become
+invalid anytime, even before the end of the current statement. Use
+literals or global values as arguments to the "p" pack() template to
+avoid this warning.
+
+=item Attempt to reload %s aborted.
+
+(F) You tried to load a file with C<use> or C<require> that failed to
+compile once already. Perl will not try to compile this file again
+unless you delete its entry from %INC. See L<perlfunc/require> and
+L<perlvar/%INC>.
+
+=item Attempt to set length of freed array
+
+(W) You tried to set the length of an array which has been freed. You
+can do this by storing a reference to the scalar representing the last index
+of an array and later assigning through that reference. For example
+
+ $r = do {my @a; \$#a};
+ $$r = 503
+
+=item Attempt to use reference as lvalue in substr
+
+(W substr) You supplied a reference as the first argument to substr()
+used as an lvalue, which is pretty strange. Perhaps you forgot to
+dereference it first. See L<perlfunc/substr>.
+
+=item Bad arg length for %s, is %d, should be %s
+
+(F) You passed a buffer of the wrong size to one of msgctl(), semctl()
+or shmctl(). In C parlance, the correct sizes are, respectively,
+S<sizeof(struct msqid_ds *)>, S<sizeof(struct semid_ds *)>, and
+S<sizeof(struct shmid_ds *)>.
+
+=item Bad evalled substitution pattern
+
+(F) You've used the C</e> switch to evaluate the replacement for a
+substitution, but perl found a syntax error in the code to evaluate,
+most likely an unexpected right brace '}'.
+
+=item Bad filehandle: %s
+
+(F) A symbol was passed to something wanting a filehandle, but the
+symbol has no filehandle associated with it. Perhaps you didn't do an
+open(), or did it in another package.
+
+=item Bad free() ignored
+
+(S malloc) An internal routine called free() on something that had never
+been malloc()ed in the first place. Mandatory, but can be disabled by
+setting environment variable C<PERL_BADFREE> to 0.
+
+This message can be seen quite often with DB_File on systems with "hard"
+dynamic linking, like C<AIX> and C<OS/2>. It is a bug of C<Berkeley DB>
+which is left unnoticed if C<DB> uses I<forgiving> system malloc().
+
+=item Bad hash
+
+(P) One of the internal hash routines was passed a null HV pointer.
+
+=item Badly placed ()'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 Bad name after %s::
+
+(F) You started to name a symbol by using a package prefix, and then
+didn't finish the symbol. In particular, you can't interpolate outside
+of quotes, so
+
+ $var = 'myvar';
+ $sym = mypack::$var;
+
+is not the same as
+
+ $var = 'myvar';
+ $sym = "mypack::$var";
+
+=item Bad realloc() ignored
+
+(S malloc) An internal routine called realloc() on something that had
+never been malloc()ed in the first place. Mandatory, but can be disabled
+by setting environment variable C<PERL_BADFREE> to 1.
+
+=item Bad symbol for array
+
+(P) An internal request asked to add an array entry to something that
+wasn't a symbol table entry.
+
+=item Bad symbol for dirhandle
+
+(P) An internal request asked to add a dirhandle entry to something
+that wasn't a symbol table entry.
+
+
+=item Bad symbol for filehandle
+
+(P) An internal request asked to add a filehandle entry to something
+that wasn't a symbol table entry.
+
+=item Bad symbol for hash
+
+(P) An internal request asked to add a hash entry to something that
+wasn't a symbol table entry.
+
+=item Bareword found in conditional
+
+(W bareword) The compiler found a bareword where it expected a
+conditional, which often indicates that an || or && was parsed as part
+of the last argument of the previous construct, for example:
+
+ open FOO || die;
+
+It may also indicate a misspelled constant that has been interpreted as
+a bareword:
+
+ use constant TYPO => 1;
+ if (TYOP) { print "foo" }
+
+The C<strict> pragma is useful in avoiding such errors.
+
+=item Bareword "%s" not allowed while "strict subs" in use
+
+(F) With "strict subs" in use, a bareword is only allowed as a
+subroutine identifier, in curly brackets or to the left of the "=>"
+symbol. Perhaps you need to predeclare a subroutine?
+
+=item Bareword "%s" refers to nonexistent package
+
+(W bareword) You used a qualified bareword of the form C<Foo::>, but the
+compiler saw no other uses of that namespace before that point. Perhaps
+you need to predeclare a package?
+
+=item BEGIN failed--compilation aborted
+
+(F) An untrapped exception was raised while executing a BEGIN
+subroutine. Compilation stops immediately and the interpreter is
+exited.
+
+=item BEGIN not safe after errors--compilation aborted
+
+(F) Perl found a C<BEGIN {}> subroutine (or a C<use> directive, which
+implies a C<BEGIN {}>) after one or more compilation errors had already
+occurred. Since the intended environment for the C<BEGIN {}> could not
+be guaranteed (due to the errors), and since subsequent code likely
+depends on its correct operation, Perl just gave up.
+
+=item \1 better written as $1
+
+(W syntax) Outside of patterns, backreferences live on as variables.
+The use of backslashes is grandfathered on the right-hand side of a
+substitution, but stylistically it's better to use the variable form
+because other Perl programmers will expect it, and it works better if
+there are more than 9 backreferences.
+
+=item Binary number > 0b11111111111111111111111111111111 non-portable
+
+(W portable) The binary number you specified is larger than 2**32-1
+(4294967295) and therefore non-portable between systems. See
+L<perlport> for more on portability concerns.
+
+=item bind() on closed socket %s
+
+(W closed) You tried to do a bind on a closed socket. Did you forget to
+check the return value of your socket() call? See L<perlfunc/bind>.
+
+=item binmode() on closed filehandle %s
+
+(W unopened) You tried binmode() on a filehandle that was never opened.
+Check you control flow and number of arguments.
+
+=item Bit vector size > 32 non-portable
+
+(W portable) Using bit vector sizes larger than 32 is non-portable.
+
+=item Bizarre copy of %s in %s
+
+(P) Perl detected an attempt to copy an internal value that is not
+copyable.
+
+=item Buffer overflow in prime_env_iter: %s
+
+(W internal) A warning peculiar to VMS. While Perl was preparing to
+iterate over %ENV, it encountered a logical name or symbol definition
+which was too long, so it was truncated to the string shown.
+
+=item Callback called exit
+
+(F) A subroutine invoked from an external package via call_sv()
+exited by calling exit.
+
+=item %s() called too early to check prototype
+
+(W prototype) You've called a function that has a prototype before the
+parser saw a definition or declaration for it, and Perl could not check
+that the call conforms to the prototype. You need to either add an
+early prototype declaration for the subroutine in question, or move the
+subroutine definition ahead of the call to get proper prototype
+checking. Alternatively, if you are certain that you're calling the
+function correctly, you may put an ampersand before the name to avoid
+the warning. See L<perlsub>.
+
+=item Cannot compress integer in pack
+
+(F) An argument to pack("w",...) was too large to compress. The BER
+compressed integer format can only be used with positive integers, and you
+attempted to compress Infinity or a very large number (> 1e308).
+See L<perlfunc/pack>.
+
+=item Cannot compress negative numbers in pack
+
+(F) An argument to pack("w",...) was negative. The BER compressed integer
+format can only be used with positive integers. See L<perlfunc/pack>.
+
+=item Cannot convert a reference to %s to typeglob
+
+(F) You manipulated Perl's symbol table directly, stored a reference in it,
+then tried to access that symbol via conventional Perl syntax. The access
+triggers Perl to autovivify that typeglob, but it there is no legal conversion
+from that type of reference to a typeglob.
+
+=item Cannot copy to %s in %s
+
+(P) Perl detected an attempt to copy a value to an internal type that cannot
+be directly assigned not.
+
+=item Can only compress unsigned integers in pack
+
+(F) An argument to pack("w",...) was not an integer. The BER compressed
+integer format can only be used with positive integers, and you attempted
+to compress something else. See L<perlfunc/pack>.
+
+=item Can't bless non-reference value
+
+(F) Only hard references may be blessed. This is how Perl "enforces"
+encapsulation of objects. See L<perlobj>.
+
+=item Can't "break" in a loop topicalizer
+
+(F) You called C<break>, but you're in a C<foreach> block rather than
+a C<given> block. You probably meant to use C<next> or C<last>.
+
+=item Can't "break" outside a given block
+
+(F) You called C<break>, but you're not inside a C<given> block.
+
+=item Can't call method "%s" in empty package "%s"
+
+(F) You called a method correctly, and it correctly indicated a package
+functioning as a class, but that package doesn't have ANYTHING defined
+in it, let alone methods. See L<perlobj>.
+
+=item Can't call method "%s" on an undefined value
+
+(F) You used the syntax of a method call, but the slot filled by the
+object reference or package name contains an undefined value. Something
+like this will reproduce the error:
+
+ $BADREF = undef;
+ process $BADREF 1,2,3;
+ $BADREF->process(1,2,3);
+
+=item Can't call method "%s" on unblessed reference
+
+(F) A method call must know in what package it's supposed to run. It
+ordinarily finds this out from the object reference you supply, but you
+didn't supply an object reference in this case. A reference isn't an
+object reference until it has been blessed. See L<perlobj>.
+
+=item Can't call method "%s" without a package or object reference
+
+(F) You used the syntax of a method call, but the slot filled by the
+object reference or package name contains an expression that returns a
+defined value which is neither an object reference nor a package name.
+Something like this will reproduce the error:
+
+ $BADREF = 42;
+ process $BADREF 1,2,3;
+ $BADREF->process(1,2,3);
+
+=item Can't chdir to %s
+
+(F) You called C<perl -x/foo/bar>, but C</foo/bar> is not a directory
+that you can chdir to, possibly because it doesn't exist.
+
+=item Can't check filesystem of script "%s" for nosuid
+
+(P) For some reason you can't check the filesystem of the script for
+nosuid.
+
+=item Can't coerce array into hash
+
+(F) You used an array where a hash was expected, but the array has no
+information on how to map from keys to array indices. You can do that
+only with arrays that have a hash reference at index 0.
+
+=item Can't coerce %s to integer in %s
+
+(F) Certain types of SVs, in particular real symbol table entries
+(typeglobs), can't be forced to stop being what they are. So you can't
+say things like:
+
+ *foo += 1;
+
+You CAN say
+
+ $foo = *foo;
+ $foo += 1;
+
+but then $foo no longer contains a glob.
+
+=item Can't coerce %s to number in %s
+
+(F) Certain types of SVs, in particular real symbol table entries
+(typeglobs), can't be forced to stop being what they are.
+
+=item Can't coerce %s to string in %s
+
+(F) Certain types of SVs, in particular real symbol table entries
+(typeglobs), can't be forced to stop being what they are.
+
+=item Can't "continue" outside a when block
+
+(F) You called C<continue>, but you're not inside a C<when>
+or C<default> block.
+
+=item Can't create pipe mailbox
+
+(P) An error peculiar to VMS. The process is suffering from exhausted
+quotas or other plumbing problems.
+
+=item Can't declare class for non-scalar %s in "%s"
+
+(F) Currently, only scalar variables can be declared with a specific
+class qualifier in a "my", "our" or "state" declaration. The semantics may be
+extended for other types of variables in future.
+
+=item Can't declare %s in "%s"
+
+(F) Only scalar, array, and hash variables may be declared as "my", "our" or
+"state" variables. They must have ordinary identifiers as names.
+
+=item Can't do inplace edit: %s is not a regular file
+
+(S inplace) You tried to use the B<-i> switch on a special file, such as
+a file in /dev, or a FIFO. The file was ignored.
+
+=item Can't do inplace edit on %s: %s
+
+(S inplace) The creation of the new file failed for the indicated
+reason.
+
+=item Can't do inplace edit without backup
+
+(F) You're on a system such as MS-DOS that gets confused if you try
+reading from a deleted (but still opened) file. You have to say
+C<-i.bak>, or some such.
+
+=item Can't do inplace edit: %s would not be unique
+
+(S inplace) Your filesystem does not support filenames longer than 14
+characters and Perl was unable to create a unique filename during
+inplace editing with the B<-i> switch. The file was ignored.
+
+=item Can't do {n,m} with n > m in regex; marked by <-- HERE in m/%s/
+
+(F) Minima must be less than or equal to maxima. If you really want your
+regexp to match something 0 times, just put {0}. The <-- HERE shows in the
+regular expression about where the problem was discovered. See L<perlre>.
+
+=item Can't do setegid!
+
+(P) The setegid() call failed for some reason in the setuid emulator of
+suidperl.
+
+=item Can't do seteuid!
+
+(P) The setuid emulator of suidperl failed for some reason.
+
+=item Can't do setuid
+
+(F) This typically means that ordinary perl tried to exec suidperl to do
+setuid emulation, but couldn't exec it. It looks for a name of the form
+sperl5.000 in the same directory that the perl executable resides under
+the name perl5.000, typically /usr/local/bin on Unix machines. If the
+file is there, check the execute permissions. If it isn't, ask your
+sysadmin why he and/or she removed it.
+
+=item Can't do waitpid with flags
+
+(F) This machine doesn't have either waitpid() or wait4(), so only
+waitpid() without flags is emulated.
+
+=item Can't emulate -%s on #! line
+
+(F) The #! line specifies a switch that doesn't make sense at this
+point. For example, it'd be kind of silly to put a B<-x> on the #!
+line.
+
+=item Can't %s %s-endian %ss on this platform
+
+(F) Your platform's byte-order is neither big-endian nor little-endian,
+or it has a very strange pointer size. Packing and unpacking big- or
+little-endian floating point values and pointers may not be possible.
+See L<perlfunc/pack>.
+
+=item Can't exec "%s": %s
+
+(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
+architecture, or the #! line in a script points to an interpreter that
+can't be run for similar reasons. (Or maybe your system doesn't support
+#! at all.)
+
+=item Can't exec %s
+
+(F) Perl was trying to execute the indicated program for you because
+that's what the #! line said. If that's not what you wanted, you may
+need to mention "perl" on the #! line somewhere.
+
+=item Can't execute %s
+
+(F) You used the B<-S> switch, but the copies of the script to execute
+found in the PATH did not have correct permissions.
+
+=item Can't find an opnumber for "%s"
+
+(F) A string of a form C<CORE::word> was given to prototype(), but there
+is no builtin with the name C<word>.
+
+=item Can't find %s character property "%s"
+
+(F) You used C<\p{}> or C<\P{}> but the character property by that name
+could not be found. Maybe you misspelled the name of the property
+(remember that the names of character properties consist only of
+alphanumeric characters), or maybe you forgot the C<Is> or C<In> prefix?
+
+=item Can't find label %s
+
+(F) You said to goto a label that isn't mentioned anywhere that it's
+possible for us to go to. See L<perlfunc/goto>.
+
+=item Can't find %s on PATH
+
+(F) You used the B<-S> switch, but the script to execute could not be
+found in the PATH.
+
+=item Can't find %s on PATH, '.' not in PATH
+
+(F) You used the B<-S> switch, but the script to execute could not be
+found in the PATH, or at least not with the correct permissions. The
+script exists in the current directory, but PATH prohibits running it.
+
+=item Can't find string terminator %s anywhere before EOF
+
+(F) Perl strings can stretch over multiple lines. This message means
+that the closing delimiter was omitted. Because bracketed quotes count
+nesting levels, the following is missing its final parenthesis:
+
+ print q(The character '(' starts a side comment.);
+
+If you're getting this error from a here-document, you may have included
+unseen whitespace before or after your closing tag. A good programmer's
+editor will have a way to help you find these characters.
+
+=item Can't find Unicode property definition "%s"
+
+(F) You may have tried to use C<\p> which means a Unicode property (for
+example C<\p{Lu}> is all uppercase letters). If you did mean to use a
+Unicode property, see L<perlunicode> for the list of known properties.
+If you didn't mean to use a Unicode property, escape the C<\p>, either
+by C<\\p> (just the C<\p>) or by C<\Q\p> (the rest of the string, until
+possible C<\E>).
+
+=item Can't fork
+
+(F) A fatal error occurred while trying to fork while opening a
+pipeline.
+
+=item Can't get filespec - stale stat buffer?
+
+(S) A warning peculiar to VMS. This arises because of the difference
+between access checks under VMS and under the Unix model Perl assumes.
+Under VMS, access checks are done by filename, rather than by bits in
+the stat buffer, so that ACLs and other protections can be taken into
+account. Unfortunately, Perl assumes that the stat buffer contains all
+the necessary information, and passes it, instead of the filespec, to
+the access checking routine. It will try to retrieve the filespec using
+the device name and FID present in the stat buffer, but this works only
+if you haven't made a subsequent call to the CRTL stat() routine,
+because the device name is overwritten with each call. If this warning
+appears, the name lookup failed, and the access checking routine gave up
+and returned FALSE, just to be conservative. (Note: The access checking
+routine knows about the Perl C<stat> operator and file tests, so you
+shouldn't ever see this warning in response to a Perl command; it arises
+only if some internal code takes stat buffers lightly.)
+
+=item Can't get pipe mailbox device name
+
+(P) An error peculiar to VMS. After creating a mailbox to act as a
+pipe, Perl can't retrieve its name for later use.
+
+=item Can't get SYSGEN parameter value for MAXBUF
+
+(P) An error peculiar to VMS. Perl asked $GETSYI how big you want your
+mailbox buffers to be, and didn't get an answer.
+
+=item Can't "goto" into the middle of a foreach loop
+
+(F) A "goto" statement was executed to jump into the middle of a foreach
+loop. You can't get there from here. See L<perlfunc/goto>.
+
+=item Can't "goto" out of a pseudo block
+
+(F) A "goto" statement was executed to jump out of what might look like
+a block, except that it isn't a proper block. This usually occurs if
+you tried to jump out of a sort() block or subroutine, which is a no-no.
+See L<perlfunc/goto>.
+
+=item Can't goto subroutine from a sort sub (or similar callback)
+
+(F) The "goto subroutine" call can't be used to jump out of the
+comparison sub for a sort(), or from a similar callback (such
+as the reduce() function in List::Util).
+
+=item Can't goto subroutine from an eval-%s
+
+(F) The "goto subroutine" call can't be used to jump out of an eval
+"string" or block.
+
+=item Can't goto subroutine outside a subroutine
+
+(F) The deeply magical "goto subroutine" call can only replace one
+subroutine call for another. It can't manufacture one out of whole
+cloth. In general you should be calling it out of only an AUTOLOAD
+routine anyway. See L<perlfunc/goto>.
+
+=item Can't ignore signal CHLD, forcing to default
+
+(W signal) Perl has detected that it is being run with the SIGCHLD
+signal (sometimes known as SIGCLD) disabled. Since disabling this
+signal will interfere with proper determination of exit status of child
+processes, Perl has reset the signal to its default value. This
+situation typically indicates that the parent program under which Perl
+may be running (e.g. cron) is being very careless.
+
+=item Can't "last" outside a loop block
+
+(F) A "last" statement was executed to break out of the current block,
+except that there's this itty bitty problem called there isn't a current
+block. Note that an "if" or "else" block doesn't count as a "loopish"
+block, as doesn't a block given to sort(), map() or grep(). You can
+usually double the curlies to get the same effect though, because the
+inner curlies will be considered a block that loops once. See
+L<perlfunc/last>.
+
+=item Can't linearize anonymous symbol table
+
+(F) Perl tried to calculate the method resolution order (MRO) of a
+package, but failed because the package stash has no name.
+
+=item Can't load '%s' for module %s
+
+(F) The module you tried to load failed to load a dynamic extension. This
+may either mean that you upgraded your version of perl to one that is
+incompatible with your old dynamic extensions (which is known to happen
+between major versions of perl), or (more likely) that your dynamic
+extension was built against an older version of the library that is
+installed on your system. You may need to rebuild your old dynamic
+extensions.
+
+=item Can't localize lexical variable %s
+
+(F) You used local on a variable name that was previously declared as a
+lexical variable using "my" or "state". This is not allowed. If you want to
+localize a package variable of the same name, qualify it with the
+package name.
+
+=item Can't localize through a reference
+
+(F) You said something like C<local $$ref>, which Perl can't currently
+handle, because when it goes to restore the old value of whatever $ref
+pointed to after the scope of the local() is finished, it can't be sure
+that $ref will still be a reference.
+
+=item Can't locate %s
+
+(F) You said to C<do> (or C<require>, or C<use>) a file that couldn't be
+found. Perl looks for the file in all the locations mentioned in @INC,
+unless the file name included the full path to the file. Perhaps you
+need to set the PERL5LIB or PERL5OPT environment variable to say where
+the extra library is, or maybe the script needs to add the library name
+to @INC. Or maybe you just misspelled the name of the file. See
+L<perlfunc/require> and L<lib>.
+
+=item Can't locate auto/%s.al in @INC
+
+(F) A function (or method) was called in a package which allows
+autoload, but there is no function to autoload. Most probable causes
+are a misprint in a function/method name or a failure to C<AutoSplit>
+the file, say, by doing C<make install>.
+
+=item Can't locate loadable object for module %s in @INC
+
+(F) The module you loaded is trying to load an external library, like
+for example, C<foo.so> or C<bar.dll>, but the L<DynaLoader> module was
+unable to locate this library. See L<DynaLoader>.
+
+=item Can't locate object method "%s" via package "%s"
+
+(F) You called a method correctly, and it correctly indicated a package
+functioning as a class, but that package doesn't define that particular
+method, nor does any of its base classes. See L<perlobj>.
+
+=item Can't locate package %s for @%s::ISA
+
+(W syntax) The @ISA array contained the name of another package that
+doesn't seem to exist.
+
+=item Can't locate PerlIO%s
+
+(F) You tried to use in open() a PerlIO layer that does not exist,
+e.g. open(FH, ">:nosuchlayer", "somefile").
+
+=item Can't make list assignment to \%ENV on this system
+
+(F) List assignment to %ENV is not supported on some systems, notably
+VMS.
+
+=item Can't modify %s in %s
+
+(F) You aren't allowed to assign to the item indicated, or otherwise try
+to change it, such as with an auto-increment.
+
+=item Can't modify nonexistent substring
+
+(P) The internal routine that does assignment to a substr() was handed
+a NULL.
+
+=item Can't modify non-lvalue subroutine call
+
+(F) Subroutines meant to be used in lvalue context should be declared as
+such, see L<perlsub/"Lvalue subroutines">.
+
+=item Can't msgrcv to read-only var
+
+(F) The target of a msgrcv must be modifiable to be used as a receive
+buffer.
+
+=item Can't "next" outside a loop block
+
+(F) A "next" statement was executed to reiterate the current block, but
+there isn't a current block. Note that an "if" or "else" block doesn't
+count as a "loopish" block, as doesn't a block given to sort(), map() or
+grep(). You can usually double the curlies to get the same effect
+though, because the inner curlies will be considered a block that loops
+once. See L<perlfunc/next>.
+
+=item Can't open %s: %s
+
+(S inplace) The implicit opening of a file through use of the C<< <> >>
+filehandle, either implicitly under the C<-n> or C<-p> command-line
+switches, or explicitly, failed for the indicated reason. Usually this
+is because you don't have read permission for a file which you named on
+the command line.
+
+=item Can't open a reference
+
+(W io) You tried to open a scalar reference for reading or writing,
+using the 3-arg open() syntax :
+
+ open FH, '>', $ref;
+
+but your version of perl is compiled without perlio, and this form of
+open is not supported.
+
+=item Can't open bidirectional pipe
+
+(W pipe) You tried to say C<open(CMD, "|cmd|")>, which is not supported.
+You can try any of several modules in the Perl library to do this, such
+as IPC::Open2. Alternately, direct the pipe's output to a file using
+">", and then read it in under a different file handle.
+
+=item Can't open error file %s as stderr
+
+(F) An error peculiar to VMS. Perl does its own command line
+redirection, and couldn't open the file specified after '2>' or '2>>' on
+the command line for writing.
+
+=item Can't open input file %s as stdin
+
+(F) An error peculiar to VMS. Perl does its own command line
+redirection, and couldn't open the file specified after '<' on the
+command line for reading.
+
+=item Can't open output file %s as stdout
+
+(F) An error peculiar to VMS. Perl does its own command line
+redirection, and couldn't open the file specified after '>' or '>>' on
+the command line for writing.
+
+=item Can't open output pipe (name: %s)
+
+(P) An error peculiar to VMS. Perl does its own command line
+redirection, and couldn't open the pipe into which to send data destined
+for stdout.
+
+=item Can't open perl script%s
+
+(F) The script you specified can't be opened for the indicated reason.
+
+If you're debugging a script that uses #!, and normally relies on the
+shell's $PATH search, the -S option causes perl to do that search, so
+you don't have to type the path or C<`which $scriptname`>.
+
+=item Can't read CRTL environ
+
+(S) A warning peculiar to VMS. Perl tried to read an element of %ENV
+from the CRTL's internal environment array and discovered the array was
+missing. You need to figure out where your CRTL misplaced its environ
+or define F<PERL_ENV_TABLES> (see L<perlvms>) so that environ is not
+searched.
+
+=item Can't "redo" outside a loop block
+
+(F) A "redo" statement was executed to restart the current block, but
+there isn't a current block. Note that an "if" or "else" block doesn't
+count as a "loopish" block, as doesn't a block given to sort(), map()
+or grep(). You can usually double the curlies to get the same effect
+though, because the inner curlies will be considered a block that
+loops once. See L<perlfunc/redo>.
+
+=item Can't remove %s: %s, skipping file
+
+(S inplace) You requested an inplace edit without creating a backup
+file. Perl was unable to remove the original file to replace it with
+the modified file. The file was left unmodified.
+
+=item Can't rename %s to %s: %s, skipping file
+
+(S inplace) The rename done by the B<-i> switch failed for some reason,
+probably because you don't have write permission to the directory.
+
+=item Can't reopen input pipe (name: %s) in binary mode
+
+(P) An error peculiar to VMS. Perl thought stdin was a pipe, and tried
+to reopen it to accept binary data. Alas, it failed.
+
+=item Can't resolve method `%s' overloading `%s' in package `%s'
+
+(F|P) Error resolving overloading specified by a method name (as opposed
+to a subroutine reference): no such method callable via the package. If
+method name is C<???>, this is an internal error.
+
+=item Can't reswap uid and euid
+
+(P) The setreuid() call failed for some reason in the setuid emulator of
+suidperl.
+
+=item Can't return %s from lvalue subroutine
+
+(F) Perl detected an attempt to return illegal lvalues (such as
+temporary or readonly values) from a subroutine used as an lvalue. This
+is not allowed.
+
+=item Can't return outside a subroutine
+
+(F) The return statement was executed in mainline code, that is, where
+there was no subroutine call to return out of. See L<perlsub>.
+
+=item Can't return %s to lvalue scalar context
+
+(F) You tried to return a complete array or hash from an lvalue subroutine,
+but you called the subroutine in a way that made Perl think you meant
+to return only one value. You probably meant to write parentheses around
+the call to the subroutine, which tell Perl that the call should be in
+list context.
+
+=item Can't stat script "%s"
+
+(P) For some reason you can't fstat() the script even though you have it
+open already. Bizarre.
+
+=item Can't swap uid and euid
+
+(P) The setreuid() call failed for some reason in the setuid emulator of
+suidperl.
+
+=item Can't take log of %g
+
+(F) For ordinary real numbers, you can't take the logarithm of a
+negative number or zero. There's a Math::Complex package that comes
+standard with Perl, though, if you really want to do that for the
+negative numbers.
+
+=item Can't take sqrt of %g
+
+(F) For ordinary real numbers, you can't take the square root of a
+negative number. There's a Math::Complex package that comes standard
+with Perl, though, if you really want to do that.
+
+=item Can't undef active subroutine
+
+(F) You can't undefine a routine that's currently running. You can,
+however, redefine it while it's running, and you can even undef the
+redefined subroutine while the old routine is running. Go figure.
+
+=item Can't unshift
+
+(F) You tried to unshift an "unreal" array that can't be unshifted, such
+as the main Perl stack.
+
+=item Can't upgrade %s (%d) to %d
+
+(P) The internal sv_upgrade routine adds "members" to an SV, making it
+into a more specialized kind of SV. The top several SV types are so
+specialized, however, that they cannot be interconverted. This message
+indicates that such a conversion was attempted.
+
+=item Can't use anonymous symbol table for method lookup
+
+(F) The internal routine that does method lookup was handed a symbol
+table that doesn't have a name. Symbol tables can become anonymous
+for example by undefining stashes: C<undef %Some::Package::>.
+
+=item Can't use an undefined value as %s reference
+
+(F) A value used as either a hard reference or a symbolic reference must
+be a defined value. This helps to delurk some insidious errors.
+
+=item Can't use bareword ("%s") as %s ref while "strict refs" in use
+
+(F) Only hard references are allowed by "strict refs". Symbolic
+references are disallowed. See L<perlref>.
+
+=item Can't use %! because Errno.pm is not available
+
+(F) The first time the %! hash is used, perl automatically loads the
+Errno.pm module. The Errno module is expected to tie the %! hash to
+provide symbolic names for C<$!> errno values.
+
+=item Can't use both '<' and '>' after type '%c' in %s
+
+(F) A type cannot be forced to have both big-endian and little-endian
+byte-order at the same time, so this combination of modifiers is not
+allowed. See L<perlfunc/pack>.
+
+=item Can't use %s for loop variable
+
+(F) Only a simple scalar variable may be used as a loop variable on a
+foreach.
+
+=item Can't use global %s in "%s"
+
+(F) You tried to declare a magical variable as a lexical variable. This
+is not allowed, because the magic can be tied to only one location
+(namely the global variable) and it would be incredibly confusing to
+have variables in your program that looked like magical variables but
+weren't.
+
+=item Can't use '%c' in a group with different byte-order in %s
+
+(F) You attempted to force a different byte-order on a type
+that is already inside a group with a byte-order modifier.
+For example you cannot force little-endianness on a type that
+is inside a big-endian group.
+
+=item Can't use "my %s" in sort comparison
+
+(F) The global variables $a and $b are reserved for sort comparisons.
+You mentioned $a or $b in the same line as the <=> or cmp operator,
+and the variable had earlier been declared as a lexical variable.
+Either qualify the sort variable with the package name, or rename the
+lexical variable.
+
+=item Can't use %s ref as %s ref
+
+(F) You've mixed up your reference types. You have to dereference a
+reference of the type needed. You can use the ref() function to
+test the type of the reference, if need be.
+
+=item Can't use string ("%s") as %s ref while "strict refs" in use
+
+(F) Only hard references are allowed by "strict refs". Symbolic
+references are disallowed. See L<perlref>.
+
+=item Can't use subscript on %s
+
+(F) The compiler tried to interpret a bracketed expression as a
+subscript. But to the left of the brackets was an expression that
+didn't look like a hash or array reference, or anything else subscriptable.
+
+=item Can't use \%c to mean $%c in expression
+
+(W syntax) In an ordinary expression, backslash is a unary operator that
+creates a reference to its argument. The use of backslash to indicate a
+backreference to a matched substring is valid only as part of a regular
+expression pattern. Trying to do this in ordinary Perl code produces a
+value that prints out looking like SCALAR(0xdecaf). Use the $1 form
+instead.
+
+=item Can't use "when" outside a topicalizer
+
+(F) You have used a when() block that is neither inside a C<foreach>
+loop nor a C<given> block. (Note that this error is issued on exit
+from the C<when> block, so you won't get the error if the match fails,
+or if you use an explicit C<continue>.)
+
+=item Can't weaken a nonreference
+
+(F) You attempted to weaken something that was not a reference. Only
+references can be weakened.
+
+=item Can't x= to read-only value
+
+(F) You tried to repeat a constant value (often the undefined value)
+with an assignment operator, which implies modifying the value itself.
+Perhaps you need to copy the value to a temporary, and repeat that.
+
+=item Character in 'C' format wrapped in pack
+
+(W pack) You said
+
+ pack("C", $x)
+
+where $x is either less than 0 or more than 255; the C<"C"> format is
+only for encoding native operating system characters (ASCII, EBCDIC,
+and so on) and not for Unicode characters, so Perl behaved as if you meant
+
+ pack("C", $x & 255)
+
+If you actually want to pack Unicode codepoints, use the C<"U"> format
+instead.
+
+=item Character in 'W' format wrapped in pack
+
+(W pack) You said
+
+ pack("U0W", $x)
+
+where $x is either less than 0 or more than 255. However, C<U0>-mode expects
+all values to fall in the interval [0, 255], so Perl behaved as if you
+meant:
+
+ pack("U0W", $x & 255)
+
+=item Character in 'c' format wrapped in pack
+
+(W pack) You said
+
+ pack("c", $x)
+
+where $x is either less than -128 or more than 127; the C<"c"> format
+is only for encoding native operating system characters (ASCII, EBCDIC,
+and so on) and not for Unicode characters, so Perl behaved as if you meant
+
+ pack("c", $x & 255);
+
+If you actually want to pack Unicode codepoints, use the C<"U"> format
+instead.
+
+=item Character in '%c' format wrapped in unpack
+
+(W unpack) You tried something like
+
+ unpack("H", "\x{2a1}")
+
+where the format expects to process a byte (a character with a value
+below 256), but a higher value was provided instead. Perl uses the value
+modulus 256 instead, as if you had provided:
+
+ unpack("H", "\x{a1}")
+
+=item Character(s) in '%c' format wrapped in pack
+
+(W pack) You tried something like
+
+ pack("u", "\x{1f3}b")
+
+where the format expects to process a sequence of bytes (character with a
+value below 256), but some of the characters had a higher value. Perl
+uses the character values modulus 256 instead, as if you had provided:
+
+ pack("u", "\x{f3}b")
+
+=item Character(s) in '%c' format wrapped in unpack
+
+(W unpack) You tried something like
+
+ unpack("s", "\x{1f3}b")
+
+where the format expects to process a sequence of bytes (character with a
+value below 256), but some of the characters had a higher value. Perl
+uses the character values modulus 256 instead, as if you had provided:
+
+ unpack("s", "\x{f3}b")
+
+=item close() on unopened filehandle %s
+
+(W unopened) You tried to close a filehandle that was never opened.
+
+=item closedir() attempted on invalid dirhandle %s
+
+(W io) The dirhandle you tried to close is either closed or not really
+a dirhandle. Check your control flow.
+
+=item Code missing after '/'
+
+(F) You had a (sub-)template that ends with a '/'. There must be another
+template code following the slash. See L<perlfunc/pack>.
+
+=item %s: Command not found
+
+(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 Compilation failed in require
+
+(F) Perl could not compile a file specified in a C<require> statement.
+Perl uses this generic message when none of the errors that it
+encountered were severe enough to halt compilation immediately.
+
+=item Complex regular subexpression recursion limit (%d) exceeded
+
+(W regexp) The regular expression engine uses recursion in complex
+situations where back-tracking is required. Recursion depth is limited
+to 32766, or perhaps less in architectures where the stack cannot grow
+arbitrarily. ("Simple" and "medium" situations are handled without
+recursion and are not subject to a limit.) Try shortening the string
+under examination; looping in Perl code (e.g. with C<while>) rather than
+in the regular expression engine; or rewriting the regular expression so
+that it is simpler or backtracks less. (See L<perlfaq2> for information
+on I<Mastering Regular Expressions>.)
+
+=item cond_broadcast() called on unlocked variable
+
+(W threads) Within a thread-enabled program, you tried to call
+cond_broadcast() on a variable which wasn't locked. The cond_broadcast()
+function is used to wake up another thread that is waiting in a
+cond_wait(). To ensure that the signal isn't sent before the other thread
+has a chance to enter the wait, it is usual for the signaling thread to
+first wait for a lock on variable. This lock attempt will only succeed
+after the other thread has entered cond_wait() and thus relinquished the
+lock.
+
+=item cond_signal() called on unlocked variable
+
+(W threads) Within a thread-enabled program, you tried to call
+cond_signal() on a variable which wasn't locked. The cond_signal()
+function is used to wake up another thread that is waiting in a
+cond_wait(). To ensure that the signal isn't sent before the other thread
+has a chance to enter the wait, it is usual for the signaling thread to
+first wait for a lock on variable. This lock attempt will only succeed
+after the other thread has entered cond_wait() and thus relinquished the
+lock.
+
+=item connect() on closed socket %s
+
+(W closed) You tried to do a connect on a closed socket. Did you forget
+to check the return value of your socket() call? See
+L<perlfunc/connect>.
+
+=item Constant(%s)%s: %s
+
+(F) The parser found inconsistencies either while attempting to define
+an overloaded constant, or when trying to find the character name
+specified in the C<\N{...}> escape. Perhaps you forgot to load the
+corresponding C<overload> or C<charnames> pragma? See L<charnames> and
+L<overload>.
+
+=item Constant(%s)%s: %s in regex; marked by <-- HERE in m/%s/
+
+(F) The parser found inconsistencies while attempting to find
+the character name specified in the C<\N{...}> escape. Perhaps you
+forgot to load the corresponding C<charnames> pragma?
+See L<charnames>.
+
+
+=item Constant is not %s reference
+
+(F) A constant value (perhaps declared using the C<use constant> pragma)
+is being dereferenced, but it amounts to the wrong type of reference.
+The message indicates the type of reference that was expected. This
+usually indicates a syntax error in dereferencing the constant value.
+See L<perlsub/"Constant Functions"> and L<constant>.
+
+=item Constant subroutine %s redefined
+
+(S) You redefined a subroutine which had previously been
+eligible for inlining. See L<perlsub/"Constant Functions"> for
+commentary and workarounds.
+
+=item Constant subroutine %s undefined
+
+(W misc) You undefined a subroutine which had previously been eligible
+for inlining. See L<perlsub/"Constant Functions"> for commentary and
+workarounds.
+
+=item Copy method did not return a reference
+
+(F) The method which overloads "=" is buggy. See
+L<overload/Copy Constructor>.
+
+=item CORE::%s is not a keyword
+
+(F) The CORE:: namespace is reserved for Perl keywords.
+
+=item corrupted regexp pointers
+
+(P) The regular expression engine got confused by what the regular
+expression compiler gave it.
+
+=item corrupted regexp program
+
+(P) The regular expression engine got passed a regexp program without a
+valid magic number.
+
+=item Corrupt malloc ptr 0x%lx at 0x%lx
+
+(P) The malloc package that comes with Perl had an internal failure.
+
+=item Count after length/code in unpack
+
+(F) You had an unpack template indicating a counted-length string, but
+you have also specified an explicit size for the string. See
+L<perlfunc/pack>.
+
+=item Deep recursion on subroutine "%s"
+
+(W recursion) This subroutine has called itself (directly or indirectly)
+100 times more than it has returned. This probably indicates an
+infinite recursion, unless you're writing strange benchmark programs, in
+which case it indicates something else.
+
+This threshold can be changed from 100, by recompiling the F<perl> binary,
+setting the C pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value.
+
+=item defined(@array) is deprecated
+
+(D deprecated) defined() is not usually useful on arrays because it
+checks for an undefined I<scalar> value. If you want to see if the
+array is empty, just use C<if (@array) { # not empty }> for example.
+
+=item defined(%hash) is deprecated
+
+(D deprecated) defined() is not usually useful on hashes because it
+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
+long for Perl to handle. You have to be seriously twisted to write code
+that triggers this error.
+
+=item Deprecated use of my() in false conditional
+
+(D deprecated) You used a declaration similar to C<my $x if 0>.
+There has been a long-standing bug in Perl that causes a lexical variable
+not to be cleared at scope exit when its declaration includes a false
+conditional. Some people have exploited this bug to achieve a kind of
+static variable. Since we intend to fix this bug, we don't want people
+relying on this behavior. You can achieve a similar static effect by
+declaring the variable in a separate block outside the function, eg
+
+ sub f { my $x if 0; return $x++ }
+
+becomes
+
+ { my $x; sub f { return $x++ } }
+
+Beginning with perl 5.9.4, you can also use C<state> variables to
+have lexicals that are initialized only once (see L<feature>):
+
+ sub f { state $x; return $x++ }
+
+=item DESTROY created new reference to dead object '%s'
+
+(F) A DESTROY() method created a new reference to the object which is
+just being DESTROYed. Perl is confused, and prefers to abort rather than
+to create a dangling reference.
+
+=item Did not produce a valid header
+
+See Server error.
+
+=item %s did not return a true value
+
+(F) A required (or used) file must return a true value to indicate that
+it compiled correctly and ran its initialization code correctly. It's
+traditional to end such a file with a "1;", though any true value would
+do. See L<perlfunc/require>.
+
+=item (Did you mean &%s instead?)
+
+(W) You probably referred to an imported subroutine &FOO as $FOO or some
+such.
+
+=item (Did you mean "local" instead of "our"?)
+
+(W misc) Remember that "our" does not localize the declared global
+variable. You have declared it again in the same lexical scope, which
+seems superfluous.
+
+=item (Did you mean $ or @ instead of %?)
+
+(W) You probably said %hash{$key} when you meant $hash{$key} or
+@hash{@keys}. On the other hand, maybe you just meant %hash and got
+carried away.
+
+=item Died
+
+(F) You passed die() an empty string (the equivalent of C<die "">) or
+you called it with no args and both C<$@> and C<$_> were empty.
+
+=item Document contains no data
+
+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 '/' does not take a repeat count
+
+(F) You cannot put a repeat count of any kind right after the '/' code.
+See L<perlfunc/pack>.
+
+=item Don't know how to handle magic of type '%s'
+
+(P) The internal handling of magical variables has been cursed.
+
+=item do_study: out of memory
+
+(P) This should have been caught by safemalloc() instead.
+
+=item (Do you need to predeclare %s?)
+
+(S syntax) This is an educated guess made in conjunction with the message
+"%s found where operator expected". It often means a subroutine or module
+name is being referenced that hasn't been declared yet. This may be
+because of ordering problems in your file, or because of a missing
+"sub", "package", "require", or "use" statement. If you're referencing
+something that isn't defined yet, you don't actually have to define the
+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 dump is not supported
+
+(F) Your machine doesn't support dump/undump.
+
+=item Duplicate free() ignored
+
+(S malloc) An internal routine called free() on something that had
+already been freed.
+
+=item Duplicate modifier '%c' after '%c' in %s
+
+(W) You have applied the same modifier more than once after a type
+in a pack template. See L<perlfunc/pack>.
+
+=item elseif should be elsif
+
+(S syntax) There is no keyword "elseif" in Perl because Larry thinks it's
+ugly. Your code will be interpreted as an attempt to call a method named
+"elseif" for the class returned by the following block. This is
+unlikely to be what you want.
+
+=item Empty %s
+
+(F) C<\p> and C<\P> are used to introduce a named Unicode property, as
+described in L<perlunicode> and L<perlre>. You used C<\p> or C<\P> in
+a regular expression without specifying the property name.
+
+=item entering effective %s failed
+
+(F) While under the C<use filetest> pragma, switching the real and
+effective uids or gids failed.
+
+=item %ENV is aliased to %s
+
+(F) You're running under taint mode, and the C<%ENV> variable has been
+aliased to another hash, so it doesn't reflect anymore the state of the
+program's environment. This is potentially insecure.
+
+=item Error converting file specification %s
+
+(F) An error peculiar to VMS. Because Perl may have to deal with file
+specifications in either VMS or Unix syntax, it converts them to a
+single form when it must operate on them directly. Either you've passed
+an invalid file specification to Perl, or you've found a case the
+conversion routines don't handle. Drat.
+
+=item %s: Eval-group in insecure regular expression
+
+(F) Perl detected tainted data when trying to compile a regular
+expression that contains the C<(?{ ... })> zero-width assertion, which
+is unsafe. See L<perlre/(?{ code })>, and L<perlsec>.
+
+=item %s: Eval-group not allowed at runtime, use re 'eval'
+
+(F) Perl tried to compile a regular expression containing the
+C<(?{ ... })> zero-width assertion at run time, as it would when the
+pattern contains interpolated values. Since that is a security risk, it
+is not allowed. If you insist, you may still do this by explicitly
+building the pattern from an interpolated string at run time and using
+that in an eval(). See L<perlre/(?{ code })>.
+
+=item %s: Eval-group not allowed, use re 'eval'
+
+(F) A regular expression contained the C<(?{ ... })> zero-width
+assertion, but that construct is only allowed when the C<use re 'eval'>
+pragma is in effect. See L<perlre/(?{ code })>.
+
+=item EVAL without pos change exceeded limit in regex; marked by <-- HERE in m/%s/
+
+(F) You used a pattern that nested too many EVAL calls without consuming
+any text. Restructure the pattern so that text is consumed.
+
+The <-- HERE shows in the regular expression about where the problem was
+discovered.
+
+=item Excessively long <> operator
+
+(F) The contents of a <> operator may not exceed the maximum size of a
+Perl identifier. If you're just trying to glob a long list of
+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.
+
+=item Exiting eval via %s
+
+(W exiting) You are exiting an eval by unconventional means, such as a
+goto, or a loop control statement.
+
+=item Exiting format via %s
+
+(W exiting) You are exiting a format by unconventional means, such as a
+goto, or a loop control statement.
+
+=item Exiting pseudo-block via %s
+
+(W exiting) You are exiting a rather special block construct (like a
+sort block or subroutine) by unconventional means, such as a goto, or a
+loop control statement. See L<perlfunc/sort>.
+
+=item Exiting subroutine via %s
+
+(W exiting) You are exiting a subroutine by unconventional means, such
+as a goto, or a loop control statement.
+
+=item Exiting substitution via %s
+
+(W exiting) You are exiting a substitution by unconventional means, such
+as a return, a goto, or a loop control statement.
+
+=item Explicit blessing to '' (assuming package main)
+
+(W misc) You are blessing a reference to a zero length string. This has
+the effect of blessing the reference into the package main. This is
+usually not what you want. Consider providing a default target package,
+e.g. bless($ref, $p || 'MyPackage');
+
+=item %s: Expression syntax
+
+(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 %s failed--call queue aborted
+
+(F) An untrapped exception was raised while executing a UNITCHECK,
+CHECK, INIT, or END subroutine. Processing of the remainder of the
+queue of such routines has been prematurely ended.
+
+=item False [] range "%s" in regex; marked by <-- HERE in m/%s/
+
+(W regexp) A character class range must start and end at a literal
+character, not another character class like C<\d> or C<[:alpha:]>. The "-"
+in your false range is interpreted as a literal "-". Consider quoting the
+"-", "\-". The <-- HERE shows in the regular expression about where the
+problem was discovered. See L<perlre>.
+
+=item Fatal VMS error at %s, line %d
+
+(P) An error peculiar to VMS. Something untoward happened in a VMS
+system service or RTL routine; Perl's exit status should provide more
+details. The filename in "at %s" and the line number in "line %d" tell
+you which section of the Perl source code is distressed.
+
+=item fcntl is not implemented
+
+(F) Your machine apparently doesn't implement fcntl(). What is this, a
+PDP-11 or something?
+
+=item FETCHSIZE returned a negative value
+
+(F) A tied array claimed to have a negative number of elements, which
+is not possible.
+
+=item Field too wide in 'u' format in pack
+
+(W pack) Each line in an uuencoded string start with a length indicator
+which can't encode values above 63. So there is no point in asking for
+a line length bigger than that. Perl will behave as if you specified
+C<u63> as format.
+
+=item Filehandle %s opened only for input
+
+(W io) You tried to write on a read-only filehandle. If you intended
+it to be a read-write filehandle, you needed to open it with "+<" or
+"+>" or "+>>" instead of with "<" or nothing. If you intended only to
+write the file, use ">" or ">>". See L<perlfunc/open>.
+
+=item Filehandle %s opened only for output
+
+(W io) You tried to read from a filehandle opened only for writing, If
+you intended it to be a read/write filehandle, you needed to open it
+with "+<" or "+>" or "+>>" instead of with "<" or nothing. If you
+intended only to read from the file, use "<". See L<perlfunc/open>.
+Another possibility is that you attempted to open filedescriptor 0
+(also known as STDIN) for output (maybe you closed STDIN earlier?).
+
+=item Filehandle %s reopened as %s only for input
+
+(W io) You opened for reading a filehandle that got the same filehandle id
+as STDOUT or STDERR. This occurred because you closed STDOUT or STDERR
+previously.
+
+=item Filehandle STDIN reopened as %s only for output
+
+(W io) You opened for writing a filehandle that got the same filehandle id
+as STDIN. This occurred because you closed STDIN previously.
+
+=item Final $ should be \$ or $name
+
+(F) You must now decide whether the final $ in a string was meant to be
+a literal dollar sign, or was meant to introduce a variable name that
+happens to be missing. So you have to put either the backslash or the
+name.
+
+=item flock() on closed filehandle %s
+
+(W closed) The filehandle you're attempting to flock() got itself closed
+some time before now. Check your control flow. flock() operates on
+filehandles. Are you attempting to call flock() on a dirhandle by the
+same name?
+
+=item Format not terminated
+
+(F) A format must be terminated by a line with a solitary dot. Perl got
+to the end of your file without finding such a line.
+
+=item Format %s redefined
+
+(W redefine) You redefined a format. To suppress this warning, say
+
+ {
+ no warnings 'redefine';
+ eval "format NAME =...";
+ }
+
+=item Found = in conditional, should be ==
+
+(W syntax) You said
+
+ if ($foo = 123)
+
+when you meant
+
+ if ($foo == 123)
+
+(or something like that).
+
+=item %s found where operator expected
+
+(S syntax) The Perl lexer knows whether to expect a term or an operator.
+If it sees what it knows to be a term when it was expecting to see an
+operator, it gives you this warning. Usually it indicates that an
+operator or delimiter was omitted, such as a semicolon.
+
+=item gdbm store returned %d, errno %d, key "%s"
+
+(S) A warning from the GDBM_File extension that a store failed.
+
+=item gethostent not implemented
+
+(F) Your C library apparently doesn't implement gethostent(), probably
+because if it did, it'd feel morally obligated to return every hostname
+on the Internet.
+
+=item get%sname() on closed socket %s
+
+(W closed) You tried to get a socket or peer socket name on a closed
+socket. Did you forget to check the return value of your socket() call?
+
+=item getpwnam returned invalid UIC %#o for user "%s"
+
+(S) A warning peculiar to VMS. The call to C<sys$getuai> underlying the
+C<getpwnam> operator returned an invalid UIC.
+
+=item getsockopt() on closed socket %s
+
+(W closed) You tried to get a socket option on a closed socket. Did you
+forget to check the return value of your socket() call? See
+L<perlfunc/getsockopt>.
+
+=item Global symbol "%s" requires explicit package name
+
+(F) You've said "use strict" or "use strict vars", which indicates
+that all variables must either be lexically scoped (using "my" or "state"),
+declared beforehand using "our", or explicitly qualified to say
+which package the global variable is in (using "::").
+
+=item glob failed (%s)
+
+(W glob) Something went wrong with the external program(s) used for
+C<glob> and C<< <*.c> >>. Usually, this means that you supplied a
+C<glob> pattern that caused the external program to fail and exit with a
+nonzero status. If the message indicates that the abnormal exit
+resulted in a coredump, this may also mean that your csh (C shell) is
+broken. If so, you should change all of the csh-related variables in
+config.sh: If you have tcsh, make the variables refer to it as if it
+were csh (e.g. C<full_csh='/usr/bin/tcsh'>); otherwise, make them all
+empty (except that C<d_csh> should be C<'undef'>) so that Perl will
+think csh is missing. In either case, after editing config.sh, run
+C<./Configure -S> and rebuild Perl.
+
+=item Glob not terminated
+
+(F) The lexer saw a left angle bracket in a place where it was expecting
+a term, so it's looking for the corresponding right angle bracket, and
+not finding it. Chances are you left some needed parentheses out
+earlier in the line, and you really meant a "less than".
+
+=item Got an error from DosAllocMem
+
+(P) An error peculiar to OS/2. Most probably you're using an obsolete
+version of Perl, and this should not happen anyway.
+
+=item goto must have label
+
+(F) Unlike with "next" or "last", you're not allowed to goto an
+unspecified destination. See L<perlfunc/goto>.
+
+=item ()-group starts with a count
+
+(F) A ()-group started with a count. A count is
+supposed to follow something: a template character or a ()-group.
+ See L<perlfunc/pack>.
+
+=item %s had compilation errors
+
+(F) The final summary message when a C<perl -c> fails.
+
+=item Had to create %s unexpectedly
+
+(S internal) A routine asked for a symbol from a symbol table that ought
+to have existed already, but for some reason it didn't, and had to be
+created on an emergency basis to prevent a core dump.
+
+=item Hash %%s missing the % in argument %d of %s()
+
+(D deprecated) Really old Perl let you omit the % on hash names in some
+spots. This is now heavily deprecated.
+
+=item %s has too many errors
+
+(F) The parser has given up trying to parse the program after 10 errors.
+Further error messages would likely be uninformative.
+
+=item Hexadecimal number > 0xffffffff non-portable
+
+(W portable) The hexadecimal number you specified is larger than 2**32-1
+(4294967295) and therefore non-portable between systems. See
+L<perlport> for more on portability concerns.
+
+=item Identifier too long
+
+(F) Perl limits identifiers (names for variables, functions, etc.) to
+about 250 characters for simple names, and somewhat more for compound
+names (like C<$A::B>). You've exceeded Perl's limits. Future versions
+of Perl are likely to eliminate these arbitrary limitations.
+
+=item Ignoring %s in character class in regex; marked by <-- HERE in m/%s/
+
+(W) Named Unicode character escapes (\N{...}) may return multi-char
+or zero length sequences. When such an escape is used in a character class
+its behaviour is not well defined. Check that the correct escape has
+been used, and the correct charname handler is in scope.
+
+=item Illegal binary digit %s
+
+(F) You used a digit other than 0 or 1 in a binary number.
+
+=item Illegal binary digit %s ignored
+
+(W digit) You may have tried to use a digit other than 0 or 1 in a
+binary number. Interpretation of the binary number stopped before the
+offending digit.
+
+=item Illegal character %s (carriage return)
+
+(F) Perl normally treats carriage returns in the program text as it
+would any other whitespace, which means you should never see this error
+when Perl was built using standard options. For some reason, your
+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 declaration of anonymous subroutine
+
+(F) When using the C<sub> keyword to construct an anonymous subroutine,
+you must always specify a block of code. See L<perlsub>.
+
+=item Illegal declaration of subroutine %s
+
+(F) A subroutine was not declared correctly. See L<perlsub>.
+
+=item Illegal division by zero
+
+(F) You tried to divide a number by 0. Either something was wrong in
+your logic, or you need to put a conditional in to guard against
+meaningless input.
+
+=item Illegal hexadecimal digit %s ignored
+
+(W digit) You may have tried to use a character other than 0 - 9 or
+A - F, a - f in a hexadecimal number. Interpretation of the hexadecimal
+number stopped before the illegal character.
+
+=item Illegal modulus zero
+
+(F) You tried to divide a number by 0 to get the remainder. Most
+numbers don't take to this kindly.
+
+=item Illegal number of bits in vec
+
+(F) The number of bits in vec() (the third argument) must be a power of
+two from 1 to 32 (or 64, if your platform supports that).
+
+=item Illegal octal digit %s
+
+(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 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<-[CDIMUdmtw]>.
+
+=item Ill-formed CRTL environ value "%s"
+
+(W internal) A warning peculiar to VMS. Perl tried to read the CRTL's
+internal environ array, and encountered an element without the C<=>
+delimiter used to separate keys from values. The element is ignored.
+
+=item Ill-formed message in prime_env_iter: |%s|
+
+(W internal) A warning peculiar to VMS. Perl tried to read a logical
+name or CLI symbol definition when preparing to iterate over %ENV, and
+didn't see the expected delimiter between key and value, so the line was
+ignored.
+
+=item (in cleanup) %s
+
+(W misc) This prefix usually indicates that a DESTROY() method raised
+the indicated exception. Since destructors are usually called by the
+system at arbitrary points during execution, and often a vast number of
+times, the warning is issued only once for any number of failures that
+would otherwise result in the same message being repeated.
+
+Failure of user callbacks dispatched using the C<G_KEEPERR> flag could
+also result in this warning. See L<perlcall/G_KEEPERR>.
+
+=item Inconsistent hierarchy during C3 merge of class '%s': merging failed on parent '%s'
+
+(F) The method resolution order (MRO) of the given class is not
+C3-consistent, and you have enabled the C3 MRO for this class. See the C3
+documentation in L<mro> for more information.
+
+=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 Infinite recursion in regex; marked by <-- HERE in m/%s/
+
+(F) You used a pattern that references itself without consuming any input
+text. You should check the pattern to ensure that recursive patterns
+either consume text or fail.
+
+The <-- HERE shows in the regular expression about where the problem was
+discovered.
+
+=item Initialization of state variables in list context currently forbidden
+
+(F) Currently the implementation of "state" only permits the initialization
+of scalar variables in scalar context. Re-write C<state ($a) = 42> as
+C<state $a = 42> to change from list to scalar context. Constructions such
+as C<state (@a) = foo()> will be supported in a future perl release.
+
+=item Insecure dependency in %s
+
+(F) You tried to do something that the tainting mechanism didn't like.
+The tainting mechanism is turned on when you're running setuid or
+setgid, or when you specify B<-T> to turn it on explicitly. The
+tainting mechanism labels all data that's derived directly or indirectly
+from the user, who is considered to be unworthy of your trust. If any
+such data is used in a "dangerous" operation, you get this error. See
+L<perlsec> for more information.
+
+=item Insecure directory in %s
+
+(F) You can't use system(), exec(), or a piped open in a setuid or
+setgid script if C<$ENV{PATH}> contains a directory that is writable by
+the world. Also, the PATH must not contain any relative directory.
+See L<perlsec>.
+
+=item Insecure $ENV{%s} while running %s
+
+(F) You can't use system(), exec(), or a piped open in a setuid or
+setgid script if any of C<$ENV{PATH}>, C<$ENV{IFS}>, C<$ENV{CDPATH}>,
+C<$ENV{ENV}>, C<$ENV{BASH_ENV}> or C<$ENV{TERM}> are derived from data
+supplied (or potentially supplied) by the user. The script must set
+the path to a known value, using trustworthy data. See L<perlsec>.
+
+=item Integer overflow in %s number
+
+(W overflow) The hexadecimal, octal or binary number you have specified
+either as a literal or as an argument to hex() or oct() is too big for
+your architecture, and has been converted to a floating point number.
+On a 32-bit architecture the largest hexadecimal, octal or binary number
+representable without overflow is 0xFFFFFFFF, 037777777777, or
+0b11111111111111111111111111111111 respectively. Note that Perl
+transparently promotes all numbers to a floating point representation
+internally--subject to loss of precision errors in subsequent
+operations.
+
+=item Integer overflow in format string for %s
+
+(F) The indexes and widths specified in the format string of C<printf()>
+or C<sprintf()> are too large. The numbers must not overflow the size of
+integers for your architecture.
+
+=item Integer overflow in version
+
+(F) Some portion of a version initialization is too large for the
+size of integers for your architecture. This is not a warning
+because there is no rational reason for a version to try and use a
+element larger than typically 2**32. This is usually caused by
+trying to use some odd mathematical operation as a version, like
+100/9.
+
+=item Internal disaster in regex; marked by <-- HERE in m/%s/
+
+(P) Something went badly wrong in the regular expression parser.
+The <-- HERE shows in the regular expression about where the problem was
+discovered.
+
+=item Internal inconsistency in tracking vforks
+
+(S) A warning peculiar to VMS. Perl keeps track of the number of times
+you've called C<fork> and C<exec>, to determine whether the current call
+to C<exec> should affect the current script or a subprocess (see
+L<perlvms/"exec LIST">). Somehow, this count has become scrambled, so
+Perl is making a guess and treating this C<exec> as a request to
+terminate the Perl script and execute the specified command.
+
+=item Internal urp in regex; marked by <-- HERE in m/%s/
+
+(P) Something went badly awry in the regular expression parser. The
+<-- HERE shows in the regular expression about where the problem was
+discovered.
+
+=item %s (...) interpreted as function
+
+(W syntax) You've run afoul of the rule that says that any list operator
+followed by parentheses turns into a function, with all the list
+operators arguments found inside the parentheses. See
+L<perlop/Terms and List Operators (Leftward)>.
+
+=item Invalid %s attribute: %s
+
+The indicated attribute for a subroutine or variable was not recognized
+by Perl or by a user-supplied handler. See L<attributes>.
+
+=item Invalid %s attributes: %s
+
+The indicated attributes for a subroutine or variable were not
+recognized by Perl or by a user-supplied handler. See L<attributes>.
+
+=item Invalid conversion in %s: "%s"
+
+(W printf) Perl does not understand the given format conversion. See
+L<perlfunc/sprintf>.
+
+=item Invalid escape in the specified encoding in regex; marked by <-- HERE in m/%s/
+
+(W regexp) The numeric escape (for example C<\xHH>) of value < 256
+didn't correspond to a single character through the conversion
+from the encoding specified by the encoding pragma.
+The escape was replaced with REPLACEMENT CHARACTER (U+FFFD) instead.
+The <-- HERE shows in the regular expression about where the
+escape was discovered.
+
+=item Invalid mro name: '%s'
+
+(F) You tried to C<mro::set_mro("classname", "foo")>
+or C<use mro 'foo'>, where C<foo> is not a valid method resolution order (MRO).
+(Currently, the only valid ones are C<dfs> and C<c3>). See L<mro>.
+
+=item Invalid [] range "%s" in regex; marked by <-- HERE in m/%s/
+
+(F) The range specified in a character class had a minimum character
+greater than the maximum character. One possibility is that you forgot the
+C<{}> from your ending C<\x{}> - C<\x> without the curly braces can go only
+up to C<ff>. The <-- HERE shows in the regular expression about where the
+problem was discovered. See L<perlre>.
+
+=item Invalid range "%s" in transliteration operator
+
+(F) The range specified in the tr/// or y/// operator had a minimum
+character greater than the maximum character. See L<perlop>.
+
+=item Invalid separator character %s in attribute list
+
+(F) Something other than a colon or whitespace was seen between the
+elements of an attribute list. If the previous attribute had a
+parenthesised parameter list, perhaps that list was terminated too soon.
+See L<attributes>.
+
+=item Invalid separator character %s in PerlIO layer specification %s
+
+(W layer) When pushing layers onto the Perl I/O system, something other than a
+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.
+
+=item Invalid type '%s' in %s
+
+(F) The given character is not a valid pack or unpack type.
+See L<perlfunc/pack>.
+(W) The given character is not a valid pack or unpack type but used to be
+silently ignored.
+
+=item Invalid version format (multiple underscores)
+
+(F) Versions may contain at most a single underscore, which signals
+that the version is a beta release. See L<version> for the allowed
+version formats.
+
+=item Invalid version format (underscores before decimal)
+
+(F) Versions may not contain decimals after the optional underscore.
+See L<version> for the allowed version formats.
+
+=item ioctl is not implemented
+
+(F) Your machine apparently doesn't implement ioctl(), which is pretty
+strange for a machine that supports C.
+
+=item ioctl() on unopened %s
+
+(W unopened) You tried ioctl() on a filehandle that was never opened.
+Check you control flow and number of arguments.
+
+=item IO layers (like "%s") unavailable
+
+(F) Your Perl has not been configured to have PerlIO, and therefore
+you cannot use IO layers. To have PerlIO Perl must be configured
+with 'useperlio'.
+
+=item IO::Socket::atmark not implemented on this architecture
+
+(F) Your machine doesn't implement the sockatmark() functionality,
+neither as a system call or an ioctl call (SIOCATMARK).
+
+=item $* is no longer supported
+
+(S deprecated, syntax) The special variable C<$*>, deprecated in older perls, has
+been removed as of 5.9.0 and is no longer supported. In previous versions of perl the use of
+C<$*> enabled or disabled multi-line matching within a string.
+
+Instead of using C<$*> you should use the C</m> (and maybe C</s>) regexp
+modifiers. (In older versions: when C<$*> was set to a true value then all regular
+expressions behaved as if they were written using C</m>.)
+
+=item $# is no longer supported
+
+(S deprecated, syntax) The special variable C<$#>, deprecated in older perls, has
+been removed as of 5.9.3 and is no longer supported. You should use the
+printf/sprintf functions instead.
+
+=item `%s' is not a code 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 overload) You tried to overload a constant type the overload package is
+unaware of.
+
+=item junk on end of regexp
+
+(P) The regular expression parser is confused.
+
+=item Label not found for "last %s"
+
+(F) You named a loop to break out of, but you're not currently in a loop
+of that name, not even if you count where you were called from. See
+L<perlfunc/last>.
+
+=item Label not found for "next %s"
+
+(F) You named a loop to continue, but you're not currently in a loop of
+that name, not even if you count where you were called from. See
+L<perlfunc/last>.
+
+=item Label not found for "redo %s"
+
+(F) You named a loop to restart, but you're not currently in a loop of
+that name, not even if you count where you were called from. See
+L<perlfunc/last>.
+
+=item leaving effective %s failed
+
+(F) While under the C<use filetest> pragma, switching the real and
+effective uids or gids failed.
+
+=item length/code after end of string in unpack
+
+(F) While unpacking, the string buffer was already used up when an unpack
+length/code combination tried to obtain more data. This results in
+an undefined value for the length. See L<perlfunc/pack>.
+
+=item listen() on closed socket %s
+
+(W closed) You tried to do a listen on a closed socket. Did you forget
+to check the return value of your socket() call? See
+L<perlfunc/listen>.
+
+=item Lookbehind longer than %d not implemented in regex m/%s/
+
+(F) There is currently a limit on the length of string which lookbehind can
+handle. This restriction may be eased in a future release.
+
+=item lstat() on filehandle %s
+
+(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.)
+
+=item Lvalue subs returning %s not implemented yet
+
+(F) Due to limitations in the current implementation, array and hash
+values cannot be returned in subroutines used in lvalue context. See
+L<perlsub/"Lvalue subroutines">.
+
+=item Malformed integer in [] in pack
+
+(F) Between the brackets enclosing a numeric repeat count only digits
+are permitted. See L<perlfunc/pack>.
+
+=item Malformed integer in [] in unpack
+
+(F) Between the brackets enclosing a numeric repeat count only digits
+are permitted. See L<perlfunc/pack>.
+
+=item Malformed PERLLIB_PREFIX
+
+(F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form
+
+ prefix1;prefix2
+
+or
+ prefix1 prefix2
+
+with nonempty prefix1 and prefix2. If C<prefix1> is indeed a prefix of
+a builtin library search path, prefix2 is substituted. The error may
+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)
+
+(S utf8) (F) Perl detected a string that didn't comply with UTF-8
+encoding rules, even though it had the UTF8 flag on.
+
+One possible cause is that you set the UTF8 flag yourself for data that
+you thought to be in UTF-8 but it wasn't (it was for example legacy
+8-bit data). To guard against this, you can use Encode::decode_utf8.
+
+If you use the C<:encoding(UTF-8)> PerlIO layer for input, invalid byte
+sequences are handled gracefully, but if you use C<:utf8>, the flag is
+set without validating the data, possibly resulting in this error
+message.
+
+See also L<Encode/"Handling Malformed Data">.
+
+=item Malformed UTF-16 surrogate
+
+Perl thought it was reading UTF-16 encoded character data but while
+doing it Perl met a malformed Unicode surrogate.
+
+=item Malformed UTF-8 string in pack
+
+(F) You tried to pack something that didn't comply with UTF-8 encoding
+rules and perl was unable to guess how to make more progress.
+
+=item Malformed UTF-8 string in unpack
+
+(F) You tried to unpack something that didn't comply with UTF-8 encoding
+rules and perl was unable to guess how to make more progress.
+
+=item Malformed UTF-8 string in '%c' format in unpack
+
+(F) You tried to unpack something that didn't comply with UTF-8 encoding
+rules and perl was unable to guess how to make more progress.
+
+=item Maximal count of pending signals (%s) exceeded
+
+(F) Perl aborted due to a too important number of signals pending. This
+usually indicates that your operating system tried to deliver signals
+too fast (with a very high priority), starving the perl process from
+resources it would need to reach a point where it can process signals
+safely. (See L<perlipc/"Deferred Signals (Safe Signals)">.)
+
+=item %s matches null string many times in regex; marked by <-- HERE in m/%s/
+
+(W regexp) The pattern you've specified would be an infinite loop if the
+regular expression engine didn't specifically check for that. The <-- HERE
+shows in the regular expression about where the problem was discovered.
+See L<perlre>.
+
+=item "%s" may clash with future reserved word
+
+(W) This warning may be due to running a perl5 script through a perl4
+interpreter, especially if the word that is being warned about is
+"use" or "my".
+
+=item % may not be used in pack
+
+(F) You can't pack a string by supplying a checksum, because the
+checksumming process loses information, and you can't go the other way.
+See L<perlfunc/unpack>.
+
+=item Method for operation %s not found in package %s during blessing
+
+(F) An attempt was made to specify an entry in an overloading table that
+doesn't resolve to a valid subroutine. See L<overload>.
+
+=item Method %s not permitted
+
+See Server error.
+
+=item Might be a runaway multi-line %s string starting on line %d
+
+(S) An advisory indicating that the previous error may have been caused
+by a missing delimiter on a string or pattern, because it eventually
+ended earlier on the current line.
+
+=item Misplaced _ in number
+
+(W syntax) An underscore (underbar) in a numeric constant did not
+separate two digits.
+
+=item Missing argument to -%c
+
+(F) The argument to the indicated command line switch must follow
+immediately after the switch, without intervening spaces.
+
+=item Missing %sbrace%s on \N{}
+
+(F) Wrong syntax of character name literal C<\N{charname}> within
+double-quotish context.
+
+=item Missing comma after first argument to %s function
+
+(F) While certain functions allow you to specify a filehandle or an
+"indirect object" before the argument list, this ain't one of them.
+
+=item Missing command in piped open
+
+(W pipe) You used the C<open(FH, "| command")> or
+C<open(FH, "command |")> construction, but the command was missing or
+blank.
+
+=item Missing control char name in \c
+
+(F) A double-quoted string ended with "\c", without the required control
+character name.
+
+=item Missing name in "my sub"
+
+(F) The reserved syntax for lexically scoped subroutines requires that
+they have a name with which they can be found.
+
+=item Missing $ on loop variable
+
+(F) Apparently you've been programming in B<csh> too much. Variables
+are always mentioned with the $ in Perl, unlike in the shells, where it
+can vary from one line to the next.
+
+=item (Missing operator before %s?)
+
+(S syntax) This is an educated guess made in conjunction with the message
+"%s found where operator expected". Often the missing operator is a comma.
+
+=item Missing right brace on %s
+
+(F) Missing right brace in C<\x{...}>, C<\p{...}> or C<\P{...}>.
+
+=item Missing right curly or square bracket
+
+(F) The lexer counted more opening curly or square brackets than closing
+ones. As a general rule, you'll find it's missing near the place you
+were last editing.
+
+=item (Missing semicolon on previous line?)
+
+(S syntax) This is an educated guess made in conjunction with the message
+"%s found where operator expected". Don't automatically put a semicolon on
+the previous line just because you saw this message.
+
+=item Modification of a read-only value attempted
+
+(F) You tried, directly or indirectly, to change the value of a
+constant. You didn't, of course, try "2 = 1", because the compiler
+catches that. But an easy way to do the same thing is:
+
+ sub mod { $_[0] = 1 }
+ mod(2);
+
+Another way is to assign to a substr() that's off the end of the string.
+
+Yet another way is to assign to a C<foreach> loop I<VAR> when I<VAR>
+is aliased to a constant in the look I<LIST>:
+
+ $x = 1;
+ foreach my $n ($x, 2) {
+ $n *= 2; # modifies the $x, but fails on attempt to modify the 2
+ }
+
+=item Modification of non-creatable array value attempted, %s
+
+(F) You tried to make an array value spring into existence, and the
+subscript was probably negative, even counting from end of the array
+backwards.
+
+=item Modification of non-creatable hash value attempted, %s
+
+(P) You tried to make a hash value spring into existence, and it
+couldn't be created for some peculiar reason.
+
+=item Module name must be constant
+
+(F) Only a bare module name is allowed as the first argument to a "use".
+
+=item Module name required with -%c option
+
+(F) The C<-M> or C<-m> options say that Perl should load some module, but
+you omitted the name of the module. Consult L<perlrun> for full details
+about C<-M> and C<-m>.
+
+=item More than one argument to open
+
+(F) The C<open> function has been asked to open multiple files. This
+can happen if you are trying to open a pipe to a command that takes a
+list of arguments, but have forgotten to specify a piped open mode.
+See L<perlfunc/open> for details.
+
+=item msg%s not implemented
+
+(F) You don't have System V message IPC on your system.
+
+=item Multidimensional syntax %s not supported
+
+(W syntax) Multidimensional arrays aren't written like C<$foo[1,2,3]>.
+They're written like C<$foo[1][2][3]>, as in C.
+
+=item '/' must follow a numeric type in unpack
+
+(F) You had an unpack template that contained a '/', but this did not
+follow some unpack specification producing a numeric value.
+See L<perlfunc/pack>.
+
+=item "my sub" not yet implemented
+
+(F) Lexically scoped subroutines are not yet implemented. Don't try
+that yet.
+
+=item "%s" variable %s can't be in a package
+
+(F) Lexically scoped variables aren't in a package, so it doesn't make
+sense to try to declare one with a package qualifier on the front. Use
+local() if you want to localize a package variable.
+
+=item Name "%s::%s" used only once: possible typo
+
+(W once) Typographical errors often show up as unique variable names.
+If you had a good reason for having a unique name, then just mention it
+again somehow to suppress the message. The C<our> declaration is
+provided for this purpose.
+
+NOTE: This warning detects symbols that have been used only once so $c, @c,
+%c, *c, &c, sub c{}, c(), and c (the filehandle or format) are considered
+the same; if a program uses $c only once but also uses any of the others it
+will not trigger this warning.
+
+=item Negative '/' count in unpack
+
+(F) The length count obtained from a length/code unpack operation was
+negative. See L<perlfunc/pack>.
+
+=item Negative length
+
+(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
+things like ** or +* or ?* are illegal. The <-- HERE shows in the regular
+expression about where the problem was discovered.
+
+Note that the minimal matching quantifiers, C<*?>, C<+?>, and
+C<??> appear to be nested quantifiers, but aren't. See L<perlre>.
+
+=item %s never introduced
+
+(S internal) The symbol in question was declared but somehow went out of
+scope before it could possibly have been used.
+
+=item next::method/next::can/maybe::next::method cannot find enclosing method
+
+(F) C<next::method> needs to be called within the context of a
+real method in a real package, and it could not find such a context.
+See L<mro>.
+
+=item No %s allowed while running setuid
+
+(F) Certain operations are deemed to be too insecure for a setuid or
+setgid script to even be allowed to attempt. Generally speaking there
+will be another way to do what you want that is, if not secure, at least
+securable. See L<perlsec>.
+
+=item No comma allowed after %s
+
+(F) A list operator that has a filehandle or "indirect object" is not
+allowed to have a comma between that and the following arguments.
+Otherwise it'd be just another one of the arguments.
+
+One possible cause for this is that you expected to have imported a
+constant to your name space with B<use> or B<import> while no such
+importing took place, it may for example be that your operating system
+does not support that particular constant. Hopefully you did use an
+explicit import list for the constants you expect to see, please see
+L<perlfunc/use> and L<perlfunc/import>. While an explicit import list
+would probably have caught this error earlier it naturally does not
+remedy the fact that your operating system still does not support that
+constant. Maybe you have a typo in the constants of the symbol import
+list of B<use> or B<import> or in the constant name at the line where
+this error was triggered?
+
+=item No command into which to pipe on command line
+
+(F) An error peculiar to VMS. Perl handles its own command line
+redirection, and found a '|' at the end of the command line, so it
+doesn't know where you want to pipe the output from this command.
+
+=item No DB::DB routine defined
+
+(F) The currently executing code was compiled with the B<-d> switch, but
+for some reason the current debugger (e.g. F<perl5db.pl> or a C<Devel::>
+module) didn't define a routine to be called at the beginning of each
+statement.
+
+=item No dbm on this machine
+
+(P) This is counted as an internal error, because every machine should
+supply dbm nowadays, because Perl comes with SDBM. See L<SDBM_File>.
+
+=item No DB::sub routine defined
+
+(F) The currently executing code was compiled with the B<-d> switch, but
+for some reason the current debugger (e.g. F<perl5db.pl> or a C<Devel::>
+module) didn't define a C<DB::sub> routine to be called at the beginning
+of each ordinary subroutine call.
+
+=item No B<-e> allowed in setuid scripts
+
+(F) A setuid script can't be specified by the user.
+
+=item No error file after 2> or 2>> on command line
+
+(F) An error peculiar to VMS. Perl handles its own command line
+redirection, and found a '2>' or a '2>>' on the command line, but can't
+find the name of the file to which to write data destined for stderr.
+
+=item No group ending character '%c' found in template
+
+(F) A pack or unpack template has an opening '(' or '[' without its
+matching counterpart. See L<perlfunc/pack>.
+
+=item No input file after < on command line
+
+(F) An error peculiar to VMS. Perl handles its own command line
+redirection, and found a '<' on the command line, but can't find the
+name of the file from which to read data for stdin.
+
+=item No #! line
+
+(F) The setuid emulator requires that scripts have a well-formed #! line
+even on machines that don't support the #! construct.
+
+=item No next::method '%s' found for %s
+
+(F) C<next::method> found no further instances of this method name
+in the remaining packages of the MRO of this class. If you don't want
+it throwing an exception, use C<maybe::next::method>
+or C<next::can>. See L<mro>.
+
+=item "no" not allowed in expression
+
+(F) The "no" keyword is recognized and executed at compile time, and
+returns no useful value. See L<perlmod>.
+
+=item No output file after > on command line
+
+(F) An error peculiar to VMS. Perl handles its own command line
+redirection, and found a lone '>' at the end of the command line, so it
+doesn't know where you wanted to redirect stdout.
+
+=item No output file after > or >> on command line
+
+(F) An error peculiar to VMS. Perl handles its own command line
+redirection, and found a '>' or a '>>' on the command line, but can't
+find the name of the file to which to write data destined for stdout.
+
+=item No package name allowed for variable %s in "our"
+
+(F) Fully qualified variable names are not allowed in "our"
+declarations, because that doesn't make much sense under existing
+semantics. Such syntax is reserved for future extensions.
+
+=item No Perl script found in input
+
+(F) You called C<perl -x>, but no line was found in the file beginning
+with #! and containing the word "perl".
+
+=item No setregid available
+
+(F) Configure didn't find anything resembling the setregid() call for
+your system.
+
+=item No setreuid available
+
+(F) Configure didn't find anything resembling the setreuid() call for
+your system.
+
+=item No %s specified for -%c
+
+(F) The indicated command line switch needs a mandatory argument, but
+you haven't specified one.
+
+=item No such class field "%s" in variable %s of type %s
+
+(F) You tried to access a key from a hash through the indicated typed variable
+but that key is not allowed by the package of the same type. The indicated
+package has restricted the set of allowed keys using the L<fields> pragma.
+
+=item No such class %s
+
+(F) You provided a class qualifier in a "my", "our" or "state" declaration, but
+this class doesn't exist at this point in your program.
+
+=item No such hook: %s
+
+(F) You specified a signal hook that was not recognized by Perl. Currently, Perl
+accepts C<__DIE__> and C<__WARN__> as valid signal hooks
+
+=item No such pipe open
+
+(P) An error peculiar to VMS. The internal routine my_pclose() tried to
+close a pipe which hadn't been opened. This should have been caught
+earlier as an attempt to close an unopened filehandle.
+
+=item No such signal: SIG%s
+
+(W signal) You specified a signal name as a subscript to %SIG that was
+not recognized. Say C<kill -l> in your shell to see the valid signal
+names on your system.
+
+=item Not a CODE reference
+
+(F) Perl was trying to evaluate a reference to a code value (that is, a
+subroutine), but found a reference to something else instead. You can
+use the ref() function to find out what kind of ref it really was. See
+also L<perlref>.
+
+=item Not a format reference
+
+(F) I'm not sure how you managed to generate a reference to an anonymous
+format, but this indicates you did, and that it didn't exist.
+
+=item Not a GLOB reference
+
+(F) Perl was trying to evaluate a reference to a "typeglob" (that is, a
+symbol table entry that looks like C<*foo>), but found a reference to
+something else instead. You can use the ref() function to find out what
+kind of ref it really was. See L<perlref>.
+
+=item Not a HASH reference
+
+(F) Perl was trying to evaluate a reference to a hash value, but found a
+reference to something else instead. You can use the ref() function to
+find out what kind of ref it really was. See L<perlref>.
+
+=item Not an ARRAY reference
+
+(F) Perl was trying to evaluate a reference to an array value, but found
+a reference to something else instead. You can use the ref() function
+to find out what kind of ref it really was. See L<perlref>.
+
+=item Not a perl script
+
+(F) The setuid emulator requires that scripts have a well-formed #! line
+even on machines that don't support the #! construct. The line must
+mention perl.
+
+=item Not a SCALAR reference
+
+(F) Perl was trying to evaluate a reference to a scalar value, but found
+a reference to something else instead. You can use the ref() function
+to find out what kind of ref it really was. See L<perlref>.
+
+=item Not a subroutine reference
+
+(F) Perl was trying to evaluate a reference to a code value (that is, a
+subroutine), but found a reference to something else instead. You can
+use the ref() function to find out what kind of ref it really was. See
+also L<perlref>.
+
+=item Not a subroutine reference in overload table
+
+(F) An attempt was made to specify an entry in an overloading table that
+doesn't somehow point to a valid subroutine. See L<overload>.
+
+=item Not enough arguments for %s
+
+(F) The function requires more arguments than you specified.
+
+=item Not enough format arguments
+
+(W syntax) A format specified more picture fields than the next line
+supplied. See L<perlform>.
+
+=item %s: not found
+
+(A) You've accidentally run your script through the Bourne shell instead
+of Perl. Check the #! line, or manually feed your script into Perl
+yourself.
+
+=item no UTC offset information; assuming local time is UTC
+
+(S) A warning peculiar to VMS. Perl was unable to find the local
+timezone offset, so it's assuming that local system time is equivalent
+to UTC. If it's not, define the logical name
+F<SYS$TIMEZONE_DIFFERENTIAL> to translate to the number of seconds which
+need to be added to UTC to get local time.
+
+=item Non-string passed as bitmask
+
+(W misc) A number has been passed as a bitmask argument to select().
+Use the vec() function to construct the file descriptor bitmasks for
+select. See L<perlfunc/select>
+
+=item Null filename used
+
+(F) You can't require the null filename, especially because on many
+machines that means the current directory! See L<perlfunc/require>.
+
+=item NULL OP IN RUN
+
+(P debugging) Some internal routine called run() with a null opcode
+pointer.
+
+=item Null picture in formline
+
+(F) The first argument to formline must be a valid format picture
+specification. It was found to be empty, which probably means you
+supplied it an uninitialized value. See L<perlform>.
+
+=item Null realloc
+
+(P) An attempt was made to realloc NULL.
+
+=item NULL regexp argument
+
+(P) The internal pattern matching routines blew it big time.
+
+=item NULL regexp parameter
+
+(P) The internal pattern matching routines are out of their gourd.
+
+=item Number too long
+
+(F) Perl limits the representation of decimal numbers in programs to
+about 250 characters. You've exceeded that length. Future
+versions of Perl are likely to eliminate this arbitrary limitation. In
+the meantime, try using scientific notation (e.g. "1e6" instead of
+"1_000_000").
+
+=item Octal number in vector unsupported
+
+(F) Numbers with a leading C<0> are not currently allowed in vectors.
+The octal number interpretation of such numbers may be supported in a
+future version.
+
+=item Octal number > 037777777777 non-portable
+
+(W portable) The octal number you specified is larger than 2**32-1
+(4294967295) and therefore non-portable between systems. See
+L<perlport> for more on portability concerns.
+
+See also L<perlport> for writing portable code.
+
+=item Odd number of arguments for overload::constant
+
+(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
+
+(W misc) You specified an odd number of elements to initialize a hash,
+which is odd, because hashes come in key/value pairs.
+
+=item Offset outside string
+
+(F, W layer) You tried to do a read/write/send/recv/seek operation
+with an offset pointing outside the buffer. This is difficult to
+imagine. The sole exceptions to this are that zero padding will
+take place when going past the end of the string when either
+C<sysread()>ing a file, or when seeking past the end of a scalar opened
+for I/O (in anticipation of future reads and to imitate the behaviour
+with real files).
+
+=item %s() on unopened %s
+
+(W unopened) An I/O operation was attempted on a filehandle that was
+never initialized. You need to do an open(), a sysopen(), or a socket()
+call, or call a constructor from the FileHandle package.
+
+=item -%s on unopened filehandle %s
+
+(W unopened) You tried to invoke a file test operator on a filehandle
+that isn't open. Check your control flow. See also L<perlfunc/-X>.
+
+=item oops: oopsAV
+
+(S internal) An internal warning that the grammar is screwed up.
+
+=item oops: oopsHV
+
+(S internal) An internal warning that the grammar is screwed up.
+
+=item Opening dirhandle %s also as a file
+
+(W io deprecated) You used open() to associate a filehandle to
+a symbol (glob or scalar) that already holds a dirhandle.
+Although legal, this idiom might render your code confusing
+and is deprecated.
+
+=item Opening filehandle %s also as a directory
+
+(W io deprecated) You used opendir() to associate a dirhandle to
+a symbol (glob or scalar) that already holds a filehandle.
+Although legal, this idiom might render your code confusing
+and is deprecated.
+
+=item Operation "%s": no method found, %s
+
+(F) An attempt was made to perform an overloaded operation for which no
+handler was defined. While some handlers can be autogenerated in terms
+of other handlers, there is no default handler for any operation, unless
+C<fallback> overloading key is specified to be true. See L<overload>.
+
+=item Operator or semicolon missing before %s
+
+(S ambiguous) You used a variable or subroutine call where the parser
+was expecting an operator. The parser has assumed you really meant to
+use an operator, but this is highly likely to be incorrect. For
+example, if you say "*foo *foo" it will be interpreted as if you said
+"*foo * 'foo'".
+
+=item "our" variable %s redeclared
+
+(W misc) You seem to have already declared the same global once before
+in the current lexical scope.
+
+=item Out of memory!
+
+(X) The malloc() function returned 0, indicating there was insufficient
+remaining memory (or virtual memory) to satisfy the request. Perl has
+no option but to exit immediately.
+
+At least in Unix you may be able to get past this by increasing your
+process datasize limits: in csh/tcsh use C<limit> and
+C<limit datasize n> (where C<n> is the number of kilobytes) to check
+the current limits and change them, and in ksh/bash/zsh use C<ulimit -a>
+and C<ulimit -d n>, respectively.
+
+=item Out of memory during %s extend
+
+(X) An attempt was made to extend an array, a list, or a string beyond
+the largest possible memory allocation.
+
+=item Out of memory during "large" request for %s
+
+(F) The malloc() function returned 0, indicating there was insufficient
+remaining memory (or virtual memory) to satisfy the request. However,
+the request was judged large enough (compile-time default is 64K), so a
+possibility to shut down by trapping this error is granted.
+
+=item Out of memory during request for %s
+
+(X|F) The malloc() function returned 0, indicating there was
+insufficient remaining memory (or virtual memory) to satisfy the
+request.
+
+The request was judged to be small, so the possibility to trap it
+depends on the way perl was compiled. By default it is not trappable.
+However, if compiled for this, Perl may use the contents of C<$^M> as an
+emergency pool after die()ing with this message. In this case the error
+is trappable I<once>, and the error message will include the line and file
+where the failed request happened.
+
+=item Out of memory during ridiculously large request
+
+(F) You can't allocate more than 2^31+"small amount" bytes. This error
+is most likely to be caused by a typo in the Perl program. e.g.,
+C<$arr[time]> instead of C<$arr[$time]>.
+
+=item Out of memory for yacc stack
+
+(F) The yacc parser wanted to grow its stack so it could continue
+parsing, but realloc() wouldn't give it more memory, virtual or
+otherwise.
+
+=item '.' outside of string in pack
+
+(F) The argument to a '.' in your template tried to move the working
+position to before the start of the packed string being built.
+
+=item '@' outside of string in unpack
+
+(F) You had a template that specified an absolute position outside
+the string being unpacked. See L<perlfunc/pack>.
+
+=item '@' outside of string with malformed UTF-8 in unpack
+
+(F) You had a template that specified an absolute position outside
+the string being unpacked. The string being unpacked was also invalid
+UTF-8. See L<perlfunc/pack>.
+
+=item %s package attribute may clash with future reserved word: %s
+
+(W reserved) A lowercase attribute name was used that had a
+package-specific handler. That name might have a meaning to Perl itself
+some day, even though it doesn't yet. Perhaps you should use a
+mixed-case attribute name, instead. See L<attributes>.
+
+=item pack/unpack repeat count overflow
+
+(F) You can't specify a repeat count so large that it overflows your
+signed integers. See L<perlfunc/pack>.
+
+=item page overflow
+
+(W io) A single call to write() produced more lines than can fit on a
+page. See L<perlform>.
+
+=item panic: %s
+
+(P) An internal error.
+
+=item panic: attempt to call %s in %s
+
+(P) One of the file test operators entered a code branch that calls
+an ACL related-function, but that function is not available on this
+platform. Earlier checks mean that it should not be possible to
+enter this branch on this platform.
+
+=item panic: ck_grep
+
+(P) Failed an internal consistency check trying to compile a grep.
+
+=item panic: ck_split
+
+(P) Failed an internal consistency check trying to compile a split.
+
+=item panic: corrupt saved stack index
+
+(P) The savestack was requested to restore more localized values than
+there are in the savestack.
+
+=item panic: del_backref
+
+(P) Failed an internal consistency check while trying to reset a weak
+reference.
+
+=item panic: Devel::DProf inconsistent subroutine return
+
+(P) Devel::DProf called a subroutine that exited using goto(LABEL),
+last(LABEL) or next(LABEL). Leaving that way a subroutine called from
+an XSUB will lead very probably to a crash of the interpreter. This is
+a bug that will hopefully one day get fixed.
+
+=item panic: die %s
+
+(P) We popped the context stack to an eval context, and then discovered
+it wasn't an eval context.
+
+=item panic: do_subst
+
+(P) The internal pp_subst() routine was called with invalid operational
+data.
+
+=item panic: do_trans_%s
+
+(P) The internal do_trans routines were called with invalid operational
+data.
+
+=item panic: fold_constants JMPENV_PUSH returned %d
+
+(P) While attempting folding constants an exception other than an C<eval>
+failure was caught.
+
+=item panic: frexp
+
+(P) The library function frexp() failed, making printf("%f") impossible.
+
+=item panic: goto
+
+(P) We popped the context stack to a context with the specified label,
+and then discovered it wasn't a context we know how to do a goto in.
+
+=item panic: hfreeentries failed to free hash
+
+(P) The internal routine used to clear a hashes entries tried repeatedly,
+but each time something added more entries to the hash. Most likely the hash
+contains an object with a reference back to the hash and a destructor that
+adds a new object to the hash.
+
+=item panic: INTERPCASEMOD
+
+(P) The lexer got into a bad state at a case modifier.
+
+=item panic: INTERPCONCAT
+
+(P) The lexer got into a bad state parsing a string with brackets.
+
+=item panic: kid popen errno read
+
+(F) forked child returned an incomprehensible message about its errno.
+
+=item panic: last
+
+(P) We popped the context stack to a block context, and then discovered
+it wasn't a block context.
+
+=item panic: leave_scope clearsv
+
+(P) A writable lexical variable became read-only somehow within the
+scope.
+
+=item panic: leave_scope inconsistency
+
+(P) The savestack probably got out of sync. At least, there was an
+invalid enum on the top of it.
+
+=item panic: magic_killbackrefs
+
+(P) Failed an internal consistency check while trying to reset all weak
+references to an object.
+
+=item panic: malloc
+
+(P) Something requested a negative number of bytes of malloc.
+
+=item panic: memory wrap
+
+(P) Something tried to allocate more memory than possible.
+
+=item panic: pad_alloc
+
+(P) The compiler got confused about which scratch pad it was allocating
+and freeing temporaries and lexicals from.
+
+=item panic: pad_free curpad
+
+(P) The compiler got confused about which scratch pad it was allocating
+and freeing temporaries and lexicals from.
+
+=item panic: pad_free po
+
+(P) An invalid scratch pad offset was detected internally.
+
+=item panic: pad_reset curpad
+
+(P) The compiler got confused about which scratch pad it was allocating
+and freeing temporaries and lexicals from.
+
+=item panic: pad_sv po
+
+(P) An invalid scratch pad offset was detected internally.
+
+=item panic: pad_swipe curpad
+
+(P) The compiler got confused about which scratch pad it was allocating
+and freeing temporaries and lexicals from.
+
+=item panic: pad_swipe po
+
+(P) An invalid scratch pad offset was detected internally.
+
+=item panic: pp_iter
+
+(P) The foreach iterator got called in a non-loop context frame.
+
+=item panic: pp_match%s
+
+(P) The internal pp_match() routine was called with invalid operational
+data.
+
+=item panic: pp_split
+
+(P) Something terrible went wrong in setting up for the split.
+
+=item panic: realloc
+
+(P) Something requested a negative number of bytes of realloc.
+
+=item panic: restartop
+
+(P) Some internal routine requested a goto (or something like it), and
+didn't supply the destination.
+
+=item panic: return
+
+(P) We popped the context stack to a subroutine or eval context, and
+then discovered it wasn't a subroutine or eval context.
+
+=item panic: scan_num
+
+(P) scan_num() got called on something that wasn't a number.
+
+=item panic: sv_chop %s
+
+(P) The sv_chop() routine was passed a position that is not within the
+scalar's string buffer.
+
+=item panic: sv_insert
+
+(P) The sv_insert() routine was told to remove more string than there
+was string.
+
+=item panic: top_env
+
+(P) The compiler attempted to do a goto, or something weird like that.
+
+=item panic: unimplemented op %s (#%d) called
+
+(P) The compiler is screwed up and attempted to use an op that isn't permitted
+at run time.
+
+=item panic: utf16_to_utf8: odd bytelen
+
+(P) Something tried to call utf16_to_utf8 with an odd (as opposed
+to even) byte length.
+
+=item panic: yylex
+
+(P) The lexer got into a bad state while processing a case modifier.
+
+=item Pattern subroutine nesting without pos change exceeded limit in regex; marked by <-- HERE in m/%s/
+
+(F) You used a pattern that uses too many nested subpattern calls without
+consuming any text. Restructure the pattern so text is consumed before the
+nesting limit is exceeded.
+
+The <-- HERE shows in the regular expression about where the problem was
+discovered.
+
+=item Parentheses missing around "%s" list
+
+(W parenthesis) You said something like
+
+ my $foo, $bar = @_;
+
+when you meant
+
+ my ($foo, $bar) = @_;
+
+Remember that "my", "our", "local" and "state" bind tighter than comma.
+
+=item C<-p> destination: %s
+
+(F) An error occurred during the implicit output invoked by the C<-p>
+command-line switch. (This output goes to STDOUT unless you've
+redirected it with select().)
+
+=item (perhaps you forgot to load "%s"?)
+
+(F) This is an educated guess made in conjunction with the message
+"Can't locate object method \"%s\" via package \"%s\"". It often means
+that a method requires a package that has not been loaded.
+
+=item Perl_my_%s() not available
+
+(F) Your platform has very uncommon byte-order and integer size,
+so it was not possible to set up some or all fixed-width byte-order
+conversion functions. This is only a problem when you're using the
+'<' or '>' modifiers in (un)pack templates. See L<perlfunc/pack>.
+
+=item Perl %s required--this is only version %s, stopped
+
+(F) The module in question uses features of a version of Perl more
+recent than the currently running version. How long has it been since
+you upgraded, anyway? See L<perlfunc/require>.
+
+=item PERL_SH_DIR too long
+
+(F) An error peculiar to OS/2. PERL_SH_DIR is the directory to find the
+C<sh>-shell in. See "PERL_SH_DIR" in L<perlos2>.
+
+=item PERL_SIGNALS illegal: "%s"
+
+See L<perlrun/PERL_SIGNALS> for legal values.
+
+=item perl: warning: Setting locale failed.
+
+(S) The whole warning message will look something like:
+
+ perl: warning: Setting locale failed.
+ perl: warning: Please check that your locale settings:
+ LC_ALL = "En_US",
+ LANG = (unset)
+ are supported and installed on your system.
+ perl: warning: Falling back to the standard locale ("C").
+
+Exactly what were the failed locale settings varies. In the above the
+settings were that the LC_ALL was "En_US" and the LANG had no value.
+This error means that Perl detected that you and/or your operating
+system supplier and/or system administrator have set up the so-called
+locale system but Perl could not use those settings. This was not
+dead serious, fortunately: there is a "default locale" called "C" that
+Perl can and will use, the script will be run. Before you really fix
+the problem, however, you will get the same error message each time
+you run Perl. How to really fix the problem can be found in
+L<perllocale> section B<LOCALE PROBLEMS>.
+
+=item Permission denied
+
+(F) The setuid emulator in suidperl decided you were up to no good.
+
+=item pid %x not a child
+
+(W exec) A warning peculiar to VMS. Waitpid() was asked to wait for a
+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 in unpack
+
+(F) The unpack format P must have an explicit size, not "*".
+
+=item B<-P> not allowed for setuid/setgid script
+
+(F) The script would have to be opened by the C preprocessor by name,
+which provides a race condition that breaks security.
+
+=item POSIX class [:%s:] unknown in regex; marked by <-- HERE in m/%s/
+
+(F) The class in the character class [: :] syntax is unknown. The <-- HERE
+shows in the regular expression about where the problem was discovered.
+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
+
+(F) Your system has POSIX getpgrp(), which takes no argument, unlike
+the BSD version, which takes a pid.
+
+=item POSIX syntax [%s] belongs inside character classes in regex; marked by <-- HERE in m/%s/
+
+(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
+cause fatal errors. The <-- HERE shows in the regular expression about
+where the problem was discovered. See L<perlre>.
+
+=item POSIX syntax [. .] is reserved for future extensions in regex; marked by <-- HERE in m/%s/
+
+(F regexp) Within regular expression character classes ([]) the syntax
+beginning with "[." and ending with ".]" is reserved for future extensions.
+If you need to represent those character sequences inside a regular
+expression character class, just quote the square brackets with the
+backslash: "\[." and ".\]". The <-- HERE shows in the regular expression
+about where the problem was discovered. See L<perlre>.
+
+=item POSIX syntax [= =] is reserved for future extensions in regex; marked by <-- HERE in m/%s/
+
+(F) Within regular expression character classes ([]) the syntax beginning
+with "[=" and ending with "=]" is reserved for future extensions. If you
+need to represent those character sequences inside a regular expression
+character class, just quote the square brackets with the backslash: "\[="
+and "=\]". The <-- HERE shows in the regular expression about where the
+problem was discovered. See L<perlre>.
+
+=item Possible attempt to put comments in qw() list
+
+(W qw) qw() lists contain items separated by whitespace; as with literal
+strings, comment characters are not ignored, but are instead treated as
+literal data. (You may have used different delimiters than the
+parentheses shown here; braces are also frequently used.)
+
+You probably wrote something like this:
+
+ @list = qw(
+ a # a comment
+ b # another comment
+ );
+
+when you should have written this:
+
+ @list = qw(
+ a
+ b
+ );
+
+If you really want comments, build your list the
+old-fashioned way, with quotes and commas:
+
+ @list = (
+ 'a', # a comment
+ 'b', # another comment
+ );
+
+=item Possible attempt to separate words with commas
+
+(W qw) qw() lists contain items separated by whitespace; therefore
+commas aren't needed to separate the items. (You may have used
+different delimiters than the parentheses shown here; braces are also
+frequently used.)
+
+You probably wrote something like this:
+
+ qw! a, b, c !;
+
+which puts literal commas into some of the list items. Write it without
+commas if you don't want them to appear in your data:
+
+ qw! a b c !;
+
+=item Possible memory corruption: %s overflowed 3rd argument
+
+(F) An ioctl() or fcntl() returned more than Perl was bargaining for.
+Perl guesses a reasonable buffer size, but puts a sentinel byte at the
+end of the buffer just in case. This sentinel byte got clobbered, and
+Perl assumes that memory is now corrupted. See L<perlfunc/ioctl>.
+
+=item Possible precedence problem on bitwise %c operator
+
+(W precedence) Your program uses a bitwise logical operator in conjunction
+with a numeric comparison operator, like this :
+
+ if ($x & $y == 0) { ... }
+
+This expression is actually equivalent to C<$x & ($y == 0)>, due to the
+higher precedence of C<==>. This is probably not what you want. (If you
+really meant to write this, disable the warning, or, better, put the
+parentheses explicitly and write C<$x & ($y == 0)>).
+
+=item Possible unintended interpolation of %s in string
+
+(W ambiguous) You said something like `@foo' in a double-quoted string
+but there was no array C<@foo> in scope at the time. If you wanted a
+literal @foo, then write it as \@foo; otherwise find out what happened
+to the array you apparently lost track of.
+
+=item pragma "attrs" is deprecated, use "sub NAME : ATTRS" instead
+
+(D deprecated) You have written something like this:
+
+ sub doit
+ {
+ use attrs qw(locked);
+ }
+
+You should use the new declaration syntax instead.
+
+ sub doit : locked
+ {
+ ...
+
+The C<use attrs> pragma is now obsolete, and is only provided for
+backward-compatibility. See L<perlsub/"Subroutine Attributes">.
+
+=item Precedence problem: open %s should be open(%s)
+
+(S precedence) The old irregular construct
+
+ open FOO || die;
+
+is now misinterpreted as
+
+ open(FOO || die);
+
+because of the strict regularization of Perl 5's grammar into unary and
+list operators. (The old open was a little of both.) You must put
+parentheses around the filehandle, or use the new "or" operator instead
+of "||".
+
+=item Premature end of script headers
+
+See Server error.
+
+=item printf() on closed filehandle %s
+
+(W closed) The filehandle you're writing to got itself closed sometime
+before now. Check your control flow.
+
+=item print() on closed filehandle %s
+
+(W closed) The filehandle you're printing on got itself closed sometime
+before now. Check your control flow.
+
+=item Process terminated by SIG%s
+
+(W) This is a standard message issued by OS/2 applications, while *nix
+applications die in silence. It is considered a feature of the OS/2
+port. One can easily disable this by appropriate sighandlers, see
+L<perlipc/"Signals">. See also "Process terminated by SIGTERM/SIGINT"
+in L<perlos2>.
+
+=item Prototype mismatch: %s vs %s
+
+(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 follows nothing in regex; marked by <-- HERE in m/%s/
+
+(F) You started a regular expression with a quantifier. Backslash it if you
+meant it literally. The <-- HERE shows in the regular expression about
+where the problem was discovered. See L<perlre>.
+
+=item Quantifier in {,} bigger than %d in regex; marked by <-- HERE in m/%s/
+
+(F) There is currently a limit to the size of the min and max values of the
+{min,max} construct. The <-- HERE shows in the regular expression about where
+the problem was discovered. See L<perlre>.
+
+=item Quantifier unexpected on zero-length expression; marked by <-- HERE in m/%s/
+
+(W regexp) You applied a regular expression quantifier in a place where
+it makes no sense, such as on a zero-width assertion. Try putting the
+quantifier inside the assertion instead. For example, the way to match
+"abc" provided that it is followed by three repetitions of "xyz" is
+C</abc(?=(?:xyz){3})/>, not C</abc(?=xyz){3}/>.
+
+The <-- HERE shows in the regular expression about where the problem was
+discovered.
+
+=item Range iterator outside integer range
+
+(F) One (or both) of the numeric arguments to the range operator ".."
+are outside the range which can be represented by integers internally.
+One possible workaround is to force Perl to use magical string increment
+by prepending "0" to your numbers.
+
+=item readdir() attempted on invalid dirhandle %s
+
+(W io) The dirhandle you're reading from is either closed or not really
+a dirhandle. Check your control flow.
+
+=item readline() on closed filehandle %s
+
+(W closed) The filehandle you're reading from got itself closed sometime
+before now. Check your control flow.
+
+=item read() on closed filehandle %s
+
+(W closed) You tried to read from a closed filehandle.
+
+=item read() on unopened filehandle %s
+
+(W unopened) You tried to read from a filehandle that was never opened.
+
+=item Reallocation too large: %lx
+
+(F) You can't allocate more than 64K on an MS-DOS machine.
+
+=item realloc() of freed memory ignored
+
+(S malloc) An internal routine called realloc() on something that had
+already been freed.
+
+=item Recompile perl with B<-D>DEBUGGING to use B<-D> switch
+
+(F debugging) You can't use the B<-D> option unless the code to produce
+the desired output is compiled into Perl, which entails some overhead,
+which is why it's currently left out of your copy.
+
+=item Recursive inheritance detected in package '%s'
+
+(F) While calculating the method resolution order (MRO) of a package, Perl
+believes it found an infinite loop in the C<@ISA> hierarchy. This is a
+crude check that bails out after 100 levels of C<@ISA> depth.
+
+=item Recursive inheritance detected while looking for method %s
+
+(F) More than 100 levels of inheritance were encountered while invoking
+a method. Probably indicates an unintended loop in your inheritance
+hierarchy.
+
+=item Reference found where even-sized list expected
+
+(W misc) You gave a single reference where Perl was expecting a list
+with an even number of elements (for assignment to a hash). This usually
+means that you used the anon hash constructor when you meant to use
+parens. In any case, a hash requires key/value B<pairs>.
+
+ %hash = { one => 1, two => 2, }; # WRONG
+ %hash = [ qw/ an anon array / ]; # WRONG
+ %hash = ( one => 1, two => 2, ); # right
+ %hash = qw( one 1 two 2 ); # also fine
+
+=item Reference is already weak
+
+(W misc) You have attempted to weaken a reference that is already weak.
+Doing so has no effect.
+
+=item Reference miscount in sv_replace()
+
+(W internal) The internal sv_replace() function was handed a new SV with
+a reference count of other than 1.
+
+=item Reference to invalid group 0
+
+(F) You used C<\g0> or similar in a regular expression. You may refer to
+capturing parentheses only with strictly positive integers (normal
+backreferences) or with strictly negative integers (relative
+backreferences), but using 0 does not make sense.
+
+=item Reference to nonexistent group in regex; marked by <-- HERE in m/%s/
+
+(F) You used something like C<\7> in your regular expression, but there are
+not at least seven sets of capturing parentheses in the expression. If you
+wanted to have the character with value 7 inserted into the regular expression,
+prepend a zero to make the number at least two digits: C<\07>
+
+The <-- HERE shows in the regular expression about where the problem was
+discovered.
+
+=item Reference to nonexistent or unclosed group in regex; marked by <-- HERE in m/%s/
+
+(F) You used something like C<\g{-7}> in your regular expression, but there are
+not at least seven sets of closed capturing parentheses in the expression before
+where the C<\g{-7}> was located.
+
+The <-- HERE shows in the regular expression about where the problem was
+discovered.
+
+=item Reference to nonexistent named group in regex; marked by <-- HERE in m/%s/
+
+(F) You used something like C<\k'NAME'> or C<< \k<NAME> >> in your regular
+expression, but there is no corresponding named capturing parentheses such
+as C<(?'NAME'...)> or C<(?<NAME>...). Check if the name has been spelled
+correctly both in the backreference and the declaration.
+
+The <-- HERE shows in the regular expression about where the problem was
+discovered.
+
+=item (?(DEFINE)....) does not allow branches in regex; marked by <-- HERE in m/%s/
+
+(F) You used something like C<(?(DEFINE)...|..)> which is illegal. The
+most likely cause of this error is that you left out a parenthesis inside
+of the C<....> part.
+
+The <-- HERE shows in the regular expression about where the problem was
+discovered.
+
+=item regexp memory corruption
+
+(P) The regular expression engine got confused by what the regular
+expression compiler gave it.
+
+=item Regexp out of space
+
+(P) A "can't happen" error, because safemalloc() should have caught it
+earlier.
+
+=item Repeated format line will never terminate (~~ and @# incompatible)
+
+(F) Your format contains the ~~ repeat-until-blank sequence and a
+numeric field that will never go blank so that the repetition never
+terminates. You might use ^# instead. See L<perlform>.
+
+=item Reversed %s= operator
+
+(W syntax) You wrote your assignment operator backwards. The = must
+always comes last, to avoid ambiguity with subsequent unary operators.
+
+=item rewinddir() attempted on invalid dirhandle %s
+
+(W io) The dirhandle you tried to do a rewinddir() on is either closed or not
+really a dirhandle. Check your control flow.
+
+=item Runaway format
+
+(F) Your format contained the ~~ repeat-until-blank sequence, but it
+produced 200 lines at once, and the 200th line looked exactly like the
+199th line. Apparently you didn't arrange for the arguments to exhaust
+themselves, either by using ^ instead of @ (for scalar variables), or by
+shifting or popping (for array variables). See L<perlform>.
+
+=item Scalars leaked: %d
+
+(P) Something went wrong in Perl's internal bookkeeping of scalars:
+not all scalar variables were deallocated by the time Perl exited.
+What this usually indicates is a memory leak, which is of course bad,
+especially if the Perl program is intended to be long-running.
+
+=item Scalar value @%s[%s] better written as $%s[%s]
+
+(W syntax) You've used an array slice (indicated by @) to select a
+single element of an array. Generally it's better to ask for a scalar
+value (indicated by $). The difference is that C<$foo[&bar]> always
+behaves like a scalar, both when assigning to it and when evaluating its
+argument, while C<@foo[&bar]> behaves like a list when you assign to it,
+and provides a list context to its subscript, which can do weird things
+if you're expecting only one subscript.
+
+On the other hand, if you were actually hoping to treat the array
+element as a list, you need to look into how references work, because
+Perl will not magically convert between scalars and lists for you. See
+L<perlref>.
+
+=item Scalar value @%s{%s} better written as $%s{%s}
+
+(W syntax) You've used a hash slice (indicated by @) to select a single
+element of a hash. Generally it's better to ask for a scalar value
+(indicated by $). The difference is that C<$foo{&bar}> always behaves
+like a scalar, both when assigning to it and when evaluating its
+argument, while C<@foo{&bar}> behaves like a list when you assign to it,
+and provides a list context to its subscript, which can do weird things
+if you're expecting only one subscript.
+
+On the other hand, if you were actually hoping to treat the hash element
+as a list, you need to look into how references work, because Perl will
+not magically convert between scalars and lists for you. See
+L<perlref>.
+
+=item Script is not setuid/setgid in suidperl
+
+(F) Oddly, the suidperl program was invoked on a script without a setuid
+or setgid bit set. This doesn't make much sense.
+
+=item Search pattern not terminated
+
+(F) The lexer couldn't find the final delimiter of a // or m{}
+construct. Remember that bracketing delimiters count nesting level.
+Missing the leading C<$> from a variable C<$m> may cause this error.
+
+Note that since Perl 5.9.0 a // can also be the I<defined-or>
+construct, not just the empty search pattern. Therefore code written
+in Perl 5.9.0 or later that uses the // as the I<defined-or> can be
+misparsed by pre-5.9.0 Perls as a non-terminated search pattern.
+
+=item Search pattern not terminated or ternary operator parsed as search pattern
+
+(F) The lexer couldn't find the final delimiter of a C<?PATTERN?>
+construct.
+
+The question mark is also used as part of the ternary operator (as in
+C<foo ? 0 : 1>) leading to some ambiguous constructions being wrongly
+parsed. One way to disambiguate the parsing is to put parentheses around
+the conditional expression, i.e. C<(foo) ? 0 : 1>.
+
+=item %sseek() on unopened filehandle
+
+(W unopened) You tried to use the seek() or sysseek() function on a
+filehandle that was either never opened or has since been closed.
+
+=item seekdir() attempted on invalid dirhandle %s
+
+(W io) The dirhandle you are doing a seekdir() on is either closed or not
+really a dirhandle. Check your control flow.
+
+=item select not implemented
+
+(F) This machine doesn't implement the select() system call.
+
+=item Self-ties of arrays and hashes are not supported
+
+(F) Self-ties are of arrays and hashes are not supported in
+the current implementation.
+
+=item Semicolon seems to be missing
+
+(W semicolon) A nearby syntax error was probably caused by a missing
+semicolon, or possibly some other missing operator, such as a comma.
+
+=item semi-panic: attempt to dup freed string
+
+(S internal) The internal newSVsv() routine was called to duplicate a
+scalar that had previously been marked as free.
+
+=item sem%s not implemented
+
+(F) You don't have System V semaphore IPC on your system.
+
+=item send() on closed socket %s
+
+(W closed) The socket you're sending to got itself closed sometime
+before now. Check your control flow.
+
+=item Sequence (? incomplete in regex; marked by <-- HERE in m/%s/
+
+(F) A regular expression ended with an incomplete extension (?. The <-- HERE
+shows in the regular expression about where the problem was discovered. See
+L<perlre>.
+
+=item Sequence (?%s...) not implemented in regex; marked by <-- HERE in m/%s/
+
+(F) A proposed regular expression extension has the character reserved but
+has not yet been written. The <-- HERE shows in the regular expression about
+where the problem was discovered. See L<perlre>.
+
+=item Sequence (?%s...) not recognized in regex; marked by <-- HERE in m/%s/
+
+(F) You used a regular expression extension that doesn't make sense. The
+<-- HERE shows in the regular expression about where the problem was
+discovered. See L<perlre>.
+
+=item Sequence \\%s... not terminated in regex; marked by <-- HERE in m/%s/
+
+(F) The regular expression expects a mandatory argument following the escape
+sequence and this has been omitted or incorrectly written.
+
+=item Sequence (?#... not terminated in regex; marked by <-- HERE in m/%s/
+
+(F) A regular expression comment must be terminated by a closing
+parenthesis. Embedded parentheses aren't allowed. The <-- HERE shows in
+the regular expression about where the problem was discovered. See
+L<perlre>.
+
+=item Sequence (?{...}) not terminated or not {}-balanced in regex; marked by <-- HERE in m/%s/
+
+(F) If the contents of a (?{...}) clause contains braces, they must balance
+for Perl to properly detect the end of the clause. The <-- HERE shows in
+the regular expression about where the problem was discovered. See
+L<perlre>.
+
+=item 500 Server error
+
+See Server error.
+
+=item Server error
+
+This is the error message generally seen in a browser window when trying
+to run a CGI program (including SSI) over the web. The actual error text
+varies widely from server to server. The most frequently-seen variants
+are "500 Server error", "Method (something) not permitted", "Document
+contains no data", "Premature end of script headers", and "Did not
+produce a valid header".
+
+B<This is a CGI error, not a Perl error>.
+
+You need to make sure your script is executable, is accessible by the
+user CGI is running the script under (which is probably not the user
+account you tested it under), does not rely on any environment variables
+(like PATH) from the user it isn't running under, and isn't in a
+location where the CGI server can't find it, basically, more or less.
+Please see the following for more information:
+
+ 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>.
+
+=item setegid() not implemented
+
+(F) You tried to assign to C<$)>, and your operating system doesn't
+support the setegid() system call (or equivalent), or at least Configure
+didn't think so.
+
+=item seteuid() not implemented
+
+(F) You tried to assign to C<< $> >>, and your operating system doesn't
+support the seteuid() system call (or equivalent), or at least Configure
+didn't think so.
+
+=item setpgrp can't take arguments
+
+(F) Your system has the setpgrp() from BSD 4.2, which takes no
+arguments, unlike POSIX setpgid(), which takes a process ID and process
+group ID.
+
+=item setrgid() not implemented
+
+(F) You tried to assign to C<$(>, and your operating system doesn't
+support the setrgid() system call (or equivalent), or at least Configure
+didn't think so.
+
+=item setruid() not implemented
+
+(F) You tried to assign to C<$<>, and your operating system doesn't
+support the setruid() system call (or equivalent), or at least Configure
+didn't think so.
+
+=item setsockopt() on closed socket %s
+
+(W closed) You tried to set a socket option on a closed socket. Did you
+forget to check the return value of your socket() call? See
+L<perlfunc/setsockopt>.
+
+=item Setuid/gid script is writable by world
+
+(F) The setuid emulator won't run a script that is writable by the
+world, because the world might have written on it already.
+
+=item Setuid script not plain file
+
+(F) The setuid emulator won't run a script that isn't read from a file,
+but from a socket, a pipe or another device.
+
+=item shm%s not implemented
+
+(F) You don't have System V shared memory IPC on your system.
+
+=item !=~ should be !~
+
+(W syntax) The non-matching operator is !~, not !=~. !=~ will be
+interpreted as the != (numeric not equal) and ~ (1's complement)
+operators: probably not what you intended.
+
+=item <> should be quotes
+
+(F) You wrote C<< require <file> >> when you should have written
+C<require 'file'>.
+
+=item /%s/ should probably be written as "%s"
+
+(W syntax) You have used a pattern where Perl expected to find a string,
+as in the first argument to C<join>. Perl will treat the true or false
+result of matching the pattern against $_ as the string, which is
+probably not what you had in mind.
+
+=item shutdown() on closed socket %s
+
+(W closed) You tried to do a shutdown on a closed socket. Seems a bit
+superfluous.
+
+=item SIG%s handler "%s" not defined
+
+(W signal) The signal handler named in %SIG doesn't, in fact, exist.
+Perhaps you put it into the wrong package?
+
+=item Smart matching a non-overloaded object breaks encapsulation
+
+(F) You should not use the C<~~> operator on an object that does not
+overload it: Perl refuses to use the object's underlying structure for
+the smart match.
+
+=item sort is now a reserved word
+
+(F) An ancient error message that almost nobody ever runs into anymore.
+But before sort was a keyword, people sometimes used it as a filehandle.
+
+=item Sort subroutine didn't return a numeric value
+
+(F) A sort comparison routine must return a number. You probably blew
+it by not using C<< <=> >> or C<cmp>, or by not using them correctly.
+See L<perlfunc/sort>.
+
+=item Sort subroutine didn't return single value
+
+(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 = $offset. See
+L<perlfunc/splice>.
+
+=item Split loop
+
+(P) The split was looping infinitely. (Obviously, a split shouldn't
+iterate more times than there are characters of input, which is what
+happened.) See L<perlfunc/split>.
+
+=item Statement unlikely to be reached
+
+(W exec) You did an exec() with some statement after it other than a
+die(). This is almost always an error, because exec() never returns
+unless there was a failure. You probably wanted to use system()
+instead, which does return. To suppress this warning, put the exec() in
+a block by itself.
+
+=item stat() on unopened filehandle %s
+
+(W unopened) You tried to use the stat() function on a filehandle that
+was either never opened or has since been closed.
+
+=item Stub found while resolving method "%s" overloading "%s"
+
+(P) Overloading resolution over @ISA tree may be broken by importation
+stubs. Stubs should never be implicitly created, but explicit calls to
+C<can> may break this.
+
+=item Subroutine %s redefined
+
+(W redefine) You redefined a subroutine. To suppress this warning, say
+
+ {
+ no warnings 'redefine';
+ eval "sub name { ... }";
+ }
+
+=item Substitution loop
+
+(P) The substitution was looping infinitely. (Obviously, a substitution
+shouldn't iterate more times than there are characters of input, which
+is what happened.) See the discussion of substitution in
+L<perlop/"Regexp Quote-Like Operators">.
+
+=item Substitution pattern not terminated
+
+(F) The lexer couldn't find the interior delimiter of an s/// or s{}{}
+construct. Remember that bracketing delimiters count nesting level.
+Missing the leading C<$> from variable C<$s> may cause this error.
+
+=item Substitution replacement not terminated
+
+(F) The lexer couldn't find the final delimiter of an s/// or s{}{}
+construct. Remember that bracketing delimiters count nesting level.
+Missing the leading C<$> from variable C<$s> may cause this error.
+
+=item substr outside of string
+
+(W substr),(F) You tried to reference a substr() that pointed outside of
+a string. That is, the absolute value of the offset was larger than the
+length of the string. See L<perlfunc/substr>. This warning is fatal if
+substr is used in an lvalue context (as the left hand side of an
+assignment or as a subroutine argument for example).
+
+=item suidperl is no longer needed since %s
+
+(F) Your Perl was compiled with B<-D>SETUID_SCRIPTS_ARE_SECURE_NOW, but
+a version of the setuid emulator somehow got run anyway.
+
+=item sv_upgrade from type %d down to type %d
+
+(P) Perl tried to force the upgrade an SV to a type which was actually
+inferior to its current type.
+
+=item Switch (?(condition)... contains too many branches in regex; marked by <-- HERE in m/%s/
+
+(F) A (?(condition)if-clause|else-clause) construct can have at most two
+branches (the if-clause and the else-clause). If you want one or both to
+contain alternation, such as using C<this|that|other>, enclose it in
+clustering parentheses:
+
+ (?(condition)(?:this|that|other)|else-clause)
+
+The <-- HERE shows in the regular expression about where the problem was
+discovered. See L<perlre>.
+
+=item Switch condition not recognized in regex; marked by <-- HERE in m/%s/
+
+(F) If the argument to the (?(...)if-clause|else-clause) construct is a
+number, it can be only a number. The <-- HERE shows in the regular expression
+about where the problem was discovered. See L<perlre>.
+
+=item switching effective %s is not implemented
+
+(F) While under the C<use filetest> pragma, we cannot switch the real
+and effective uids or gids.
+
+=item %s syntax
+
+(F) The final summary message when a C<perl -c> succeeds.
+
+=item syntax error
+
+(F) Probably means you had a syntax error. Common reasons include:
+
+ A keyword is misspelled.
+ A semicolon is missing.
+ A comma is missing.
+ An opening or closing parenthesis is missing.
+ An opening or closing brace is missing.
+ A closing quote is missing.
+
+Often there will be another error message associated with the syntax
+error giving more information. (Sometimes it helps to turn on B<-w>.)
+The error message itself often tells you where it was in the line when
+it decided to give up. Sometimes the actual error is several tokens
+before this, because Perl is good at understanding random input.
+Occasionally the line number may be misleading, and once in a blue moon
+the only way to figure out what's triggering the error is to call
+C<perl -c> repeatedly, chopping away half the program each time to see
+if the error went away. Sort of the cybernetic version of S<20
+questions>.
+
+=item syntax error at line %d: `%s' unexpected
+
+(A) You've accidentally run your script through the Bourne shell instead
+of Perl. Check the #! line, or manually feed your script into Perl
+yourself.
+
+=item syntax error in file %s at line %d, next 2 tokens "%s"
+
+(F) This error is likely to occur if you run a perl5 script through
+a perl4 interpreter, especially if the next 2 tokens are "use strict"
+or "my $var" or "our $var".
+
+=item sysread() on closed filehandle %s
+
+(W closed) You tried to read from a closed filehandle.
+
+=item sysread() on unopened filehandle %s
+
+(W unopened) You tried to read from a filehandle that was never opened.
+
+=item System V %s is not implemented on this machine
+
+(F) You tried to do something with a function beginning with "sem",
+"shm", or "msg" but that System V IPC is not implemented in your
+machine. In some machines the functionality can exist but be
+unconfigured. Consult your system support.
+
+=item syswrite() on closed filehandle %s
+
+(W closed) The filehandle you're writing to got itself closed sometime
+before now. Check your control flow.
+
+=item C<-T> and C<-B> not implemented on filehandles
+
+(F) Perl can't peek at the stdio buffer of filehandles when it doesn't
+know about your kind of stdio. You'll have to use a filename instead.
+
+=item Target of goto is too deeply nested
+
+(F) You tried to use C<goto> to reach a label that was too deeply nested
+for Perl to reach. Perl is doing you a favor by refusing.
+
+=item tell() on unopened filehandle
+
+(W unopened) You tried to use the tell() function on a filehandle that
+was either never opened or has since been closed.
+
+=item telldir() attempted on invalid dirhandle %s
+
+(W io) The dirhandle you tried to telldir() is either closed or not really
+a dirhandle. Check your control flow.
+
+=item That use of $[ is unsupported
+
+(F) Assignment to C<$[> is now strictly circumscribed, and interpreted
+as a compiler directive. You may say only one of
+
+ $[ = 0;
+ $[ = 1;
+ ...
+ local $[ = 0;
+ local $[ = 1;
+ ...
+
+This is to prevent the problem of one module changing the array base out
+from under another module inadvertently. See L<perlvar/$[>.
+
+=item The crypt() function is unimplemented due to excessive paranoia
+
+(F) Configure couldn't find the crypt() function on your machine,
+probably because your vendor didn't supply it, probably because they
+think the U.S. Government thinks it's a secret, or at least that they
+will continue to pretend that it is. And if you quote me on that, I
+will deny it.
+
+=item The %s function is unimplemented
+
+The function indicated isn't implemented on this architecture, according
+to the probings of Configure.
+
+=item The stat preceding %s wasn't an lstat
+
+(F) It makes no sense to test the current stat buffer for symbolic
+linkhood if the last stat that wrote to the stat buffer already went
+past the symlink to get to the real file. Use an actual filename
+instead.
+
+=item The 'unique' attribute may only be applied to 'our' variables
+
+(F) This attribute was never supported on C<my> or C<sub> declarations.
+
+=item This Perl can't reset CRTL environ elements (%s)
+
+=item This Perl can't set CRTL environ elements (%s=%s)
+
+(W internal) Warnings peculiar to VMS. You tried to change or delete an
+element of the CRTL's internal environ array, but your copy of Perl
+wasn't built with a CRTL that contained the setenv() function. You'll
+need to rebuild Perl with a CRTL that does, or redefine
+F<PERL_ENV_TABLES> (see L<perlvms>) so that the environ array isn't the
+target of the change to
+%ENV which produced the warning.
+
+=item thread failed to start: %s
+
+(W threads)(S) The entry point function of threads->create() failed for some reason.
+
+=item times not implemented
+
+(F) Your version of the C library apparently doesn't do times(). I
+suspect you're not running on Unix.
+
+=item "-T" is on the #! line, it must also be used on the command line
+
+(X) The #! line (or local equivalent) in a Perl script contains the
+B<-T> option, but Perl was not invoked with B<-T> in its command line.
+This is an error because, by the time Perl discovers a B<-T> in a
+script, it's too late to properly taint everything from the environment.
+So Perl gives up.
+
+If the Perl script is being executed as a command using the #!
+mechanism (or its local equivalent), this error can usually be fixed by
+editing the #! line so that the B<-T> option is a part of Perl's first
+argument: e.g. change C<perl -n -T> to C<perl -T -n>.
+
+If the Perl script is being executed as C<perl scriptname>, then the
+B<-T> option must appear on the command line: C<perl -T scriptname>.
+
+=item To%s: illegal mapping '%s'
+
+(F) You tried to define a customized To-mapping for lc(), lcfirst,
+uc(), or ucfirst() (or their string-inlined versions), but you
+specified an illegal mapping.
+See L<perlunicode/"User-Defined Character Properties">.
+
+=item Too deeply nested ()-groups
+
+(F) Your template contains ()-groups with a ridiculously deep nesting level.
+
+=item Too few args to syscall
+
+(F) There has to be at least one argument to syscall() to specify the
+system call to call, silly dilly.
+
+=item Too late for "-%s" option
+
+(X) The #! line (or local equivalent) in a Perl script contains the
+B<-M>, B<-m> or B<-C> option.
+
+In the case of B<-M> and B<-m>, this is an error because those options are
+not intended for use inside scripts. Use the C<use> pragma instead.
+
+The B<-C> option only works if it is specified on the command line as well
+(with the same sequence of letters or numbers following). Either specify
+this option on the command line, or, if your system supports it, make your
+script executable and run it directly instead of passing it to perl.
+
+=item Too late to run %s block
+
+(W void) A CHECK or INIT block is being defined during run time proper,
+when the opportunity to run them has already passed. Perhaps you are
+loading a file with C<require> or C<do> when you should be using C<use>
+instead. Or perhaps you should put the C<require> or C<do> inside a
+BEGIN block.
+
+=item Too many args to syscall
+
+(F) Perl supports a maximum of only 14 args to syscall().
+
+=item Too many arguments for %s
+
+(F) The function requires fewer arguments than you specified.
+
+=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
+
+(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 Trailing \ in regex m/%s/
+
+(F) The regular expression ends with an unbackslashed backslash.
+Backslash it. See L<perlre>.
+
+=item Transliteration pattern not terminated
+
+(F) The lexer couldn't find the interior delimiter of a tr/// or tr[][]
+or y/// or y[][] construct. Missing the leading C<$> from variables
+C<$tr> or C<$y> may cause this error.
+
+=item Transliteration replacement not terminated
+
+(F) The lexer couldn't find the final delimiter of a tr///, tr[][],
+y/// or y[][] construct.
+
+=item '%s' trapped by operation mask
+
+(F) You tried to use an operator from a Safe compartment in which it's
+disallowed. See L<Safe>.
+
+=item truncate not implemented
+
+(F) Your machine doesn't implement a file truncation mechanism that
+Configure knows about.
+
+=item Type of arg %d to %s must be %s (not %s)
+
+(F) This function requires the argument in that position to be of a
+certain type. Arrays must be @NAME or C<@{EXPR}>. Hashes must be
+%NAME or C<%{EXPR}>. No implicit dereferencing is allowed--use the
+{EXPR} forms as an explicit dereference. See L<perlref>.
+
+=item umask not implemented
+
+(F) Your machine doesn't implement the umask function and you tried to
+use it to restrict permissions for yourself (EXPR & 0700).
+
+=item Unable to create sub named "%s"
+
+(F) You attempted to create or access a subroutine with an illegal name.
+
+=item Unbalanced context: %d more PUSHes than POPs
+
+(W internal) The exit code detected an internal inconsistency in how
+many execution contexts were entered and left.
+
+=item Unbalanced saves: %d more saves than restores
+
+(W internal) The exit code detected an internal inconsistency in how
+many values were temporarily localized.
+
+=item Unbalanced scopes: %d more ENTERs than LEAVEs
+
+(W internal) The exit code detected an internal inconsistency in how
+many blocks were entered and left.
+
+=item Unbalanced tmps: %d more allocs than frees
+
+(W internal) The exit code detected an internal inconsistency in how
+many mortal scalars were allocated and freed.
+
+=item Undefined format "%s" called
+
+(F) The format indicated doesn't seem to exist. Perhaps it's really in
+another package? See L<perlform>.
+
+=item Undefined sort subroutine "%s" called
+
+(F) The sort comparison routine specified doesn't seem to exist.
+Perhaps it's in a different package? See L<perlfunc/sort>.
+
+=item Undefined subroutine &%s called
+
+(F) The subroutine indicated hasn't been defined, or if it was, it has
+since been undefined.
+
+=item Undefined subroutine called
+
+(F) The anonymous subroutine you're trying to call hasn't been defined,
+or if it was, it has since been undefined.
+
+=item Undefined subroutine in sort
+
+(F) The sort comparison routine specified is declared but doesn't seem
+to have been defined yet. See L<perlfunc/sort>.
+
+=item Undefined top format "%s" called
+
+(F) The format indicated doesn't seem to exist. Perhaps it's really in
+another package? See L<perlform>.
+
+=item Undefined value assigned to typeglob
+
+(W misc) An undefined value was assigned to a typeglob, a la
+C<*foo = undef>. This does nothing. It's possible that you really mean
+C<undef *foo>.
+
+=item %s: Undefined variable
+
+(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 unexec of %s into %s failed!
+
+(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
+
+(F) There are no byte-swapping functions for a machine with this byte
+order.
+
+=item Unknown open() mode '%s'
+
+(F) The second argument of 3-argument open() is not among the list
+of valid modes: C<< < >>, C<< > >>, C<<< >> >>>, C<< +< >>,
+C<< +> >>, C<<< +>> >>>, C<-|>, C<|->, C<< <& >>, C<< >& >>.
+
+=item Unknown PerlIO layer "%s"
+
+(W layer) An attempt was made to push an unknown layer onto the Perl I/O
+system. (Layers take care of transforming data between external and
+internal representations.) Note that some layers, such as C<mmap>,
+are not supported in all environments. If your program didn't
+explicitly request the failing operation, it may be the result of the
+value of the environment variable PERLIO.
+
+=item Unknown process %x sent message to prime_env_iter: %s
+
+(P) An error peculiar to VMS. Perl was reading values for %ENV before
+iterating over it, and someone else stuck a message in the stream of
+data Perl expected. Someone's very confused, or perhaps trying to
+subvert Perl's population of %ENV for nefarious purposes.
+
+=item Unknown "re" subpragma '%s' (known ones are: %s)
+
+You tried to use an unknown subpragma of the "re" pragma.
+
+=item Unknown switch condition (?(%.2s in regex; marked by <-- HERE in m/%s/
+
+(F) The condition part of a (?(condition)if-clause|else-clause) construct
+is not known. The condition may be lookahead or lookbehind (the condition
+is true if the lookahead or lookbehind is true), a (?{...}) construct (the
+condition is true if the code evaluates to a true value), or a number (the
+condition is true if the set of capturing parentheses named by the number
+matched).
+
+The <-- HERE shows in the regular expression about where the problem was
+discovered. See L<perlre>.
+
+=item Unknown Unicode option letter '%c'
+
+You specified an unknown Unicode option. See L<perlrun> documentation
+of the C<-C> switch for the list of known options.
+
+=item Unknown Unicode option value %x
+
+You specified an unknown Unicode option. See L<perlrun> documentation
+of the C<-C> switch for the list of known options.
+
+=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
+
+=item Unknown verb pattern '%s' in regex; marked by <-- HERE in m/%s/
+
+(F) You either made a typo or have incorrectly put a C<*> quantifier
+after an open brace in your pattern. Check the pattern and review
+L<perlre> for details on legal verb patterns.
+
+first.
+
+=item unmatched [ in regex; marked by <-- HERE in m/%s/
+
+(F) The brackets around a character class must match. If you wish to
+include a closing bracket in a character class, backslash it or put it
+first. The <-- HERE shows in the regular expression about where the problem
+was discovered. See L<perlre>.
+
+=item unmatched ( in regex; marked by <-- HERE in m/%s/
+
+(F) Unbackslashed parentheses must always be balanced in regular
+expressions. If you're a vi user, the % key is valuable for finding the
+matching parenthesis. The <-- HERE shows in the regular expression about
+where the problem was discovered. See L<perlre>.
+
+=item Unmatched right %s bracket
+
+(F) The lexer counted more closing curly or square brackets than opening
+ones, so you're probably missing a matching opening bracket. As a
+general rule, you'll find the missing one (so to speak) near the place
+you were last editing.
+
+=item Unquoted string "%s" may clash with future reserved word
+
+(W reserved) You used a bareword that might someday be claimed as a
+reserved word. It's best to put such a word in quotes, or capitalize it
+somehow, or insert an underbar into it. You might also declare it as a
+subroutine.
+
+=item Unrecognized character %s in column %d
+
+(F) The Perl parser has no idea what to do with the specified character
+in your Perl script (or eval) at the specified column. Perhaps you tried
+to run a compressed script, a binary program, or a directory as a Perl program.
+
+=item Unrecognized escape \\%c in character class passed through in regex; marked by <-- HERE in m/%s/
+
+(W regexp) You used a backslash-character combination which is not
+recognized by Perl inside character classes. The character was
+understood literally.
+The <-- HERE shows in the regular expression about where the
+escape was discovered.
+
+=item Unrecognized escape \\%c passed through
+
+(W misc) You used a backslash-character combination which is not
+recognized by Perl. The character was understood literally.
+
+=item Unrecognized escape \\%c passed through in regex; marked by <-- HERE in m/%s/
+
+(W regexp) You used a backslash-character combination which is not
+recognized by Perl. The character was understood literally.
+The <-- HERE shows in the regular expression about where the
+escape was discovered.
+
+=item Unrecognized signal name "%s"
+
+(F) You specified a signal name to the kill() function that was not
+recognized. Say C<kill -l> in your shell to see the valid signal names
+on your system.
+
+=item Unrecognized switch: -%s (-h will show valid options)
+
+(F) You specified an illegal option to Perl. Don't do that. (If you
+think you didn't do that, check the #! line to see if it's supplying the
+bad switch on your behalf.)
+
+=item Unsuccessful %s on filename containing newline
+
+(W newline) A file operation was attempted on a filename, and that
+operation failed, PROBABLY because the filename contained a newline,
+PROBABLY because you forgot to chomp() it off. See L<perlfunc/chomp>.
+
+=item Unsupported directory function "%s" called
+
+(F) Your machine doesn't support opendir() and readdir().
+
+=item Unsupported function %s
+
+(F) This machine doesn't implement the indicated function, apparently.
+At least, Configure doesn't think so.
+
+=item Unsupported function fork
+
+(F) Your version of executable does not support forking.
+
+Note that under some systems, like OS/2, there may be different flavors
+of Perl executables, some of which may support fork, some not. Try
+changing the name you call Perl by to C<perl_>, C<perl__>, and so on.
+
+=item Unsupported script encoding %s
+
+(F) Your program file begins with a Unicode Byte Order Mark (BOM) which
+declares it to be in a Unicode encoding that Perl cannot read.
+
+=item Unsupported socket function "%s" called
+
+(F) Your machine doesn't support the Berkeley socket mechanism, or at
+least that's what Configure thought.
+
+=item Unterminated attribute list
+
+(F) The lexer found something other than a simple identifier at the
+start of an attribute, and it wasn't a semicolon or the start of a
+block. Perhaps you terminated the parameter list of the previous
+attribute too soon. See L<attributes>.
+
+=item Unterminated attribute parameter in attribute list
+
+(F) The lexer saw an opening (left) parenthesis character while parsing
+an attribute list, but the matching closing (right) parenthesis
+character was not found. You may need to add (or remove) a backslash
+character to get your parentheses to balance. See L<attributes>.
+
+=item Unterminated compressed integer
+
+(F) An argument to unpack("w",...) was incompatible with the BER
+compressed integer format and could not be converted to an integer.
+See L<perlfunc/pack>.
+
+=item Unterminated verb pattern in regex; marked by <-- HERE in m/%s/
+
+(F) You used a pattern of the form C<(*VERB)> but did not terminate
+the pattern with a C<)>. Fix the pattern and retry.
+
+=item Unterminated verb pattern argument in regex; marked by <-- HERE in m/%s/
+
+(F) You used a pattern of the form C<(*VERB:ARG)> but did not terminate
+the pattern with a C<)>. Fix the pattern and retry.
+
+=item Unterminated \g{...} pattern in regex; marked by <-- HERE in m/%s/
+
+(F) You missed a close brace on a \g{..} pattern (group reference) in
+a regular expression. Fix the pattern and retry.
+
+=item Unterminated <> operator
+
+(F) The lexer saw a left angle bracket in a place where it was expecting
+a term, so it's looking for the corresponding right angle bracket, and
+not finding it. Chances are you left some needed parentheses out
+earlier in the line, and you really meant a "less than".
+
+=item untie attempted while %d inner references still exist
+
+(W untie) A copy of the object returned from C<tie> (or C<tied>) was
+still valid when C<untie> was called.
+
+=item Usage: POSIX::%s(%s)
+
+(F) You called a POSIX function with incorrect arguments.
+See L<POSIX/FUNCTIONS> for more information.
+
+=item Usage: Win32::%s(%s)
+
+(F) You called a Win32 function with incorrect arguments.
+See L<Win32> for more information.
+
+=item Useless (?-%s) - don't use /%s modifier in regex; marked by <-- HERE in m/%s/
+
+(W regexp) You have used an internal modifier such as (?-o) that has no
+meaning unless removed from the entire regexp:
+
+ if ($string =~ /(?-o)$pattern/o) { ... }
+
+must be written as
+
+ if ($string =~ /$pattern/) { ... }
+
+The <-- HERE shows in the regular expression about
+where the problem was discovered. See L<perlre>.
+
+=item Useless localization of %s
+
+(W syntax) The localization of lvalues such as C<local($x=10)> is
+legal, but in fact the local() currently has no effect. This may change at
+some point in the future, but in the meantime such code is discouraged.
+
+=item Useless (?%s) - use /%s modifier in regex; marked by <-- HERE in m/%s/
+
+(W regexp) You have used an internal modifier such as (?o) that has no
+meaning unless applied to the entire regexp:
+
+ if ($string =~ /(?o)$pattern/) { ... }
+
+must be written as
+
+ if ($string =~ /$pattern/o) { ... }
+
+The <-- HERE shows in the regular expression about
+where the problem was discovered. See L<perlre>.
+
+=item Useless use of %s in void context
+
+(W void) You did something without a side effect in a context that does
+nothing with the return value, such as a statement that doesn't return a
+value from a block, or the left side of a scalar comma operator. Very
+often this points not to stupidity on your part, but a failure of Perl
+to parse your program the way you thought it would. For example, you'd
+get this if you mixed up your C precedence with Python precedence and
+said
+
+ $one, $two = 1, 2;
+
+when you meant to say
+
+ ($one, $two) = (1, 2);
+
+Another common error is to use ordinary parentheses to construct a list
+reference when you should be using square or curly brackets, for
+example, if you say
+
+ $array = (1,2);
+
+when you should have said
+
+ $array = [1,2];
+
+The square brackets explicitly turn a list value into a scalar value,
+while parentheses do not. So when a parenthesized list is evaluated in
+a scalar context, the comma is treated like C's comma operator, which
+throws away the left argument, which is not what you want. See
+L<perlref> for more on this.
+
+This warning will not be issued for numerical constants equal to 0 or 1
+since they are often used in statements like
+
+ 1 while sub_with_side_effects();
+
+String constants that would normally evaluate to 0 or 1 are warned
+about.
+
+=item Useless use of "re" pragma
+
+(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 $x = sort @y;
+
+This is not very useful, and perl currently optimizes this away.
+
+=item Useless use of %s with no values
+
+(W syntax) You used the push() or unshift() function with no arguments
+apart from the array, like C<push(@x)> or C<unshift(@foo)>. That won't
+usually have any effect on the array, so is completely useless. It's
+possible in principle that push(@tied_array) could have some effect
+if the array is tied to a class which implements a PUSH method. If so,
+you can write it as C<push(@tied_array,())> to avoid this warning.
+
+=item "use" not allowed in expression
+
+(F) The "use" keyword is recognized and executed at compile time, and
+returns no useful value. See L<perlmod>.
+
+=item Use of bare << to mean <<"" is deprecated
+
+(D deprecated, W syntax) You are now encouraged to use the explicitly quoted
+form if you wish to use an empty line as the terminator of the here-document.
+
+=item Use of comma-less variable list is deprecated
+
+(D deprecated, W syntax) The values you give to a format should be
+separated by commas, not just aligned on a line.
+
+=item Use of chdir('') or chdir(undef) as chdir() deprecated
+
+(D deprecated) chdir() with no arguments is documented to change to
+$ENV{HOME} or $ENV{LOGDIR}. chdir(undef) and chdir('') share this
+behavior, but that has been deprecated. In future versions they
+will simply fail.
+
+Be careful to check that what you pass to chdir() is defined and not
+blank, else you might find yourself in your home directory.
+
+=item Use of /c modifier is meaningless in s///
+
+(W regexp) You used the /c modifier in a substitution. The /c
+modifier is not presently meaningful in substitutions.
+
+=item Use of /c modifier is meaningless without /g
+
+(W regexp) You used the /c modifier with a regex operand, but didn't
+use the /g modifier. Currently, /c is meaningful only when /g is
+used. (This may change in the future.)
+
+=item Use of freed value in iteration
+
+(F) Perhaps you modified the iterated array within the loop?
+This error is typically caused by code like the following:
+
+ @a = (3,4);
+ @a = () for (1,2,@a);
+
+You are not supposed to modify arrays while they are being iterated over.
+For speed and efficiency reasons, Perl internally does not do full
+reference-counting of iterated items, hence deleting such an item in the
+middle of an iteration causes Perl to see a freed value.
+
+=item Use of *glob{FILEHANDLE} is deprecated
+
+(D deprecated) You are now encouraged to use the shorter *glob{IO} form
+to access the filehandle slot within a typeglob.
+
+=item Use of /g modifier is meaningless in split
+
+(W regexp) You used the /g modifier on the pattern for a C<split>
+operator. Since C<split> always tries to match the pattern
+repeatedly, the C</g> has no effect.
+
+=item Use of implicit split to @_ is deprecated
+
+(D deprecated, W syntax) It makes a lot of work for the compiler when you
+clobber a subroutine's argument list, so it's better if you assign the results
+of a split() explicitly to an array (or list).
+
+=item Use of inherited AUTOLOAD for non-method %s() is deprecated
+
+(D deprecated) As an (ahem) accidental feature, C<AUTOLOAD> subroutines
+are looked up as methods (using the C<@ISA> hierarchy) even when the
+subroutines to be autoloaded were called as plain functions (e.g.
+C<Foo::bar()>), not as methods (e.g. C<< Foo->bar() >> or C<<
+$obj->bar() >>).
+
+This bug will be rectified in future by using method lookup only for
+methods' C<AUTOLOAD>s. However, there is a significant base of existing
+code that may be using the old behavior. So, as an interim step, Perl
+currently issues an optional warning when non-methods use inherited
+C<AUTOLOAD>s.
+
+The simple rule is: Inheritance will not work when autoloading
+non-methods. The simple fix for old code is: In any module that used
+to depend on inheriting C<AUTOLOAD> for non-methods from a base class
+named C<BaseClass>, execute C<*AUTOLOAD = \&BaseClass::AUTOLOAD> during
+startup.
+
+In code that currently says C<use AutoLoader; @ISA = qw(AutoLoader);>
+you should remove AutoLoader from @ISA and change C<use AutoLoader;> to
+C<use AutoLoader 'AUTOLOAD';>.
+
+=item Use of %s in printf format not supported
+
+(F) You attempted to use a feature of printf that is accessible from
+only C. This usually means there's a better way to do it in Perl.
+
+=item Use of %s is deprecated
+
+(D deprecated) The construct indicated is no longer recommended for use,
+generally because there's a better way to do it, and also because the
+old way has bad side effects.
+
+=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
+name. So no namespace is current at all. Using this can cause many
+otherwise reasonable constructs to fail in baffling ways. C<use strict;>
+instead.
+
+=item Use of reference "%s" as array index
+
+(W misc) You tried to use a reference as an array index; this probably
+isn't what you mean, because references in numerical context tend
+to be huge numbers, and so usually indicates programmer error.
+
+If you really do mean it, explicitly numify your reference, like so:
+C<$array[0+$ref]>. This warning is not given for overloaded objects,
+either, because you can overload the numification and stringification
+operators and then you assumably know what you are doing.
+
+=item Use of reserved word "%s" is deprecated
+
+(D deprecated) The indicated bareword is a reserved word. Future
+versions of perl may use it as a keyword, so you're better off either
+explicitly quoting the word in a manner appropriate for its context of
+use, or using a different name altogether. The warning can be
+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, deprecated) 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
+defined. It was interpreted as a "" or a 0, but maybe it was a mistake.
+To suppress this warning assign a defined value to your variables.
+
+To help you figure out what was undefined, perl will try to tell you the
+name of the variable (if any) that was undefined. In some cases it cannot
+do this, so it also tells you what operation you used the undefined value
+in. Note, however, that perl optimizes your program and the operation
+displayed in the warning may not necessarily appear literally in your
+program. For example, C<"that $foo"> is usually optimized into C<"that "
+. $foo>, and the warning will refer to the C<concatenation (.)> operator,
+even though there is no C<.> in your program.
+
+=item Using a hash as a reference is deprecated
+
+(D deprecated) You tried to use a hash as a reference, as in
+C<< %foo->{"bar"} >> or C<< %$ref->{"hello"} >>. Versions of perl <= 5.6.1
+used to allow this syntax, but shouldn't have. It is now deprecated, and will
+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
+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),
+C<each()>, or C<readdir()> as a boolean value. Each of these constructs
+can return a value of "0"; that would make the conditional expression
+false, which is probably not what you intended. When using these
+constructs in conditional expressions, test their values with the
+C<defined> operator.
+
+=item Value of CLI symbol "%s" too long
+
+(W misc) A warning peculiar to VMS. Perl tried to read the value of an
+%ENV element from a CLI symbol table, and found a resultant string
+longer than 1024 characters. The return value has been truncated to
+1024 characters.
+
+=item Variable "%s" is not available
+
+(W closure) During compilation, an inner named subroutine or eval is
+attempting to capture an outer lexical that is not currently available.
+This can happen for one of two reasons. First, the outer lexical may be
+declared in an outer anonymous subroutine that has not yet been created.
+(Remember that named subs are created at compile time, while anonymous
+subs are created at run-time.) For example,
+
+ sub { my $a; sub f { $a } }
+
+At the time that f is created, it can't capture the current value of $a,
+since the anonymous subroutine hasn't been created yet. Conversely,
+the following won't give a warning since the anonymous subroutine has by
+now been created and is live:
+
+ sub { my $a; eval 'sub f { $a }' }->();
+
+The second situation is caused by an eval accessing a variable that has
+gone out of scope, for example,
+
+ sub f {
+ my $a;
+ sub { eval '$a' }
+ }
+ f()->();
+
+Here, when the '$a' in the eval is being compiled, f() is not currently being
+executed, so its $a is not available for capture.
+
+=item Variable "%s" is not imported%s
+
+(F) While "use strict" in effect, you referred to a global variable that
+you apparently thought was imported from another module, because
+something else of the same name (usually a subroutine) is exported by
+that module. It usually means you put the wrong funny character on the
+front of your variable.
+
+=item Variable length lookbehind not implemented in m/%s/
+
+(F) Lookbehind is allowed only for subexpressions whose length is fixed and
+known at compile time. See L<perlre>.
+
+=item "%s" variable %s masks earlier declaration in same %s
+
+(W misc) A "my", "our" or "state" variable has been redeclared in the current
+scope or statement, effectively eliminating all access to the previous
+instance. This is almost always a typographical error. Note that the
+earlier variable will still exist until the end of the scope or until
+all closure referents to it are destroyed.
+
+=item Variable syntax
+
+(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 Variable "%s" will not stay shared
+
+(W closure) An inner (nested) I<named> subroutine is referencing a
+lexical variable defined in an outer named subroutine.
+
+When the inner subroutine is called, it will see the value of
+the outer subroutine's variable as it was before and during the *first*
+call to the outer subroutine; in this case, after the first call to the
+outer subroutine is complete, the inner and outer subroutines will no
+longer share a common value for the variable. In other words, the
+variable will no longer be shared.
+
+This problem can usually be solved by making the inner subroutine
+anonymous, using the C<sub {}> syntax. When inner anonymous subs that
+reference variables in outer subroutines are created, they
+are automatically rebound to the current values of such variables.
+
+=item Verb pattern '%s' has a mandatory argument in regex; marked by <-- HERE in m/%s/
+
+(F) You used a verb pattern that requires an argument. Supply an argument
+or check that you are using the right verb.
+
+=item Verb pattern '%s' may not have an argument in regex; marked by <-- HERE in m/%s/
+
+(F) You used a verb pattern that is not allowed an argument. Remove the
+argument or check that you are using the right verb.
+
+=item Version number must be a constant number
+
+(P) The attempt to translate a C<use Module n.n LIST> statement into
+its equivalent C<BEGIN> block found an internal inconsistency with
+the version number.
+
+=item Version string '%s' contains invalid data; ignoring: '%s'
+
+(W misc) The version string contains invalid characters at the end, which
+are being ignored.
+
+=item Warning: something's wrong
+
+(W) You passed warn() an empty string (the equivalent of C<warn "">) or
+you called it with no args and C<$@> was empty.
+
+=item Warning: unable to close filehandle %s properly
+
+(S) The implicit close() done by an open() got an error indication on
+the close(). This usually indicates your file system ran out of disk
+space.
+
+=item Warning: Use of "%s" without parentheses is ambiguous
+
+(S ambiguous) You wrote a unary operator followed by something that
+looks like a binary operator that could also have been interpreted as a
+term or unary operator. For instance, if you know that the rand
+function has a default argument of 1.0, and you write
+
+ rand + 5;
+
+you may THINK you wrote the same thing as
+
+ rand() + 5;
+
+but in actual fact, you got
+
+ rand(+5);
+
+So put in parentheses to say what you really mean.
+
+=item Wide character in %s
+
+(S utf8) Perl met a wide character (>255) when it wasn't expecting
+one. This warning is by default on for I/O (like print). The easiest
+way to quiet this warning is simply to add the C<:utf8> layer to the
+output, e.g. C<binmode STDOUT, ':utf8'>. Another way to turn off the
+warning is to add C<no warnings 'utf8';> but that is often closer to
+cheating. In general, you are supposed to explicitly mark the
+filehandle with an encoding, see L<open> and L<perlfunc/binmode>.
+
+=item Within []-length '%c' not allowed
+
+(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 that can be
+determined from the template alone. This is not possible if it contains an
+of the codes @, /, U, u, w or a *-length. Redesign the template.
+
+=item write() on closed filehandle %s
+
+(W closed) The filehandle you're writing to got itself closed sometime
+before now. Check your control flow.
+
+=item %s "\x%s" does not map to Unicode
+
+When reading in different encodings Perl tries to map everything
+into Unicode characters. The bytes you read in are not legal in
+this encoding, for example
+
+ utf8 "\xE4" does not map to Unicode
+
+if you try to read in the a-diaereses Latin-1 as UTF-8.
+
+=item 'X' outside of string
+
+(F) You had a (un)pack template that specified a relative position before
+the beginning of the string being (un)packed. See L<perlfunc/pack>.
+
+=item 'x' outside of string in unpack
+
+(F) You had a pack template that specified a relative position after
+the end of the string being unpacked. See L<perlfunc/pack>.
+
+=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
+your script.
+
+=item You need to quote "%s"
+
+(W syntax) You assigned a bareword as a signal handler name.
+Unfortunately, you already have a subroutine of that name declared,
+which means that Perl 5 will try to call the subroutine when the
+assignment is executed, which is probably not what you want. (If it IS
+what you want, put an & in front.)
+
+=item Your random numbers are not that random
+
+(F) When trying to initialise the random seed for hashes, Perl could
+not get any randomness out of your system. This usually indicates
+Something Very Wrong.
+
+=back
+
+=head1 SEE ALSO
+
+L<warnings>, L<perllexwarn>.
+
+=cut