name, and not a subroutine call. C<exists &sub()> will generate this
error.
+=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 Argument "%s" isn't numeric%s
(W numeric) The indicated string was fed as an argument to an operator
function correctly, you may put an ampersand before the name to avoid
the warning. See L<perlsub>.
+=item Can only compress unsigned integers
+
+(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 Cannot compress integer
+
+(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
+
+(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 take a count
(F) You had an unpack template indicating a counted-length string, but
=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>.
+(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
+(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 syntax) An illegal character was found in a prototype declaration. Legal
characters in prototypes are $, @, %, *, ;, [, ], &, and \.
+=item Illegal declaration of anonymous subroutine
+
+(F) When using the C<sub> keyword to construct an anonymous subroutine,
+you must always specify a block of code. See L<perlsub>.
+
=item Illegal division by zero
(F) You tried to divide a number by 0. Either something was wrong in
(F) You can't use system(), exec(), or a piped open in a setuid or
setgid script if any of C<$ENV{PATH}>, C<$ENV{IFS}>, C<$ENV{CDPATH}>,
-C<$ENV{ENV}> or C<$ENV{BASH_ENV}> 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>.
+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
internally--subject to loss of precision errors in subsequent
operations.
+=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.
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
+=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>.
(W unpack) The given character is not a valid 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
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
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 & ($y == 0)>, due to the
+higher precedence of C<==>. This is probably not what you want. (If you
+really meant to write this, disable the warning, or, better, write
+C<$x & ($y == 0 ? 1 : 0)>).
+
=item Possible unintended interpolation of %s in string
(W ambiguous) You said something like `@foo' in a double-quoted string
One possible workaround is to force Perl to use magical string increment
by prepending "0" to your numbers.
+=item read() on closed filehandle %s
+
+(W closed) You tried to read from a closed filehandle.
+
+=item read() on unopened filehandle %s
+
+(W unopened) You tried to read from a filehandle that was never opened.
+
=item readline() on closed filehandle %s
(W closed) The filehandle you're reading from got itself closed sometime
construct. Remember that bracketing delimiters count nesting level.
Missing the leading C<$> 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 %sseek() on unopened filehandle
(W unopened) You tried to use the seek() or sysseek() function on a
(F) The final summary message when a C<perl -c> succeeds.
+=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",
(F) Your version of the C library apparently doesn't do times(). I
suspect you're not running on Unix.
+=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 few args to syscall
(F) There has to be at least one argument to syscall() to specify the