This is identical to the C function, except that it can apply to a single
character or to a whole string. Consider using regular expressions and the
-C</[[:isalnum:]]/> construct instead, or possibly the C</\w/> construct.
+C</[[:alnum:]]/> construct instead, or possibly the C</\w/> construct.
=item isalpha
This is identical to the C function, except that it can apply to a single
character or to a whole string. Consider using regular expressions and the
-C</[[:isalpha:]]/> construct instead.
+C</[[:alpha:]]/> construct instead.
=item isatty
This is identical to the C function, except that it can apply to a single
character or to a whole string. Consider using regular expressions and the
-C</[[:iscntrl:]]/> construct instead.
+C</[[:cntrl:]]/> construct instead.
=item isdigit
This is identical to the C function, except that it can apply to a single
character or to a whole string. Consider using regular expressions and the
-C</[[:isdigit:]]/> construct instead, or the C</\d/> construct.
+C</[[:digit:]]/> construct instead, or the C</\d/> construct.
=item isgraph
This is identical to the C function, except that it can apply to a single
character or to a whole string. Consider using regular expressions and the
-C</[[:isgraph:]]/> construct instead.
+C</[[:graph:]]/> construct instead.
=item islower
This is identical to the C function, except that it can apply to a single
character or to a whole string. Consider using regular expressions and the
-C</[[:islower:]]/> construct instead. Do B<not> use C</a-z/>.
+C</[[:lower:]]/> construct instead. Do B<not> use C</[a-z]/>.
=item isprint
This is identical to the C function, except that it can apply to a single
character or to a whole string. Consider using regular expressions and the
-C</[[:isprint:]]/> construct instead.
+C</[[:print:]]/> construct instead.
=item ispunct
This is identical to the C function, except that it can apply to a single
character or to a whole string. Consider using regular expressions and the
-C</[[:ispunct:]]/> construct instead.
+C</[[:punct:]]/> construct instead.
=item isspace
This is identical to the C function, except that it can apply to a single
character or to a whole string. Consider using regular expressions and the
-C</[[:isspace:]]/> construct instead, or the C</\s/> construct.
+C</[[:space:]]/> construct instead, or the C</\s/> construct.
+(Note that C</\s/> and C</[[:space:]]/> are slightly different in that
+C</[[:space:]]/> can normally match a vertical tab, while C</\s/> does
+not.)
=item isupper
This is identical to the C function, except that it can apply to a single
character or to a whole string. Consider using regular expressions and the
-C</[[:isupper:]]/> construct instead. Do B<not> use C</A-Z/>.
+C</[[:upper:]]/> construct instead. Do B<not> use C</[A-Z]/>.
=item isxdigit
This is identical to the C function, except that it can apply to a single
character or to a whole string. Consider using regular expressions and the
-C</[[:isxdigit:]]/> construct instead, or simply C</[0-9a-f]/i>.
+C</[[:xdigit:]]/> construct instead, or simply C</[0-9a-f]/i>.
=item kill
$tmpfile = POSIX::tmpnam();
-See also L<File::Temp>.
+For security reasons, which are probably detailed in your system's
+documentation for the C library tmpnam() function, this interface
+should not be used; instead see L<File::Temp>.
=item tolower
Wait for a child process to change state. This is identical to Perl's
builtin C<waitpid()> function, see L<perlfunc/waitpid>.
- $pid = POSIX::waitpid( -1, &POSIX::WNOHANG );
+ $pid = POSIX::waitpid( -1, POSIX::WNOHANG );
print "status = ", ($? / 256), "\n";
=item wcstombs