line after the program name but before any filename arguments (or before
a B<-->). Any switch found there is removed from @ARGV and sets the
corresponding variable in the Perl program. The following program
-prints "true" if and only if the program is invoked with a B<-xyz> switch.
+prints "1" if the program is invoked with a B<-xyz> switch, and "abc"
+if it is invoked with B<-xyz=abc>.
#!/usr/bin/perl -s
- if ($xyz) { print "true\n" }
+ if ($xyz) { print "$xyz\n" }
=item B<-S>
C<__WARN__> hooks, as described in L<perlvar> and L<perlfunc/warn>.
See also L<perldiag> and L<perltrap>. A new, fine-grained warning
facility is also available if you want to manipulate entire classes
-of warnings; see L<warnings> (or better yet, its source code) about
-that.
+of warnings; see L<warnings> or L<perllexwarn>.
=item B<-W>
-Enables all warnings regardless of
+Enables all warnings regardless of C<no warnings> or C<$^W>.
See L<perllexwarn>.
=item B<-X>
-Disables all warnings regardless of
+Disables all warnings regardless of C<use warnings> or C<$^W>.
See L<perllexwarn>.
=item B<-x> I<directory>