http://www.perlmonks.org?node_id=23394

#!/usr/local/bin/perl -w # Turn on warn so that errors won't trouble ya. use strict if ( ! $AQuickHack ); # Keeps your program both safe and on track $program =~ s/local/my/ if ( $version >= "Perl 5" ) && print "Now you're not a Perl quack!";