$proxy =~
m/(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?).(25[0-5]|2[0-4]
[0-9]|[01]?[0-9][0-9]?).(25[0-5]|2[0-4][0-9]|[01]?[0-9]
[0-9]?).(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?):([0-9][0-9]
[0-9][0-9])/ && print $con ‘privmsg $xnick :$1.$2.$3.$4:$5n’;

# Well well. Isn’t that a, uh, “interesting” regex

Source: Direct link to the source code
Software: Perl Underground
Programming language: Perl