http://www.perlmonks.org?node_id=615758


in reply to Validating IP Address

This is a variation of one from the Book "Mastering Regular Expressions" by Jeffrey Friedl, which I highly recommend.
unless ( $ip =~ m/^(?:[1]?\d\d?|2[0-4]\d|25[0-5])\. (?:[1]?\d\d?|2[0-4]\d|25[0-5])\. (?:[1]?\d\d?|2[0-4]\d|25[0-5])\. (?:[1]?\d\d?|2[0-4]\d|25[0-5])$ /x ) { # do something }
Best Regards,
Wonko