- var_dump: documentation ( source)
- preg_match: documentation ( source)
<?php
preg_match('#^/vendorLookup/search/(?P<mac>(?:[[:xdigit:]]{2}([-:]))(?:[[:xdigit:]]{2}\2){4}[[:xdigit:]]{2})$#s', '/vendorLookup/search/aa:aa:aa:aa:aa:aa', $match);
var_dump($match);