Quote: Go ahead... make my day.
-- Dirty Harry
(Courtesy of fortune cookies)

Welcome to the Cool Spot of the Sun

PHP, the most informative source on it is on the PHP.Net Site.
Regex under PHP Common functions in Regular expressions for PHP are in PCRE or Perl Compatible RegEx. [Note: For a tutorial on Regular Expression see here]

preg_match ->match once

preg_match_all ->match globally

preg_replace ->replace

This is an online demo of the PHP based PCRE library powers.HERE

Rest of tutorial Under Construction