gistfile1.php

<?php
	$str = '[0710:020602938:7041]';

	switch(1) {
		case preg_match('/^(\[)[A-Z0-9]{4}:(' . rand(10000,29999) . '|' . rand(50000,99999) . '):[A-z]{3}(\])(.*)+/', $str):
			/* ... */
			break;
		case preg_match('/^(\[)[A-Z0-9]{4}:[0-9]{9}:[0-9]{4}(\])+/', $str):
			/* ... */
			break;
		default:
			/* ... */
			break;
	}