- var_dump: documentation ( source)
- preg_match: documentation ( source)
- parse_url: documentation ( source)
<?php
$_url_string = 'iran.co.ir';
preg_match("/[a-z0-9\-]{1,63}\.[a-z\.]{2,6}$/", parse_url($_url_string, PHP_URL_HOST), $_domain_tld);
var_dump($_domain_tld);