{{getip}}

/action/getip.php

<?php
    // determine IP
    $tpl->ip = $ip = $this->get_user_ip();
    
    // resolve IP and determine host
    $tpl->host = gethostbyaddr($ip);

/action/template/getip.tpl

[ === main === ]
 
[ ' ip ' ]<br>
[ ' host ' ]<br>