Thoughts on best way to test subdomain

dev_test.php

<?php
//faster using strpos
$staging_subdomains = array(
    's1',
    's2',
    's3',
    's4',
    's5',
    'mac',
    'local',
    'mac-upgrade',
);
foreach($staging_subdomains as $needle){
    if(strpos($_SERVER['HTTP_HOST'], $needle) !== false){
        Mage::setIsDeveloperMode(true);
        ini_set('display_errors', 1);
        break;
    }
}