- stripos: documentation ( source)
- strtolower: documentation ( source)
<?php
$ua = 'Mozilla/5.0 (Linux; U; Android 4.0.4; fr-fr; GT-S7562 Build/IMM76I) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30';
$android = stripos(strtolower($ua, 'android'));
echo $android;