PHP ตรวจสอบ OS ว่าเครื่องนั้นใช้อะไร

<?php
$iphone = strpos($_SERVER['HTTP_USER_AGENT'],"iPhone");
$android = strpos($_SERVER['HTTP_USER_AGENT'],"Android");
$palmpre = strpos($_SERVER['HTTP_USER_AGENT'],"webOS");
$berry = strpos($_SERVER['HTTP_USER_AGENT'],"BlackBerry");
$ipod = strpos($_SERVER['HTTP_USER_AGENT'],"iPod");

if ($iphone || $android || $palmpre || $ipod || $berry == true)
{
    echo "<script>window.location='http://www.phpmind.com'</script>";
 }
?>

 เครดิต http://www.phpmind.com/blog/