php 判断扫码的客户端是支付宝还是微信

<?php 
if (strstr($_SERVER['HTTP_USER_AGENT'], 'AlipayClient')) { 
   echo '扫码的设备为支付宝app'; 
} else if(strstr($_SERVER['HTTP_USER_AGENT'], 'MicroMessenger')){
   echo '扫码的设备为微信app'; 
}else {
   echo '非微信或支付宝APP'; 
}