PHP 判断用户的设备是否是移动设备

<?php function isMobile() {     // 如果有HTTP_X_WAP_PROFILE则一定是移动设备     if (isset ($_SERVER["HTTP_X_WAP_PROFILE"]))     {         return true;     }     // 如果via信息含有wap则一定是移动设备,部分服务商会屏蔽该信息     if (isset ($_SERVER["HTTP_VIA"]))     {         // 找不到为flase,否则为true         return stristr($_SERVER["HTTP_VIA"], "wap") ? true : false;     }     // 脑残法，判断手机发送的客户端标志,兼容性有待提高     if (isset ($_SERVER["HTTP_USER_AGENT"]))     {         $clientkeywords = array ("nokia",             "sony",             "ericsson",             "mot",             "samsung",             "htc",             "sgh",             "lg",             "sharp",             "sie-",             "philips",             "panasonic",             "alcatel",             "lenovo",             "iphone",             "ipod",             "blackberry",             "meizu",             "android",             "netfront",             "symbian",             "ucweb",             "windowsce",             "palm",             "operamini",             "operamobi",             "openwave",             "nexusone",             "cldc",             "midp",             "wap",             "mobile"             );         // 从HTTP_USER_AGENT中查找手机浏览器的关键字         if (preg_match("/(" . implode("|", $clientkeywords) . ")/i", strtolower($_SERVER["HTTP_USER_AGENT"])))         {             return true;         }     }     //