php判断是手机访问还是电脑访问

<?php

function isMobile(){    

   $useragent=isset($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : '';    

   $useragent_commentsblock=preg_match('|.∗?.∗?|',$useragent,$matches)>0?$matches[0]:'';      

   function CheckSubstrs($substrs,$text){    

       foreach($substrs as $substr)    

           if(false!==strpos($text,$substr)){    

               return true;    

           }    

           return false;    

   }  

   $mobile_os_list=array('Google Wireless Transcoder','Windows CE','WindowsCE','Symbian','Android','armv6l','armv5','Mobile','CentOS','mowser','AvantGo','Opera Mobi','J2ME/MIDP','Smartphone','Go.Web','Palm','iPAQ');  

   $mobile_token_list=array('Profile/MIDP','Configuration/CLDC-','160×160','176×220','240×240','240×320','320×240','UP.Browser','UP.Link','SymbianOS','PalmOS','PocketPC','SonyEricsson','Nokia','BlackBerry','Vodafone','BenQ','Novarra-Vision','Iris','NetFront','HTC_','Xda_','SAMSUNG-SGH','Wapaka','DoCoMo','iPhone','iPod');    

   $found_mobile=CheckSubstrs($mobile_os_list,$useragent_commentsblock) ||    

             CheckSubstrs($mobile_token_list,$useragent);    

   if ($found_mobile){    

       return true;    

   }else{    

       return false;    

   }    

}  

//执行函数

if (isMobile()){

   echo 'shouji';    

}  else {

   echo 'diannao';      

}