php判断用户是否使用手机设备

<?php
 function is_mobile() {
  $user_agent = $_SERVER[‘HTTP_USER_AGENT‘];
  $mobile_agents = Array("240x320","acer","acoon","acs-","abacho","ahong","airness","alcatel","amoi","android","anywhereyougo.com","applewebkit/525","applewebkit/532","asus","audio","au-mic","avantogo","becker","benq","bilbo","bird","blackberry","blazer","bleu","cdm-","compal","coolpad","danger","dbtel","dopod",
"elaine","eric","etouch","fly ","fly_","fly-","go.web","goodaccess","gradiente","grundig","haier","hedy","hitachi","htc","huawei","hutchison","inno","ipad","ipaq","ipod","jbrowser","kddi","kgt","kwc","lenovo","lg ","lg2","lg3","lg4","lg5","lg7","lg8","lg9","lg-","lge-","lge9","longcos","maemo","mercator","meridian",
"micromax","midp","mini","mitsu","mmm","mmp","mobi","mot-","moto","nec-","netfront","newgen","nexian","nf-browser",
"nintendo","nitro","nokia","nook",
"novarra","obigo","palm","panasonic",
"pantech","philips","phone","pg-","playstation","pocket","pt-","qc-","qtek","rover","sagem","sama","samu","sanyo","samsung","sch-","scooter","sec-","sendo","sgh-","sharp","siemens","sie-","softbank","sony","spice",
"sprint","spv","symbian","tablet","talkabout","tcl-","teleca","telit",
"tianyu","tim-","toshiba","tsm","up.browser","utec","utstar","verykool","virgin","vk-","voda","voxtel","vx","wap","wellco","wig browser","wii","windows ce","wireless","xda","xde","zte");
  $is_mobile = false;
  foreach ($mobile_agents as $device) {
   if (stristr($user_agent, $device)) {
    $is_mobile = true;
    break;
   }
  }
  return $is_mobile;
 }
 
 if( is_mobile() ){
  echo ‘mobile‘; 
 }else{
  echo ‘wangye‘;  
 }
 
 
 $agent = $_SERVER[‘HTTP_USER_AGENT‘];
 if(strpos($agent,"NetFront") || strpos($agent,"iPhone") || strpos($agent,"MIDP-2.0") || strpos($agent,"Opera Mini") || strpos($agent,"UCWEB") || strpos($agent,"Android") || strpos($agent,"Windows CE") || strpos($agent,"SymbianOS")){
  echo ‘mobile‘;
  //header("Location:xxxxxxxx");
 }else{
  echo ‘wangye‘; 
 }
 
 
 
 
?>