/**
 * 判断当前访问的用户是 PC端 还是 手机端 返回true 为手机端 false 为PC 端
 * @return boolean
 */
function isMobile(){ 
  $useragent=isset($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : ''; 
  //echo $useragent;die;
  $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; 
  } 
}