有时候很实用在一些场合，留住备用吧

复制代码 代码如下:
function is_mobile_request()  
    {  
      $_SERVER['ALL_HTTP'] = isset($_SERVER['ALL_HTTP']) ? $_SERVER['ALL_HTTP'] : '';  
      $mobile_browser = '0';  
      if(preg_match('/(up.browser|up.link|mmp|symbian|smartphone|midp|wap|phone|iphone|ipad|ipod|android|xoom)/i', strtolower($_SERVER['HTTP_USER_AGENT'])))  
        $mobile_browser++;  
      if((isset($_SERVER['HTTP_ACCEPT'])) and (strpos(strtolower($_SERVER['HTTP_ACCEPT']),'application/vnd.wap.xhtml+xml') !== false))  
        $mobile_browser++;  
      if(isset($_SERVER['HTTP_X_WAP_PROFILE']))  
        $mobile_browser++;  
      if(isset($_SERVER['HTTP_PROFILE']))  
        $mobile_browser++;  
      $mobile_ua = strtolower(substr($_SERVER['HTTP_USER_AGENT'],0,4));  
      $mobile_agents = array(  
            'w3c ','acs-','alav','alca','amoi','audi','avan','benq','bird','blac',  
            'blaz','brew','cell','cldc','cmd-','dang','doco','eric','hipt','inno',  
            'ipaq','java','jigs','kddi','keji','leno','lg-c','lg-d','lg-g','lge-',  
            'maui','maxo','midp','mits','mmef','mobi','mot-','moto','mwbp','nec-',  
            'newt','noki','oper','palm','pana','pant','phil','play','port','prox',  
            'qwap','sage','sams','sany','sch-','sec-','send','seri','sgh-','shar',  
            'sie-','siem','smal','smar','sony','sph-','symb','t-mo','teli','tim-',  
            'tosh','tsm-','upg1','upsi','vk-v','voda','wap-','wapa','wapi','wapp',  
            'wapr','webc','winw','winw','xda','xda-'  
            );  
      if(in_array($mobile_ua, $mobile_agents))  
        $mobile_browser++;  
      if(strpos(strtolower($_SERVER['ALL_HTTP']), 'operamini') !== false)  
        $mobile_browser++;  
      // Pre-final check to reset everything if the user is on Windows  
      if(strpos(strtolower($_SERVER['HTTP_USER_AGENT']), 'windows') !== false)  
        $mobile_browser=0;  
      // But WP7 is also Windows, with a slightly different characteristic  
      if(strpos(strtolower($_SERVER['HTTP_USER_AGENT']), 'windows phone') !== false)  
        $mobile_browser++;  
      if($mobile_browser>0)  
        return true;  
      else 
        return false;  
    }

文章来源：http://yi1.com.cn/posts/781

php 根据HTTP_USER_AGENT 判断用户浏览器类型
复制代码 代码如下:
function browsers(){
   global $HTTP_USER_AGENT ;
   if (isset($HTTP_USER_AGENT)){
    $sAgent = $HTTP_USER_AGENT;
   }else{
    $sAgent = $_SERVER['HTTP_USER_AGENT'];
   }
   if (strpos($sAgent,'MSIE') !== false && strpos($sAgent,'mac') === false && strpos($sAgent,'Opera') === false){
    $iVersion = (float)substr($sAgent,strpos($sAgent,'MSIE') + 5,3);
    return ($iVersion >= 5.5) ;
   }else if (strpos($sAgent,'Gecko/') !== false){
    $iVersion = (int)substr($sAgent,strpos($sAgent,'Gecko/') + 6,8);
    return ($iVersion >= 20030210) ;
   }else{
    return false;
   }
  }