在web应用开发过程中经常要判断当前客户端是不是手机浏览器访问，以便和PC环境区分。下面的函数可能会帮到你。

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;

}