PHP 实现判断用户是否手机访问

$agent = check_wap();
if( $agent )
{
  header(Location: http://www.nowamagic.net);
  exit;
}
// check if wap
function check_wap(){
  // 先检查是否为wap代理，准确度高
  if(stristr($_SERVER[HTTP_VIA],"wap")){
      return true;
  }
  // 检查浏览器是否接受 WML.
  elseif(strpos(strtoupper($_SERVER[HTTP_ACCEPT]),"VND.WAP.WML") > 0){
      return true;
 }
 //检查USER_AGENT
 elseif(preg_match(/(blackberry|configuration\/cldc|hp |hp-|htc |htc_|htc-|iemobile|kindle|midp|mmp|motorola|mobile|nokia|opera mini|opera |Googlebot-Mobile|YahooSeeker\/M1A1-R2D2|android|iphone|ipod|mobi|palm|palmos|pocket|portalmmm|ppc;|smartphone|sonyericsson|sqh|spv|symbian|treo|up.browser|up.link|vodafone|windows ce|xda |xda_)/i, $_SERVER[HTTP_USER_AGENT])){
      return true;          
  }
  else{
      return false; 
 }
}

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; 
}