怎样用php识别是电脑还是手机访问网站

网站要判断是手机访问还是电脑访问，然后显示不同的信息，所以就在网上找了这个，不是原创，重在分享。

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; 
} 
}
if (isMobile())
echo '手机登录m.php100.com';
else
echo '电脑登录www.php100.com';
?>