PHP识别电脑还是手机访问网站

最近，客户要求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。

<?php
function isMobile(){ 
    $useragent=isset($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : ''; 
    $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; 
    } 
}
if (isMobile())
    echo '手机登录m.php100.com';
else
    echo '电脑登录www.php100.com';
?>