PHP_PHPチュートリアルのHTTP_USER_AGENTで携帯電話端末かどうかを判定する関数コード

function is_mobile_request()
{
$_SERVER['ALL_HTTP'] = isset($_SERVER['ALL_HTTP']) ? $_SERVER['ALL_HTTP'] : '';  
$mobile_browser = '0';  
if(preg_match('/(up.browser|up.link|mmp|symbian|smartphone|midp|wap|phone|iphone|ipad|ipod|android|xoom)/i', strto lower($_SERVER['HTTP_USER_AGENT' ])))
$mobile_browser++;  
if((isset($_SERVER['HTTP_ACCEPT'])) and (strpos(strto lower($_SERVER['HTTP_ACCEPT']),'application/vnd.wap.xhtml+xml') !== false))
$モバイルブラウザ++;  
if(isset($_SERVER['HTTP_X_WAP_PROFILE']))
$mobile_browser++;  
if(isset($_SERVER['HTTP_PROFILE']))
$mobile_browser++;  
$mobile_ua = strto lower(substr($_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))
$mobile_browser++;  
if(strpos(strto lower($_SERVER['ALL_HTTP']), 'operamini') !== false)
$mobile_browser++;  
// ユーザーが Windows を使用している場合にすべてをリセットするための最終前チェック
if(strpos(strto lower($_SERVER['HTTP_USER_AGENT']), 'windows') !== false)
$mobile_browser=0;  
// しかし、WP7 も Windows であり、少し異なる特徴があります
if(strpos(strto lower($_SERVER['HTTP_USER_AGENT']), 'windows Phone') !== false)
$mobile_browser++;  
if($mobile_browser>0)
trueを返します。  
else
false を返します。  
}

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;
}
}