PHP如何通过URL访问，获得新的URL 两种方法

1.1

$url = 'http://passport.drcloud.cn/api/logon.asp?id=1&ru=http://203.158.158.122/store/thirdLogin.php&tw=1800&sm=0&lc=2052';
$newurl = getMapUrl($url);
echo $newurl;
 
function getMapUrl($url){
    $result = get_headers($url, true);
    return isset($result['Location'])? $result['Location'] : '';
}

1.2

$url = 'http://passport.drcloud.cn/api/logon.asp?id=1&ru=http://203.158.158.122/store/thirdLogin.php&tw=1800&sm=0&lc=2052';
$newurl = getMapUrl($url);
echo $newurl;

function getMapUrl($url){
    file_get_contents($url);
    $result = $http_response_header;
    if($result){
        foreach($result as $val){
            if(substr($val,0,10)=='Location: '){
                return str_replace('Location: ','', $val);
            }
        }
    }
    return '';
}

2

$url = 'http://passport.drcloud.cn/api/logon.asp?id=1&ru=http://203.158.158.122/store/thirdLogin.php&tw=1800&sm=0&lc=2052';
$newurl = getHeadersNew($url);
var_dump($newurl);
function getHeadersNew($url){ 
    $ch= curl_init(); 
    curl_setopt($ch, CURLOPT_URL, $url); 
    curl_setopt($ch, CURLOPT_NOBODY, 1); 
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); 
    curl_setopt($ch, CURLOPT_HEADER, 1); 
    $f=curl_exec($ch); 
    curl_close($ch); 
    $h=explode("
",$f); 
    $r=array(); 
    foreach( $h as $t){ 
      $rr=explode(":",$t,2); 
      if(count($rr)==2 ){ $r[$rr[0]]=trim($rr[1]);} 
    } 
    return $r; 
}