cURL, get link behind redirect tutorial

function get_link2($link1) {
$ch = curl_init($link1);

curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_NOBODY, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

$response = curl_exec($ch);
curl_close($ch);

$header = "Location: ";
$pos = strpos($response, $header);
$pos += strlen($header);
$link2 = substr($response, $pos, strpos($response, "\r\n", $pos)-$pos);
return $link2; }