php curl 302跳转的最终结果

function getCurl(){
   $res = null;
        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_REFERER, $url);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
        curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.119 Safari/537.36');
        $data = curl_exec($ch);
        $redirect_url = curl_getinfo($ch, CURLINFO_EFFECTIVE_URL);

        if ($redirect_url == $url) {
            $res = $data;
        } else {
            $res = self::get($redirect_url);
        }
        curl_close($ch);
        return $res;
}