function getIP() {
   
    if (isset($_SERVER["HTTP_CDN_SRC_IP"])) {
        $realip = $_SERVER["HTTP_CDN_SRC_IP"];
    } else if (isset($_SERVER['HTTP_X_FORWARDED_FOR']) && preg_match('/^([0-9]{1,3}\.){3}[0-9]{1,3}$/',$_SERVER['HTTP_X_FORWARDED_FOR'])) {
        $realip = $_SERVER['HTTP_X_FORWARDED_FOR'];
    } elseif (isset($_SERVER['HTTP_CLIENT_IP'])) {
        $realip = $_SERVER['HTTP_CLIENT_IP'];
    } else {
        $realip = $_SERVER['REMOTE_ADDR'];
    }

    //如果是代理服务器，有可能返回两个IP,这是取第一个即可
    if (stristr($realip, ','))
        $realip = strstr($realip, ',', true);
    return (str_replace('#', '', $realip));
}