获取客户端真实ip

// 获取客户端真实ip()
    protected function getIP()
    {
    global $ip;
    if (getenv("HTTP_CLIENT_IP"))
    $ip = getenv("HTTP_CLIENT_IP");
    else if(getenv("HTTP_X_FORWARDED_FOR"))
    $ip = getenv("HTTP_X_FORWARDED_FOR");
    else if(getenv("REMOTE_ADDR"))
    $ip = getenv("REMOTE_ADDR");
    else $ip = "Unknow";
    return $ip;
    }