PHP获取真实的客户IP的方法

if ($_SERVER["HTTP_X_FORWARDED_FOR"]) {
      if ($_SERVER["HTTP_CLIENT_IP"]) {
            $proxy = $_SERVER["HTTP_CLIENT_IP"];
      } else {
           $proxy = $_SERVER["REMOTE_ADDR"];
      }
     $ip = $_SERVER["HTTP_X_FORWARDED_FOR"];
} else {
     if ($_SERVER["HTTP_CLIENT_IP"]) {
            $ip = $_SERVER["HTTP_CLIENT_IP"];
      } else {
           $ip = $_SERVER["REMOTE_ADDR"];
      }
}
echo "Your IP $ip";
if (isset($proxy)) {
echo "Your proxy IP is $proxy";
}