php查看真实ip

if (isset($_SERVER["HTTP_X_FORWARDED_FOR"])&&$_SERVER["HTTP_X_FORWARDED_FOR"]) 
{
    if ($_SERVER["HTTP_CLIENT_IP"]) 
    {
           $proxy = $_SERVER["HTTP_CLIENT_IP"];
      }
    else
    {
        $proxy = $_SERVER["REMOTE_ADDR"];
      }
      $ip = $_SERVER["HTTP_X_FORWARDED_FOR"];
} 
else 
{
    if (isset($_SERVER["HTTP_CLIENT_IP"])&&$_SERVER["HTTP_CLIENT_IP"]) 
    {
           $ip = $_SERVER["HTTP_CLIENT_IP"];
      } 
    else 
    {
           $ip = $_SERVER["REMOTE_ADDR"];
    }
}
if (isset($proxy)) 
    $ip = $proxy;