PHP gets user's real IP

function getRealIpAddr()
{
    if (!emptyempty($_SERVER['HTTP_CLIENT_IP']))
    {
        $ip=$_SERVER['HTTP_CLIENT_IP'];
    }
    elseif (!emptyempty($_SERVER['HTTP_X_FORWARDED_FOR']))
    //to check ip is pass from proxy
    {
        $ip=$_SERVER['HTTP_X_FORWARDED_FOR'];
    }
    else
    {
        $ip=$_SERVER['REMOTE_ADDR'];
    }
    return $ip;
}

用法：

$ip = getRealIpAddr();
echo $ip;
?>

PHP