<?PHP

function getUserIP()
{
    $client  = @$_SERVER['HTTP_CLIENT_IP'];
    $forward = @$_SERVER['HTTP_X_FORWARDED_FOR'];
    $remote  = $_SERVER['REMOTE_ADDR'];

    if(filter_var($client, FILTER_VALIDATE_IP))
    {
        $ip = $client;
    }
    elseif(filter_var($forward, FILTER_VALIDATE_IP))
    {
        $ip = $forward;
    }
    else
    {
        $ip = $remote;
    }

    return $ip;
}


$user_ip = getUserIP();
$write = $user_ip."<br>";


$fp = fopen('ips.html', 'a+');
fwrite($fp, $write);
fclose($fp);

// the content of 'data.txt' is now 123 and not 23!


?>