Print out a city with the users IP adress

Question

For a little project of mine i want to print the city (the name) on the screen with the ip of the user, i already have something to get his/her IP but i dont how to get the city where he/she is from....

the code i use right now to get the ip+:

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();

echo $user_ip; // Output IP address [Ex: 177.87.193.134]

credits: How to get a user's IP address in PHP?

does anyone have an idea how i should get it to work? You dont have to write something for me, but a hint or a link to a othore tread would really help! Tips are always welcome!