How to Detect Visitor Country and City in PHP Using geoplugin.net

This simple function uses the free geoplugin.net service to detect a website visitor's country code and city.

You can use this data to pre‑fill hidden form fields, or for other valuable purposes such as blocking access from specific regions.

function getLocationInfoByIp(){
    $client  = @$_SERVER['HTTP_CLIENT_IP'];
    $forward = @$_SERVER['HTTP_X_FORWARDED_FOR'];
    $remote  = @$_SERVER['REMOTE_ADDR'];
    $result  = array('country'=>'', 'city'=>'');
    if(filter_var($client, FILTER_VALIDATE_IP)){
        $ip = $client;
    }elseif(filter_var($forward, FILTER_VALIDATE_IP)){
        $ip = $forward;
    }else{
        $ip = $remote;
    }
    $ip_data = @json_decode(file_get_contents("http://www.geoplugin.net/json.gp?ip=".$ip));
    if($ip_data && $ip_data->geoplugin_countryName != null){
        $result['country'] = $ip_data->geoplugin_countryCode;
        $result['city'] = $ip_data->geoplugin_city;
    }
    return $result;
}

Source: 21CTO Community