public static function getUserPlatform()
    {
        $user_agent = $_SERVER['HTTP_USER_AGENT'];
        $user_platform = 'unknown';

        if (false !== stripos($user_agent, 'linux')) {
            $user_platform = 'Linux';
        } elseif (preg_match('/macintosh|mac os x/i', $user_agent)) {
            $user_platform = 'Mac';
        } elseif (preg_match('/windows|win32/i', $user_agent)) {
            $user_platform = 'Windows';
        }

        return $user_platform;
    }