context.set_main_group(my_option_group);
    try
    {
        context.parse(argc, argv);
    }
    catch (Glib::OptionError& e)
    {
        cerr << "Error " << e.code() << ": " << e.what() << endl;
    }

    if (argc <= 2)
    {
        cerr << "Missing filename" << endl;
    }