am I in...?

desktop.vala

using GLib;

private bool in_desktop (string desktop) {
        var env = GLib.Environment.get_variable("XDG_CURRENT_DESKTOP");

        if (env == null)
                return false;

        var desktop_parts = env.split(":");

        return desktop in desktop_parts;
}

public int main (string[] args) {
        print("Am I in GNOME? " + (in_desktop("GNOME") ? "yes" : "no") + "\n");
        return 0;
}