#include <gio/gio.h>

static gchar *opt_name         = NULL;

static gboolean opt_system_bus = FALSE;

static gboolean opt_auto_start = FALSE;

static GOptionEntry opt_entries[] =

{

  { "name", 'n', 0, G_OPTION_ARG_STRING, &opt_name, "Name to watch", NULL },

  { "system-bus", 's', 0, G_OPTION_ARG_NONE, &opt_system_bus, "Use the system-bus instead of the session-bus", NULL },

  { "auto-start", 'a', 0, G_OPTION_ARG_NONE, &opt_auto_start, "Instruct the bus to launch an owner for the name", NULL},

  { NULL}

};

static void

on_name_appeared (GDBusConnection *connection,

                  const gchar     *name,

                  const gchar     *name_owner,

                  gpointer         user_data)

{

  g_print ("Name %s on %s is owned by %s\n",

           name,

           opt_system_bus ? "the system bus" : "the session bus",

           name_owner);

}

static void

on_name_vanished (GDBusConnection *connection,

                  const gchar     *name,

                  gpointer         user_data)

{

  g_print ("Name %s does not exist on %s\n",

           name,

           opt_system_bus ? "the system bus" : "the session bus");

}

int

main (int argc, char *argv[])

{

  guint watcher_id;

  GMainLoop *loop;

  GOptionContext *opt_context;

  GError *error;

  GBusNameWatcherFlags flags;

  error = NULL;

  opt_context = g_option_context_new ("g_bus_watch_name() example");

  g_option_context_set_summary (opt_context,

                                "Example: to watch the power manager on the session bus, use:\n"

                                "\n"

                                "  ./example-watch-name -n org.gnome.PowerManager");

  g_option_context_add_main_entries (opt_context, opt_entries, NULL);

  if (!g_option_context_parse (opt_context, &argc, &argv, &error))

    {

      g_printerr ("Error parsing options: %s", error->message);

      goto out;

    }

  if (opt_name == NULL)

    {

      g_printerr ("Incorrect usage, try --help.\n");

      goto out;

    }

  flags = G_BUS_NAME_WATCHER_FLAGS_NONE;

  if (opt_auto_start)

    flags |= G_BUS_NAME_WATCHER_FLAGS_AUTO_START;

  watcher_id = g_bus_watch_name (opt_system_bus ? G_BUS_TYPE_SYSTEM : G_BUS_TYPE_SESSION,

                                 opt_name,

                                 flags,

                                 on_name_appeared,

                                 on_name_vanished,

                                 NULL,

                                 NULL);

  loop = g_main_loop_new (NULL, FALSE);

  g_main_loop_run (loop);

  g_bus_unwatch_name (watcher_id);

 out:

  g_option_context_free (opt_context);

  g_free (opt_name);

  return 0;

}