1  #include <gio/gio.h>
       2  
       3  static gchar *opt_name         = NULL;
       4  static gboolean opt_system_bus = FALSE;
       5  static gboolean opt_auto_start = FALSE;
       6  
       7  static GOptionEntry opt_entries[] =
       8  {
       9    { "name", 'n', 0, G_OPTION_ARG_STRING, &opt_name, "Name to watch", NULL },
      10    { "system-bus", 's', 0, G_OPTION_ARG_NONE, &opt_system_bus, "Use the system-bus instead of the session-bus", NULL },
      11    { "auto-start", 'a', 0, G_OPTION_ARG_NONE, &opt_auto_start, "Instruct the bus to launch an owner for the name", NULL},
      12    G_OPTION_ENTRY_NULL
      13  };
      14  
      15  static void
      16  on_name_appeared (GDBusConnection *connection,
      17                    const gchar     *name,
      18                    const gchar     *name_owner,
      19                    gpointer         user_data)
      20  {
      21    g_print ("Name %s on %s is owned by %s\n",
      22             name,
      23             opt_system_bus ? "the system bus" : "the session bus",
      24             name_owner);
      25  }
      26  
      27  static void
      28  on_name_vanished (GDBusConnection *connection,
      29                    const gchar     *name,
      30                    gpointer         user_data)
      31  {
      32    g_print ("Name %s does not exist on %s\n",
      33             name,
      34             opt_system_bus ? "the system bus" : "the session bus");
      35  }
      36  
      37  int
      38  main (int argc, char *argv[])
      39  {
      40    guint watcher_id;
      41    GMainLoop *loop;
      42    GOptionContext *opt_context;
      43    GError *error;
      44    GBusNameWatcherFlags flags;
      45  
      46    error = NULL;
      47    opt_context = g_option_context_new ("g_bus_watch_name() example");
      48    g_option_context_set_summary (opt_context,
      49                                  "Example: to watch the power manager on the session bus, use:\n"
      50                                  "\n"
      51                                  "  ./example-watch-name -n org.gnome.PowerManager");
      52    g_option_context_add_main_entries (opt_context, opt_entries, NULL);
      53    if (!g_option_context_parse (opt_context, &argc, &argv, &error))
      54      {
      55        g_printerr ("Error parsing options: %s", error->message);
      56        goto out;
      57      }
      58    if (opt_name == NULL)
      59      {
      60        g_printerr ("Incorrect usage, try --help.\n");
      61        goto out;
      62      }
      63  
      64    flags = G_BUS_NAME_WATCHER_FLAGS_NONE;
      65    if (opt_auto_start)
      66      flags |= G_BUS_NAME_WATCHER_FLAGS_AUTO_START;
      67  
      68    watcher_id = g_bus_watch_name (opt_system_bus ? G_BUS_TYPE_SYSTEM : G_BUS_TYPE_SESSION,
      69                                   opt_name,
      70                                   flags,
      71                                   on_name_appeared,
      72                                   on_name_vanished,
      73                                   NULL,
      74                                   NULL);
      75  
      76    loop = g_main_loop_new (NULL, FALSE);
      77    g_main_loop_run (loop);
      78  
      79    g_bus_unwatch_name (watcher_id);
      80  
      81   out:
      82    g_option_context_free (opt_context);
      83    g_free (opt_name);
      84  
      85    return 0;
      86  }