Detect idleness, and log-out of Gnome.

/* xidle.c
 * Grab XScreenSaver Extension Idle information
 * Idea ripped from GAIM
 * by Spirilis
 * + output modifications by f0rked
 * 2005-04-26
 *
 * I ripped over the original rip. A quick dirty hack
 * + logout after 30 mins.
 * by Ritesh Khadgaray <khadgaray@gmail.com>
 * Fri Jul 14 22:38:55 2006
 *
 * Distributed under the terms of the GNU General Public License version 2:
 * (original GAIM copyright notice follows)
 * Gaim is the legal property of its developers, whose names are too numerous
 * to list here.  Please refer to the COPYRIGHT file distributed with this
 * source distribution.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

/* NOTE
 * Original source : http://labs.f0rked.com/xidle.c
 *
 * This program will disable logout prompt
 * logout after 30mins, and kill an apps which refuses to logout.
 * this application is unsupported. Use at your own risk.
 *
 * Build requirement : For RHEL4
 * GConf2-devel - for disabling logout prompt
 * gtk2-devel - for g_* functions
 * xorg-x11-devel - for Xss extension
 *  psmisc - for killall
 *
 * Compile using: g++ -o xidle xidle.c -L/usr/X11/lib/ -lXss  *   `pkg-config gconf-2.0 gtk+-x11-2.0  --libs --cflags` 
 *
 */

#include <X11/Xlib.h>
#include <X11/extensions/scrnsaver.h>

#include <gdk/gdkx.h>
#include <gtk/gtk.h>
#include <gconf/gconf-client.h>

#include <stdlib.h>


/* in seconds  */
const guint32 xidle_action_timeout=1800;
/* logout sequence for gnome */
const gchar xidle_action_execute[]=  
  "/usr/bin/gnome-session-save --kill"
  ";sleep 5"
  ";killall metacity-dialog";

static XScreenSaverInfo *mit_info = NULL;

void
gnome_logout (void)
{
 /* Set logout prompt to false, to enable automagic logout  */
 GConfClient *client = gconf_client_get_default ();
 const gchar key[] = "/apps/gnome-session/options/logout_prompt";

 gconf_client_set_bool (client, key, FALSE, NULL);
 g_object_unref (client);

 /* Logout */
 gtk_main_quit ();
 system (xidle_action_execute);
}

gboolean check_idle(gpointer *data)
{
 /* Check how long system has been idle */
 XScreenSaverQueryInfo (GDK_DISPLAY (), GDK_ROOT_WINDOW (),

          mit_info);

 float seconds = (float) mit_info->idle / 1000;

 g_message ("Idle for: %f\n", seconds);
 if (seconds > xidle_action_timeout){

  gnome_logout(); 
  return FALSE;
 }
 
 return TRUE;
}


int
main (int argc, char **argv)
{
 gtk_init (&argc, &argv);
 gconf_init (argc, argv, NULL);

 int event_base, error_base;
 if (!XScreenSaverQueryExtension(GDK_DISPLAY (), &event_base, &error_base))
 {
  g_error ("Error: XScreenSaver Extension not present\n");

  return -1;
 }

 mit_info = XScreenSaverAllocInfo (); 
 g_timeout_add(500,check_idle,NULL);

 gtk_main ();
 return 0;
}