How do I logout from a computer using shell?

How can I log out of my computer using shell such the log-in window appears again?

I need this functionality in one my Linux script.

Update: I want to replicate the 开发者_如何学Ccode working behind the Logout button of my Ubuntu.

Desktop Enviroment being used: GNOME

I think this does the job:

gnome-session-save --logout

Also, take a look at the --help output, maybe you want to use the --force-logout option.

Usage:
  gnome-session-save [OPTION...]

Help Options:
  -h, --help               Show help options
  --help-all               Show all help options
  --help-gtk               Show GTK+ Options

Application Options:
  --logout                 Log out
  --force-logout           Log out, ignoring any existing inhibitors
  --logout-dialog          Show logout dialog
  --shutdown-dialog        Show shutdown dialog
  --gui                    Use dialog boxes for errors
  --display=DISPLAY        X display to use

Your question is a bit vague. Are you trying to log out of a graphical session of a desktop environment (such as KDE/Gnome), as if the user clicked on "log off"?

Then you need to find out if/how the desktop environment supports scripting to log out. On KDE for example you can use kquitapp.

Try restarting the display manager using one of the following, depending one which one you're using. You'll obviously have to have the proper permissions.

/etc/init.d/xdm restart
/etc/init.d/kdm restart
/etc/init.d/gdm restart

It's a bit of a hack, but the way that screen's power detach does this is to determine its parent pid and send it a SIGHUP. (Clarification: This closes only the shell, so only works if you're running from a console - not a graphical login - so may not be what you're looking for.)

Type in terminal

gnome-session-quit

or

pkill -kill -u {Username}