How to enable/disable Ctrl+Alt+Backspace in Ubuntu 9.10 (Karmic)

Ctrl+Alt+Backspace (i.e. the shortcut which was used to restart the X
server) has to be enabled in a different way with respect to previous
releases of Ubuntu.

This is due to the fact that "DontZap" is no longer an option in the X
server and has become an option in XKB instead.

Using GNOME

* Get to the System->Preferences->Keyboard menu.

* Select the "Layouts" tab and click on the "Layout Options" button.

* Then select "Key sequence to kill the X server" and enable "Control +
Alt + Backspace".

Using KDE

* Launch "systemsettings"

* Select "Regional & Language".

* Select "Keyboard Layout".

* Click on "Enable keyboard layouts" (in the Layout tab).

* Select the "Advanced" tab. Then select "Key sequence to kill the X
server" and enable "Control + Alt + Backspace".

Using the command line

You can type the following command to enable Zapping immediately.

setxkbmap -option terminate:ctrl_alt_bksp

If you're happy with the new behaviour you can add that command to your
~/.xinitrc in order to make the change permanent.

Using HAL

You can add the following line
in /usr/share/hal/fdi/policy/10osvendor/10-x11-input.fdi (inside the
<match key="info.capabilities" contains="input.keys"> section):

<merge key="input.xkb.options"
type="string">terminate:ctrl_alt_bksp</merge>