Enable killing X.org with a custom key combination

keyboard shortcutskillsettingsxorg

I've just read How to enable killing X.org with ctrl+alt+backspace and am really happy, that control–alt–backspace no longer kills my X-Server. However, I'd like to have a way to kill it. It just should be something more complicated than what I type by accident ten times a day.

Is there a way to define an custom binding for the kill-command?

I'd like to use control–alt–meta–shift–backspace or alike and from the line

 Option          "XkbOptions" "terminate:ctrl_alt_bksp"

it's not obvious how to do it (unless it is "terminate:ctrl_alt_meta_shift_bksp" which doesn't seem to work).

Best Answer

XkbOptions refers to a rule defined in the XKB rules file, normally /usr/share/X11/xkb/rules/base, which will look like:

terminate:ctrl_alt_bksp =   +terminate(ctrl_alt_bksp)

That in turn picks up the definition from the terminate symbols file, normally /usr/share/X11/xkb/symbols/terminate. I'm not sure if you can just add more modifiers to the type="CTRL+ALT" line there or if there's limits on the type value.

Documentation on XKB customization can be found at http://www.x.org/wiki/XKB and may be able to help fill in some of the gaps in this answer.

Related Solutions

Xorg – How to Enable Killing with Ctrl+Alt+Backspace

Modify /etc/X11/xorg.conf or a .conf file in /etc/X11/xorg.conf.d/ with the following. (note: it is ok if this is all you have in your xorg.conf as xorg will still auto-detect the rest (note: that is if auto-detect works for you without it))

Section "ServerFlags"
    Option "DontZap" "false"
EndSection

Section "InputClass"
    Identifier      "Keyboard Defaults"
    MatchIsKeyboard "yes"
    Option          "XkbOptions" "terminate:ctrl_alt_bksp"
EndSection

Keyboard – Mapping Key Combinations with Xmodmap

That's not possible with xmodmap. I don't think it's possible with XKB either, but I'm not sure.

Is your aim to have a key that's always identical to pressing Ctrl+C (e.g. in a terminal, it would interrupt the running program), or to have a clipboard copy key? If the latter, try

keycode 135 = XF86Copy

The XF86Copy keysym is intended for a copy-to-clipboard key, but I don't know how many applications have that shortcut out-of-the-box.

If you're on Ubuntu, and possibly even if you aren't, the recommended method to set up additional (“multimedia”) keys is keytouch.

If you really want the key to be equivalent to Ctrl+C, your desktop environment or window manager may let you bind the keysym to a command that generates key press and release events for that key combination. If you prefer or must use a DE/WM-agnostic method, you can use xbindkeys to bind an arbitrary shell command to a key, and xmacro to manufacture key events to send to a window. You'll still need to have a keysym associated with the key; a good choice is F13 (or wherever the numbered function keys on your keyboard leave off). Then put this in your ~/.xbindkeysrc:

"{ echo KeySymPress Control_L; echo KeySym C; echo KeySymRelease Control_L; } | xmacroplay"
  F13

You'll need to start xbindkeys with your X session — from your ~/.xinitrc or ~/.xsession if you have one, or from the appropriate configuration interface in your DE/WM.

Best Answer

Related Solutions

Xorg – How to Enable Killing with Ctrl+Alt+Backspace

Keyboard – Mapping Key Combinations with Xmodmap

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