switching caps-lock key into control key

There are couple of ways how to make your caps-lock key into control key. For some of use keyboard-shortcuts nerds keyboard usage optimisation is quite an important topic. One of useful things is to move (or rather add) a control (CTRL) key to the place where (rarely used) CAPS LOCK key is. This is especially usefull if one work in EMACS a lot. So, obviously emacs-wiki is a good source for various ways how to achieve that. See https://www.emacswiki.org/emacs/MovingTheCtrlKey for more. But specificaly in my case I used the following recipe for Debian and derivatives:

To make Caps Lock another Ctrl key, edit the file /etc/default/keyboard and change the line which reads


and then run:

Changes take effect on next login and seem to perpetuate across virtual terminals and X session.