Swapping Ctrl and Alt keys on a GNU Debian system

Tested with Debian 7, 8, 9, and 10.

if you're a touch typist you might notice that you use the Ctrl key much more often than Alt, and stretching the finger to Alt feels a little uncomfortable. One tip you can use to mitigate the uncomfortable feeling is to press the Ctrl key with a side of your palm, giving that your keyboard has sufficiently big and protruding buttons.

When it's not the case, especially true with a laptop keyboard, programmatically swapping the keys might be something you'd give a try. This way you can comfortably reach the Ctrl buttons with your thumbs.

For TTY

Reminder: you normally enter TTY when pressing the Alt-Ctrl-1 combination

First you need to create a regular text file that will hold the key mappings and fill it with the following contents:

keymaps 0-127

keycode 56  = Control  ! left alt to ctrl.
keycode 100 = Control  ! right alt to ctrl.
keycode 29  = Alt      ! left ctrl to alt.
keycode 97  = Alt      ! right ctrl to alt.

When you've done, save it on your system where you see fit, in my example it is in the /home/user/.config directory. I named the file Alt2Ctrl_TTY.map

To do the swapping run the following command:

sudo loadkeys $HOME/.config/Alt2Ctrl_TTY.map

Note that after rebooting your machine the functions of the Alt and Ctrl keys will be restored to the original state.

For the X Window System - X11 (GUI)

Also works for terminal emulators opened in X11

A similar procedure is used with the X Window System, create a file and put this into it:

clear control 
clear mod1 

keycode 37  = Alt_L Meta_L 
keycode 105 = Alt_R Meta_R 
keycode 64  = Control_L 
keycode 108 = Control_R 

add control = Control_L Control_R 
add mod1    = Alt_L Meta_L

I've saved my file using this path: /home/user/.config/Alt2Ctrl_GUI.xmap

Run swapping by executing the following command, adjusting the filename or path if necessary:

xmodmap $HOME/.config/Alt2Ctrl_GUI.xmap

The http://xahlee.info/linux/linux_swap_control_and_alt_xmodmap.html web page was a source of my knowledge in this area some years ago.

With the xmodmap for X11 there's no need to be a superuser or use sudo.

As with TTY, after rebooting, the key functions will be restored to the original state.

Making the Remapping Convenient

Writing a shell function to encompass the swapping commands


swap-alt-and-ctrl-keys () {
	xmodmap $HOME/.config/Alt2Ctrl_GUI.xmap
	sudo loadkeys $HOME/.config/Alt2Ctrl_TTY.map 2>/dev/null
}

Note that this function can remap both TTY and X11 in one go only when being run under the X Window System.

Swapping Ctrl and Alt keys on a GNU Debian system

This page was last updated on March 14, 2021