DEV Community

Bo
Bo

Posted on

Remap keys in the keyboard in Ubuntu

We could use xmodmap to remap keys in ubuntu.

First, generate the current keycode map:

xmodmap -pke > .Xmodmap
Enter fullscreen mode Exit fullscreen mode

Then open the .Xmodmap file, find the key you want to remap. In my case, the PageUp key is too close to the left arrow key and the PageDown key is too close to the right arrow key. Many times when I want to press the left arrow key, I pressed the PageUp key by accident. And I barely use the PageUp and PageDown key, so I want to remap the PageUp to LeftArrow and PageDown to RightArrow.

Once you open the .Xmodmap file, you will see a list of keycode and their functions, for example:

keycode  38 = a A a A
Enter fullscreen mode Exit fullscreen mode

And it is easy to find the keycode for the LeftArrow and RightArrow keys:

keycode  83 = KP_Left KP_4 KP_Left KP_4
keycode  85 = KP_Right KP_6 KP_Right KP_6
Enter fullscreen mode Exit fullscreen mode

But I don't know the keycode for the PageUp and PageDown key, so I need to find that first.

To detect what the keycode is for specific key, use command:

$ xev -event keyboard
Enter fullscreen mode Exit fullscreen mode

In my system, when I press PageUp, it shows 112:
Alt Text

So we can find that in the .Xmodmap file:

keycode 112 = Prior NoSymbol Prior
keycode 117 = Next NoSymbol Next
Enter fullscreen mode Exit fullscreen mode

Now to remap those keys, we just need to change them to the Left and Right arrow:

keycode 112 = KP_Left KP_4 KP_Left KP_4
keycode 117 = KP_Right KP_6 KP_Right KP_6
Enter fullscreen mode Exit fullscreen mode

Now save the file, and activate the key map:

$ xmodmap .Xmodmap
Enter fullscreen mode Exit fullscreen mode

Now if you press the "PageUp" key, it will work like the LeftArrow key.

But this change will only work in this login session. After you reboot the system, the keyboard will be reset to the default keys. To make it work on every reboot, we need to set an command to the "Startup Application":

$ xmodmap .Xmodmap
$ xkbcomp $DISPLAY $HOME/.xkbmap
Enter fullscreen mode Exit fullscreen mode

Now open "Startup Application":
Alt Text

Click Add, set name to "Remap Keys", and the command to:

xkbcomp /home/user/.xkbmap ":0"
Enter fullscreen mode Exit fullscreen mode

Make sure you replace the user above to your username. Then reboot your system, the remap should work on next boot.

Reference

Discussion (9)

Collapse
thefluxapex profile image
Ian Pride • Edited on

Nice, you can also use the xdotool/AutoKey combo which I've been using for many years and have been planning a tutorial for it.
Actually it'll be for window management as well with wmctrl.
I'll also be doing one on AutoHotkey in Windows.

Collapse
xaander1 profile image
Alexander

Saved my day. Had keys that had stopped working.

Collapse
henriquepgomide profile image
Henrique Gomide

Just loved your tutorial!

Collapse
mulleresposito profile image
Müller Esposito Nunes

Hello, I can get to remap colon and semicolon keys to same key?

Collapse
velcrine profile image
velcrine

yes you can

Collapse
mulleresposito profile image
Müller Esposito Nunes

When I done the steps from that tutorial my Ubuntu didn't booting. I had to change the modifications that I made via the safe mode boot.

Thread Thread
velcrine profile image
velcrine

Well i do it this way:
Assigned hyphen, to another key. Only this. Now, normal key press prints hyphen + when I shift press that key, I get underscore too.
Right now _ - I just typed using those keys.
Better to try and test, before making them permanent.

Collapse
sefatanam profile image
Sefat Anam

million dollar's article, man !

Collapse
vuducvi1999 profile image
Vuducvi1999

I just have only one thing to say: Thank you so much!