Gnome: Map AltGr key to Alt

Question

I have an annoying UK keyboard which has an Alt Gr key where the right Alt key is on a US keyboard. This is really annoying when using Gnome which makes heavy use of the Alt/Meta key.

Does anyone know how I can map the Alt Gr key to the Alt key?

Solution 1

xmodmap

The 'shift, lock, control, modN' on the left are what X sees and cares about. The keysyms on the right map to them. Mode_switch is your AltGr key. Move it to join the others at mod1:

xmodmap -e 'clear mod5'
xmodmap -e 'add mod1 = Mode_switch'

Solution 2

gnome-tweak-tool lets you do this with a GUI:

Typing -> Key to choose 3rd level -> Right Alt key never chooses 3rd level

Solution 3

For those UK users still pulling their hairs out, this worked for me:

xmodmap -e "clear mod5"
xmodmap -e "keycode 108 = Alt_L"

Explanation: The first line removes the current behaviour of your AltGr (which is assigned to the mod5 modifier). The second takes the AltGr key (which on my keyboard produces a keycode of 108), and maps that to whatever keycode your Alt_L key is mapped to.

If you have no idea what is going on with keycodes and keysyms, I found this xmodmap introduction very useful.

Comments

[ChrisInCambo]

No that didn't work for me, fired up emacs and AltGr-v gives me “ instead of scrolling the page up as it would with alt-v.

[Walter Kiess]

Those specific commands didn't work, or looking at the output of 'xmodmap' and moving the keysym didn't work? You can use 'xev' to help with this: run it, mouse over the window, and press modded keys.

[ChrisInCambo]

The command worked and here is the output of the xmodmap: shift Shift_L (0x32), Shift_R (0x3e) lock Caps_Lock (0x42) control Control_L (0x25), Control_R (0x69) mod1 Alt_L (0x40), Meta_L (0xcd) mod2 Num_Lock (0x4d) mod3 mod4 Super_L (0xce), Hyper_L (0xcf) mod5 ISO_Level3_Shift (0x5c), Mode_switch (0xcb)

[ChrisInCambo]

Sorry for the mess, is seems like this site strips line breaks from comments.

[Walter Kiess]

That output shows that you haven't cleared mod5, and that you haven't added Mode_switch to mod1. xmodmap -e changes like this are temporal: you can blow them away with setxkbmap, for instance.

[ChrisInCambo]

Sorry there was a reboot between when I entered the commands and recorded the output of xmodmap, maybe the changes aren't persistent? Anyway I've entered the command again and now xmodmap look like this: shift Shift_L (0x32), Shift_R (0x3e) lock Caps_Lock (0x42) control Control_L (0x25), Control_R (0x69) mod1 Alt_L (0x40), Meta_L (0xcd), Mode_switch (0xcb) mod2 Num_Lock (0x4d) mod3 mod4 Super_L (0xce), Hyper_L (0xcf) mod5 So the changes are showing, but if I still can't do CTRL-ALT-DEL in Gnome or use meta commands in emacs using AltGr.

[Walter Kiess]

And if you also xmodmap -e 'add mod1 = ISO_Level3_Shift' ?

[ChrisInCambo]

Yes thanks alot, that nailed it! Are those changes persistent or will I loose them when I reboot?

[Walter Kiess]

They are not persistent. I've put them in ~/.xsession for xdm setups, but linuxtopia.org/online_books/linux_beginner_books/… suggests that you put them in ~/.gnomerc

[ChrisInCambo]

Ok I've now noticed a problem, gnome is behaving like the alt key is constantly pressed, when I hit v for example in nautilus it opens up the View menu.

[Walter Kiess]

If you're sure that this is related, you might: try removing the mode_switch keysym; change the keycode to generate Alt or Meta keysyms instead of dealing with the modifier table at all (xmodmap usage is similar: xmodmap -e 'keycode 123 = 4 5' -- look through xmodmap -pke)

[ChrisInCambo]

Ok cracked it with xmodmap -e 'keycode 203 = NoSymbol Meta_L NoSymbol Meta_L NoSymbol Meta_L'. If anyone else is trying this your key might not be 203, look for the key which calls Mode_switch and change it to the above.

[Vomit IT - Chunky Mess Style]

Link only answer say what??

[rubo77]

In German: "Verhalten der Alt/Windows-Tasten" -> "Alt und Meta befinden sich auf den Alt-Tasten"

[ACV]

This is working in Ubuntu 20.04 in year 2020 :)

[Naidim]

^ This is the best solution.

[ACV]

In Ubuntu 20.04 It is Tweaks -> Keyboard & Mouse -> Additional Layout Options

[Kyle Baker]

For non UK users: This worked on my german keyboard as well, while the gnome-tweaks setting did not fwiw. Ubuntu 20.10 variant (pop os).