This guide is a quick explainer on how to add custom keyboard mappings to the standard US keyboard layout in Ubuntu 20.04/22.04 using left-alt as a layer key.
This is based on: https://help.ubuntu.com/community/Custom%20keyboard%20layout%20definitions?action=show&redirect=Howto%3A+Custom+keyboard+layout+definitions
There are two files to edit
- /usr/share/X11/xkb/symbols/us
- /usr/share/X11/xkb/rules/evdev.xml
In file “/usr/share/X11/xkb/symbols/us”:
After the first layout “basic” after line 57 and before the next layout add:
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partial alphanumeric_keys
xkb_symbols "custom" {
include "us(basic)"
name[Group1]= "English (US, euro on 5)";
key <AD07> { [ u, U, grave, asciitilde ] };
key <AD08> { [ i, I, minus, underscore ] };
key <AD09> { [ o, O, equal, plus ] };
key <AD10> { [ p, P, backslash, bar ] };
key <AC07> { [ j, J, Left, Left ] };
key <AC08> { [ k, K, Down, Down ] };
key <AC09> { [ l, L, Up, Up ] };
key <AC10> { [ semicolon, colon, Right, Right ] };
key <AB06> { [ n, N, bracketleft, braceleft ] };
key <AB07> { [ m, M, bracketright, braceright ] };
key <AB08> { [ comma, less, Home, Home ] };
key <AB09> { [ period, greater, End, End ] };
key <AB10> { [ slash, question, Delete, Delete ] };
key <AC11> { [ apostrophe, quotedbl, BackSpace, BackSpace ] };
include "level3(lalt_switch)"
};
In file “/usr/share/X11/xkb/rules/evdev.xml”:
Find (should be line 1334):
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<layoutList>
<layout>
<configItem>
<name>us</name>
<!-- Keyboard indicator for English layouts -->
<shortDescription>en</shortDescription>
<description>English (US)</description>
Before the “chr” variant, after the <variantList> line, add our own custom variant:
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<variant>
<configItem>
<name>custom</name>
<description>English (custom left alt layer)</description>
</configItem>
</variant>
In terminal (not confirmed if required)
Run
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sudo dpkg-reconfigure xkb-data
Reboot
Finally reboot after
Select keyboard and delete the default
In settings, go to keyboard tab.
Under “Input Sources” click the “+” button to add a new keyboard.
Select “English (United States)”.
Then scroll down to find the <description> provided in the evdev.xml file. In this case it’s “English (custom left alt layer)”.
Delete the default keyboard from “Input Sources” to let it take effect.