Ubuntu - Mouse - Map Mouse Buttons

In most cases,

Buttons 1, 2, 3 are interpreted as left, middle, right.
Logical buttons 4, 5, 6, 7 are usually interpreted as scroll up, down, left, right.
The fourth and fifth physical buttons on a device will thus send logical buttons 8 and 9.

Map a Mouse Button to Another Button

This can be useful for changing the mouse for left-handed people.

xinput set-button-map 8 3 2 1 4 5 6 7 8 9

NOTE: The initial 8 is the Mouse Id as determined above.

Usually this would be in the order 1 2 3, where
- 1: is the left mouse button.
- 2: is the middle mouse button.
- 3: is the right mouse button.

Here, button 3 is swapped with button 1.
- This means that when the actual left button on the mouse is clicked it results in a right-click.
- Also, clicking on the actual right mouse button results in a left-click.

xinput set-button-map 8 1 0 3 4 5 6 7 8 9

NOTE: The initial 8 is the Mouse Id as determined above.

One approach is to create a shell script that performs the Mouse Button mapping:

echo "xinput --set-button-map 21 3 2 1" > leftmouseremap.sh

Give it executable permission:

chmod +x leftmouseremap.sh

NOTE: Either run the script manually, or configure it to automatically run on system reboot.

Remember to configure 'xbindkeys' to run automatically on system startup too if needed:
- '/usr/bin/xbindkeys'