I have recently moved from Cinnamon to i3, but my question is really more related to Cinnamon. In Cinnamon I was able to control my keyboard backlight via media keys on my laptop. Now that I am in i3, I have found the command and tried to bind the keys myself in the config file but it doesn’t work. Further digging, I discovered that I cannot even run the command manually… even using sudo, I get a permission denied error.

How does Cinnamon handle this? Where can I find the code so that I can port it to i3?