Lumeus is a simple command line utility for Linux to adjust screen backlight brightness. It's useful for binding to a hotkey but it can also be used manually. It doesn't rely on X11 so it can be used in Wayland and system console.

Package lumeus-git is available in AUR.

$ git clone https://github.com/siiptuo/lumeus.git
$ cd lumeus
$ make
$ sudo make install

Running the command lumeus outputs the current brightness as percentage.

Adjusting the brightness can be done by giving the command a value. For example lumeus +10% increases the brightness by 10 percent. To decrease the brightness naturally use a minus sign instead. By omitting the sign altogether, the brightness is set to percentage of maximum brightness.

It's also possible to use an exact hardware brightness value simply by dropping the percentage sign and using plain integers. This is useful if the backlight brightness range is small like 0-15.

MIT