hspak / brightnessztl

A CLI to control device backlight

Brightnessztl

A CLI to control device backlight. It defaults to the intel_backlight class.

Setup

# development tracks the latest stable zig release (0.11.0)
zig build

Usage

brightnessztl <action> [action-options]

  Actions:
    get:    Display current brightness
    set:    Update the brightness
    debug:  Display backlight information
    help:   Display this

  Set options:
    X:       Increase brightness to X%
    +X:      Increase brightness by X%
    -X:      Decrease brightness by X%
    max:     Set brightness to maximum
    min:     Set brightness to minimum

By default, brightnessztl now links in libsystemd to leverage the D-Bus C API to allow setting backlight values without root permissions or udev rules. (h/t https://github.com/joachimschmidt557)

To disable this behavior, you can build via zig build -Dlogind=false. brightnessztl will require either root access or the following udev rules to run:

ACTION=="add", SUBSYSTEM=="backlight", KERNEL=="intel_backlight", RUN+="/bin/chgrp video /sys/class/backlight/%k/brightness"
ACTION=="add", SUBSYSTEM=="backlight", KERNEL=="intel_backlight", RUN+="/bin/chmod g+w /sys/class/backlight/%k/brightness"

Install

Available on Arch Linux via AUR

License

MIT