Program to manipulate screen brightness on Linux using sysfs.

backlight. Simple program to control your backlights.

Usage:
	backlight ls                    Lists all devices and their values
	backlight set <device> <val>    Sets the brightness of a device to a specific value
	backlight dec <device> <val>    Decreases the brightness of a device by a specific value
	backlight inc <device> <val>    Increases the brightness of a device by a specific value
	backlight help					Displays this help message :)

This program requires the cap_dac_override capability to modify brightness values in sysfs without running as root.

After installation, you must run:

sudo setcap cap_dac_override+ep /path/to/backlight

The program will warn you if this capability is not set when you try to modify brightness.

For x64 you can download and install the released binary with the following script.

wget https://github.com/Tethik/backlight/releases/latest/download/backlight
wget https://github.com/Tethik/backlight/releases/latest/download/backlight-completion.sh
chmod +x backlight
sudo mv backlight /usr/local/bin/backlight
sudo setcap cap_dac_override+ep /usr/local/bin/backlight
sudo mv backlight-completion.sh /etc/bash_completion.d/backlight

Requires that you have golang installed.

git clone https://github.com/Tethik/backlight
make
sudo make install

Why sudo? To allow the program access to sysfs from a normal user the install script sets cap_dac_override.

I originally built this for my own i3 setup. The following is the configuration I use to bind the brightness keys on my laptop to run this backlight program.

# Sreen brightness controls
bindsym XF86MonBrightnessUp exec backlight inc intel_backlight 50
bindsym XF86MonBrightnessDown exec backlight dec intel_backlight 50

nix profile add github:Tethik/backlight

Important: After installation, set the required capability:

sudo setcap cap_dac_override+ep $(readlink -f $(which backlight))

This allows the program to modify sysfs brightness values without requiring sudo for each use.