backlight

backlight is a simple python module for changing the keyboard or monitor backlight brightness. it ships with a command line utility for changing the brightness from your terminal.

$ backlight-cli --decrease monitor
monitor brightness has been set to 12000
$ backlight-cli --increase keyboard
keyboard brightness has been set to 25
$ backlight-cli --help
usage: backlight-cli [-h] [-i] [-d] [-g] {keyboard,monitor}

changes the backlight brightness

positional arguments:
  {keyboard,monitor}

optional arguments:
  -h, --help          show this help message and exit
  -i, --increase
  -d, --decrease
  -g, --get_current

installing

clone the repo and run:

• python setup.py test
• python setup.py install

if the tests do not pass, there is most likely a permission error addressed later in this readme.

creating backlight objects

the backlight interface is very simple and all backlights can inherit from the Backlight class by providing the path to your backlight hardware (on arch linux this is /sys/class/backlight or /sys/class/led for keyboards), and optionally the name of the device (the default behavior is to attempt to autodiscover a device).

allowing non-root users to change the backlight value

by default (in the linux environment) the values of a backlight are only changable by the root user. enabling users to control the backlight on Arch Linux using systemctl requires a service similar to the following

# /usr/lib/systemd/system/gmux-monitor-backlight.service
# systemctl enable gmux-monitor-backlight.service

[Unit]
Description=Gmux Monitor Backlight
Wants=systemd-backlight@backlight:gmux_monitor.service
After=systemd-backlight@backlight:gmux_monitor.service

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/bin/chmod 666 /sys/class/backlight/gmux_backlight/brightness

[Install]
WantedBy=multi-user.target

on other platforms /bin/chmod 666 /sys/class/backlight/gmux_backlight/brightness should do the trick