Backlight Control

Simple program to control backlight brightness of laptops in Linux.

troglobit@example:~$ backlight -h

Usage: backlight [options] [command]

Options:
 -h    This help text
 -v    Show program version

Commands:
 up    Increase brightness
 down  Decrease brightness

Bug report address: https://github.com/troglobit/backlight/issues

The program has only two commands: up and down, which adjusts the brightness up or down, respectively. Without arguments the current (raw) brightness value read from /sys/class/backlight/*/brightness is displayed.

Brightness is controlled using an exponential scale to provide a smooth transition from max to min.

Build & Install

This is a GNU configure based project, so unless you are building it directly from GIT, you can:

./configure
make
sudo make install
sudo adduser $LOGNAME video

The install phase adds the required 90-backlight.rules to udev so that the system grants write privileges to members of the video group to control the display backlight. For the changes to take effect you have to reboot the system.

Note: if you are building from GIT, you have to manually create the configure script and Makefile.in file: ./autogen.sh helps you but you have to have the autoconf and automake tools installed.

Setup in Awesome

Users of the Awesome WM can update their ~/.config/awesome/rc.lua to include the following:

    -- Brightness
    awful.key({ }, "XF86MonBrightnessUp", function () os.execute("backlight up") end,
              {description = "Increase brightness", group = "hotkeys"}),
    awful.key({ }, "XF86MonBrightnessDown", function () os.execute("backlight down") end,
              {description = "Decrease brightness", group = "hotkeys"}),

Reload Awesome and your brightness keys will now work as expected.