i3 - screen brightness control

i3 hack for screen brightness control

June 20, 2020 · GNU/Linux OS i3

i3: screen brightness control

i3 is improved tiling window manager. Its FOSS and targeted to advanced user and developer community. It uses xcb (The X protocol C-language Binding) than xlib. Details can be found at https://i3wm.org/

Screen brightness:

There are on keyboard special function keys which control brightness and on heavier window managers these things are auto configured but on i3 we need to configure it. One way to control screen brightness on Intel based systems is by updating `/sys/class` file

echo "<num>" > /sys/class/backlight/intel\_backlight/brightness

scripts

upbrightness

$ which upbrightness

/usr/bin/upbrightness

$ cat /usr/bin/upbrightness

#!bin/bash
set -x
id
max=\`cat /sys/class/backlight/intel\_backlight/max\_brightness\`
current=\`cat /sys/class/backlight/intel\_backlight/brightness\`
newCurrent=$(($current + 50))
if \[ $current -eq $max \]
then
    exit
fi
if \[ $newCurrent -gt $max \]
then
    newCurrent=$max
fi
echo $newCurrent > /sys/class/backlight/intel\_backlight/brightness

downbrightness

$ which downbrightness

/usr/bin/downbrightness

$ cat /usr/bin/downbrightness

#!/bin/bash
set -x
id
min=50
current=\`cat /sys/class/backlight/intel\_backlight/brightness\`
newCurrent=$(($current - 50))
if \[ $current -eq $min \]
then
    exit
fi
if \[ $newCurrent -lt $min \]
then
    newCurrent=$min
fi
echo $newCurrent > /sys/class/backlight/intel\_backlight/brightness

Add sudo access

$ cat /etc/sudoers | grep down

<user> ALL=NOPASSWD:/usr/bin/upbrightness,/usr/bin/downbrightness

Configure i3 key bindings

$ cat ~/.config/i3/config | grep brigh

bindsym XF86MonBrightnessUp exec sudo upbrightness
bindsym XF86MonBrightnessDown exec sudo downbrightness