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Brightness, volume control and other stuff in I3

Posted on 4 mins read

I have recently started using i3wm on a full-time basis. Previously, I have been using KDE plasma (checkout KDE connect if using KDE plasma).

This post is simply to share some of the common configs that one might need to add after booting into i3 for the first time. The settings for i3 configs are mostly found at ~/.config/i3/config, if not copy from /etc/i3/config.

Meta Key

I am using windows or host as Meta key. To do that simply set the required key to the $mod variable. In my case:

set $mod Mod4
Terminal

Default terminal is set to i3-sensible-terminal which is not sensible at all. I prefer konsole terminal from KDE. To change it:

bindsym $mod+return exec /usr/bin/konsole

Alternatively, you could also set the $TERMINAL variable.

Bar

I prefer the bar to be on top of screen. You can simply change that by doing*:

bar {
	position top
	status_command i3status
}

*create this block if doesn’t exist else edit existing block, unless you want to bars.

Volume Control

Volume keys doesn’t working in most cases. To identify the keycode of the volume button on your keyboard, use the xev command to get the content of X events. Use:

xev -event keyboard

Upon pressing the volume keys, we will get the keycodes. They are:

  • XF86AudioRaiseVolume
  • XF86AudioLowerVolume
  • XF86AudioMute

I am using amixer to change the volume. The configuration looks like this:

bindsym XF86AudioRaiseVolume exec amixer -q set Master 5%+ unmute
bindsym XF86AudioLowerVolume exec amixer -q set Master 5%- unmute
bindsym XF86AudioMute exec amixer -q set Master toggle
Brightness Control

Use xev again for finding the button keycodes for brightness control. Now check whether xbacklight is able to detect the drivers. If yes, then simply add the following to the i3 config file:

bindsym XF86MonBrightnessUp exec xbacklight -inc 20
bindsym XF86MonBrightnessDown exec xbacklight -dec 20

If not and you get something like “No outputs have backlight property”, then follow the instructions:

  • Find out the drivers for backlight that is present in your system with:

    sudo find /sys/ -type f -iname 'brightness'

This will give you a hint to the drivers you have. Mine was an intel_backlight(others can be acpi_video0) with symlink to /sys/class/backlight/intel_backlight/brightness.

  • Change file mod bits so that it can be writable. For that do:

    sudo chmod a+rw /sys/class/backlight/intel_backlight/brightness

  • Next, create a shell script with the content as following:

    #!/bin/bash

set -e
file="/sys/class/backlight/intel_backlight/brightness"
current=$(cat "$file")
new="$current"

if [ "$1" = "-inc" ]
then
	new=$(( current + $2 ))
fi

if [ "$1" = "-dec" ]
then
new=$(( current - $2 ))
fi

echo "$new" | tee "$file"

  • Then simply add the following to i3 config file:

    bindsym XF86MonBrightnessUp exec sh ~/.config/i3/backlight.sh -inc 20
bindsym XF86MonBrightnessDown exec sh ~/.config/i3/backlight.sh -dec 20

~/.config/i3/backlight.sh is path to the shell script shown earlier in my case.

Application shortcuts

You can set shortcuts for frequently used applications by doing something like:

bindsym $mod+c exec google-chrome
bindsym $mod+g exec geary

So, Meta+c will open Google Chrome and Meta+g will open Geary.

Shutdown, reboot, logout etc

The following sets Meta+Escape to give you a menu to select whether to lock, logout, suspend, hibernate, reboot, shutdown:

set $Locker i3lock && sleep 1

set $mode_system (l)lock  (e)logout  (s)suspend  (h)hibernate  (r)reboot  (Shift+s)shutdown
 
mode "$mode_system" {
	bindsym l exec --no-startup-id $Locker, mode "default"
	bindsym e exec --no-startup-id i3-msg exit, mode "default"
	bindsym s exec --no-startup-id $Locker && systemctl suspend, mode "default"
	bindsym h exec --no-startup-id $Locker && systemctl hibernate, mode "default"
	bindsym r exec --no-startup-id systemctl reboot, mode "default"
	bindsym Shift+s exec --no-startup-id systemctl poweroff -i, mode "default"

	# back to normal: Enter or Escape
	bindsym Return mode "default"
	bindsym Escape mode "default"
}

bindsym $mod+Escape mode "$mode_system"
Bonus: Xrandr

Check the connected display names and their settings using command xrandr --query.

In my case, they are eDP-1 for the laptop display and HDMI-1 or VGA-1 for external respectively.

Upon connecting external display you can use the following configurations:

set $mode_display Ext Screen (v) VGA ON, (h) HDMI ON, (x) VGA OFF, (y) HDMI OFF

mode "$mode_display" {
    bindsym v exec --no-startup-id xrandr --output VGA-1 --auto --right-of eDP-1, mode "default"
    bindsym h exec --no-startup-id xrandr --output HDMI-1 --auto --right-of eDP-1, mode "default"
    bindsym x exec --no-startup-id xrandr --output VGA-1 --auto --off, mode "default"
    bindsym y exec --no-startup-id xrandr --output HDMI-1 --auto --off, mode "default"

    # back to normal: Enter or Escape
    bindsym Return mode "default"
    bindsym Escape mode "default"
}

bindsym $mod+x mode "$mode_display"

You can change whether you want the display on left or right or same as that of eDP-1 depending on what your usecase is.

Resources: