How you can manage the i3 window manager on multiple computers

Posted on 2020-03-21.

In this tutorial I'll show you a simple way you can manage the configuration of i3 across multiple computers with different setups on each computer.

i3 is my favorite window manager and while I appreciate the simplicity of both dwm and bspwm I very much prefer both the amazing layout capabilities and the build-in bar in i3.

One of the downsides of i3 however is that its configuration file isn't scriptable and if you run it on multiple computers with different setups, such as a desktop with a dual monitor setup and a laptop, you have to maintain multiple configuration files.

However, there is a simple way you can get around that.

I use a shell script that contains all the different configuration options. I never touch the i3 configuration file manually, instead I change the options in the shell script and run that. The shell script generates the i3 config file and it has conditions that determine what options to use based on the hostname.

Below is an example of such a shell script. Rather than echoing out every configuration line to the i3 config file, I concatenate all the options in a variable and add a newline. There are several way you can do that, but I prefer the method below. The shell script strives to be POSIX.

Please note that you can make many improvements to the script below, such as putting color codes into variables, remove some of the DRY , improve settings, etc., but I have listed it like this to serve as an example for inspiration.

#!/bin/sh
#
# This script generates the i3 config file (v4)

cfg_file="$HOME/.config/i3/config"
hostname=$(hostname)

if [ -d $HOME/.config/i3 ]; then
    # Let's clean up.
    rm $HOME/.config/i3/*
else
    mkdir -pv $HOME/.config/i3
fi

options='# i3 config'"\n"
options="$options"'set $mod Mod4'"\n"
options="$options"'font pango:DejaVu Sans Mono 8'"\n"
options="$options"'floating_modifier $mod'"\n"

# Disable focus following the mouse.
options="$options"'focus_follows_mouse no'"\n"

# Kill focused window.
options="$options"'bindsym $mod+Shift+q kill'"\n"

# Chance focus.
options="$options"'bindsym $mod+h focus left'"\n"
options="$options"'bindsym $mod+j focus down'"\n"
options="$options"'bindsym $mod+k focus up'"\n"
options="$options"'bindsym $mod+l focus right'"\n"

# Move focused window.
options="$options"'bindsym $mod+Shift+h move left'"\n"
options="$options"'bindsym $mod+Shift+j move down'"\n"
options="$options"'bindsym $mod+Shift+k move up'"\n"
options="$options"'bindsym $mod+Shift+l move right'"\n"

# Split in horizontal orientation.
options="$options"'bindsym $mod+Shift+h split h'"\n"

# Split in vertical orientation.
options="$options"'bindsym $mod+Shift+v split v'"\n"

# Enter fullscreen mode for the focused container.
options="$options"'bindsym $mod+Shift+f fullscreen toggle'"\n"

# Change container layout (stacked, tabbed, toggle split).
options="$options"'bindsym $mod+Shift+s layout stacking'"\n"
options="$options"'bindsym $mod+Shift+t layout tabbed'"\n"
options="$options"'bindsym $mod+Shift+e layout toggle split'"\n"

# Toggle tiling / floating.
options="$options"'bindsym $mod+Shift+space floating toggle'"\n"

# Change focus between tiling / floating windows.
options="$options"'bindsym $mod+space focus mode_toggle'"\n"

# Focus the parent container.
#bindsym $mod+a focus parent

# Focus the child container.
#bindsym $mod+d focus child

# Switch to workspace.
options="$options"'bindsym $mod+1 workspace 1'"\n"
options="$options"'bindsym $mod+2 workspace 2'"\n"
options="$options"'bindsym $mod+3 workspace 3'"\n"
options="$options"'bindsym $mod+4 workspace 4'"\n"
options="$options"'bindsym $mod+5 workspace 5'"\n"
options="$options"'bindsym $mod+6 workspace 6'"\n"
options="$options"'bindsym $mod+7 workspace 7'"\n"
options="$options"'bindsym $mod+8 workspace 8'"\n"
options="$options"'bindsym $mod+9 workspace 9'"\n"
options="$options"'bindsym $mod+0 workspace 10'"\n"

# Move focused container to workspace.
options="$options"'bindsym $mod+Shift+1 move container to workspace 1'"\n"
options="$options"'bindsym $mod+Shift+2 move container to workspace 2'"\n"
options="$options"'bindsym $mod+Shift+3 move container to workspace 3'"\n"
options="$options"'bindsym $mod+Shift+4 move container to workspace 4'"\n"
options="$options"'bindsym $mod+Shift+5 move container to workspace 5'"\n"
options="$options"'bindsym $mod+Shift+6 move container to workspace 6'"\n"
options="$options"'bindsym $mod+Shift+7 move container to workspace 7'"\n"
options="$options"'bindsym $mod+Shift+8 move container to workspace 8'"\n"
options="$options"'bindsym $mod+Shift+9 move container to workspace 9'"\n"
options="$options"'bindsym $mod+Shift+0 move container to workspace 10'"\n"

# For the box running with i3-gaps.
if [ "$hostname" = 'foo' ]; then
    options="$options"'gaps inner 10'"\n"
    options="$options"'gaps outer 0'"\n"
fi

# Disable title bars.
options="$options"'for_window [class="^.*"] border pixel 1'"\n"

options="$options"'bindsym $mod+d exec dmenu_run -i -l 20'"\n"
options="$options"'bindsym $mod+Return exec xterm'"\n"
options="$options"'bindsym $mod+c exec claws-mail'"\n"
options="$options"'bindsym $mod+f exec firefox'"\n"
options="$options"'bindsym $mod+g exec gimp'"\n"
options="$options"'bindsym $mod+h exec hexchat'"\n"
options="$options"'bindsym $mod+z exec filezilla'"\n"

# Custom scripts.
options="$options"'bindsym $mod+F9 exec --no-startup-id f9menu'
options="$options"'bindsym $mod+F10 exec --no-startup-id f10menu'"\n"
options="$options"'bindsym $mod+F12 exec --no-startup-id gnome-screenshot -i'"\n"

# Assign to floating by default.
options="$options"'for_window [class="mpv"] floating enable'"\n"

# Let's try to get most pop-up floating.
options="$options"'for_window [window_role="pop-up"] floating enable'"\n"
options="$options"'for_window [window_role="bubble"] floating enable'"\n"
options="$options"'for_window [window_role="task_dialog"] floating enable'"\n"
options="$options"'for_window [window_role="Preferences"] floating enable'"\n"
options="$options"'for_window [window_type="dialog"] floating enable'"\n"
options="$options"'for_window [window_type="menu"] floating enable'"\n"

# Reload the configuration file.
options="$options"'bindsym $mod+Shift+w reload'"\n"

# Restart i3 inplace (preserves your layout/session, can be used to upgrade i3).
options="$options"'bindsym $mod+Shift+Escape restart'"\n"

# Resize window (you can also use the mouse for that).
options="$options"'mode 'resize' {'"\n"
options="$options"'    bindsym h resize shrink width 10 px or 10 ppt'"\n"
options="$options"'    bindsym j resize grow height 10 px or 10 ppt'"\n"
options="$options"'    bindsym k resize shrink height 10 px or 10 ppt'"\n"
options="$options"'    bindsym l resize grow width 10 px or 10 ppt'"\n"

# Back to normal: Enter or Escape.
options="$options"'    bindsym Return mode "default"'"\n"
options="$options"'    bindsym Escape mode "default"'"\n"
options="$options"'}'"\n"

options="$options"'bindsym $mod+Shift+r mode resize'"\n"

if [ "$hostname" = 'foo' ]; then
    # Place workspace.
    options="$options"'workspace 1 output hdmi1'"\n"
    options="$options"'workspace 2 output hdmi2'"\n"

    options="$options"'bar {'"\n"
    options="$options"'    output hdmi1'"\n"
    options="$options"'    position top'"\n"
    options="$options"'    colors {'"\n"
    options="$options"'        background #1e1e1e'"\n"
    options="$options"'        statusline #aaaaaa'"\n"
    options="$options"'        separator  #555555'"\n"
    options="$options"'        focused_workspace  #008fff #007fff #ffffff'"\n"
    options="$options"'        active_workspace   #333333 #5f676a #ffffff'"\n"
    options="$options"'        inactive_workspace #333333 #222222 #888888'"\n"
    options="$options"'        urgent_workspace   #aa0000 #990000 #ffffff'"\n"
    options="$options"'    }'"\n"
    options="$options"'}'"\n"

    options="$options"'bar {'"\n"
    options="$options"'    output hdmi2'"\n"
    options="$options"'    position top'"\n"
    options="$options"'    colors {'"\n"
    options="$options"'        background #1e1e1e'"\n"
    options="$options"'        statusline #aaaaaa'"\n"
    options="$options"'        separator  #555555'"\n"
    options="$options"'        focused_workspace  #008fff #007fff #ffffff'"\n"
    options="$options"'        active_workspace   #333333 #5f676a #ffffff'"\n"
    options="$options"'        inactive_workspace #333333 #222222 #888888'"\n"
    options="$options"'        urgent_workspace   #aa0000 #990000 #ffffff'"\n"
    options="$options"'    }'"\n"
    options="$options"'    status_command i3blocks -c ~/.config/i3blocks.conf'"\n"
    options="$options"'}'"\n"
else
    options="$options"'bar {'"\n"
    options="$options"'    position top'"\n"
    options="$options"'    colors {'"\n"
    options="$options"'        background #1e1e1e'"\n"
    options="$options"'        statusline #aaaaaa'"\n"
    options="$options"'        separator  #555555'"\n"
    options="$options"'        focused_workspace  #008fff #007fff #ffffff'"\n"
    options="$options"'        active_workspace   #333333 #5f676a #ffffff'"\n"
    options="$options"'        inactive_workspace #333333 #222222 #888888'"\n"
    options="$options"'        urgent_workspace   #aa0000 #990000 #ffffff'"\n"
    options="$options"'    }'"\n"
    options="$options"'    status_command i3blocks -c ~/.config/i3blocks.conf'"\n"
    options="$options"'}'"\n"
fi

printf "$options" > $cfg_file
if [ -f $cfg_file ]; then
    echo "Created i3 config file"
else
    echo "Could not write config file"
fi

That's it! Feel free to email me any suggestions, correction, or comments.