Humble Collection of i3wm Lifehacks: Part I

Lifehack 1: Locking the Screen

This is kinda a nobrainer, but me myself sometimes look for a place, where to copy some of the syntax (I’m lazy and don’t always keep that in my head), so let’s start with this one. i3wm ships with beautiful and robust screen locker i3lock, which can be launched like that:

i3lock -c 000000

It will lock the screen with black overlay. The problem is, that you wouldn’t be typing this command every time you want to lock the screen. We need to add a shortcut to i3 config file:

bindsym $mod+Shift+Tab exec "i3lock -c 000000"

Now when we press the combination of mod-button (Win in my case) and Shift+Tab – our screen gets locked.

Lifehack 2: Activating/Disactivating the Second Screen

If you use i3wm on daily basis, you probably know, that the second screen is not turned on automatically. You should manage displays manually with xrandr command. If we run this command without attributes, we’re gonna get something like this:

Screen 0: minimum 320 x 200, current 3200 x 1080, maximum 8192 x 8192
LVDS1 connected 1280x800+1920+0 (normal left inverted right x axis y axis) 261mm x 163mm
   1280x800      60.02*+  50.05  
   1024x768      60.00  
   800x600       60.32    56.25  
   640x480       59.94  
VGA1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 521mm x 293mm
   1920x1080     60.00*+
   1680x1050     59.95  
   1280x1024     75.02    60.02  
   1440x900      59.89  
   1280x960      60.00  
   1280x720      59.97  
   1024x768      75.08    70.07    60.00  
   832x624       74.55  
   800x600       72.19    75.00    60.32    56.25  
   640x480       75.00    72.81    66.67    60.00  
   720x400       70.08  
HDMI1 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)

On some rare occasion writing something like this would not be a problem:

xrandr --output VGA1 --right-of LVDS1 --auto

Well, I know you’re probably well aware of how xrandr works. Just in case.

It may get pretty redundant if you use second screen on daily basis and regularly unplug it from your laptop. The best way to go would be to add script shortcut to your /usr/bin/ or /bin/ directory. Run the following lines:

printf '#!/bin/bash\n\nxrandr --output VGA1 --right-of LVDS1 --auto' > /usr/bin/screenswitch
chmod 755 /usr/bin/screenswitch

We can use screenswitch command which doesn’t make it much easier. What would certainly help us is a key shortcut, so let’s add a line similar to one in the previous hack to our i3 configuration:

bindsym XF86Display exec "screenswitch"

Now when you press on your special key combo (Fn+F7 on my ThinkPad), you enable/disable the second screen. Try some other key combination if you have no special display button. Of course the script itself is pretty basic and it would work only if your screen works well in auto and you use the same second screen daily. However, there are more complex scripts available all over the web (example).

Lifehack 3: Locking the Screen on Wake

If you use pm-utils with your i3wm setup, you’ve probably noticed that the screen is not locked, when the laptop is awakened after suspend or hibernate. It’s very insecure. Let’s try to fix it. Create file cat /etc/pm/sleep.d/91blocker and add the following lines to it:

case "$1" in
                su youruser -c '/usr/bin/i3lock -c 000000'
        *) exit $NA

Don’t forget to change youruser to your username. Now let’s make sure we have all the right permissions:

chmod 755 /etc/pm/sleep.d/91blocker

Now, if we run pm-suspend or pm-hibernate our screen is going to be locked on wake. This script has one shortcoming though: it doesn’t lock the screen instantly, so you may see stuff for a couple of seconds before it gets locked. If it is not a critical issue to you, feel free to use it, othrewise you may need to work on it or find a different solution altogether. If you have any ideas how to improve it, let me know.


2 thoughts on “Humble Collection of i3wm Lifehacks: Part I

  1. memLeak says:

    Thanks, i completely forgot about the i3lock!
    you might want to use the default control + alt + L though (which is pretty much the standart shortcut for locking the screen on all systems)

    1. Yeah, control + alt + L is default for most systems, it’s just that my IDE overshadows it for its shortcuts and I kinda got used to win+Shift+Tab. Still it’s completely subjective, isn’t it.

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