Changing Between Window Managers Without a Display Manager

This is my BTW moment. I use Debian with dwm, without any desktop environment. I don’t want to change, but if I want to experiment, it can be annoying without a Display Manager.

There is a good chance that you live a well-adjusted life and don’t know what half of these words mean.

• Window Manager: The program that manages the windows on your screen. It’s responsible for drawing the borders, moving the windows, etc.
• Display Manager: A very bad name for a login screen.

Display Managers come with a Desktop Environment. Speaking of which:

• Desktop Environment: A collection of programs that work together to provide a consistent user experience. It includes a Window Manager, a File Manager, a Panel, etc.

The main thing is that Display Managers have the capability to switch between Desktop Environments and Window Managers.

How My Current Setup Works

I log in on a tty, and if that is tty1, startx command runs automatically. This starts the X server (display server) and runs the ~/.xinitrc script. This script starts dwm. Then dwm starts the other programs that are needed for a functional graphical environment.

TTY1 -> X server -> dwm -> programs

The important thing to understand here is that the X server is started with one config which starts a Window Manager. If I want to change the Window Manager, I need to restart the X server with a different config.

Handling Multiple Window Managers

One way is to have different configs for different Window Managers. For example, I can have ~/.xinitrc-dwm and ~/.xinitrc-i3. Then I can run startx ~/.xinitrc-i3 to start i3.

I don’t have a huge problem with this, but I still prefer to handle this in one configuration file, which keeps the standard ~/.xinitrc file.

Since the contents of ~/.xinitrc are just shell commands, I can use a shell case statement to select the Window Manager.

session=${1:-dwm}

case $session in
    dwm) exec dwm ;;
    i3) exec i3 ;;
    *) exec $1 ;;
esac

This way startx can be run without any arguments to start dwm, or with an argument to start another Window Manager, like startx "$HOME"/.xinitrc i3.

This is a really simple way to run different Window Managers in different tty’s if I want to experiment with them.

Thank you for reading this quickie, don’t prepare for longer content!