LiLaSS: Linux Laptop Screen Setup


This is the documentation of LiLaSS, a tool to setup screens on a Linux-powered Laptop.

LiLaSS is targeted for a specific use-case: The laptop is used both with the internal screen only, and in combination with a single external screen. xrandr is used to detect whether an external screen is plugged in, and to change the configuration according to the user’s specification. Furthermore, LiLaSS remembers the configuration used for any particular screen, so that it can offer the same configuration next time. You can even make it apply that configuration automatically.


LiLaSS features an interactive and a batched mode of use. Either way, if LiLaSS is started while no external screen is connected, it enables the internal screen.

It is in the case that an external screen is plugged in that the two modes differ.

Simply run lilass to start the interactive mode. A window will pop up, allowing you to select which screens are enabled, their resolution, and how they are positioned relatively to each other. The option --frontend (or -f) can be used to choose the frontend which opens the window. Currently, the frontends qt (using Qt5), zenity and cli are available. LiLaSS attempts to choose an adequate frontend automatically.

If a screen is connected that was already configured with LiLaSS before, the previously selected configuration will be offered per default. You can pass --silent (-s) to instead suppress the UI altogether, and just apply the previous configuration. You can disable the use of the stored screen configurations by passing --no-db.

Furthermore, you can also suppress the UI in case LiLaSS sees a new screen by telling LiLaSS directly what to do with that screen: With the flags --internal-only (-i) and --external-only (-e), one of the two screens is picked and the other one disabled. With --relative-position (-r), the relative position of the two screens can be set (left, right, above, below or mirror). In either case, the preferred possible resolution(s) of the screen(s) will be picked if applicable. (In mirror mode, LiLaSS instead picks the largest resolution that both screens have in common.)

If the internal screen ends up being the only one that is used, LiLaSS attempts to turn on your backlight if it was disabled.

Automatic Configuration

In combination with x-on-resize by Keith Peckard, LiLaSS can be run automatically when a screen is plugged in, and automatically re-enable the internal screen the external one is plugged off. As LiLaSS remembers the screen configuration that was used last time, this automatic mode will use the previous configuration if the same screen is connected again.

All this is achieved by running the following on log-in:

x-on-resize --config "lilass -s -r mirror" --start

Of course, instead of -r mirror, you can pick a different default configuration applied to screens that have not been seen previously. By dropping this option altogether, LiLaSS will instead pop up and ask what to do when a new screen is connected.

Configuration File

You can use ~/.config/lilass.conf to tell LiLaSS which are the names of your internal and external connectors. These are the names as used by xrandr. The option internalConnector gives the name of the xrandr connector corresponding to your internal laptop screen. All the others will be considered external screens, unless you use the option externalConnectors to provide a (space-separated) list of connectors to be considered external by LiLaSS. Any connector not mentioned in either option will be completely ignored.

Source, License

You can find the sources in the git repository (also available on GitHub). They are provided under the GPLv2 or (at your option) any later version of the GPL. See the file LICENSE-GPL2 for more details.


If you found a bug, or want to leave a comment, please send me a mail. I’m also happy about pull requests :)