The above said, it wasn’t hard to find a project using XDG and a JSON mapping file (basically your idea fleshed out in python) to get where you want to go if XDG is enough: https://github.com/JonTheNiceGuy/usbrowser

You’re not going to like this answer - there’s a bunch of different ways depending on the app(s) and the desktop environment. The Arch wiki goes over it in detail: https://wiki.archlinux.org/title/Default_applications

I would guess that focusing on the XDG spec and covering Gnome, KDE and Xfce (Xfce can be replaced with anything else like Cinnamon that comes with Mint, “non Gnome or KDE”) is the best plan of attack for what matters to 80%+ of the population.

So close! you have to do cat < foo.txt :-) (/s)

I would assume your system is using systemd (I don’t use Kubuntu specifically); the laptop lid is (now in 2026) controlled by the systemd infrastructure - it’s a matter of setting a config option and this should fix you up. Arch as usual has the best wiki on the subject:

https://wiki.archlinux.org/title/Power_management#ACPI_events

You’re probably looking at HandleLidSwitch* options. There’s still nothing wrong with the manual disable to /proc/acpi/wakeup to cover your bases (layers of the onion), I’m fighting with a “modern” laptop that only has s2idle and it’s terrible compared to S3 - I’m in ACPI wakeup hell and still trying to figure out what’s causing it.