I know you're looking for a desktop solution, but here's something that you can try in case you can't find one -- I'm betting that having a solution is better than having none!

So I just had a quick muck around:

• You can use pgrep to detect if a process with a given name is running
• You can write to /dev/pts/0 to trigger a desktop notification
• You can drop it into a cron job to run it automatically on a schedule

As a test, the following command will look for a process called syncthing and send a desktop notification if it can't find it:

pgrep syncthing || echo "Syncthing is not running > /dev/pts/0"

To set up a cron job:

1. open a terminal
2. open the editor with crontab -e (if you need to pick an editor, nano will probably be your best bet, it's easiest to use)
3. in the editor, add the following line to the end of the file: 0 * * * * pgrep syncthing || echo "Syncthing is not running" > /dev/pts/0
   • The 0 * * * * sets up the schedule (on the 0th minute of every hour, every day of the month, every month, on every day of the week)
   • Everything after that is the command to run
4. save and quit

If you ever want to get rid of it, just open the cron file again (crontab -e) and remove the line.

I gave this a go on KDE under Wayland and it seems to do the trick. Good luck, I hope you find what you're looking for!

[edit-1] added step (2) to install libnotify-bin in case you don't have it already. [edit-2] added XDG_RUNTIME_DIR to step (4) [edit-3] removed references to libnotify, replace with /dev/pts/0 (Nice one, @sun_is_ra@sh.itjust.works !)

It doesn't work for me (using plasma). Also it seems to be using DBUS which I am not sure if it will work within a cron job.

A simple solution that works for me is something like this:

echo hello > /dev/pts/0