Hi alex!

I have been a bit busy, so I did not see this yet. But now I did :)

Have you thought about piping the changes directly to the stdin of the change command process?
This would have the benefit of not needing to create a file, but could be a bit harder to use I guess.

And more generally do you intend to write the change file all the time, or just when ON_CHANGE_COMMAND is set?

Have you thought about piping the changes directly to the stdin of the change command process? This would have the benefit of not needing to create a file, but could be a bit harder to use I guess.

That's a great idea. I'll see if it's feasible.

And more generally do you intend to write the change file all the time, or just when ON_CHANGE_COMMAND is set?

That could be done; a pattern of file names / directory would need to be set to allow the user to poll / notify.