How to start a job, do something different, and resume it again

Question

I want to start a web server via Python. When this succeeds, I want to open the page in the default browser (on macOS, you can do this with the open command), and after that, I want to resume the previous script again.

This does not work:

#!/usr/bin/env bash
cd wwwroot
python3 -m http.server &
open http://0.0.0.0:8000
fg 1

I could not use jobs, and open the URL, and after that just run the Python script. However, I don't want to reload the page of the URL. Python will continue to run, until stopped by Ctrl+C.

Perhaps, the open command needs to have a sleep command when Python is not ready yet...

Answer 1

After some experimentation, it seems that $! is the variable you want. Example:

(sleep 1 && open http://0.0.0.0:8000) &
disown $!
python3 -m http.server

The sleep makes sure (well, very likely at least) the server is up-and-running before the open is executed. However, there's still the potential for failure if python3 -m http.server takes longer than a second – make certain to document this possibility.