Interactive shell in background inside another shell script

Question

I have some problems when trying to run an interactive sh session inside a shell script. The inner sh process uses all the CPU and never terminates.

To reproduce the issue simply create a file named "script.sh" containing something like this:

sleep 10 | sh -i | sleep 10 &

and execute it using:

sh script.sh

sleep commands are just placeholders, I have other commands piping input into sh -i and processing its output. I know this is a very odd setup but it would be better if I could use an interactive shell and, at this point, I'm very curious and I want to understand what's happening.

Answer 1

You inner shell is not interactive; remove the -i flag and it should stop freaking out.

See What should interactive shells do in orphaned process groups? for an explanation of what is going on under the cover.