How can a shell script control another script

Question

I remember vaguely a technique using pipes for communication between two shell processes.

Are there any tutorials available on how to setup and control a subshell?

Answer 1

Are you talking about named pipes?

mkfifo pipe
ls -l >pipe #type this is one shell
cat <pipe #type this is another one

No one reads if no one writes.
No one writes if no one reads.