How to implement a stdin, stdout wrapper?

Question

I have an interactive program that runs stdin and stdout. I need to create wrapper that will send X to it\'s stdin, check that it prints Y and then redirects wrapper\'s stdin an

Answer 1

Assuming X and Y are files, and that you can invoke the program more than once:

#!/bin/bash

test "`program 

Or, to fail more verbosely:

#!/bin/bash

if [[ `program 

If you only invoke the program once, Expect is a much simpler alternative than reassigning standard file I/O on the fly.