I'm doing integration tests (as I stated in the second sentence) and so I don't want to have to re-write any of the existing machinery. I only want to check to make sure that it does what it's supposed to do. Otherwise there are a number of less painful ways to do this.
I'm not sure why piping the startup command for the first program to a file hadn't occurred to me. Although... as it turns out it looks like that doesn't capture all of it's output... strange.