There is a total of three strings I need from the user, I think this is easier done interactively than having them set three different environments variables. Also, I'd like to give them some information about the nature of the test they will be running. You're right, this can be put into the README or INSTALL files, but nobody reads the damn things ;-).
somebody who wants to run the interactive tests should know how to do it for the respective OS ;)
True, and moritz makes an excellent point about it not even being the same on csh. I'll probably just tell them to set the environment variable and provide further assistance in the README file which they can read if they need it. Thanks!