That TUI program reminds me: back in the day, on Xenix systems, there was a program (it may have been an optional install) called 'learn'. Learn gave you basic

That TUI program reminds me: back in the day, on Xenix systems, there was a program (it may have been an optional install) called 'learn'. Learn gave you basic lessons in how to manage files with the Unix command line utilities: moving, copying, deleting, editing, etc. At the end of each lesson it would test you by dropping you into a fake shell with a fake file system and having you perform the appropriate commands. It would respond the way a real shell would, and if you screwed up the worst thing that would happen was having to repeat the lesson. I think that when it comes to complicated things like shells and programming languages, allowing the learner to play with the concepts involved is super important. So, thanks for reflecting that in the program.