Thanks for sharing. This is perfect timing for me as, having written a lot of Node.js CLIs over the years, I've been trying to learn Rust by rewriting one of them. This is helpful to check my progress against and tweak accordingly.
I find it helpul too. Basic filesystem I/O is an accessible topic for beginner programmers. It's the first time I've really consumed much Rust-related knowledge at all, and it was easy/palatable.