I use clap/structop in Rust for all my CLIs ever since those libraries came out and it's just stupid easy to make a nicely functioning CLI. You define a data st

I use clap/structop in Rust for all my CLIs ever since those libraries came out and it's just stupid easy to make a nicely functioning CLI. You define a data structure which holds the arguments a user will pass to your program and you can annotate fields to give them short and long names. You can also define custom parsing logic via plain functions if the user is passing something exotic. At the end you can parse arguments into your data structure in one line. At that point the input has been validated and you now have a type safe representation of it. Well-formatted help text comes for free.