[poopicus]

This is a brilliant idea, and may I suggest that one takes it slightly further than just implementing the core functionality, and aiming for a complete clone (optional parameters and all) with a few enhancements.

Indeed, for a further ego boost, why not also benchmark the performance of your versions against the performance of the native utilities? You never know, your new clone might end up being the new 'less' to the old 'more'!

[rodrigoavie]

Yes. I think I nice approach would be just cloning core functionality of the program initially in your language of choice, then dealing with parameters and more advanced options as you learn that language better.