Checkout **xtrv** a file archive utility I created while learning C.

URL: https://github.com/ttshivhula/xtrv

If you like it you can give it a star. contributions are welcomed!

You could try adding compression via zlib, it's quite straightforward
https://zlib.net/zlib_how.html

@RememberMe thanks I'm definitely going to try that. If you have time you can also create a PR

Your "protection" is terrible. Use proper encryption instead of a self made xor variant.

NaCl has a 'failsafe' secret key algorithm, but you'd need to derive a good key from the password (e.g. with 50k rounds of pbkdf2 or argon2).

Your program flow in the main method is unnecessarily hard to follow.