One of the very famous 42 curriculum projects. Code name was "miniHELL" The goal of the subject was to recreate some of the functionalities of bash (Version 3.2).
The guideline was "check bash" So it gave us an infinite possibility for bug hunting. Edge cases after edge cases. Our project canvas was looking like a Christmas tree. But we made it through. After some segf! we had it running. Our own personal and beautiful command line tool!

The existence of shells is linked to the very existence of IT. At the time, all coders agreed
that communicating with a computer using aligned 1/0 switches was seriously
irritating. It was only logical that they came up with the idea to communicate with
a computer using interactive lines of commands in a language somewhat close
to english.
With Minishell, you’ll be able to travel through time and come back to problems
people faced when Windows didn’t exist.

• this is a shell that can be compiled by running
  make
  and then to run it
  ./minishell
  
• now you are greeted with a prompt HAKUNA_MATATA$  waiting for input just like any other shell ...