My attempt at writing a simple shell application

[naens]

Hello.

This is my attempt at making the project 9.  I decided to write a shell. It can evaluate variables and expressions.

Could you please give me your opinion on the design and the working of the application?

I am a newbie programmer and I would like to learn how I can improve.

Here is the code repository of the shell (it's called MUSH): <github link>.

And this is a youtube video of how it works and what it looks like: <youtube link>.

Thanks.