ijtan/neo-eggshell-terminal

A native low-level Terminal written in C++

Welcome to Egg Shell!

Introduction

In this project I will be attempting to create a mini shell, from which I can execute external commands, execute internal commands, interact with environment Variables (create/retrieve).

Compilation

This project uses cmake which greatly faciliattes the compilation process. CMake version 3.16+
To Compile Simply run:

cmake CMakeLists.txt
make

Execution

C++ Version 20
To execute simply Run 'neoEggshell' from the build folder

./neoEggshell

Internal Commands

- echo
- unset <variable name>
- MYVAR=MYVALUE                     (for setting environment variables).
- showenv
- listproc                          (Show suspended processes)
- <command 1> | <command 2> | ...   (Piping)
- <command> * <filneame>            (Redirects where * = ['>'/'>>'/'<'])
- source <filename>                 (Read and parse commands line by line from text file)
- bg
- <command> &                       (Ampersnad after commands -> do not wait for them to finish)
- cd <dir>
- exit

External Commands

External commands can be run normally by entering them in the prompt.

Features

multiple commands can be entered in one line by using semicolons:

command1;command 2

White Space can be escaped by using Quotes

mkdir "Hello World"

If the entry does not contain an even number of quotes, the user is asked for more input:

mkdir "hel
llo"

Issues

When using the ampersand '&' feature, the output does not come as expcted, and comes all over the terminal (Probably an issue with the prompt and the outputs happening simulatenously). The same prpblem occurs when using the bg command, as two outputs happen simultaneously.

The bg and '&' features also leave behind zombie processes as they are never waited for.