rscres / 42minishell

A small and simple implementaion of a shell to better understand its workings.

minishell

Intro

This project aims to create a simple shell, based on bash, in C. At this point of the cursus it's by far the largest project we have worked on and also it's the first one we must work in pairs.

Usage

1. Download/Clone this repo

    git clone https://github.com/rscres/42minishell
   

2. cd into the project directory and run make

    cd 42minishell
    make
   

3. Run the minishell

   ./minishell
   

About the minishell

The project had to be coded in C and we were limited on the lib functions we could use.

Some of the shell commands were implemented as builtins:

• echo
• exit
• export
• env
• unset
• cd
• pwd

Echo was implemented with the -n flag and the rest without any flags. The minishell is capable of running other commands, like ls or wc, but will do it using execve().

42minishell's Issues

Unclosed quotes cmd line causing double free()

When passing a command with unclosed quotes (lexer.c: lines 121-135), it causes double free. Need to check why

shell quiting when running pipe commands

cd crashing when passed without args

invalid read size if try to execute cd command without passing any args

Command arg list not being created correctly

In some cases, like no args and with redir, args list is not properly being set and apparently not being NULL terminated, causing segfault when command is called like that.

Quote handling not working properly

When passing commands like: echo "'"'"'$USER'"'"'"
The quote handler is not removing the correct quotes.