Minishell

A simple shell interpreter that replicates basic Bash functionalities. This project is part of the 42 School curriculum.

Overview

Minishell implements a basic command-line interpreter with:

• Command execution
• Pipes (|)
• Redirections (<, >, >>)
• Environment variables ($)
• Here-Documents (<<)
• Signal handling (ctrl-C, ctrl-D, ctrl-\)
• Built-in shell commands

Built-in Commands

• echo (with -n option)
• cd
• pwd
• export
• unset
• env
• exit

Installation

git clone git@github.com:42OK42/Minishell.git
cd Minishell
make

Usage

./minishell

Examples

# Simple commands
> ls -la

# Pipes
> ls | grep .c

# Redirections
> ls > output.txt
> cat < input.txt

# Environment variables
> echo $PATH

# Here-Document
> cat << EOF
> This is the text
> Multiple lines possible
> EOF

Key Learnings

• Process Management: Deep understanding of fork, exec, and pipes
• Signal Handling: Implementation of signal handlers for various terminal events
• Parsing: Development of a robust parser for shell syntax
• Memory Management: Careful memory management to avoid leaks
• Error Handling: Comprehensive error handling for various edge cases

Technical Details

• Written in C
• Uses readline library for input handling
• Implements custom parsing logic
• Handles complex command chaining

Project Structure

.
├── src/
│   ├── execution/       # Command execution
│   ├── parsing/         # Input parsing
│   ├── built_ins/       # Built-in commands
│   └── utils/          # Helper functions
├── incl/               # Header files
└── libft/              # Custom C library

Known Limitations

• No support for complex Bash features like wildcards or functions
• Limited error handling compared to original Bash
• No job control

Contributors

• bschmidt

License

This project is part of the 42 School curriculum.