Minishell

📖 Overview

Minishell is a simplified implementation of a Unix shell, developed as part of the 42 School curriculum.
It replicates core functionalities of bash while offering a controlled environment to explore process management, command parsing, file descriptors, and signal handling in C.

Our version achieved full score and supports robust command execution, including pipes, redirections, variable expansion, and built-in commands.

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✨ Features

• Command Parsing & Execution
  • Executes both built-in and external commands.
  • Handles multiple arguments, quoting, and special characters.
• Redirections
  • Input redirection: <
  • Output redirection: >
  • Append redirection: >>
• Pipes
  • Supports multiple chained commands using |.
• Environment Variable Expansion
  • $VAR expansion based on current environment.
• Built-in Commands
  • echo, cd, pwd, export, unset, env, exit
• Signal Handling
  • Ctrl + C — Interrupt current command without exiting the shell.
  • Ctrl + \ — Quit signal handling.
  • Ctrl + D — Exit shell gracefully.
• Error Management
  • Syntax checks for unclosed quotes, invalid redirections, etc.
  • Proper file descriptor cleanup to prevent leaks.

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📦 Dependencies

• Language: C
• Compiler: cc
• Flags: -Wall -Wextra -Werror -lreadline
• Libraries: GNU Readline for input handling.

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📂 Project Structure

ft_minishell/
│
├── minishell.c                # Entry point
├── execution/                  # Command execution logic
├── includes/                   # Header files
│   └── parsing/
├── libft/                      # Custom C standard library functions
│   └── ft_fprintf/
├── parsing/                    # Parsing and tokenizing
│   ├── ast/                    # Abstract Syntax Tree
│   ├── env/                    # Environment variable handling
│   ├── expansion/              # Variable and wildcard expansion
│   │   └── wildcards/
│   ├── pre_ast/
│   ├── syntx_check/            # Syntax validation
│   └── tokenize/               # Token generation
├── Makefile
└── README.md

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⚙️ Installation & Usage

1️⃣ Clone the repository

git clone https://github.com/LawKmu/shell-imzine.git
cd ft_minishell

2️⃣ Compile

make

3️⃣ Run

./minishell

You will see a custom prompt where you can type commands, e.g.:

ft_minishell$ echo "Hello World"
Hello World

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🧠 Key Concepts Learned

• Process Management
  • Using fork(), execve(), and wait() for command execution.
• Pipes & File Descriptors
  • Redirecting input/output between processes.
• Signals
  • Handling asynchronous events with signal() and sigaction().
• Parsing & Tokenization
  • Building a shell parser from scratch (tokens → AST → execution).
• Memory Management
  • Avoiding leaks and ensuring safe cleanup.
• Environment Handling
  • Modifying and expanding environment variables dynamically.

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🏆 Authors

• Mouad Ait El Aouad
• Zakaria Jaddad

This project is part of the 42 curriculum and adheres to its coding and formatting standards.