🐚 Minishell

A feature-complete POSIX shell implemented in C

---

📝 Overview

A fully functional shell built in C for the 42 curriculum, replicating key behaviors of bash.
Supports job control, command parsing, environment management, expansions, and built-in commands.
All logic written from scratch with a custom lexer, parser, and executor architecture.

---

DISCLAIMER

This is a Show Repository. The original we worked on is here.

---

✨ Features

• 🧠 Custom Lexer & Parser
  Built from scratch to tokenize, parse, and construct abstract syntax trees.

• ⚙️ Execution Engine
  Executes commands with pipelines, logical ops (&&, ||), redirections, and subshells.

• 🧩 Built-in Commands
  Fully re-implemented: cd, echo, pwd, export, unset, env, exit.

• 🔄 Environment Variable Handling
  Robust getenv, setenv, and unsetenv functionality.

• 🔍 Word & Parameter Expansion
  Handles variables ($VAR), wildcards (*) and quotes.

• 🗃️ Redirection & Pipes
  Supports <, >, >>, heredocs (<<), and multi-command pipelines.

• 📡 Signal Handling
  Handling of SIGINT, SIGQUIT.

• 🧪 Robust Error Handling
  Error messages, status codes, and edge case coverage.

• 🧠 Bonus Features
  Includes subshells, command chaining, multi-line prompts, and more.

---

🚀 How to Run

git clone https://github.com/yourusername/minishell.git
cd minishell
make
./minishell

---

⚙ Command Syntax Overview

🛠 Click to expand

echo "Hello, $USER"
ls -al | grep minishell
cat << EOF
This is a heredoc
EOF

export PATH=$PATH:./bin
(cd srcs && ls)

Built-Ins	Explanation
cd	Change the current directory
export	Set an environment variable
echo	Print text to the terminal
exit	Exit the shell
pwd	Print working Dir
unset	Unset Env Variable
env	Prints Enviorment

---

📁 Project Structure

minishell/
├── include/              → Header files
│   ├── minishell.h       → Main includes
│   ├── lexer.h           → Lexer logic
│   ├── parser.h          → Parser logic
│   ├── ms_executer.h     → Command execution
│   ├── ms_env.h          → Environment handling
│   ├── ms_build_ins.h    → Built-in commands
│   ├── ms_expander.h     → Variable and wildcard expansion
│   └── ms_signal.h       → Signal handling
├── libft-42/             → Custom standard library functions
│   └── libft.h, *.c
├── srcs/
│   ├── lexer/            → Tokenization logic
│   ├── parser/           → Command tree builder
│   ├── executer/         → Execution engine
│   ├── env/              → Environment logic
│   ├── build_ins/        → Built-in implementations
│   ├── expander/         → Variable/wildcard expansion
│   ├── signal/           → Signal handlers
│   ├── readline/         → Prompt handling
│   ├── error/            → Error messages
│   └── main.c            
├── Makefile              
└── README.md             

👨‍💻 Authors

• @42mgr
• @bartsch-tech