minishell

A small shell implementation in C, recreating key features of Bash 3.2.

📖 Description

The minishell project recreates a simplified version of Bash.
It allows executing commands, handling redirections and pipes, managing environment variables, and implementing built-in commands.
This project strengthens understanding of:

• "Parsing and Abstract Syntax Trees (AST)"
• "Process creation (fork, execve)"
• "Signals (ctrl-C, ctrl-D, ctrl-\)"
• "Redirections, heredocs, and pipes"

🛠️ Features

✅ Mandatory

• Display a prompt and wait for commands
• History functionality
• Locate and launch executables (builtins, $PATH, relative/absolute paths)
• Manage single/double quotes
• Implement redirections (<, >, <<, >>)
• Implement pipes (|)
• Manage environment variables ($) and $?
• Proper signal handling (ctrl-C, ctrl-D, ctrl-\)

🔥 Bonus

• Logical operators: && and ||
• Parentheses for priorities (no subshells)
• Wildcard * (current directory only)

Builtins Implemented

• echo with -n
• cd (relative/absolute paths)
• pwd
• export
• unset
• env
• exit

❌ Limitations

"No unclosed quotation marks" "No unsupported characters (e.g., \ backslash, ; semicolon)" "No features outside the subject specification"

🧩 Global Structure (Abstract Syntax Tree)

📦 Installation

Clone the repository and compile:

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

🚀 Usage

Run the shell:

./minishell

To debug tokenization and AST generation:

./minishell debug

Example

minishell$ echo 1 | cat -e || (echo 2 && echo 3) || echo 4

👤 Authors

• hanmpark
• Kariyu42