Minishell

A simple shell implementation based on bash.

Overview

Minishell is a custom implementation of a basic command line interpreter, similar to bash. This project is part of the 42 School curriculum and focuses on process creation, file descriptors, and signal handling in a Unix environment.

Features

Command Execution

• Execute external commands with arguments (e.g., ls -la, grep pattern file)
• Handle executable paths and environment PATH variable

Built-in Commands

• echo: Display messages with -n option support
• cd: Change current directory
• pwd: Display current working directory
• export: Set environment variables
• unset: Remove environment variables
• env: Display environment variables
• exit: Exit the shell with status code

Input/Output Handling

• Input redirection (<)
• Output redirection (>)
• Append output (>>)
• Here documents (<<)
• Pipes (|) to connect commands

Environment

• Environment variable expansion (e.g., $USER, $PATH)
• Exit status variable ($?)

Signal Handling

• Ctrl+C (SIGINT): Interrupt current process
• Ctrl+D (EOF): Exit shell
• Ctrl+\ (SIGQUIT): Ignored in interactive mode

Installation

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

Usage

./minishell

Examples

Basic command execution:

> ls -la

Redirections:

> echo "Hello" > file.txt
> cat < file.txt

Pipes:

> ls -la | grep .c

Environment variables:

> echo $USER
> export VAR=value
> echo $VAR

Technical Implementation

• Lexer/Parser: Tokenizes and analyzes user input
• Command Execution: Creates child processes using fork and execve
• Redirections: Manages file descriptors for I/O operations
• Environment Management: Handles environment variables in a linked list
• Signal Handling: Custom signal handlers for terminal signals

Dependencies

• GNU Readline library

Author Username

@ma1loc for @me i did the execution part

@bronIIcode

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This project was completed as part of the 42 School curriculum.