This project has been created as part of the 42 curriculum by jsilveir, vsoares-.

minishell

Description

Minishell is a simplified shell implementation that replicates core functionalities of bash. The goal of this project is to understand how a shell works by building one from scratch, including process creation, file descriptor manipulation, signal handling, and command parsing.

Features

• Interactive prompt with command history
• Command execution via PATH lookup or absolute/relative paths
• Built-in commands: echo, cd, pwd, export, unset, env, exit
• Redirections: <, >, << (heredoc), >>
• Pipes: connect multiple commands with |
• Environment variable expansion: $VAR and $? for exit status
• Quote handling: single quotes '...' and double quotes "..."
• Signal handling: Ctrl+C, Ctrl+D, Ctrl+\

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Instructions

Prerequisites

• GCC compiler or compatible C compiler
• GNU Make
• readline library (libreadline-dev on Debian/Ubuntu)

Compilation

make

This will compile the project and generate the minishell executable.

Other Make targets

make clean    # Remove object files
make fclean   # Remove object files and executable
make re       # Rebuild the project

Execution

./minishell

Once running, you can use it like a regular shell:

minishell$ echo "Hello, World!"
Hello, World!
minishell$ ls -la | grep minishell
minishell$ cat < input.txt > output.txt
minishell$ export MY_VAR=42
minishell$ echo $MY_VAR
42
minishell$ exit

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Resources

Documentation & References

• Bash Reference Manual - Official GNU Bash documentation
• The Open Group Base Specifications - Shell Command Language - POSIX shell specification
• Writing Your Own Shell - Tutorial on shell implementation
• Readline Library Documentation - GNU Readline manual

AI Usage

AI assistance was used for:

• Learning and understanding key concepts: Explaining how certain concepts of the shell syntaxt and behavior work
• Code review and bug identification: Analyzing existing code to find potential issues, memory leaks, and norm violations
• Documentation: Generating and formatting README documentation and project checklists
• Refactoring suggestions: Identifying duplicate code and proposing structural improvements

All core implementation (parsing, execution, builtins, redirections, pipes, signals) was written manually by the project authors.