Minishell 🐚

Miguel Diogo

Angela Lima

Minishell is a shell program written in C that provides a simplified command-line interface for executing commands and managing processes. It aims to replicate basic functionalities of a Unix shell, such as command execution, I/O redirection, piping, and handling of environment variables. The subject of the project can be found in this link.

📜 Instructions

• Language: C
• Norm: The project must adhere to the Norm, a set of rules and coding conventions.
• Dependencies: The project can use external libraries such as readline for line editing capabilities.
• Memory Management: Proper memory allocation and deallocation should be ensured to prevent memory leaks.
• Makefile: A Makefile should be included, providing rules to compile the project with required flags and dependencies.
• Separate Compilation: The Makefile should not relink, and the project should be organized into multiple files if necessary.
• Bonus: Additional features or functions can be implemented as bonuses, but they will be evaluated separately.

⚙️ Features

• Prompt: Minishell displays a prompt to indicate it is ready to accept commands.
• History: The shell maintains a history of previously executed commands.
• Command Execution: Minishell searches for and launches the appropriate executable based on the PATH variable or using a relative/absolute path.
• Quoting: Minishell handles single quotes (') and double quotes (") to prevent interpretation of metacharacters within the quoted sequence.
• Redirection: The shell supports input (<) and output (>) redirection, as well as appending output (>>) to a file. It also supports here documents (<<) with a delimiter.
• Pipes: Minishell implements pipes (|) for connecting the output of one command to the input of another.
• Environment Variables: The shell expands environment variables (e.g., $VAR) to their corresponding values.
• Special Variables: Minishell expands $? to the exit status of the most recently executed foreground pipeline.
• Signal Handling: The shell handles signals such as ctrl-C, ctrl-D, and ctrl-\ as expected.
• Built-in Commands: Minishell provides several built-in commands:
  • echo -n: Prints arguments to the standard output without a trailing newline.
  • cd: Changes the current working directory to the specified path.
  • pwd: Prints the current working directory.
  • export: Sets or exports environment variables.
  • unset: Unsets environment variables.
  • env: Prints the environment variables.
  • exit: Exits the shell.

📂 Project Structure

The Minishell repository consists of the following files:

• Makefile: Makefile for compiling the project.
• *.h: Header files containing function prototypes and necessary definitions.
• *.c: Source code files containing the implementation of various features and built-in commands.

🚀 Usage

To compile the Minishell project, run the following command:

make

This will generate an executable named minishell.

To launch the shell, run the following command:

./minishell

Once the shell is running, you can enter commands and utilize the supported features.