Simple Shell Project

This project implements a simple UNIX command interpreter shell in C programming language, capable of running commands in both interactive and non-interactive modes. It provides a basic understanding of how shells work and serves as a starting point for further exploration and customization.

Main Features

• Runs in both interactive (REPL) and non-interactive modes
• Implements built-in exit and env commands
• Splits input into tokens using a delimiter
• Forks processes to execute commands from $PATH
• Searches across list of paths to locate commands
• Outputs error if command not found
• Counts number of commands executed

Function Definitions

Main Shell Functions

shell

• Decides whether to run in interactive or non-interactive mode

shell_interactive

• Implements REPL loop prompting for user input

shell_noninteractive

• Reads input from stdin and executes

Execute Command Functions

handle_execution

• Parses input and executes commands

execute_fork

• Spawns process and runs command using execve

Future Enhancements

Input/Output

• Implement output redirection (> and >>)
• Implement input redirection (< and <<)
• Implement pipes (|) to connect commands

Additional Builtins

• Add more built-in commands like echo, help etc.

User Customization

• Set up initialization script to run on shell start
• Add command history and search
• Support tab autocompletion

Error Handling

• Improve control-C signal handling
• Enhance error messages and logging

Batch/Scripting

• Support running script files with multiple commands
• Handle line continuation with backslash
• Add conditional logic and loops

Getting Started

Prerequisites

Ensure you have the following installed:

• C Compiler (e.g., GCC)
• Standard C Library Headers

Installation

Clone the repository and compile the source code:

git clone https://github.com/mohamedtharwat000/simple_shell.git
cd simple_shell
gcc -o your_shell_name *.c

Usage

Interactive Mode

Run the shell:

./your_shell
Enter commands interactively.

Non-Interactive Mode

Run the shell with a script:

./your_shell < script.txt
Provide a script with commands to execute non-interactively.

Contributing

Contributions are welcome! Here are some ways you can contribute to this project:

• Report bugs and issues
• Fix bugs and issues
• Add new validation functionality
• Improve styling and overall UX
• Refactor code to improve quality
• Write documentation and improve existing docs

To contribute:

1. Fork the repository
2. Create a new branch
3. Make your changes and commit them
4. Push your branch and submit a pull request

I will review pull requests and provide feedback.

License

This project is open source and available under the MIT License.

Credits

Created by Mohammed Khalid and Mostafa Mokhtar