UNIX Command Interpreter

A simple UNIX command interpreter built from scratch.

Overview

This project is a simple UNIX command interpreter, developed to understand systems programming and the workings of a command-line interface (CLI). It was built in collaboration with Basem1166.

Features

• Basic UNIX command execution such as ls, cd, pwd, echo, etc.
• Supports input/output redirection and piping.
• Custom-built command parser and executor.
• Error handling for command execution and input.

Project Structure

• shell.c: Contains the main loop for the shell interpreter.
• shell.h: Header file with definitions and function prototypes used across the program.
• execution.c: Handles the execution of commands.
• shellutil.c: Utility functions for managing shell operations.
• utilities1.c, utilities2.c: Additional utility functions to support command processing.
• hsh: Executable file for the interpreter.
• TEST_SUITE/: Directory containing test cases to validate different functionalities.
• .gitignore: Specifies files and directories to be ignored by Git.
• AUTHORS: Contains the names and contact details of the authors.
• README.md: Documentation file (this file).

Getting Started

Prerequisites

To run this interpreter, you will need:

• A UNIX-like operating system (Linux, macOS, etc.)
• A C compiler (such as gcc)

Installation

1. Clone the repository:

   git clone https://github.com/tahaaa22/simple_shell.git
   cd simple_shell

2. Compile the source code:

   gcc -o hsh shell.c execution.c shellutil.c utilities1.c utilities2.c

3. Run the interpreter:

   ./hsh

Usage

Once you run the interpreter, you can execute UNIX commands directly from the CLI. For example:

$ ls -l
$ cd /home/user
$ echo "Hello, World!"
$ cat file.txt | grep "search_term"

Design

The interpreter consists of several modules:

• shell.c: Implements the main loop that reads user input and triggers command processing.
• execution.c: Contains the logic to execute commands, handle processes, and manage I/O redirection.
• shellutil.c, utilities1.c, utilities2.c: Provide various utility functions for parsing commands, handling errors, and other operations.

Testing

To test the interpreter, run the test scripts available in the TEST_SUITE/ directory:

cd TEST_SUITE
./run_tests.sh

Authors

• Ahmed Taha
• Basem el-galfy

Acknowledgments

Thanks to the open-source community for the resources and inspiration.

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