🐚 MyShell

A custom Unix shell built from scratch in C

About

A fully functional Unix shell implementation written in C as part of DCU's Operating Systems module (CA216). Supports internal commands, external program execution, I/O redirection, piping, and background processes.

Features

• Built-in commands: cd, clr, dir, environ, echo, pause, help, quit
• I/O redirection: Input (<) and output (>, >>) redirection
• Background execution: Run processes in the background with &
• Environment variables: Full environment variable support
• Manual pages: Built-in help documentation

Project Structure

├── src/
│   ├── myshell.c      # Main shell loop & command parsing
│   ├── myshell.h      # Header file & function declarations
│   ├── utility.c      # Utility functions & built-in commands
│   ├── utility.h      # Utility header
│   ├── makefile       # Build automation
│   └── help.txt       # Built-in manual page
└── manual/            # Documentation

Build & Run

cd src
make           # Compile
./myshell      # Run the shell

Usage

myshell> echo Hello World
Hello World

myshell> dir /home
...

myshell> ls -la > output.txt    # Output redirection

myshell> sleep 10 &             # Background execution

myshell> help                   # View manual

Tech Stack

• Language: C
• Build: Make
• Platform: Unix/Linux

Author

Kevin — Dublin City University

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DCU CA216 — Operating Systems