Custom Shell

A powerful Unix-like shell implementation in C, developed as a course project for CS3.301 - Operating Systems and Networks.

Table of Contents

1. Introduction
2. Features
3. Getting Started
   • Prerequisites
   • Installation
   • Running the Shell
4. Usage
   • Custom Commands
   • System Commands
   • I/O Operations
   • Process Management
   • Networking
5. Advanced Features
6. Assumptions

Introduction

This custom shell project implements a feature-rich Unix-like shell in C. It supports various custom commands, system commands, background processes, logging, I/O redirection, piping, and more. The shell provides a user-friendly interface with a custom prompt and color-coded output for enhanced usability.

Features

• Custom Prompt: Displays username, system name, and current working directory
• Multiple Command Execution: Supports sequential and background execution
• Custom Commands: Includes hop, reveal, log, proclore, seek, activities, ping, fg, bg, neonate
• System Command Execution: Supports both foreground and background processes
• I/O Redirection and Piping: Enables complex command chaining and data manipulation
• Process Management: Provides tools for monitoring and controlling processes
• Command History: Logs and manages command history for easy recall and execution
• Networking Capabilities: Fetches man pages from the internet

Getting Started

Prerequisites

• GCC Compiler
• Make utility
• Unix-like operating system (Linux, macOS)

Installation

1. Clone the repository:

   git clone https://github.com/frindle18/Custom-Shell
   cd Custom-Shell
   

2. Compile the shell:

   make
   

Running the Shell

After compilation, start the shell with:

./shell

Usage

Custom Commands

1. hop: Change the current working directory

   hop <directory>
   

   • Supports ., .., ~, and - as special arguments

2. reveal: List files and directories with color-coded output

   reveal [options] [directory]
   

   • Options: -a (show all), -l (detailed view)

3. log: Manage command history

   log
   log purge
   log execute <index>
   

4. proclore: Display process information

   proclore [pid]
   

5. seek: Search for files or directories

   seek [options] [search_term] [target_directory]
   

   • Options: -d (directories only), -f (files only), -e (execute/change directory)

6. activities: List all processes spawned by the shell

   activities
   

7. ping: Send signals to processes

   ping <pid> <signal_number>
   

8. neonate: Print the PID of the most recently created process

   neonate -n <interval_seconds>
   

System Commands

Execute standard system commands in foreground or background:

command [args]    # Foreground
command [args] &  # Background

I/O Operations

1. I/O Redirection:

   command > output.txt   # Output redirection (overwrite)
   command >> output.txt  # Output redirection (append)
   command < input.txt    # Input redirection
   

2. Pipes:

   command1 | command2 | command3
   

Process Management

• Foreground Process Control:

  fg <pid>
  

• Background Process Control:

  bg <pid>
  

Networking

• iMan: Fetch man pages from the internet

  iMan <command_name>
  

Advanced Features

• Aliases: Define custom aliases in .myshrc configuration file
• Multiple Command Execution: Use ; for sequential execution and & for background execution
• Signal Handling: Support for Ctrl-C, Ctrl-D, and Ctrl-Z

Assumptions

• Paths and filenames should not contain whitespace characters
• The seek command's target directory should always start with .
• Commands from "log execute" are not added to the command history
• Aliases do not support multiple processes
• Functions can have commands with varying numbers of arguments and will still work correctly

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Developed as part of CS3.301 - Operating Systems and Networks course project.