ShellX

A very simple Unix shell implementation with job control, command history persistence, and pipeline support.

Features

Core Functionality

• Command execution with arguments
• Pipeline support for command chaining
• Job control (background/foreground processes)
• Command history with SQLite persistence
• Directory navigation
• Signal handling (SIGINT, SIGTSTP, SIGCHLD)

Built-in Commands

• cd [path]: Change directory (supports ~ for home directory)
• bg [job_id]: Resume stopped job in background
• fg [job_id]: Bring background/stopped job to foreground
• jobs: List all background and stopped jobs
• exit: Exit the shell

Prerequisites

• GCC compiler
• Make build system
• SQLite3 development libraries
• GNU Readline development libraries

Installation

1. Install dependencies (Ubuntu/Debian):

sudo apt-get install gcc make libsqlite3-dev libreadline-dev

2. Clone the repository:

git clone https://github.com/yourusername/shellx.git
cd shellx

3. Build the project:

make

4. Run the shell:

./shell

Project Structure

shellx/
├── Makefile
├── include/
│   ├── shell.h          # Core definitions and structures
│   ├── job_control.h    # Job control functionality
│   ├── command.h        # Command parsing and execution
│   ├── history.h        # Command history management
│   ├── builtins.h       # Built-in command handlers
│   └── signals.h        # Signal handling
├── src/
│   ├── main.c          # Shell entry point
│   ├── job_control.c   # Job management implementation
│   ├── command.c       # Command processing
│   ├── history.c       # History database operations
│   ├── builtins.c      # Built-in command implementation
│   └── signals.c       # Signal handlers
└── build/              # Compiled objects (created by Makefile)

Usage Examples

1. Basic command execution:

[/home/user]🐚 ls -l

2. Pipeline commands:

[/home/user]🐚 cat file.txt | grep pattern | wc -l

3. Job control:

[/home/user]🐚 sleep 100
^Z
[/home/user]🐚 bg
[/home/user]🐚 fg