Shellify

Shellify is a simple, lightweight shell implementation written in C. It provides core shell functionality with a clean, straightforward interface.

✨ Features

Shellify currently supports:

• Basic command execution
• Command-line argument parsing with support for spaces and special characters
• Built-in commands:
  • cd - Change directory (with support for empty argument to navigate to HOME)
  • pwd - Print working directory
  • path - Set search paths for executable discovery
  • exit - Exit the shell
• I/O redirection with > operator
• Command piping with | operator (multiple pipes supported)
• Path search for executable programs
• Signal handling
• Quoted argument handling (both single and double quotes)
• Process group management for proper job control

📥 Installation

To build and install Shellify:

git clone https://github.com/AhmedSobhy01/shellify.git
cd shellify
make

🚀 Usage

After building, run the shell:

./shellify

💻 Basic Commands

shellify> ls -l                # Run a command with arguments
shellify> cd /path/to/dir      # Change directory
shellify> cd                   # Change to HOME directory
shellify> pwd                  # Show current directory
shellify> ls -la > output.txt  # Redirect output to a file
shellify> exit                 # Exit the shell

🔄 Command Piping

shellify> ls -l | grep ".txt"                     # Pipe ls output to grep
shellify> cat file.txt | sort | uniq              # Chain multiple pipes
shellify> ps aux | grep bash | wc -l              # Count bash processes
shellify> find . -type f | grep "\.c$" > src.txt  # Combine pipes with redirection

🛣️ Path Management

Set directories where Shellify should look for executables:

shellify> path /bin /usr/bin /usr/local/bin

Using no arguments clears the path:

shellify> path

💬 Quoted Arguments

Shellify supports quoted arguments for handling spaces and special characters:

shellify> echo "Hello World"                  # Double quotes
shellify> touch "my file.txt"                 # Spaces in filenames
shellify> echo 'Single quoted string'         # Single quotes
shellify> grep "search term" "file with spaces.txt"

Quotes also support multi-token arguments:

shellify> echo "This is all one argument despite the spaces"

🔧 Implementation Details

Shellify is structured into several modules:

• shellify.c/h: Main shell logic, command processing, signal handling, and pipeline execution
• commands.c/h: Built-in command implementations and path resolution
• utils.c/h: Utility functions for argument parsing and command handling

Architecture

The shell follows a modular design:

1. Input Processing: Command-line input is read and parsed into arguments
2. Command Execution:
   • Built-in commands are handled internally
   • External commands are executed by searching the PATH
   • Pipelines create multiple processes with connected I/O
3. Signal Handling: Custom handlers manage interrupts and terminal control
4. Process Management: Process groups are used for job control

Signal Handling

Shellify implements proper signal handling to manage:

• Ctrl+C (SIGINT) for interrupting running commands
• Terminal control signals for managing foreground/background processes
• Process groups to ensure signals are delivered properly

🔮 Future Plans

• Command history navigation with the arrow keys
• Support for environment variables
• Input/output redirection for standard error

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.