Shell Framework

What is this?

A framework to create your own shell in Java. You can add your custom shell commands into the shell application easily.

Features

Definition flexibility: Define your own commands easily by extending Abstract command class.
Simple configuration: 1 line to add a new command to the existing shell.
Clear, simple structure: Designed to add new commands to the shell without having to worry about the phases of execution
Maintain history: Get the history of commands executed previously.

Installation/Integration

1. Download/clone the repo into an appropriate folder
2. Add custom commands in the src directory.
3. Add command/s to the application.
4. Run the application's interpreter.
5. Reward yourself with a refreshing beverage.

Sample command integration

Adding a custom command is as easy as pie. It goes like this:

If you want a command called 'curl', you create the Curl class in this way.
It has to extend the class AbstractCommand.
It has to have a constructor with 2 params:
```
  String baseCommand
  int params
```
The constructor has to invoke the superclass' constructor:
```
  super(baseCommand, params)
```
It has to override 3 methods:
```
  execute
  getDescription
  getUsage
```

Lets add a custom command called Curl (which is a command-line http request tool in Linux). So, the class Curl looks like this:

  public class Curl extends AbstractCommand {
  	public Curl(String baseCommand, int params) {
  		super(baseCommand, params);
  	}
  	
  	@Override
  	public void execute() {
  		System.out.println("running curl command...");
  	}

  	@Override
  	public String getUsage() {
  		return "curl [method] [host]";
  	}

  	@Override
  	public String getDescription() {
  		return "make http requests from command-line";
  	}
  }

Now that you have a command class Curl, lets add this to the shell application.

  public class AppMain {
  	public static void main(String[] args) throws Exception {
  		Application app = new Application();
  		app.addCommand(new Curl("curl", 1)); // Add the command to app. Curl is the base command and numner of params it takes is 1
  		app.setStartupInfo("Custom shell v0.01");
  		app.setPrompt("shell>"); // set your prompt text
  		app.interpret();
  	}
  }

And you're done!
Just run the main class and voila! You have your shell with your custom commands.

Enhancements

The shell app is not thread-safe. I shall start working on it soon.
It doesn't allow you to pass variable number of params. While running a command, it has to have the number of params you had defined while creating the command

mrwonderman / shell-framework