Design pattern for command line software with multiple functionalities

I'm developing a program that is going to be called from the command line. The software will be a sort of 'kit' with differing functionality based on the different flags defined while calling the program. Some of this functionality is wildly differing from others and the only similarity is the type of file that it operates on.

I was wondering what the best design pattern is to implement this kind of functionality? I've read about the facade design pattern which splits each module into a different sub-system. Building each piece of functionality under a different facade would keep it modular and would allow me to build a single class to handle which facade to call.

Is this the best way to go about it, or would you recommend something different?

Thanks, Sam