I want to make something, kind of like the Windows commandline thing. Such as, the program will have a number of recognized commands such as 'log' or 'run'. This is for learning purposes, so I don't care if these commands exist already. How exactly do I check if the command is recognized or if the parameter after it, is valid. For example, I type 'run blah', this will not be valid. But how can this be checked? Also, how do I define the commands like 'run' or 'log'?