Hi!
@fibric makes a good suggestion. commander is a good choice for parsing command line arguments. One of the strengths of Node is the ecosystem, so if you do not like commander for the argument-parsing part of your command line client there are many other mature and battle-proven modules: e.g. optimist, nopt and yargs.
I was maintaining npm a few years ago and based on my experiences maintaining a command line tool which runs on node, has traction and is doing everything to make the user successful I wrote a book: http://theclibook.com/
You don't have to buy the book, there is still a big part which is downloadable for free as preview. I hope that helps. If you have any questions, ping me: https://twitter.com/robinson_k