May 12 2017
Another tip to pass along to all those working on command line - DON'T COPY AND PASTE CODE. I don't know why, but this is particularly common in students learning R (from my experience)...
There are a couple reasons for this firm suggestion and post. The first is purely pedagogical - if you copy and paste large blocks of code without reading them, you lose out on understanding what the code is doing. Try to go through commands and figure out what the options mean (using man pages, google, etc.). Eventually this becomes more intuitive as time goes on, but you won't get there if you don't put in the exploratory time! Also, without knowing what the code is doing, you are adopting assumptions you don't even know are there. That's not great for science!
Another reason for this is security. It can be easy to inject invisible code into what you are copying, causing havock on your machine. If you MUST copy and paste code, at least put it in a text editor first!
Good luck and happy explorations!