I'm doing some foundational review to make sure I'm on solid footing when I'm working on Rails – currently going through Software Carpentry's Unix shell for novices sequence – and there is this wee thing I think I never knew.
In a Unix shell,
cd -
will take you back to the previous directory.
How I could not know this after half my life in IT? I'm going to posit that it doesn't exist in DOS, and I just plain missed it when I made the transition because I could get wherever I needed to be easily.
As you were.