This is a very hand summary of daily useful tasks to be used on the command line

The Art of the Command Line

as the author notes, you can’t really call yourself a “true” developer, if you are not comfortable executing at least basic tasks in a shell.

in fact, I would argue, I would never consider anyone for a developer’s job who doesn’t do most of their development on a Linux box (that, obviously, includes Mac OS X) and is comfortable with bash scripting to automate most tasks.