Productivity hacks utilizing the shell are one of my favorite things in this world, right up there with music, video games, and Diet Pepsi. There's nothing like the feeling you get when you discover a useful feature that saves you time or increases your efficiency. There are many things I've discovered along the way that I wish I had known earlier on. One of my goals while writing this book is to teach you as many things as I can that took me longer to learn than it should have. In this section, in no particular order, I'll go over a few tricks that increased my work-flow.
First, entering !! (two exclamation marks) in your Terminal will repeat the command you last used. By itself, this may not seem like much. After all, you can press the up arrow key once and press Enter to recall the previous command and execute it. But...
