When you type commands in the terminal, that’s **standard input**. When you run the command, the results typically go to **standard output**. This input/output model allows you to chain commands ...

GUIs are great—we wouldn’t want to live without them. But if you’re a Mac or Linux user and you want to get the most out of your operating system (and your keystrokes), you owe it to yourself to get ...

We’ve got commands like pwd, but … pwd tells you where you are on the file system, not where the script you are calling is located. OK, let’s try again. We have echo $0. But, no, that’s not much ...