Perl for Web Site Management

Meet the Unix Shell

The Unix shell is the program that interprets the things you type at the command-line prompt. It is called the shell because it forms a shell around the computer’s lower-level functions so that you, the user, don’t have to deal with them directly.

If you’ve been using personal computers long enough to remember poking around in the DOS command-line environment, guess what? That experience is going to prove useful. In many ways working in DOS is similar to working in a Unix shell session (though Unix fans will say it’s similar in the same sense that driving a soapbox racer is similar to driving a Ferrari).

If your computing experience has been limited to using a graphical environment like Windows or the Mac OS, this is going to seem a bit strange at first. If you stick with it, though, you’ll come to appreciate the power and flexibility of the command-line interface.

It’s a bit like LEGO blocks. The command-line interface is like the LEGOs I grew up with 30 years ago: you got the little square one and the slightly bigger rectangle and the really big rectangle and so on. The individual components were basic, but if you put them together with sufficient imagination you could make a spaceship, or a fire engine, or a skyscraper, or whatever you wanted. Unix commands are designed to be put together with each other in the same way, and before you know it you’ve got a custom tool to solve whatever your particular problem is.

A graphical interface is more like those fancy ...