Mac OS X Power Hound, Second Edition

Terminal Help

An enormous number of programs have been written for Unix, with literally hundreds of them using Mac OS X. Funny thing is, you never see their icons, because they don’t have icons; they’re Unix programs, invisible until you type their names into Terminal and press Enter.

Each Unix command generally calls up a single one of these programs (or processes, as geeks would say) that opens, performs a task, and closes.

The most important way to learn about them is to try them out—although the following tips can help a little bit, too.

The Built-In Unix Manual

If you’re new to Unix, the most powerful command you can put to immediate use is man. Man, which stands for manual, displays the Unix system manuals (that is, help files). For example, you can type man uptime to find out what the uptime command does. That’s the good news.

The not-so-good news is that the manual pages for some commands are missing, incomplete, or confusing. Still, in most cases, the manual provides you with at least the basic information required to use a command.

The first manual you should read is probably the one for the man command itself, which explains the various command-line options available and, moreover, provides a couple of simple examples:

man man

One of the first things you’ll notice is that the manual stops at the end of the first screen with a : character. You can scroll a page at a time with the Space bar (or see the next hint for other scrolling options).

Tip

If you ever need to refer to the ...