Learning Unix for Mac OS X, Second Edition

Format

The following sections describe conventions used in this handbook.

Graphical User Interface Features

While this book spends most of its time on the Unix command line, we do sometimes need to tell you how to run programs from the GUI. We may do this with a compact syntax such as:

Finder → Applications → Utilities → Terminal

This shorthand should be read as: open the Finder, then choose Applications, then Utilities, then Terminal. We use the same syntax whether the user interface feature to be selected is a window, a menu item, or an icon. The meaning should be obvious from the context. If you don’t see a window or icon with the name we give, look at the menu bar. (For example, Terminal → Preferences means to select the Preferences item from the Terminal’s menu bar.)

Unix Commands

We introduce each main concept first, then break it down into task-oriented sections. Each section shows the best command to use for a task, explains what it does, and shows the syntax (how to put the command line together). The syntax is given like this:

rm filename

Commands appear in constant width type (in this example, rm). You should type the command exactly as it appears in the example. The variable parts (here, filename) will appear in constant width italic type; you must supply your own value. To enter this command, you would type rm followed by a space and the name of the file that you want to remove, then press the Return key. (Your keyboard may have a key labeled Enter or an arrow with a right-angle shaft instead of a Return key.) Words in regular italic are new terms. Finally, keyboard combinations are indicated with a hyphen; for example, “Control-X” means to hold down the Control key and the X key at the same time. The letter appears capitalized in the book, but you do not have to capitalize it as you type.

Examples

Examples show what should happen as you enter a command. Some examples assume that you’ve created certain files. If you haven’t, you may not get the results shown.

We use typewriter-style characters for examples. In code samples, items you type to try the example are boldface. System messages and responses are constant width.

Here’s an example:

% date
Mon Feb  4 16:17:25 PST 2002
%

The character % is the shell (system) prompt. To do this example, you would type date and then press Return. The date command responds “Mon Feb 4 16:17:25 PST 2002” and then returns you to the prompt.

Text you see in examples may not be exactly what you see on your screen. Sometimes we edit screen samples to eliminate distracting text or make them fit the page.

Problem Checklist

We’ve included problem checklists in some sections. You may skip these parts and go back to them if you have a problem.

Exercises

Some sections have exercises to reinforce the text you’ve read. Follow the exercises, but don’t be afraid to experiment on your own.

Exercises have two columns. The lefthand column tells you what to do and the right-hand column tells you how to do it. For example, a line in Section 1.2.1 near the end of Chapter 1 shows the following:

Get today’s date.

date

To follow the exercise, type the word date on your keyboard and press the Return key. The lefthand column tells you what will happen.

After you try the commands, you’ll have a better idea of the ones you want to learn more about. You can then get more information from Section 10.1.