Mac OS X Panther in a Nutshell, 2nd Edition

Chapter 1. Using Mac OS X

There are actually two interface layers to Mac OS X. One is Aqua , the system’s native graphical user interface (GUI); the other is a command-line interface (CLI), which is most commonly accessed via the Terminal application (/Applications/Utilities). This chapter provides a quick overview of Mac OS X’s Aqua environment; later chapters in the book will introduce you to the Terminal and the BSD Unix side, with a full examination of these deeper OS layers in Part IV.

Mac OS X offers a feature-rich graphical user environment that makes it easy for people to interact with the operating system. This chapter starts out with a discussion of Mac OS X’s Desktop, and introduces things like the menu bar, the Dock, and basic window controls. Chapter 2 covers the Finder, Mac OS X’s file manager.

Starting Up and Logging In

When you turn on your Mac (or restart it), it takes a minute or so for the system to start up. During this time, various processes and services are started before the user is presented with a login window. Unix veterans are used to seeing the startup phase displayed as a cascade of text messages spilling down the screen, but Mac OS X hides all this information behind a plain white screen with a gray Apple logo on it.

Tip

You can see all that startup text if you really want to, by booting into single-user mode (hold down -S as your Mac starts up). This can be a useful diagnostic tool for hardcore Unix-heads who know what they’re doing, or a way for the merely curious to watch the strange sight of their Mac rolling out of bed and stumbling around in pure-Unix mode before it puts on its Mac OS face. Use the exit command at the single-user shell to resume the normal Mac OS X boot process. You can also view some of the machine’s startup messages after the fact by looking at the file /var/log/system.log; only users with admin privileges can read this file.

Eventually the system either settles on the login screen or logs in a specific user, depending upon the machine’s configuration (System Preferences→Accounts→Login Options). If presented with a login screen, you need to provide your username (either by choosing it from a list or typing your username into a text field) and password.

Once you’ve successfully logged in, Mac OS X loads your user account and presents you with your Desktop using the settings you’ve provided in System Preferences. You are now in your Home folder.

Generally speaking, everything in your Home folder (which you can always go to through the Finder’s Go→Home (Shift--H) option) belongs to you, and you are unrestricted in how you read, modify, create and delete the files and folders within it (and the files and folders within those folders, and so on). Everything outside your Home folder is another matter. For example, all users can run the applications stored in the /Applications folder, but only admin users can modify that folder’s contents; no regular user, admin or otherwise, has full access to any other user’s Home folder. See Chapter 8 for more information on the structure of Mac OS X’s filesystem and permissions.