Tài liệu Opening Mac OS X Programs pdf

5.1. Opening Mac OS X Programs
You can launch (open) a program in any of several ways:
• Click a program's icon on the Dock, the Sidebar, or the Finder toolbar.
• Use Spotlight. Hit -Space bar, type the first letters of the program's name, and
then press Return or Enter.
• Double-click an application's icon in the Finder.
• If you've added the Applications folder to your Dock (or, better yet, a folder
containing aliases of only the programs you use), click the Dock icon to open the
stack (Section 4.2.2
). Then click the program you want (or even type the first few
letters of its name and then press Return).
• Highlight an application icon and then press -O (short for File Open) or
-down arrow.
• Use the submenus of the menu's Recent Items Applications command.
FREQUENTLY ASKED QUESTION
What's with the Big "Duh"?
So, I've just installed Leopard, I'm all excited, and I double-click an Excel
document. And now the Mac asks me: "You are opening Microsoft Excel for the
first time. Do you want to continue?" Well, HELLO! I double-clicked the icon,
didn't I? Does Apple think I'm some kind of idiot?
It's not you Apple's worried about. It's the silent parade of evil hackers, lurking
out there in Internet Land, waiting for the right moment to bring down the Mac.
See, in the Windows world, spyware authors have to be sneaky about how they
install their stuff on your PC. You wouldn't be so stupid as to double-click an
application called Spyware Installer™, of course. So the spyware tricks you into
running its installer. It commandeers a certain document type (like MP3 or
JPEG), reassigning it to its installer. You innocently double-click some
document, but an unanticipated program opens—and you've just opened
Pandora's box.
In Mac OS X, that can't happen. When double-clicking some document opens a
program for the first time, this dialog box appears, just to let you know what's

about to happen. If the program that's about to open isn't the one you were
expecting, well, you've got a chance to back out of it.
And if it is the program you were expecting, click Continue. You won't be asked
again about this version of this particular program.
•
•
• Note: Mac OS X stores a list of your recently used programs in a text file called
com.apple.recentitems.plist, located in your Home folder Library
Preferences folder. And with about $1.00, that information will buy you a cup of
coffee in most restaurants.
•
• Open a document icon in any of these ways, or drag a document onto the icon of a
program that can open it (whether in the Dock, the Finder toolbar, the Sidebar, or
in a folder window).
FREQUENTLY ASKED QUESTION
Virtual Memory and Memory Allotments
I'm completely at sea when it comes to using memory in Mac OS X. There's no
Memory control panel. There's no box to set the memory allotment in the Get
Info dialog box of any program. There's no on/off switch for virtual memory.
There's no RAM disk option. There isn't even an About This Macintosh box that
shows where all my RAM is going. What on earth is going on?
Mac OS X handles memory with light-years more sophistication and skill than
anything Mac fans have used before—so much so, in fact, that these controls no
longer even exist.
In the old days, each program claimed a fixed amount of RAM for itself as soon
as you launched it. You could view and adjust this number in the program's Get
Info box. When you launched a program, it instantly claimed 20 MB of memory
(or whatever its programmers thought it might need).
But in Mac OS X, memory allotments are dynamic. They adjust themselves as
needed, on the fly. When you launch a program, it might not use very much

RAM at all. But when you then use that program to open a huge, complex
document, the system supplies more memory automatically. Then, when you
close that document, Mac OS X automatically returns the RAM it was using to
the pot, so that it's available for use by other programs and functions.
It's true that the About This Mac command no longer opens a little graph
depicting how much RAM each program is using, as it did in Mac OS 9. There's
no longer much point. The answer is always, "Exactly as much memory as it
needs, and it's changing minute by minute."
Still, if you're desperate to know how much memory each of your running
programs is using at this instant, open your Applications Utilities folder.
Open the program called Activity Monitor. It presents a table showing what
percentage of your Mac's memory each running program is using.
Then there's the matter of virtual memory, which helps you open more programs
simultaneously than should fit into the amount of RAM (electronic memory)
your computer has. This feature works by using a chunk of hard drive space as
temporary overflow RAM when necessary. Of course, real memory delivers
information to your Mac's brain many times faster than the hard drive, which is
why virtual memory has a reputation for sluggishness.
In Mac OS X, virtual memory is turned on all the time. But these days, it doesn't
slow down your machine much, for a couple of reasons. First, each program
uses only as much RAM as it needs to begin with, so far less is wasted. Second,
virtual memory in Mac OS X puts only pieces of your programs onto the hard
drive, minimizing the slowdown effect. In any case, even if you have 50
programs open, Mac OS X devotes much of your Mac's actual RAM to
whatever program is frontmost, so the active program doesn't grow sluggish.
You'll notice the sluggishness kicking in only when switching programs or
when working on an absolutely huge document that overwhelms your installed
RAM. (Want to see how much virtual memory has kicked in? Mac OS X can
show you. See Section 16.8.5.6 for instructions.)
Therefore, "out of memory" messages are unheard-of in Leopard. You may,

however, be alerted that your hard drive is running out of space, thereby
thwarting the efforts of Mac OS X's virtual memory scheme. Make more
room—or install more RAM.


Tip: If you press Option as you open an application (or anything else) in the Finder, you
automatically close the window that contains its icon. Later, when you return to the
Finder, you'll find a neat, clean desktop—no loitering windows.

When you launch a program, the Mac reads its computer code, which lies on your hard
drive's surface, and feeds it quickly into RAM (memory). During this brief interval, the
icon of the opening program jumps up and down eagerly (or just blinks eagerly; see the
tip on Section 4.3.4
) in your Dock.

Tip: Want to see multithreading in action? Launch a program that takes a long time to
open—that is, whose icon in the Dock does a lot of bouncing.You don't have to wait for
the application to finish bouncing—you're wasting perfectly good computing time. Just
switch to another program and get to work; the newly opened program keeps right on
launching in the background. Multithreading means that Mac OS X can crunch more than
one process at a time.

What happens next depends on the program you're using. Most present you with a new,
blank, untitled document. Some, like iDVD, automatically open the last file you worked
on. Some, like FileMaker and PowerPoint, ask if you want to open an existing document
or create a new one. And a few oddball programs don't open any window at all when first
launched.
5.1.1. The Application Menu
In each case, however, the very first menu after the appears with bold lettering and
identifies the program you're using. It might say iTunes, or Microsoft Word, or Stickies.

This Application menu (Figure 5-1
) offers a number of commands pertaining to the entire
program and its windows, including About, Quit, and Hide.
Figure 5-1. The first menu in every program lets you know, at a glance, which
program you're actually in. It also offers overall program commands like Quit and
Hide.



5.1.2. Quitting Programs
You quit a program by pressing -Q, the keyboard equivalent of the Quit command.
(In Mac OS X, the Quit command is at the bottom of the Application menu.)
But Mac OS X offers two much more fun ways to quit a program:
• Control-click or right-click a program's Dock icon and then choose Quit from the
pop-up menu.
• When you've pressed -Tab to summon Leopard's "heads-up display" of open
programs (Section 4.3
), type the letter Q without releasing the key. The
highlighted program quits without further ado.
UP TO SPEED
When Programs Are Actually Folders
You may have noticed that OS X programs don't seem to have 50,000 support
files strewn across your hard drive. To open AOL, you no longer need to first
open an America Online folder; you can just double-click the AOL icon. That's
a much better arrangement than in Mac OS 9 or Windows, where many
programs must remain in special folders, surrounded by libraries, dictionaries,
foreign language components, and other support files and folders.
The question is: Where did all those support files go?
Mac OS X features packages or bundles, which are folders that behave like
single files. Every properly written Mac OS X program looks like a single,

double-clickable application icon. Yet to the Mac, it's actually a folder that
contains both the actual application icon and all of its hidden support files.
(Even documents can be packages, including iDVD project files, iMovie 6 files,
and some TextEdit documents.)
If you'd like to prove this to yourself, try this experiment. Choose Go
Applications. See the Calculator program? Control-click it or right-click it.
From the shortcut menu, choose Show Package Contents. You're asking Mac
OS X to show you what's inside the Calculator "application icon" folder.
The Calculator package window opens, revealing a Contents folder that you've
never seen before. If you open this folder, you'll find a handful of strange-
looking, Unix-named folders and files that are, behind the scenes, pieces of the
Calculator program itself.
The application-as-folder trick is convenient for you, of course, because it
means that you're generally free to move the application to a different
window—or uninstall the program by dragging this single icon to the Trash—
without worrying that you're leaving behind its entourage of support files. It's
also convenient for programmers, because they can update certain aspects of
their applications just by replacing one of these component files, without having
to rewrite the entire program.
You can even try out this programmery benefit for yourself. In the case of the
Calculator and many other Mac OS X programs, the Resources folder contains
individual graphics file—PDF or TIFF files—that serve as the graphic elements
that you see when using the program. For example, the file lcd.tiff in the
calculator's Resources folder contains the image of the calculator's screen
(where the numbers appear as you punch the calculator number buttons).
Using a graphics program, you can change the background of this light-yellow
calculator screen to, say, light blue. The next time you double-click the
Calculator—which you now realize is actually a folder behind the scenes—
you'll see your modified calculator design.

5.1.3. Force Quitting Programs
Mac OS X is a rock-solid operating system, but that doesn't mean that programs never
screw up. Individual programs are as likely as ever to freeze—or, rather, to hang (to lock
up and display the "spinning beach ball of death" cursor). In such cases, you have no
choice but to force quit the program—the computer equivalent of terminating it with a
blunt instrument.
Doing so doesn't destabilize your Mac; you don't have to restart it. In fact, you can
usually reopen the very same program and get on with your life.
You can force quit a stuck program in any of several ways:
• Control-click (right-click) its Dock icon, or just hold your mouse down on it. Once
the shortcut menu appears, press Option so that the Quit command now says Force
Quit (see Figure 5-2
). Bingo—that program is outta here.
Figure 5-2. Top: You can force quit a program from the Dock, thanks to the
Option key.
Bottom: When you press Option- -Esc or choose Force Quit from the
menu, a tidy box listing all open programs appears. Just click the one you
want to abort, click Force Quit, and click Force Quit again in the
confirmation box. Often, you may have to force quit a program twice to make
it really go away. (Using more technical tools like the Unix kill command,
there are other ways to jettison programs. But this is often the most
convenient.)

• Press Option- -Esc, the traditional Mac force quit keystroke.
• Choose Force Quit.
Either way, proceed as shown in Figure 5-2
.
Again, force quitting is not bad for your Mac. The only downside to force quitting a

program is that you lose any unsaved changes to your open documents, along with any
preference settings you may have changed while the program was open.