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1 December 2006
In the last installment of this series, we looked at OS operations. In order to understand how to best handle Mac OS X, we have to understand how Apple combined a UNIX operating system with a GUI that anyone can use. That integration has few visible artifacts, but it does create certain operational considerations that we have to understand in order to keep from going astray. Being knowledgeable and efficient about these operations is the road to Mac literacy.
In this segment, we'll talk about applications. An application, sometimes just called an "app," is a software program that performs a coherent collection of tasks. For example, a word processor or a Web browser.
In the old days, an application was a single executable file. You'd type its name on the UNIX command line, and it would launch. The operating system would take care of positioning the application somewhere in free memory, protect it from being stepped on by other applications, and would manage the input and output to the user.
In UNIX, in contrast to user applications, there are some background programs that handle system tasks, such as time keeping, networking, activity logging and so on. They are faceless because they have no traditional user interface. They are called daemons. Note that this term is an ancient Greek word related to our concept of a guardian angel. It has nothing to do with a demon.
Nowadays, applications are much more complicated. They require an entire UNIX directory (the same as a Mac OS X folder) to contain all the files, such as, a manual, help files, property lists, icons, audio files, localization files for other languages, and finally, a binary executable. Since everything the application needs can be located in this directory, Apple decided to do something very elegant in the design of Mac OS X and make the directory's icon appear to be a simple file -- one that can be dragged, copied, and double-clicked. Also, every application ends with the file extension, appropriately enough, .app. You'll see this if you elect to show file extensions as we described last week.
It's the responsibility of Mac OS X to dig into this directory when it's double clicked and, using protocol, find the executable and launch it. If you'd like to see the structure and content of one of these applications, do this. Navigate to the root of your hard disk in the Finder. You'll see a directory called Applications. Open it and select (highlight) the application called Chess. Now either right click it -- if you have a multi-button mouse -- or hold down the CTRL key as you click on the icon. You see what's called a contextual menu. Select the menu item called "Show Package Contents." You can further explore the directory structure by opening the directory called MacOS. You'll see a file called Chess. That is the true, naked binary. You could even double click that file to launch the application yourself. (As opposed to double-clicking the directory icon we first looked at.)
In general, you should never, ever change or delete one of these files inside the application directory. The developer placed them there, and the application will probably fail to run correctly if you disturb these support files.
Operations with ApplicationsWhen you bought your Macintosh, Apple pre-populated the Applications Directory with a lot of fun and useful Applications such as the Address Book, Calculator, Mail, Safari, and a text editor. There may also be a few applications such as the iLife suite or the Microsoft Office suite that you can try out and then pay for. In time, you may purchase software that instructs you to copy an application folder into the Applications directory.
The best kind of application is a single folder that is simply dragged to the Applications folder. That is, if you have sufficient system privileges. One of the operational features of a UNIX OS that comes to bear here is whether you are the administrator of your own computer or whether the Mac has been provided to you, say in the workplace, and you are an unprivileged user. Only a Mac OS X administrator can copy applications into the system's Application directory. However, unprivileged Mac OS X users can have their own Application directory in the root of their home directory -- if there isn't one there already. Just navigate to your home folder and use the Finder's File menu to create a New Folder. Rename it "Applications". It will automagically inherit the cool ruler, pencil and brush icon.
In some cases, applications require files to be placed in other places in the Mac's directory structure. The system's or your home folder's Library directory is a candidate. These files may be license files or supplemental code that adds some kind of functionality in support of the application. Rather than have the user drag these files to where they belong, the developer provides what's called an installer package. It will look like a small box/package and have the extension .pkg. For the curious, this is really another directory that contains all the files required to install and a Perl script to move all the files where they belong.
Mac OS X, as part of its security protocols, protects these Library directories from non-administrators. As such, the installer package may ask you for an administrator password. You either defined this when you first configured your Mac out of the box, or you'll need to ask the owner/administrator to enter it for you. (Note: they may politely decline.) What you need to know is that once this administrator password is entered, the installer package can pretty much have its way with your Mac. (Almost.)
As a literate Mac user, we want to be very careful about this. Only give that password to an installer package that you trust. That is, software that you bought from a reputable vendor or shareware developer. If in doubt about shareware, go to Version Tracker, look it up, look at the number of downloads, and read the feedback to get a feel for the popularity, robustness, and reputation of this software. If in doubt, don't install it.
Apple ApplicationsTo wrap up this part, let's look at some of the Apple supplied applications that you should be familiar with.
Address Book. The Mac OS X address book doesn't stand alone. It can feed information to the Apple Mail and Calendar (iCal) applications. It can also display phone numbers in large type so that you can practically dial from across the room. It can print out highly customizable address book lists. It's a great application.
Calculator. Apple's OS calculator was a bit of a joke for many years because it was so limited. The Mac OS X calculator launches as something resembling a simple four-function calculator, but is, in fact, very capable. Go to the Calculator's View menu and select View -> Scientific. For those of you who love the old Hewlett-Packard RPN scientific calculators, you can select an RPN option.
iTunes. This is a legendary application. There is really nothing else like it. Whole books have been written about it, so I won't go into detail. Just be sure that if you have an older Mac that it supports the hardware requirements for iTunes 7 -- which is very graphic intensive.
Mail. In Mac OS X, you get a fairly nice e-mail program called, simply, Mail.app. It's good enough for individuals and robust enough for all but the most severe business environments. You can select an option to have it auto-complete addressees from the Address Book. You may elect to use another e-mail program such as Eudora or Thunderbird, but it's a good idea for beginners to Mac OS X to stick with the Mail.app for awhile. You're guaranteed that the maker of you computer is also the one looking out for your e-mail life's safety and security -- including automatic updates.Preview. Preview is an easily overlooked application. It is a very capable viewer for all kinds of graphics files, including Adobe PDF, and JPG, TIF and PNG image files. And it will even convert from one file type to another. Add this one to your dock along with all the others mentioned here. Use it to view just about any kind of file in Mac OS X.
Safari. The most important applications on your Mac are probably e-mail and your Web browser. Apple's Web browser, Safari, is very good and well integrated into the security infrastructure of Mac OS X. There is little reason to use a different browser unless you have difficulties with certain Web sites that you really need -- such as banking sites. In that case, try Firefox for Mac OS X. In general, however, stick with Safari as a beginner until you have enough experience to select another browser with good reason.
There are many more useful applications for Mac OS X, and a discussion could fill a book. Basically, you want to remember the cautions about assessing and installing applications and keeping them organized in just your system and/or personal application directories.
This is Warp Core column #85. The Warp Core archives are here:
Year 2006* Your humble author also writes a column for TMO.
John Martellaro is a senior scientist and author. A former U.S. Air Force officer, he has worked for NASA, White Sands Missile Range, Lockheed Martin Astronautics, the Oak Ridge National Laboratory and Apple Computer. During his five years at Apple, he worked as a Senior Marketing Manager for science and technology, Federal Account Executive, and High Performance Computing Manager. His interests include alpine skiing, SciFi, astronomy, and Perl. John lives in Colorado. He can be contacted via his Website or the Applelinks Contact link.
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