Tutorial: Mac OS X Location Finder: Part 2
Tutorial: Mac OS X Location Finder: Part 2
Ted Landau
September 2007
If it's Tuesday, it must be Frameworks. That's right, this is the second part of the Location Finder tour of Mac OS X (click here to read Part 1). The goal of these two tutorials is to map out "some of Mac OS X's frequently sought-after but not especially obvious destinations." Along the way, you'll discover just how many different yet significant destinations there are in Mac OS X?and hopefully learn a bit more about how Mac OS X works.
Q. Almost all Apple software requires an Installer utility to get the software on a drive. This makes sense for "big" packages, such as a Mac OS X update, that contain multiple applications. But installers are often used even for a single application. Why is this? What is actually getting installed in these cases?
A. The short answer is that even a single application (which isn't really a single file anyway; it's actually a package containing multiple files) may require that additional files be placed in a variety of secondary locations. This is why, for example, that simply copying an application from one computer to another, using the Finder, may result in a copy that fails to work. It fails because the needed support files, that the Installer would have placed, were not copied. In some cases, support files are added automatically, the first time you launch an application, but don't count on this.
So...exactly what are these "support files" and where are their locations? Here's a list of the most common destinations:
Application Support. You'll find this folder in the Library folder of your Home directory. As is often the case with Library folders, there is a similar folder, with the same name, in the main Library folder at the root level of the drive. The difference between the contents of the two folders is that the files in your Home directory affect only your account, while the ones in the main Library affect all accounts on your computer.
Inside these folders are a collection of subfolders each with the name of the application to which it is linked. If you have installed a fair amount of third-party software, you may be surprised to see how many folders there are. For example, my Home directory's Application Support folder contains 139 subfolders, for applications from Acquisition to Webstractor. Each subfolder contains an assortment of files required or optionally used by the relevant application. Among the Apple software items in my Application Support subfolders are: Address Book's contact database; .Mac's Backup utility's settings; and GarageBand's Track and Plug-In Settings.
The main Library's Application Support folder on my Mac contains items such as the themes for iMovie and iDVD, the EyeTV Helper application (which works with EyeTV software) and a host of support files for Adobe software (including a subfolder named Fonts that contains fonts only accessible when using Adobe applications.
If you are looking for accessory files for an application, the Application Support folders should be the first place to check out.
Application Enhancers. Not to be confused with Application Support, this folder (also in your Library folders) contains only the software that works with Unsanity's Application Enhancer. The files here should all have a .ape extension.
InputManagers. This folder (again found in Library folders) contains a strange breed of third-party files that modify the way Mac OS X itself works. For example, FontSight software is stored here (assuming you installed it). This is a program that converts the default plain text display of fonts in Fonts menus into a list where each font name is displayed in its own font. A recent article at MacFixIt (and echoed by a TidBITs article) warned against using virtually any Input Manager software. The primary rationale was that, by mucking around with the way Mac OS X works, these programs can precipitate problems (including freezes and crashes)?because other applications may not peacefully coexist with InputManager modifications. While the potential danger is real, I would not go as far as saying never use an Input Manager. I continue to use FontSight, for example, and have not yet had any associated problems. Still, if you begin to experience otherwise unexplained symptoms, definitely consider InputManagers as a possible culprit.
Internet Plug-Ins. The items in this Library subfolder add features to Web browsers, notably Safari. For example, if you have installed software that allows you to play Windows Media files in your Web browser, you likely have a Windows Media Plugin your Home directory's Internet Plug-Ins folder. In the same named folder in the main Library, the Flash Player and QuickTime plugins are two commonly found items.
Extensions. Located in /System/Library, this folder is populated mainly with software from Apple, installed as part of the initial Mac OS X installation or added later via updates. The extension items, which typically have a .kext suffix (for kernel extension) are primarily used to provide support for hardware peripherals? such as the IOUSBFamily.kext and IOUSBMassStorageClass.kext items (for USB device support) or Apple_iSight.kext (for iSight camera support). An extension named AppleMobileDevice.kext provides support for iPhone.
Occasionally, third party programs install files here. For example, Ambrosia's Snapz Pro screen capture software installs an extension named AmbrosiaAudioSupport.kext in this folder. The item allows you to record audio when making a "movie" with Snapz Pro. If the file is missing, the audio option won't work, even though every other part of Snapz Pro may function normally.
Q. Is there some way I can quickly see all the items that an Installer package will install and where they will go?
A. Yes. Get Pacifist. Use it to open the package file you want to inspect (such as iTunesX.pkg to see what gets installed when you install an iTunes update). The resulting window will give you all the details.
Figure: Pacifist's display.
Q. Where are Mac OS X's built-in screen saver modules and desktop patterns located?
A. Like most of Mac OS X's built-in options, these are in Library folders. You'll find screen saver modules in /System/Library/Screen Savers and desktop pictures are found in /Library/Desktop Pictures.
Q. In Part I of this tutorial, you noted that many Help files for applications are located in the /Library/Documentation/Help folder. However, when I went there to look for the Help files of a particular application, I could not find them. What gives?
A. There is no inviolate rule for where Help files must be located. Essentially, each application determines its own rules. For example, for Microsoft Office, Help files are in the Microsoft Office 2004 folder, in the Office>Help subfolder. In some cases, Help files may be buried within the application package itself. For example, select to Show Package Contents for the iTunes application and navigate to Contents>Resources>English.lproj>iTunes Help. Here is where you'll find the Help files for iTunes. You can even double-click the iTunes Help.html file here to open the Help resource in a Web browser rather than in the default Help Viewer application. At the same time, as shown in the Figure above, iTunes installs Help files for AppleTV, iPhone, and iPod in the /Library/Documentation/Help folder.
Q. Speaking of the iPhone, iTunes creates a backup of certain iPhone content when I sync my iPhone. Where is that backup information stored?
A. You'll find it in the aforementioned Application Support folder of your Home Library. Go to MobileSync/Backup.
On a related note, iPhone and iPod software updates are stored in ~/Library/iTunes/.
Q. When you first set up a new Mac, or completely reinstall Mac OS X, a movie appears with the word "Welcome" in a variety of languages. Where can I find and play this movie file?
A. Appropriately enough, it's inside the Setup Assistant application package. To access it, go to /System/Library/CoreServices and locate the Setup Assistant application. Select to Show Package Contents from its contextual menu and navigate to Contents/Resources/TransitionSection.bundle. Use Show Package Contents again and navigate to Contents/Resources. Here you will find a file named intro.mov. Double-click it and it will load in QuickTime Player. Click to Play and enjoy!
Q. When I launch System Preferences and go to the .Mac pane, my .Mac account name and password are automatically filled in. Where are these data stored?
A. Your account name is stored in an invisible file named .GlobalPreferences.plist. It's located in the Library/Preferences folder of your Home directory. Open it with a plist editing program such as Apple's Property List Editor (as I have covered previously) and search for the property named iToolsMember. You'll see your .Mac name stored there. As for the password, I confess that I am still not sure where that is. But I wouldn't waste much time on it. Wherever it is, it is almost certainly stored in an encrypted format?so even if you located it, you couldn't read it.
Q. I have my Desktop & Screen Saver System Preferences pane set so that the lower right corner of my screen is a Hot Corner to activate the screen saver. Where is the application that launches when the screen saver appears?
A. Go to /System/Library/Frameworks/ScreenSaver.framework/Versions/A/Resources. Here you will find an application named ScreenSaverEngine. Double-click it and your Mac goes into Screen Saver mode immediately.
Q. Could you provide a bit more background about what frameworks are and what is stored in the frameworks folders?
A. Sure. In general, frameworks are Apple's name for program code that is shareable by multiple applications. For example, any program that provides a disc burning feature (such as iTunes or iDVD) is probably getting this functionality from the DiscRecording.framework folder in /System/Library/Frameworks. The /System/Library/PrivateFrameworks directory has a similar sharing function but is restricted to Apple software (hence the "private" designation).
Q. It seems like you could go on listing these odd functions and locations forever. Is there any end in sight?
A. There is a end somewhere, but we have not come close to approaching it. There are a wealth of interesting locations within the System/Library folder that we have not yet begun to explore. The are still some secrets left to uncover in the other Library folders. Then there are the files in the invisible UNIX directories; many of them store settings and data that you use on a regular basis (I noted the contents of the /var folder, for example, in Part 1 of this series). The truth, for better or worse, is that a standard installation of Mac OS X includes over 100,000 files. That's a lot of locations. Consider this tutorial your launching pad. It's now time for you to take over the controls and navigate your way through the remainder of the Mac OS X universe.
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