Getting File Information
The Mac OS has always returned a wealth of information about a file via the Get Info option from the Finder's File menu. In Mac OS X, this is no different. Unlike Mac OS 8/9, the Mac OS X Info window can display a great deal more information about your files and folders, such as graphical previews and user permissions.
Let's take a look at each one of the views, the information it contains, and what it means to you.
The default Get Info window can be displayed by selecting the file you want to examine within the Finder, and then choosing Get Info (Command+I) from the File menu. As shown in Figure 3.22, the initial information window provides basic facts about the selected resource. The Get Info window can display additional information about a selected resource by expanding hidden portions of the window via the disclosure arrows located along the bottom of the window.
Figure 3.22 The General Information panel provides basic size/location/type information about a file.
Selecting a file and choosing Get Info displays data about that file, and has several options for revealing additional information:
KindThe type of file being examined (application, movie, and so on).
SizeThe size of the file or folder.
WhereThe full path to the selected resource.
CreatedThe day and time the item was created.
ModifiedThe day and time the item was last modified.
VersionThe version of the document. Usually available only on application files.
Stationery PadAvailable for document files only. If the Stationery Pad check box is checked, the file can be used to create new files, but cannot be modified itself. This is used to create template files for common documents.
LockedIf this option is checked, the file cannot be modified or deleted until it is unlocked. For Linux/Unix users, this is equivalent to setting the immutable flag for the file.
If the file you are viewing is an alias file, the General Information panel will also show the location of the original file along with a Select New Original button that lets you pick a new file to attach the alias to.
If you're unhappy with the icon of the resource you're examining, you can click the object's icon within the General Information panel, and then use the Copy and Paste options in the Edit menu to move icons or images from other files onto the selected item. The Cut option can be used to remove a custom icon from a file and restore the default.
Name & Extension
Mac OS X shares something with Windows: file extensions. Although it is still possible for files to have the traditional Macintosh file types and creators, it is no longer the norm. To shield users from the shock of seeing extensions to the names of their files, Apple added the option to hide file extensions in Mac OS X. Users can turn off this option on a file-by-file basis by accessing the Name & Extension portion of the Get Info panel, as seen in Figure 3.23.
Figure 3.23 The Name & Extension panel can hide or reveal file extensions.
To edit the filename itself (including the extension) make modifications within the Name & Extension field. Turn on (or off) file extensions by clicking the Hide Extension check box.
Mac OS X will function identically whether or not file extensions are visible. This is simply a change in appearance, not functionality.
When you're getting info on a folder, the Content Index option is available, as demonstrated in Figure 3.24.
Figure 3.24 Index folder contents for quick searches.
Using the Index Now button, you can index a folder's contents so that the Finder's "Find" function can quickly search for text within the folder's files. You must index a folder before you can perform a content search.
Click the Delete Index button to remove an index that is outdated (because you've removed/changed files within the folder), or that is no longer needed.
If you have selected a document icon (not an application or a folder), you should be able to access the Open With panel within the Get Info window. This is used to configure the applications that open certain types of documents on the system. Unlike previous versions of Mac OS, which relied on a hidden creator and file type, Mac OS X can also use file extensions or creator/file-type resources. If you download a file from a non-Mac OS X system, your computer might not realize what it needs to do to open the file. The Open With pane, shown in Figure 3.25, lets you configure how the system reacts.
Figure 3.25 The Open With option allows you to choose what application will read a particular file or type of file.
The default application name is shown at the top of a pop-up menu containing alternative application choices. If the application you want to use isn't in the menu, choose Other, and then use the standard Mac OS X file dialog to browse to the application you want to use.
If you have a group of files that you'd like to open with a given application, you can select the entire group, and use the Open With settings to adjust them all simultaneously. Alternatively, click the Change All button to set the default application for all files of that type on your system. This beats selecting each file and making the setting individually.
If you have an application selected, you might be able to choose Languages within the Get Info window. Applications can have multiple internal resources that adjust the application to the appropriate system conditionsthe Language panel allows you to adjust the language resources used by an application.
In early versions of the Mac OS, resources were contained within a file's resource fork. Unfortunately, resource forks are unique to the Mac file system. To store Mac files and applications on a non-Mac file system, various contortions had to be made. Typically, the data portion of an application would be stored like a normal file, and the resource fork would be converted to a second file that was stored elsewhere.
Although this has worked for many years, it requires computers that interact with Mac files to understand the unusual quality of Mac files. In Mac OS X, files can still have resources, but they have been bundled in an entirely new way. First introduced in Mac OS 9, the Mac OS now supports a new concept called a package. A package is nothing more than a folder structure that appears to the user to be a single file. In reality, a package is a folder that contains individual files for all the resources it might need. Other operating systems need not understand the specifics of the Mac file system to store package files. The Languages panel, shown in Figure 3.26, displays the language resources available for each application, allowing a user to immediately localize software with the appropriately packaged resources. The Add and Remove buttons can be used to add additional language resources to the software.
Figure 3.26 Language resources can be examined in this view.
Although only language resources are shown in the current version of Mac OS X, you might find interesting things appearing in the future. When NeXT Computer was shipping OpenStep, the operating system could run on multiple CPU architectures, such as x86, Motorola 68000, and Sparc. Applications for OpenStep could contain resources for each of the different CPUs, allowing a single application file to run unchanged on multiple different computers.
Even though Intel support for Mac OS X is currently only a dream (or a behind-closed-doors reality), it is possible that Apple might reintroduce this feature in the future.
If a QuickTime-recognized document is selected, there will be another available Get Info option: Preview. Preview provides a quick look at the contents of a wide variety of media files including MP3s, CD audio tracks (aiff), JPEGs, GIFs, TIFFs, PDFs, and many, many more.
If you are previewing a video or audio track, the QuickTime player controls will appear and enable you to play the contents of the file. This is a great way to play your CDs or listen to MP3s without starting up a copy of iTunes. Figure 3.27 shows a CD audio track being played in the Preview panel.
Figure 3.27 Play your CD tracks using the Finder's Get Info Preview panel.
Ownership & Permissions
Mac OS X enables you to take control over who can view your files. Without your password (or the system administrator [root] password), other users can be completely restricted from accessing your folders and files. Choose the Ownership & Permissions panel of the Get Info window after selecting the file or folder you want to adjust. Your screen should look similar to Figure 3.28. Click the lock icon to make changes.
Figure 3.28 File and folder permissions can be set in the Ownership & Permissions panel.
There are three levels of access you can adjust:
OwnerThe person who owns a file. Most files on a default Mac OS X installation are owned by a system user. You own files that you create.
GroupThe default OS X group is Staff, and all members of the operating system are part of the Staff group. Chapter 24, "User Management and Machine Clustering," discusses the creation of additional groups.
Others Users who are not the owner and not part of the default group. Because all Mac OS X users are part of the Staff group, you shouldn't have to enable access to everybody else unless you are creating a customized, multigroup system.
For each of these levels of access, there are multiple user rights. Adjusting these rights controls what the owner, group, and everyone else can do to a file or folder:
Read OnlyThe file or folder can be read but not modified in any way.
Write Only (Drop Box)Available only as an option for folders, write only access allows users to add files to a folder, but not to read what is inside the folder.
Read & WriteThe file or folder can be read, written to, or deleted.
NoneThe file or folder may not be read, written to, deleted, or modified in any way.
When viewing the file information for a folder, the window will also show an Apply to Enclosed Items button that will copy all the access rights on the folder to the files underneath. If a folder does not have read permissions, the files inside the folder may still be accessed or modified unless they too have read-only permissions.
A final setting exists for storage volumes. If a disk is selected while viewing privilege information, an Ignore Ownership on This Volume check box will appear. Clicking this box will cause the volume to appear as wide open to the operating system. Users can modify anything on the drivejust as in previous versions of the Mac OS. Activating this setting is not recommended.
The final area within the Get Info window, Comments, provides a text field for you to enter comments about the selected file. Some applications generate file comments automatically to help you remember where the file was downloaded, and so forth.
By default, the Get Info window opens a separate window for each item you request information about. To display a single "inspector-style" window that switches as you move between items, use the Show Inspector option that appears in the File menu when you hold down Option.