Downloading and Preparing Files

One of the best things about the Web is that you can download files from it. These files can be applications, graphics, MP3 files, text files, updaters, or any other file you can think of. Downloading files is simple; the only two areas that might give you some trouble are finding the files you download and preparing them for use.

The general process for downloading and preparing files is the following:

  1. Locate the file you want to download.

  2. Download the file to your Mac.

  3. Prepare the file for use by decoding and uncompressing it.


Because of Mac OS X's Unix underpinnings, this step can be a little more complicated than it has been in past versions of the OS. Fortunately, most of the time, this process is relatively automatic. You have to intervene manually only infrequently.

There are two basic ways to download files. You can use a Web browser to download files, or you can use an FTP client (or the Finder) to download files from FTP and other sites. Using a Web browser to download files is simpler, but it is also slower. A dedicated FTP client can dramatically speed up file downloading.

For information on using the Finder to download files from an FTP site, see "Downloading Files Via FTP in the Finder," p. 420.

For information about configuring and using the Interarchy FTP application, see "Downloading Files Better with Interarchy," p. 420.

Configuring a Downloads Folder

By default, your Web browser stores files you download in the Desktop folder in your Home directory (and thus, they appear on your desktop). If this isn't where you want downloaded files to be stored, you should create a folder into which your Web browser will always download files. That way, you will always know where to find the files you download and they won't clutter your desktop.


Because a directory is modified when you store files in it, you must use a directory that you have permissions to write to. On your Mac OS X startup volume, you are limited to downloading files to a directory within your Home directory. However, you can choose a location outside your Mac OS X startup volume if you want.

If you want other users of your machine to be able to access the files you download, you can use your Public folder as your downloads folder.

After you have created your downloads folder, open the General pane of the Safari Preferences dialog box and use the "Save downloaded files to" pop-up menu to choose that folder.

Downloading Files Using Safari

Downloading files is as simple as anything gets on the Mac. Safari uses its Downloads window to show you information about the files you are downloading. To start the download process, just click the download link for the file you want to download.


You can download multiple files at the same time. Start one; then, move back to a Web window, move to the next, and start it downloading.

You can also continue to browse the Web while your files are downloading. The speed decreases a bit (or a lot if you are using a dial-up Internet account), but at least you can do something while the file is downloading.

Some sites simply provide the file's name as its link, whereas others provide a Download button. Whichever way it is done, finding the link to click to begin the download process is usually simple.

After you click the link to begin the download, the Downloads window opens showing the progress of the file you are downloading (see Figure 13.17). As a file is downloaded, you see its name, the download progress, and the file size. During the download process, you see the stop button for the file you are downloading; you can stop the process by clicking this button.

Figure 13.17. The Downloads window provides the information and tools you need to manage your downloads.



A quick way to switch windows is by pressing graphics/mac.gif-~. This is a good way to jump between the Downloads window and your other Web windows. You can also move directly into the Downloads window by pressing Option-graphics/mac.gif-L.

When the download is complete, you see the file's icon. Also, the Stop button becomes the Find in Finder button, which contains a magnifying glass. Click this button to open the file you downloaded in the Finder.


If the download process is interrupted for some reason (such as a connection problem or if you clicked the Stop button), the Stop button becomes the Retry button, which contains a circular arrow. Click this button to try to download the file again.

As you download files, Safari continues to add them to the list in the Downloads window. You can clear them manually by clicking the Clear button. You can have Safari remove them automatically by selecting either When Safari Quits or Upon Successful Download on the "Remove download list items" pop-up menu on the General pane of the Safari Preferences dialog box.

After the download is complete, Safari tries to prepare the file that downloaded so you can use it. Most of the time, this works automatically, but in some situations, you must perform this task manually. This process can be somewhat complicated depending on the file you download.

Preparing Files for Use

Most files you download are encoded and compressed. Encoding is the process of translating an application or other file into a plain-text file so it can be transferred across the Internet. Compressing a file is a process that makes the file's size smaller so it can be transferred across the Internet more quickly.

Before you can use a file you have downloaded, it must be decoded and it might also need to be uncompressed. Depending on the type of file it is, these two actions might be done at the same time or might have to be handled separately. An application is required for both tasks; a single application can usually handle them, but occasionally the file might need to be uncompressed with one application and decoded with another.

Understanding File Extensions for Compressed Files

Knowing what will happen in any situation requires that you understand the types of files you are likely to download. You can determine this by the filename extension. The most common extensions with which you will have to deal are listed in Table 13.1.

Table 13.1. Common File Extensions for Compressed or Encoded Mac Files

File Extension

What It Means



Binary file format

A common encoding format for the Mac.


Unix compression format

The dominant compression format for Unix files.


Binhex encoding

Another very common encoding format for the Mac.


Disk Image file format

A file that is a disk image and must be mounted with the Disk Utility application before it can be used.


The package format

Package files are installed with the application installer.


StuffIt compression format that can be uncompressed by double-clicking the file

Useful because the recipient of the file doesn't have to have a decompression tool. He simply double-clicks the file to decompress it.


StuffIt compression

The standard compression for Mac files.


Tape Archive format

An archiving format for Unix computers that is used for some files you might want for Mac OS X.


Zip compression format

The dominant compression format for Windows PCs.

Aladdin's StuffIt application is the dominant application for compressing, uncompressing, decoding, and encoding Mac files. The freeware application StuffIt Expander is included with Mac OS X to enable you to deal with compressed and encoded files you download. StuffIt Expander can handle almost all the file formats listed in Table 13.1. So, most of the time, you will use StuffIt Expander to prepare the files you download for use. Safari or other tools with which you download files typically handle this process for you automatically.

Because Mac OS X is based on Unix, you can use files that use the .tar and .gz formats as well. Preparing these files can be a bit more complicated (if StuffIt Expander doesn't work) because you have to use Unix commands to prepare them.

To learn how to use Unix commands to prepare a file you have downloaded, see Chapter 9, "Unix: Working with the Command Line," p. 243.

Manually Preparing a File for Use

Although you can rely on Safari's preconfigured helper applications to handle most of the files you download, it is useful to know how to manually decode and uncompress files you download so you can handle them yourself and better understand how to configure a helper application to do it for you.

By default, Safari attempts to launch the appropriate helper application to handle files you download. If a file you download can be handled successfully by the helper application, it is prepared and a usable version of it is placed in the same folder into which it was downloaded.

To manually prepare a file, use the following steps:

  1. Locate the file you want to uncompress or decode.

  2. Access the StuffIt Expander application by opening the following path: Applications/Utilities.

  3. Drag and drop the file you want to prepare onto the StuffIt Expander icon. The StuffIt Expander application launches, showing a progress bar for the processing of the file.


If the StuffIt Expander icon doesn't become highlighted when you drag a file onto it, that file type cannot be handled with the free version of the StuffIt application. If the file is a Unix file, use the Unix tools to prepare it. Otherwise, you will probably have to upgrade to StuffIt Deluxe to be able to work with the file.

When the process is complete, you see a new item in the same folder as the file you downloaded. If the original file contained more than one item, you see a new folder containing the decoded and uncompressed items instead of a file.

You can work with the uncompressed/decoded items just like any other items on your Mac. For example, if a file expands into a folder, you can open that folder to work with the files in it. If the file expands into a .img file, you can double-click that file to mount the disk image on your Mac; often, these files are mounted automatically after they are processed.


You can also prepare a file by launching StuffIt Expander and selecting Expand from its File menu.

For almost all the files you download, even the manual process is just that simple. Occasionally, you might run into a file on which this process doesn't work. In such a case, you have to try another tool (such as a Unix command or the StuffIt Deluxe application).

Configuring StuffIt Expander

A bit of configuration of StuffIt Expander will make this process even less difficult:

  1. Open the StuffIt Expander application.

  2. On the StuffIt Expander menu, select Preferences (graphics/mac.gif-,) to open the Preferences window. This window has a toolbar in which you select the panes you want to view in the lower part of the window. Some of the options you might want to configure are listed in Table 13.2.

  3. After you configure your preferences, click OK.

Table 13.2. Useful StuffIt Expander Preferences

Group of Options

Useful Settings


Check the "Delete after expanding" check boxes if you want the application to delete files it has expanded. This can prevent your downloads folder from being cluttered with files you don't need (not to mention saving your disk space).

Use the Scan for viruses using pop-up menu to set an application that StuffIt Expander will use to check files you expand for viruses.

Disk Images

Use these controls to have the application automatically mount disk image files.


Use the Destination controls to set a folder into which expanded files should be placed. For example, you can set files to expand into a specific folder or have the application prompt you for a folder location each time it expands a file.

Watch Folder

Use these controls to identify a folder StuffIt Expander should watch. When it finds a compressed or encoded file in this folder, it automatically expands the file. For example, you can set your downloads folder to be the watch folder so files there are handled automatically.


Use these controls to determine which file types StuffIt Expander handles. Click the "Use StuffIt Expander for all available file types" button so the application will work with as many file types as possible.

    Part I: Mac OS X: Exploring the Core
    Part III: Mac OS X: Living the Digital Life