Mac OS X Bundles

Most Mac OS X files are actually bundles. If you try copying and pasting bundles outside of OS X, they will copy in segments, ie: each piece of the bundle.

This can cause unexpected behavior when uploading or emailing files that are actually bundles.

Understanding bundles

Native Mac OS X applications, such as Pages, Keynote, and GarageBand, all save as bundles. However, at first glance, it doesn’t look like a bundle. It looks like a regular file. To the novice user, this can be confusing.

Here is an example of how each file name would appear when saving from certain Mac OS X native applications:

• Pages: my-doc.pages
• Keynote: my-presentation.key
• GarageBand: my-song.band
• Dashboard: my-widget.wdgt

These are just sample file names, but notice each extension.

When copying and pasting these files to other directories within OS X, the file package is retained. To the user, it appears as if they just copied a single file. However, if you attempt to email, upload, or otherwise move the file to another operating system outside of OS X, the package de-assembles itself.

Revealing bundles

To make sense of this idea, just consider native Mac OS X files as folders. Essentially, that’s what they are. Folders with files inside.

To make sure a file is actually is bundle, you can easily check using the Finder. Right-click on a file and choose “Show Package Contents”.

Another Finder window should then open up, revealing the contents contained within the bundle.

Compressing bundles

Normally when emailing or uploading folders, you have to either attach each individual file one at a time, or compress the entire folder into a zip file, for example. For the case of bundles, compressing is the best option, since there could be dozens of files contained within, as well as installer packages that would be difficult to transfer.

In the Finder, right-click on a bundle, and choose “Create Archive of …”

This will immediately create a zip file of the entire bundle, which can be emailed or uploaded easily.