OS X DMG Creation from a Folder

Edit: As of OS X Lion (10.7) Applications show up in your services menu, so you get a right click menu for free.

The hdiutil command is awesome. Amongst its many features is the ability to create a DMG file from a specified folder. For some reason, there's no right click option for creating DMG files from folders. Strangely enough, there is a right click compress option that will create a zip, but that's really not sufficient. If you create a zip, you can't access individual files from it like you can a compressed DMG.

Edit: For anyone who just wants the command and not fuss with the scripts, here's how you might create a zip compressed dmg file from a folder called Movies:

hdiutil create -srcfolder Movies -volname Movies -fs HFS+ \
 -fsargs -c c=64,a=16,e=16 -format UDBZ ./Movies.dmg

Once again, I've used Automator to invoke a bash script. Now I can drop folders on my app and generate a compressed, read-only DMG file. I don't have lots of free space, so I use this for applications I've downloaded that come as a tar.gz/tar.bz/zip/whatever.

I'd like to point out that while it is possible to embed all of the bash script content into the Automator "Run Shell Script" feature, but then I wouldn't be able to easily invoke it from the command line and I use the command line alot.

Here's the content of my Automator "Run Shell Script" box (CreateDMGFromFolder.app):


Here's the content of my shell script (CreateDMGFromFolder):

Edit: I've updated the script in light of reading the bash man page. Parameter Expansion is bad-ass.

Here's the new shell script to replace the aforementioned (CreateDMGFromFolder):