Today I needed to view the contents of OS X's SDKs, which are published as .dmg's.
To my surprise, I discovered that the structure is as follows :
- The .dmg contains a hidden .pkg files
- The .pkg files contain a Payload file, which is a .gz or a .bz2, depends
- The .gz contains a single cpio-compressed file
- This cpio archive contains all the files.
Can anybody provide technical and/or historical reasons why this is done this way ?
Just to be clear : I don't have any technical problem, I'm just curious.