Hi b4tn,
Terminal will not concern itself with package contents. They are merely listed as a collection of files within the "Contents" directory for the package you parse.
Using your example, Dock.app...
Terminal output:
[shmenge:~] yash% ls -l /System/Library/CoreServices/Dock.app/Contents
total 24
-rw-r--r-- 1 root wheel 1279 Sep 24 22:09 Info.plist
drwxr-xr-x 4 root wheel 264 Dec 21 09:41 MacOS
-rw-r--r-- 1 root wheel 8 Sep 3 04:51 PkgInfo
drwxr-xr-x 18 root wheel 568 Nov 9 20:07 Resources
-rw-r--r-- 1 root wheel 464 Nov 9 20:07 version.plist