3. File Systems: Lesson Eleven

Question 1

How do you identify the ownership and permissions of a file or folder in the Finder?

Answer 1

You can use the Info or Inspector windows in the Finder to identify an item’s ownership and permissions.

Question 2

How do ACLs differ from standard UNIX file system permissions?

Answer 2

Standard UNIX file system permissions allow for permissions to be set only for one owner, one group, and all others.
ACLs allow for an unlimited list of permissions entries.

Question 3

What’s the locked file flag?

Answer 3

The locked file flag prevents anyone, including the item’s owner, from editing an item.
Only the item’s owner can unlock the item to then allow modification.

Question 4

Why is the root, or beginning, level of a user’s home folder visible to other users?

Answer 4

The root level of a user’s home folder is visible to other users so they can navigate to the Public shared folder.

Question 5

How does the default organization of the file system allow users to safely share local files and folders?

Answer 5

Every home folder contains a Public folder that other users can read and a Drop Box folder that other users can write to.
All other subfolders in a user’s home folder (except the optional Sites folder) have default permissions that don’t allow access to other users.
The Shared folder is also set for all users to share items.

Question 6

What’s unique about the permissions of the /Users/Shared folder?

Answer 6

The Shared folder is set up to allow all users to read and write files, but only the user who owns an item can delete it from the Shared folder.
This is accomplished using the sticky bit permissions setting.

Question 7

What does it mean when you choose the option to “ignore volume ownership” in the Finder?
What are the security ramifications of ignoring volume ownership?

Answer 7

You can choose to ignore ownership on any nonsystem volume. This will ignore any ownership rules and grant any logged-on user unlimited access to the contents of the volume.
It’s a potential security risk because it will allow any local user account to have full access to the volume, even if that user didn’t originally mount the volume.