Change ownership of files to remove need for multiple permissions

Question

In my home (/Users/) folder I have many files migrated from previous installations, with different Owners and Permissions set. /User shows I have three Users set in addition to Guest and Shared. I have used Finder to change permissions for all files to allow me as current User to read/write all. I would like to keep one other user, in addition to Guest and Shared, as admin only to allow access for repair etc.

How can I set myself as Owner of all files with full r/w (and x) access, so I can delete the then-un-needed Users, keeping Shared and Guest?

Answer 1

If I have understood your question properly:

• you have a load of documents
• you would like to ensure that userA is owner of the files
• you would like to ensure that userA has read and write access to the files
• you would also like to have a separate admin account that you use for system changes and not for everyday tasks

Have I got that right? If so,

• Move the documents you would like to keep into /Users/adminA/Public/backup. Use terminal and the mv command: mv /Users/userB/Documents/School /Users/adminA/Public/backup
• Log in as adminA and open terminal
• id userA. In the results you will see gid=XXX (YYY), probably gid=20(staff). Make a note of the YYY
• sudo chown -R userA:YYY “/Users/adminA/Public/backup”. This will change the owner of all the collated files and directories to userA
• sudo find “/Users/adminA/Public/backup” -type f -exec chmod u=rw,g=rw,o= {} \;
• sudo find “/Users/adminA/Public/backup” -type d -exec chmod u=rwx,g=rwx,o= {} \; The last 2 commands give userA read and write access to all of the files, and read/write/execute access over all subdirectories (execute access is needed to search in directories). At this point the group permissions bits are set the same so that we can move the files over from adminA's Documents to userA's Documents directory. You shouldn’t give userA executable access (‘x’) to all of the files because: (I imagine?) most of the files aren’t executable files. Giving files unnecessary executable access is a habit best (and easily) avoided.
• mv /Users/adminA/Public/backup /Users/userA/Documents
• (Now if you want to you could log in as userA, open terminal, and run find “/Users/userA/Documents/backup” -type f -exec chmod u=rw,g=,o= {} \;...
• ... and find “/Users/userA/Documents/backup” -type d -exec chmod u=rwx,g=,o= {} \; to remove group access to the files and subdirectories. This wouldn't really stop the admin account from accessing the files because they can always change permissions but it would stop other user accounts that exist (/will exist) in the staff group.

Answer 2

The pragmatic answer is you can't change in a durable manner the ownership / permissionsof these folders as the system will "fix" them according to it's design any update and any time it writes new files.

Deeper down, some specific applications will refuse to run with overly permissive permissions.

It might be easier to move the files you wish to share openly outside your home folder if you need more than one "local account" to access them. Changes to the permissions in /Users/Shared is more durable than trying to override the design of ~ your home folder - especially for hidden and system like files stores in your user home folder.

Have you explored making a group permission change to allow access? I wonder if a small subset of the files are the only ones you need to "relax" permissions on.

Also, copying the files to an external drive is often very good so you can then ignore the permissions on that drive itself and then copy back the files to a place with default permissions needed.