if a user needs to change the permissions of a file to read only for all users, what is the recommended
Use the Terminal to adjust file permissions with command line tools.
Use Repair Permissions in the Disk Utility to adjust the file’s permissions.
Use the Sharing & Permissions pop-up menu in the file’s Get Info window to choose read only for all
Place the file into a folder, then change folder permissions to read only using the Sharing &
Permissions pop-up menu in the folder’s Get Info window.