macOS Sierra: Set permissions for items on your Mac
Permission settings determine who can view and alter files on the computer. You change permission settings at the bottom of the Info window for a file, folder, or disk in the Finder. For example, you can change permission settings for a folder so that other users who log in to your Mac, or connect to it for file sharing, can view but not change files in a folder.
Assign permissions to users and groups
Select a disk, folder, or file, then choose File > Get Info.
If the information in Sharing & Permissions isn’t visible, click the disclosure triangle.
If necessary, click the lock icon to unlock it, then enter an administrator name and password.
Click a user or group in the Name column, then choose a privilege setting from the pop-up menu.
Read & Write: Allows a user to open the item and change it.
Read Only: Allows a user to open the item, but not change its contents.
Write Only: Makes a folder into a drop box. Users can copy items to the drop box, but can’t open it. Only the owner of the drop box can open it.
No Access: Blocks all access to the item.
Apply permissions to all items in a folder or a disk
Change an item’s owner
Select the item, then choose File > Get Info.
Click the lock icon to unlock it, then enter an administrator name and password.
If the new owner’s name isn’t listed in the Name column in the Sharing & Permissions section, click the Add button to add the new owner.
Select the new owner in the Name column, click the Action pop-up menu , then choose “Make __ the owner.”
Add or remove a user or group in the Name column
Select an item, then choose File > Get Info.
If you don’t own the item, click the lock icon to unlock it, then enter an administrator name and password.
In the Sharing & Permissions section, do one of the following:
Add a user or group: Click the Add button below the list, select a user or group, then click Select.
Remove a user or group: Select the user or group, then click the Remove button below the list.
You can undo any changes made in the Sharing & Permissions section of an Info window since opening it, except applying permissions to all the items in a folder or disk.
Make sure the Info window remains open after making your changes.
Click the Action pop-up menu , then choose “Revert changes.”