How to Protect Files on Mac OS X Snow Leopard
Every Mac owner needs to know how to protect files and folders from accidental deletion or editing. Snow Leopard’s Info dialog lets you lock your files to protect them. By locking a file, you allow it to be opened and copied but not changed, renamed, or sent to the Trash. Locked items appear in the Finder with a small padlock attached to the icon.
To lock or unlock a file, you have to have ownership of the file. If you are working on a Mac on which you’ve configured only one administrator account, you should already have ownership.
If you’re considering changing the ownership of a system-owned file, don’t do it. You could throw a serious monkey wrench into your Snow Leopard system.
To lock a file, follow this procedure:
Select the item and then press Command+I (the letter i).
The Info dialog opens.
Select the Locked check box to enable it.
The Locked check box is in the General section of the dialog.
Close the Info dialog.
The changes you made are saved.