Many Mac users are unaware that copying a file or folder in the Finder, or moving it to another location, does not preserve the permissions and ownership data attached to it.
In most circumstances, that's not a problem as you’ll be moving stuff within your own user account. Hence, the default behavior of changing ownership/permissions is actually desirable for most users, in most cases.
But on occasion, you may need to override the default setting when, say, copying a file into another user’s folder, dropping a document into the Guest account and so forth. In these kinds of scenarios, preserving the original file’s ownership and permissions can save you headache down the road.
But worry not — the Mac's Finder includes a pair of hidden features, Paste Item Exactly and Duplicate Exactly, that get the job done. The following tips will teach you how to leverage them to ensure that the file’s ownership information and permission data has been kept intact after the copy/move operation.