I just installed OS X on this iMac and copied the clients documents from an older machine.
In the home folder, he has many documents owned by nobody:staff. These are not writable.
I tried to change them with sudo chown -R hisname:staff *
but it has not effect. then I find I can't sudo or su
When I installed the operating system I used no passwords,
always reports "Sorry"
How can I change these file permissions?