pwd

[David Barts]

As numerous responses have told me, the system does not maintain
an open file descriptor into the current working directory.  Rather,
pwd works its way back up the tree by finding the i number of .
and searching for the entry under .. whose i-number matches that
of dot.  Special trickery is needed to handle mount points.

/bin/pwd is setuid to root so it can handle unreadable directories
in the path.
-- 
David Barts			Pacer Corporation
davidb at pacer.uucp		...!fluke!pacer!davidb