Get or set a unique 32-bit identifier for the current machine. The 32-bit
identifier is intended to be unique among all UNIX systems in
existence. This normally resembles the Internet address for the local
machine, as returned by
gethostbyname(3),
and thus usually never needs to be set.
The
sethostid() call is restricted to the superuser.
The
hostid argument is stored in the file
/etc/hostid.