current hostname as returned by the gethostname (3) system call. If no static hostname ... hostname change notifications are not necessary. Use gethostname (2), /etc/hostname (poss…determined from the local hostname returned by gethostname (2); the local domain name is takendetermined from the local hostname returned by gethostname (2); the local domain name is takenlocally set hostname as returned by gethostname (2), or a machine ID formatted as string