| DOMAINNAME(1) | General Commands Manual | DOMAINNAME(1) | 
domainname —
| domainname | [name-of-domain] | 
domainname prints the YP domain name of the current
  host. The super-user can set the domain name by supplying an argument; this is
  usually done in the network initialization script
  /etc/rc.d/network, normally run at boot time.
domainname utility is derived from the
  hostname utility, which appeared in
  4.2BSD. The domainname utility
  appeared in NetBSD 0.8.
| May 31, 1993 | NetBSD 10.0 |