domainname(1yp)
NAME
domainname − display or set the name of the current domain for this system
SYNTAX
domainname [nameofdomain]
DESCRIPTION
The domainname command, when used without an argument, displays the name of the current domain. The /etc/rc.local startup script must be used to set the current domain name before any other YP commands can be issued.
A domain is a logical grouping of networked-connected systems established for the purpose of sharing a common set of data files. Domains are only used by the yellow pages (YP) service and are called YP domains. A YP domain is a directory in /etc/yp, established through the use of the domainname command, where a YP server holds all of the YP maps. Each YP map contains a set of keys and associated key values. For example, in a map called hosts.byname, the host names stored there constitute the keys. The corresponding internet addresses of each host constitute the associated key values.