The getdomainname function returns the standard NIS domain name for the current host, as previously set by setdomainname. The namelen argument specifies the size of the name array. The returned name is null-terminated unless insufficient space is provided.
The setdomainname function sets the NIS domain name of the host machine to be name, which has length namelen. This call is restricted to the super-user and is normally used only when the system is bootstrapped.
The following errors may be returned by these calls: