ypwhich returns the name of the NIS server that supplies the NIS name services to a NIS client, or which is the master for a map. If invoked without arguments, it gives the NIS
server for the local machine. If hostname is specified, that machine is queried to find out which NIS master it is using.
Refer to ypfiles(4) for an overview of the NIS name services.
Find the master NIS server for a map. No hostname can be specified with -m. mname can be a mapname, or a nickname for a map. When mname is omitted, produce a list of available maps.