The
ypcat(1),
ypmatch(1), and
ypwhich(1) commands reference NIS (YP) maps as specified by the user. Occasionally it is desirable to use a shorthand reference for a longer map name, hence the
nicknames file, kept in “/var/yp/nicknames.”
The format of the file is
nickname map
one pair per line. The default installed nickname map is as follows:
protocols
protocols.bynumber
master.passwd
master.passwd.byname
A blank or incomplete
nicknames file will affect any scripts which use nicknames for map lookup, whereas if the file is simply missing, the default compiled-in list will be used.