|whois - An Internet directory service for looking up names of people
on a remote server. Many servers respond to TCP queries on
port 43, in a manner roughly analogous to the DDN NIC
whois service described in RFC 954. Other sites provide
this directory service via the finger protocol or accept
queries by electronic mail for directory information. On
Unix the client command is|
whois -h server_name person_name
You can also type "telnet server_name 43" and then type the person's name on a separate line. For a list of whois servers, FTP/Gopher: sipb.mit.edu. Or
whois -h sipb.mit.edu whois-servers
As the above command demonstrates, whois can find information about things other than users, e.g. domains, networks and hosts.
See also finger, X.500, white pages.