xref: /openbsd/libexec/fingerd/fingerd.8 (revision 3d8817e4)
1.\"	$OpenBSD: fingerd.8,v 1.18 2007/09/25 06:28:13 jmc Exp $
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30.\"     from: @(#)fingerd.8	8.1 (Berkeley) 6/4/93
31.\"	$Id: fingerd.8,v 1.18 2007/09/25 06:28:13 jmc Exp $
32.\"
33.Dd $Mdocdate: September 25 2007 $
34.Dt FINGERD 8
35.Os
36.Sh NAME
37.Nm fingerd
38.Nd remote user information server
39.Sh SYNOPSIS
40.Nm fingerd
41.Op Fl lMmpSsu
42.Op Fl P Ar filename
43.Sh DESCRIPTION
44.Nm
45implements a simple protocol based on RFC 1288
46that provides an interface to the
47Name and Finger programs at several network sites.
48The program is supposed to return a friendly,
49human-oriented status report on either the system at the moment
50or a particular person in depth.
51There is no required format and the
52protocol consists mostly of specifying a single
53.Dq command line .
54.Pp
55.Nm
56is started by
57.Xr inetd 8 ,
58which listens for
59.Tn TCP
60requests at port 79.
61Once connected it reads a single command line
62terminated by a
63.Aq Tn CRLF
64which is passed to
65.Xr finger 1 .
66.Nm
67closes its connections as soon as the output is finished.
68.Pp
69If the line is null (i.e., just a
70.Aq Tn CRLF
71is sent) then
72.Xr finger 1
73returns a
74.Dq default
75report that lists all people logged into
76the system at that moment.
77.Pp
78If a user name is specified (e.g.,
79.Pf eric Aq Tn CRLF )
80then the
81response lists more extended information for only that particular user,
82whether logged in or not.
83Allowable
84.Dq names
85in the command line include both
86.Dq login names
87and
88.Dq user names .
89If a name is ambiguous, all possible derivations are returned.
90.Pp
91The following options may be passed to
92.Nm
93as server program arguments in
94.Pa /etc/inetd.conf :
95.Bl -tag -width Ds
96.It Fl l
97Enable logging.
98The name of the host originating the query and the actual request
99is reported via
100.Xr syslog 3
101at LOG_NOTICE priority.
102A request of the form
103.Sq /W
104or
105.Sq /w
106will return long output.
107Empty requests will return all currently logged in users.
108All other requests look for specific users.
109See RFC 1288 for details.
110.It Fl M
111Enables matching of
112.Ar user
113names.
114This is disabled by default if the system is running YP.
115.It Fl m
116Prevent matching of
117.Ar user
118names.
119.Ar User
120is usually a login name; however, matching will also be done on the
121users' real names, unless the
122.Fl m
123option is supplied.
124.It Fl P Ar filename
125Use an alternate program as the local information provider.
126The default local program
127executed by
128.Nm
129is
130.Xr finger 1 .
131By specifying a customized local server,
132this option allows a system manager
133to have more control over what information is
134provided to remote sites.
135.It Fl p
136Prevents
137.Xr finger 1
138from displaying the contents of the
139.Dq Pa .plan
140and
141.Dq Pa .project
142files.
143.It Fl S
144Prints user information in short mode, one line per user.
145This overrides the
146.Dq Pa Whois switch
147that may be passed in from the remote client.
148.It Fl s
149Enable secure mode.
150Forwarding of queries to other remote hosts is denied.
151.It Fl u
152Queries without a user name are rejected.
153.El
154.Sh SEE ALSO
155.Xr finger 1 ,
156.Xr inetd 8
157.Sh HISTORY
158The
159.Nm
160command appeared in
161.Bx 4.3 .
162.Sh BUGS
163Connecting directly to the server from a
164.Tn TIP
165or an equally narrow-minded
166.Tn TELNET Ns -protocol
167user program can result
168in meaningless attempts at option negotiation being sent to the
169server, which will foul up the command line interpretation.
170.Nm
171should be taught to filter out
172.Tn IAC Ns 's
173and perhaps even respond
174negatively
175.Pq Tn IAC WON'T
176to all option commands received.
177