fingerd - remote user information server
fingerd [-wul] [-pL path]
Fingerd is a simple daemon based on RFC1196 that provides an interface to the ``finger'' program at most network sites. The program is supposed to return a friendly, human-oriented status report on either the system at the moment or a particular person in depth.
If the -w option is given, remote users will get an additional ``Welcome to ...'' banner which also shows some informations (e.g. uptime, operating system name and release) about the system the fingerd is running on. Some sites may consider this a security risk as it gives out information that may be useful to crackers.
If the -u option is given, requests of the form ``finger @host'' are rejected.
If the -l option is given, information about requests made is logged. This option probably violates users' privacy and should not be used on multiuser boxes.
The -p option allows specification of an alternate location for fingerd to find the ``finger'' program. The -L option is equivalent.
Options to fingerd should be specified in /etc/inetd.conf.
The finger protocol consists mostly of specifying command arguments. The inetd(8) ``super-server'' runs fingerd for TCP requests received on port 79. Once connected fingerd reads a single command line terminated by a <CRLF> which is passed to finger(1) . It closes its connections as soon as all output is finished.
If the line is empty (i.e. just a <CRLF> is sent) then finger returns a ``default'' report that lists all people logged into the system at that moment. This feature is blocked by the -u option.
If a user name is specified (e.g. eric<CRLF>) then the response lists more extended information for only that particular user, whether logged in or not. Allowable ``names'' in the command line include both ``login names'' and ``user names''. If a name is ambiguous, all possible derivations are returned.
Connecting directly to the server from a TIP or an equally narrow-minded TELNET-protocol user program can result in meaningless attempts at option negotiation being sent to the server, which will foul up the command line interpretation.
The finger daemon appeared in 4.3BSD.