This file documents the GNU Finger program.

   Copyright (C) 1988, 1992 Free Software Foundation, Inc.  Program
authored by Brian Fox, Dante De Lucia, and Jan Brittenson Manual
authored by Brian Fox and Jan Brittenson

   Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.

   Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided also
that the GNU Copyright statement is available to the distributee, and
provided that the entire resulting derived work is distributed under
the terms of a permission notice identical to this one.

   Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions.



   This document describes the GNU Finger program, a utility for
finding out useful information about users on the Internet network.

Introduction
************

   GNU Finger is a utility program designed to allow users of Unix
hosts on the Internet network to get information about each other.  It
is a direct replacement for the Berkeley 4.3 finger code, although it
produces different looking output and is designed to run on a wide
variety of systems.

Why Another Finger?
===================

   Originally, each host on the Internet network consisted of a single,
reasonably powerful computer, capable of handling many users at the same
time.  Typically, a "site" (physical location of computer users) would
have only one or two computers, even if they had 20 or more people who
used them.  If a user at site A wanted to know about users logged on at
site B, a simple program could be invoked to query the host at site B
about the users which were logged on.

   With the onset of more-power-per-person computing, the mainframe has
been set aside.  A modern computing facility usually consists of one
user per host, and many hosts per site.  This makes it a trial to find
out about logged on users at another site, since you must query each
host to find out about the single user who is logged on.  If the site
had 20 hosts, you would have to invoke a finger program 20 times just to
find out who was logged on!

   GNU Finger is a simple and effective way around this problem.  For
sites with many hosts, a single host may be designated as the finger
"server" host.  This host collects information about who is logged on
to other hosts at that site.  If a user at site A wants to know about
users logged on at site B, only the server host need be queried,
instead of each host at that site.  This is very convenient.

   GNU Finger is a direct replacement for existing finger programs.
Since the finger "protocol" (rules for communication) is very simple,
GNU Finger follows that protocol in responding to simple requests.  But
GNU Finger also implements another protocol which allows two finger
programs to exchange information in a predetermined way, which allows
faster and wider bandwidth communication.

   Finger delivers information about users in varying formats,
depending on how it is invoked.  `finger' invoked without any options
performs a *site wide* finger request, no matter which machine it has
been invoked from.  Switch arguments exist for getting the "long" form
of finger information and for getting information only about the local
machine.

   If a user on host A wants to know about a user on host B, finger must
make a network "connection" to host B.  If host B is running a finger
program, that program is asked to relay information about the user in
question through the connection back to host A, where finger can
display it.

   GNU Finger also runs a server "daemon" process on the "server" host,
whose job is to keep track of which users are logged in to local
machines.

   An optional and currently unsupported feature is passing of graphic
images. This is built on the new protocol.  A user at site A (e.g. MIT)
may see the picture of a user at site B (e.g. UCSB), by typing a finger
request.  The conversion of graphic data from one format to another is
done through GNU Finger; no site need know where or how such images are
stored on any other site to be able to display those images. You should
ask your system administrator to find out whether he has chose to
include this functionality on your network.

Using Finger
************

Arguments to GNU Finger
=======================

   The basic argument to Finger is a USER@HOST pair.  The USER portion
is the name of the user about whom you would like information.  The
HOST is a machine that the user has an account on.   When invoked in
this manner, GNU Finger displays the list of hosts that this user is
currently logged in on, or, if the user is not logged in, the last time
and location that he or she was.  HOST may be expressed as any valid
Internet address (i.e.  "dot-notation", "host.domain", etc).

   If HOST is non-existent, the local host is assumed.  If USER is
blank or unspecified, it is assumed that you want information about all
users.

   The content and format of the output of GNU `finger' depends on what
is being fingered:

USER
     Displays login information about USER. If `--info' or `--l' is
     also specified, `finger' will display the full name, home
     directory, shell, mail forwarding, and `.plan' and/or `.project'
     file. This is what the output will look like:

     `bash$ finger --info bson@gnu.ai.mit.edu'
     `[apple-gunkies.gnu.ai.mit.edu]'

     `Jan Brittenson (bson)'
     `Home: /home/fsf/bson'
     `Shell: /usr/local/bin/bash'
     `Mail forwarded to bson@ai.mit.edu.'
     `No mail.'
     `  User     Real Name         What    Idle  TTY  Host      Console Location'
     `bson     Jan Brittenson     fgrep          *p0 apple-gu (nutrimat.gnu.ai.)'
     `bson     Jan Brittenson              1:57  *sb nutrimat '

     `Plan:'
     `	To hack GNU Finger'

     The following is output, in the order listed, when asking for long
     information (`-l' or `--info') about a particular user:

        * Real and login names.

        * Home directory.

        * Login shell.

        * Mail forwarding.

        * Whether the user has any unread mail, and if so, when it was
          last read.

        * Current login information, in the same format as produced by
          a short finger (see below for an explanation). If the user
          isn't currently logged on, then the last login time and
          remote host (if known) is reported.

        * A `~/.plan' file. If the file isn't readable by everyone,
          then a message is printed to this effect.

        * A `~/.projects' file. This file, like `~/.plan', should be
          readable by everyone.


     `bash$ finger bson@gnu.ai.mit.edu'
     `[apple-gunkies.gnu.ai.mit.edu]'
     `  User     Real Name         What    Idle  TTY  Host      Console Location'
     `bson     Jan Brittenson     fgrep          *p0 apple-gu (nutrimat.gnu.ai.)'
     `bson     Jan Brittenson              1:57  *sb nutrimat '

     Here is an explanation of what each column contains in the short
     example:

    `User'
          The user login name.

    `Real Name'
          The real name of the user.

    `What'
          The current or last program run by the user, depending on the
          system in use. On System V Release 4, for instance, the
          current program is shown, but on BSD it will be the last
          terminated program.

    `Idle'
          The time the user has been idle, as HOURS:MINUTES, or the
          first 7 characters of a string such as "14 days".

    `TTY'
          The significant portion of the user's terminal connection.
          Exactly what portion this is is system dependent. For
          example, on System V Release 4, it might be `*40' for
          `/dev/pty/40', while on BSD it might be `*p0' for
          `/dev/ttyp0'. If preceded by an asterisk ("*"), then the user
          allows anyone to send messages to this particular terminal.

    `Host'
          The host the user is logged onto.

    `Console Location'
          Where the user's console is located. If logged in over the
          network, then this will be the most significant portion of
          the remote host name if known. A host name is always
          parenthesized.

     In the general short output (i.e. not for a particular host), GNU
     Finger lists the least idle login for a particular user on each
     host. A single user often has several logins, since on some
     systems each window opened creates its own login record. In
     addition to the least idle login, the console login is also always
     listed, regardless of how long it has been idle.

     To list "all" login records for a particular, host, use the special
     target `.local'. For example, while the following may be part of
     the general short finger listing for the host
     `mole.gnu.ai.mit.edu':

     `brendan  Brendan Kehoe               5:09  *p8 mole     (lisa.cygnus.com)'
     `info     InfoMaster                 12:12  *p4 mole     (hal)'
     `law      Jeffrey A. Law              3:52  *p7 mole     (128.110.4.17:0.0)'
     `rms      Richard Stallman   sendmai  1:34  *p1 mole     (unix:0.0)'
     `rms      Richard Stallman           6 days *co mole'

     The last line is the console. The following might be listed by the
     command `finger .local@mole.gnu.ai.mit.edu':

     `[mole.gnu.ai.mit.edu]'
     `  User     Real Name         What    Idle  TTY  Host      Console Location'
     `brendan  Brendan Kehoe               5:18  *p8 mole     (lisa.cygnus.com)'
     `info     InfoMaster                 12:22  *p4 mole     (hal)'
     `law      Jeffrey A. Law              4:01  *p7 mole     (128.110.4.17:0.0)'
     `rms      Richard Stallman   sendmai  1:44  *p1 mole     (unix:0.0)'
     `rms      Richard Stallman           23:08  *p0 mole     (unix:0.0)'
     `rms      Richard Stallman           1 day, *p2 mole     (unix:0.0)'
     `rms      Richard Stallman           6 days *co mole'

MAILING LIST OR ALIAS
     Expands the mailing list or alias and displays the recipients. You
     always have to use `--info' or (or `-l') when fingering a mailing
     list or mail alias, otherwise mail aliases won't be looked up due
     to the extra processing involved. This is what the output will look
     like:

          % finger --info postmaster@gnu.ai.mit.edu
          postmaster is an alias for the following:
              Roland McGrath <roland>,
              <tower@prep.ai.mit.edu>,
              Noah Friedman <friedman>,
              Michael I Bushnell <mib>

USER-DEFINED TARGET
     Allows the remote host to display specific information, such as
     price lists, literature, or weather forecasts. For example:

          % finger .site@gnu.ai.mit.edu
          
          This is the FSF GNU Project. For more information, please contact
          "postmaster". For information about guest accounts, please contact
          "request".

Command Line Options
====================

   There are a number of command line options that you can give to GNU
Finger:

`--face'
`-f'
     Ask Finger for the face of all users information has been requested
     about. An explicit user list has to be provided.

`--info'
`-l'
`-i'
     Display the "long" form of information for the users fingered. The
     exact information returned depends on what finger software is run
     on the remote host - GNU Finger, for instance, returns specific
     information.  `-l' is supplied for backwards compatibility;
     `finger' as distributed from Berkeley has this option.

`--brief'
`-b'
     Display the "short" form of information for the users fingered.
     This is the opposite of `--info'.

`--port PORT'
`-P PORT'
     Make a connection to PORT, which can be either a numerical port
     number or a service name from `/etc/services'.

`--help'
`-h'
     Print a description of all options.

Special User Names
==================

   You can give GNU Finger one of several "special" user names.  These
user names all begin with a period (`.') and instruct the receiving
finger daemon to do something that only a GNU Finger daemon can do.
Currently, the "special" names are:

`.free'
     Return a list of free machines.  `Free' machines are those that
     have no users logged in, or have been idle for a long time.  The
     information returned makes it clear which one is true.

`.all'
     Return the information about every machine that the Finger server
     knows about.  `.all' is equivalent to issuing the `finger' command
     without specifying the user name.

`.site'
     Returns information about the site, such as company and location.

`.clients'
     Returns a list of the clients that the GNU Finger server knows
     about.  Also lists who is logged onto the console.

`.faces'
     Return a list of the faces that this server has available.  The
     last line output tells you how many lines were listed previously.

`.local'
     Finger only at the specific machine. This allows finger to
     continue to be useful even in the event that the server is down.
     It also allows you to examine "all" the login records of a user.
     Normally, the server only keeps track of the most recently active
     login record for each user.

`.help'
     Describe services provided by the finger server.

Advanced Use
************

How Finger Works
================

   GNU Finger is the collective name for a set of programs:
`finger'
     Parses the command line and connects to the finger server,
     `in.fingerd', on the `finger' server. Returns the output from the
     server. `finger' connects to `in.fingerd' on the host specified in
     the command line. This is the only program you need to know
     anything about if you're a regular user. You should refer to this
     program as the "finger client" to avoid possible confusion.

`fingerd'
     Regularly connects to `in.cfingerd' on the clients specified in the
     `fingerdir/clients' file, to obtain finger data. This client data
     is saved in the file `fingerdir/userdata'. `fingerd' should run on
     the host specified in the `fingerdir/serverhost' file.  `fingerd'
     should be started at boot time.

`in.fingerd'
     Responds to `finger' connections through `inetd'. Should be
     attached to the `finger' service via `/etc/inetd.conf'.
     `in.fingerd' behaves somewhat differently depending on what host it
     runs on: on the server host it reads the `fingerdir/userdata'
     database, on all other hosts it forwards all requests (unless
     `.local' is the target) to `in.fingerd' on the host specified in
     `fingerdir/serverhost'.

     `in.fingerd' reads the `fingerdir/userdata' database, various
     system files, and makes SMTP connections to the host specified in
     the `fingerdir/mailhost' file.

`in.cfingerd'
     This is the program that responds to call-ins from `fingerd' by
     sampling the status on the client and forwarding it to `fingerd'.
     It should be configured to respond to the `cfinger' service
     specified in the `clients' configuration file, or port 2003 if
     nothing else is specified.

The `~/.fingerrc' Script
========================

   When the GNU Finger server receives a request for information about a
user it looks to see if the user has a `.fingerrc' file in the home
directory. If such a file exists, and is executable, then this file is
executed, and the normal finger output is passed to it as input.  Its
output becomes what is returned for the request. Thus, it can be used
to:

   * Disable fingering a specific user by linking `~USER/.fingerrc' to
     `/bin/true'.

   * Entirely replace the output of `finger' by ignoring its input.
     Below is a sample script which could be put in
     `~price-info/.fingerrc'.

          #! /bin/sh
          #
          # This sample script replaces the output of GNU Finger
          #
          echo Hack-O-Matic Consulting Services, Inc. "   " `date`
          
          cat <<ETX
          
          Hi, thanks for asking us about prices on our newly introduced support
          services for Free Software. Below is a list of new services; for a list
          of our previous services, please send mail to this address and someone
          will contact you. Please don't forget to tell us how to reach you.
          
          ETX
          cat ~/info/new-stuff

   * Filter the output to make changes. If the script below is put in
     `~bson/.fingerrc' on the finger server host for the domain
     `gnu.ai.mit.edu':

          #! /bin/sh
          #
          # This sample filter replaces the "Project:" tag with
          # "Working on:"
          #
          sed -e 's/^Project:$/Working on:/g'

     Then when `finger -l bson@gnu.ai.mit.edu' is run, the output could
     look something like:

          Jan Brittenson (bson)
          Home: /home/fsf/bson
          Shell: /usr/local/bin/bash
          No mail.
          
          Jan Brittenson (bson) is not presently logged in.
          Last seen at wombat.gnu.ai.mit.edu on Tue Sep  1 15:08:12 1992
          
          No plan.
          
          Working on:
                  1. Hacking GNU Finger
                  2. Making friends

User-defined Targets
====================

   Various special targets can be added as executable files in the
directory `fingerdir/targets'. Each file name in this directory starts
with a letter describing when to execute it, followed by a hyphen and
the target name. The three letters are:

`l'
     In response to a "long" finger; usually by typing `finger -l'.

`s'
     In response to a "short" finger; usually the default if no options
     are given.

`x'
     In response to either a "long" or "short" request.

   For instance, the special-target file `x-.help' is run for either
`finger .help' or `finger -l .help', whereas the special- target file
`l-prices' is run only for `finger -l prices'.

   The special-target file is run as super-user, and is given no input.
By convention, all GNU Finger sites should support at least:

`.help'
     Display message describing what features and special targets exist
     on this site.

`.site'
     Display message describing the site. This may include such things
     as the company name, its address, and how to contact the system
     manager.

How Finger Picks a Port
=======================

   When invoked, the GNU Finger client looks to see if a `--port'
option was specified on the command line. If so, then this becomes the
port number or service used. Otherwise, the client looks to see what
name it was started under, removes any leading directory path, and any
trailing suffixes. A suffix is the part of a filename that follows a
dot, including the dot itself. This is the service name used.  For
instance, if GNU Finger is installed as `/usr/local/bin/finger.new',
then the service `finger' is used. If it's installed as
`/usr/local/bin/gfinger', then the service `gfinger' is used. This
behavior can be changed by the system administrator during installation.

Security Issues
***************

   One question that often arises when installing networking software
which adds new functionality is whether it can be considered
sufficiently secure. The most significant new function in GNU Finger
with regard to security is the ability for a user to have a `.fingerrc'
in the home directory. The following are the precautions take by GNU
Finger:

   * Check whether `.fingerrc' is writable to anyone except the owner.
     Notice that check is not enabled by default, since FSF users like
     anyone to be able to write any file - enable this check during
     installation by editing `config.h'.

   * Check whether `.fingerrc' is owned by the user in whose home
     directory it's found. This, like the previous check, is disabled by
     default. It really only makes sense on systems where ordinary users
     can't give away their files.

   * Execute the script through the user's login shell, using the
     command "SHELL -c SCRIPT". This means that a user who has had his
     account disabled (i.e. shell set to a program that prints a notice
     or just dies) can't run a `.fingerrc' script. This behavior can be
     changed by hard-coding the shell in `config.h'.

Bug Reports
***********

   You are strongly encouraged to submit a bug report to
bug-gnu-utils@gnu.ai.mit.edu if you have problems with this beta
release of GNU Finger. Here are some things that are generally helpful
to mention, when relevant:

   * The GNU Finger version and where you obtained the distribution.

   * Your hardware.

   * Operating system.

   * C Compiler used.

   * The arguments you gave to `./configure'.

   * Changes you made to the GNU Finger configuration files.

   * Any changes you have made to the source code or installation
     procedures.

   * Your network configuration; don't forget to mention what hardware,
     operating systems, and C compilers are used on each node where the
     bug manifests itself.

   * Any problems you had during installation.

   If you're having problems compiling or installing GNU Finger, then
the following is particularly helpful to mention:

   * The command line used to invoke `configure'.

   * The current directory.

   * The command line used to invoke `make' and `make' version
     (particularly if you're using GNU Make).

   * A capture of the compiler output.

   Please feel free to include any patches, as well.

Installation
************

Basic Installation
==================

   Here are the steps that you will need to take in order to install
GNU Finger.

  1. Pick a machine which will be the local finger server for your
     network.  Create a `clients' file, and install it in
     `/usr/local/etc/fingerdir' (or the EtcDir as specified in
     `config.h'). Put the names of all hosts that should report to the
     finger server in this file. Don't forget to include the finger
     server itself.

  2. For each client (the designated server is also a client), do the
     following,

  3. Change your working directory to be the top of the GNU Finger
     sources.  For instance, if you have placed the source in
     `/src/gnu/finger' you would type `cd /src/gnu/finger'.

  4. In the source directory, type `make clean' and `./configure' if
     this host is different from the previous one.  If you're using
     `csh' on an old version of System V, you might need to type `sh
     ./configure' instead to prevent `csh' from trying to execute
     `configure' itself.

     The `configure' shell script attempts to guess correct values for
     various system-dependent variables used during compilation, and
     creates the Makefile(s) (one in each subdirectory of the source
     directory).  In some packages it creates a C header file containing
     system-dependent definitions.  It also creates a file
     `config.status' that you can run in the future to recreate the
     current configuration.

     Running `configure' takes a minute or two.  While it is running, it
     prints some messages that tell what it is doing.  If you don't
     want to see the messages, run `configure' with its standard output
     redirected to `/dev/null'; for example, `./configure >/dev/null'.

     To compile the package in a different directory from the one
     containing the source code, you must use a version of make that
     supports the VPATH variable, such as GNU make.  `cd' to the
     directory where you want the object files and executables to go
     and run `configure'.  `configure' automatically checks for the
     source code in the directory that `configure' is in and in `..'.
     If for some reason `configure' is not in the source code directory
     that you are configuring, then it will report that it can't find
     the source code.  In that case, run `configure' with the option
     `--srcdir=DIR', where DIR is the directory that contains the
     source code.

     You can tell `configure' to figure out the configuration for your
     system, and record it in `config.status', without actually
     configuring the package (creating `Makefile' and perhaps a
     configuration header file).  To do this, give `configure' the
     `--no-create' option.  Later, you can run `./config.status' to
     actually configure the package for a particular host.  This option
     is useful mainly in `Makefile' rules for updating `config.status'
     and `Makefile'.  You can also give `config.status' the `--recheck'
     option, which makes it re-run `configure' with the same arguments
     you used before.  This is useful if you change `configure'.

     `configure' ignores any other arguments that you give it.

     If you want to install the GNU Finger configuration files somewhere
     other than `/usr/local/etc/fingerdir', then you should edit the
     files `./config.h' and `include/fingerpaths.h' now.  You need to
     specify the alternate locations of where the configuration files
     will be kept. If you want to include the unsupported code for
     mugshots, then you should now also choose one of the face formats,
     as well as edit `lib/Makefile.in', `lib/site/Makefile.in', and
     `src/Makefile.in' to compile and link in the files necessary.

     If your system requires unusual options for compilation or linking
     that `configure' doesn't know about, you can give `configure'
     initial values for some variables by setting them in the
     environment.  In Bourne-compatible shells, you can do that on the
     command line like this:

          CC='gcc -traditional' DEFS=-D_POSIX_SOURCE ./configure

     The `make' variables that you might want to override with
     environment variables when running `configure' are:

     (For these variables, any value given in the environment overrides
     the value that `configure' would choose:)

    `CC'
          C compiler program. Default is `cc', or `gcc' if `gcc' is in
          your search path.

    `INSTALL'
          Program to use to install files. Default is `install' if you
          have it, `cp' otherwise.

     (For these variables, any value given in the environment is added
     to the value that `configure' chooses:)

    `DEFS'
          Configuration options, in the form `-Dfoo -Dbar ...'

    `LIBS'
          Libraries to link with, in the form `-lfoo -lbar ...'

  5. To build and/or install the GNU Finger executables and standard
     targets, issue one of the following commands:

    `make server'
          To build and install all executables, plus install the
          finger-specific server configuration files. Use this if the
          host is the designated finger server.

    `make client'
          To build all executables, but install only those used by the
          non-server clients. Use this unless the host is the
          designated finger server.

    `make all'
          To build all executables, but perform no installation.

     The above commands build `lib/libfinger.a' and the main programs in
     `src': `finger', `in.fingerd', and `in.cfingerd', as well as
     `fingerd' on the server.  If you want to, you can override the
     `make' variables `CFLAGS' and `LDFLAGS' like this:

          make CFLAGS=-O2 LDFLAGS=-s

  6. Modify the system configuration so that the client has (refer to
     the system documentation for details on how to do this on a
     particular system):

        * Entries in the system `services' file, or equivalent, which
          mentions the correct TCP port for `in.cfingerd' (port 2003)
          and `in.fingerd' (port 79). If port 2003 is already used by
          something else, then read the section on Configuration Files
          for details on how to specify a port other than 2003 in the
          `/usr/local/etc/fingerdir/clients' file. A good name for the
          service is `cfinger'.

        * Entries in the system `inetd.conf' file, or equivalent, which
          contains references to `in.cfingerd' and `in.fingerd'.
          `in.fingerd' needs to be run with UID `root'.  Consult your
          system documentation for details on how to do this.
          `in.cfingerd' should be run with UID `root' on System V
          derivatives.

        * a `/usr/local/etc/fingerdir/serverhost' file which contains
          the name of the GNU Finger server host,

        * a `/usr/local/etc/fingerdir/mailhost' file which contains the
          name of the mail server to ask for user mail forwarding
          information and mailing list expansion, and

        * the inetd daemon restarted, so that server and user requests
          can be answered.

  7. When you have performed the above steps for each client, log onto
     the designated GNU Finger server.

  8. Start the server daemon, `fingerd'. You should arrange to have
     `fingerd' started every time the server host is rebooted. For exact
     details on how to do this, please refer to the server host's system
     documentation.

  9. If you chose to include the mugshots option, now might be a good
     time to install the mugshots.  But first, try getting a face from
     another site running GNU Finger!  For example, you might try
          `finger --face bfox@aurel.cns.caltech.edu'

 10. Modify the files `x-.help' and `x-.site' in
     `/usr/local/etc/fingerdir/targets' for your site.


   Now you're all set! You might like to read through the section on
Configuration Files.

Configuration Files
===================

   This section describes the format of the GNU Finger configuration
files.

The `clients' file
------------------

   The `/usr/local/etc/fingerdir/clients' file contains a list of
clients that the GNU Finger server `fingerd' is supposed to poll.  You
can edit this file and then send the finger server a `SIGHUP' to tell
it that the configuration has changed. Each line in the file should be
either the name of a host or a comment. The name can be preceded by
`@PORT', to tell the finger server to poll the particular host by using
a port other than 2003. A comment is any line that starts with a hash
sign (#). Below is a sample `clients' file:

     # This file contains all GNU Finger clients on the gnu.ai.mit.edu
     # network. Apple-gunkies is the GNU Finger server (see ``serverhost'').
     apple-gunkies.gnu.ai.mit.edu
     
     # Albert is the mail exchanger (see ``mailhost'').
     albert.gnu.ai.mit.edu
     
     # Spiff is a Sony, so port 2003 is already used for `mbanks'.
     # Use port 2010 instead.
     @2010 spiff.gnu.ai.mit.edu
     
     churchy.gnu.ai.mit.edu
     mole.gnu.ai.mit.edu
     geech.gnu.ai.mit.edu
     wookumz.gnu.ai.mit.edu
     nutrimat.gnu.ai.mit.edu
     kropotkin.gnu.ai.mit.edu
     goldman.gnu.ai.mit.edu
     hal.gnu.ai.mit.edu
     wombat.gnu.ai.mit.edu

   Although this sample `clients' file contains the fully qualified
domain names of the hosts, it's usually enough to specify only the host
name portion. Explicit IP addresses can be used too, but this is a
practise strongly discouraged. Notice that the server is also in the
clients file and has a `in.cfingerd'; this is necessary in order for
the server to correctly poll itself.

The `serverhost' file
---------------------

   The `/usr/local/etc/fingerdir/serverhost' file holds the name of the
GNU Finger server host; this is as the name implies, the host that the
GNU Finger server `fingerd' runs on. Lines starting with a hash sign
(#) are treated as comments. Below is a sample `serverhost' file:

     # A-g does all the finger stuff
     apple-gunkies.gnu.ai.mit.edu

The `mailhost' file
-------------------

   The `/usr/local/etc/fingerdir/mailhost' file holds the name of the
mail exchanger host for the network. This host should know how to talk
SMTP; this file should never hold the name of a host that can't. It's
contacted to obtain mail forwarding information and to expand mailing
lists if a `.forward' file can't be found in the user's home directory.
GNU Finger always looks and reports on user `.forward' files regardless
of whether `mailhost' exists or not. Any lines in this file that start
with a hash sign (#) are treated as comments.

The `forwardhost' file
----------------------

   The `/usr/local/etc/fingerdir/forwardhost' file holds the name of
the host to forward finger requests to when the current finger server
can't find a matching user name or mail alias. No forwarding takes place
if this file doesn't exist. Any lines that start with a hash sign (#)
are treated as comments. This is a sample output of what it can look
like when a request is forwarded:

     % finger -l nosuchuser@gnu.ai.mit.edu
     [No user nosuchuser@apple-gunkies.gnu.ai.mit.edu, forwarding
      request to life.ai.mit.edu]
     Login name: nosuchuser			In real life: ???

The `ttylocs' file
------------------

   The `/usr/local/etc/fingerdir/ttylocs' file holds explanations for
the hosts or terminal lines that users have logged in from or through.
Each client host has its own copy of this file. Each line consists of a
host name followed by a description. The name and description are
separated by one or more blanks or TABs.

     spiff.gnu.ai.mit.edu            NE43 Hall
     susie.gnu.ai.mit.edu            NE43 Sony 427 x8568
     spike.gnu.ai.mit.edu            NE43 Sony 427 x8568
     apple-gunkies.gnu.ai.mit.edu    NE43 427
     sugar-bombs.gnu.ai.mit.edu      Elsewhere
     pogo.gnu.ai.mit.edu             NE43 447
     albert.gnu.ai.mit.edu           Noisy Machine Room
     128.52.46.42                    The salt mines
     churchy.gnu.ai.mit.edu          NE43 426
     mole.gnu.ai.mit.edu             NE43 430
     geech.gnu.ai.mit.edu            NE43 426
     wookumz.gnu.ai.mit.edu          NE43 427
     calvin.gnu.ai.mit.edu           NE43
     gnu.gnu.ai.mit.edu              NE43
     kropotkin.gnu.ai.mit.edu        Total anarchy

Site Specific Functions
=======================

   If you are interested in customizing GNU Finger's output, then the
`lib/site' directory is the right place to start.  If you would like to
add new code for displaying faces, or have a particularly interesting
"long" information output format, I would be glad to include it as
unsupported code in the next release of GNU Finger.  (I will direct
correspondence regarding your code to you.) You can find other
contributed code in `lib/site', most notably different user info
formats and code to handle different bit map file formats. The only
file supported in `lib/site' is `userinfo.c'.

Configuration Options
=====================

   The following definitions in `config.h' control the behavior of GNU
Finger:

`SUPPORT_FINGERRC'
     Undefine to prevent users from writing `.fingerrc' scripts. Defined
     by default.

`CHECK_OWNER_FINGERRC'
     Define to make sure `.fingerrc' is owned by the user in whose
     directory it's found.

`CHECK_RDONLY_FINGERRC'
     Define to make sure `.fingerrc' isn't writable by anyone other than
     its owner.

`FINGERRC_SHELL'
     The shell to use to execute `.fingerrc'. Undefine to use user's
     login shell.

`DEFAULT_POLL_INTERVAL'
     Define to be the delay between polls, in seconds, unless an
     interval is explicitly given to `fingerd' with the `--interval'
     option.

`BASENAME_IS_SERVICE'
     Undefine if you always want the finger client to use the `finger'
     service. Otherwise the service is deduced from the basename of the
     client. Defined by default.

`INFO_IS_DEFAULT'
     Define if you prefer `finger --info' to be the default, undefine if
     you prefer `finger --brief' to be the default.

GNU Finger Quick Reference
**************************

     finger OPTIONS USER@HOST

   Finger obtains information about USER on the remote system HOST. It
can also be used to obtain information about mailing lists and special
site-specific services.

   OPTIONS can be one or more of:

`--info'
`-i'
`-l'
     Return as much information as possible about USER.

`--brief'
`-b'
`-s'
     Only display current login info.

`--face'
`-f'
     Display a mugshot of USER. Not supported.

`--port PORT#'
`-P PORT#'
     Connect to the finger server using port or service PORT#.