gofingerd: simple finger (RFC 1288) daemon in Go
  Copyright (C) 2012 Daniel Verkamp <daniel@drv.nu>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.


USAGE

  gofingerd [-p port] [-i ip/host]

  -p port       listen on specified port number (default: 79)

  -i ip/host    listen on specified IP address or hostname (default: empty,
                meaning listen on all interfaces)

DESCRIPTION

  gofingerd implements the basic components of RFC 1288, with some concessions
  for privacy and security.

  The default response (finger @host) does not include a user listing, but it
  does mention the hostname (based on the -i parameter if specified) and the
  uptime of the system.

  User requests (finger user@host) include only login name, real name (from the
  GECOS field in /etc/passwd), and contents of the user's ~/.plan file, if it is
  readable by the user running gofingerd (generally root, since listening on
  port 79 requires increased privileges).  Users can only be looked up based on
  login name.  Nonexistent users are reported with an error message.

  Verbose requests (finger -l @host and finger -l user@host) are supported, but
  the response is currently the same as the normal response.

  Forwarding requests (finger user@host1@host2@...) are intentionally not
  supported and respond with an appropriate error message.