NAME

    AnyEvent::Finger - Simple asynchronous finger client and server

VERSION

    version 0.14

SYNOPSIS

    client:

     use AnyEvent::Finger qw( finger_client );
     
     finger_client 'localhost', 'username', sub {
       my($lines) = @_;
       print "[response]\n";
       print join "\n", @$lines;
     };

    server:

     use AnyEvent::Finger qw( finger_server );
     
     my %users = (
       grimlock => 'ME GRIMLOCK HAVE ACCOUNT ON THIS MACHINE',
       optimus  => 'Freedom is the right of all sentient beings.',
     );
     
     finger_server sub {
       my $tx = shift; # isa AnyEvent::Finger::Transaction
       if($tx->req->listing_request)
       {
         # respond if remote requests list of users
         $tx->res->say('users: ', keys %users);
       }
       else
       {
         # respond if user exists
         if(defined $users{$tx->req->username})
         {
           $tx->res->say($users{$request});
         }
         # respond if user does not exist
         else
         {
           $tx->res->say('no such user');
         }
       }
       # required! done generating the reply,
       # close the connection with the client.
       $tx->res->done;
     };

DESCRIPTION

    This distribution provides an asynchronous finger server and client
    which can be used by any event loop supported by AnyEvent. This
    specific module provides a simple procedural interface to client and
    server classes also in this distribution.

FUNCTIONS

 finger_client

     finger_client( $server, $request, $callback, [ \%options ] )

    Send a finger request to the given server. The callback will be called
    when the response is complete. The options hash may be passed in as the
    optional forth argument to override any default options (See
    AnyEvent::Finger::Client for details).

 finger_server

     my $server = finger_server $callback, \%options;

    Start listening to finger callbacks and call the given callback for
    each request. See AnyEvent::Finger::Server for details on the options
    and the callback.

CAVEATS

    Finger is an oldish protocol and almost nobody uses it anymore.

    Most finger clients do not have a way to configure an alternate port.
    Binding to the default port 79 on Unix usually requires root. Running
    AnyEvent::Finger::Server as root is not recommended.

    Under Linux you can use iptables to forward requests to port 79 to an
    unprivileged port. I was able to use this incantation to forward port
    79 to port 8079:

     # iptables -t nat -A PREROUTING -p tcp --dport 79 -j REDIRECT --to-port 8079
     # iptables -t nat -I OUTPUT -p tcp -d 127.0.0.1 --dport 79 -j REDIRECT --to-port 8079

    The first rule is sufficient for external clients, the second rule was
    required for clients connecting via the loopback interface (localhost).

SEE ALSO

      * RFC1288 <http://tools.ietf.org/html/rfc1288>,

      * AnyEvent::Finger::Client,

      * AnyEvent::Finger::Server

      * AnyEvent

      Generic non-blocking event loop used by AnyEvent::Finger

      * Net::Finger

      Blocking implementation of a finger client

      * Net::Finger::Server

      Blocking implementation of a finger server

      * PlugAuth::Plugin::Finger

      PlugAuth plugin that allows querying a PlugAuth server via the finger
      protocol. Uses this module for its implementation.

AUTHOR

    Graham Ollis <plicease@cpan.org>

COPYRIGHT AND LICENSE

    This software is copyright (c) 2012-2022 by Graham Ollis.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.