Ubuntu Manpage: Net::IRC - Perl interface to the Internet Relay Chat protocol

NAME

       Net::IRC - Perl interface to the Internet Relay Chat protocol

SYNOPSIS

           use Net::IRC;

           $irc = new Net::IRC;
           $conn = $irc->newconn(Nick    => 'some_nick',
                                 Server  => 'some.irc.server.com',
                                 Port    =>  6667,
                                 Ircname => 'Some witty comment.');
           $irc->start;

DESCRIPTION

Welcome to Net::IRC, a work in progress. First intended to be a quick tool for writing an
IRC script in Perl, Net::IRC has grown into a comprehensive Perl implementation of the IRC
protocol (RFC 1459), developed by several members of the EFnet IRC channel #perl, and
maintained in channel #net-irc.

There are 4 component modules which make up Net::IRC:

• Net::IRC

The wrapper for everything else, containing methods to generate Connection objects
(see below) and a connection manager which does an event loop on all available
filehandles. Sockets or files which are readable (or writable, or whatever you want it
to select() for) get passed to user-supplied handler subroutines in other packages or
in user code.

• Net::IRC::Connection

The big time sink on this project. Each Connection instance is a single connection to
an IRC server. The module itself contains methods for every single IRC command
available to users (Net::IRC isn't designed for writing servers, for obvious reasons),
methods to set, retrieve, and call handler functions which the user can set (more on
this later), and too many cute comments. Hey, what can I say, we were bored.

• Net::IRC::Event

Kind of a struct-like object for storing info about things that the IRC server tells
you (server responses, channel talk, joins and parts, et cetera). It records who
initiated the event, who it affects, the event type, and any other arguments provided
for that event. Incidentally, the only argument passed to a handler function.

• Net::IRC::DCC

The analogous object to Connection.pm for connecting, sending and retrieving with the
DCC protocol. Instances of DCC.pm are invoked from "Connection->new_{send,get,chat}"
in the same way that "IRC->newconn" invokes "Connection->new". This will make more
sense later, we promise.

The central concept that Net::IRC is built around is that of handlers (or hooks, or
callbacks, or whatever the heck you feel like calling them). We tried to make it a
completely event-driven model, a la Tk -- for every conceivable type of event that your
client might see on IRC, you can give your program a custom subroutine to call. But wait,
there's more! There are 3 levels of handler precedence:

• Default handlers

Considering that they're hardwired into Net::IRC, these won't do much more than the
bare minimum needed to keep the client listening on the server, with an option to
print (nicely formatted, of course) what it hears to whatever filehandles you specify
(STDOUT by default). These get called only when the user hasn't defined any of his own
handlers for this event.

• User-definable global handlers

The user can set up his own subroutines to replace the default actions for every IRC
connection managed by your program. These only get invoked if the user hasn't set up a
per-connection handler for the same event.

• User-definable per-connection handlers

Simple: this tells a single connection what to do if it gets an event of this type.
Supersedes global handlers if any are defined for this event.

And even better, you can choose to call your custom handlers before or after the default
handlers instead of replacing them, if you wish. In short, it's not perfect, but it's
about as good as you can get and still be documentable, given the sometimes horrendous
complexity of the IRC protocol.

GETTING STARTED

       Initialization

       To start a Net::IRC script, you need two things: a Net::IRC object, and a
       Net::IRC::Connection object. The Connection object does the dirty work of connecting to
       the server; the IRC object handles the input and output for it.  To that end, say
       something like this:

           use Net::IRC;

           $irc = new Net::IRC;

           $conn = $irc->newconn(Nick    => 'some_nick',
                                 Server  => 'some.irc.server.com');

       ...or something similar. Acceptable parameters to newconn() are:

       •   Nick

           The nickname you'll be known by on IRC, often limited to a maximum of 9 letters.
           Acceptable characters for a nickname are "[\w{}[]\`^|-]". If you don't specify a nick,
           it defaults to your username.

       •   Server

           The IRC server to connect to. There are dozens of them across several widely-used IRC
           networks, but the oldest and most popular is EFNet (Eris Free Net), home to #perl. See
           http://www.irchelp.org/ for lists of popular servers, or ask a friend.

       •   Port

           The port to connect to this server on. By custom, the default is 6667.

       •   Username

           On systems not running identd, you can set the username for your user@host to anything
           you wish. Note that some IRC servers won't allow connections from clients which don't
           run identd.

       •   Ircname

           A short (maybe 60 or so chars) piece of text, originally intended to display your real
           name, which people often use for pithy quotes and URLs. Defaults to the contents of
           your GECOS field.

       •   Password

           If the IRC server you're trying to write a bot for is password-protected, no problem.
           Just say ""Password =" 'foo'>" and you're set.

       •   SSL

           If you wish to connect to an irc server which is using SSL, set this to a true value.
           Ie: ""SSL =" 1>".

       Handlers

       Once that's over and done with, you need to set up some handlers if you want your bot to
       do anything more than sit on a connection and waste resources.  Handlers are references to
       subroutines which get called when a specific event occurs. Here's a sample handler sub:

           # What to do when the bot successfully connects.
           sub on_connect {
               my $self = shift;

               print "Joining #IRC.pm...";
               $self->join("#IRC.pm");
               $self->privmsg("#IRC.pm", "Hi there.");
           }

       The arguments to a handler function are always the same:

       $_[0]:
           The Connection object that's calling it.

       $_[1]:
           An Event object (see below) that describes what the handler is responding to.

       Got it? If not, see the examples in the irctest script that came with this distribution.
       Anyhow, once you've defined your handler subroutines, you need to add them to the list of
       handlers as either a global handler (affects all Connection objects) or a local handler
       (affects only a single Connection). To do so, say something along these lines:

           $self->add_global_handler('376', \&on_connect);     # global
           $self->add_handler('msg', \&on_msg);                # local

       376, incidentally, is the server number for "end of MOTD", which is an event that the
       server sends to you after you're connected. See Event.pm for a list of all possible
       numeric codes. The 'msg' event gets called whenever someone else on IRC sends your client
       a private message. For a big list of possible events, see the Event List section in the
       documentation for Net::IRC::Event.

       Getting Connected

       When you've set up all your handlers, the following command will put your program in an
       infinite loop, grabbing input from all open connections and passing it off to the proper
       handlers:

           $irc->start;

       Note that new connections can be added and old ones dropped from within your handlers even
       after you call this. Just don't expect any code below the call to "start()" to ever get
       executed.

       If you're tying Net::IRC into another event-based module, such as perl/Tk, there's a nifty
       "do_one_loop()" method provided for your convenience. Calling "$irc->do_one_loop()" runs
       through the IRC.pm event loop once, hands all ready filehandles over to the appropriate
       handler subs, then returns control to your program.

METHOD DESCRIPTIONS

       This section contains only the methods in IRC.pm itself. Lists of the methods in
       Net::IRC::Connection, Net::IRC::Event, or Net::IRC::DCC are in their respective modules'
       documentation; just "perldoc Net::IRC::Connection" (or Event or DCC or whatever) to read
       them. Functions take no arguments unless otherwise specified in their description.

       By the way, expect Net::IRC to use AutoLoader sometime in the future, once it becomes a
       little more stable.

       •   addconn()

           Adds the specified object's socket to the select loop in "do_one_loop()".  This is
           mostly for the use of Connection and DCC objects (and for pre-0.5 compatibility)...
           for most (read: all) purposes, you can just use "addfh()", described below.

           Takes at least 1 arg:

           0.  An object whose socket needs to be added to the select loop

           1.  Optional: A string consisting of one or more of the letters r, w, and e.  Passed
               directly to "addfh()"... see the description below for more info.

       •   addfh()

           This sub takes a user's socket or filehandle and a sub to handle it with and merges it
           into "do_one_loop()"'s list of select()able filehandles. This makes integration with
           other event-based systems (Tk, for instance) a good deal easier than in previous
           releases.

           Takes at least 2 args:

           0.  A socket or filehandle to monitor

           1.  A reference to a subroutine. When "select()" determines that the filehandle is
               ready, it passes the filehandle to this (presumably user-supplied) sub, where you
               can read from it, write to it, etc. as your script sees fit.

           2.  Optional: A string containing any combination of the letters r, w or e (standing
               for read, write, and error, respectively) which determines what conditions you're
               expecting on that filehandle. For example, this line select()s $fh (a filehandle,
               of course) for both reading and writing:

                   $irc->addfh( $fh, \&callback, "rw" );

       •   do_one_loop()

           "select()"s on all open filehandles and passes any ready ones to the appropriate
           handler subroutines. Also responsible for executing scheduled events from
           "Net::IRC::Connection->schedule()" on time.

       •   new()

           A fairly vanilla constructor which creates and returns a new Net::IRC object.

       •   newconn()

           Creates and returns a new Connection object. All arguments are passed straight to
           "Net::IRC::Connection->new()"; examples of common arguments can be found in the
           Synopsis or Getting Started sections.

       •   removeconn()

           Removes the specified object's socket from "do_one_loop()"'s list of select()able
           filehandles. This is mostly for the use of Connection and DCC objects (and for pre-0.5
           compatibility)... for most (read: all) purposes, you can just use "removefh()",
           described below.

           Takes 1 arg:

           0.  An object whose socket or filehandle needs to be removed from the select loop

       •   removefh()

           This method removes a given filehandle from "do_one_loop()"'s list of selectable
           filehandles.

           Takes 1 arg:

           0.  A socket or filehandle to remove

       •   start()

           Starts an infinite event loop which repeatedly calls "do_one_loop()" to read new
           events from all open connections and pass them off to any applicable handlers.

       •   timeout()

           Sets or returns the current "select()" timeout for the main event loop, in seconds
           (fractional amounts allowed). See the documentation for the "select()" function for
           more info.

           Takes 1 optional arg:

           0.  Optional: A new value for the "select()" timeout for this IRC object.

       •   flush_output_queue()

           Flushes any waiting messages in the output queue if pacing is enabled. This method
           will not return until the output queue is empty.

AUTHORS

       •   Conceived and initially developed by Greg Bacon <gbacon@adtran.com> and Dennis Taylor
           <dennis@funkplanet.com>.

       •   Ideas and large amounts of code donated by Nat "King" Torkington <gnat@frii.com>.

       •   Currently being hacked on, hacked up, and worked over by the members of the Net::IRC
           developers mailing list. For details, see http://www.execpc.com/~corbeau/irc/list.html
           .

URL

       Up-to-date source and information about the Net::IRC project can be found at
       http://www.sourceforge.net/projects/net-irc/ .

POD ERRORS

       Hey! The above document had some coding errors, which are explained below:

       Around line 697:
           You forgot a '=back' before '=head1'