NAME
    IRC::Utils - Common utilities for IRC-related tasks

SYNOPSIS
     use strict;
     use warnings;

     use IRC::Utils ':ALL';

     my $nickname = '^Lame|BOT[moo]';
     my $uppercase_nick = u_irc($nickname);
     my $lowercase_nick = l_irc($nickname);

     my $mode_line = 'ov+b-i Bob sue stalin*!*@*';
     my $hashref = parse_mode_line($mode_line);

     my $banmask = 'stalin*';
     my $full_banmask = parse_mask($banmask);

     if (matches_mask($full_banmask, 'stalin!joe@kremlin.ru')) {
         print "EEK!";
     }

     my $decoded = irc_decode($raw_irc_message);
     print $decoded, "\n";

     if (has_color($message)) {
        print 'COLOR CODE ALERT!\n";
     }

     my $results_hashref = matches_mask_array(\@masks, \@items_to_match_against);

     my $nick = parse_user('stalin!joe@kremlin.ru');
     my ($nick, $user, $host) = parse_user('stalin!joe@kremlin.ru');

DESCRIPTION
    The functions in this module take care of many of the tasks you are
    faced with when working with IRC. Mode lines, ban masks, message
    encoding and formatting, etc.

FUNCTIONS
  "u_irc"
    Takes one mandatory parameter, a string to convert to IRC uppercase, and
    one optional parameter, the casemapping of the ircd (which can be
    'rfc1459', 'strict-rfc1459' or 'ascii'. Default is 'rfc1459'). Returns
    the IRC uppercase equivalent of the passed string.

  "l_irc"
    Takes one mandatory parameter, a string to convert to IRC lowercase, and
    one optional parameter, the casemapping of the ircd (which can be
    'rfc1459', 'strict-rfc1459' or 'ascii'. Default is 'rfc1459'). Returns
    the IRC lowercase equivalent of the passed string.

  "parse_mode_line"
    Takes a list representing an IRC mode line. Returns a hashref. If the
    modeline couldn't be parsed the hashref will be empty. On success the
    following keys will be available in the hashref:

    'modes', an arrayref of normalised modes;

    'args', an arrayref of applicable arguments to the modes;

    Example:

     my $hashref = parse_mode_line( 'ov+b-i', 'Bob', 'sue', 'stalin*!*@*' );

     # $hashref will be:
     {
        modes => [ '+o', '+v', '+b', '-i' ],
        args  => [ 'Bob', 'sue', 'stalin*!*@*' ],
     }

  "parse_mask"
    Takes one parameter, a string representing an IRC mask. Returns a
    normalised full mask.

    Example:

     $fullbanmask = parse_mask( 'stalin*' );

     # $fullbanmask will be: 'stalin*!*@*';

  "matches_mask"
    Takes two parameters, a string representing an IRC mask (it'll be
    processed with "parse_mask" to ensure that it is normalised) and
    something to match against the IRC mask, such as a nick!user@hostname
    string. Returns a true value if they match, a false value otherwise.
    Optionally, one may pass the casemapping (see "u_irc"), as this function
    uses "u_irc" internally.

  "matches_mask_array"
    Takes two array references, the first being a list of strings
    representing IRC masks, the second a list of somethings to test against
    the masks. Returns an empty hashref if there are no matches. Otherwise,
    the keys will be the masks matched, each value being an arrayref of the
    strings that matched it. Optionally, one may pass the casemapping (see
    "u_irc"), as this function uses "u_irc" internally.

  "unparse_mode_line"
    Takes one argument, a string representing a number of mode changes.
    Returns a condensed version of the changes.

      my $mode_line = unparse_mode_line('+o+o+o-v+v');
      $mode_line is now '+ooo-v+v'

  "gen_mode_change"
    Takes two arguments, strings representing a set of IRC user modes before
    and after a change. Returns a string representing what changed.

      my $mode_change = gen_mode_change('abcde', 'befmZ');
      $mode_change is now '-acd+fmZ'

  "parse_user"
    Takes one parameter, a string representing a user in the form
    nick!user@hostname. In a scalar context it returns just the nickname. In
    a list context it returns a list consisting of the nick, user and
    hostname, respectively.

  "is_valid_chan_name"
    Takes one argument, a channel name to validate. Returns true or false if
    the channel name is valid or not. You can supply a second argument, an
    array of characters of allowed channel prefixes. Defaults to "['#',
    '&']".

  "is_valid_nick_name"
    Takes one argument, a nickname to validate. Returns true or false if the
    nickname is valid or not.

  "numeric_to_name"
    Takes an IRC server numerical reply code (e.g. '001') as an argument,
    and returns the corresponding name (e.g. 'RPL_WELCOME').

  "name_to_numeric"
    Takes an IRC server reply name (e.g. 'RPL_WELCOME') as an argument, and
    returns the corresponding numerical code (e.g. '001').

  "has_color"
    Takes one parameter, a string of IRC text. Returns true if it contains
    any IRC color codes, false otherwise. Useful if you want your bot to
    kick users for (ab)using colors. :)

  "has_formatting"
    Takes one parameter, a string of IRC text. Returns true if it contains
    any IRC formatting codes, false otherwise.

  "strip_color"
    Takes one parameter, a string of IRC text. Returns the string stripped
    of all IRC color codes.

  "strip_formatting"
    Takes one parameter, a string of IRC text. Returns the string stripped
    of all IRC formatting codes.

  "decode_irc"
    This function takes a byte string (i.e. an unmodified IRC message) and
    and returns a text string. Since the source encoding might have been
    UTF-8, you should store it with UTF-8 or some other Unicode encoding in
    your file/database/whatever to be safe. For a more detailed discussion,
    see "ENCODING".

     use IRC::Utils qw(decode_irc);

     sub message_handler {
         my ($nick, $channel, $message) = @_;

         # not wise, $message is a byte string of unkown encoding
         print $message, "\n";

         $message = decode_irc($what);

         # good, $message is a text string
         print $message, "\n";
     }

CONSTANTS
    Use the following constants to add formatting and mIRC color codes to
    IRC messages.

    Normal text:

     NORMAL

    Formatting:

     BOLD
     UNDERLINE
     REVERSE
     ITALIC
     FIXED

    Colors:

     WHITE
     BLACK
     BLUE
     GREEN
     RED
     BROWN
     PURPLE
     ORANGE
     YELLOW
     LIGHT_GREEN
     TEAL
     LIGHT_CYAN
     LIGHT_BLUE
     PINK
     GREY
     LIGHT_GREY

    Individual non-color formatting codes can be cancelled with their
    corresponding constant, but you can also cancel all of them at once with
    "NORMAL". To cancel the effect of color codes, you must use "NORMAL".
    which of course has the side effect of cancelling all other formatting
    codes as well.

     $msg = 'This word is '.YELLOW.'yellow'.NORMAL.' while this word is'.BOLD.'bold'.BOLD;
     $msg = UNDERLINE.BOLD.'This sentence is both underlined and bold.'.NORMAL;

ENCODING
  Messages
    The only encoding requirement the IRC protocol places on its messages is
    that they be 8-bits and ASCII-compatible. This has resulted in most of
    the Western world settling on ASCII-compatible Latin-1 (usually
    Microsoft's CP1252, a Latin-1 variant) as a convention. Recently,
    popular IRC clients (mIRC, xchat, certain irssi configurations) have
    begun sending a mixture of CP1252 and UTF-8 over the wire to allow more
    characters without breaking backward compatibility (too much). They send
    CP1252 encoded messages if the characters fit within that encoding,
    otherwise falling back to UTF-8, and likewise autodetecting the encoding
    (UTF-8 or CP1252) of incoming messages. Since writing text with mixed
    encoding to a file, terminal, or database is not a good idea, you need a
    way to decode messages from IRC. "decode_irc" will do that.

  Channel names
    The matter is complicated further by the fact that some servers allow
    non-ASCII characters in channel names. IRC modules generally don't
    explicitly encode or decode any IRC traffic, but they do have to
    concatenate parts of a message (e.g. a channel name and a message)
    before sending it over the wire. So when you do something like
    "privmsg($channel, 'æði')", where $chanbel is the unmodified channel
    name (a byte string) you got from an earlier IRC message, the channel
    name will get double-encoded when concatenated with the message (a
    non-ASCII text string) if it contains non-ASCII bytes.

    To prevent this, you can't simply call "decode_irc" on the channel name
    and then use it. '#æði' in CP1252 is not the same channel as '#æði' in
    UTF-8, since they are represented as different strings of bytes. The
    channel name and your message must therefore both be byte strings, or
    both be text strings If they're text strings, the UTF-8 flag must be off
    for both, or on for both.

    A simple rule to follow is to call "encode_utf8" on any part (channel or
    message) which is a text string. Here are some examples:

     use Encode qw(encode_utf8);

     sub message_handler {
         # these three are all byte strings
         my ($nick, $channel, $message) = @_;

         # bad: if $channel has any non-ASCII bytes, they will get double-encoded
         privmsg($channel, 'æði');

         # bad: if $message has any non-ASCII bytes, they will get double-encoded
         privmsg('#æði', $message);

         # good: both are byte strings already, so they will concatenate correctly
         privmsg($channel, $message);

         # good: both are text strings (Latin1 as per Perl's default), so
         # they'll be concatenated correctly
         privmsg('#æði', 'æði');

         # good: similar to the last one, except now they're using UTF-8, which
         # means that the channel is actually not the same as above
         use utf8;
         privmsg('#æði', 'æði');

         # good: $channel and $msg_bytes are both byte strings
         my $msg_bytes = encode_utf8('æði');
         privmsg($channel, $msg_bytes);

         # good: $chan_bytes and $message are both byte strings
         my $chan_bytes = encode_utf8('#æði');
         privmsg($chan_bytes, $message);
     }

    See also Encode, perluniintro, perlunitut, perlunicode, and perlunifaq.

AUTHOR
    Chris "BinGOs" Williams <chris@bingosnet.co.uk>

    Hinrik Örn Sigurðsson <hinrik.sig@gmail.com>

SEE ALSO
    POE::Component::IRC

    POE::Component::Server::IRC

