IRC Hacks [Electronic resources] نسخه متنی

Hack 85 Understanding CTCP Messages

CTCP messages are used quite frequently on IRC.
Learn what they mean so you can use them effectively.

CTCP is the
Client-to-Client
Protocol, which is used over IRC to send structured data. In general,
a CTCP request will be sent as part of a PRIVMSG message [Hack #78] to a user or to a channel.
This message consists of a string of text between two ASCII 0x01
characters (ASCII character 1). There are two forms of CTCP messages:
tagged data and queries. Queries are also used to set up DCC
connections [Hack #69] .

13.9.1 Tagged Data

Tagged
data consists of specially tagged and formatted data used to send
special messages between clients. This is seldom used with modern IRC
clients, with the exception of the CTCP
ACTION command.

The original CTCP specification spoke of actions as being
"used by losers on IRC to simulate
`role-playing'
games." Actions are behind the /me
action command. The string is fairly simple and consists of
the ACTION command (all uppercase) followed by the
text of the action. For example:

\001ACTION jumps for joy!\001
\001ACTION is considering switching to Gentoo.\001
\001ACTION tries to recompile his kernel, but fails.\001

If the user Fennec is sending these messages, most IRC clients will
render these actions similar to this:

* Fennec jumps for joy!
* Fennec is considering switching to Gentoo.
* Fennec tries to recompile his kernel, but fails.

13.9.2 Queries

Several
simple
CTCP commands request information from someone else. When a client
receives these, it should reply with a CTCP command of the same name
sent to the originator via NOTICE (and not via
PRIVMSG). If your client does not understand a
CTCP query, it can be safely ignored.

Generally, a CTCP query is sent to an individual user. If you send a
CTCP command to a channel, you can expect a response from all the
clients on that channel. Doing this repeatedly is seldom appreciated
or advisable. If you receive a CTCP query from a channel, however,
you should reply only to the original sender.

An example command would be the following sent as
a PRIVMSG:

\001TIME\001

This would be the reply, but note that it would be sent as a
NOTICE:

\001TIME Sat Nov 12 1955 22:04:00 PST\001

Here are some valid CTCP queries:

CTCP VERSION

Requests the name and version of your IRC client. Replies should be
of the form CLIENT NAME:VERSION:ENVIRONMENT;
however, this exact format is often ignoredfor example:
mIRC v6.14 Khaled Mardam-Bey.

CTCP SOURCE

Rarely used and primarily historical, but it should return the
location of the source code for the IRC client.

CTCP PING

Used as a way to ping an individual client. Typically, the sending
machine will use the PING command with some
representation of the current time; the receiving machine is expected
to reply with an identical PING command, so it is
possible to work out how long it took to get the reply.

CTCP TIME

Requests the time. It should be replied to with a human-readable
string informing the user of the client's current
local time.

CTCP USERINFO

Should return a string set by the IRC user, presumably giving
information about the user.

CTCP CLIENTINFO

Should tell what tagged data a client is capable of handling. See RFC
1459 for more information on how this command should be used.

CTCP ERRMSG

Used to reply to a CTCP request that produces an error. When used as
a query, the reply should echo back the exact data produced by the
query, followed with an indication that no error has happened.

If you are running a PircBot-based bot, you may notice that it
automatically responds to some of these queries, such as
VERSION, PING, and
TIME. You can override the methods that are
responsible for replying, although it is a good idea to call the same
method in the superclass to ensure that the bot still responds
appropriately, for example:

public void onPing(String sourceNick, String sourceLogin,
String sourceHostname, String target, String pingValue) {
System.out.println("I got pinged by " + sourceNick);
// Make the PircBot super class perform its normal response to the PING.
super.onPing(sourceNick, sourceLogin, sourceHostname, target, pingValue);
}

You can override methods like this to find out which users are interested
in your bot.

Thomas Whaples