RFC 1459

Network Working Group J. Oikarinen

Request for Comments: 1459 D. Reed

May 1993



Internet Relay Chat Protocol


Status of This Memo


This memo defines an Experimental Protocol for the Internet

community. Discussion and suggestions for improvement are requested.

Please refer to the current edition of the "IAB Official Protocol

Standards" for the standardization state and status of this protocol.

Distribution of this memo is unlimited.


Abstract


The IRC protocol was developed over the last 4 years since it was

first implemented as a means for users on a BBS to chat amongst

themselves. Now it supports a world-wide network of servers and

clients, and is stringing to cope with growth. Over the past 2 years,

the average number of users connected to the main IRC network has

grown by a factor of 10.


The IRC protocol is a text-based protocol, with the simplest client

being any socket program capable of connecting to the server.


Table of Contents


1. INTRODUCTION ............................................... 4

1.1 Servers ................................................ 4

1.2 Clients ................................................ 5

1.2.1 Operators .......................................... 5

1.3 Channels ................................................ 5

1.3.1 Channel Operators .................................... 6

2. THE IRC SPECIFICATION ....................................... 7

2.1 Overview ................................................ 7

2.2 Character codes ......................................... 7

2.3 Messages ................................................ 7

2.3.1 Message format in 'pseudo' BNF .................... 8

2.4 Numeric replies ......................................... 10

3. IRC Concepts ................................................ 10

3.1 One-to-one communication ................................ 10

3.2 One-to-many ............................................. 11

3.2.1 To a list .......................................... 11

3.2.2 To a group (channel) ............................... 11

3.2.3 To a host/server mask .............................. 12

3.3 One to all .............................................. 12




Oikarinen & Reed [Page 1]

RFC 1459 Internet Relay Chat Protocol May 1993



3.3.1 Client to Client ................................... 12

3.3.2 Clients to Server .................................. 12

3.3.3 Server to Server ................................... 12

4. MESSAGE DETAILS ............................................. 13

4.1 Connection Registration ................................. 13

4.1.1 Password message ................................... 14

4.1.2 Nickname message ................................... 14

4.1.3 User message ....................................... 15

4.1.4 Server message ..................................... 16

4.1.5 Operator message ................................... 17

4.1.6 Quit message ....................................... 17

4.1.7 Server Quit message ................................ 18

4.2 Channel operations ...................................... 19

4.2.1 Join message ....................................... 19

4.2.2 Part message ....................................... 20

4.2.3 Mode message ....................................... 21

4.2.3.1 Channel modes ................................. 21

4.2.3.2 User modes .................................... 22

4.2.4 Topic message ...................................... 23

4.2.5 Names message ...................................... 24

4.2.6 List message ....................................... 24

4.2.7 Invite message ..................................... 25

4.2.8 Kick message ....................................... 25

4.3 Server queries and commands ............................. 26

4.3.1 Version message .................................... 26

4.3.2 Stats message ...................................... 27

4.3.3 Links message ...................................... 28

4.3.4 Time message ....................................... 29

4.3.5 Connect message .................................... 29

4.3.6 Trace message ...................................... 30

4.3.7 Admin message ...................................... 31

4.3.8 Info message ....................................... 31

4.4 Sending messages ........................................ 32

4.4.1 Private messages ................................... 32

4.4.2 Notice messages .................................... 33

4.5 User-based queries ...................................... 33

4.5.1 Who query .......................................... 33

4.5.2 Whois query ........................................ 34

4.5.3 Whowas message ..................................... 35

4.6 Miscellaneous messages .................................. 35

4.6.1 Kill message ....................................... 36

4.6.2 Ping message ....................................... 37

4.6.3 Pong message ....................................... 37

4.6.4 Error message ...................................... 38

5. OPTIONAL MESSAGES ........................................... 38

5.1 Away message ............................................ 38

5.2 Rehash command .......................................... 39

5.3 Restart command ......................................... 39




Oikarinen & Reed [Page 2]

RFC 1459 Internet Relay Chat Protocol May 1993



5.4 Summon message .......................................... 40

5.5 Users message ........................................... 40

5.6 Operwall command ........................................ 41

5.7 Userhost message ........................................ 42

5.8 Ison message ............................................ 42

6. REPLIES ..................................................... 43

6.1 Error Replies ........................................... 43

6.2 Command responses ....................................... 48

6.3 Reserved numerics ....................................... 56

7. Client and server authentication ............................ 56

8. Current Implementations Details ............................. 56

8.1 Network protocol: TCP ................................... 57

8.1.1 Support of Unix sockets ............................ 57

8.2 Command Parsing ......................................... 57

8.3 Message delivery ........................................ 57

8.4 Connection 'Liveness' ................................... 58

8.5 Establishing a server-client connection ................. 58

8.6 Establishing a server-server connection ................. 58

8.6.1 State information exchange when connecting ......... 59

8.7 Terminating server-client connections ................... 59

8.8 Terminating server-server connections ................... 59

8.9 Tracking nickname changes ............................... 60

8.10 Flood control of clients ............................... 60

8.11 Non-blocking lookups ................................... 61

8.11.1 Hostname (DNS) lookups ............................ 61

8.11.2 Username (Ident) lookups .......................... 61

8.12 Configuration file ..................................... 61

8.12.1 Allowing clients to connect ....................... 62

8.12.2 Operators ......................................... 62

8.12.3 Allowing servers to connect ....................... 62

8.12.4 Administrivia ..................................... 63

8.13 Channel membership ..................................... 63

9. Current problems ............................................ 63

9.1 Scalability ............................................. 63

9.2 Labels .................................................. 63

9.2.1 Nicknames .......................................... 63

9.2.2 Channels ........................................... 64

9.2.3 Servers ............................................ 64

9.3 Algorithms .............................................. 64

10. Support and availability ................................... 64

11. Security Considerations .................................... 65

12. Authors' Addresses ......................................... 65










Oikarinen & Reed [Page 3]

RFC 1459 Internet Relay Chat Protocol May 1993



1. INTRODUCTION


The IRC (Internet Relay Chat) protocol has been designed over a

number of years for use with text based conferencing. This document

describes the current IRC protocol.


The IRC protocol has been developed on systems using the TCP/IP

network protocol, although there is no requirement that this remain

the only sphere in which it operates.


IRC itself is a teleconferencing system, which (through the use of

the client-server model) is well-suited to running on many machines

in a distributed fashion. A typical setup involves a single process

(the server) forming a central point for clients (or other servers)

to connect to, performing the required message delivery/multiplexing

and other functions.


1.1 Servers


The server forms the backbone of IRC, providing a point to which

clients may connect to to talk to each other, and a point for other

servers to connect to, forming an IRC network. The only network

configuration allowed for IRC servers is that of a spanning tree [see

Fig. 1] where each server acts as a central node for the rest of the

net it sees.



[ Server 15 ] [ Server 13 ] [ Server 14]

/ \ /

/ \ /

[ Server 11 ] ------ [ Server 1 ] [ Server 12]

/ \ /

/ \ /

[ Server 2 ] [ Server 3 ]

/ \ \

/ \ \

[ Server 4 ] [ Server 5 ] [ Server 6 ]

/ | \ /

/ | \ /

/ | \____ /

/ | \ /

[ Server 7 ] [ Server 8 ] [ Server 9 ] [ Server 10 ]


:

[ etc. ]

:


[ Fig. 1. Format of IRC server network ]




Oikarinen & Reed [Page 4]

RFC 1459 Internet Relay Chat Protocol May 1993



1.2 Clients


A client is anything connecting to a server that is not another

server. Each client is distinguished from other clients by a unique

nickname having a maximum length of nine (9) characters. See the

protocol grammar rules for what may and may not be used in a

nickname. In addition to the nickname, all servers must have the

following information about all clients: the real name of the host

that the client is running on, the username of the client on that

host, and the server to which the client is connected.


1.2.1 Operators


To allow a reasonable amount of order to be kept within the IRC

network, a special class of clients (operators) is allowed to perform

general maintenance functions on the network. Although the powers

granted to an operator can be considered as 'dangerous', they are

nonetheless required. Operators should be able to perform basic

network tasks such as disconnecting and reconnecting servers as

needed to prevent long-term use of bad network routing. In

recognition of this need, the protocol discussed herein provides for

operators only to be able to perform such functions. See sections

4.1.7 (SQUIT) and 4.3.5 (CONNECT).


A more controversial power of operators is the ability to remove a

user from the connected network by 'force', i.e. operators are able

to close the connection between any client and server. The

justification for this is delicate since its abuse is both

destructive and annoying. For further details on this type of

action, see section 4.6.1 (KILL).


1.3 Channels


A channel is a named group of one or more clients which will all

receive messages addressed to that channel. The channel is created

implicitly when the first client joins it, and the channel ceases to

exist when the last client leaves it. While channel exists, any

client can reference the channel using the name of the channel.


Channels names are strings (beginning with a '&' or '#' character) of

length up to 200 characters. Apart from the the requirement that the

first character being either '&' or '#'; the only restriction on a

channel name is that it may not contain any spaces (' '), a control G

(^G or ASCII 7), or a comma (',' which is used as a list item

separator by the protocol).


There are two types of channels allowed by this protocol. One is a

distributed channel which is known to all the servers that are




Oikarinen & Reed [Page 5]

RFC 1459 Internet Relay Chat Protocol May 1993



connected to the network. These channels are marked by the first

character being a only clients on the server where it exists may join

it. These are distinguished by a leading '&' character. On top of

these two types, there are the various channel modes available to

alter the characteristics of individual channels. See section 4.2.3

(MODE command) for more details on this.


To create a new channel or become part of an existing channel, a user

is required to JOIN the channel. If the channel doesn't exist prior

to joining, the channel is created and the creating user becomes a

channel operator. If the channel already exists, whether or not your

request to JOIN that channel is honoured depends on the current modes

of the channel. For example, if the channel is invite-only, (+i),

then you may only join if invited. As part of the protocol, a user

may be a part of several channels at once, but a limit of ten (10)

channels is recommended as being ample for both experienced and

novice users. See section 8.13 for more information on this.


If the IRC network becomes disjoint because of a split between two

servers, the channel on each side is only composed of those clients

which are connected to servers on the respective sides of the split,

possibly ceasing to exist on one side of the split. When the split

is healed, the connecting servers announce to each other who they

think is in each channel and the mode of that channel. If the

channel exists on both sides, the JOINs and MODEs are interpreted in

an inclusive manner so that both sides of the new connection will

agree about which clients are in the channel and what modes the

channel has.


1.3.1 Channel Operators


The channel operator (also referred to as a "chop" or "chanop") on a

given channel is considered to 'own' that channel. In recognition of

this status, channel operators are endowed with certain powers which

enable them to keep control and some sort of sanity in their channel.

As an owner of a channel, a channel operator is not required to have

reasons for their actions, although if their actions are generally

antisocial or otherwise abusive, it might be reasonable to ask an IRC

operator to intervene, or for the usersjust leave and go elsewhere

and form their own channel.


The commands which may only be used by channel operators are:


KICK - Eject a client from the channel

MODE - Change the channel's mode

INVITE - Invite a client to an invite-only channel (mode +i)

TOPIC - Change the channel topic in a mode +t channel





Oikarinen & Reed [Page 6]

RFC 1459 Internet Relay Chat Protocol May 1993



A channel operator is identified by the '@' symbol next to their

nickname whenever it is associated with a channel (ie replies to the

NAMES, WHO and WHOIS commands).


2. The IRC Specification


2.1 Overview


The protocol as described herein is for use both with server to

server and client to server connections. There are, however, more

restrictions on client connections (which are considered to be

untrustworthy) than on server connections.


2.2 Character codes


No specific character set is specified. The protocol is based on a a

set of codes which are composed of eight (8) bits, making up an

octet. Each message may be composed of any number of these octets;

however, some octet values are used for control codes which act as

message delimiters.


Regardless of being an 8-bit protocol, the delimiters and keywords

are such that protocol is mostly usable from USASCII terminal and a

telnet connection.


Because of IRC's scandanavian origin, the characters {}| are

considered to be the lower case equivalents of the characters []\,

respectively. This is a critical issue when determining the

equivalence of two nicknames.


2.3 Messages


Servers and clients send eachother messages which may or may not

generate a reply. If the message contains a valid command, as

described in later sections, the client should expect a reply as

specified but it is not advised to wait forever for the reply; client

to server and server to server communication is essentially

asynchronous in nature.


Each IRC message may consist of up to three main parts: the prefix

(optional), the command, and the command parameters (of which there

may be up to 15). The prefix, command, and all parameters are

separated by one (or more) ASCII space character(s) (0x20).


The presence of a prefix is indicated with a single leading ASCII

colon character (':', 0x3b), which must be the first character of the

message itself. There must be no gap (whitespace) between the colon

and the prefix. The prefix is used by servers to indicate the true




Oikarinen & Reed [Page 7]

RFC 1459 Internet Relay Chat Protocol May 1993



origin of the message. If the prefix is missing from the message, it

is assumed to have originated from the connection from which it was

received. Clients should not use prefix when sending a message from

themselves; if they use a prefix, the only valid prefix is the

registered nickname associated with the client. If the source

identified by the prefix cannot be found from the server's internal

database, or if the source is registered from a different link than

from which the message arrived, the server must ignore the message

silently.


The command must either be a valid IRC command or a three (3) digit

number represented in ASCII text.


IRC messages are always lines of characters terminated with a CR-LF

(Carriage Return - Line Feed) pair, and these messages shall not

exceed 512 characters in length, counting all characters including

the trailing CR-LF. Thus, there are 510 characters maximum allowed

for the command and its parameters. There is no provision for

continuation message lines. See section 7 for more details about

current implementations.


2.3.1 Message format in 'pseudo' BNF


The protocol messages must be extracted from the contiguous stream of

octets. The current solution is to designate two characters, CR and

LF, as message separators. Empty messages are silently ignored,

which permits use of the sequence CR-LF between messages

without extra problems.


The extracted message is parsed into the components <prefix>,

<command> and list of parameters matched either by <middle> or

<trailing> components.


The BNF representation for this is:



<message> ::= [':' <prefix> <SPACE> ] <command> <params> <crlf>

<prefix> ::= <servername> | <nick> [ '!' <user> ] [ '@' <host> ]

<command> ::= <letter> { <letter> } | <number> <number> <number>

<SPACE> ::= ' ' { ' ' }

<params> ::= <SPACE> [ ':' <trailing> | <middle> <params> ]


<middle> ::= <Any *non-empty* sequence of octets not including SPACE

or NUL or CR or LF, the first of which may not be ':'>

<trailing> ::= <Any, possibly *empty*, sequence of octets not including

NUL or CR or LF>


<crlf> ::= CR LF




Oikarinen & Reed [Page 8]

RFC 1459 Internet Relay Chat Protocol May 1993



NOTES:


1) <SPACE> is consists only of SPACE character(s) (0x20).

Specially notice that TABULATION, and all other control

characters are considered NON-WHITE-SPACE.


2) After extracting the parameter list, all parameters are equal,

whether matched by <middle> or <trailing>. <Trailing> is just

a syntactic trick to allow SPACE within parameter.


3) The fact that CR and LF cannot appear in parameter strings is

just artifact of the message framing. This might change later.


4) The NUL character is not special in message framing, and

basically could end up inside a parameter, but as it would

cause extra complexities in normal C string handling. Therefore

NUL is not allowed within messages.


5) The last parameter may be an empty string.


6) Use of the extended prefix (['!' <user> ] ['@' <host> ]) must

not be used in server to server communications and is only

intended for server to client messages in order to provide

clients with more useful information about who a message is

from without the need for additional queries.


Most protocol messages specify additional semantics and syntax for

the extracted parameter strings dictated by their position in the

list. For example, many server commands will assume that the first

parameter after the command is the list of targets, which can be

described with:


<target> ::= <to> [ "," <target> ]

<to> ::= <channel> | <user> '@' <servername> | <nick> | <mask>

<channel> ::= ('#' | '&') <chstring>

<servername> ::= <host>

<host> ::= see RFC 952 [DNS:4] for details on allowed hostnames

<nick> ::= <letter> { <letter> | <number> | <special> }

<mask> ::= ('#' | '$') <chstring>

<chstring> ::= <any 8bit code except SPACE, BELL, NUL, CR, LF and

comma (',')>


Other parameter syntaxes are:


<user> ::= <nonwhite> { <nonwhite> }

<letter> ::= 'a' ... 'z' | 'A' ... 'Z'

<number> ::= '0' ... '9'

<special> ::= '-' | '[' | ']' | '\' | '`' | '^' | '{' | '}'




Oikarinen & Reed [Page 9]

RFC 1459 Internet Relay Chat Protocol May 1993



<nonwhite> ::= <any 8bit code except SPACE (0x20), NUL (0x0), CR

(0xd), and LF (0xa)>


2.4 Numeric replies


Most of the messages sent to the server generate a reply of some

sort. The most common reply is the numeric reply, used for both

errors and normal replies. The numeric reply must be sent as one

message consisting of the sender prefix, the three digit numeric, and

the target of the reply. A numeric reply is not allowed to originate

from a client; any such messages received by a server are silently

dropped. In all other respects, a numeric reply is just like a normal

message, except that the keyword is made up of 3 numeric digits

rather than a string of letters. A list of different replies is

supplied in section 6.


3. IRC Concepts.


This section is devoted to describing the actual concepts behind the

organization of the IRC protocol and how the current

implementations deliver different classes of messages.




1--\

A D---4

2--/ \ /

B----C

/ \

3 E


Servers: A, B, C, D, E Clients: 1, 2, 3, 4


[ Fig. 2. Sample small IRC network ]


3.1 One-to-one communication


Communication on a one-to-one basis is usually only performed by

clients, since most server-server traffic is not a result of servers

talking only to each other. To provide a secure means for clients to

talk to each other, it is required that all servers be able to send a

message in exactly one direction along the spanning tree in order to

reach any client. The path of a message being delivered is the

shortest path between any two points on the spanning tree.


The following examples all refer to Figure 2 above.






Oikarinen & Reed [Page 10]

RFC 1459 Internet Relay Chat Protocol May 1993



Example 1:

A message between clients 1 and 2 is only seen by server A, which

sends it straight to client 2.


Example 2:

A message between clients 1 and 3 is seen by servers A & B, and

client 3. No other clients or servers are allowed see the message.


Example 3:

A message between clients 2 and 4 is seen by servers A, B, C & D

and client 4 only.


3.2 One-to-many


The main goal of IRC is to provide a forum which allows easy and

efficient conferencing (one to many conversations). IRC offers

several means to achieve this, each serving its own purpose.


3.2.1 To a list


The least efficient style of one-to-many conversation is through

clients talking to a 'list' of users. How this is done is almost

self explanatory: the client gives a list of destinations to which

the message is to be delivered and the server breaks it up and

dispatches a separate copy of the message to each given destination.

This isn't as efficient as using a group since the destination list

is broken up and the dispatch sent without checking to make sure

duplicates aren't sent down each path.


3.2.2 To a group (channel)


In IRC the channel has a role equivalent to that of the multicast

group; their existence is dynamic (coming and going as people join

and leave channels) and the actual conversation carried out on a

channel is only sent to servers which are supporting users on a given

channel. If there are multiple users on a server in the same

channel, the message text is sent only once to that server and then

sent to each client on the channel. This action is then repeated for

each client-server combination until the original message has fanned

out and reached each member of the channel.


The following examples all refer to Figure 2.


Example 4:

Any channel with 1 client in it. Messages to the channel go to the

server and then nowhere else.






Oikarinen & Reed [Page 11]

RFC 1459 Internet Relay Chat Protocol May 1993



Example 5:

2 clients in a channel. All messages traverse a path as if they

were private messages between the two clients outside a channel.


Example 6:

Clients 1, 2 and 3 in a channel. All messages to the channel are

sent to all clients and only those servers which must be traversed

by the message if it were a private message to a single client. If

client 1 sends a message, it goes back to client 2 and then via

server B to client 3.


3.2.3 To a host/server mask


To provide IRC operators with some mechanism to send messages to a

large body of related users, host and server mask messages are

provided. These messages are sent to users whose host or server

information match that of the mask. The messages are only sent to

locations where users are, in a fashion similar to that of channels.


3.3 One-to-all


The one-to-all type of message is better described as a broadcast

message, sent to all clients or servers or both. On a large network

of users and servers, a single message can result in a lot of traffic

being sent over the network in an effort to reach all of the desired

destinations.


For some messages, there is no option but to broadcast it to all

servers so that the state information held by each server is

reasonably consistent between servers.


3.3.1 Client-to-Client


There is no class of message which, from a single message, results in

a message being sent to every other client.


3.3.2 Client-to-Server


Most of the commands which result in a change of state information

(such as channel membership, channel mode, user status, etc) must be

sent to all servers by default, and this distribution may not be

changed by the client.


3.3.3 Server-to-Server.


While most messages between servers are distributed to all 'other'

servers, this is only required for any message that affects either a

user, channel or server. Since these are the basic items found in




Oikarinen & Reed [Page 12]

RFC 1459 Internet Relay Chat Protocol May 1993



IRC, nearly all messages originating from a server are broadcast to

all other connected servers.


4. Message details


On the following pages are descriptions of each message recognized by

the IRC server and client. All commands described in this section

must be implemented by any server for this protocol.


Where the reply ERR_NOSUCHSERVER is listed, it means that the

<server> parameter could not be found. The server must not send any

other replies after this for that command.


The server to which a client is connected is required to parse the

complete message, returning any appropriate errors. If the server

encounters a fatal error while parsing a message, an error must be

sent back to the client and the parsing terminated. A fatal error

may be considered to be incorrect command, a destination which is

otherwise unknown to the server (server, nick or channel names fit

this category), not enough parameters or incorrect privileges.


If a full set of parameters is presented, then each must be checked

for validity and appropriate responses sent back to the client. In

the case of messages which use parameter lists using the comma as an

item separator, a reply must be sent for each item.


In the examples below, some messages appear using the full format:


:Name COMMAND parameter list


Such examples represent a message from "Name" in transit between

servers, where it is essential to include the name of the original

sender of the message so remote servers may send back a reply along

the correct path.


4.1 Connection Registration


The commands described here are used to register a connection with an

IRC server as either a user or a server as well as correctly

disconnect.


A "PASS" command is not required for either client or server

connection to be registered, but it must precede the server message

or the latter of the NICK/USER combination. It is strongly

recommended that all server connections have a password in order to

give some level of security to the actual connections. The

recommended order for a client to register is as follows:





Oikarinen & Reed [Page 13]

RFC 1459 Internet Relay Chat Protocol May 1993



1. Pass message

2. Nick message

3. User message


4.1.1 Password message



Command: PASS

Parameters: <password>


The PASS command is used to set a 'connection password'. The

password can and must be set before any attempt to register the

connection is made. Currently this requires that clients send a PASS

command before sending the NICK/USER combination and servers *must*

send a PASS command before any SERVER command. The password supplied

must match the one contained in the C/N lines (for servers) or I

lines (for clients). It is possible to send multiple PASS commands

before registering but only the last one sent is used for

verification and it may not be changed once registered. Numeric

Replies:


ERR_NEEDMOREPARAMS ERR_ALREADYREGISTRED


Example:


PASS secretpasswordhere


4.1.2 Nick message


Command: NICK

Parameters: <nickname> [ <hopcount> ]


NICK message is used to give user a nickname or change the previous

one. The <hopcount> parameter is only used by servers to indicate

how far away a nick is from its home server. A local connection has

a hopcount of 0. If supplied by a client, it must be ignored.


If a NICK message arrives at a server which already knows about an

identical nickname for another client, a nickname collision occurs.

As a result of a nickname collision, all instances of the nickname

are removed from the server's database, and a KILL command is issued

to remove the nickname from all other server's database. If the NICK

message causing the collision was a nickname change, then the

original (old) nick must be removed as well.


If the server recieves an identical NICK from a client which is

directly connected, it may issue an ERR_NICKCOLLISION to the local

client, drop the NICK command, and not generate any kills.




Oikarinen & Reed [Page 14]

RFC 1459 Internet Relay Chat Protocol May 1993



Numeric Replies:


ERR_NONICKNAMEGIVEN ERR_ERRONEUSNICKNAME

ERR_NICKNAMEINUSE ERR_NICKCOLLISION


Example:


NICK Wiz ; Introducing new nick "Wiz".


:WiZ NICK Kilroy ; WiZ changed his nickname to Kilroy.


4.1.3 User message


Command: USER

Parameters: <username> <hostname> <servername> <realname>


The USER message is used at the beginning of connection to specify

the username, hostname, servername and realname of s new user. It is

also used in communication between servers to indicate new user

arriving on IRC, since only after both USER and NICK have been

received from a client does a user become registered.


Between servers USER must to be prefixed with client's NICKname.

Note that hostname and servername are normally ignored by the IRC

server when the USER command comes from a directly connected client

(for security reasons), but they are used in server to server

communication. This means that a NICK must always be sent to a

remote server when a new user is being introduced to the rest of the

network before the accompanying USER is sent.


It must be noted that realname parameter must be the last parameter,

because it may contain space characters and must be prefixed with a

colon (':') to make sure this is recognised as such.


Since it is easy for a client to lie about its username by relying

solely on the USER message, the use of an "Identity Server" is

recommended. If the host which a user connects from has such a

server enabled the username is set to that as in the reply from the

"Identity Server".


Numeric Replies:


ERR_NEEDMOREPARAMS ERR_ALREADYREGISTRED


Examples:



USER guest tolmoon tolsun :Ronnie Reagan




Oikarinen & Reed [Page 15]

RFC 1459 Internet Relay Chat Protocol May 1993



; User registering themselves with a

username of "guest" and real name

"Ronnie Reagan".



:testnick USER guest tolmoon tolsun :Ronnie Reagan

; message between servers with the

nickname for which the USER command

belongs to


4.1.4 Server message


Command: SERVER

Parameters: <servername> <hopcount> <info>


The server message is used to tell a server that the other end of a

new connection is a server. This message is also used to pass server

data over whole net. When a new server is connected to net,

information about it be broadcast to the whole network. <hopcount>

is used to give all servers some internal information on how far away

all servers are. With a full server list, it would be possible to

construct a map of the entire server tree, but hostmasks prevent this

from being done.


The SERVER message must only be accepted from either (a) a connection

which is yet to be registered and is attempting to register as a

server, or (b) an existing connection to another server, in which

case the SERVER message is introducing a new server behind that

server.


Most errors that occur with the receipt of a SERVER command result in

the connection being terminated by the destination host (target

SERVER). Error replies are usually sent using the "ERROR" command

rather than the numeric since the ERROR command has several useful

properties which make it useful here.


If a SERVER message is parsed and attempts to introduce a server

which is already known to the receiving server, the connection from

which that message must be closed (following the correct procedures),

since a duplicate route to a server has formed and the acyclic nature

of the IRC tree broken.


Numeric Replies:


ERR_ALREADYREGISTRED


Example:





Oikarinen & Reed [Page 16]

RFC 1459 Internet Relay Chat Protocol May 1993



SERVER test.oulu.fi 1 :[tolsun.oulu.fi] Experimental server

; New server test.oulu.fi introducing

itself and attempting to register. The

name in []'s is the hostname for the

host running test.oulu.fi.



:tolsun.oulu.fi SERVER csd.bu.edu 5 :BU Central Server

; Server tolsun.oulu.fi is our uplink

for csd.bu.edu which is 5 hops away.


4.1.5 Oper


Command: OPER

Parameters: <user> <password>


OPER message is used by a normal user to obtain operator privileges.

The combination of <user> and <password> are required to gain

Operator privileges.


If the client sending the OPER command supplies the correct password

for the given user, the server then informs the rest of the network

of the new operator by issuing a "MODE +o" for the clients nickname.


The OPER message is client-server only.


Numeric Replies:


ERR_NEEDMOREPARAMS RPL_YOUREOPER

ERR_NOOPERHOST ERR_PASSWDMISMATCH


Example:


OPER foo bar ; Attempt to register as an operator

using a username of "foo" and "bar" as

the password.


4.1.6 Quit


Command: QUIT

Parameters: [<Quit message>]


A client session is ended with a quit message. The server must close

the connection to a client which sends a QUIT message. If a "Quit

Message" is given, this will be sent instead of the default message,

the nickname.


When netsplits (disconnecting of two servers) occur, the quit message




Oikarinen & Reed [Page 17]

RFC 1459 Internet Relay Chat Protocol May 1993



is composed of the names of two servers involved, separated by a

space. The first name is that of the server which is still connected

and the second name is that of the server that has become

disconnected.


If, for some other reason, a client connection is closed without the

client issuing a QUIT command (e.g. client dies and EOF occurs

on socket), the server is required to fill in the quit message with

some sort of message reflecting the nature of the event which

caused it to happen.


Numeric Replies:


None.


Examples:


QUIT :Gone to have lunch ; Preferred message format.


4.1.7 Server quit message


Command: SQUIT

Parameters: <server> <comment>


The SQUIT message is needed to tell about quitting or dead servers.

If a server wishes to break the connection to another server it must

send a SQUIT message to the other server, using the the name of the

other server as the server parameter, which then closes its

connection to the quitting server.


This command is also available operators to help keep a network of

IRC servers connected in an orderly fashion. Operators may also

issue an SQUIT message for a remote server connection. In this case,

the SQUIT must be parsed by each server inbetween the operator and

the remote server, updating the view of the network held by each

server as explained below.


The <comment> should be supplied by all operators who execute a SQUIT

for a remote server (that is not connected to the server they are

currently on) so that other operators are aware for the reason of

this action. The <comment> is also filled in by servers which may

place an error or similar message here.


Both of the servers which are on either side of the connection being

closed are required to to send out a SQUIT message (to all its other

server connections) for all other servers which are considered to be

behind that link.





Oikarinen & Reed [Page 18]

RFC 1459 Internet Relay Chat Protocol May 1993



Similarly, a QUIT message must be sent to the other connected servers

rest of the network on behalf of all clients behind that link. In

addition to this, all channel members of a channel which lost a

member due to the split must be sent a QUIT message.


If a server connection is terminated prematurely (e.g. the server on

the other end of the link died), the server which detects

this disconnection is required to inform the rest of the network

that the connection has closed and fill in the comment field

with something appropriate.


Numeric replies:


ERR_NOPRIVILEGES ERR_NOSUCHSERVER


Example:


SQUIT tolsun.oulu.fi :Bad Link ? ; the server link tolson.oulu.fi has

been terminated because of "Bad Link".


:Trillian SQUIT cm22.eng.umd.edu :Server out of control

; message from Trillian to disconnect

"cm22.eng.umd.edu" from the net

because "Server out of control".


4.2 Channel operations


This group of messages is concerned with manipulating channels, their

properties (channel modes), and their contents (typically clients).

In implementing these, a number of race conditions are inevitable

when clients at opposing ends of a network send commands which will

ultimately clash. It is also required that servers keep a nickname

history to ensure that wherever a <nick> parameter is given, the

server check its history in case it has recently been changed.


4.2.1 Join message


Command: JOIN

Parameters: <channel>{,<channel>} [<key>{,<key>}]


The JOIN command is used by client to start listening a specific

channel. Whether or not a client is allowed to join a channel is

checked only by the server the client is connected to; all other

servers automatically add the user to the channel when it is received

from other servers. The conditions which affect this are as follows:


1. the user must be invited if the channel is invite-only;





Oikarinen & Reed [Page 19]

RFC 1459 Internet Relay Chat Protocol May 1993



2. the user's nick/username/hostname must not match any

active bans;


3. the correct key (password) must be given if it is set.


These are discussed in more detail under the MODE command (see

section 4.2.3 for more details).


Once a user has joined a channel, they receive notice about all

commands their server receives which affect the channel. This

includes MODE, KICK, PART, QUIT and of course PRIVMSG/NOTICE. The

JOIN command needs to be broadcast to all servers so that each server

knows where to find the users who are on the channel. This allows

optimal delivery of PRIVMSG/NOTICE messages to the channel.


If a JOIN is successful, the user is then sent the channel's topic

(using RPL_TOPIC) and the list of users who are on the channel (using

RPL_NAMREPLY), which must include the user joining.


Numeric Replies:


ERR_NEEDMOREPARAMS ERR_BANNEDFROMCHAN

ERR_INVITEONLYCHAN ERR_BADCHANNELKEY

ERR_CHANNELISFULL ERR_BADCHANMASK

ERR_NOSUCHCHANNEL ERR_TOOMANYCHANNELS

RPL_TOPIC


Examples:


JOIN #foobar ; join channel #foobar.


JOIN &foo fubar ; join channel &foo using key "fubar".


JOIN #foo,&bar fubar ; join channel #foo using key "fubar"

and &bar using no key.


JOIN #foo,#bar fubar,foobar ; join channel #foo using key "fubar".

and channel #bar using key "foobar".


JOIN #foo,#bar ; join channels #foo and #bar.


:WiZ JOIN #Twilight_zone ; JOIN message from WiZ


4.2.2 Part message


Command: PART

Parameters: <channel>{,<channel>}





Oikarinen & Reed [Page 20]

RFC 1459 Internet Relay Chat Protocol May 1993



The PART message causes the client sending the message to be removed

from the list of active users for all given channels listed in the

parameter string.


Numeric Replies:


ERR_NEEDMOREPARAMS ERR_NOSUCHCHANNEL

ERR_NOTONCHANNEL


Examples:


PART #twilight_zone ; leave channel "#twilight_zone"


PART #oz-ops,&group5 ; leave both channels "&group5" and

"#oz-ops".


4.2.3 Mode message


Command: MODE


The MODE command is a dual-purpose command in IRC. It allows both

usernames and channels to have their mode changed. The rationale for

this choice is that one day nicknames will be obsolete and the

equivalent property will be the channel.


When parsing MODE messages, it is recommended that the entire message

be parsed first and then the changes which resulted then passed on.


4.2.3.1 Channel modes


Parameters: <channel> {[+|-]|o|p|s|i|t|n|b|v} [<limit>] [<user>]

[<ban mask>]


The MODE command is provided so that channel operators may change the

characteristics of `their' channel. It is also required that servers

be able to change channel modes so that channel operators may be

created.


The various modes available for channels are as follows:


o - give/take channel operator privileges;

p - private channel flag;

s - secret channel flag;

i - invite-only channel flag;

t - topic settable by channel operator only flag;

n - no messages to channel from clients on the outside;

m - moderated channel;

l - set the user limit to channel;




Oikarinen & Reed [Page 21]

RFC 1459 Internet Relay Chat Protocol May 1993



b - set a ban mask to keep users out;

v - give/take the ability to speak on a moderated channel;

k - set a channel key (password).


When using the 'o' and 'b' options, a restriction on a total of three

per mode command has been imposed. That is, any combination of 'o'

and


4.2.3.2 User modes


Parameters: <nickname> {[+|-]|i|w|s|o}


The user MODEs are typically changes which affect either how the

client is seen by others or what 'extra' messages the client is sent.

A user MODE command may only be accepted if both the sender of the

message and the nickname given as a parameter are both the same.


The available modes are as follows:


i - marks a users as invisible;

s - marks a user for receipt of server notices;

w - user receives wallops;

o - operator flag.


Additional modes may be available later on.


If a user attempts to make themselves an operator using the "+o"

flag, the attempt should be ignored. There is no restriction,

however, on anyone `deopping' themselves (using "-o"). Numeric

Replies:


ERR_NEEDMOREPARAMS RPL_CHANNELMODEIS

ERR_CHANOPRIVSNEEDED ERR_NOSUCHNICK

ERR_NOTONCHANNEL ERR_KEYSET

RPL_BANLIST RPL_ENDOFBANLIST

ERR_UNKNOWNMODE ERR_NOSUCHCHANNEL


ERR_USERSDONTMATCH RPL_UMODEIS

ERR_UMODEUNKNOWNFLAG


Examples:


Use of Channel Modes:


MODE #Finnish +im ; Makes #Finnish channel moderated and

'invite-only'.


MODE #Finnish +o Kilroy ; Gives 'chanop' privileges to Kilroy on




Oikarinen & Reed [Page 22]

RFC 1459 Internet Relay Chat Protocol May 1993



channel #Finnish.


MODE #Finnish +v Wiz ; Allow WiZ to speak on #Finnish.


MODE #Fins -s ; Removes 'secret' flag from channel

#Fins.


MODE #42 +k oulu ; Set the channel key to "oulu".


MODE #eu-opers +l 10 ; Set the limit for the number of users

on channel to 10.


MODE &oulu +b ; list ban masks set for channel.


MODE &oulu +b *!*@* ; prevent all users from joining.


MODE &oulu +b *!*@*.edu ; prevent any user from a hostname

matching *.edu from joining.


Use of user Modes:


:MODE WiZ -w ; turns reception of WALLOPS messages

off for WiZ.


:Angel MODE Angel +i ; Message from Angel to make themselves

invisible.


MODE WiZ -o ; WiZ 'deopping' (removing operator

status). The plain reverse of this

command ("MODE WiZ +o") must not be

allowed from users since would bypass

the OPER command.


4.2.4 Topic message


Command: TOPIC

Parameters: <channel> [<topic>]


The TOPIC message is used to change or view the topic of a channel.

The topic for channel <channel> is returned if there is no <topic>

given. If the <topic> parameter is present, the topic for that

channel will be changed, if the channel modes permit this action.


Numeric Replies:


ERR_NEEDMOREPARAMS ERR_NOTONCHANNEL

RPL_NOTOPIC RPL_TOPIC

ERR_CHANOPRIVSNEEDED




Oikarinen & Reed [Page 23]

RFC 1459 Internet Relay Chat Protocol May 1993



Examples:


:Wiz TOPIC #test :New topic ;User Wiz setting the topic.


TOPIC #test :another topic ;set the topic on #test to "another

topic".


TOPIC #test ; check the topic for #test.


4.2.5 Names message


Command: NAMES

Parameters: [<channel>{,<channel>}]


By using the NAMES command, a user can list all nicknames that are

visible to them on any channel that they can see. Channel names

which they can see are those which aren't private (+p) or secret (+s)

or those which they are actually on. The <channel> parameter

specifies which channel(s) to return information about if valid.

There is no error reply for bad channel names.


If no <channel> parameter is given, a list of all channels and their

occupants is returned. At the end of this list, a list of users who

are visible but either not on any channel or not on a visible channel

are listed as being on `channel' "*".


Numerics:


RPL_NAMREPLY RPL_ENDOFNAMES


Examples:


NAMES #twilight_zone,#42 ; list visible users on #twilight_zone

and #42 if the channels are visible to

you.


NAMES ; list all visible channels and users


4.2.6 List message


Command: LIST

Parameters: [<channel>{,<channel>} [<server>]]


The list message is used to list channels and their topics. If the

<channel> parameter is used, only the status of that channel

is displayed. Private channels are listed (without their

topics) as channel "Prv" unless the client generating the query is

actually on that channel. Likewise, secret channels are not listed




Oikarinen & Reed [Page 24]

RFC 1459 Internet Relay Chat Protocol May 1993



at all unless the client is a member of the channel in question.


Numeric Replies:


ERR_NOSUCHSERVER RPL_LISTSTART

RPL_LIST RPL_LISTEND


Examples:


LIST ; List all channels.


LIST #twilight_zone,#42 ; List channels #twilight_zone and #42


4.2.7 Invite message


Command: INVITE

Parameters: <nickname> <channel>


The INVITE message is used to invite users to a channel. The

parameter <nickname> is the nickname of the person to be invited to

the target channel <channel>. There is no requirement that the

channel the target user is being invited to must exist or be a valid

channel. To invite a user to a channel which is invite only (MODE

+i), the client sending the invite must be recognised as being a

channel operator on the given channel.


Numeric Replies:


ERR_NEEDMOREPARAMS ERR_NOSUCHNICK

ERR_NOTONCHANNEL ERR_USERONCHANNEL

ERR_CHANOPRIVSNEEDED

RPL_INVITING RPL_AWAY


Examples:


:Angel INVITE Wiz #Dust ; User Angel inviting WiZ to channel

#Dust


INVITE Wiz #Twilight_Zone ; Command to invite WiZ to

#Twilight_zone


4.2.8 Kick command


Command: KICK

Parameters: <channel> <user> [<comment>]


The KICK command can be used to forcibly remove a user from a

channel. It 'kicks them out' of the channel (forced PART).




Oikarinen & Reed [Page 25]

RFC 1459 Internet Relay Chat Protocol May 1993



Only a channel operator may kick another user out of a channel.

Each server that receives a KICK message checks that it is valid

(ie the sender is actually a channel operator) before removing

the victim from the channel.


Numeric Replies:


ERR_NEEDMOREPARAMS ERR_NOSUCHCHANNEL

ERR_BADCHANMASK ERR_CHANOPRIVSNEEDED

ERR_NOTONCHANNEL


Examples:


KICK &Melbourne Matthew ; Kick Matthew from &Melbourne


KICK #Finnish John :Speaking English

; Kick John from #Finnish using

"Speaking English" as the reason

(comment).


:WiZ KICK #Finnish John ; KICK message from WiZ to remove John

from channel #Finnish


NOTE:

It is possible to extend the KICK command parameters to the

following:


<channel>{,<channel>} <user>{,<user>} [<comment>]


4.3 Server queries and commands


The server query group of commands has been designed to return

information about any server which is connected to the network. All

servers connected must respond to these queries and respond

correctly. Any invalid response (or lack thereof) must be considered

a sign of a broken server and it must be disconnected/disabled as

soon as possible until the situation is remedied.


In these queries, where a parameter appears as "<server>", it will

usually mean it can be a nickname or a server or a wildcard name of

some sort. For each parameter, however, only one query and set of

replies is to be generated.


4.3.1 Version message


Command: VERSION

Parameters: [<server>]





Oikarinen & Reed [Page 26]

RFC 1459 Internet Relay Chat Protocol May 1993



The VERSION message is used to query the version of the server

program. An optional parameter <server> is used to query the version

of the server program which a client is not directly connected to.


Numeric Replies:


ERR_NOSUCHSERVER RPL_VERSION


Examples:


:Wiz VERSION *.se ; message from Wiz to check the version

of a server matching "*.se"


VERSION tolsun.oulu.fi ; check the version of server

"tolsun.oulu.fi".


4.3.2 Stats message


Command: STATS

Parameters: [<query> [<server>]]


The stats message is used to query statistics of certain server. If

<server> parameter is omitted, only the end of stats reply is sent

back. The implementation of this command is highly dependent on the

server which replies, although the server must be able to supply

information as described by the queries below (or similar).


A query may be given by any single letter which is only checked by

the destination server (if given as the <server> parameter) and is

otherwise passed on by intermediate servers, ignored and unaltered.

The following queries are those found in the current IRC

implementation and provide a large portion of the setup information

for that server. Although these may not be supported in the same way

by other versions, all servers should be able to supply a valid reply

to a STATS query which is consistent with the reply formats currently

used and the purpose of the query.


The currently supported queries are:


c - returns a list of servers which the server may connect

to or allow connections from;

h - returns a list of servers which are either forced to be

treated as leaves or allowed to act as hubs;

i - returns a list of hosts which the server allows a client

to connect from;

k - returns a list of banned username/hostname combinations

for that server;

l - returns a list of the server's connections, showing how




Oikarinen & Reed [Page 27]

RFC 1459 Internet Relay Chat Protocol May 1993



long each connection has been established and the traffic

over that connection in bytes and messages for each

direction;

m - returns a list of commands supported by the server and

the usage count for each if the usage count is non zero;

o - returns a list of hosts from which normal clients may

become operators;

y - show Y (Class) lines from server's configuration file;

u - returns a string showing how long the server has been up.


Numeric Replies:


ERR_NOSUCHSERVER

RPL_STATSCLINE RPL_STATSNLINE

RPL_STATSILINE RPL_STATSKLINE

RPL_STATSQLINE RPL_STATSLLINE

RPL_STATSLINKINFO RPL_STATSUPTIME

RPL_STATSCOMMANDS RPL_STATSOLINE

RPL_STATSHLINE RPL_ENDOFSTATS


Examples:


STATS m ; check the command usage for the server

you are connected to


:Wiz STATS c eff.org ; request by WiZ for C/N line

information from server eff.org


4.3.3 Links message


Command: LINKS

Parameters: [[<remote server>] <server mask>]


With LINKS, a user can list all servers which are known by the server

answering the query. The returned list of servers must match the

mask, or if no mask is given, the full list is returned.


If <remote server> is given in addition to <server mask>, the LINKS

command is forwarded to the first server found that matches that name

(if any), and that server is then required to answer the query.


Numeric Replies:


ERR_NOSUCHSERVER

RPL_LINKS RPL_ENDOFLINKS


Examples:





Oikarinen & Reed [Page 28]

RFC 1459 Internet Relay Chat Protocol May 1993



LINKS *.au ; list all servers which have a name

that matches *.au;


:WiZ LINKS *.bu.edu *.edu ; LINKS message from WiZ to the first

server matching *.edu for a list of

servers matching *.bu.edu.


4.3.4 Time message


Command: TIME

Parameters: [<server>]


The time message is used to query local time from the specified

server. If the server parameter is not given, the server handling the

command must reply to the query.


Numeric Replies:


ERR_NOSUCHSERVER RPL_TIME


Examples:


TIME tolsun.oulu.fi ; check the time on the server

"tolson.oulu.fi"


Angel TIME *.au ; user angel checking the time on a

server matching "*.au"


4.3.5 Connect message


Command: CONNECT

Parameters: <target server> [<port> [<remote server>]]


The CONNECT command can be used to force a server to try to establish

a new connection to another server immediately. CONNECT is a

privileged command and is to be available only to IRC Operators. If

a remote server is given then the CONNECT attempt is made by that

server to <target server> and <port>.


Numeric Replies:


ERR_NOSUCHSERVER ERR_NOPRIVILEGES

ERR_NEEDMOREPARAMS


Examples:


CONNECT tolsun.oulu.fi ; Attempt to connect a server to

tolsun.oulu.fi




Oikarinen & Reed [Page 29]

RFC 1459 Internet Relay Chat Protocol May 1993



:WiZ CONNECT eff.org 6667 csd.bu.edu

; CONNECT attempt by WiZ to get servers

eff.org and csd.bu.edu connected on port

6667.


4.3.6 Trace message


Command: TRACE

Parameters: [<server>]


TRACE command is used to find the route to specific server. Each

server that processes this message must tell the sender about it by

sending a reply indicating it is a pass-through link, forming a chain

of replies similar to that gained from using "traceroute". After

sending this reply back, it must then send the TRACE message to the

next server until given server is reached. If the <server> parameter

is omitted, it is recommended that TRACE command send a message to

the sender telling which servers the current server has direct

connection to.


If the destination given by "<server>" is an actual server, then the

destination server is required to report all servers and users which

are connected to it, although only operators are permitted to see

users present. If the destination given by <server> is a nickname,

they only a reply for that nickname is given.


Numeric Replies:


ERR_NOSUCHSERVER


If the TRACE message is destined for another server, all intermediate

servers must return a RPL_TRACELINK reply to indicate that the TRACE

passed through it and where its going next.


RPL_TRACELINK

A TRACE reply may be composed of any number of the following numeric

replies.


RPL_TRACECONNECTING RPL_TRACEHANDSHAKE

RPL_TRACEUNKNOWN RPL_TRACEOPERATOR

RPL_TRACEUSER RPL_TRACESERVER

RPL_TRACESERVICE RPL_TRACENEWTYPE

RPL_TRACECLASS


Examples:


TRACE *.oulu.fi ; TRACE to a server matching *.oulu.fi





Oikarinen & Reed [Page 30]

RFC 1459 Internet Relay Chat Protocol May 1993



:WiZ TRACE AngelDust ; TRACE issued by WiZ to nick AngelDust


4.3.7 Admin command


Command: ADMIN

Parameters: [<server>]


The admin message is used to find the name of the administrator of

the given server, or current server if <server> parameter is omitted.

Each server must have the ability to forward ADMIN messages to other

servers.


Numeric Replies:


ERR_NOSUCHSERVER

RPL_ADMINME RPL_ADMINLOC1

RPL_ADMINLOC2 RPL_ADMINEMAIL


Examples:


ADMIN tolsun.oulu.fi ; request an ADMIN reply from

tolsun.oulu.fi


:WiZ ADMIN *.edu ; ADMIN request from WiZ for first

server found to match *.edu.


4.3.8 Info command


Command: INFO

Parameters: [<server>]


The INFO command is required to return information which describes

the server: its version, when it was compiled, the patchlevel, when

it was started, and any other miscellaneous information which may be

considered to be relevant.


Numeric Replies:


ERR_NOSUCHSERVER

RPL_INFO RPL_ENDOFINFO


Examples:


INFO csd.bu.edu ; request an INFO reply from

csd.bu.edu


:Avalon INFO *.fi ; INFO request from Avalon for first

server found to match *.fi.




Oikarinen & Reed [Page 31]

RFC 1459 Internet Relay Chat Protocol May 1993



INFO Angel ; request info from the server that

Angel is connected to.


4.4 Sending messages


The main purpose of the IRC protocol is to provide a base for clients

to communicate with each other. PRIVMSG and NOTICE are the only

messages available which actually perform delivery of a text message

from one client to another - the rest just make it possible and try

to ensure it happens in a reliable and structured manner.


4.4.1 Private messages


Command: PRIVMSG

Parameters: <receiver>{,<receiver>} <text to be sent>


PRIVMSG is used to send private messages between users. <receiver>

is the nickname of the receiver of the message. <receiver> can also

be a list of names or channels separated with commas.


The <receiver> parameter may also me a host mask (#mask) or server

mask ($mask). In both cases the server will only send the PRIVMSG

to those who have a server or host matching the mask. The mask must

have at least 1 (one) "." in it and no wildcards following the

last ".". This requirement exists to prevent people sending messages

to "#*" or "$*", which would broadcast to all users; from

experience, this is abused more than used responsibly and properly.

Wildcards are the '*' and '?' characters. This extension to

the PRIVMSG command is only available to Operators.


Numeric Replies:


ERR_NORECIPIENT ERR_NOTEXTTOSEND

ERR_CANNOTSENDTOCHAN ERR_NOTOPLEVEL

ERR_WILDTOPLEVEL ERR_TOOMANYTARGETS

ERR_NOSUCHNICK

RPL_AWAY


Examples:


:Angel PRIVMSG Wiz :Hello are you receiving this message ?

; Message from Angel to Wiz.


PRIVMSG Angel :yes I'm receiving it !receiving it !'u>(768u+1n) .br ;

Message to Angel.


PRIVMSG jto@tolsun.oulu.fi :Hello !

; Message to a client on server




Oikarinen & Reed [Page 32]

RFC 1459 Internet Relay Chat Protocol May 1993



tolsun.oulu.fi with username of "jto".


PRIVMSG $*.fi :Server tolsun.oulu.fi rebooting.

; Message to everyone on a server which

has a name matching *.fi.


PRIVMSG #*.edu :NSFNet is undergoing work, expect interruptions

; Message to all users who come from a

host which has a name matching *.edu.


4.4.2 Notice


Command: NOTICE

Parameters: <nickname> <text>


The NOTICE message is used similarly to PRIVMSG. The difference

between NOTICE and PRIVMSG is that automatic replies must never be

sent in response to a NOTICE message. This rule applies to servers

too - they must not send any error reply back to the client on

receipt of a notice. The object of this rule is to avoid loops

between a client automatically sending something in response to

something it received. This is typically used by automatons (clients

with either an AI or other interactive program controlling their

actions) which are always seen to be replying lest they end up in a

loop with another automaton.


See PRIVMSG for more details on replies and examples.


4.5 User based queries


User queries are a group of commands which are primarily concerned

with finding details on a particular user or group users. When using

wildcards with any of these commands, if they match, they will only

return information on users who are 'visible' to you. The visibility

of a user is determined as a combination of the user's mode and the

common set of channels you are both on.


4.5.1 Who query


Command: WHO

Parameters: [<name> [<o>]]


The WHO message is used by a client to generate a query which returns

a list of information which 'matches' the <name> parameter given by

the client. In the absence of the <name> parameter, all visible

(users who aren't invisible (user mode +i) and who don't have a

common channel with the requesting client) are listed. The same

result can be achieved by using a <name> of "0" or any wildcard which




Oikarinen & Reed [Page 33]

RFC 1459 Internet Relay Chat Protocol May 1993



will end up matching every entry possible.


The <name> passed to WHO is matched against users' host, server, real

name and nickname if the channel <name> cannot be found.


If the "o" parameter is passed only operators are returned according

to the name mask supplied.


Numeric Replies:


ERR_NOSUCHSERVER

RPL_WHOREPLY RPL_ENDOFWHO


Examples:


WHO *.fi ; List all users who match against

"*.fi".


WHO jto* o ; List all users with a match against

"jto*" if they are an operator.


4.5.2 Whois query


Command: WHOIS

Parameters: [<server>] <nickmask>[,<nickmask>[,...]]


This message is used to query information about particular user. The

server will answer this message with several numeric messages

indicating different statuses of each user which matches the nickmask

(if you are entitled to see them). If no wildcard is present in the

<nickmask>, any information about that nick which you are allowed to

see is presented. A comma (',') separated list of nicknames may be

given.


The latter version sends the query to a specific server. It is

useful if you want to know how long the user in question has been

idle as only local server (ie. the server the user is directly

connected to) knows that information, while everything else is

globally known.


Numeric Replies:


ERR_NOSUCHSERVER ERR_NONICKNAMEGIVEN

RPL_WHOISUSER RPL_WHOISCHANNELS

RPL_WHOISCHANNELS RPL_WHOISSERVER

RPL_AWAY RPL_WHOISOPERATOR

RPL_WHOISIDLE ERR_NOSUCHNICK

RPL_ENDOFWHOIS




Oikarinen & Reed [Page 34]

RFC 1459 Internet Relay Chat Protocol May 1993



Examples:


WHOIS wiz ; return available user information

about nick WiZ


WHOIS eff.org trillian ; ask server eff.org for user

information about trillian


4.5.3 Whowas


Command: WHOWAS

Parameters: <nickname> [<count> [<server>]]


Whowas asks for information about a nickname which no longer exists.

This may either be due to a nickname change or the user leaving IRC.

In response to this query, the server searches through its nickname

history, looking for any nicks which are lexically the same (no wild

card matching here). The history is searched backward, returning the

most recent entry first. If there are multiple entries, up to

<count> replies will be returned (or all of them if no <count>

parameter is given). If a non-positive number is passed as being

<count>, then a full search is done.


Numeric Replies:


ERR_NONICKNAMEGIVEN ERR_WASNOSUCHNICK

RPL_WHOWASUSER RPL_WHOISSERVER

RPL_ENDOFWHOWAS


Examples:


WHOWAS Wiz ; return all information in the nick

history about nick "WiZ";


WHOWAS Mermaid 9 ; return at most, the 9 most recent

entries in the nick history for

"Mermaid";


WHOWAS Trillian 1 *.edu ; return the most recent history for

"Trillian" from the first server found

to match "*.edu".


4.6 Miscellaneous messages


Messages in this category do not fit into any of the above categories

but are nonetheless still a part of and required by the protocol.






Oikarinen & Reed [Page 35]

RFC 1459 Internet Relay Chat Protocol May 1993



4.6.1 Kill message


Command: KILL

Parameters: <nickname> <comment>


The KILL message is used to cause a client-server connection to be

closed by the server which has the actual connection. KILL is used

by servers when they encounter a duplicate entry in the list of valid

nicknames and is used to remove both entries. It is also available

to operators.


Clients which have automatic reconnect algorithms effectively make

this command useless since the disconnection is only brief. It does

however break the flow of data and can be used to stop large amounts

of being abused, any user may elect to receive KILL messages

generated for others to keep an 'eye' on would be trouble spots.


In an arena where nicknames are required to be globally unique at all

times, KILL messages are sent whenever 'duplicates' are detected

(that is an attempt to register two users with the same nickname) in

the hope that both of them will disappear and only 1 reappear.


The comment given must reflect the actual reason for the KILL. For

server-generated KILLs it usually is made up of details concerning

the origins of the two conflicting nicknames. For users it is left

up to them to provide an adequate reason to satisfy others who see

it. To prevent/discourage fake KILLs from being generated to hide

the identify of the KILLer, the comment also shows a 'kill-path'

which is updated by each server it passes through, each prepending

its name to the path.


Numeric Replies:


ERR_NOPRIVILEGES ERR_NEEDMOREPARAMS

ERR_NOSUCHNICK ERR_CANTKILLSERVER



KILL David (csd.bu.edu <- tolsun.oulu.fi)

; Nickname collision between csd.bu.edu

and tolson.oulu.fi



NOTE:

It is recommended that only Operators be allowed to kill other users

with KILL message. In an ideal world not even operators would need

to do this and it would be left to servers to deal with.






Oikarinen & Reed [Page 36]

RFC 1459 Internet Relay Chat Protocol May 1993



4.6.2 Ping message


Command: PING

Parameters: <server1> [<server2>]


The PING message is used to test the presence of an active client at

the other end of the connection. A PING message is sent at regular

intervals if no other activity detected coming from a connection. If

a connection fails to respond to a PING command within a set amount

of time, that connection is closed.


Any client which receives a PING message must respond to <server1>

(server which sent the PING message out) as quickly as possible with

an appropriate PONG message to indicate it is still there and alive.

Servers should not respond to PING commands but rely on PINGs from

the other end of the connection to indicate the connection is alive.

If the <server2> parameter is specified, the PING message gets

forwarded there.


Numeric Replies:


ERR_NOORIGIN ERR_NOSUCHSERVER


Examples:


PING tolsun.oulu.fi ; server sending a PING message to

another server to indicate it is still

alive.


PING WiZ ; PING message being sent to nick WiZ


4.6.3 Pong message


Command: PONG

Parameters: <daemon> [<daemon2>]


PONG message is a reply to ping message. If parameter <daemon2> is

given this message must be forwarded to given daemon. The <daemon>

parameter is the name of the daemon who has responded to PING message

and generated this message.


Numeric Replies:


ERR_NOORIGIN ERR_NOSUCHSERVER


Examples:


PONG csd.bu.edu tolsun.oulu.fi ; PONG message from csd.bu.edu to




Oikarinen & Reed [Page 37]

RFC 1459 Internet Relay Chat Protocol May 1993



tolsun.oulu.fi


4.6.4 Error


Command: ERROR

Parameters: <error message>


The ERROR command is for use by servers when reporting a serious or

fatal error to its operators. It may also be sent from one server to

another but must not be accepted from any normal unknown clients.


An ERROR message is for use for reporting errors which occur with a

server-to-server link only. An ERROR message is sent to the server

at the other end (which sends it to all of its connected operators)

and to all operators currently connected. It is not to be passed

onto any other servers by a server if it is received from a server.


When a server sends a received ERROR message to its operators, the

message should be encapsulated inside a NOTICE message, indicating

that the client was not responsible for the error.


Numerics:


None.


Examples:


ERROR :Server *.fi already exists; ERROR message to the other server

which caused this error.


NOTICE WiZ :ERROR from csd.bu.edu -- Server *.fi already exists

; Same ERROR message as above but sent

to user WiZ on the other server.


5. OPTIONALS


This section describes OPTIONAL messages. They are not required in a

working server implementation of the protocol described herein. In

the absence of the option, an error reply message must be generated

or an unknown command error. If the message is destined for another

server to answer then it must be passed on (elementary parsing

required) The allocated numerics for this are listed with the

messages below.


5.1 Away


Command: AWAY

Parameters: [message]




Oikarinen & Reed [Page 38]

RFC 1459 Internet Relay Chat Protocol May 1993



With the AWAY message, clients can set an automatic reply string for

any PRIVMSG commands directed at them (not to a channel they are on).

The automatic reply is sent by the server to client sending the

PRIVMSG command. The only replying server is the one to which the

sending client is connected to.


The AWAY message is used either with one parameter (to set an AWAY

message) or with no parameters (to remove the AWAY message).


Numeric Replies:


RPL_UNAWAY RPL_NOWAWAY


Examples:


AWAY :Gone to lunch. Back in 5 ; set away message to "Gone to lunch.

Back in 5".


:WiZ AWAY ; unmark WiZ as being away.



5.2 Rehash message


Command: REHASH

Parameters: None


The rehash message can be used by the operator to force the server to

re-read and process its configuration file.


Numeric Replies:


RPL_REHASHING ERR_NOPRIVILEGES


Examples:


REHASH ; message from client with operator

status to server asking it to reread its

configuration file.


5.3 Restart message


Command: RESTART

Parameters: None


The restart message can only be used by an operator to force a server

restart itself. This message is optional since it may be viewed as a

risk to allow arbitrary people to connect to a server as an operator

and execute this command, causing (at least) a disruption to service.




Oikarinen & Reed [Page 39]

RFC 1459 Internet Relay Chat Protocol May 1993



The RESTART command must always be fully processed by the server to

which the sending client is connected and not be passed onto other

connected servers.


Numeric Replies:


ERR_NOPRIVILEGES


Examples:


RESTART ; no parameters required.