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Internet Relay Chat: Client Protocol.
C. Kalt. April 2000.

 
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Network Working Group C. Kalt Request for Comments: 2812 April 2000 Updates: 1459 Category: Informational Internet Relay Chat: Client Protocol Status of this Memo This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2000). All Rights Reserved. IESG NOTE: The IRC protocol itself enables several possibilities of transferring data between clients, and just like with other transfer mechanisms like email, the receiver of the data has to be careful about how the data is handled. For more information on security issues with the IRC protocol, see for example http://www.irchelp.org/irchelp/security/. Abstract The IRC (Internet Relay Chat) protocol is for use with text based conferencing; the simplest client being any socket program capable of connecting to the server. This document defines the Client Protocol, and assumes that the reader is familiar with the IRC Architecture [IRC-ARCH]. Table of Contents 1. Labels ..................................................... 3 1.1 Servers ................................................ 3 1.2 Clients ................................................ 3 1.2.1 Users ............................................. 4 1.2.1.1 Operators .................................... 4 1.2.2 Services .......................................... 4 1.3 Channels ............................................... 4 2. The IRC Client Specification ............................... 5 2.1 Overview ............................................... 5 2.2 Character codes ........................................ 5 2.3 Messages ............................................... 5 Kalt Informational [Page 1]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 2.3.1 Message format in Augmented BNF ................... 6 2.4 Numeric replies ........................................ 8 2.5 Wildcard expressions ................................... 9 3. Message Details ............................................ 9 3.1 Connection Registration ................................ 10 3.1.1 Password message .................................. 10 3.1.2 Nick message ...................................... 10 3.1.3 User message ...................................... 11 3.1.4 Oper message ...................................... 12 3.1.5 User mode message ................................. 12 3.1.6 Service message ................................... 13 3.1.7 Quit .............................................. 14 3.1.8 Squit ............................................. 15 3.2 Channel operations ..................................... 15 3.2.1 Join message ...................................... 16 3.2.2 Part message ...................................... 17 3.2.3 Channel mode message .............................. 18 3.2.4 Topic message ..................................... 19 3.2.5 Names message ..................................... 20 3.2.6 List message ...................................... 21 3.2.7 Invite message .................................... 21 3.2.8 Kick command ...................................... 22 3.3 Sending messages ....................................... 23 3.3.1 Private messages .................................. 23 3.3.2 Notice ............................................ 24 3.4 Server queries and commands ............................ 25 3.4.1 Motd message ...................................... 25 3.4.2 Lusers message .................................... 25 3.4.3 Version message ................................... 26 3.4.4 Stats message ..................................... 26 3.4.5 Links message ..................................... 27 3.4.6 Time message ...................................... 28 3.4.7 Connect message ................................... 28 3.4.8 Trace message ..................................... 29 3.4.9 Admin command ..................................... 30 3.4.10 Info command ...................................... 31 3.5 Service Query and Commands ............................. 31 3.5.1 Servlist message .................................. 31 3.5.2 Squery ............................................ 32 3.6 User based queries ..................................... 32 3.6.1 Who query ......................................... 32 3.6.2 Whois query ....................................... 33 3.6.3 Whowas ............................................ 34 3.7 Miscellaneous messages ................................. 34 3.7.1 Kill message ...................................... 35 3.7.2 Ping message ...................................... 36 3.7.3 Pong message ...................................... 37 3.7.4 Error ............................................. 37 Kalt Informational [Page 2]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 4. Optional features .......................................... 38 4.1 Away ................................................... 38 4.2 Rehash message ......................................... 39 4.3 Die message ............................................ 39 4.4 Restart message ........................................ 40 4.5 Summon message ......................................... 40 4.6 Users .................................................. 41 4.7 Operwall message ....................................... 41 4.8 Userhost message ....................................... 42 4.9 Ison message ........................................... 42 5. Replies .................................................... 43 5.1 Command responses ...................................... 43 5.2 Error Replies .......................................... 53 5.3 Reserved numerics ...................................... 59 6. Current implementations .................................... 60 7. Current problems ........................................... 60 7.1 Nicknames .............................................. 60 7.2 Limitation of wildcards ................................ 61 7.3 Security considerations ................................ 61 8. Current support and availability ........................... 61 9. Acknowledgements ........................................... 61 10. References ................................................ 62 11. Author's Address .......................................... 62 12. Full Copyright Statement .................................. 63 1. Labels This section defines the identifiers used for the various components of the IRC protocol. 1.1 Servers Servers are uniquely identified by their name, which has a maximum length of sixty three (63) characters. See the protocol grammar rules (section 2.3.1) for what may and may not be used in a server name. 1.2 Clients For each client all servers MUST have the following information: a netwide unique identifier (whose format depends on the type of client) and the server which introduced the client. Kalt Informational [Page 3]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 1.2.1 Users Each user is distinguished from other users by a unique nickname having a maximum length of nine (9) characters. See the protocol grammar rules (section 2.3.1) for what may and may not be used in a nickname. While the maximum length is limited to nine characters, clients SHOULD accept longer strings as they may become used in future evolutions of the protocol. 1.2.1.1 Operators To allow a reasonable amount of order to be kept within the IRC network, a special class of users (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 often necessary. Operators SHOULD be able to perform basic network tasks such as disconnecting and reconnecting servers as needed. In recognition of this need, the protocol discussed herein provides for operators only to be able to perform such functions. See sections 3.1.8 (SQUIT) and 3.4.7 (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 very delicate since its abuse is both destructive and annoying, and its benefits close to inexistent. For further details on this type of action, see section 3.7.1 (KILL). 1.2.2 Services Each service is distinguished from other services by a service name composed of a nickname and a server name. As for users, the nickname has a maximum length of nine (9) characters. See the protocol grammar rules (section 2.3.1) for what may and may not be used in a nickname. 1.3 Channels Channels names are strings (beginning with a '&', '#', '+' or '!' character) of length up to fifty (50) characters. Apart from the requirement that the first character is either '&', '#', '+' or '!', the only restriction on a channel name is that it SHALL NOT contain any spaces (' '), a control G (^G or ASCII 7), a comma (','). Space is used as parameter separator and command is used as a list item separator by the protocol). A colon (':') can also be used as a delimiter for the channel mask. Channel names are case insensitive. Kalt Informational [Page 4]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 See the protocol grammar rules (section 2.3.1) for the exact syntax of a channel name. Each prefix characterizes a different channel type. The definition of the channel types is not relevant to the client-server protocol and thus it is beyond the scope of this document. More details can be found in "Internet Relay Chat: Channel Management" [IRC-CHAN]. 2. The IRC Client Specification 2.1 Overview The protocol as described herein is for use only with client to server connections when the client registers as a user. 2.2 Character codes No specific character set is specified. The protocol is based on 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 US-ASCII terminal and a telnet connection. Because of IRC's Scandinavian 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 or channel names. 2.3 Messages Servers and clients send each other 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 by nature. Each IRC message may consist of up to three main parts: the prefix (OPTIONAL), the command, and the command parameters (maximum of fifteen (15)). The prefix, command, and all parameters are separated by one ASCII space character (0x20) each. Kalt Informational [Page 5]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 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 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 from. Clients SHOULD NOT use a prefix when sending a message; if they use one, the only valid prefix is the registered nickname associated with the client. 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 of message lines. See section 6 for more details about current implementations. 2.3.1 Message format in Augmented 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 (<params>). The Augmented BNF representation for this is: message = [ ":" prefix SPACE ] command [ params ] crlf prefix = servername / ( nickname [ [ "!" user ] "@" host ] ) command = 1*letter / 3digit params = *14( SPACE middle ) [ SPACE ":" trailing ] =/ 14( SPACE middle ) [ SPACE [ ":" ] trailing ] nospcrlfcl = %x01-09 / %x0B-0C / %x0E-1F / %x21-39 / %x3B-FF ; any octet except NUL, CR, LF, " " and ":" middle = nospcrlfcl *( ":" / nospcrlfcl ) trailing = *( ":" / " " / nospcrlfcl ) SPACE = %x20 ; space character crlf = %x0D %x0A ; "carriage return" "linefeed" Kalt Informational [Page 6]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 NOTES: 1) 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 the parameter. 2) The NUL (%x00) character is not special in message framing, and basically could end up inside a parameter, but it would cause extra complexities in normal C string handling. Therefore, NUL is not allowed within messages. 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 = nickname / server msgtarget = msgto *( "," msgto ) msgto = channel / ( user [ "%" host ] "@" servername ) msgto =/ ( user "%" host ) / targetmask msgto =/ nickname / ( nickname "!" user "@" host ) channel = ( "#" / "+" / ( "!" channelid ) / "&" ) chanstring [ ":" chanstring ] servername = hostname host = hostname / hostaddr hostname = shortname *( "." shortname ) shortname = ( letter / digit ) *( letter / digit / "-" ) *( letter / digit ) ; as specified in RFC 1123 [HNAME] hostaddr = ip4addr / ip6addr ip4addr = 1*3digit "." 1*3digit "." 1*3digit "." 1*3digit ip6addr = 1*hexdigit 7( ":" 1*hexdigit ) ip6addr =/ "0:0:0:0:0:" ( "0" / "FFFF" ) ":" ip4addr nickname = ( letter / special ) *8( letter / digit / special / "-" ) targetmask = ( "$" / "#" ) mask ; see details on allowed masks in section 3.3.1 chanstring = %x01-07 / %x08-09 / %x0B-0C / %x0E-1F / %x21-2B chanstring =/ %x2D-39 / %x3B-FF ; any octet except NUL, BELL, CR, LF, " ", "," and ":" channelid = 5( %x41-5A / digit ) ; 5( A-Z / 0-9 ) Kalt Informational [Page 7]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 Other parameter syntaxes are: user = 1*( %x01-09 / %x0B-0C / %x0E-1F / %x21-3F / %x41-FF ) ; any octet except NUL, CR, LF, " " and "@" key = 1*23( %x01-05 / %x07-08 / %x0C / %x0E-1F / %x21-7F ) ; any 7-bit US_ASCII character, ; except NUL, CR, LF, FF, h/v TABs, and " " letter = %x41-5A / %x61-7A ; A-Z / a-z digit = %x30-39 ; 0-9 hexdigit = digit / "A" / "B" / "C" / "D" / "E" / "F" special = %x5B-60 / %x7B-7D ; "[", "]", "\", "`", "_", "^", "{", "|", "}" NOTES: 1) The <hostaddr> syntax is given here for the sole purpose of indicating the format to follow for IP addresses. This reflects the fact that the only available implementations of this protocol uses TCP/IP as underlying network protocol but is not meant to prevent other protocols to be used. 2) <hostname> has a maximum length of 63 characters. This is a limitation of the protocol as internet hostnames (in particular) can be longer. Such restriction is necessary because IRC messages are limited to 512 characters in length. Clients connecting from a host which name is longer than 63 characters are registered using the host (numeric) address instead of the host name. 3) Some parameters used in the following sections of this documents are not defined here as there is nothing specific about them besides the name that is used for convenience. These parameters follow the general syntax defined for <params>. 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. 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 5 (Replies). Kalt Informational [Page 8]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 2.5 Wildcard expressions When wildcards are allowed in a string, it is referred as a "mask". For string matching purposes, the protocol allows the use of two special characters: '?' (%x3F) to match one and only one character, and '*' (%x2A) to match any number of any characters. These two characters can be escaped using the character '\' (%x5C). The Augmented BNF syntax for this is: mask = *( nowild / noesc wildone / noesc wildmany ) wildone = %x3F wildmany = %x2A nowild = %x01-29 / %x2B-3E / %x40-FF ; any octet except NUL, "*", "?" noesc = %x01-5B / %x5D-FF ; any octet except NUL and "\" matchone = %x01-FF ; matches wildone matchmany = *matchone ; matches wildmany Examples: a?c ; Matches any string of 3 characters in length starting with "a" and ending with "c" a*c ; Matches any string of at least 2 characters in length starting with "a" and ending with "c" 3. Message Details On the following pages there 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 returned, it means that the target of the message could not be found. The server MUST NOT send any other replies after this error for that command. The server to which a client is connected is required to parse the complete message, and return any appropriate errors. If multiple parameters is presented, then each MUST be checked for validity and appropriate responses MUST be sent back to the client. In the case of incorrect messages which use parameter lists with comma as an item separator, a reply MUST be sent for each item. Kalt Informational [Page 9]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 3.1 Connection Registration The commands described here are used to register a connection with an IRC server as a user as well as to correctly disconnect. A "PASS" command is not required for a client connection to be registered, but it MUST precede the latter of the NICK/USER combination (for a user connection) or the SERVICE command (for a service connection). The RECOMMENDED order for a client to register is as follows: 1. Pass message 2. Nick message 2. Service message 3. User message Upon success, the client will receive an RPL_WELCOME (for users) or RPL_YOURESERVICE (for services) message indicating that the connection is now registered and known the to the entire IRC network. The reply message MUST contain the full client identifier upon which it was registered. 3.1.1 Password message Command: PASS Parameters: <password> The PASS command is used to set a 'connection password'. The optional password can and MUST be set before any attempt to register the connection is made. Currently this requires that user send a PASS command before sending the NICK/USER combination. Numeric Replies: ERR_NEEDMOREPARAMS ERR_ALREADYREGISTRED Example: PASS secretpasswordhere 3.1.2 Nick message Command: NICK Parameters: <nickname> NICK command is used to give user a nickname or change the existing one. Kalt Informational [Page 10]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 Numeric Replies: ERR_NONICKNAMEGIVEN ERR_ERRONEUSNICKNAME ERR_NICKNAMEINUSE ERR_NICKCOLLISION ERR_UNAVAILRESOURCE ERR_RESTRICTED Examples: NICK Wiz ; Introducing new nick "Wiz" if session is still unregistered, or user changing his nickname to "Wiz" :WiZ!jto@tolsun.oulu.fi NICK Kilroy ; Server telling that WiZ changed his nickname to Kilroy. 3.1.3 User message Command: USER Parameters: <user> <mode> <unused> <realname> The USER command is used at the beginning of connection to specify the username, hostname and realname of a new user. The <mode> parameter should be a numeric, and can be used to automatically set user modes when registering with the server. This parameter is a bitmask, with only 2 bits having any signification: if the bit 2 is set, the user mode 'w' will be set and if the bit 3 is set, the user mode 'i' will be set. (See Section 3.1.5 "User Modes"). The <realname> may contain space characters. Numeric Replies: ERR_NEEDMOREPARAMS ERR_ALREADYREGISTRED Example: USER guest 0 * :Ronnie Reagan ; User registering themselves with a username of "guest" and real name "Ronnie Reagan". USER guest 8 * :Ronnie Reagan ; User registering themselves with a username of "guest" and real name "Ronnie Reagan", and asking to be set invisible. Kalt Informational [Page 11]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 3.1.4 Oper message Command: OPER Parameters: <name> <password> A normal user uses the OPER command to obtain operator privileges. The combination of <name> and <password> are REQUIRED to gain Operator privileges. Upon success, the user will receive a MODE message (see section 3.1.5) indicating the new user modes. 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. 3.1.5 User mode message Command: MODE Parameters: <nickname> *( ( "+" / "-" ) *( "i" / "w" / "o" / "O" / "r" ) ) The user MODE's 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 MUST only be accepted if both the sender of the message and the nickname given as a parameter are both the same. If no other parameter is given, then the server will return the current settings for the nick. The available modes are as follows: a - user is flagged as away; i - marks a users as invisible; w - user receives wallops; r - restricted user connection; o - operator flag; O - local operator flag; s - marks a user for receipt of server notices. Additional modes may be available later on. Kalt Informational [Page 12]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 The flag 'a' SHALL NOT be toggled by the user using the MODE command, instead use of the AWAY command is REQUIRED. If a user attempts to make themselves an operator using the "+o" or "+O" flag, the attempt SHOULD be ignored as users could bypass the authentication mechanisms of the OPER command. There is no restriction, however, on anyone `deopping' themselves (using "-o" or "-O"). On the other hand, if a user attempts to make themselves unrestricted using the "-r" flag, the attempt SHOULD be ignored. There is no restriction, however, on anyone `deopping' themselves (using "+r"). This flag is typically set by the server upon connection for administrative reasons. While the restrictions imposed are left up to the implementation, it is typical that a restricted user not be allowed to change nicknames, nor make use of the channel operator status on channels. The flag 's' is obsolete but MAY still be used. Numeric Replies: ERR_NEEDMOREPARAMS ERR_USERSDONTMATCH ERR_UMODEUNKNOWNFLAG RPL_UMODEIS Examples: MODE WiZ -w ; Command by WiZ to turn off reception of WALLOPS messages. MODE Angel +i ; Command from Angel to make herself invisible. MODE WiZ -o ; WiZ 'deopping' (removing operator status). 3.1.6 Service message Command: SERVICE Parameters: <nickname> <reserved> <distribution> <type> <reserved> <info> The SERVICE command to register a new service. Command parameters specify the service nickname, distribution, type and info of a new service. Kalt Informational [Page 13]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 The <distribution> parameter is used to specify the visibility of a service. The service may only be known to servers which have a name matching the distribution. For a matching server to have knowledge of the service, the network path between that server and the server on which the service is connected MUST be composed of servers which names all match the mask. The <type> parameter is currently reserved for future usage. Numeric Replies: ERR_ALREADYREGISTRED ERR_NEEDMOREPARAMS ERR_ERRONEUSNICKNAME RPL_YOURESERVICE RPL_YOURHOST RPL_MYINFO Example: SERVICE dict * *.fr 0 0 :French Dictionary ; Service registering itself with a name of "dict". This service will only be available on servers which name matches "*.fr". 3.1.7 Quit Command: QUIT Parameters: [ <Quit Message> ] A client session is terminated with a quit message. The server acknowledges this by sending an ERROR message to the client. Numeric Replies: None. Example: QUIT :Gone to have lunch ; Preferred message format. :syrk!kalt@millennium.stealth.net QUIT :Gone to have lunch ; User syrk has quit IRC to have lunch. Kalt Informational [Page 14]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 3.1.8 Squit Command: SQUIT Parameters: <server> <comment> The SQUIT command is available only to operators. It is used to disconnect server links. Also servers can generate SQUIT messages on error conditions. A SQUIT message may also target a remote server connection. In this case, the SQUIT message will simply be sent to the remote server without affecting the servers in between the operator and the remote server. The <comment> SHOULD be supplied by all operators who execute a SQUIT for a remote server. The server ordered to disconnect its peer generates a WALLOPS message with <comment> included, so that other users may be aware of the reason of this action. Numeric replies: ERR_NOPRIVILEGES ERR_NOSUCHSERVER ERR_NEEDMOREPARAMS Examples: SQUIT tolsun.oulu.fi :Bad Link ? ; Command to uplink of the server tolson.oulu.fi to terminate its connection with comment "Bad Link". :Trillian SQUIT cm22.eng.umd.edu :Server out of control ; Command from Trillian from to disconnect "cm22.eng.umd.edu" from the net with comment "Server out of control". 3.2 Channel operations This group of messages is concerned with manipulating channels, their properties (channel modes), and their contents (typically users). For this reason, these messages SHALL NOT be made available to services. All of these messages are requests which will or will not be granted by the server. The server MUST send a reply informing the user whether the request was granted, denied or generated an error. When the server grants the request, the message is typically sent back (eventually reformatted) to the user with the prefix set to the user itself. Kalt Informational [Page 15]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 The rules governing how channels are managed are enforced by the servers. These rules are beyond the scope of this document. More details are found in "Internet Relay Chat: Channel Management" [IRC- CHAN]. 3.2.1 Join message Command: JOIN Parameters: ( <channel> *( "," <channel> ) [ <key> *( "," <key> ) ] ) / "0" The JOIN command is used by a user to request to start listening to the specific channel. Servers MUST be able to parse arguments in the form of a list of target, but SHOULD NOT use lists when sending JOIN messages to clients. Once a user has joined a channel, he receives information about all commands his server receives affecting the channel. This includes JOIN, MODE, KICK, PART, QUIT and of course PRIVMSG/NOTICE. This allows channel members to keep track of the other channel members, as well as channel modes. If a JOIN is successful, the user receives a JOIN message as confirmation and 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. Note that this message accepts a special argument ("0"), which is a special request to leave all channels the user is currently a member of. The server will process this message as if the user had sent a PART command (See Section 3.2.2) for each channel he is a member of. Numeric Replies: ERR_NEEDMOREPARAMS ERR_BANNEDFROMCHAN ERR_INVITEONLYCHAN ERR_BADCHANNELKEY ERR_CHANNELISFULL ERR_BADCHANMASK ERR_NOSUCHCHANNEL ERR_TOOMANYCHANNELS ERR_TOOMANYTARGETS ERR_UNAVAILRESOURCE RPL_TOPIC Examples: JOIN #foobar ; Command to join channel #foobar. JOIN &foo fubar ; Command to join channel &foo using key "fubar". Kalt Informational [Page 16]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 JOIN #foo,&bar fubar ; Command to join channel #foo using key "fubar" and &bar using no key. JOIN #foo,#bar fubar,foobar ; Command to join channel #foo using key "fubar", and channel #bar using key "foobar". JOIN #foo,#bar ; Command to join channels #foo and #bar. JOIN 0 ; Leave all currently joined channels. :WiZ!jto@tolsun.oulu.fi JOIN #Twilight_zone ; JOIN message from WiZ on channel #Twilight_zone 3.2.2 Part message Command: PART Parameters: <channel> *( "," <channel> ) [ <Part Message> ] The PART command causes the user sending the message to be removed from the list of active members for all given channels listed in the parameter string. If a "Part Message" is given, this will be sent instead of the default message, the nickname. This request is always granted by the server. Servers MUST be able to parse arguments in the form of a list of target, but SHOULD NOT use lists when sending PART messages to clients. Numeric Replies: ERR_NEEDMOREPARAMS ERR_NOSUCHCHANNEL ERR_NOTONCHANNEL Examples: PART #twilight_zone ; Command to leave channel "#twilight_zone" PART #oz-ops,&group5 ; Command to leave both channels "&group5" and "#oz-ops". :WiZ!jto@tolsun.oulu.fi PART #playzone :I lost ; User WiZ leaving channel "#playzone" with the message "I lost". Kalt Informational [Page 17]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 3.2.3 Channel mode message Command: MODE Parameters: <channel> *( ( "-" / "+" ) *<modes> *<modeparams> ) The MODE command is provided so that users may query and change the characteristics of a channel. For more details on available modes and their uses, see "Internet Relay Chat: Channel Management" [IRC- CHAN]. Note that there is a maximum limit of three (3) changes per command for modes that take a parameter. Numeric Replies: ERR_NEEDMOREPARAMS ERR_KEYSET ERR_NOCHANMODES ERR_CHANOPRIVSNEEDED ERR_USERNOTINCHANNEL ERR_UNKNOWNMODE RPL_CHANNELMODEIS RPL_BANLIST RPL_ENDOFBANLIST RPL_EXCEPTLIST RPL_ENDOFEXCEPTLIST RPL_INVITELIST RPL_ENDOFINVITELIST RPL_UNIQOPIS The following examples are given to help understanding the syntax of the MODE command, but refer to modes defined in "Internet Relay Chat: Channel Management" [IRC-CHAN]. Examples: MODE #Finnish +imI *!*@*.fi ; Command to make #Finnish channel moderated and 'invite-only' with user with a hostname matching *.fi automatically invited. MODE #Finnish +o Kilroy ; Command to give 'chanop' privileges to Kilroy on channel #Finnish. MODE #Finnish +v Wiz ; Command to allow WiZ to speak on #Finnish. MODE #Fins -s ; Command to remove 'secret' flag from channel #Fins. MODE #42 +k oulu ; Command to set the channel key to "oulu". MODE #42 -k oulu ; Command to remove the "oulu" channel key on channel "#42". Kalt Informational [Page 18]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 MODE #eu-opers +l 10 ; Command to set the limit for the number of users on channel "#eu-opers" to 10. :WiZ!jto@tolsun.oulu.fi MODE #eu-opers -l ; User "WiZ" removing the limit for the number of users on channel "#eu- opers". MODE &oulu +b ; Command to list ban masks set for the channel "&oulu". MODE &oulu +b *!*@* ; Command to prevent all users from joining. MODE &oulu +b *!*@*.edu +e *!*@*.bu.edu ; Command to prevent any user from a hostname matching *.edu from joining, except if matching *.bu.edu MODE #bu +be *!*@*.edu *!*@*.bu.edu ; Comment to prevent any user from a hostname matching *.edu from joining, except if matching *.bu.edu MODE #meditation e ; Command to list exception masks set for the channel "#meditation". MODE #meditation I ; Command to list invitations masks set for the channel "#meditation". MODE !12345ircd O ; Command to ask who the channel creator for "!12345ircd" is 3.2.4 Topic message Command: TOPIC Parameters: <channel> [ <topic> ] The TOPIC command 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 this action is allowed for the user requesting it. If the <topic> parameter is an empty string, the topic for that channel will be removed. Kalt Informational [Page 19]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 Numeric Replies: ERR_NEEDMOREPARAMS ERR_NOTONCHANNEL RPL_NOTOPIC RPL_TOPIC ERR_CHANOPRIVSNEEDED ERR_NOCHANMODES Examples: :WiZ!jto@tolsun.oulu.fi TOPIC #test :New topic ; User Wiz setting the topic. TOPIC #test :another topic ; Command to set the topic on #test to "another topic". TOPIC #test : ; Command to clear the topic on #test. TOPIC #test ; Command to check the topic for #test. 3.2.5 Names message Command: NAMES Parameters: [ <channel> *( "," <channel> ) [ <target> ] ] By using the NAMES command, a user can list all nicknames that are visible to him. For more details on what is visible and what is not, see "Internet Relay Chat: Channel Management" [IRC-CHAN]. The <channel> parameter specifies which channel(s) to return information about. 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' "*". If the <target> parameter is specified, the request is forwarded to that server which will generate the reply. Wildcards are allowed in the <target> parameter. Numerics: ERR_TOOMANYMATCHES ERR_NOSUCHSERVER RPL_NAMREPLY RPL_ENDOFNAMES Kalt Informational [Page 20]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 Examples: NAMES #twilight_zone,#42 ; Command to list visible users on #twilight_zone and #42 NAMES ; Command to list all visible channels and users 3.2.6 List message Command: LIST Parameters: [ <channel> *( "," <channel> ) [ <target> ] ] The list command is used to list channels and their topics. If the <channel> parameter is used, only the status of that channel is displayed. If the <target> parameter is specified, the request is forwarded to that server which will generate the reply. Wildcards are allowed in the <target> parameter. Numeric Replies: ERR_TOOMANYMATCHES ERR_NOSUCHSERVER RPL_LIST RPL_LISTEND Examples: LIST ; Command to list all channels. LIST #twilight_zone,#42 ; Command to list channels #twilight_zone and #42 3.2.7 Invite message Command: INVITE Parameters: <nickname> <channel> The INVITE command is used to invite a user 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. However, if the channel exists, only members of the channel are allowed to invite other users. When the channel has invite-only flag set, only channel operators may issue INVITE command. Kalt Informational [Page 21]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 Only the user inviting and the user being invited will receive notification of the invitation. Other channel members are not notified. (This is unlike the MODE changes, and is occasionally the source of trouble for users.) Numeric Replies: ERR_NEEDMOREPARAMS ERR_NOSUCHNICK ERR_NOTONCHANNEL ERR_USERONCHANNEL ERR_CHANOPRIVSNEEDED RPL_INVITING RPL_AWAY Examples: :Angel!wings@irc.org INVITE Wiz #Dust ; Message to WiZ when he has been invited by user Angel to channel #Dust INVITE Wiz #Twilight_Zone ; Command to invite WiZ to #Twilight_zone 3.2.8 Kick command Command: KICK Parameters: <channel> *( "," <channel> ) <user> *( "," <user> ) [<comment>] The KICK command can be used to request the forced removal of a user from a channel. It causes the <user> to PART from the <channel> by force. For the message to be syntactically correct, there MUST be either one channel parameter and multiple user parameter, or as many channel parameters as there are user parameters. If a "comment" is given, this will be sent instead of the default message, the nickname of the user issuing the KICK. The server MUST NOT send KICK messages with multiple channels or users to clients. This is necessarily to maintain backward compatibility with old client software. Numeric Replies: ERR_NEEDMOREPARAMS ERR_NOSUCHCHANNEL ERR_BADCHANMASK ERR_CHANOPRIVSNEEDED ERR_USERNOTINCHANNEL ERR_NOTONCHANNEL Kalt Informational [Page 22]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 Examples: KICK &Melbourne Matthew ; Command to kick Matthew from &Melbourne KICK #Finnish John :Speaking English ; Command to kick John from #Finnish using "Speaking English" as the reason (comment). :WiZ!jto@tolsun.oulu.fi KICK #Finnish John ; KICK message on channel #Finnish from WiZ to remove John from channel 3.3 Sending messages The main purpose of the IRC protocol is to provide a base for clients to communicate with each other. PRIVMSG, NOTICE and SQUERY (described in Section 3.5 on Service Query and Commands) 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. 3.3.1 Private messages Command: PRIVMSG Parameters: <msgtarget> <text to be sent> PRIVMSG is used to send private messages between users, as well as to send messages to channels. <msgtarget> is usually the nickname of the recipient of the message, or a channel name. The <msgtarget> parameter may also be 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. 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 Kalt Informational [Page 23]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 Examples: :Angel!wings@irc.org PRIVMSG Wiz :Are you receiving this message ? ; Message from Angel to Wiz. PRIVMSG Angel :yes I'm receiving it ! ; Command to send a message to Angel. PRIVMSG jto@tolsun.oulu.fi :Hello ! ; Command to send a message to a user on server tolsun.oulu.fi with username of "jto". PRIVMSG kalt%millennium.stealth.net@irc.stealth.net :Are you a frog? ; Message to a user on server irc.stealth.net with username of "kalt", and connected from the host millennium.stealth.net. PRIVMSG kalt%millennium.stealth.net :Do you like cheese? ; Message to a user on the local server with username of "kalt", and connected from the host millennium.stealth.net. PRIVMSG Wiz!jto@tolsun.oulu.fi :Hello ! ; Message to the user with nickname Wiz who is connected from the host tolsun.oulu.fi and has the username "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. 3.3.2 Notice Command: NOTICE Parameters: <msgtarget> <text> The NOTICE command 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 Kalt Informational [Page 24]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 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 clients automatically sending something in response to something it received. This command is available to services as well as users. This is typically used by services, and automatons (clients with either an AI or other interactive program controlling their actions). See PRIVMSG for more details on replies and examples. 3.4 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. In these queries, where a parameter appears as <target>, wildcard masks are usually valid. For each parameter, however, only one query and set of replies is to be generated. In most cases, if a nickname is given, it will mean the server to which the user is connected. These messages typically have little value for services, it is therefore RECOMMENDED to forbid services from using them. 3.4.1 Motd message Command: MOTD Parameters: [ <target> ] The MOTD command is used to get the "Message Of The Day" of the given server, or current server if <target> is omitted. Wildcards are allowed in the <target> parameter. Numeric Replies: RPL_MOTDSTART RPL_MOTD RPL_ENDOFMOTD ERR_NOMOTD 3.4.2 Lusers message Command: LUSERS Parameters: [ <mask> [ <target> ] ] The LUSERS command is used to get statistics about the size of the IRC network. If no parameter is given, the reply will be about the whole net. If a <mask> is specified, then the reply will only Kalt Informational [Page 25]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 concern the part of the network formed by the servers matching the mask. Finally, if the <target> parameter is specified, the request is forwarded to that server which will generate the reply. Wildcards are allowed in the <target> parameter. Numeric Replies: RPL_LUSERCLIENT RPL_LUSEROP RPL_LUSERUNKOWN RPL_LUSERCHANNELS RPL_LUSERME ERR_NOSUCHSERVER 3.4.3 Version message Command: VERSION Parameters: [ <target> ] The VERSION command is used to query the version of the server program. An optional parameter <target> is used to query the version of the server program which a client is not directly connected to. Wildcards are allowed in the <target> parameter. Numeric Replies: ERR_NOSUCHSERVER RPL_VERSION Examples: VERSION tolsun.oulu.fi ; Command to check the version of server "tolsun.oulu.fi". 3.4.4 Stats message Command: STATS Parameters: [ <query> [ <target> ] ] The stats command is used to query statistics of certain server. If <query> parameter is omitted, only the end of stats reply is sent back. A query may be given for any single letter which is only checked by the destination server and is otherwise passed on by intermediate servers, ignored and unaltered. Wildcards are allowed in the <target> parameter. Kalt Informational [Page 26]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 Except for the ones below, the list of valid queries is implementation dependent. The standard queries below SHOULD be supported by the server: l - returns a list of the server's connections, showing how long each connection has been established and the traffic over that connection in Kbytes and messages for each direction; m - returns the usage count for each of commands supported by the server; commands for which the usage count is zero MAY be omitted; o - returns a list of configured privileged users, operators; u - returns a string showing how long the server has been up. It is also RECOMMENDED that client and server access configuration be published this way. Numeric Replies: ERR_NOSUCHSERVER RPL_STATSLINKINFO RPL_STATSUPTIME RPL_STATSCOMMANDS RPL_STATSOLINE RPL_ENDOFSTATS Examples: STATS m ; Command to check the command usage for the server you are connected to 3.4.5 Links message Command: LINKS Parameters: [ [ <remote server> ] <server mask> ] With LINKS, a user can list all servernames, 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 Kalt Informational [Page 27]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 Examples: LINKS *.au ; Command to list all servers which have a name that matches *.au; LINKS *.edu *.bu.edu ; Command to list servers matching *.bu.edu as seen by the first server matching *.edu. 3.4.6 Time message Command: TIME Parameters: [ <target> ] The time command is used to query local time from the specified server. If the <target> parameter is not given, the server receiving the command must reply to the query. Wildcards are allowed in the <target> parameter. Numeric Replies: ERR_NOSUCHSERVER RPL_TIME Examples: TIME tolsun.oulu.fi ; check the time on the server "tolson.oulu.fi" 3.4.7 Connect message Command: CONNECT Parameters: <target server> <port> [ <remote server> ] The CONNECT command can be used to request a server to try to establish a new connection to another server immediately. CONNECT is a privileged command and SHOULD be available only to IRC Operators. If a <remote server> is given and its mask doesn't match name of the parsing server, the CONNECT attempt is sent to the first match of remote server. Otherwise the CONNECT attempt is made by the server processing the request. The server receiving a remote CONNECT command SHOULD generate a WALLOPS message describing the source and target of the request. Numeric Replies: ERR_NOSUCHSERVER ERR_NOPRIVILEGES ERR_NEEDMOREPARAMS Kalt Informational [Page 28]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 Examples: CONNECT tolsun.oulu.fi 6667 ; Command to attempt to connect local server to tolsun.oulu.fi on port 6667 3.4.8 Trace message Command: TRACE Parameters: [ <target> ] TRACE command is used to find the route to specific server and information about its peers. Each server that processes this command MUST report to the sender about it. The replies from pass-through links form a chain, which shows route to destination. After sending this reply back, the query MUST be sent to the next server until given <target> server is reached. 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. After sending this reply back, it MUST then send the TRACE message to the next server until given server is reached. If the <target> parameter is omitted, it is RECOMMENDED that TRACE command sends a message to the sender telling which servers the local server has direct connection to. If the destination given by <target> is an actual server, the destination server is REQUIRED to report all servers, services and operators which are connected to it; if the command was issued by an operator, the server MAY also report all users which are connected to it. If the destination given by <target> is a nickname, then only a reply for that nickname is given. If the <target> parameter is omitted, it is RECOMMENDED that the TRACE command is parsed as targeted to the processing server. Wildcards are allowed in the <target> parameter. 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 it is going next. RPL_TRACELINK Kalt Informational [Page 29]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 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 RPL_TRACELOG RPL_TRACEEND Examples: TRACE *.oulu.fi ; TRACE to a server matching *.oulu.fi 3.4.9 Admin command Command: ADMIN Parameters: [ <target> ] The admin command is used to find information about the administrator of the given server, or current server if <target> parameter is omitted. Each server MUST have the ability to forward ADMIN messages to other servers. Wildcards are allowed in the <target> parameter. 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 ADMIN syrk ; ADMIN request for the server to which the user syrk is connected Kalt Informational [Page 30]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 3.4.10 Info command Command: INFO Parameters: [ <target> ] The INFO command is REQUIRED to return information describing 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. Wildcards are allowed in the <target> parameter. Numeric Replies: ERR_NOSUCHSERVER RPL_INFO RPL_ENDOFINFO Examples: INFO csd.bu.edu ; request an INFO reply from csd.bu.edu INFO Angel ; request info from the server that Angel is connected to. 3.5 Service Query and Commands The service query group of commands has been designed to return information about any service which is connected to the network. 3.5.1 Servlist message Command: SERVLIST Parameters: [ <mask> [ <type> ] ] The SERVLIST command is used to list services currently connected to the network and visible to the user issuing the command. The optional parameters may be used to restrict the result of the query (to matching services names, and services type). Numeric Replies: RPL_SERVLIST RPL_SERVLISTEND Kalt Informational [Page 31]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 3.5.2 Squery Command: SQUERY Parameters: <servicename> <text> The SQUERY command is used similarly to PRIVMSG. The only difference is that the recipient MUST be a service. This is the only way for a text message to be delivered to a service. See PRIVMSG for more details on replies and example. Examples: SQUERY irchelp :HELP privmsg ; Message to the service with nickname irchelp. SQUERY dict@irc.fr :fr2en blaireau ; Message to the service with name dict@irc.fr. 3.6 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. Although services SHOULD NOT be using this class of message, they are allowed to. 3.6.1 Who query Command: WHO Parameters: [ <mask> [ "o" ] ] The WHO command is used by a client to generate a query which returns a list of information which 'matches' the <mask> parameter given by the client. In the absence of the <mask> 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 <mask> of "0" or any wildcard which will end up matching every visible user. The <mask> passed to WHO is matched against users' host, server, real name and nickname if the channel <mask> cannot be found. Kalt Informational [Page 32]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 If the "o" parameter is passed only operators are returned according to the <mask> supplied. Numeric Replies: ERR_NOSUCHSERVER RPL_WHOREPLY RPL_ENDOFWHO Examples: WHO *.fi ; Command to list all users who match against "*.fi". WHO jto* o ; Command to list all users with a match against "jto*" if they are an operator. 3.6.2 Whois query Command: WHOIS Parameters: [ <target> ] <mask> *( "," <mask> ) This command is used to query information about particular user. The server will answer this command with several numeric messages indicating different statuses of each user which matches the mask (if you are entitled to see them). If no wildcard is present in the <mask>, any information about that nick which you are allowed to see is presented. If the <target> parameter is specified, it 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 (i.e., the server the user is directly connected to) knows that information, while everything else is globally known. Wildcards are allowed in the <target> parameter. Numeric Replies: ERR_NOSUCHSERVER ERR_NONICKNAMEGIVEN RPL_WHOISUSER RPL_WHOISCHANNELS RPL_WHOISCHANNELS RPL_WHOISSERVER RPL_AWAY RPL_WHOISOPERATOR RPL_WHOISIDLE ERR_NOSUCHNICK RPL_ENDOFWHOIS Kalt Informational [Page 33]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 Examples: WHOIS wiz ; return available user information about nick WiZ WHOIS eff.org trillian ; ask server eff.org for user information about trillian 3.6.3 Whowas Command: WHOWAS Parameters: <nickname> *( "," <nickname> ) [ <count> [ <target> ] ] 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. Wildcards are allowed in the <target> parameter. 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". 3.7 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. Kalt Informational [Page 34]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 3.7.1 Kill message Command: KILL Parameters: <nickname> <comment> The KILL command is used to cause a client-server connection to be closed by the server which has the actual connection. Servers generate KILL messages on nickname collisions. It MAY also be available available to users who have the operator status. 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 'flooding' from abusive users or accidents. Abusive users usually don't care as they will reconnect promptly and resume their abusive behaviour. To prevent this command from 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. When a client is removed as the result of a KILL message, the server SHOULD add the nickname to the list of unavailable nicknames in an attempt to avoid clients to reuse this name immediately which is usually the pattern of abusive behaviour often leading to useless "KILL loops". See the "IRC Server Protocol" document [IRC-SERVER] for more information on this procedure. 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 Kalt Informational [Page 35]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 NOTE: It is RECOMMENDED that only Operators be allowed to kill other users with KILL command. This command has been the subject of many controversies over the years, and along with the above recommendation, it is also widely recognized that not even operators should be allowed to kill users on remote servers. 3.7.2 Ping message Command: PING Parameters: <server1> [ <server2> ] The PING command is used to test the presence of an active client or server at the other end of the connection. Servers send a PING message at regular intervals if no other activity detected coming from a connection. If a connection fails to respond to a PING message within a set amount of time, that connection is closed. A PING message MAY be sent even if the connection is active. When a PING message is received, the appropriate PONG message MUST be sent as reply to <server1> (server which sent the PING message out) as soon as possible. If the <server2> parameter is specified, it represents the target of the ping, and the message gets forwarded there. Numeric Replies: ERR_NOORIGIN ERR_NOSUCHSERVER Examples: PING tolsun.oulu.fi ; Command to send a PING message to server PING WiZ tolsun.oulu.fi ; Command from WiZ to send a PING message to server "tolsun.oulu.fi" PING :irc.funet.fi ; Ping message sent by server "irc.funet.fi" Kalt Informational [Page 36]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 3.7.3 Pong message Command: PONG Parameters: <server> [ <server2> ] PONG message is a reply to ping message. If parameter <server2> is given, this message MUST be forwarded to given target. The <server> parameter is the name of the entity who has responded to PING message and generated this message. Numeric Replies: ERR_NOORIGIN ERR_NOSUCHSERVER Example: PONG csd.bu.edu tolsun.oulu.fi ; PONG message from csd.bu.edu to tolsun.oulu.fi 3.7.4 Error Command: ERROR Parameters: <error message> The ERROR command is for use by servers when reporting a serious or fatal error to its peers. It may also be sent from one server to another but MUST NOT be accepted from any normal unknown clients. Only an ERROR message SHOULD be used for reporting errors which occur with a server-to-server link. An ERROR message is sent to the server at the other end (which reports it to appropriate local users and logs) and to appropriate local users and logs. It is not to be passed onto any other servers by a server if it is received from a server. The ERROR message is also used before terminating a client connection. 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. Kalt Informational [Page 37]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 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. 4. Optional features This section describes OPTIONAL messages. They are not required in a working server implementation of the protocol described herein. In the absence of the feature, 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. From this section, only the USERHOST and ISON messages are available to services. 4.1 Away Command: AWAY Parameters: [ <text> ] With the AWAY command, clients can set an automatic reply string for any PRIVMSG commands directed at them (not to a channel they are on). The server sends an automatic reply to the client sending the PRIVMSG command. The only replying server is the one to which the sending client is connected to. The AWAY command is used either with one parameter, to set an AWAY message, or with no parameters, to remove the AWAY message. Because of its high cost (memory and bandwidth wise), the AWAY message SHOULD only be used for client-server communication. A server MAY choose to silently ignore AWAY messages received from other servers. To update the away status of a client across servers, the user mode 'a' SHOULD be used instead. (See Section 3.1.5) Numeric Replies: RPL_UNAWAY RPL_NOWAWAY Kalt Informational [Page 38]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 Example: AWAY :Gone to lunch. Back in 5 ; Command to set away message to "Gone to lunch. Back in 5". 4.2 Rehash message Command: REHASH Parameters: None The rehash command is an administrative command which can be used by an operator to force the server to re-read and process its configuration file. Numeric Replies: RPL_REHASHING ERR_NOPRIVILEGES Example: REHASH ; message from user with operator status to server asking it to reread its configuration file. 4.3 Die message Command: DIE Parameters: None An operator can use the DIE command to shutdown the server. 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. The DIE command MUST always be fully processed by the server to which the sending client is connected and MUST NOT be passed onto other connected servers. Numeric Replies: ERR_NOPRIVILEGES Example: DIE ; no parameters required. Kalt Informational [Page 39]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 4.4 Restart message Command: RESTART Parameters: None An operator can use the restart command to force the server to 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. The RESTART command MUST always be fully processed by the server to which the sending client is connected and MUST NOT be passed onto other connected servers. Numeric Replies: ERR_NOPRIVILEGES Example: RESTART ; no parameters required. 4.5 Summon message Command: SUMMON Parameters: <user> [ <target> [ <channel> ] ] The SUMMON command can be used to give users who are on a host running an IRC server a message asking them to please join IRC. This message is only sent if the target server (a) has SUMMON enabled, (b) the user is logged in and (c) the server process can write to the user's tty (or similar). If no <server> parameter is given it tries to summon <user> from the server the client is connected to is assumed as the target. If summon is not enabled in a server, it MUST return the ERR_SUMMONDISABLED numeric. Numeric Replies: ERR_NORECIPIENT ERR_FILEERROR ERR_NOLOGIN ERR_NOSUCHSERVER ERR_SUMMONDISABLED RPL_SUMMONING Kalt Informational [Page 40]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 Examples: SUMMON jto ; summon user jto on the server's host SUMMON jto tolsun.oulu.fi ; summon user jto on the host which a server named "tolsun.oulu.fi" is running. 4.6 Users Command: USERS Parameters: [ <target> ] The USERS command returns a list of users logged into the server in a format similar to the UNIX commands who(1), rusers(1) and finger(1). If disabled, the correct numeric MUST be returned to indicate this. Because of the security implications of such a command, it SHOULD be disabled by default in server implementations. Enabling it SHOULD require recompiling the server or some equivalent change rather than simply toggling an option and restarting the server. The procedure to enable this command SHOULD also include suitable large comments. Numeric Replies: ERR_NOSUCHSERVER ERR_FILEERROR RPL_USERSSTART RPL_USERS RPL_NOUSERS RPL_ENDOFUSERS ERR_USERSDISABLED Disabled Reply: ERR_USERSDISABLED Example: USERS eff.org ; request a list of users logged in on server eff.org 4.7 Operwall message Command: WALLOPS Parameters: <Text to be sent> The WALLOPS command is used to send a message to all currently connected users who have set the 'w' user mode for themselves. (See Section 3.1.5 "User modes"). Kalt Informational [Page 41]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 After implementing WALLOPS as a user command it was found that it was often and commonly abused as a means of sending a message to a lot of people. Due to this, it is RECOMMENDED that the implementation of WALLOPS allows and recognizes only servers as the originators of WALLOPS. Numeric Replies: ERR_NEEDMOREPARAMS Example: :csd.bu.edu WALLOPS :Connect '*.uiuc.edu 6667' from Joshua ; WALLOPS message from csd.bu.edu announcing a CONNECT message it received from Joshua and acted upon. 4.8 Userhost message Command: USERHOST Parameters: <nickname> *( SPACE <nickname> ) The USERHOST command takes a list of up to 5 nicknames, each separated by a space character and returns a list of information about each nickname that it found. The returned list has each reply separated by a space. Numeric Replies: RPL_USERHOST ERR_NEEDMOREPARAMS Example: USERHOST Wiz Michael syrk ; USERHOST request for information on nicks "Wiz", "Michael", and "syrk" :ircd.stealth.net 302 yournick :syrk=+syrk@millennium.stealth.net ; Reply for user syrk 4.9 Ison message Command: ISON Parameters: <nickname> *( SPACE <nickname> ) The ISON command was implemented to provide a quick and efficient means to get a response about whether a given nickname was currently on IRC. ISON only takes one (1) type of parameter: a space-separated list of nicks. For each nickname in the list that is present, the Kalt Informational [Page 42]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 server adds that to its reply string. Thus the reply string may return empty (none of the given nicks are present), an exact copy of the parameter string (all of them present) or any other subset of the set of nicks given in the parameter. The only limit on the number of nicks that may be checked is that the combined length MUST NOT be too large as to cause the server to chop it off so it fits in 512 characters. ISON is only processed by the server local to the client sending the command and thus not passed onto other servers for further processing. Numeric Replies: RPL_ISON ERR_NEEDMOREPARAMS Example: ISON phone trillian WiZ jarlek Avalon Angel Monstah syrk ; Sample ISON request for 7 nicks. 5. Replies The following is a list of numeric replies which are generated in response to the commands given above. Each numeric is given with its number, name and reply string. 5.1 Command responses Numerics in the range from 001 to 099 are used for client-server connections only and should never travel between servers. Replies generated in the response to commands are found in the range from 200 to 399. 001 RPL_WELCOME "Welcome to the Internet Relay Network <nick>!<user>@<host>" 002 RPL_YOURHOST "Your host is <servername>, running version <ver>" 003 RPL_CREATED "This server was created <date>" 004 RPL_MYINFO "<servername> <version> <available user modes> <available channel modes>" - The server sends Replies 001 to 004 to a user upon successful registration. Kalt Informational [Page 43]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 005 RPL_BOUNCE "Try server <server name>, port <port number>" - Sent by the server to a user to suggest an alternative server. This is often used when the connection is refused because the server is already full. 302 RPL_USERHOST ":*1<reply> *( " " <reply> )" - Reply format used by USERHOST to list replies to the query list. The reply string is composed as follows: reply = nickname [ "*" ] "=" ( "+" / "-" ) hostname The '*' indicates whether the client has registered as an Operator. The '-' or '+' characters represent whether the client has set an AWAY message or not respectively. 303 RPL_ISON ":*1<nick> *( " " <nick> )" - Reply format used by ISON to list replies to the query list. 301 RPL_AWAY "<nick> :<away message>" 305 RPL_UNAWAY ":You are no longer marked as being away" 306 RPL_NOWAWAY ":You have been marked as being away" - These replies are used with the AWAY command (if allowed). RPL_AWAY is sent to any client sending a PRIVMSG to a client which is away. RPL_AWAY is only sent by the server to which the client is connected. Replies RPL_UNAWAY and RPL_NOWAWAY are sent when the client removes and sets an AWAY message. 311 RPL_WHOISUSER "<nick> <user> <host> * :<real name>" 312 RPL_WHOISSERVER "<nick> <server> :<server info>" 313 RPL_WHOISOPERATOR "<nick> :is an IRC operator" Kalt Informational [Page 44]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 317 RPL_WHOISIDLE "<nick> <integer> :seconds idle" 318 RPL_ENDOFWHOIS "<nick> :End of WHOIS list" 319 RPL_WHOISCHANNELS "<nick> :*( ( "@" / "+" ) <channel> " " )" - Replies 311 - 313, 317 - 319 are all replies generated in response to a WHOIS message. Given that there are enough parameters present, the answering server MUST either formulate a reply out of the above numerics (if the query nick is found) or return an error reply. The '*' in RPL_WHOISUSER is there as the literal character and not as a wild card. For each reply set, only RPL_WHOISCHANNELS may appear more than once (for long lists of channel names). The '@' and '+' characters next to the channel name indicate whether a client is a channel operator or has been granted permission to speak on a moderated channel. The RPL_ENDOFWHOIS reply is used to mark the end of processing a WHOIS message. 314 RPL_WHOWASUSER "<nick> <user> <host> * :<real name>" 369 RPL_ENDOFWHOWAS "<nick> :End of WHOWAS" - When replying to a WHOWAS message, a server MUST use the replies RPL_WHOWASUSER, RPL_WHOISSERVER or ERR_WASNOSUCHNICK for each nickname in the presented list. At the end of all reply batches, there MUST be RPL_ENDOFWHOWAS (even if there was only one reply and it was an error). 321 RPL_LISTSTART Obsolete. Not used. 322 RPL_LIST "<channel> <# visible> :<topic>" 323 RPL_LISTEND ":End of LIST" - Replies RPL_LIST, RPL_LISTEND mark the actual replies with data and end of the server's response to a LIST command. If there are no channels available to return, only the end reply MUST be sent. Kalt Informational [Page 45]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 325 RPL_UNIQOPIS "<channel> <nickname>" 324 RPL_CHANNELMODEIS "<channel> <mode> <mode params>" 331 RPL_NOTOPIC "<channel> :No topic is set" 332 RPL_TOPIC "<channel> :<topic>" - When sending a TOPIC message to determine the channel topic, one of two replies is sent. If the topic is set, RPL_TOPIC is sent back else RPL_NOTOPIC. 341 RPL_INVITING "<channel> <nick>" - Returned by the server to indicate that the attempted INVITE message was successful and is being passed onto the end client. 342 RPL_SUMMONING "<user> :Summoning user to IRC" - Returned by a server answering a SUMMON message to indicate that it is summoning that user. 346 RPL_INVITELIST "<channel> <invitemask>" 347 RPL_ENDOFINVITELIST "<channel> :End of channel invite list" - When listing the 'invitations masks' for a given channel, a server is required to send the list back using the RPL_INVITELIST and RPL_ENDOFINVITELIST messages. A separate RPL_INVITELIST is sent for each active mask. After the masks have been listed (or if none present) a RPL_ENDOFINVITELIST MUST be sent. 348 RPL_EXCEPTLIST "<channel> <exceptionmask>" 349 RPL_ENDOFEXCEPTLIST "<channel> :End of channel exception list" Kalt Informational [Page 46]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 - When listing the 'exception masks' for a given channel, a server is required to send the list back using the RPL_EXCEPTLIST and RPL_ENDOFEXCEPTLIST messages. A separate RPL_EXCEPTLIST is sent for each active mask. After the masks have been listed (or if none present) a RPL_ENDOFEXCEPTLIST MUST be sent. 351 RPL_VERSION "<version>.<debuglevel> <server> :<comments>" - Reply by the server showing its version details. The <version> is the version of the software being used (including any patchlevel revisions) and the <debuglevel> is used to indicate if the server is running in "debug mode". The "comments" field may contain any comments about the version or further version details. 352 RPL_WHOREPLY "<channel> <user> <host> <server> <nick> ( "H" / "G" > ["*"] [ ( "@" / "+" ) ] :<hopcount> <real name>" 315 RPL_ENDOFWHO "<name> :End of WHO list" - The RPL_WHOREPLY and RPL_ENDOFWHO pair are used to answer a WHO message. The RPL_WHOREPLY is only sent if there is an appropriate match to the WHO query. If there is a list of parameters supplied with a WHO message, a RPL_ENDOFWHO MUST be sent after processing each list item with <name> being the item. 353 RPL_NAMREPLY "( "=" / "*" / "@" ) <channel> :[ "@" / "+" ] <nick> *( " " [ "@" / "+" ] <nick> ) - "@" is used for secret channels, "*" for private channels, and "=" for others (public channels). 366 RPL_ENDOFNAMES "<channel> :End of NAMES list" - To reply to a NAMES message, a reply pair consisting of RPL_NAMREPLY and RPL_ENDOFNAMES is sent by the server back to the client. If there is no channel found as in the query, then only RPL_ENDOFNAMES is Kalt Informational [Page 47]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 returned. The exception to this is when a NAMES message is sent with no parameters and all visible channels and contents are sent back in a series of RPL_NAMEREPLY messages with a RPL_ENDOFNAMES to mark the end. 364 RPL_LINKS "<mask> <server> :<hopcount> <server info>" 365 RPL_ENDOFLINKS "<mask> :End of LINKS list" - In replying to the LINKS message, a server MUST send replies back using the RPL_LINKS numeric and mark the end of the list using an RPL_ENDOFLINKS reply. 367 RPL_BANLIST "<channel> <banmask>" 368 RPL_ENDOFBANLIST "<channel> :End of channel ban list" - When listing the active 'bans' for a given channel, a server is required to send the list back using the RPL_BANLIST and RPL_ENDOFBANLIST messages. A separate RPL_BANLIST is sent for each active banmask. After the banmasks have been listed (or if none present) a RPL_ENDOFBANLIST MUST be sent. 371 RPL_INFO ":<string>" 374 RPL_ENDOFINFO ":End of INFO list" - A server responding to an INFO message is required to send all its 'info' in a series of RPL_INFO messages with a RPL_ENDOFINFO reply to indicate the end of the replies. 375 RPL_MOTDSTART ":- <server> Message of the day - " 372 RPL_MOTD ":- <text>" 376 RPL_ENDOFMOTD ":End of MOTD command" - When responding to the MOTD message and the MOTD file is found, the file is displayed line by line, with each line no longer than 80 characters, using Kalt Informational [Page 48]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 RPL_MOTD format replies. These MUST be surrounded by a RPL_MOTDSTART (before the RPL_MOTDs) and an RPL_ENDOFMOTD (after). 381 RPL_YOUREOPER ":You are now an IRC operator" - RPL_YOUREOPER is sent back to a client which has just successfully issued an OPER message and gained operator status. 382 RPL_REHASHING "<config file> :Rehashing" - If the REHASH option is used and an operator sends a REHASH message, an RPL_REHASHING is sent back to the operator. 383 RPL_YOURESERVICE "You are service <servicename>" - Sent by the server to a service upon successful registration. 391 RPL_TIME "<server> :<string showing server's local time>" - When replying to the TIME message, a server MUST send the reply using the RPL_TIME format above. The string showing the time need only contain the correct day and time there. There is no further requirement for the time string. 392 RPL_USERSSTART ":UserID Terminal Host" 393 RPL_USERS ":<username> <ttyline> <hostname>" 394 RPL_ENDOFUSERS ":End of users" 395 RPL_NOUSERS ":Nobody logged in" - If the USERS message is handled by a server, the replies RPL_USERSTART, RPL_USERS, RPL_ENDOFUSERS and RPL_NOUSERS are used. RPL_USERSSTART MUST be sent first, following by either a sequence of RPL_USERS or a single RPL_NOUSER. Following this is RPL_ENDOFUSERS. Kalt Informational [Page 49]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 200 RPL_TRACELINK "Link <version & debug level> <destination> <next server> V<protocol version> <link uptime in seconds> <backstream sendq> <upstream sendq>" 201 RPL_TRACECONNECTING "Try. <class> <server>" 202 RPL_TRACEHANDSHAKE "H.S. <class> <server>" 203 RPL_TRACEUNKNOWN "???? <class> [<client IP address in dot form>]" 204 RPL_TRACEOPERATOR "Oper <class> <nick>" 205 RPL_TRACEUSER "User <class> <nick>" 206 RPL_TRACESERVER "Serv <class> <int>S <int>C <server> <nick!user|*!*>@<host|server> V<protocol version>" 207 RPL_TRACESERVICE "Service <class> <name> <type> <active type>" 208 RPL_TRACENEWTYPE "<newtype> 0 <client name>" 209 RPL_TRACECLASS "Class <class> <count>" 210 RPL_TRACERECONNECT Unused. 261 RPL_TRACELOG "File <logfile> <debug level>" 262 RPL_TRACEEND "<server name> <version & debug level> :End of TRACE" - The RPL_TRACE* are all returned by the server in response to the TRACE message. How many are returned is dependent on the TRACE message and whether it was sent by an operator or not. There is no predefined order for which occurs first. Replies RPL_TRACEUNKNOWN, RPL_TRACECONNECTING and RPL_TRACEHANDSHAKE are all used for connections which have not been fully established and are either unknown, still attempting to connect or in the process of completing the 'server handshake'. RPL_TRACELINK is sent by any server which handles a TRACE message and has to pass it on to another server. The list of RPL_TRACELINKs sent in response to a TRACE command traversing the IRC network should reflect the actual connectivity of the servers themselves along that path. Kalt Informational [Page 50]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 RPL_TRACENEWTYPE is to be used for any connection which does not fit in the other categories but is being displayed anyway. RPL_TRACEEND is sent to indicate the end of the list. 211 RPL_STATSLINKINFO "<linkname> <sendq> <sent messages> <sent Kbytes> <received messages> <received Kbytes> <time open>" - reports statistics on a connection. <linkname> identifies the particular connection, <sendq> is the amount of data that is queued and waiting to be sent <sent messages> the number of messages sent, and <sent Kbytes> the amount of data sent, in Kbytes. <received messages> and <received Kbytes> are the equivalent of <sent messages> and <sent Kbytes> for received data, respectively. <time open> indicates how long ago the connection was opened, in seconds. 212 RPL_STATSCOMMANDS "<command> <count> <byte count> <remote count>" - reports statistics on commands usage. 219 RPL_ENDOFSTATS "<stats letter> :End of STATS report" 242 RPL_STATSUPTIME ":Server Up %d days %d:%02d:%02d" - reports the server uptime. 243 RPL_STATSOLINE "O <hostmask> * <name>" - reports the allowed hosts from where user may become IRC operators. 221 RPL_UMODEIS "<user mode string>" - To answer a query about a client's own mode, RPL_UMODEIS is sent back. 234 RPL_SERVLIST "<name> <server> <mask> <type> <hopcount> <info>" Kalt Informational [Page 51]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 235 RPL_SERVLISTEND "<mask> <type> :End of service listing" - When listing services in reply to a SERVLIST message, a server is required to send the list back using the RPL_SERVLIST and RPL_SERVLISTEND messages. A separate RPL_SERVLIST is sent for each service. After the services have been listed (or if none present) a RPL_SERVLISTEND MUST be sent. 251 RPL_LUSERCLIENT ":There are <integer> users and <integer> services on <integer> servers" 252 RPL_LUSEROP "<integer> :operator(s) online" 253 RPL_LUSERUNKNOWN "<integer> :unknown connection(s)" 254 RPL_LUSERCHANNELS "<integer> :channels formed" 255 RPL_LUSERME ":I have <integer> clients and <integer> servers" - In processing an LUSERS message, the server sends a set of replies from RPL_LUSERCLIENT, RPL_LUSEROP, RPL_USERUNKNOWN, RPL_LUSERCHANNELS and RPL_LUSERME. When replying, a server MUST send back RPL_LUSERCLIENT and RPL_LUSERME. The other replies are only sent back if a non-zero count is found for them. 256 RPL_ADMINME "<server> :Administrative info" 257 RPL_ADMINLOC1 ":<admin info>" 258 RPL_ADMINLOC2 ":<admin info>" 259 RPL_ADMINEMAIL ":<admin info>" - When replying to an ADMIN message, a server is expected to use replies RPL_ADMINME through to RPL_ADMINEMAIL and provide a text message with each. For RPL_ADMINLOC1 a description of what city, state and country the server is in is expected, followed by details of the institution (RPL_ADMINLOC2) Kalt Informational [Page 52]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 and finally the administrative contact for the server (an email address here is REQUIRED) in RPL_ADMINEMAIL. 263 RPL_TRYAGAIN "<command> :Please wait a while and try again." - When a server drops a command without processing it, it MUST use the reply RPL_TRYAGAIN to inform the originating client. 5.2 Error Replies Error replies are found in the range from 400 to 599. 401 ERR_NOSUCHNICK "<nickname> :No such nick/channel" - Used to indicate the nickname parameter supplied to a command is currently unused. 402 ERR_NOSUCHSERVER "<server name> :No such server" - Used to indicate the server name given currently does not exist. 403 ERR_NOSUCHCHANNEL "<channel name> :No such channel" - Used to indicate the given channel name is invalid. 404 ERR_CANNOTSENDTOCHAN "<channel name> :Cannot send to channel" - Sent to a user who is either (a) not on a channel which is mode +n or (b) not a chanop (or mode +v) on a channel which has mode +m set or where the user is banned and is trying to send a PRIVMSG message to that channel. 405 ERR_TOOMANYCHANNELS "<channel name> :You have joined too many channels" - Sent to a user when they have joined the maximum number of allowed channels and they try to join another channel. Kalt Informational [Page 53]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 406 ERR_WASNOSUCHNICK "<nickname> :There was no such nickname" - Returned by WHOWAS to indicate there is no history information for that nickname. 407 ERR_TOOMANYTARGETS "<target> :<error code> recipients. <abort message>" - Returned to a client which is attempting to send a PRIVMSG/NOTICE using the user@host destination format and for a user@host which has several occurrences. - Returned to a client which trying to send a PRIVMSG/NOTICE to too many recipients. - Returned to a client which is attempting to JOIN a safe channel using the shortname when there are more than one such channel. 408 ERR_NOSUCHSERVICE "<service name> :No such service" - Returned to a client which is attempting to send a SQUERY to a service which does not exist. 409 ERR_NOORIGIN ":No origin specified" - PING or PONG message missing the originator parameter. 411 ERR_NORECIPIENT ":No recipient given (<command>)" 412 ERR_NOTEXTTOSEND ":No text to send" 413 ERR_NOTOPLEVEL "<mask> :No toplevel domain specified" 414 ERR_WILDTOPLEVEL "<mask> :Wildcard in toplevel domain" 415 ERR_BADMASK "<mask> :Bad Server/host mask" - 412 - 415 are returned by PRIVMSG to indicate that the message wasn't delivered for some reason. ERR_NOTOPLEVEL and ERR_WILDTOPLEVEL are errors that are returned when an invalid use of "PRIVMSG $<server>" or "PRIVMSG #<host>" is attempted. Kalt Informational [Page 54]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 421 ERR_UNKNOWNCOMMAND "<command> :Unknown command" - Returned to a registered client to indicate that the command sent is unknown by the server. 422 ERR_NOMOTD ":MOTD File is missing" - Server's MOTD file could not be opened by the server. 423 ERR_NOADMININFO "<server> :No administrative info available" - Returned by a server in response to an ADMIN message when there is an error in finding the appropriate information. 424 ERR_FILEERROR ":File error doing <file op> on <file>" - Generic error message used to report a failed file operation during the processing of a message. 431 ERR_NONICKNAMEGIVEN ":No nickname given" - Returned when a nickname parameter expected for a command and isn't found. 432 ERR_ERRONEUSNICKNAME "<nick> :Erroneous nickname" - Returned after receiving a NICK message which contains characters which do not fall in the defined set. See section 2.3.1 for details on valid nicknames. 433 ERR_NICKNAMEINUSE "<nick> :Nickname is already in use" - Returned when a NICK message is processed that results in an attempt to change to a currently existing nickname. Kalt Informational [Page 55]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 436 ERR_NICKCOLLISION "<nick> :Nickname collision KILL from <user>@<host>" - Returned by a server to a client when it detects a nickname collision (registered of a NICK that already exists by another server). 437 ERR_UNAVAILRESOURCE "<nick/channel> :Nick/channel is temporarily unavailable" - Returned by a server to a user trying to join a channel currently blocked by the channel delay mechanism. - Returned by a server to a user trying to change nickname when the desired nickname is blocked by the nick delay mechanism. 441 ERR_USERNOTINCHANNEL "<nick> <channel> :They aren't on that channel" - Returned by the server to indicate that the target user of the command is not on the given channel. 442 ERR_NOTONCHANNEL "<channel> :You're not on that channel" - Returned by the server whenever a client tries to perform a channel affecting command for which the client isn't a member. 443 ERR_USERONCHANNEL "<user> <channel> :is already on channel" - Returned when a client tries to invite a user to a channel they are already on. 444 ERR_NOLOGIN "<user> :User not logged in" - Returned by the summon after a SUMMON command for a user was unable to be performed since they were not logged in. Kalt Informational [Page 56]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 445 ERR_SUMMONDISABLED ":SUMMON has been disabled" - Returned as a response to the SUMMON command. MUST be returned by any server which doesn't implement it. 446 ERR_USERSDISABLED ":USERS has been disabled" - Returned as a response to the USERS command. MUST be returned by any server which does not implement it. 451 ERR_NOTREGISTERED ":You have not registered" - Returned by the server to indicate that the client MUST be registered before the server will allow it to be parsed in detail. 461 ERR_NEEDMOREPARAMS "<command> :Not enough parameters" - Returned by the server by numerous commands to indicate to the client that it didn't supply enough parameters. 462 ERR_ALREADYREGISTRED ":Unauthorized command (already registered)" - Returned by the server to any link which tries to change part of the registered details (such as password or user details from second USER message). 463 ERR_NOPERMFORHOST ":Your host isn't among the privileged" - Returned to a client which attempts to register with a server which does not been setup to allow connections from the host the attempted connection is tried. 464 ERR_PASSWDMISMATCH ":Password incorrect" - Returned to indicate a failed attempt at registering a connection for which a password was required and was either not given or incorrect. Kalt Informational [Page 57]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 465 ERR_YOUREBANNEDCREEP ":You are banned from this server" - Returned after an attempt to connect and register yourself with a server which has been setup to explicitly deny connections to you. 466 ERR_YOUWILLBEBANNED - Sent by a server to a user to inform that access to the server will soon be denied. 467 ERR_KEYSET "<channel> :Channel key already set" 471 ERR_CHANNELISFULL "<channel> :Cannot join channel (+l)" 472 ERR_UNKNOWNMODE "<char> :is unknown mode char to me for <channel>" 473 ERR_INVITEONLYCHAN "<channel> :Cannot join channel (+i)" 474 ERR_BANNEDFROMCHAN "<channel> :Cannot join channel (+b)" 475 ERR_BADCHANNELKEY "<channel> :Cannot join channel (+k)" 476 ERR_BADCHANMASK "<channel> :Bad Channel Mask" 477 ERR_NOCHANMODES "<channel> :Channel doesn't support modes" 478 ERR_BANLISTFULL "<channel> <char> :Channel list is full" 481 ERR_NOPRIVILEGES ":Permission Denied- You're not an IRC operator" - Any command requiring operator privileges to operate MUST return this error to indicate the attempt was unsuccessful. 482 ERR_CHANOPRIVSNEEDED "<channel> :You're not channel operator" - Any command requiring 'chanop' privileges (such as MODE messages) MUST return this error if the client making the attempt is not a chanop on the specified channel. Kalt Informational [Page 58]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 483 ERR_CANTKILLSERVER ":You can't kill a server!" - Any attempts to use the KILL command on a server are to be refused and this error returned directly to the client. 484 ERR_RESTRICTED ":Your connection is restricted!" - Sent by the server to a user upon connection to indicate the restricted nature of the connection (user mode "+r"). 485 ERR_UNIQOPPRIVSNEEDED ":You're not the original channel operator" - Any MODE requiring "channel creator" privileges MUST return this error if the client making the attempt is not a chanop on the specified channel. 491 ERR_NOOPERHOST ":No O-lines for your host" - If a client sends an OPER message and the server has not been configured to allow connections from the client's host as an operator, this error MUST be returned. 501 ERR_UMODEUNKNOWNFLAG ":Unknown MODE flag" - Returned by the server to indicate that a MODE message was sent with a nickname parameter and that the a mode flag sent was not recognized. 502 ERR_USERSDONTMATCH ":Cannot change mode for other users" - Error sent to any user trying to view or change the user mode for a user other than themselves. 5.3 Reserved numerics These numerics are not described above since they fall into one of the following categories: 1. no longer in use; Kalt Informational [Page 59]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 2. reserved for future planned use; 3. in current use but are part of a non-generic 'feature' of the current IRC server. 231 RPL_SERVICEINFO 232 RPL_ENDOFSERVICES 233 RPL_SERVICE 300 RPL_NONE 316 RPL_WHOISCHANOP 361 RPL_KILLDONE 362 RPL_CLOSING 363 RPL_CLOSEEND 373 RPL_INFOSTART 384 RPL_MYPORTIS 213 RPL_STATSCLINE 214 RPL_STATSNLINE 215 RPL_STATSILINE 216 RPL_STATSKLINE 217 RPL_STATSQLINE 218 RPL_STATSYLINE 240 RPL_STATSVLINE 241 RPL_STATSLLINE 244 RPL_STATSHLINE 244 RPL_STATSSLINE 246 RPL_STATSPING 247 RPL_STATSBLINE 250 RPL_STATSDLINE 492 ERR_NOSERVICEHOST 6. Current implementations The IRC software, version 2.10 is the only complete implementation of the IRC protocol (client and server). Because of the small amount of changes in the client protocol since the publication of RFC 1459 [IRC], implementations that follow it are likely to be compliant with this protocol or to require a small amount of changes to reach compliance. 7. Current problems There are a number of recognized problems with the IRC Client Protocol, and more generally with the IRC Server Protocol. In order to preserve backward compatibility with old clients, this protocol has almost not evolved since the publication of RFC 1459 [IRC]. 7.1 Nicknames The idea of the nickname on IRC is very convenient for users to use when talking to each other outside of a channel, but there is only a finite nickname space and being what they are, it's not uncommon for several people to want to use the same nick. If a nickname is chosen by two people using this protocol, either one will not succeed or both will removed by use of a server KILL (See Section 3.7.1). Kalt Informational [Page 60]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 7.2 Limitation of wildcards There is no way to escape the escape character "\" (%x5C). While this isn't usually a problem, it makes it impossible to form a mask with a backslash character ("\") preceding a wildcard. 7.3 Security considerations Security issues related to this protocol are discussed in the "IRC Server Protocol" [IRC-SERVER] as they are mostly an issue for the server side of the connection. 8. Current support and availability Mailing lists for IRC related discussion: General discussion: ircd-users@irc.org Protocol development: ircd-dev@irc.org Software implementations: ftp://ftp.irc.org/irc/server ftp://ftp.funet.fi/pub/unix/irc ftp://ftp.irc.org/irc/clients Newsgroup: alt.irc 9. Acknowledgements Parts of this document were copied from the RFC 1459 [IRC] which first formally documented the IRC Protocol. It has also benefited from many rounds of review and comments. In particular, the following people have made significant contributions to this document: Matthew Green, Michael Neumayer, Volker Paulsen, Kurt Roeckx, Vesa Ruokonen, Magnus Tjernstrom, Stefan Zehl. Kalt Informational [Page 61]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 10. References [KEYWORDS] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [ABNF] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, November 1997. [HNAME] Braden, R., "Requirements for Internet Hosts -- Application and Support", STD 3, RFC 1123, October 1989. [IRC] Oikarinen, J. & D. Reed, "Internet Relay Chat Protocol", RFC 1459, May 1993. [IRC-ARCH] Kalt, C., "Internet Relay Chat: Architecture", RFC 2810, April 2000. [IRC-CHAN] Kalt, C., "Internet Relay Chat: Channel Management", RFC 2811, April 2000. [IRC-SERVER] Kalt, C., "Internet Relay Chat: Server Protocol", RFC 2813, April 2000. 11. Author's Address Christophe Kalt 99 Teaneck Rd, Apt #117 Ridgefield Park, NJ 07660 USA EMail: kalt@stealth.net Kalt Informational [Page 62]
RFC 2812 Internet Relay Chat: Client Protocol April 2000 12. Full Copyright Statement Copyright (C) The Internet Society (2000). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Acknowledgement Funding for the RFC Editor function is currently provided by the Internet Society. Kalt Informational [Page 63]

   

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