I've looked at the RFC but I am still struggling. I've written a basic client in C# but I cannot find documentation for how to connect properly.
Once I connect and transmit NICK and USER information, I need to join a channel. If I do a JOIN straight away, nothing happens - presumably because it's too soon. I have to delay it, but I don't know which command I need to wait for to know it's okay to go ahead.
I get stuff like:
:irc.fish.net NOTICE AUTH :looking up your hostname...
and
:irc.fish.net 001 FishBot :Welcome
as well as stuff with codes 002, 003, 005, 251, 252, etc. but I can't find anywhere online that shows me what these are.
So my basic 2 questions are: What do you send a JOIN in response to, and where can I find what the IRC codes above correspond to? The RFC document was useless!
The RFC documents are certainly not useless! You are correct that you need to send USER followed by NICK. The NOTICE you are getting is that the IRC server is attempting to connect back to your PC via a protocol called IDENTD. It's a relatively simple protocol but the upshot of it is that it wants to know that a program on the host that is connected to the server, is using the local/remote ports that the server has.
Chances are, your firewall is preventing this (and you're probably not running an IDENTD server). This is not a huge problem, though a fully-fledged IRC client will implement it. You can find out more here. That goes in to much more detail. It's relatively simple to implement.
Most IRC servers will give up if it cannot connect to you, and I've forgotten the exact side-effect of this (it has been a while), but the next messages you want to look out for are the MOTD_START/MOTD/MOTD_END and ERR_NOMOTD. Only after you have received the end of the Message of the day, or handled the ERR_NOMOTD (there isn't one), can you then use JOIN to join channels.
Incidentally, this is a good RegEx for matching input from an IRC Server:
^(?:[:@]([^\\s]+) )?([^\\s]+)(?: ((?:[^:\\s][^\\s]* ?)*))?(?: ?:(.*))?$
The IRC RFCs list all the possible codes and what they mean. I'm not sure why you think they are useless. Which ones have you been referencing?
EDIT
I looked up my old C++ code for IRC so I could be a bit more helpful. After connecting, it enters a stage (that I have labelled) negotiating:
Negotiating Stage:
- If a password has been specified for the server, send it
PASS mypassword.
- Send the
USER command.
- Enter the Negotiate Nickname Stage
- Wait for
ERR_NOMOTD, END_OFMOTD. Until one of these comes, you're not "officially connected".
Negotiate Nickname Stage:
It's entirely possible that during connection, the nickname you want to use is already in use. Therefore the client should:
- Issue a
NICK command
- If you receive a
ERR_NICKINUSE response, issue it again. If you have no more nicknames to use, you can either bailout or prompt the user for another one.
Some other thing to consider:
- Look our for the
PING command. The server will send this when you're idle. Handle this as high-priority and return PONG with the data the server gave you. Failure to do this will ensure you get disconnected and when you're testing an IRC client, this can be a pain in the rear-end.
Bonus Fun
This is my enum for the IRC commands, you should be able to put this in to C# easily enough:
// reply ids
enum Reply
{
RplNone = 0,
// Initial
RplWelcome = 001, // :Welcome to the Internet Relay Network <nickname>
RplYourHost = 002, // :Your host is <server>, running version <ver>
RplCreated = 003, // :This server was created <datetime>
RplMyInfo = 004, // <server> <ver> <usermode> <chanmode>
RplMap = 005, // :map
RplEndOfMap = 007, // :End of /MAP
RplMotdStart = 375, // :- server Message of the Day
RplMotd = 372, // :- <info>
RplMotdAlt = 377, // :- <info> (some)
RplMotdAlt2 = 378, // :- <info> (some)
RplMotdEnd = 376, // :End of /MOTD command.
RplUModeIs = 221, // <mode>
// IsOn/UserHost
RplUserHost = 302, // :userhosts
RplIsOn = 303, // :nicknames
// Away
RplAway = 301, // <nick> :away
RplUnAway = 305, // :You are no longer marked as being away
RplNowAway = 306, // :You have been marked as being away
// WHOIS/WHOWAS
RplWhoisHelper = 310, // <nick> :looks very helpful DALNET
RplWhoIsUser = 311, // <nick> <username> <address> * :<info>
RplWhoIsServer = 312, // <nick> <server> :<info>
RplWhoIsOperator = 313, // <nick> :is an IRC Operator
RplWhoIsIdle = 317, // <nick> <seconds> <signon> :<info>
RplEndOfWhois = 318, // <request> :End of /WHOIS list.
RplWhoIsChannels = 319, // <nick> :<channels>
RplWhoWasUser = 314, // <nick> <username> <address> * :<info>
RplEndOfWhoWas = 369, // <request> :End of WHOWAS
RplWhoReply = 352, // <channel> <username> <address> <server> <nick> <flags> :<hops> <info>
RplEndOfWho = 315, // <request> :End of /WHO list.
RplUserIPs = 307, // :userips UNDERNET
RplUserIP = 340, // <nick> :<nickname>=+<user>@<IP.address> UNDERNET
// List
RplListStart = 321, // Channel :Users Name
RplList = 322, // <channel> <users> :<topic>
RplListEnd = 323, // :End of /LIST
RplLinks = 364, // <server> <hub> :<hops> <info>
RplEndOfLinks = 365, // <mask> :End of /LINKS list.
// Post-Channel Join
RplUniqOpIs = 325,
RplChannelModeIs = 324, // <channel> <mode>
RplChannelUrl = 328, // <channel> :url DALNET
RplChannelCreated = 329, // <channel> <time>
RplNoTopic = 331, // <channel> :No topic is set.
RplTopic = 332, // <channel> :<topic>
RplTopicSetBy = 333, // <channel> <nickname> <time>
RplNamReply = 353, // = <channel> :<names>
RplEndOfNames = 366, // <channel> :End of /NAMES list.
// Invitational
RplInviting = 341, // <nick> <channel>
RplSummoning = 342,
// Channel Lists
RplInviteList = 346, // <channel> <invite> <nick> <time> IRCNET
RplEndOfInviteList = 357, // <channel> :End of Channel Invite List IRCNET
RplExceptList = 348, // <channel> <exception> <nick> <time> IRCNET
RplEndOfExceptList = 349, // <channel> :End of Channel Exception List IRCNET
RplBanList = 367, // <channel> <ban> <nick> <time>
RplEndOfBanList = 368, // <channel> :End of Channel Ban List
// server/misc
RplVersion = 351, // <version>.<debug> <server> :<info>
RplInfo = 371, // :<info>
RplEndOfInfo = 374, // :End of /INFO list.
RplYoureOper = 381, // :You are now an IRC Operator
RplRehashing = 382, // <file> :Rehashing
RplYoureService = 383,
RplTime = 391, // <server> :<time>
RplUsersStart = 392,
RplUsers = 393,
RplEndOfUsers = 394,
RplNoUsers = 395,
RplServList = 234,
RplServListEnd = 235,
RplAdminMe = 256, // :Administrative info about server
RplAdminLoc1 = 257, // :<info>
RplAdminLoc2 = 258, // :<info>
RplAdminEMail = 259, // :<info>
RplTryAgain = 263, // :Server load is temporarily too heavy. Please wait a while and try again.
// tracing
RplTraceLink = 200,
RplTraceConnecting = 201,
RplTraceHandshake = 202,
RplTraceUnknown = 203,
RplTraceOperator = 204,
RplTraceUser = 205,
RplTraceServer = 206,
RplTraceService = 207,
RplTraceNewType = 208,
RplTraceClass = 209,
RplTraceReconnect = 210,
RplTraceLog = 261,
RplTraceEnd = 262,
// stats
RplStatsLinkInfo = 211, // <connection> <sendq> <sentmsg> <sentbyte> <recdmsg> <recdbyte> :<open>
RplStatsCommands = 212, // <command> <uses> <bytes>
RplStatsCLine = 213, // C <address> * <server> <port> <class>
RplStatsNLine = 214, // N <address> * <server> <port> <class>
RplStatsILine = 215, // I <ipmask> * <hostmask> <port> <class>
RplStatsKLine = 216, // k <address> * <username> <details>
RplStatsPLine = 217, // P <port> <??> <??>
RplStatsQLine = 222, // <mask> :<comment>
RplStatsELine = 223, // E <hostmask> * <username> <??> <??>
RplStatsDLine = 224, // D <ipmask> * <username> <??> <??>
RplStatsLLine = 241, // L <address> * <server> <??> <??>
RplStatsuLine = 242, // :Server Up <num> days, <time>
RplStatsoLine = 243, // o <mask> <password> <user> <??> <class>
RplStatsHLine = 244, // H <address> * <server> <??> <??>
RplStatsGLine = 247, // G <address> <timestamp> :<reason>
RplStatsULine = 248, // U <host> * <??> <??> <??>
RplStatsZLine = 249, // :info
RplStatsYLine = 218, // Y <class> <ping> <freq> <maxconnect> <sendq>
RplEndOfStats = 219, // <char> :End of /STATS report
RplStatsUptime = 242,
// GLINE
RplGLineList = 280, // <address> <timestamp> <reason> UNDERNET
RplEndOfGLineList = 281, // :End of G-line List UNDERNET
// Silence
RplSilenceList = 271, // <nick> <mask> UNDERNET/DALNET
RplEndOfSilenceList = 272, // <nick> :End of Silence List UNDERNET/DALNET
// LUser
RplLUserClient = 251, // :There are <user> users and <invis> invisible on <serv> servers
RplLUserOp = 252, // <num> :operator(s) online
RplLUserUnknown = 253, // <num> :unknown connection(s)
RplLUserChannels = 254, // <num> :channels formed
RplLUserMe = 255, // :I have <user> clients and <serv> servers
RplLUserLocalUser = 265, // :Current local users: <curr> Max: <max>
RplLUserGlobalUser = 266, // :Current global users: <curr> Max: <max>
// Errors
ErrNoSuchNick = 401, // <nickname> :No such nick
ErrNoSuchServer = 402, // <server> :No such server
ErrNoSuchChannel = 403, // <channel> :No such channel
ErrCannotSendToChan = 404, // <channel> :Cannot send to channel
ErrTooManyChannels = 405, // <channel> :You have joined too many channels
ErrWasNoSuchNick = 406, // <nickname> :There was no such nickname
ErrTooManyTargets = 407, // <target> :Duplicate recipients. No message delivered
ErrNoColors = 408, // <nickname> #<channel> :You cannot use colors on this channel. Not sent: <text> DALNET
ErrNoOrigin = 409, // :No origin specified
ErrNoRecipient = 411, // :No recipient given (<command>)
ErrNoTextToSend = 412, // :No text to send
ErrNoTopLevel = 413, // <mask> :No toplevel domain specified
ErrWildTopLevel = 414, // <mask> :Wildcard in toplevel Domain
ErrBadMask = 415,
ErrTooMuchInfo = 416, // <command> :Too many lines in the output, restrict your query UNDERNET
ErrUnknownCommand = 421, // <command> :Unknown command
ErrNoMotd = 422, // :MOTD File is missing
ErrNoAdminInfo = 423, // <server> :No administrative info available
ErrFileError = 424,
ErrNoNicknameGiven = 431, // :No nickname given
ErrErroneusNickname = 432, // <nickname> :Erroneus Nickname
ErrNickNameInUse = 433, // <nickname> :Nickname is already in use.
ErrNickCollision = 436, // <nickname> :Nickname collision KILL
ErrUnAvailResource = 437, // <channel> :Cannot change nickname while banned on channel
ErrNickTooFast = 438, // <nick> :Nick change too fast. Please wait <sec> seconds. (most)
ErrTargetTooFast = 439, // <target> :Target change too fast. Please wait <sec> seconds. DALNET/UNDERNET
ErrUserNotInChannel = 441, // <nickname> <channel> :They aren't on that channel
ErrNotOnChannel = 442, // <channel> :You're not on that channel
ErrUserOnChannel = 443, // <nickname> <channel> :is already on channel
ErrNoLogin = 444,
ErrSummonDisabled = 445, // :SUMMON has been disabled
ErrUsersDisabled = 446, // :USERS has been disabled
ErrNotRegistered = 451, // <command> :Register first.
ErrNeedMoreParams = 461, // <command> :Not enough parameters
ErrAlreadyRegistered= 462, // :You may not reregister
ErrNoPermForHost = 463,
ErrPasswdMistmatch = 464,
ErrYoureBannedCreep = 465,
ErrYouWillBeBanned = 466,
ErrKeySet = 467, // <channel> :Channel key already set
ErrServerCanChange = 468, // <channel> :Only servers can change that mode DALNET
ErrChannelIsFull = 471, // <channel> :Cannot join channel (+l)
ErrUnknownMode = 472, // <char> :is unknown mode char to me
ErrInviteOnlyChan = 473, // <channel> :Cannot join channel (+i)
ErrBannedFromChan = 474, // <channel> :Cannot join channel (+b)
ErrBadChannelKey = 475, // <channel> :Cannot join channel (+k)
ErrBadChanMask = 476,
ErrNickNotRegistered= 477, // <channel> :You need a registered nick to join that channel. DALNET
ErrBanListFull = 478, // <channel> <ban> :Channel ban/ignore list is full
ErrNoPrivileges = 481, // :Permission Denied- You're not an IRC operator
ErrChanOPrivsNeeded = 482, // <channel> :You're not channel operator
ErrCantKillServer = 483, // :You cant kill a server!
ErrRestricted = 484, // <nick> <channel> :Cannot kill, kick or deop channel service UNDERNET
ErrUniqOPrivsNeeded = 485, // <channel> :Cannot join channel (reason)
ErrNoOperHost = 491, // :No O-lines for your host
ErrUModeUnknownFlag = 501, // :Unknown MODE flag
ErrUsersDontMatch = 502, // :Cant change mode for other users
ErrSilenceListFull = 511 // <mask> :Your silence list is full UNDERNET/DALNET
}; // eo enum Reply
{var%20f='http://v.t.sina.com.cn/share/share.php?appkey=1515056452',u=z||d.location,p=['&url=',e(u),'&title=',e(t||d.title),'&source=',e(r),'&sourceUrl=',e(l),'&content=',c||'gb2312','&pic=',e(p||'')].join('');function%20a(){if(!window.open([f,p].join(''),'mb',['toolbar=0,status=0,resizable=1,width=440,height=430,left=',(s.width-440)/2,',top=',(s.height-430)/2].join('')))u.href=[f,p].join('');};if(/Firefox/.test(navigator.userAgent))setTimeout(a,0);else%20a();})(screen,document,encodeURIComponent,'','','https://img.manongdao.com/sparkler-677774__340.jpg', '推荐 狗以群分 的文章《Trying to write an IRC client but struggling to fi》','https://www.manongdao.com/article-628779.html','页面编码gb2312|utf-8默认gb2312'));){kind=link}