This document explains how to write an interface for DCPlus 3.0. DCPlus version
   3 has a seperate communications interface for server to client and client to
   client communications and should act as a object oriented environment.
  Objects are represented by a single character representing the object class and
   the object identifier. If the hub supports DCPlus 3.0, it represents itself
   as M:local or M:me. For backward compatibility purposes, it is recommended
   that most clients use M:me.
  Hubs with DCPlus 3.0 support MUST send this command when a user connects or

   sends $GetNickList:
    $Hello $DCPlus|
  If a hub previously did NOT have DCPlus support and wishes to enable it, the
   hub should send all clients the above command also.
  If a hub previously had DCPlus 3.0 support and wishes to disable it, it must
   send to all clients:
    $Quit $DCPlus|
  A hub may choose to disable DCPlus support for users who are not using DCPlus
   3.0 compatible clients. In no case should a hub initialize a conversation with
   a client which does not support DCPlus 3.0.


  Clients which support DCPlus 3.0 are represented by U: plus the username that
   the client is logged onto the current hub as. To enable DCPlus 3.0, a client
   must set Bit 4 (1-based) in the connection flag byte. This can easilly be
   accomplished by applying an OR 0x10 operation to the normal connection flag
   byte. For informational purposes, the connection flag byte referred to here is
   located at the * in the following command:
    $MyINFO $ALL bakanick nothin$ $Magic Wire*$$0$|

  For a hub to send a command to a client, it should format it as seen below:
    $To: ClientsUsername From: $DCPlus $<$DCPlus> Command-And-Parameters|
  For a client to send a command to the hub, it should format it as seen below:

    $To: $DCPlus From: ClientsUsername $<ClientsUsername> Command-And-Parameters|
  For a client to send a command to another client, it should send to the hub:
    $To: OtherClientUsername From: ClientsUsername $<ClientsUsername> *Cmd&Params|
  In the above line, the client MUST replace * with ASCII character code number 4.
   If a user on the client wishes to PM a message starting with a real character
   number 4 in a message, the client should escape it with a \ (only if dest
   user is DCPlus 3). Therefore when a message starting with \* (*=asc chr 4) is
   received from a DCPlus 3 client, it should remove the \ from the start of the
   message.

  For a DCPlus supporting client to send a command to ALL DCPlus users, they

   should use the following command:
    $Search 0:0 F*?F*?0*?9*?DCPlus/Command-And-Parameters|

  For certain commands which can be sent via "SR UDP", they must be sent in the
   following command:
    $DCPlus Command-And-Parameters|

  Parameters are a single word long. To include spaces in a parameter, the entire
   parameter must be enclosed in double quotes ("). Double quote and backslash
   characters within an enclosed parameter must be escaped by a backslash. For
   example: \" or \\

  Below, <A> to <Z> are required arguments, [A] to [Z] are optional arguments,
   and [@] refers to whatever extra data is there.
  *in the case of a $Search usage, the $Search command may specific values for
   'maxsize', 'minsize', and 'filetype'.

  Hub to Client commands are:
    SetOption ReserveSlots <A> [B]
      <A> is the number of slots to reserve for users on this hub. Reply via
       OptionSet required. [B] is response code.
    SetOption DisCloseDownload <A> [B]
      If <A> is non-zero then the client should close all downloads from users

       in the current hub when the user leaves that hub. For example, if UserA
       downloads from UserB in HubB and then leaves HubB, UserA's download is
       cut. If <A> is a non-negative number, the client may wait <A> minutes
       before cutting the downloads. Reply via OptionSet required. [B] is
       response code.
    Error <A> [@]
      <A> is the command that caused the error. If present, [@] has more
       details.
    UserIP <A> <B> [C]
      Informs the client that <B> is the IP of <A>. [C] is a flag set by the
       request command.

    Success <A> [@]
      <A> is the command that succeeded and [@] might have more details.
    GotProp <A> <B> <C>
      Optional backward compatibility for DCPlus 2.0. See 2.0 docs for details.
    CmdOk [@] [@] [...]
      Arguments are a list of supported (or unsupported) commands. Supported
       commands should be prefixed with a + and unsupported by a -.
    PageCount <A>
      <A> is the number of pages waiting for the client's username
    PageMsg <A> <@>
      <A> is the user who the page is from and <@> is the page message.

    HelpStart <A> <B>
      <A> is the page id code and <B> is the response code.
    HelpData <A> <B>
      <A> is the response code and <B> is the line of data.
    HelpEnd <A>
      <A> is the response code.
    Ping [A]
      [A] is the response code. A reply should be sent back via Pong ASAP.
    Pong [A]
      [A] is the response code. This should be sent when a Ping is received.
    Cmd [@] [@] [...]

      Arguments are specific commands to check for. If none are present, a full
       list of supported commands is returned. Reply is via CmdOk reply.
    RegisterOk <A>
      <A> is the response code. This is a reply to RegisterNick.
    RegisterDenied <A>
      <A> is the response code. This is similar to a permission denied for
       RegisterNick.
    OptionSet <A> [B] <C>
      <A> is the option that was set. [B] is the new value. <C> is replycode
    ListOptions [A] [@] [@] [...]
      [A] is a reply code. The arguments are what commands to look for. If no

       arguments (besides [A]), all commands will be returned.
    OptionList [A] [@] [@] [...]
      [A] is a reply code. The arguments are the options supported. If an
       option is listed but not supported, it should appear in brackets ('[]')
  Client to Hub Commands are:
    GetIP [@] [@] [...]
      Arguments are the usernames to get the IPs of. Result is sent back via
       UserIP responses.
    GetIP+ [A] [@] [@] [...]
      Arguments are the usernames to get the IPs of. Result is sent back via
       UserIP responses. [A] is the response code.

    Boot [@] [@] [...]
      Arguments are the usernames to boot. There is no reply.
    BanMAC <A>
      <A> is the MAC address to ban. There is no reply.
    UnBanMAC [A] [@] [@] [...]
      [A] is the response code. The arguments after it are MACs to unban. There
       should be a 'Success/Error UnBanMAC [A]' reply.
    BanIP <A>
      <A> is the IP address to ban. There is no reply.
    UnBanIP [A] [@] [@] [...]
      [A] is the response code. The arguments after it are IPs to unban. There

       should be a 'Success/Error UnBanIP [A]' reply.
    Kick <A>
      <A> is the user to kick. There is no reply.
    TempBanIP <A>
      <A> is the IP address to temp ban. There is no reply.
    UnTempBanIP [A] [@] [@] [...]
      [A] is the response code. The arguments after it are IPs to un temp ban.
       There should be a 'Success/Error UnTempBanIP [A]' reply.
    BanName [@] [@] [...]
      Arguments are usernames to ban usage of. There is no reply.
    UnBanName [A] [@] [@] [...]

      [A] is the response code. The arguments after it are names to unban. There
       should be a 'Success/Error UnBanName [A]' reply.
    Ban <A>
      <A> is the username of the user to ban (in any method). There is no reply
    GetProp <A> <B>
      Optional backward compatibility for DCPlus 2.0. See 2.0 docs for details.
    PutProp <A> <B> <C>
      Optional backward compatibility for DCPlus 2.0. See 2.0 docs for details.
    AppProp <A> <B> <C>
      Optional backward compatibility for DCPlus 2.0. See 2.0 docs for details.
    RitProp <A> <B> <C>

      Optional backward compatibility for DCPlus 2.0. See 2.0 docs for details.
    Cmd [@] [@] [...]
      Arguments are specific commands to check for. If none are present, a full
       list of supported commands is returned. Reply is via CmdOk reply.
    MassMsg [@]
      [@] is the message to mass-announce. No reply.
    SendPage <A> [@]
      <A> is the user to send a page to. [@] is the message.
    GetPage [A]
      [A] is the message number to retrieve. If present, message is sent to
       client via PageMsg reply and the message is deleted from the hub. If

       not, number of messages is sent to client via PageCount reply.
    PeekPage <A>
      <A> is the message number to retrieve. Message should be sent via PageMsg
       reply and the message SHOULD NOT BE DELETED FROM HUB.
    HelpOn <A> [B]
      <A> is the help id code. If present, [B] is the response code.
    Ping [A]
      [A] is the response code. A reply should be sent back via Pong ASAP.
    Pong [A]
      [A] is the response code. This should be sent when a Ping is received.
    OptionSet <A> [B] <C>

      <A> is the option which was set correctly. <B> is the new value. This is
       a reply to the SetOption command.
    CmdOk [@] [@] [...]
      Arguments are a list of supported (or unsupported) commands. Supported
       commands should be prefixed with a + and unsupported by a -.
    RegisterNick <A> <B>
      <A> is the password to register the nickname with. <B> is a response code
    SetOption Topic <A> [B]
      <A> is the new hub topic/name. [B] is response code.
    SetOption Chat.<A> <B> [C]
      <A> is the username of the client to affect. If <B> is zero, chat

       messages should no longer be sent to the client. [C] is the response
       code. 'SetOption Chat <B> [C]' affects the client sending the command
    SetOption Userlist.<A> <B> [C]
      <A> is the username of the client to affect. If <B> is zero, userlist
       updates should no longer be sent to the client. [C] is the response
       code. 'SetOption Userlist <B> [C]' affects the client sending command
    SetOption Search.<A> <B> [C]
      <A> is the username of the client to affect. If <B> is zero, searches
       should no longer be sent to the client. [C] is the response code.
       'SetOption Search <B> [C]' affects the client sending the command
      Note: It is recommended that hubs put bot restrictions on this.

    SetOption Visible.<A> <B> [C]
      <A> is the username of the client to affect. If <B> is non-zero, then
       user should be kept off the userlist. [C] is the response code.
       'SetOption Visible <B> [C]' affects the client sending the command
      Note: It is recommended that hubs put bot restrictions on this.
    SetOption BlockConnects.<A> <B> [C]
      <A> is the username of the client to affect. If <B> is non-zero, then
       hub should prevent [Rev]ConnectToMe commands from reaching the client.
       [C] is the response code. 'SetOption BlockConnects <B> [C]' affects
       the client sending the command
      Note: It is recommended that hubs put bot restrictions on this.

    ListOptions [A] [@] [@] [...]
      [A] is a reply code. The arguments are what commands to look for. If no
       arguments (besides [A]), all commands will be returned.
    OptionList [A] [@] [@] [...]
      [A] is a reply code. The arguments are the options supported. If an
       option is listed but not supported, it should appear in braces ('{}')
  Client to Client commands are:
    Ping [A]
      [A] is the response code. A reply should be sent back via Pong ASAP.
    Pong [A]
      [A] is the response code. This should be sent when a Ping is received.

    IsPassive [A]
      [A] is the response code. The client should reply with MyModeIs.
    MyModeIs <A> [B]
      If <A> is non-zero, the user is passive. [B] is the response code.
    SendFile <A> [B]
      <A> is the URI of where the file can be received. [B] = replycode
       Example: DC1C://bakausername:apassword@my.hostname.com/folder/file.exe
    RefuseURI [B]
      [B] is the reply code.
    ProtocolOk <A> [B]
      <A> is the protocol. [B] is the reply code. Reply via ICProtocol cmd.

    ICProtocol <A> <B> [C]
      <A> is the protocol. <B> is non-zero if it is supported. [C] is replycode
    ProtocolsAre [A]
      [A] is the reply code. Response is via ICProtocol command.
    ExternChat <A> [B]
      <A> is the URI to chat with. [B] is the response code.
       Example of <A>: telnet://my.hostname.net:2222
    NetGame <A> [B]
      <A> is the URI of where to meet for a game. [B] is the response code.
       Example of <A>: armagetron://games.secret.com.au/
           snes9x://my.hostname.org:1998/

    NetApp <A> [B]
      <A> is the URI. [B] is the response code.
    FindFile <A> <B> [@]/[@]/[...]
      <A> is either host:port or "Hub:"+username. <B> is the response code.
       [1] is the minimum file size. [2] is the file type (see DC1 protocol
       specs for more info). [3] is the maximum file size. The [@] arguments
       are sets of option=value. If a client does not recognize an option it
       should ignore the FindFile command and NOT continue. If the unrecognized
       option is enclosed in braces then the client should ignore the option
       and do a Find without it. For example:
       'FindFile Hub:baka 0 md5=9291047/{id3v2_title}=sing$filename' would

       cause a client to search for a file with 'filename' in the actual
       filename and MD5 of '9291047'. If the client understands the
       id3v2_title option, it will only return results that match it. If not,
       it returns results regardless of the id3v2_title option. If the client
       doesn't understand the md5 option it will not search at all and will not
       return any search results. See post-command info for standard options.
       Note: option and value pairings can be o=v o>v o<v o>=v o<=v or o!=v
       Note: option and value names with non-alphanumeric characters must be
             escaped with % followed by 2 hex characters.
       Note: This command may be sent via SR UDP.
    FileFound <A> [B] [@]

      <A> is the response code. [B] is detailed information about the file in
       option=value format with / as a delimiter. [@] is the data for the SR
       standard command. See DC1 protocol specs for more info.
       Note: option and value pairings can be o=v o>v o<v o>=v o<=v or o!=v
       Note: option and value names with non-alphanumeric characters must be
             escaped with % followed by 2 hex characters.
       Note: This command may be sent via SR UDP.
    PrivMsg [A] <B> [@]
      [A] is the host:port of a common hub. This field may be skipped. <B> is
       the username who the PrivMsg is sent by. [@] is the actual message.
       Note: This command may be sent via SR UDP

    ConnectToMe <A> [B] [C]
      <A> is host:port of the user. If [B] is present and non-zero, the
       sender is the one who will upload. Otherwise, the sender downloads.
       If present, [C] is the protocol identifier to use. If not present, the
       DC1C protocol will be used. Note: this command may be sent via SR UDP
    RevConnectToMe <A> [B]
      <A> is the username. Send a ConnectToMe back with a non-zero 2nd argument
       If present, [B] is the protocol to use for the connection.
    Cmd [@] [@] [...]
      Arguments are specific commands to check for. If none are present, a full
       list of supported commands is returned. Reply is via CmdOk reply.

       Note: this command may be sent via SR UDP
    CmdOk [@] [@] [...]
      Arguments are a list of supported (or unsupported) commands. Supported
       commands should be prefixed with a + and unsupported by a -.
       Note: this command may be sent via SR UDP
    OptionSet <A> [B] <C>
      <A> is the option that was set. [B] is the new value. <C> is replycode
    ListOptions [A] [@] [@] [...]
      [A] is a reply code. The arguments are what commands to look for. If no
       arguments (besides [A]), all commands will be returned.
    OptionList [A] [@] [@] [...]

      [A] is a reply code. The arguments are the options supported. If an
       option is listed but not supported, it should appear in brackets ('[]')
    Finger <A> [B] [C]
      <A> is a reply code. If present, [B] is the return path for the response.
       If present, [C] is a specific FingerInfo name to get: No other fields
       should be returned.
       Note: this command may be sent via SR UDP
    FingerInfo <A> [@]
      <A> is a reply code. [@] is the finger data in the format of:
       name=value/name=value/n=v/etc (similar to FindFile options)
       See below for common FingerInfo names. Note: this command may be sent

       via SR UDP   

  Standard FindFile options:
    md5
      A MD5 hash of the file.
    exactname
      Specifies that the filename specified is exact (not within)
    id3v2_title
      The title of the ID3v2 file
    id3v2_copyright
      Non-Zero if the ID3v2 file is copyrighted

    media_length
      Length of WAV/MP3/Video
    avi_fourcc
      FOURCC code of the AVI video
    video_width
      Width of the video in pixels
    video_height
      Height of the video in pixels
    video_pixels
      Width*Height of the video in pixels
    audio_bitrate

      Bitrate of audio (kbit/s)
    video_bitrate
      Bitrate of video (kbit/s)
    audio_channels
      Number of audio channels (1=Mono; 2=Stereo)
    audio_hz
      Hz of audio
    minsize
      Minimum filesize (overrides everything else)
    maxsize
      Maximum filesize (overrides everything else)

    filetype
      'audio', 'video', etc (overrides all else)

  Standard FingerInfo options:
    EMail
    IM-Jabber
    IM-AIM
    IM-ICQ
    IM-.NET
      Formerly known as MSN
    IM-Yahoo

      (USA)
    IM-YahooJP
      (Japan)
    URI-Homepage
    URI-Link
    Birthdate
    Comment
      (usually the DC 'Content Info' field)
    Code-Geek
      GeekCode
    Code-Moonie

      MoonieCode