GMCP_handler.xml

<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE muclient>

<muclient>

<plugin
   name="GMCP_handler"
   author="Nick Gammon"
   id="74f8c420df7d59ad5aa66246"
   language="Lua"
   purpose="Handle GMCP messages and broadcast data"
   save_state="y"
   date_written="2015-05-06"
   requires="4.59"
   version="1.0"
>
<description trim="y">

  GMCP handler for Aardwolf and IRE MUDs.
  
  Type: 'gmcpdebug 1' for debugging info.
  Type: 'gmcpdebug 0' to turn debugging off.

</description>

</plugin>

<aliases>
<alias
   script="gmcpdebug"
   match="^gmcpdebug (.*)?$"
   enabled="y"
   regexp="y"
   sequence="100"
   ignore_case="y"
></alias>

</aliases>


<script>
<![CDATA[
local IAC, SB, SE, DO = 0xFF, 0xFA, 0xF0, 0xFD
local GMCP      = 201
local GMCPDebug = tonumber(GetVariable("GMCPDebug")) or 0
function gmcpdebug(name, line, wildcards)
   newval = tonumber(wildcards[1])
   if not newval or newval > 2 or newval < 0 then
      ColourNote("darkorange", "", "GMCPDebug valid values are: 0 - off, 1 - simple, 2 - verbose")
      return
   end
   GMCPDebug = newval
   local msg = "off"
   if GMCPDebug == 1 then
      msg = "simple"
   elseif GMCPDebug == 2 then
      msg = "verbose"
   end
   ColourNote ("darkorange", "", "GMCPDebug: " .. msg)
end
 
---------------------------------------------------------------------------------------------------
-- Mushclient callback function when telnet SB data received.
---------------------------------------------------------------------------------------------------
function OnPluginTelnetSubnegotiation (msg_type, data)
   if msg_type ~= GMCP then
      return
   end -- if not GMCP
  
   -- debugging
   if GMCPDebug > 0 then 
     ColourNote ("darkorange", "", data) 
   end
   message, params = string.match (data, "([%a.]+)%s+(.*)")
  
   -- if valid format, broadcast to all interested plugins
   if message then
     BroadcastPlugin(1, data)
   end -- if
   
end -- function OnPluginTelnetSubnegotiation
function OnPluginSaveState()
   SetVariable("GMCPDebug", GMCPDebug)
end
function OnPluginTelnetRequest (msg_type, data)
   if msg_type == GMCP and data == "WILL" then
      return true
   end -- if
  
   if msg_type == GMCP and data == "SENT_DO" then
      Note ("Enabling GMCP.") 
      -- This hard-coded block may need to be made into a config table as we add more message types.
      Send_GMCP_Packet (string.format ('Core.Hello { "client": "MUSHclient", "version": "%s" }', Version()))
      Send_GMCP_Packet ('Core.Supports.Set [ "Char 1", "Comm 1", "Room 1" ]')
      return true
   end -- if GMCP login needed (just sent DO)
   return false
end -- function OnPluginTelnetRequest
function OnPluginDisable()
   EnablePlugin(GetPluginID(), true)
   ColourNote("white", "blue", "You are not allowed to disable the "..
   GetPluginInfo(GetPluginID(), 1).." plugin. It is necessary for other plugins.")
end
---------------------------------------------------------------------------------------------------
-- Helper function to send GMCP data.
---------------------------------------------------------------------------------------------------
function Send_GMCP_Packet (what)
   assert (what, "Send_GMCP_Packet passed a nil message.")
   SendPkt (string.char (IAC, SB, GMCP) .. 
           (string.gsub (what, "\255", "\255\255")) ..  -- IAC becomes IAC IAC
            string.char (IAC, SE))
end -- Send_GMCP_Packet
]]>
</script>
</muclient>