I've progressed further - now the VNC client opens up a window with the dimensions set in the code! https://github.com/ckkashyap/LearningPrograms/blob/master/Haskell/vnc/vnc.hs I've pasted the code here for quick reference - would really appreciate some feedback. module Main where import Network.Server import Network.Socket import Control.Monad import System.IO import qualified Data.ByteString.Lazy as BS import Data.Char import Data.Binary.Get import Data.Binary.Put import Data.Word main :: IO () main = do running <- serveOne (Just $ UserWithDefaultGroup "ckk") server putStrLn "server is accepting connections!!!" waitFor running where server = Server (SockAddrInet 5901 iNADDR_ANY) Stream doVNC doVNC :: ServerRoutine doVNC (h,n,p) = do startRFB h startRFB :: Handle -> IO () startRFB h = do hPutStr h "RFB 003.003\n" hFlush h clientHeaderByteStream <- BS.hGet h 12 putStrLn (show clientHeaderByteStream) let (m,n) = ( runGet readClientHeader clientHeaderByteStream) -- Send 1 to the client, meaning, no auth required BS.hPutStr h (BS.pack [0,0,0,1]) hFlush h clientInitMessage <- BS.hGet h 1 let sharedOrNot = runGet (do {x<-getWord8;return(x);}) clientInitMessage putStrLn (show sharedOrNot) BS.hPutStr h serverInitMessage hFlush h serverInitMessage :: BS.ByteString serverInitMessage = runPut $ do putWord16be (300::Word16) -- width putWord16be (300::Word16) -- height --pixel format putWord8 (32::Word8) -- bits per pixl putWord8 (24::Word8) -- depth putWord8 (1::Word8) -- big endian putWord8 (1::Word8) -- true color putWord16be (255::Word16) -- red max putWord16be (255::Word16) -- green max putWord16be (255::Word16) -- blue max putWord8 (24::Word8) -- red shift putWord8 (1::Word8) -- green shift putWord8 (1::Word8) -- blue shift --padding putWord8 (0::Word8) putWord8 (0::Word8) putWord8 (0::Word8) --name length let name = "Haskell Framebuffer" putWord32be (((fromIntegral.length) name)::Word32) putLazyByteString (stringToByteString name) byteString2Number :: BS.ByteString -> Int byteString2Number bs = _byteString2Number 1 (digits bs) where _byteString2Number _ [] = 0 _byteString2Number n (x:xs) = (n*x) + (_byteString2Number (n*10) xs) digits bs = map ((+(-48)).fromIntegral) (BS.unpack(BS.reverse bs)) readClientHeader = do getLazyByteString 4 m <- getLazyByteString 3 getWord8 n <- getLazyByteString 3 getWord8 let majorVersionNumber = byteString2Number m let minorVersionNumber = byteString2Number n if (majorVersionNumber /= 3) then fail ("ERROR: Unsupported version " ++ (show majorVersionNumber)) else return (byteString2Number m,byteString2Number n) word8ToByteString :: Word8 -> BS.ByteString word8ToByteString n = runPut $ putWord8 n word16ToByteString :: Word16 -> BS.ByteString word16ToByteString n = runPut $ putWord16be n word32ToByteString :: Word32 -> BS.ByteString word32ToByteString n = runPut $ putWord32be n stringToByteString :: String -> BS.ByteString stringToByteString str = BS.pack (map (fromIntegral.ord) str) On Thu, Nov 4, 2010 at 12:18 PM, C K Kashyap wrote:

Hi,

I started with the implementation of a VNC server library intended to be used as a library for rendering graphics and interacting with the user(mouse/keyboard). I'd appreciate it very much if I could  get some feedback on my approach to binary parsing and Haskellism. Also, any reference/suggestion on how I could go about using a state machine to deal with the RFB protocol.

http://hpaste.org/41131/vnc_server

It's really early - but just wanted to get some advice on the approach.

-- Regards, Kashyap

-- Regards, Kashyap