It might be easier to use bytestrings instead of Ptr (). I think the
relevant function is hGetNonBlocking[1].
Cheers,
Michael
[1] http://hackage.haskell.org/packages/archive/bytestring/0.9.1.7/doc/html/Data...
On Thu, Sep 23, 2010 at 7:13 PM, Patrick LeBoutillier
Hi ,
I'm trying to write a toy generic network proxy that will accept connections on a port, and for each connection connect to a remote server and forward the traffic.
Here's what I have do far:
import Network import System.IO import Control.Exception import Control.Concurrent
copy :: Handle -> Handle -> IO () copy a b = undefined
redir :: Handle -> Handle -> IO () redir h1 h2 = forkIO (copy h1 h2) >> forkIO (copy h2 h1) >> return ()
acceptLoop :: Socket -> HostName -> PortID -> IO () acceptLoop sock rhost rport = loop where loop = do (local, host, port) <- accept sock remote <- connectTo rhost rport redir local remote loop >> return ()
main = do let local_port = 8000 let remote_host = "whatever" let remote_port = 80 server <- listenOn (PortNumber local_port) acceptLoop server remote_host (PortNumber remote_port)
Basically I'm stuck at how to implement the copy function. I want it to block until some data is available on a, read it and then write it to b.
I think I need to use hGetBufNonBlocking, but I don't know how to get a "Ptr a".
I am on the right track with this?
Patrick -- ===================== Patrick LeBoutillier Rosemère, Québec, Canada _______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners