[Haskell-cafe] How to return a network connection to C

[Donn Cave]

Quoth C K Kashyap <ckkashyap at gmail.com>,

> I am using http://hackage.haskell.org/package/connection.
> So I create network connection in Haskell
>
> getConnection :: IO Connection
>
> I'd like this connection to be returned to C so that subsequent calls from
> C can send in the connection handle.

According to the documentation, he doesn't export enough of the
Connection type to access the handle inside, and there appears to
be no function provided to do that either.  So it looks to me like
you'd have to 1) make the connection "by hand" with Network.Socket.connect
etc., 2) get the Socket fd, 3) make a Handle from the Socket,
4) pass that to connectFromHandle, and 5) use the fd with your
C function.

Note that the socket connection itself, represented by the fd that
you return to C, will simply transmit data back and forth without
modification.  Specifically without SSL encryption.  If you need
SSL encryption in both Haskell and C, it would probably be simpler
to implement the I/O in C and call it from Haskell.

	Donn