[Haskell-cafe] Network.Socket Woes

Scott Bell sebell at gmail.com
Fri Mar 7 12:56:32 EST 2008


Adam,

This does the trick, thanks! I certainly would not have been
able to track down such an insidious `issue' without much
agony and despair.

- Scott

On Fri, Mar 7, 2008 at 10:48 AM, Adam Langley <agl at imperialviolet.org> wrote:
> On Fri, Mar 7, 2008 at 8:10 AM, Scott Bell <sebell at gmail.com> wrote:
> >  my test program. The Haskell version, however, does not
> >  return from recvFrom. I've also tried wrapping this in a
> >  withSocketsDo, with no effect.
>
> So this is a long standing, ah, issue with the Network modules.
>
> Try sending a UDP packet to port 45607 and you'll find that the
> Haskell code gets it.
>
> hex(45607) = 0xb227
> 0x27b2 = 10162
>
> In short, PortNum doesn't do the endian conversion for you. And I
> don't know a good way to figure out the endianness of the underlying
> system from Haskell I'm afraid. I usually end up FFIing out to htons
> or just assuming that the system is little-endian.
>
> We should really fix this unless there's some trick that I've been
> missing all this time.
>
>
> AGL
>
> --
> Adam Langley agl at imperialviolet.org http://www.imperialviolet.org
>


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