getProtocolByName

[dominic.j.steinitz@britishairways.com]

Here's my test program. TCP is a valid protocol. But I get the following
when I run it. I'm running under W98 by the way. I have two questions:

1) Why do I get an error?
2) Even if this is a valid error why doesn't the function tell me so that I
can handle it rather than terminating?

Dominic.

C:\Dom\haskell\ping>main

Fail: does not exist
Action: getProtocolByName
Reason: no such protocol entry

C:\Dom\haskell\ping>version

C:\Dom\haskell\ping>"c:\program files\glasgow haskell
compiler\ghc-5.02\bin\ghc"
 --version
The Glorious Glasgow Haskell Compilation System, version 5.02


module Main(main) where

import BSD

main =
   do protocolEntry <- getProtocolByName "TCP"
      {- The documentation gives no clue as to what
         constitutes an error condition. Looking at the
         C equivalent in
         http://www.opengroup.org/onlinepubs/7908799/xns/endprotoent.html,
         this gives a null pointer to the
         data structure. Assume for now that the Haskell
         equivalent returns a null protocol name. -}
      if protoName protocolEntry == ""
         then putStrLn "Error"
         else putStrLn ("Protocol name: " ++ (protoName protocolEntry))