Re: [Haskell-cafe] Can't figure out source of race condition when using System.Process

2 Nov 2008

      On Mon, Nov 03, 2008 at 01:02:12AM +1100, Rafal Kolanski wrote:
...
Rafal Kolanski.
-- Pass text to md5sum and drop the final "  -" when returning
hashMD5 text = do
    (inp,out,err,pid) <- runInteractiveProcess "md5sum" [] Nothing Nothing
    forkIO $ do 
        hPutStrLn inp text
        hClose inp
    exit <- waitForProcess pid
    case exit of ExitFailure _ -> error "md5sum fail" 
                 _ -> return ()
[...]
Why do you use forkIO here? It's not necessary. The process will run in
background on its own. ?

It would help me tracking the problem down having a full compilable
example..

Sincerly
Marc Weber