[Haskell-cafe] system in forkIO

[Don Stewart]

marcot:
> Em Dom, 2008-09-14 às 16:07 -0300, Marco Túlio Gontijo e Silva escreveu:
> > Thanks, I got it to work running 
> > 
> > threadWaitRead stdInput
> > 
> > before getChar.
> 
> Now I've got another problem:
> 
> > import Control.Concurrent
> > import System.IO
> > import System.Process
> 
> > main :: IO ()
> > main
> >   = do
> >     process <- runCommand "wget
> http://ftp.br.debian.org/debian/pool/main/g/ghc6/ghc6_6.8.2-6_amd64.deb"
> >     forkIO
> >       $ putStrLn "fork"
> >       >> getChar >>= putChar
> >       >> terminateProcess process
> >     waitForProcess process
> >     return ()
> 
> Not even fork is shown.  Any hints?

Daemonic threads. When the main thread exits, everything exits. Check
the docs for Control.Concurrent.

You better use an MVar to ensure the main thread waits on its child.

-- Don