[Haskell-cafe] program execution and laziness

[Henning Thielemann]

On Wed, 13 Sep 2006, Tim Newsham wrote:

> I'm having a problem with program execution in win32 which seems
> to be tied to laziness.  The function I'm using is:
> 
> runCmd cmd outdir dir base ext = do
>     let argv = words cmd
>     (i,o,e,p) <- runInteractiveProcess (head argv) (drop 1 argv) Nothing
> Nothing
>     hClose i
>     out <- hGetContents o
>     -- print out
>     x <- waitForProcess p
>     hClose o
>     hClose e
>     case x of
>         ExitSuccess      -> return 0
>         (ExitFailure n)  -> return n

Btw. you may want to enclose starting the process and closing the file
handles in a 'bracket'.