[Haskell] Re: Capturing output from System.system

[Ferenc Wagner]

"David House" <dmhouse at gmail.com> writes:

> Sorry Mads for multiple copies.
>
> On 16/01/07, Mads Lindstrøm <mads_lindstroem at yahoo.dk> wrote:
>
>> The function System.system (:: String -> IO ExitCode) makes the OS
>> execute it first parameter as a command. It prints its output to
>> standard output and standard error.
>>
>> How do I easily capture this output?
>
> Try System.Process.runInteractiveCommand:
>
> import System.Process
> import System.IO
>
> main = do
>   (inH, outH, errH, _) <- runInteractiveCommand "wc -w"
>   hPutStr inH "foo bar baz"
>   ws <- hGetContents outH
>   putStrLn ws
>
> -- Prints 3

Beware, deadlocks ahead.  See:

http://www.haskell.org/pipermail/libraries/2006-December/006635.html
http://www.haskell.org/pipermail/haskell-cafe/2006-December/020528.html
-- 
Feri.