Re: [Haskell-cafe] How to terminate the process group of a processcreated with createProcess?

12 Jan 2012

      On 11.01.2012 at 23:08 Donn Cave wrote:
...
Quoth Brandon Allbery ,
...
...
terminateProcess passes on the semantics of kill(2); on SVID-compliant
(and I think POSIX.1-compliant) systems, the negative of the process
group leader's process ID is used to signal the process group.  Note
that you may need to arrange for your initial child process to invoke
setpgrp() to insure that the parent program is not part of the process
group.
... and that stuff can be found in System.Posix.Process.  Support for
POSIX killpg can be found in System.Posix.Signals, by the way in case
you think that would make your intention more transparent.
I tried:

import System.Posix.Process
import System.Posix.Signals
import System.Process
import System.Process.Internals

terminateProcessGroup :: ProcessHandle -> IO ()
terminateProcessGroup ph = do
    let (ProcessHandle pmvar) = ph
    ph_ <- readMVar pmvar
    case ph_ of
        OpenHandle pid -> do  -- pid is a POSIX pid
            gid <- createProcessGroup pid
            signalProcessGroup 15 pid
        otherwise -> error "Somethings wrong."

but i get the error message:
"createProcessGroup: permission denied"

Is there a way around this permission problem?

Kind regards, 
André

Re: [Haskell-cafe] How to terminate the process group of a processcreated with createProcess?

André Scholz