RE: POpen, opening lots of processes
> > There is an outstanding proposal for a System.Process library: > > > > http://www.haskell.org/~simonmar/System.Process.html > > > > This is currently stalled because we need a non-blocking > > implementation of getProcessStatus (which is in the > > pipeline). Something akin to Tomasz's launch could also > > be included here. > > How is it different from System.Posix.Process? Supposed to > be more portable? Sounds good. Yes, it is a portable process library. Cheers, Simon ___ Glasgow-haskell-users mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: POpen, opening lots of processes
"Simon Marlow" <[EMAIL PROTECTED]> writes: >> Tomasz Zielonka <[EMAIL PROTECTED]> writes: >> >>> I had a similar problem, and finally I created my own >>> solution that doesn't leave zombies and doesn't block when >>> the launched process writes too much to stderr. >> >> Pretty neat, I've got an application idea for that code! >> Couldn't it be include in the standard libraries? Anyway, >> thanks for posting it. > > There is an outstanding proposal for a System.Process library: > > http://www.haskell.org/~simonmar/System.Process.html > > This is currently stalled because we need a non-blocking > implementation of getProcessStatus (which is in the > pipeline). Something akin to Tomasz's launch could also > be included here. How is it different from System.Posix.Process? Supposed to be more portable? Sounds good. Feri. ___ Glasgow-haskell-users mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
RE: POpen, opening lots of processes
> Tomasz Zielonka <[EMAIL PROTECTED]> writes: > > > I had a similar problem, and finally I created my own > > solution that doesn't leave zombies and doesn't block when > > the launched process writes too much to stderr. > > Pretty neat, I've got an application idea for that code! > Couldn't it be include in the standard libraries? Anyway, > thanks for posting it. There is an outstanding proposal for a System.Process library: http://www.haskell.org/~simonmar/System.Process.html This is currently stalled because we need a non-blocking implementation of getProcessStatus (which is in the pipeline). Something akin to Tomasz's launch could also be included here. Cheers, Simon ___ Glasgow-haskell-users mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: POpen, opening lots of processes
Tomasz Zielonka <[EMAIL PROTECTED]> writes: > I had a similar problem, and finally I created my own > solution that doesn't leave zombies and doesn't block when > the launched process writes too much to stderr. Pretty neat, I've got an application idea for that code! Couldn't it be include in the standard libraries? Anyway, thanks for posting it. Feri. ___ Glasgow-haskell-users mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: POpen, opening lots of processes
On Thu, Jan 08, 2004 at 09:33:29AM -0800, Hal Daume III wrote: > Hi, > > I'm using POpen to shell out to a command several hundreds or thousands of > times per call (none of them simultaneous, though, this is completely > serial). After running my program for a while, I get: > > Fail: resource exhausted > Action: forkProcess > Reason: Resource temporarily unavailable > > which basically seems to be telling me that the program hasn't been > closing the old processes, even though they're definitely not in use > anymore. > > Does anyone have any suggestions how to get around this? I had a similar problem, and finally I created my own solution that doesn't leave zombies and doesn't block when the launched process writes too much to stderr. I tested it in GHC 6.0. For 6.2 you'd have to change the use of forkProcess. Usage: launch :: String -> [String] -> String -> IO (ProcessStatus, String, String) (status, out, err) <- launch prog args progInput Example: *Shell> (status, out, err) <- launch "tr" ["a-z", "A-Z"] (unlines (replicate 1 "Haskell")) *Shell> status Exited ExitSuccess *Shell> length out 8 *Shell> mapM_ putStrLn (take 10 (lines out)) HASKELL HASKELL HASKELL HASKELL HASKELL HASKELL HASKELL HASKELL HASKELL HASKELL Best regards, Tom -- .signature: Too many levels of symbolic links module Shell where import System.Posix.Process import System.Posix.IO import Control.Concurrent import IO launch :: String -> [String] -> String -> IO (ProcessStatus, String, String) launch prog args inputStr = do (childIn, parentIn) <- createPipe (parentOut, childOut) <- createPipe (parentErr, childErr) <- createPipe forkProcess >>= \pid -> case pid of Nothing -> do -- child closeFd parentIn closeFd parentOut closeFd parentErr closeFd 0 -- FIXME: What if some of 0,1,2 are already closed? closeFd 1 closeFd 2 childIn `dupTo` 0 childOut `dupTo` 1 childErr `dupTo` 2 closeFd childIn closeFd childOut closeFd childErr executeFile prog True args Nothing fail "launch: executeFile failed" Just child -> do -- parent closeFd childIn closeFd childOut closeFd childErr input <- fdToHandle parentIn output <- fdToHandle parentOut err <- fdToHandle parentErr outputCS <- hGetContents output errCS <- hGetContents err outputMV <- newEmptyMVar errMV <- newEmptyMVar inputMV <- newEmptyMVar forkIO $ hPutStr input inputStr >> hClose input >> putMVar inputMV () forkIO $ foldr seq () outputCS `seq` hClose output >> putMVar outputMV () forkIO $ foldr seq () errCS `seq` hClose err >> putMVar errMV () takeMVar outputMV takeMVar errMV takeMVar inputMV mStatus <- getProcessStatus True False child case mStatus of Nothing -> fail "launch: can't get child process status" Just stat -> return (stat, outputCS, errCS) ___ Glasgow-haskell-users mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
