Skip to content
Snippets Groups Projects

Getting stdout and stderr as a single handle from createProcess does not work on Windows

    • Closed Issue created by Simon Hengel @sol

    The following test case works on Linux (an as far as I know on Mac OS X too), but not on Windows.

    {-# OPTIONS_GHC -fno-warn-missing-signatures #-}
module Spec (main) where
import           Test.HUnit
import           System.Process
import           System.IO

subprocess = concat $
  [ "module Main where\n"
  , "import System.IO\n"
  , "main = do\n"
  , "  hPutStr stderr \"foo\"\n"
  , "  hFlush stderr\n"
  , "  hPutStrLn stdout \"bar\"\n"
  , "  hFlush stdout\n"
  ]

main = runTestTT $ TestCase $ do
  (Just hin, Just hout, Nothing, _) <-
    createProcess $ (proc "runhaskell" []) {
        std_in = CreatePipe
      , std_out = CreatePipe
      , std_err = UseHandle stdout
    }
  hPutStrLn hin subprocess
  hClose hin
  line <- hGetLine hout
  line @?= "foobar"

    Do we consider this a bug? If not, what would be the suggested way to do that?

    Trac metadata
    Trac field Value
    Version 7.2.1
    Type Bug
    TypeOfFailure OtherFailure
    Priority normal
    Resolution Unresolved
    Component libraries/process
    Test case
    Differential revisions
    BlockedBy
    Related
    Blocking
    CC
    Operating system
    Architecture
    To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information

    Child items 0

    • No child items are currently assigned. Use child items to break down this issue into smaller parts.

    Activity

    Please register or sign in to reply