This commit is contained in:
Joey Hess 2012-02-20 15:20:36 -04:00
parent ac5cff3668
commit 6c0155efb7
4 changed files with 77 additions and 51 deletions

35
Utility/CoProcess.hs Normal file
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{- Interface for running a shell command as a coprocess,
- sending it queries and getting back results.
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Utility.CoProcess (
CoProcessHandle,
start,
stop,
query
) where
import System.Cmd.Utils
import Common
type CoProcessHandle = (PipeHandle, Handle, Handle)
start :: FilePath -> [String] -> IO CoProcessHandle
start command params = hPipeBoth command params
stop :: CoProcessHandle -> IO ()
stop (pid, from, to) = do
hClose to
hClose from
forceSuccess pid
query :: CoProcessHandle -> (Handle -> IO a) -> (Handle -> IO b) -> IO b
query (_, from, to) send receive = do
_ <- send to
hFlush to
receive from