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