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{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE MultiWayIf #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards #-}
module Flameshot.Internal.Process (run,Callbacks(..),writeDaemon) where
import Control.Concurrent (forkIO,threadDelay)
import Control.Concurrent.Async (race)
import Control.Exception
import Control.Monad.Extended (untilM_,unless,void)
import Data.ByteString (ByteString)
import qualified Data.ByteString as BS
import Data.Text (Text)
import qualified Data.Text.IO as T
import System.Exit
import System.IO (BufferMode(LineBuffering),hSetBuffering)
import System.IO (Handle,hClose,hPutStr,hIsEOF)
import System.IO.Error (catchIOError,isDoesNotExistError)
import System.Process
import System.Posix.Directory (changeWorkingDirectory)
import System.Posix.Files (setFileCreationMask)
import System.Posix.IO (closeFd,dupTo,openFd,stdError,stdInput,stdOutput)
import System.Posix.IO (defaultFileFlags,OpenMode(WriteOnly))
import System.Posix.Process (createSession,forkProcess,getProcessStatus)
import System.Posix.Process (getProcessGroupIDOf)
import System.Posix.Signals (Signal,signalProcessGroup,killProcess)
import System.Posix.Types (ProcessGroupID)
data Callbacks = Callbacks
{ onOutLine :: Pid -> Text -> IO ()
, onErrLine :: Pid -> Text -> IO ()
, onError :: Pid -> SomeException -> IO ()
, onExit :: Pid -> ExitCode -> IO ()
, onStart :: Pid -> IO ()
}
run :: FilePath
-> [String]
-> Maybe FilePath
-> Maybe [(String, String)]
-> String
-> Maybe Int
-> Callbacks
-> IO ()
run path args cwd env input hTimeout Callbacks{..} =
f `catch` onError (-1)
where
f = withCreateProcess p $ \(Just inh) (Just outh) (Just errh) ph -> do
Just pid <- getPid ph
pgid <- getProcessGroupIDOf pid
onStart pid
mapM_ forkIO [
hPutStr inh input `finally` hClose inh,
hWithLines outh (onOutLine pid),
hWithLines errh (onErrLine pid)
]
case hTimeout of
Just time ->
race (threadDelay time) (waitForProcess ph) >>= \case
Left () -> onError pid (SomeException (ErrorCall "timeout"))
Right code -> onExit pid code
Nothing ->
waitForProcess ph >>= onExit pid
killProcessGroup pgid
p = (proc path args)
{ cwd = cwd
, env = env
, std_in = CreatePipe
, std_out = CreatePipe
, std_err = CreatePipe
, close_fds = True
, create_group = True
, new_session = True
}
writeDaemon :: FilePath -> [String] -> ByteString -> IO ()
writeDaemon path args input = do
pid <- forkProcess $ do
_ <- setFileCreationMask 0o0027
_ <- createSession
changeWorkingDirectory "/"
closeFd stdInput
bracket (openFd "/dev/null" WriteOnly Nothing defaultFileFlags) closeFd
$ \hnull -> mapM_ (dupTo hnull) [stdOutput, stdError]
(Just hin, _, _, _) <-
createProcess (proc path args) { std_in = CreatePipe }
BS.hPut hin input
hClose hin
void (getProcessStatus True False pid)
killProcessGroup :: ProcessGroupID -> IO ()
killProcessGroup = signalProcessGroup' killProcess
signalProcessGroup' :: Signal -> ProcessGroupID -> IO ()
signalProcessGroup' sig pgid =
catchIOError
(signalProcessGroup sig pgid)
(\e -> unless (isDoesNotExistError e) $ ioError e)
hWithLines :: Handle -> (Text -> IO ()) -> IO ()
hWithLines h f = do
hSetBuffering h LineBuffering
untilM_ (hIsEOF h) (T.hGetLine h >>= f) `finally` hClose h
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