Hashell-0.15: Hashell/Signals.hs

{-
  Signals handlers routines.
  Copyright (C) 2005, 2008 Luis Francisco Araujo
-}

module Signals
    where

import System.IO (hPutStrLn, stderr)
import System.Exit -- (ExitFailure, exitFailure)
import Control.Exception -- (ExitException, handle)
import System.Posix.Signals -- (Handler(), installHandler, sigINT, Catch())

----------------------------------------------------------------------------------

{- | Set the signal-handler in the program.
   It is used for catching the SIGINT signal
   and preserves the shell running. -}
setSignalHandler :: IO Handler
setSignalHandler = installHandler sigINT (Catch signalHandler) Nothing

signalHandler :: IO ()
signalHandler = return $ throw (ExitException (ExitFailure 2))

handler :: IO a -> IO a
handler = handle (\e -> do hPutStrLn stderr (show e)
                           exitFailure)