{-# LANGUAGE Arrows #-}
module JuicyBar.Input.Command (getCommandOutput) where
import FRP.Grapefruit.Signal as Signal
import FRP.Grapefruit.Signal.Continuous as CSignal
import FRP.Grapefruit.Circuit as Circuit
import Control.Arrow as Arrow
import System.IO
import System.Process

produceCommandOutput :: String -> IO String
produceCommandOutput cmd = do
  (_,out,_,_) <- runInteractiveCommand cmd
  l <- hGetLine out `catch` const (return $ "Error while running '"++cmd++"'")
  hClose out
  return l

getCommandOutput :: Circuit era String (CSignal era String)
getCommandOutput = proc cmd -> produce $ CSignal.producer $ produceCommandOutput cmd -<< ()