argf.hs

import Data.ByteString (ByteString)
import System.Environment
import System.IO (openFile, IOMode (..))
import System.IO.Streams (InputStream, concatInputStreams, connectTo)
import System.IO.Streams.Handle (handleToInputStream, stdout)

argf :: IO (InputStream ByteString)
argf = do
  args <- fmap tail getArgs
  handles <- mapM (flip openFile ReadMode) args
  streams <- mapM handleToInputStream handles
  concatInputStreams streams

main :: IO ()
main = argf >>= connectTo stdout