[Haskell-beginners] Invoke an external command

Hi, I am trying to pass on arguments and standard input to an external command, and get back its standard output real time. I used "readProcess" from "System.Process" module. It is working fine except that the output is returned strictly, i.e., the output was dumped to the screen all at once when the command was finished. I also tried HSH module and it acted the same as readProcess: runIO $ setenv [("TERM", standard_input)] $ "echo $TERM" -|- (command ++ " " ++ (intercalate " " argsListOfStrings)). Can anyone help me? Thanks, Hong