Reading a password in Haskell

gistfile1.hs

import System.Posix.IO
import System.Posix.Terminal

readPassword :: IO String
readPassword = do
    echoOn <- getTerminalAttributes stdInput
    let echoOff = withoutMode echoOn EnableEcho
    fdWrite stdOutput "Password: "
    setTerminalAttributes stdInput echoOff Immediately
    pass <- getLine
    setTerminalAttributes stdInput echoOn Immediately
    fdWrite stdOutput "\n"
    return pass

main :: IO ()
main = readPassword >>= print