putChar package:haskeline

getInputChar :: (MonadIO m, MonadMask m) => String -> InputT m (Maybe Char)
haskeline System.Console.Haskeline
Reads one character of input. Ignores non-printable characters. When using terminal-style interaction, the character will be read without waiting for a newline. When using file-style interaction, a newline will be read if it is immediately available after the input character.