September Morn Update

Task/Keyboard-input-Flush-the-keyboard-buffer/Haskell/keyboard-input-flush-the-keyboard-buffer.hs

@@ -0,0 +1,26 @@
+import Control.Concurrent (threadDelay)
+import Control.Monad (when)
+import System.IO (hFlush, stdout)
+import System.Posix
+
+-- If the file descriptor is associated with a terminal, then flush its input,
+-- otherwise do nothing.
+termFlush :: Fd -> IO ()
+termFlush fd = do
+  isTerm <- queryTerminal fd
+  when isTerm $ discardData fd InputQueue
+
+main :: IO ()
+main = do
+  putStrLn "Type some stuff...\n"
+  threadDelay $ 3 * 1000000
+  putStrLn "\n\nOk, stop typing!\n"
+  threadDelay $ 2 * 1000000
+
+  termFlush stdInput
+
+  putStr "\n\nType a line of text, ending with a newline: "
+  hFlush stdout
+  line <- getLine
+  putStrLn $ "You typed: " ++ line
+  termFlush stdInput