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-- !!! Flushing
module Main(main) where
import Control.Monad
import System.Directory ( removeFile, doesFileExist )
import System.IO
import System.IO.Error
main = do
hFlush stdin `catchIOError` \ _ -> putStrLn "No can do - flushing read-only handles isn't legal"
putStr "Hello,"
hFlush stdout
putStr "Hello - "
hFlush stderr
hdl <- openFile "hFlush001.hs" ReadMode
hFlush hdl `catchIOError` \ _ -> putStrLn "No can do - flushing read-only handles isn't legal"
hClose hdl
remove
hdl <- openFile "hFlush001.out" WriteMode
hFlush hdl
hClose hdl
remove
hdl <- openFile "hFlush001.out" AppendMode
hFlush hdl
hClose hdl
remove
hdl <- openFile "hFlush001.out" ReadWriteMode
hFlush hdl
hClose hdl
where remove = do
f <- doesFileExist "hFlush001.out"
when f (removeFile "hFlush001.out")
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