libraries/base/tests/hGetBuf002.hs


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import System.IO
import Foreign
import Foreign.C

main = do test True; test False

test blocking = do
  h <- openBinaryFile "hGetBuf002.hs" ReadMode

  let sz = 42
      loop = do
         b <- allocaBytes sz $ \ptr -> do
                r <- (if blocking then hGetBuf else hGetBufNonBlocking) h ptr sz
                if (r == 0)
                   then return True
                   else do s <- peekCStringLen (ptr,r)
                           putStr s
                           return False
         if b then return () else loop -- tail call

  loop