Changes between Version 19 and Version 20 of HashSourceCodes

Timestamp:

Nov 21, 2009, 8:28:34 AM (14 years ago)

Author:

os

Comment:

--

HashSourceCodes

@@ -754 +754 @@
 
 }}}
+
+== Haskell ==
+{{{
+import IO(bracket)
+import System.Environment(getArgs)
+import System.IO(openBinaryFile,hClose,hFileSize,hSeek,IOMode(ReadMode),SeekMode(AbsoluteSeek,SeekFromEnd))
+import qualified Data.ByteString.Lazy as L(hGet,unpack)
+import Data.Binary.Get(runGet,getWord64le)
+import Data.Binary.Put(runPut,putWord64le)
+import Data.Word(Word64)
+import Control.Monad(foldM)
+import Data.Bits.Utils(w82s)
+import Data.Hex(hex)
+
+shortsum :: FilePath -> IO Word64
+shortsum filename = bracket (openBinaryFile filename ReadMode) hClose $ \h -> do
+  fs <- hFileSize h
+  hSeek h AbsoluteSeek 0 ; begin <- L.hGet h chunksize
+  hSeek h SeekFromEnd (-(toInteger chunksize)) ; end <- L.hGet h chunksize
+  return $ (flip runGet $ begin) $ chunksum $ (flip runGet $ end) (chunksum . fromInteger $ fs)
+  where
+    chunksize = 0x10000
+    chunksum n = foldM (\a _ -> getWord64le >>= return . (+a)) n [1..(chunksize`div`8)]
+
+main :: IO ()
+main = do
+  args <- getArgs
+  let fn = head $ args
+  p <- shortsum fn
+  putStrLn $ "The hash of file " ++ fn ++ ": " ++ (hex $ w82s $ reverse (L.unpack $ runPut $ putWord64le p))
+}}}