On Thu, Apr 14, 2011 at 8:50 AM, Daniel Fischer
$ cabal install stringsearch -- faster searches for a pattern than provided by bytestring
import qualified Data.ByteString.Char8 as BC import qualified Data.ByteString.Lazy as L import qualified Data.ByteString.Lazy.Search as L
blockSize = 512
main = do stuff <- L.readFile "blocks" case L.indices (BC.pack "PART") stuff of [] -> putStrLn "Not Found." (i:_) -> putStrLn $ "Found at " ++ show (i `quot` blockSize) ++ "." putStrLn "Done."
This solves a different problem. The original looked for PART only on the beginning of each block, while your solution will find everything that has PART in it. Because this is I/O bound, probably the real time taken won't be very different, but the program will surely use more CPU time and report more false positives. Cheers, -- Felipe.