hexdump in Haskell

hexdump.hs

import Data.Char
import System.IO
import Text.Printf

main = do
  hSetBinaryMode stdin True
  contents <- getContents
  putStr (hexdump contents)

hexdump :: String -> String
hexdump contents = 
    let chunks = chunkify 8 contents
        hexchunks = map hexify chunks
        pchunks = map (\chunk -> map (\c -> if (isAscii c && c /= '\n') then c else '.') chunk) chunks
        dump = map (\(h, p) -> printf "%-24s %s" h p) (zip hexchunks pchunks)
    in  unlines dump

chunkify :: Int -> [a] -> [[a]]
chunkify _ [] = []
chunkify chunksize l = chunk : chunkify chunksize rest
    where (chunk, rest) = splitAt chunksize l

hexify :: String -> String
hexify = unwords . map (printf "%02x" . ord :: Char -> String)