gistfile1.hs

import Data.Char
import Foreign.C.String
foreign import ccall "unistd.h crypt" c_crypt :: CString -> CString -> CString

trip ('#':str) = crypt str salt >>= return . ('◆':) . reverse . take 10 . reverse
    where
        substr x y = take y . drop x
        salt0 = substr 1 2 $ str ++ "H."
        salt1 = map (\x -> if ord x < ord '.' || ord x > ord 'z' then '.' else x) salt0
        table = zip ":;<=>?@[\\]^_`" "ABCDEFGabcdef"
        salt = map (\x -> maybe x id $ lookup x table) salt1
        crypt x y = do
            x' <- newCString x
            y' <- newCString y
            peekCString $ c_crypt x' y'

trip _ = error "えー"