Turn extensions lowercase

hashrename.hs

@@ -1,4 +1,5 @@
 import Control.Monad
+import Data.Char            (toLower)
 import Text.Printf          (printf)
 import Crypto.Hash.SHA1     (hash)
 import System.Environment   (getArgs)
@@ -22,7 +23,7 @@ newName path = do
   hash <- take 10 <$> fileHash path
   let (file, ext) = splitExtension path
       (dir, base) = splitFileName  file
-      new = dir </> hash <.> ext
+      new = dir </> hash <.> map toLower ext
   if null base
     then return path
     else return new