fromkey: Add stdin mode.

Command/FromKey.hs

@@ -5,6 +5,8 @@
  - Licensed under the GNU GPL version 3 or higher.
  -}
 
+{-# LANGUAGE BangPatterns #-}
+
 module Command.FromKey where
 
 import Common.Annex
@@ -33,16 +35,31 @@ start force (keyname:file:[]) = do
 			"key ("++ keyname ++") is not present in backend (use --force to override this sanity check)"
 	showStart "fromkey" file
 	next $ perform key file
+start _ [] = do
+	showStart "fromkey" "stdin"
+	next massAdd
 start _ _ = error "specify a key and a dest file"
 
+massAdd :: CommandPerform
+massAdd = go True =<< map words . lines <$> liftIO getContents
+  where
+	go status [] = next $ return status
+	go status ([keyname,f]:rest) = do
+		let key = fromMaybe (error $ "bad key " ++ keyname) $ file2key keyname
+		ok <- perform' key f
+		let !status' = status && ok
+		go status' rest
+	go status (_:rest) = error "Expected pairs of key and file on stdin, but got something else."
+
 perform :: Key -> FilePath -> CommandPerform
 perform key file = do
+	ok <- perform' key file
+	next $ return ok
+
+perform' :: Key -> FilePath -> Annex Bool
+perform' key file = do
 	link <- calcRepo $ gitAnnexLink file key
 	liftIO $ createDirectoryIfMissing True (parentDir file)
 	liftIO $ createSymbolicLink link file
-	next $ cleanup file
-
-cleanup :: FilePath -> CommandCleanup
-cleanup file = do
 	Annex.Queue.addCommand "add" [Param "--"] [file]
 	return True