lock and unlock subcommands

Command/Lock.hs

@@ -0,0 +1,41 @@
+{- git-annex command
+ -
+ - Copyright 2010 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Command.Lock where
+
+import Control.Monad.State (liftIO)
+import System.Directory
+import System.Posix.Files
+
+import Command
+import Messages
+import qualified Annex
+import qualified GitRepo as Git
+
+{- Undo unlock -}
+start :: SubCmdStartString
+start file = do
+	-- Want to avoid calling git checkout on files that are not
+	-- annexed -- but without the symlink to the annex, cannot tell
+	-- for sure if the file was annexed. So, check if git thinks the
+	-- file's type has changed (from a symlink to a regular file).
+	g <- Annex.gitRepo
+	test <- liftIO $
+		Git.pipeRead g ["diff", "--name-only", "--diff-filter=T", file]
+	s <- liftIO $ getSymbolicLinkStatus file
+	if (null test || isSymbolicLink s)
+		then return Nothing
+		else do
+			showStart "lock" file
+			return $ Just $ perform file
+
+perform :: FilePath -> SubCmdPerform
+perform file = do
+	liftIO $ removeFile file
+	g <- Annex.gitRepo
+	liftIO $ Git.run g ["checkout", file]
+	return $ Just $ return True -- no cleanup needed