readpresentkey: New plumbing command for checking location log.

Command/ReadPresentKey.hs

@@ -0,0 +1,30 @@
+{- git-annex command
+ -
+ - Copyright 2015 Joey Hess <id@joeyh.name>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Command.ReadPresentKey where
+
+import Common.Annex
+import Command
+import Logs.Location
+import Types.Key
+
+cmd :: [Command]
+cmd = [noCommit $ command "readpresentkey" (paramPair paramKey paramUUID) seek
+	SectionPlumbing "read records of where key is present"] 
+
+seek :: CommandSeek
+seek = withWords start
+
+start :: [String] -> CommandStart
+start (ks:us:[]) = do
+	ls <- loggedLocations k
+	if toUUID us `elem` ls
+		then liftIO exitSuccess
+		else liftIO exitFailure
+  where
+	k = fromMaybe (error "bad key") (file2key ks)
+start _ = error "Wrong number of parameters"