drop: Add --batch and --json options.

CHANGELOG

@@ -3,7 +3,7 @@ git-annex (6.20160614) UNRELEASED; urgency=medium
   * Webapp: Don't allow deleting a remote that has syncing disabled,
     as such a deletion will never finish.
     Thanks, Farhan Kathawala.
-  * get: Add --batch and --json options.
+  * get, drop: Add --batch and --json options.
   * New url for git-remote-gcrypt, now maintained by spwhitton.
   * testremote: Fix crash when testing a freshly made external special remote.
 

Command/Drop.hs

@@ -23,7 +23,7 @@ import System.Log.Logger (debugM)
 import qualified Data.Set as S
 
 cmd :: Command
-cmd = withGlobalOptions (jobsOption : annexedMatchingOptions) $
+cmd = withGlobalOptions (jobsOption : jsonOption : annexedMatchingOptions) $
 	command "drop" SectionCommon
 		"remove content of files from repository"
 		paramPaths (seek <$$> optParser)
@@ -33,6 +33,7 @@ data DropOptions = DropOptions
 	, dropFrom :: Maybe (DeferredParse Remote)
 	, autoMode :: Bool
 	, keyOptions :: Maybe KeyOptions
+	, batchOption :: BatchMode
 	}
 
 optParser :: CmdParamsDesc -> Parser DropOptions
@@ -41,6 +42,7 @@ optParser desc = DropOptions
 	<*> optional parseDropFromOption
 	<*> parseAutoOption
 	<*> optional (parseKeyOptions False)
+	<*> parseBatchOption
 
 parseDropFromOption :: Parser (DeferredParse Remote)
 parseDropFromOption = parseRemoteOption $ strOption
@@ -51,10 +53,14 @@ parseDropFromOption = parseRemoteOption $ strOption
 
 seek :: DropOptions -> CommandSeek
 seek o = allowConcurrentOutput $
-	withKeyOptions (keyOptions o) (autoMode o)
+	case batchOption o of
+		Batch -> batchInput Right (batchCommandAction . go)
+		NoBatch -> withKeyOptions (keyOptions o) (autoMode o)
 			(startKeys o)
-		(withFilesInGit $ whenAnnexed $ start o)
+			(withFilesInGit go)
 			(dropFiles o)
+  where
+	go = whenAnnexed $ start o
 
 start :: DropOptions -> FilePath -> Key -> CommandStart
 start o file key = start' o key (Just file)

doc/git-annex-drop.mdwn

@@ -61,6 +61,16 @@ safe to do so.
   when git-annex has to contact remotes to check if it can drop files.
   For example: `-J4`  
 
+* `--batch`
+
+  Enables batch mode, in which lines containing names of files to drop
+  are read from stdin.
+
+* `--json`
+
+  Enable JSON output. This is intended to be parsed by programs that use
+  git-annex. Each line of output is a JSON object.
+
 # SEE ALSO
 
 [[git-annex]](1)

doc/todo/batch_get__47__drop__47__etc.mdwn

@@ -1,3 +1,6 @@
 in the spirit of [[todo/--batch_for_add/]], [[todo/--batch_for_info/]], [[todo/--batch_for_find/]] and [[todo/--batch_for_whereis/]], why not add `--batch` to get/drop/import operations?
 
 I am writing a script to get a bunch of arbitrary files and i want to avoid the overhead of running git-annex multiple times. I know i can use `annex.alwayscommit=false` but that is rather counter-intuitive as well. --[[anarcat]]
+
+> [[done]] for add and drop. (Not for import, but if someone requests it
+> with a use case we'll see.) --[[Joey]] 

doc/todo/drop_--batch.mdwn

@@ -1,3 +1,6 @@
 There is a dropkey --batch, so I guess I could workaround but probably would be nice for consistency to have --batch mode for drop itself as well
 
 [[!meta author=yoh]]
+
+> [[done]]; went ahead and added drop --batch to be symmetric with get
+> --batch. --[[Joey]]