contentlocation, examinekey, lookupkey: Added --batch mode option.

CmdLine/Batch.hs

@@ -0,0 +1,41 @@
+{- git-annex batch commands
+ -
+ - Copyright 2015 Joey Hess <id@joeyh.name>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module CmdLine.Batch where
+
+import Common.Annex
+import Command
+
+batchOption :: Option
+batchOption = flagOption [] "batch" "enable batch mode"
+
+data BatchMode = Batch | NoBatch
+type Batchable t = BatchMode -> t -> CommandStart
+
+-- A Batchable command can run in batch mode, or not.
+-- In batch mode, one line at a time is read, parsed, and a reply output to
+-- stdout. In non batch mode, the command's parameters are parsed and
+-- a reply output for each.
+batchable :: ((t -> CommandStart) -> CommandSeek) -> Batchable t -> CommandSeek
+batchable seeker starter params = ifM (getOptionFlag batchOption)
+	( batchloop
+	, seeker (starter NoBatch) params
+	)
+  where
+	batchloop = do
+		mp <- liftIO $ catchMaybeIO getLine
+		case mp of
+			Nothing -> return ()
+			Just p -> do
+				seeker (starter Batch) [p]
+				batchloop
+
+-- bad input is indicated by an empty line in batch mode. In non batch
+-- mode, exit on bad input.
+batchBadInput :: BatchMode -> Annex ()
+batchBadInput NoBatch = liftIO exitFailure
+batchBadInput Batch = liftIO $ putStrLn ""

Command/ContentLocation.hs

@@ -9,19 +9,20 @@ module Command.ContentLocation where
 
 import Common.Annex
 import Command
+import CmdLine.Batch
 import Annex.Content
 
 cmd :: [Command]
-cmd = [noCommit $ noMessages $
+cmd = [withOptions [batchOption] $ noCommit $ noMessages $
 	command "contentlocation" (paramRepeating paramKey) seek
 		SectionPlumbing "looks up content for a key"]
 
 seek :: CommandSeek
-seek = withKeys start
+seek = batchable withKeys start
 
-start :: Key -> CommandStart
+start :: Batchable Key
-start k = do
+start batchmode k = do
-	liftIO . maybe exitFailure putStrLn
+	maybe (batchBadInput batchmode) (liftIO . putStrLn)
 		=<< inAnnex' (pure True) Nothing check k
 	stop
   where

Command/ExamineKey.hs

@@ -9,21 +9,22 @@ module Command.ExamineKey where
 
 import Common.Annex
 import Command
+import CmdLine.Batch
 import qualified Utility.Format
 import Command.Find (formatOption, getFormat, showFormatted, keyVars)
 import Types.Key
 
 cmd :: [Command]
-cmd = [noCommit $ noMessages $ withOptions [formatOption, jsonOption] $
+cmd = [noCommit $ noMessages $ withOptions [formatOption, jsonOption, batchOption] $
 	command "examinekey" (paramRepeating paramKey) seek
 	SectionPlumbing "prints information from a key"]
 
 seek :: CommandSeek
 seek ps = do
 	format <- getFormat
-	withKeys (start format) ps
+	batchable withKeys (start format) ps
 
-start :: Maybe Utility.Format.Format -> Key -> CommandStart
+start :: Maybe Utility.Format.Format -> Batchable Key
-start format key = do
+start format _ key = do
 	showFormatted format (key2file key) (keyVars key)
 	stop

Command/LookupKey.hs

@@ -9,18 +9,20 @@ module Command.LookupKey where
 
 import Common.Annex
 import Command
+import CmdLine.Batch
 import Annex.CatFile
 import Types.Key
 
 cmd :: [Command]
-cmd = [notBareRepo $ noCommit $ noMessages $
+cmd = [withOptions [batchOption] $ notBareRepo $ noCommit $ noMessages $
 	command "lookupkey" (paramRepeating paramFile) seek
 		SectionPlumbing "looks up key used for file"]
 
 seek :: CommandSeek
-seek = withStrings start
+seek = batchable withStrings start
 
-start :: String -> CommandStart
+start :: Batchable String
-start file = do
+start batchmode file = do
-	liftIO . maybe exitFailure (putStrLn . key2file) =<< catKeyFile file
+	maybe (batchBadInput batchmode) (liftIO . putStrLn . key2file)
+		=<< catKeyFile file
 	stop

debian/changelog

@@ -30,6 +30,7 @@ git-annex (5.20150421) UNRELEASED; urgency=medium
   * Work around wget bug #784348 which could cause it to clobber git-annex
     symlinks when downloading from ftp.
   * Support checking ftp urls for file presence.
+  * contentlocation, examinekey, lookupkey: Added --batch mode option.
 
  -- Joey Hess <id@joeyh.name>  Tue, 21 Apr 2015 15:54:10 -0400
 

doc/git-annex-contentlocation.mdwn

@@ -16,6 +16,17 @@ Note that in direct mode, the file will typically be in the git work
 tree, and while its content should correspond to the key, the file
 could become modified at any time after git-annex checks it.
 
+# OPTIONS
+
+* `--batch`
+
+  Enable batch mode, in which a line containing the key is read from
+  stdin, the filename to its content is output to stdout (with a trailing
+  newline), and repeat.
+
+  Note that if a key's content is not present, an empty line is output to
+  stdout instead.
+
 # SEE ALSO
 
 [[git-annex]](1)

doc/git-annex-examinekey.mdwn

@@ -33,6 +33,11 @@ that can be determined purely by looking at the key.
   Enable JSON output. This is intended to be parsed by programs that use
   git-annex. Each line of output is a JSON object.
 
+* `--batch`
+
+  Enable batch mode, in which a line containing a key is read from stdin,
+  the information about it is output to stdout, and repeat.
+
 # EXAMPLES
 
 The location a key's value is stored (in indirect mode)

doc/git-annex-lookupkey.mdwn

@@ -13,6 +13,16 @@ index. The key is output to stdout. If there is no key (because
 the file is not present in the index, or is not a git-annex managed file),
 nothing is output, and it exits nonzero.
 
+# OPTIONS
+
+* `--batch`
+
+  Enable batch mode, in which a line containing the filename is read from
+  stdin, the key is output to stdout (with a trailing newline), and repeat.
+
+  Note that is there is no key corresponding to the file, an empty line is
+  output to stdout instead.
+
 # SEE ALSO
 
 [[git-annex]](1)