git-annex/Command/CheckPresentKey.hs
Joey Hess 1d1054faa6
added -z
Added -z option to git-annex commands that use --batch, useful for
supporting filenames containing newlines.

It only controls input to --batch, the output will still be line delimited
unless --json or etc is used to get some other output. While git often
makes -z affect both input and output, I don't like trying them together,
and making it affect output would have been a significant complication,
and also git-annex output is generally not intended to be machine parsed,
unless using --json or a format option.

Commands that take pairs like "file key" still separate them with a space
in --batch mode. All such commands take care to support filenames with
spaces when parsing that, so there was no need to change it, and it would
have needed significant changes to the batch machinery to separate tose
with a null.

To make fromkey and registerurl support -z, I had to give them a --batch
option. The implicit batch mode they enter when not provided with input
parameters does not support -z as that would have complicated option
parsing. Seemed better to move these toward using the same --batch as
everything else, though the implicit batch mode can still be used.

This commit was sponsored by Ole-Morten Duesund on Patreon.
2018-09-20 16:11:47 -04:00

76 lines
2.1 KiB
Haskell

{- git-annex command
-
- Copyright 2015-2016 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Command.CheckPresentKey where
import Command
import qualified Remote
cmd :: Command
cmd = noCommit $ noMessages $
command "checkpresentkey" SectionPlumbing
"check if key is present in remote"
(paramPair paramKey (paramOptional paramRemote))
(seek <$$> optParser)
data CheckPresentKeyOptions = CheckPresentKeyOptions
{ params :: CmdParams
, batchOption :: BatchMode
}
optParser :: CmdParamsDesc -> Parser CheckPresentKeyOptions
optParser desc = CheckPresentKeyOptions
<$> cmdParams desc
<*> parseBatchOption
seek :: CheckPresentKeyOptions -> CommandSeek
seek o = case batchOption o of
NoBatch -> case params o of
(ks:rn:[]) -> toRemote rn >>= (check ks . Just) >>= exitResult
(ks:[]) -> check ks Nothing >>= exitResult
_ -> wrongnumparams
Batch fmt -> do
checker <- case params o of
(rn:[]) -> toRemote rn >>= \r -> return (flip check (Just r))
[] -> return (flip check Nothing)
_ -> wrongnumparams
batchInput fmt Right $ checker >=> batchResult
where
wrongnumparams = giveup "Wrong number of parameters"
data Result = Present | NotPresent | CheckFailure String
check :: String -> Maybe Remote -> Annex Result
check ks mr = case mr of
Nothing -> go Nothing =<< Remote.keyPossibilities k
Just r -> go Nothing [r]
where
k = toKey ks
go Nothing [] = return NotPresent
go (Just e) [] = return $ CheckFailure e
go olderr (r:rs) = Remote.hasKey r k >>= \case
Right True -> return Present
Right False -> go olderr rs
Left e -> go (Just e) rs
exitResult :: Result -> Annex a
exitResult Present = liftIO exitSuccess
exitResult NotPresent = liftIO exitFailure
exitResult (CheckFailure msg) = liftIO $ do
hPutStrLn stderr msg
exitWith $ ExitFailure 100
batchResult :: Result -> Annex ()
batchResult Present = liftIO $ putStrLn "1"
batchResult _ = liftIO $ putStrLn "0"
toKey :: String -> Key
toKey = fromMaybe (giveup "Bad key") . file2key
toRemote :: String -> Annex Remote
toRemote rn = maybe (giveup "Unknown remote") return
=<< Remote.byNameWithUUID (Just rn)