git-annex/Git/Hook.hs
Joey Hess 4e35067325
windows hook scripts newlines without CR
Windows: When git-annex init is installing hook scripts, it will
avoid ending lines with CR for portability.

Existing hook scripts that do have CR line endings will not be changed.
While it would be possible to have git-annex init upgrade them, users would
need to know to use that command to do that, and it would add complexity
that does not seem warranted for the portability benefit alone.

Sponsored-by: Luke T. Shumaker on Patreon
2023-11-02 13:37:04 -04:00

115 lines
3.1 KiB
Haskell

{- git hooks
-
- Copyright 2013-2018 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
module Git.Hook where
import Common
import Git
import Utility.Tmp
import Utility.Shell
import Utility.FileMode
#ifndef mingw32_HOST_OS
import qualified Utility.RawFilePath as R
import System.PosixCompat.Files (fileMode)
#endif
import qualified Data.ByteString as B
data Hook = Hook
{ hookName :: FilePath
, hookScript :: String
, hookOldScripts :: [String]
}
deriving (Ord)
instance Eq Hook where
a == b = hookName a == hookName b
hookFile :: Hook -> Repo -> FilePath
hookFile h r = fromRawFilePath (localGitDir r) </> "hooks" </> hookName h
{- Writes a hook. Returns False if the hook already exists with a different
- content. Upgrades old scripts.
-
- This can install hooks on both filesystem like FAT that do not support
- execute bits, and on Windows.
-
- If the filesystem does not support execute bits, it's typically mounted
- such that all files have the execute bit set. So just write the hook
- and ignore failure to make it executable.
-
- On Windows, git will run hooks that are not executable. The hook
- is run with a bundled bash, so should start with #!/bin/sh
-}
hookWrite :: Hook -> Repo -> IO Bool
hookWrite h r = ifM (doesFileExist f)
( expectedContent h r >>= \case
UnexpectedContent -> return False
ExpectedContent -> return True
OldExpectedContent -> go
, go
)
where
f = hookFile h r
go = do
-- On Windows, using B.writeFile here avoids
-- the newline translation done by writeFile.
-- Hook scripts on Windows could use CRLF endings, but
-- they typically use unix newlines, which does work there
-- and makes the repository more portable.
viaTmp B.writeFile f (encodeBS (hookScript h))
void $ tryIO $ modifyFileMode
(toRawFilePath f)
(addModes executeModes)
return True
{- Removes a hook. Returns False if the hook contained something else, and
- could not be removed. -}
hookUnWrite :: Hook -> Repo -> IO Bool
hookUnWrite h r = ifM (doesFileExist f)
( expectedContent h r >>= \case
UnexpectedContent -> return False
_ -> do
removeFile f
return True
, return True
)
where
f = hookFile h r
data ExpectedContent = UnexpectedContent | ExpectedContent | OldExpectedContent
expectedContent :: Hook -> Repo -> IO ExpectedContent
expectedContent h r = do
-- Note that on windows, this readFile does newline translation,
-- and so a hook file that has CRLF will be treated the same as one
-- that has LF. That is intentional, since users may have a reason
-- to prefer one or the other.
content <- readFile $ hookFile h r
return $ if content == hookScript h
then ExpectedContent
else if any (content ==) (hookOldScripts h)
then OldExpectedContent
else UnexpectedContent
hookExists :: Hook -> Repo -> IO Bool
hookExists h r = do
let f = hookFile h r
catchBoolIO $
#ifndef mingw32_HOST_OS
isExecutable . fileMode <$> R.getFileStatus (toRawFilePath f)
#else
doesFileExist f
#endif
runHook :: Hook -> Repo -> IO Bool
runHook h r = do
let f = hookFile h r
(c, ps) <- findShellCommand f
boolSystem c ps