git-annex/Utility/Directory/Create.hs
2020-11-02 15:36:11 -04:00

102 lines
3.4 KiB
Haskell

{- directory creating
-
- Copyright 2011-2020 Joey Hess <id@joeyh.name>
-
- License: BSD-2-clause
-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE LambdaCase #-}
{-# OPTIONS_GHC -fno-warn-tabs #-}
module Utility.Directory.Create (
createDirectoryUnder,
createDirectoryUnder',
) where
import Control.Monad
import Control.Applicative
import Control.Monad.IO.Class
import Control.Monad.IfElse
import System.IO.Error
import Data.Maybe
import qualified System.FilePath.ByteString as P
import Prelude
import Utility.SystemDirectory
import Utility.Path.AbsRel
import Utility.Exception
import Utility.FileSystemEncoding
import qualified Utility.RawFilePath as R
import Utility.PartialPrelude
{- Like createDirectoryIfMissing True, but it will only create
- missing parent directories up to but not including the directory
- in the first parameter.
-
- For example, createDirectoryUnder "/tmp/foo" "/tmp/foo/bar/baz"
- will create /tmp/foo/bar if necessary, but if /tmp/foo does not exist,
- it will throw an exception.
-
- The exception thrown is the same that createDirectory throws if the
- parent directory does not exist.
-
- If the second FilePath is not under the first
- FilePath (or the same as it), it will fail with an exception
- even if the second FilePath's parent directory already exists.
-
- Either or both of the FilePaths can be relative, or absolute.
- They will be normalized as necessary.
-
- Note that, the second FilePath, if relative, is relative to the current
- working directory, not to the first FilePath.
-}
createDirectoryUnder :: RawFilePath -> RawFilePath -> IO ()
createDirectoryUnder topdir dir =
createDirectoryUnder' topdir dir R.createDirectory
createDirectoryUnder'
:: (MonadIO m, MonadCatch m)
=> RawFilePath
-> RawFilePath
-> (RawFilePath -> m ())
-> m ()
createDirectoryUnder' topdir dir0 mkdir = do
p <- liftIO $ relPathDirToFile topdir dir0
let dirs = P.splitDirectories p
-- Catch cases where the dir is not beneath the topdir.
-- If the relative path between them starts with "..",
-- it's not. And on Windows, if they are on different drives,
-- the path will not be relative.
if headMaybe dirs == Just ".." || P.isAbsolute p
then liftIO $ ioError $ customerror userErrorType
("createDirectoryFrom: not located in " ++ fromRawFilePath topdir)
-- If dir0 is the same as the topdir, don't try to create
-- it, but make sure it does exist.
else if null dirs
then liftIO $ unlessM (doesDirectoryExist (fromRawFilePath topdir)) $
ioError $ customerror doesNotExistErrorType
"createDirectoryFrom: does not exist"
else createdirs $
map (topdir P.</>) (reverse (scanl1 (P.</>) dirs))
where
customerror t s = mkIOError t s Nothing (Just (fromRawFilePath dir0))
createdirs [] = pure ()
createdirs (dir:[]) = createdir dir (liftIO . ioError)
createdirs (dir:dirs) = createdir dir $ \_ -> do
createdirs dirs
createdir dir (liftIO . ioError)
-- This is the same method used by createDirectoryIfMissing,
-- in particular the handling of errors that occur when the
-- directory already exists. See its source for explanation
-- of several subtleties.
createdir dir notexisthandler = tryIO (mkdir dir) >>= \case
Right () -> pure ()
Left e
| isDoesNotExistError e -> notexisthandler e
| isAlreadyExistsError e || isPermissionError e ->
liftIO $ unlessM (doesDirectoryExist (fromRawFilePath dir)) $
ioError e
| otherwise -> liftIO $ ioError e