directory-1.3.10.1: System/Directory/Internal/Common.hs
module System.Directory.Internal.Common
( module System.Directory.Internal.Common
, OsPath
, OsString
) where
import Prelude ()
import System.Directory.Internal.Prelude
import GHC.IO.Encoding.Failure (CodingFailureMode(TransliterateCodingFailure))
import GHC.IO.Encoding.UTF16 (mkUTF16le)
import GHC.IO.Encoding.UTF8 (mkUTF8)
import System.File.OsPath.Internal (openFileWithCloseOnExec)
import System.OsPath
( OsPath
, OsString
, addTrailingPathSeparator
, decodeUtf
, decodeWith
, encodeUtf
, hasTrailingPathSeparator
, isPathSeparator
, isRelative
, joinDrive
, joinPath
, normalise
, pack
, pathSeparator
, pathSeparators
, splitDirectories
, splitDrive
, toChar
, unpack
, unsafeFromChar
)
-- | A generator with side-effects.
newtype ListT m a = ListT { unListT :: m (Maybe (a, ListT m a)) }
emptyListT :: Applicative m => ListT m a
emptyListT = ListT (pure Nothing)
maybeToListT :: Applicative m => m (Maybe a) -> ListT m a
maybeToListT m = ListT (((\ x -> (x, emptyListT)) <$>) <$> m)
listToListT :: Applicative m => [a] -> ListT m a
listToListT [] = emptyListT
listToListT (x : xs) = ListT (pure (Just (x, listToListT xs)))
liftJoinListT :: Monad m => m (ListT m a) -> ListT m a
liftJoinListT m = ListT (m >>= unListT)
listTHead :: Functor m => ListT m a -> m (Maybe a)
listTHead (ListT m) = (fst <$>) <$> m
listTToList :: Monad m => ListT m a -> m [a]
listTToList (ListT m) = do
mx <- m
case mx of
Nothing -> return []
Just (x, m') -> do
xs <- listTToList m'
return (x : xs)
andM :: Monad m => m Bool -> m Bool -> m Bool
andM mx my = do
x <- mx
if x
then my
else return x
sequenceWithIOErrors_ :: [IO ()] -> IO ()
sequenceWithIOErrors_ actions = go (Right ()) actions
where
go :: Either IOError () -> [IO ()] -> IO ()
go (Left e) [] = ioError e
go (Right ()) [] = pure ()
go s (m : ms) = s `seq` do
r <- tryIOError m
go (s *> r) ms
-- | Similar to 'try' but only catches a specify kind of 'IOError' as
-- specified by the predicate.
tryIOErrorType :: (IOError -> Bool) -> IO a -> IO (Either IOError a)
tryIOErrorType check action = do
result <- tryIOError action
case result of
Left err -> if check err then pure (Left err) else throwIO err
Right val -> pure (Right val)
-- | Attempt to perform the given action, silencing any IO exception thrown by
-- it.
ignoreIOExceptions :: IO () -> IO ()
ignoreIOExceptions io = io `catchIOError` (\_ -> pure ())
specializeErrorString :: String -> (IOError -> Bool) -> IO a -> IO a
specializeErrorString str errType action = do
mx <- tryIOErrorType errType action
case mx of
Left e -> throwIO (ioeSetErrorString e str)
Right x -> pure x
ioeAddLocation :: IOError -> String -> IOError
ioeAddLocation e loc = do
ioeSetLocation e newLoc
where
newLoc = loc <> if null oldLoc then "" else ":" <> oldLoc
oldLoc = ioeGetLocation e
rightOrError :: Exception e => Either e a -> a
rightOrError (Left e) = error (displayException e)
rightOrError (Right a) = a
-- | Fallibly converts String to OsString. Only intended to be used on literals.
os :: String -> OsString
os = rightOrError . encodeUtf
-- | Fallibly converts OsString to String. Only intended to be used on literals.
so :: OsString -> String
so = rightOrError . decodeUtf
ioeSetOsPath :: IOError -> OsPath -> IOError
ioeSetOsPath err =
ioeSetFileName err .
rightOrError .
decodeWith
(mkUTF8 TransliterateCodingFailure)
(mkUTF16le TransliterateCodingFailure)
dropSpecialDotDirs :: [OsPath] -> [OsPath]
dropSpecialDotDirs = filter f
where f filename = filename /= os "." && filename /= os ".."
-- | Given a list of path segments, expand @.@ and @..@. The path segments
-- must not contain path separators.
expandDots :: [OsPath] -> [OsPath]
expandDots = reverse . go []
where
go ys' xs' =
case xs' of
[] -> ys'
x : xs
| x == os "." -> go ys' xs
| x == os ".." ->
case ys' of
[] -> go (x : ys') xs
y : ys
| y == os ".." -> go (x : ys') xs
| otherwise -> go ys xs
| otherwise -> go (x : ys') xs
-- | Convert to the right kind of slashes.
normalisePathSeps :: OsPath -> OsPath
normalisePathSeps p = pack (normaliseChar <$> unpack p)
where normaliseChar c = if isPathSeparator c then pathSeparator else c
-- | Remove redundant trailing slashes and pick the right kind of slash.
normaliseTrailingSep :: OsPath -> OsPath
normaliseTrailingSep path = do
let path' = reverse (unpack path)
let (sep, path'') = span isPathSeparator path'
let addSep = if null sep then id else (pathSeparator :)
pack (reverse (addSep path''))
-- | Convert empty paths to the current directory, otherwise leave it
-- unchanged.
emptyToCurDir :: OsPath -> OsPath
emptyToCurDir path
| path == mempty = os "."
| otherwise = path
-- | Similar to 'normalise' but empty paths stay empty.
simplifyPosix :: OsPath -> OsPath
simplifyPosix path
| path == mempty = mempty
| otherwise = normalise path
-- | Similar to 'normalise' but:
--
-- * empty paths stay empty,
-- * parent dirs (@..@) are expanded, and
-- * paths starting with @\\\\@ are preserved.
--
-- The goal is to preserve the meaning of paths better than 'normalise'.
simplifyWindows :: OsPath -> OsPath
simplifyWindows path
| path == mempty = mempty
| otherwise = case toChar <$> unpack drive' of
'\\' : '\\' : _ -> drive' <> subpath
_ -> simplifiedPath
where
simplifiedPath = joinDrive drive' subpath'
(drive, subpath) = splitDrive path
drive' = upperDrive (normaliseTrailingSep (normalisePathSeps drive))
subpath' = appendSep . avoidEmpty . prependSep . joinPath .
stripPardirs . expandDots . skipSeps .
splitDirectories $ subpath
upperDrive d = case unpack d of
c : k : s
| isAlpha (toChar c), toChar k == ':', all isPathSeparator s ->
-- unsafeFromChar is safe here since all characters are ASCII.
pack (unsafeFromChar (toUpper (toChar c)) : unsafeFromChar ':' : s)
_ -> d
skipSeps =
(pack <$>) .
filter (not . (`elem` (pure <$> pathSeparators))) .
(unpack <$>)
stripPardirs | pathIsAbsolute || subpathIsAbsolute = dropWhile (== os "..")
| otherwise = id
prependSep | subpathIsAbsolute = (pack [pathSeparator] <>)
| otherwise = id
avoidEmpty | not pathIsAbsolute
, drive == mempty || hasTrailingPathSep -- prefer "C:" over "C:."
= emptyToCurDir
| otherwise = id
appendSep p | hasTrailingPathSep, not (pathIsAbsolute && p == mempty)
= addTrailingPathSeparator p
| otherwise = p
pathIsAbsolute = not (isRelative path)
subpathIsAbsolute = any isPathSeparator (take 1 (unpack subpath))
hasTrailingPathSep = hasTrailingPathSeparator subpath
data WhetherFollow = NoFollow | FollowLinks deriving (Show)
isNoFollow :: WhetherFollow -> Bool
isNoFollow NoFollow = True
isNoFollow FollowLinks = False
data FileType = File
| SymbolicLink -- ^ POSIX: either file or directory link; Windows: file link
| Directory
| DirectoryLink -- ^ Windows only: directory link
deriving (Bounded, Enum, Eq, Ord, Read, Show)
-- | Check whether the given 'FileType' is considered a directory by the
-- operating system. This affects the choice of certain functions
-- e.g. 'System.Directory.removeDirectory' vs 'System.Directory.removeFile'.
fileTypeIsDirectory :: FileType -> Bool
fileTypeIsDirectory Directory = True
fileTypeIsDirectory DirectoryLink = True
fileTypeIsDirectory _ = False
-- | Return whether the given 'FileType' is a link.
fileTypeIsLink :: FileType -> Bool
fileTypeIsLink SymbolicLink = True
fileTypeIsLink DirectoryLink = True
fileTypeIsLink _ = False
data Permissions
= Permissions
{ readable :: Bool
, writable :: Bool
, executable :: Bool
, searchable :: Bool
} deriving (Eq, Ord, Read, Show)
withBinaryFile :: OsPath -> IOMode -> (Handle -> IO r) -> IO r
withBinaryFile path mode = bracket (openFileWithCloseOnExec path mode) hClose
-- | Copy data from one handle to another until end of file.
copyHandleData :: Handle -- ^ Source handle
-> Handle -- ^ Destination handle
-> IO ()
copyHandleData hFrom hTo =
(`ioeAddLocation` "copyData") `modifyIOError` do
allocaBytes bufferSize go
where
bufferSize = 131072 -- 128 KiB, as coreutils `cp` uses as of May 2014 (see ioblksize.h)
go buffer = do
count <- hGetBuf hFrom buffer bufferSize
when (count > 0) $ do
hPutBuf hTo buffer count
go buffer
-- | Special directories for storing user-specific application data,
-- configuration, and cache files, as specified by the
-- <http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html XDG Base Directory Specification>.
--
-- Note: On Windows, 'XdgData' and 'XdgConfig' usually map to the same
-- directory.
--
-- @since 1.2.3.0
data XdgDirectory
= XdgData
-- ^ For data files (e.g. images).
-- It uses the @XDG_DATA_HOME@ environment variable.
-- On non-Windows systems, the default is @~\/.local\/share@.
-- On Windows, the default is @%APPDATA%@
-- (e.g. @C:\/Users\//\<user\>/\/AppData\/Roaming@).
-- Can be considered as the user-specific equivalent of @\/usr\/share@.
| XdgConfig
-- ^ For configuration files.
-- It uses the @XDG_CONFIG_HOME@ environment variable.
-- On non-Windows systems, the default is @~\/.config@.
-- On Windows, the default is @%APPDATA%@
-- (e.g. @C:\/Users\//\<user\>/\/AppData\/Roaming@).
-- Can be considered as the user-specific equivalent of @\/etc@.
| XdgCache
-- ^ For non-essential files (e.g. cache).
-- It uses the @XDG_CACHE_HOME@ environment variable.
-- On non-Windows systems, the default is @~\/.cache@.
-- On Windows, the default is @%LOCALAPPDATA%@
-- (e.g. @C:\/Users\//\<user\>/\/AppData\/Local@).
-- Can be considered as the user-specific equivalent of @\/var\/cache@.
| XdgState
-- ^ For data that should persist between (application) restarts,
-- but that is not important or portable enough to the user that it
-- should be stored in 'XdgData'.
-- It uses the @XDG_STATE_HOME@ environment variable.
-- On non-Windows sytems, the default is @~\/.local\/state@. On
-- Windows, the default is @%LOCALAPPDATA%@
-- (e.g. @C:\/Users\//\<user\>/\/AppData\/Local@).
--
-- @since 1.3.7.0
deriving (Bounded, Enum, Eq, Ord, Read, Show)
-- | Search paths for various application data, as specified by the
-- <http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html XDG Base Directory Specification>.
--
-- The list of paths is split using 'System.FilePath.searchPathSeparator',
-- which on Windows is a semicolon.
--
-- Note: On Windows, 'XdgDataDirs' and 'XdgConfigDirs' usually yield the same
-- result.
--
-- @since 1.3.2.0
data XdgDirectoryList
= XdgDataDirs
-- ^ For data files (e.g. images).
-- It uses the @XDG_DATA_DIRS@ environment variable.
-- On non-Windows systems, the default is @\/usr\/local\/share\/@ and
-- @\/usr\/share\/@.
-- On Windows, the default is @%PROGRAMDATA%@ or @%ALLUSERSPROFILE%@
-- (e.g. @C:\/ProgramData@).
| XdgConfigDirs
-- ^ For configuration files.
-- It uses the @XDG_CONFIG_DIRS@ environment variable.
-- On non-Windows systems, the default is @\/etc\/xdg@.
-- On Windows, the default is @%PROGRAMDATA%@ or @%ALLUSERSPROFILE%@
-- (e.g. @C:\/ProgramData@).
deriving (Bounded, Enum, Eq, Ord, Read, Show)