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------------------------------------------------------------------------------ --- This library is a direct port of the Haskell library System.FilePath --- of Neil Mitchell. --- --- @author Bjoern Peemoeller --- @version November 2011 --- @category general ------------------------------------------------------------------------------ -- -- Some short examples: -- -- You are given a C file, you want to figure out the corresponding object (.o) file: -- -- @'replaceExtension' file \"o\"@ -- -- Haskell module Main imports Test, you have the file named main: -- -- @['replaceFileName' path_to_main \"Test\" '<.>' ext | ext <- [\"hs\",\"lhs\"] ]@ -- -- You want to download a file from the web and save it to disk: -- -- @do let file = 'makeValid' url -- System.IO.createDirectoryIfMissing True ('takeDirectory' file)@ -- -- You want to compile a Haskell file, but put the hi file under \"interface\" -- -- @'takeDirectory' file '</>' \"interface\" '</>' ('takeFileName' file \`replaceExtension\` \"hi\"@) -- -- The examples in code format descibed by each function are used to generate -- tests, and should give clear semantics for the functions. ----------------------------------------------------------------------------- module FilePath ( -- * Separator predicates FilePath, pathSeparator, pathSeparators, isPathSeparator, searchPathSeparator, isSearchPathSeparator, extSeparator, isExtSeparator, -- * Path methods (environment $PATH) splitSearchPath, getSearchPath, -- * Extension methods splitExtension, takeExtension, replaceExtension, dropExtension, addExtension, hasExtension, (<.>), splitExtensions, dropExtensions, takeExtensions, isExtensionOf, -- * Drive methods splitDrive, joinDrive, takeDrive, hasDrive, dropDrive, isDrive, -- * Operations on a FilePath, as a list of directories splitFileName, takeFileName, replaceFileName, dropFileName, takeBaseName, replaceBaseName, takeDirectory, replaceDirectory, combine, (</>), splitPath, joinPath, splitDirectories, -- * Low level FilePath operators hasTrailingPathSeparator, addTrailingPathSeparator, dropTrailingPathSeparator, -- * File name manipulators normalise, equalFilePath, makeRelative, isRelative, isAbsolute, isValid, makeValid ) where import Char (toLower, toUpper) import List (isPrefixOf, isSuffixOf, init, last) import Maybe (isJust, fromJust) import System (getEnviron, isPosix, isWindows) infixr 7 <.> infixr 5 </> type FilePath = String --------------------------------------------------------------------- -- The basic functions -- | The character that separates directories. In the case where more than -- one character is possible, 'pathSeparator' is the \'ideal\' one. -- -- > Windows: pathSeparator == '\\' -- > Posix: pathSeparator == '/' -- > isPathSeparator pathSeparator pathSeparator :: Char pathSeparator = if isWindows then '\\' else '/' -- | The list of all possible separators. -- -- > Windows: pathSeparators == ['\\', '/'] -- > Posix: pathSeparators == ['/'] -- > pathSeparator `elem` pathSeparators pathSeparators :: [Char] pathSeparators = if isWindows then "\\/" else "/" -- | Rather than using @(== 'pathSeparator')@, use this. Test if something -- is a path separator. -- -- > isPathSeparator a == (a `elem` pathSeparators) isPathSeparator :: Char -> Bool isPathSeparator = (`elem` pathSeparators) -- | The character that is used to separate the entries in the $PATH -- environment variable. -- -- > Windows: searchPathSeparator == ';' -- > Posix: searchPathSeparator == ':' searchPathSeparator :: Char searchPathSeparator = if isWindows then ';' else ':' -- | Is the character a file separator? -- -- > isSearchPathSeparator a == (a == searchPathSeparator) isSearchPathSeparator :: Char -> Bool isSearchPathSeparator = (== searchPathSeparator) -- | File extension character -- -- > extSeparator == '.' extSeparator :: Char extSeparator = '.' -- | Is the character an extension character? -- -- > isExtSeparator a == (a == extSeparator) isExtSeparator :: Char -> Bool isExtSeparator = (== extSeparator) --------------------------------------------------------------------- -- Path methods (environment $PATH) -- | Take a string, split it on the 'searchPathSeparator' character. -- -- Follows the recommendations in -- <http://www.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap08.html> -- -- > Posix: splitSearchPath "File1:File2:File3" == ["File1","File2","File3"] -- > Posix: splitSearchPath "File1::File2:File3" == ["File1",".","File2","File3"] -- > Windows: splitSearchPath "File1;File2;File3" == ["File1","File2","File3"] -- > Windows: splitSearchPath "File1;;File2;File3" == ["File1","File2","File3"] splitSearchPath :: String -> [FilePath] splitSearchPath = f where f xs = case break isSearchPathSeparator xs of (pre, [] ) -> g pre (pre, _:post) -> g pre ++ f post g [] = ["." | isPosix] g x@(_:_) = [x] -- | Get a list of filepaths in the $PATH. getSearchPath :: IO [FilePath] getSearchPath = getEnviron "PATH" >>= return . splitSearchPath --------------------------------------------------------------------- -- Extension methods -- | Split on the extension. 'addExtension' is the inverse. -- -- > uncurry (++) (splitExtension x) == x -- > uncurry addExtension (splitExtension x) == x -- > splitExtension "file.txt" == ("file",".txt") -- > splitExtension "file" == ("file","") -- > splitExtension "file/file.txt" == ("file/file",".txt") -- > splitExtension "file.txt/boris" == ("file.txt/boris","") -- > splitExtension "file.txt/boris.ext" == ("file.txt/boris",".ext") -- > splitExtension "file/path.txt.bob.fred" == ("file/path.txt.bob",".fred") -- > splitExtension "file/path.txt/" == ("file/path.txt/","") splitExtension :: FilePath -> (String, String) splitExtension x = case d of [] -> (x,"") (y:ys) -> (a ++ reverse ys, y : reverse c) where (a,b) = splitFileName_ x (c,d) = break isExtSeparator $ reverse b -- | Get the extension of a file, returns @\"\"@ for no extension, @.ext@ otherwise. -- -- > takeExtension x == snd (splitExtension x) -- > Valid x => takeExtension (addExtension x "ext") == ".ext" -- > Valid x => takeExtension (replaceExtension x "ext") == ".ext" takeExtension :: FilePath -> String takeExtension = snd . splitExtension -- | Set the extension of a file, overwriting one if already present. -- -- > replaceExtension "file.txt" ".bob" == "file.bob" -- > replaceExtension "file.txt" "bob" == "file.bob" -- > replaceExtension "file" ".bob" == "file.bob" -- > replaceExtension "file.txt" "" == "file" -- > replaceExtension "file.fred.bob" "txt" == "file.fred.txt" replaceExtension :: FilePath -> String -> FilePath replaceExtension x y = dropExtension x <.> y -- | Alias to 'addExtension', for people who like that sort of thing. (<.>) :: FilePath -> String -> FilePath (<.>) = addExtension -- | Remove last extension, and the \".\" preceding it. -- -- > dropExtension x == fst (splitExtension x) dropExtension :: FilePath -> FilePath dropExtension = fst . splitExtension -- | Add an extension, even if there is already one there. -- E.g. @addExtension \"foo.txt\" \"bat\" -> \"foo.txt.bat\"@. -- -- > addExtension "file.txt" "bib" == "file.txt.bib" -- > addExtension "file." ".bib" == "file..bib" -- > addExtension "file" ".bib" == "file.bib" -- > addExtension "/" "x" == "/.x" -- > Valid x => takeFileName (addExtension (addTrailingPathSeparator x) "ext") == ".ext" -- > Windows: addExtension "\\\\share" ".txt" == "\\\\share\\.txt" addExtension :: FilePath -> String -> FilePath addExtension file [] = file addExtension file xs@(x:_) = joinDrive a res where res = if isExtSeparator x then b ++ xs else b ++ [extSeparator] ++ xs (a,b) = splitDrive file -- | Does the given filename have an extension? -- -- > null (takeExtension x) == not (hasExtension x) hasExtension :: FilePath -> Bool hasExtension = any isExtSeparator . takeFileName -- | Split on all extensions -- -- > uncurry (++) (splitExtensions x) == x -- > uncurry addExtension (splitExtensions x) == x -- > splitExtensions "file.tar.gz" == ("file",".tar.gz") splitExtensions :: FilePath -> (FilePath, String) splitExtensions x = (a ++ c, d) where (a,b) = splitFileName_ x (c,d) = break isExtSeparator b -- | Drop all extensions -- -- > not $ hasExtension (dropExtensions x) dropExtensions :: FilePath -> FilePath dropExtensions = fst . splitExtensions -- | Get all extensions -- -- > takeExtensions "file.tar.gz" == ".tar.gz" takeExtensions :: FilePath -> String takeExtensions = snd . splitExtensions -- | Does the given filename have the specified extension? -- -- > "png" `isExtensionOf` "/directory/file.png" == True -- > ".png" `isExtensionOf` "/directory/file.png" == True -- > ".tar.gz" `isExtensionOf` "bar/foo.tar.gz" == True -- > "ar.gz" `isExtensionOf` "bar/foo.tar.gz" == False -- > "png" `isExtensionOf` "/directory/file.png.jpg" == False -- > "csv/table.csv" `isExtensionOf` "/data/csv/table.csv" == False isExtensionOf :: String -> FilePath -> Bool isExtensionOf extension path = case extension of ext@('.':_) -> isSuffixOf ext $ takeExtensions path ext -> isSuffixOf ('.':ext) $ takeExtensions path --------------------------------------------------------------------- -- Drive methods -- | Is the given character a valid drive letter? -- only a-z and A-Z are letters, not isAlpha which is more unicodey isLetter :: Char -> Bool isLetter x = (x >= 'a' && x <= 'z') || (x >= 'A' && x <= 'Z') -- | Split a path into a drive and a path. -- On Unix, \/ is a Drive. -- -- > uncurry (++) (splitDrive x) == x -- > Windows: splitDrive "file" == ("","file") -- > Windows: splitDrive "c:/file" == ("c:/","file") -- > Windows: splitDrive "c:\\file" == ("c:\\","file") -- > Windows: splitDrive "\\\\shared\\test" == ("\\\\shared\\","test") -- > Windows: splitDrive "\\\\shared" == ("\\\\shared","") -- > Windows: splitDrive "\\\\?\\UNC\\shared\\file" == ("\\\\?\\UNC\\shared\\","file") -- > Windows: splitDrive "\\\\?\\UNCshared\\file" == ("\\\\?\\","UNCshared\\file") -- > Windows: splitDrive "\\\\?\\d:\\file" == ("\\\\?\\d:\\","file") -- > Windows: splitDrive "/d" == ("","/d") -- > Posix: splitDrive "/test" == ("/","test") -- > Posix: splitDrive "//test" == ("//","test") -- > Posix: splitDrive "test/file" == ("","test/file") -- > Posix: splitDrive "file" == ("","file") splitDrive :: FilePath -> (FilePath, FilePath) splitDrive x | isPosix = span (== '/') x | isJust dl = fromJust dl | isJust unc = fromJust unc | isJust shr = fromJust shr | otherwise = ("",x) where dl = readDriveLetter x unc = readDriveUNC x shr = readDriveShare x addSlash :: FilePath -> FilePath -> (FilePath, FilePath) addSlash a xs = (a++c,d) where (c,d) = span isPathSeparator xs -- http://msdn.microsoft.com/library/default.asp?url=/library/en-us/fileio/fs/naming_a_file.asp -- "\\?\D:\<path>" or "\\?\UNC\<server>\<share>" -- a is "\\?\" readDriveUNC :: FilePath -> Maybe (FilePath, FilePath) readDriveUNC path = case path of (s1:s2:'?':s3:xs) -> if all isPathSeparator [s1,s2,s3] then let rdl = case readDriveLetter xs of Just (a,b) -> Just (s1:s2:'?':s3:a,b) Nothing -> Nothing in case map toUpper xs of ('U':'N':'C':s4:_) -> if isPathSeparator s4 then let (a,b) = readDriveShareName (drop 4 xs) in Just (s1:s2:'?':s3:take 4 xs ++ a, b) else rdl _ -> rdl else Nothing _ -> Nothing {- c:\ -} readDriveLetter :: String -> Maybe (FilePath, FilePath) readDriveLetter path = case path of (x:':':y:xs) -> if isLetter x && isPathSeparator y then Just $ addSlash [x,':'] (y:xs) else if isLetter x then Just ([x,':'], (y:xs)) else Nothing (x:':':xs) -> if isLetter x then Just ([x,':'], xs) else Nothing _ -> Nothing {- \\sharename\ -} readDriveShare :: String -> Maybe (FilePath, FilePath) path = case path of (s1:s2:xs) -> if isPathSeparator s1 && isPathSeparator s2 then let (a,b) = readDriveShareName xs in Just (s1:s2:a,b) else Nothing _ -> Nothing {- assume you have already seen \\ -} {- share\bob -> "share","\","bob" -} readDriveShareName :: String -> (FilePath, FilePath) name = addSlash a b where (a,b) = break isPathSeparator name -- | Join a drive and the rest of the path. -- -- > uncurry joinDrive (splitDrive x) == x -- > Windows: joinDrive "C:" "foo" == "C:foo" -- > Windows: joinDrive "C:\\" "bar" == "C:\\bar" -- > Windows: joinDrive "\\\\share" "foo" == "\\\\share\\foo" -- > Windows: joinDrive "/:" "foo" == "/:\\foo" joinDrive :: FilePath -> FilePath -> FilePath joinDrive a b | isPosix = a ++ b | null a = b | null b = a | isPathSeparator (last a) = a ++ b | otherwise = case a of [a1,':'] -> if isLetter a1 then a ++ b else a ++ [pathSeparator] ++ b _ -> a ++ [pathSeparator] ++ b -- | Get the drive from a filepath. -- -- > takeDrive x == fst (splitDrive x) takeDrive :: FilePath -> FilePath takeDrive = fst . splitDrive -- | Delete the drive, if it exists. -- -- > dropDrive x == snd (splitDrive x) dropDrive :: FilePath -> FilePath dropDrive = snd . splitDrive -- | Does a path have a drive. -- -- > not (hasDrive x) == null (takeDrive x) hasDrive :: FilePath -> Bool hasDrive = not . null . takeDrive -- | Is an element a drive isDrive :: FilePath -> Bool isDrive = null . dropDrive --------------------------------------------------------------------- -- Operations on a filepath, as a list of directories -- | Split a filename into directory and file. 'combine' is the inverse. -- -- > Valid x => uncurry (</>) (splitFileName x) == x || fst (splitFileName x) == "./" -- > Valid x => isValid (fst (splitFileName x)) -- > splitFileName "file/bob.txt" == ("file/", "bob.txt") -- > splitFileName "file/" == ("file/", "") -- > splitFileName "bob" == ("./", "bob") -- > Posix: splitFileName "/" == ("/","") -- > Windows: splitFileName "c:" == ("c:","") splitFileName :: FilePath -> (String, String) splitFileName x = (if null dir then "./" else dir, name) where (dir, name) = splitFileName_ x -- version of splitFileName where, if the FilePath has no directory -- component, the returned directory is "" rather than "./". This -- is used in cases where we are going to combine the returned -- directory to make a valid FilePath, and having a "./" appear would -- look strange and upset simple equality properties. See -- e.g. replaceFileName. splitFileName_ :: FilePath -> (String, String) splitFileName_ x = (c ++ reverse b, reverse a) where (a,b) = break isPathSeparator $ reverse d (c,d) = splitDrive x -- | Set the filename. -- -- > Valid x => replaceFileName x (takeFileName x) == x replaceFileName :: FilePath -> String -> FilePath replaceFileName x y = a </> y where (a,_) = splitFileName_ x -- | Drop the filename. -- -- > dropFileName x == fst (splitFileName x) dropFileName :: FilePath -> FilePath dropFileName = fst . splitFileName -- | Get the file name. -- -- > takeFileName "test/" == "" -- > takeFileName x `isSuffixOf` x -- > takeFileName x == snd (splitFileName x) -- > Valid x => takeFileName (replaceFileName x "fred") == "fred" -- > Valid x => takeFileName (x </> "fred") == "fred" -- > Valid x => isRelative (takeFileName x) takeFileName :: FilePath -> FilePath takeFileName = snd . splitFileName -- | Get the base name, without an extension or path. -- -- > takeBaseName "file/test.txt" == "test" -- > takeBaseName "dave.ext" == "dave" -- > takeBaseName "" == "" -- > takeBaseName "test" == "test" -- > takeBaseName (addTrailingPathSeparator x) == "" -- > takeBaseName "file/file.tar.gz" == "file.tar" takeBaseName :: FilePath -> String takeBaseName = dropExtension . takeFileName -- | Set the base name. -- -- > replaceBaseName "file/test.txt" "bob" == "file/bob.txt" -- > replaceBaseName "fred" "bill" == "bill" -- > replaceBaseName "/dave/fred/bob.gz.tar" "new" == "/dave/fred/new.tar" -- > Valid x => replaceBaseName x (takeBaseName x) == x replaceBaseName :: FilePath -> String -> FilePath replaceBaseName pth nam = combineAlways a (nam <.> ext) where (a,b) = splitFileName_ pth ext = takeExtension b -- | Is an item either a directory or the last character a path separator? -- -- > hasTrailingPathSeparator "test" == False -- > hasTrailingPathSeparator "test/" == True hasTrailingPathSeparator :: FilePath -> Bool hasTrailingPathSeparator [] = False hasTrailingPathSeparator x@(_:_) = isPathSeparator (last x) -- | Add a trailing file path separator if one is not already present. -- -- > hasTrailingPathSeparator (addTrailingPathSeparator x) -- > hasTrailingPathSeparator x ==> addTrailingPathSeparator x == x -- > Posix: addTrailingPathSeparator "test/rest" == "test/rest/" addTrailingPathSeparator :: FilePath -> FilePath addTrailingPathSeparator x = if hasTrailingPathSeparator x then x else x ++ [pathSeparator] -- | Remove any trailing path separators -- -- > dropTrailingPathSeparator "file/test/" == "file/test" -- > Posix: not (hasTrailingPathSeparator (dropTrailingPathSeparator x)) || isDrive x -- > Posix: dropTrailingPathSeparator "/" == "/" -- > Windows: dropTrailingPathSeparator "\\" == "\\" dropTrailingPathSeparator :: FilePath -> FilePath dropTrailingPathSeparator x = if hasTrailingPathSeparator x && not (isDrive x) then let x' = reverse $ dropWhile isPathSeparator $ reverse x in if null x' then [pathSeparator] else x' else x -- | Get the directory name, move up one level. -- -- > takeDirectory x `isPrefixOf` x || takeDirectory x == "." -- > takeDirectory "foo" == "." -- > takeDirectory "/foo/bar/baz" == "/foo/bar" -- > takeDirectory "/foo/bar/baz/" == "/foo/bar/baz" -- > takeDirectory "foo/bar/baz" == "foo/bar" -- > Windows: takeDirectory "foo\\bar" == "foo" -- > Windows: takeDirectory "foo\\bar\\\\" == "foo\\bar" -- > Windows: takeDirectory "C:\\" == "C:\\" takeDirectory :: FilePath -> FilePath takeDirectory x = if isDrive file then file else if null res && not (null file) then file else res where res = reverse $ dropWhile isPathSeparator $ reverse file file = dropFileName x _ = isPrefixOf x -- warning suppression -- | Set the directory, keeping the filename the same. -- -- > Valid x => replaceDirectory x (takeDirectory x) `equalFilePath` x replaceDirectory :: FilePath -> String -> FilePath replaceDirectory x dir = combineAlways dir (takeFileName x) -- | Combine two paths, if the second path 'isAbsolute', then it returns the second. -- -- > Valid x => combine (takeDirectory x) (takeFileName x) `equalFilePath` x -- > Posix: combine "/" "test" == "/test" -- > Posix: combine "home" "bob" == "home/bob" -- > Windows: combine "home" "bob" == "home\\bob" -- > Windows: combine "home" "/bob" == "/bob" combine :: FilePath -> FilePath -> FilePath combine a b | hasDrive b || (not (null b) && isPathSeparator (head b)) = b | otherwise = combineAlways a b -- | Combine two paths, assuming rhs is NOT absolute. combineAlways :: FilePath -> FilePath -> FilePath combineAlways a b | null a = b | null b = a | isPathSeparator (last a) = a ++ b | isDrive a = joinDrive a b | otherwise = a ++ [pathSeparator] ++ b -- | A nice alias for 'combine'. (</>) :: FilePath -> FilePath -> FilePath (</>) = combine -- | Split a path by the directory separator. -- -- > concat (splitPath x) == x -- > splitPath "test//item/" == ["test//","item/"] -- > splitPath "test/item/file" == ["test/","item/","file"] -- > splitPath "" == [] -- > Windows: splitPath "c:\\test\\path" == ["c:\\","test\\","path"] -- > Posix: splitPath "/file/test" == ["/","file/","test"] splitPath :: FilePath -> [FilePath] splitPath x = [drive | drive /= ""] ++ f path where (drive,path) = splitDrive x f [] = [] f y@(_:_) = (a ++ c) : f d where (a,b) = break isPathSeparator y (c,d) = break (not . isPathSeparator) b -- | Just as 'splitPath', but don't add the trailing slashes to each element. -- -- > splitDirectories "test/file" == ["test","file"] -- > splitDirectories "/test/file" == ["/","test","file"] -- > Valid x => joinPath (splitDirectories x) `equalFilePath` x -- > splitDirectories "" == [] splitDirectories :: FilePath -> [FilePath] splitDirectories path = if hasDrive path then head pathComponents : f (tail pathComponents) else f pathComponents where pathComponents = splitPath path f xs = map g xs g x = if null res then x else res where res = takeWhile (not . isPathSeparator) x -- | Join path elements back together. -- -- > Valid x => joinPath (splitPath x) == x -- > joinPath [] == "" -- > Posix: joinPath ["test","file","path"] == "test/file/path" -- Note that this definition on c:\\c:\\, join then split will give c:\\. joinPath :: [FilePath] -> FilePath joinPath x = foldr combine "" x --------------------------------------------------------------------- -- File name manipulators -- | Equality of two 'FilePath's. -- If you call @System.Directory.canonicalizePath@ -- first this has a much better chance of working. -- Note that this doesn't follow symlinks or DOSNAM~1s. -- -- > x == y ==> equalFilePath x y -- > normalise x == normalise y ==> equalFilePath x y -- > Posix: equalFilePath "foo" "foo/" -- > Posix: not (equalFilePath "foo" "/foo") -- > Posix: not (equalFilePath "foo" "FOO") -- > Windows: equalFilePath "foo" "FOO" equalFilePath :: FilePath -> FilePath -> Bool equalFilePath a b = f a == f b where f x | isWindows = dropTrailSlash $ map toLower $ normalise x | otherwise = dropTrailSlash $ normalise x dropTrailSlash x | length x >= 2 && isPathSeparator (last x) = init x | otherwise = x -- | Contract a filename, based on a relative path. -- -- There is no corresponding @makeAbsolute@ function, instead use -- @System.Directory.canonicalizePath@ which has the same effect. -- -- > Valid y => equalFilePath x y || (isRelative x && makeRelative y x == x) || equalFilePath (y </> makeRelative y x) x -- > makeRelative x x == "." -- > null y || equalFilePath (makeRelative x (x </> y)) y || null (takeFileName x) -- > Windows: makeRelative "C:\\Home" "c:\\home\\bob" == "bob" -- > Windows: makeRelative "C:\\Home" "c:/home/bob" == "bob" -- > Windows: makeRelative "C:\\Home" "D:\\Home\\Bob" == "D:\\Home\\Bob" -- > Windows: makeRelative "C:\\Home" "C:Home\\Bob" == "C:Home\\Bob" -- > Windows: makeRelative "/Home" "/home/bob" == "bob" -- > Posix: makeRelative "/Home" "/home/bob" == "/home/bob" -- > Posix: makeRelative "/home/" "/home/bob/foo/bar" == "bob/foo/bar" -- > Posix: makeRelative "/fred" "bob" == "bob" -- > Posix: makeRelative "/file/test" "/file/test/fred" == "fred" -- > Posix: makeRelative "/file/test" "/file/test/fred/" == "fred/" -- > Posix: makeRelative "some/path" "some/path/a/b/c" == "a/b/c" makeRelative :: FilePath -> FilePath -> FilePath makeRelative root path | equalFilePath root path = "." | takeAbs root /= takeAbs path = path | otherwise = f (dropAbs root) (dropAbs path) where f [] y = dropWhile isPathSeparator y f x@(_:_) y = let (x1,x2) = g x (y1,y2) = g y in if equalFilePath x1 y1 then f x2 y2 else path g x = (dropWhile isPathSeparator a, dropWhile isPathSeparator b) where (a,b) = break isPathSeparator $ dropWhile isPathSeparator x -- on windows, need to drop '/' which is kind of absolute, but not a drive dropAbs [] = dropDrive [] dropAbs (x:xs) | isPathSeparator x = xs | otherwise = dropDrive (x:xs) takeAbs [] = map (\y -> if isPathSeparator y then pathSeparator else toLower y) $ takeDrive [] takeAbs xs@(x:_) | isPathSeparator x = [pathSeparator] | otherwise = map (\y -> if isPathSeparator y then pathSeparator else toLower y) $ takeDrive xs -- | Normalise a file -- -- * \/\/ outside of the drive can be made blank -- -- * \/ -> 'pathSeparator' -- -- * .\/ -> \"\" -- -- > Posix: normalise "/file/\\test////" == "/file/\\test/" -- > Posix: normalise "/file/./test" == "/file/test" -- > Posix: normalise "/test/file/../bob/fred/" == "/test/file/../bob/fred/" -- > Posix: normalise "../bob/fred/" == "../bob/fred/" -- > Posix: normalise "./bob/fred/" == "bob/fred/" -- > Windows: normalise "c:\\file/bob\\" == "C:\\file\\bob\\" -- > Windows: normalise "c:\\" == "C:\\" -- > Windows: normalise "\\\\server\\test" == "\\\\server\\test" -- > Windows: normalise "c:/file" == "C:\\file" -- > normalise "." == "." -- > Posix: normalise "./" == "./" -- > Posix: normalise "./." == "./" -- > Posix: normalise "bob/fred/." == "bob/fred/" normalise :: FilePath -> FilePath normalise path = joinDrive (normaliseDrive drv) (f pth) ++ [pathSeparator | isDirPath pth] where (drv,pth) = splitDrive path isDirPath xs = lastSep xs || not (null xs) && last xs == '.' && lastSep (init xs) lastSep xs = not (null xs) && isPathSeparator (last xs) f = joinPath . dropDots . splitDirectories . propSep propSep [] = [] propSep xs@[x] | isPathSeparator x = [pathSeparator] | otherwise = xs propSep (x:y:xs) | isPathSeparator x && isPathSeparator y = propSep (x:xs) | isPathSeparator x = pathSeparator : propSep (y:xs) | otherwise = x : propSep (y:xs) dropDots xs | all (== ".") xs = ["."] | otherwise = dropDots' [] xs dropDots' acc [] = reverse acc dropDots' acc (x:xs) | x == "." = dropDots' acc xs | otherwise = dropDots' (x:acc) xs normaliseDrive :: FilePath -> FilePath normaliseDrive drive | isPosix = drive | otherwise = if isJust $ readDriveLetter x2 then map toUpper x2 else drive where x2 = map repSlash drive repSlash x = if isPathSeparator x then pathSeparator else x -- information for validity functions on Windows -- see http://msdn.microsoft.com/library/default.asp?url=/library/en-us/fileio/fs/naming_a_file.asp badCharacters :: [Char] badCharacters = ":*?><|\"" badElements :: [FilePath] badElements = ["CON", "PRN", "AUX", "NUL", "COM1", "COM2", "COM3", "COM4", "COM5", "COM6", "COM7", "COM8", "COM9", "LPT1", "LPT2", "LPT3", "LPT4", "LPT5", "LPT6", "LPT7", "LPT8", "LPT9", "CLOCK$"] -- | Is a FilePath valid, i.e. could you create a file like it? -- -- > isValid "" == False -- > Posix: isValid "/random_ path:*" == True -- > Posix: isValid x == not (null x) -- > Windows: isValid "c:\\test" == True -- > Windows: isValid "c:\\test:of_test" == False -- > Windows: isValid "test*" == False -- > Windows: isValid "c:\\test\\nul" == False -- > Windows: isValid "c:\\test\\prn.txt" == False -- > Windows: isValid "c:\\nul\\file" == False -- > Windows: isValid "\\\\" == False isValid :: FilePath -> Bool isValid [] = False isValid path@(_:_) | isPosix = True | otherwise = not (any (`elem` badCharacters) x2) && not (any f $ splitDirectories x2) && not (length path >= 2 && all isPathSeparator path) where x2 = dropDrive path f x = map toUpper (dropExtensions x) `elem` badElements -- | Take a FilePath and make it valid; does not change already valid FilePaths. -- -- > isValid (makeValid x) -- > isValid x ==> makeValid x == x -- > makeValid "" == "_" -- > Windows: makeValid "c:\\test:of_test" == "c:\\test_of_test" -- > Windows: makeValid "test*" == "test_" -- > Windows: makeValid "c:\\test\\nul" == "c:\\test\\nul_" -- > Windows: makeValid "c:\\test\\prn.txt" == "c:\\test\\prn_.txt" -- > Windows: makeValid "c:\\test/prn.txt" == "c:\\test/prn_.txt" -- > Windows: makeValid "c:\\nul\\file" == "c:\\nul_\\file" makeValid :: FilePath -> FilePath makeValid [] = "_" makeValid path@(_:_) | isPosix = path | length path >= 2 && all isPathSeparator path = take 2 path ++ "drive" | otherwise = joinDrive drv $ validElements $ validChars pth where (drv,pth) = splitDrive path validChars x = map f x f x | x `elem` badCharacters = '_' | otherwise = x validElements x = joinPath $ map g $ splitPath x g x = h (reverse b) ++ reverse a where (a,b) = span isPathSeparator $ reverse x h x = if map toUpper a `elem` badElements then a ++ "_" <.> b else x where (a,b) = splitExtensions x -- | Is a path relative, or is it fixed to the root? -- -- > Windows: isRelative "path\\test" == True -- > Windows: isRelative "c:\\test" == False -- > Windows: isRelative "c:test" == True -- > Windows: isRelative "c:" == True -- > Windows: isRelative "\\\\foo" == False -- > Windows: isRelative "/foo" == True -- > Posix: isRelative "test/path" == True -- > Posix: isRelative "/test" == False isRelative :: FilePath -> Bool isRelative = isRelativeDrive . takeDrive -- > isRelativeDrive "" == True -- > Windows: isRelativeDrive "c:\\" == False -- > Windows: isRelativeDrive "c:/" == False -- > Windows: isRelativeDrive "c:" == True -- > Windows: isRelativeDrive "\\\\foo" == False -- > Posix: isRelativeDrive "/" == False isRelativeDrive :: String -> Bool isRelativeDrive x = null x || maybe False (not . isPathSeparator . last . fst) (readDriveLetter x) -- | @not . 'isRelative'@ -- -- > isAbsolute x == not (isRelative x) isAbsolute :: FilePath -> Bool isAbsolute = not . isRelative |