Safe Haskell	None
Language	Haskell2010

File

Contents

File path
File handle
Re-exports

Synopsis

type FilePath = String
data Handle
stdin :: Handle
stdout :: Handle
stderr :: Handle
hFileSize :: MonadIO m => Handle -> m Integer
hGetEcho :: MonadIO m => Handle -> m Bool
hGetPosn :: Handle -> IO HandlePosn
hIsClosed :: MonadIO m => Handle -> m Bool
hIsEOF :: MonadIO m => Handle -> m Bool
hIsOpen :: MonadIO m => Handle -> m Bool
hIsReadable :: MonadIO m => Handle -> m Bool
hIsSeekable :: MonadIO m => Handle -> m Bool
hIsTerminalDevice :: MonadIO m => Handle -> m Bool
hIsWritable :: MonadIO m => Handle -> m Bool
hReady :: MonadIO m => Handle -> m Bool
hShow :: Handle -> IO String
hTell :: MonadIO m => Handle -> m Integer
hWaitForInput :: MonadIO m => Handle -> Int -> m Bool
hClose :: MonadIO m => Handle -> m ()
hFlush :: MonadIO m => Handle -> m ()
hSeek :: MonadIO m => Handle -> SeekMode -> Integer -> m ()
hSetBinaryMode :: Handle -> Bool -> IO ()
hSetBuffering :: MonadIO m => Handle -> BufferMode -> m ()
hSetEcho :: MonadIO m => Handle -> Bool -> m ()
hSetFileSize :: MonadIO m => Handle -> Integer -> m ()
hSetPosn :: HandlePosn -> IO ()
data BufferMode
- = NoBuffering
- | LineBuffering
- | BlockBuffering (Maybe Int)
data HandlePosn
data IOMode
- = ReadMode
- | WriteMode
- | AppendMode
- | ReadWriteMode
data SeekMode
- = AbsoluteSeek
- | RelativeSeek
- | SeekFromEnd
(</>) :: FilePath -> FilePath -> FilePath
makeRelative :: FilePath -> FilePath -> FilePath
dropTrailingPathSeparator :: FilePath -> FilePath
normalise :: FilePath -> FilePath
isAbsolute :: FilePath -> Bool
isRelative :: FilePath -> Bool
makeValid :: FilePath -> FilePath
isValid :: FilePath -> Bool
equalFilePath :: FilePath -> FilePath -> Bool
joinPath :: [FilePath] -> FilePath
splitDirectories :: FilePath -> [FilePath]
splitPath :: FilePath -> [FilePath]
combine :: FilePath -> FilePath -> FilePath
replaceDirectory :: FilePath -> String -> FilePath
takeDirectory :: FilePath -> FilePath
addTrailingPathSeparator :: FilePath -> FilePath
hasTrailingPathSeparator :: FilePath -> Bool
replaceBaseName :: FilePath -> String -> FilePath
takeBaseName :: FilePath -> String
takeFileName :: FilePath -> FilePath
dropFileName :: FilePath -> FilePath
replaceFileName :: FilePath -> String -> FilePath
splitFileName :: FilePath -> (String, String)
isDrive :: FilePath -> Bool
hasDrive :: FilePath -> Bool
dropDrive :: FilePath -> FilePath
takeDrive :: FilePath -> FilePath
joinDrive :: FilePath -> FilePath -> FilePath
splitDrive :: FilePath -> (FilePath, FilePath)
replaceExtensions :: FilePath -> String -> FilePath
takeExtensions :: FilePath -> String
dropExtensions :: FilePath -> FilePath
splitExtensions :: FilePath -> (FilePath, String)
stripExtension :: String -> FilePath -> Maybe FilePath
isExtensionOf :: String -> FilePath -> Bool
hasExtension :: FilePath -> Bool
addExtension :: FilePath -> String -> FilePath
dropExtension :: FilePath -> FilePath
(<.>) :: FilePath -> String -> FilePath
replaceExtension :: FilePath -> String -> FilePath
(-<.>) :: FilePath -> String -> FilePath
takeExtension :: FilePath -> String
splitExtension :: FilePath -> (String, String)
getSearchPath :: IO [FilePath]
splitSearchPath :: String -> [FilePath]
isExtSeparator :: Char -> Bool
extSeparator :: Char
isSearchPathSeparator :: Char -> Bool
searchPathSeparator :: Char
isPathSeparator :: Char -> Bool
pathSeparators :: [Char]
pathSeparator :: Char
module UnliftIO.Temporary
module UnliftIO.Directory

File path

type FilePath = String #

File and directory names are values of type String, whose precise meaning is operating system dependent. Files can be opened, yielding a handle which can then be used to operate on the contents of that file.

File handle

data Handle #

Haskell defines operations to read and write characters from and to files, represented by values of type Handle. Each value of this type is a handle: a record used by the Haskell run-time system to manage I/O with file system objects. A handle has at least the following properties:

whether it manages input or output or both;
whether it is open, closed or semi-closed;
whether the object is seekable;
whether buffering is disabled, or enabled on a line or block basis;
a buffer (whose length may be zero).

Most handles will also have a current I/O position indicating where the next input or output operation will occur. A handle is readable if it manages only input or both input and output; likewise, it is writable if it manages only output or both input and output. A handle is open when first allocated. Once it is closed it can no longer be used for either input or output, though an implementation cannot re-use its storage while references remain to it. Handles are in the Show and Eq classes. The string produced by showing a handle is system dependent; it should include enough information to identify the handle for debugging. A handle is equal according to == only to itself; no attempt is made to compare the internal state of different handles for equality.

Instances

Eq Handle	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Handle.Types Methods (==) :: Handle -> Handle -> Bool # (/=) :: Handle -> Handle -> Bool #
Show Handle	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Handle.Types Methods showsPrec :: Int -> Handle -> ShowS # show :: Handle -> String # showList :: [Handle] -> ShowS #

Standard file handles

stdin :: Handle #

A handle managing input from the Haskell program's standard input channel.

stdout :: Handle #

A handle managing output to the Haskell program's standard output channel.

stderr :: Handle #

A handle managing output to the Haskell program's standard error channel.

File handle queries

hFileSize :: MonadIO m => Handle -> m Integer #

Lifted version of hFileSize

Since: unliftio-0.2.1.0

hGetEcho :: MonadIO m => Handle -> m Bool #

Lifted version of hGetEcho

Since: unliftio-0.2.1.0

hGetPosn :: Handle -> IO HandlePosn #

Computation hGetPosn hdl returns the current I/O position of hdl as a value of the abstract type HandlePosn.

hIsClosed :: MonadIO m => Handle -> m Bool #

Lifted version of hIsClosed

Since: unliftio-0.2.1.0

hIsEOF :: MonadIO m => Handle -> m Bool #

Lifted version of hIsEOF

Since: unliftio-0.2.1.0

hIsOpen :: MonadIO m => Handle -> m Bool #

Lifted version of hIsOpen

Since: unliftio-0.2.1.0

hIsReadable :: MonadIO m => Handle -> m Bool #

Lifted version of hIsReadable

Since: unliftio-0.2.1.0

hIsSeekable :: MonadIO m => Handle -> m Bool #

Lifted version of hIsSeekable

Since: unliftio-0.2.1.0

hIsTerminalDevice :: MonadIO m => Handle -> m Bool #

Lifted version of hIsTerminalDevice

Since: unliftio-0.2.1.0

hIsWritable :: MonadIO m => Handle -> m Bool #

Lifted version of hIsWritable

Since: unliftio-0.2.1.0

hReady :: MonadIO m => Handle -> m Bool #

Lifted version of hReady

Since: unliftio-0.2.1.0

hShow :: Handle -> IO String #

hShow is in the IO monad, and gives more comprehensive output than the (pure) instance of Show for Handle.

hTell :: MonadIO m => Handle -> m Integer #

Lifted version of hTell

Since: unliftio-0.2.1.0

hWaitForInput :: MonadIO m => Handle -> Int -> m Bool #

Lifted version of hWaitForInput

Since: unliftio-0.2.1.0

File handle operations

hClose :: MonadIO m => Handle -> m () #

Lifted version of hClose

Since: unliftio-0.2.1.0

hFlush :: MonadIO m => Handle -> m () #

Lifted version of hFlush

Since: unliftio-0.2.1.0

hSeek :: MonadIO m => Handle -> SeekMode -> Integer -> m () #

Lifted version of hSeek

Since: unliftio-0.2.1.0

hSetBinaryMode :: Handle -> Bool -> IO () #

Select binary mode (True) or text mode (False) on a open handle. (See also openBinaryFile.)

This has the same effect as calling hSetEncoding with char8, together with hSetNewlineMode with noNewlineTranslation.

hSetBuffering :: MonadIO m => Handle -> BufferMode -> m () #

Lifted version of hSetBuffering

Since: unliftio-0.2.1.0

hSetEcho :: MonadIO m => Handle -> Bool -> m () #

Lifted version of hSetEcho

Since: unliftio-0.2.1.0

hSetFileSize :: MonadIO m => Handle -> Integer -> m () #

Lifted version of hSetFileSize

Since: unliftio-0.2.1.0

hSetPosn :: HandlePosn -> IO () #

If a call to hGetPosn hdl returns a position p, then computation hSetPosn p sets the position of hdl to the position it held at the time of the call to hGetPosn.

This operation may fail with:

isPermissionError if a system resource limit would be exceeded.

File handle types

data BufferMode #

Three kinds of buffering are supported: line-buffering, block-buffering or no-buffering. These modes have the following effects. For output, items are written out, or flushed, from the internal buffer according to the buffer mode:

line-buffering: the entire output buffer is flushed whenever a newline is output, the buffer overflows, a hFlush is issued, or the handle is closed.
block-buffering: the entire buffer is written out whenever it overflows, a hFlush is issued, or the handle is closed.
no-buffering: output is written immediately, and never stored in the buffer.

An implementation is free to flush the buffer more frequently, but not less frequently, than specified above. The output buffer is emptied as soon as it has been written out.

Similarly, input occurs according to the buffer mode for the handle:

line-buffering: when the buffer for the handle is not empty, the next item is obtained from the buffer; otherwise, when the buffer is empty, characters up to and including the next newline character are read into the buffer. No characters are available until the newline character is available or the buffer is full.
block-buffering: when the buffer for the handle becomes empty, the next block of data is read into the buffer.
no-buffering: the next input item is read and returned. The hLookAhead operation implies that even a no-buffered handle may require a one-character buffer.

The default buffering mode when a handle is opened is implementation-dependent and may depend on the file system object which is attached to that handle. For most implementations, physical files will normally be block-buffered and terminals will normally be line-buffered.

Constructors

NoBuffering	buffering is disabled if possible.
LineBuffering	line-buffering should be enabled if possible.
BlockBuffering (Maybe Int)	block-buffering should be enabled if possible. The size of the buffer is `n` items if the argument is `Just` `n` and is otherwise implementation-dependent.

Instances

Eq BufferMode
Instance details Defined in GHC.IO.Handle.Types Methods (==) :: BufferMode -> BufferMode -> Bool # (/=) :: BufferMode -> BufferMode -> Bool #
Ord BufferMode
Instance details Defined in GHC.IO.Handle.Types Methods compare :: BufferMode -> BufferMode -> Ordering # (<) :: BufferMode -> BufferMode -> Bool # (<=) :: BufferMode -> BufferMode -> Bool # (>) :: BufferMode -> BufferMode -> Bool # (>=) :: BufferMode -> BufferMode -> Bool # max :: BufferMode -> BufferMode -> BufferMode # min :: BufferMode -> BufferMode -> BufferMode #
Read BufferMode
Instance details Defined in GHC.IO.Handle.Types Methods readsPrec :: Int -> ReadS BufferMode # readList :: ReadS [BufferMode] # readPrec :: ReadPrec BufferMode # readListPrec :: ReadPrec [BufferMode] #
Show BufferMode
Instance details Defined in GHC.IO.Handle.Types Methods showsPrec :: Int -> BufferMode -> ShowS # show :: BufferMode -> String # showList :: [BufferMode] -> ShowS #

data HandlePosn #

Instances

Eq HandlePosn	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Handle Methods (==) :: HandlePosn -> HandlePosn -> Bool # (/=) :: HandlePosn -> HandlePosn -> Bool #
Show HandlePosn	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Handle Methods showsPrec :: Int -> HandlePosn -> ShowS # show :: HandlePosn -> String # showList :: [HandlePosn] -> ShowS #

data IOMode #

See openFile

Constructors

ReadMode
WriteMode
AppendMode
ReadWriteMode

Instances

Enum IOMode
Instance details Defined in GHC.IO.IOMode Methods succ :: IOMode -> IOMode # pred :: IOMode -> IOMode # toEnum :: Int -> IOMode # fromEnum :: IOMode -> Int # enumFrom :: IOMode -> [IOMode] # enumFromThen :: IOMode -> IOMode -> [IOMode] # enumFromTo :: IOMode -> IOMode -> [IOMode] # enumFromThenTo :: IOMode -> IOMode -> IOMode -> [IOMode] #
Eq IOMode
Instance details Defined in GHC.IO.IOMode Methods (==) :: IOMode -> IOMode -> Bool # (/=) :: IOMode -> IOMode -> Bool #
Ord IOMode
Instance details Defined in GHC.IO.IOMode Methods compare :: IOMode -> IOMode -> Ordering # (<) :: IOMode -> IOMode -> Bool # (<=) :: IOMode -> IOMode -> Bool # (>) :: IOMode -> IOMode -> Bool # (>=) :: IOMode -> IOMode -> Bool # max :: IOMode -> IOMode -> IOMode # min :: IOMode -> IOMode -> IOMode #
Read IOMode
Instance details Defined in GHC.IO.IOMode Methods readsPrec :: Int -> ReadS IOMode # readList :: ReadS [IOMode] # readPrec :: ReadPrec IOMode # readListPrec :: ReadPrec [IOMode] #
Show IOMode
Instance details Defined in GHC.IO.IOMode Methods showsPrec :: Int -> IOMode -> ShowS # show :: IOMode -> String # showList :: [IOMode] -> ShowS #
Ix IOMode
Instance details Defined in GHC.IO.IOMode Methods range :: (IOMode, IOMode) -> [IOMode] # index :: (IOMode, IOMode) -> IOMode -> Int # unsafeIndex :: (IOMode, IOMode) -> IOMode -> Int inRange :: (IOMode, IOMode) -> IOMode -> Bool # rangeSize :: (IOMode, IOMode) -> Int # unsafeRangeSize :: (IOMode, IOMode) -> Int

data SeekMode #

A mode that determines the effect of hSeek hdl mode i.

Constructors

AbsoluteSeek	the position of `hdl` is set to `i`.
RelativeSeek	the position of `hdl` is set to offset `i` from the current position.
SeekFromEnd	the position of `hdl` is set to offset `i` from the end of the file.

Instances

Enum SeekMode
Instance details Defined in GHC.IO.Device Methods succ :: SeekMode -> SeekMode # pred :: SeekMode -> SeekMode # toEnum :: Int -> SeekMode # fromEnum :: SeekMode -> Int # enumFrom :: SeekMode -> [SeekMode] # enumFromThen :: SeekMode -> SeekMode -> [SeekMode] # enumFromTo :: SeekMode -> SeekMode -> [SeekMode] # enumFromThenTo :: SeekMode -> SeekMode -> SeekMode -> [SeekMode] #
Eq SeekMode
Instance details Defined in GHC.IO.Device Methods (==) :: SeekMode -> SeekMode -> Bool # (/=) :: SeekMode -> SeekMode -> Bool #
Ord SeekMode
Instance details Defined in GHC.IO.Device Methods compare :: SeekMode -> SeekMode -> Ordering # (<) :: SeekMode -> SeekMode -> Bool # (<=) :: SeekMode -> SeekMode -> Bool # (>) :: SeekMode -> SeekMode -> Bool # (>=) :: SeekMode -> SeekMode -> Bool # max :: SeekMode -> SeekMode -> SeekMode # min :: SeekMode -> SeekMode -> SeekMode #
Read SeekMode
Instance details Defined in GHC.IO.Device Methods readsPrec :: Int -> ReadS SeekMode # readList :: ReadS [SeekMode] # readPrec :: ReadPrec SeekMode # readListPrec :: ReadPrec [SeekMode] #
Show SeekMode
Instance details Defined in GHC.IO.Device Methods showsPrec :: Int -> SeekMode -> ShowS # show :: SeekMode -> String # showList :: [SeekMode] -> ShowS #
Ix SeekMode
Instance details Defined in GHC.IO.Device Methods range :: (SeekMode, SeekMode) -> [SeekMode] # index :: (SeekMode, SeekMode) -> SeekMode -> Int # unsafeIndex :: (SeekMode, SeekMode) -> SeekMode -> Int inRange :: (SeekMode, SeekMode) -> SeekMode -> Bool # rangeSize :: (SeekMode, SeekMode) -> Int # unsafeRangeSize :: (SeekMode, SeekMode) -> Int

Re-exports

(</>) :: FilePath -> FilePath -> FilePath infixr 5 #

Combine two paths with a path separator. If the second path starts with a path separator or a drive letter, then it returns the second. The intention is that readFile (dir </> file) will access the same file as setCurrentDirectory dir; readFile file.

Posix:   "/directory" </> "file.ext" == "/directory/file.ext"
Windows: "/directory" </> "file.ext" == "/directory\\file.ext"
         "directory" </> "/file.ext" == "/file.ext"
Valid x => (takeDirectory x </> takeFileName x) `equalFilePath` x

Combined:

Posix:   "/" </> "test" == "/test"
Posix:   "home" </> "bob" == "home/bob"
Posix:   "x:" </> "foo" == "x:/foo"
Windows: "C:\\foo" </> "bar" == "C:\\foo\\bar"
Windows: "home" </> "bob" == "home\\bob"

Not combined:

Posix:   "home" </> "/bob" == "/bob"
Windows: "home" </> "C:\\bob" == "C:\\bob"

Not combined (tricky):

On Windows, if a filepath starts with a single slash, it is relative to the root of the current drive. In [1], this is (confusingly) referred to as an absolute path. The current behavior of </> is to never combine these forms.

Windows: "home" </> "/bob" == "/bob"
Windows: "home" </> "\\bob" == "\\bob"
Windows: "C:\\home" </> "\\bob" == "\\bob"

On Windows, from [1]: "If a file name begins with only a disk designator but not the backslash after the colon, it is interpreted as a relative path to the current directory on the drive with the specified letter." The current behavior of </> is to never combine these forms.

Windows: "D:\\foo" </> "C:bar" == "C:bar"
Windows: "C:\\foo" </> "C:bar" == "C:bar"

makeRelative :: FilePath -> FilePath -> FilePath #

Contract a filename, based on a relative path. Note that the resulting path will never introduce .. paths, as the presence of symlinks means ../b may not reach a/b if it starts from a/c. For a worked example see this blog post.

The corresponding makeAbsolute function can be found in System.Directory.

         makeRelative "/directory" "/directory/file.ext" == "file.ext"
         Valid x => makeRelative (takeDirectory x) x `equalFilePath` takeFileName x
         makeRelative x x == "."
         Valid x y => equalFilePath x y || (isRelative x && makeRelative y x == x) || equalFilePath (y </> makeRelative y x) 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"
Windows: makeRelative "/" "//" == "//"
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"

dropTrailingPathSeparator :: FilePath -> FilePath #

Remove any trailing path separators

dropTrailingPathSeparator "file/test/" == "file/test"
          dropTrailingPathSeparator "/" == "/"
Windows:  dropTrailingPathSeparator "\\" == "\\"
Posix:    not (hasTrailingPathSeparator (dropTrailingPathSeparator x)) || isDrive x

normalise :: FilePath -> FilePath #

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 "C:.\\" == "C:"
Windows: normalise "\\\\server\\test" == "\\\\server\\test"
Windows: normalise "//server/test" == "\\\\server\\test"
Windows: normalise "c:/file" == "C:\\file"
Windows: normalise "/file" == "\\file"
Windows: normalise "\\" == "\\"
Windows: normalise "/./" == "\\"
         normalise "." == "."
Posix:   normalise "./" == "./"
Posix:   normalise "./." == "./"
Posix:   normalise "/./" == "/"
Posix:   normalise "/" == "/"
Posix:   normalise "bob/fred/." == "bob/fred/"
Posix:   normalise "//home" == "/home"

isAbsolute :: FilePath -> Bool #

not . isRelative

isAbsolute x == not (isRelative x)

isRelative :: FilePath -> Bool #

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:\\" == False
Windows: isRelative "c:/" == False
Windows: isRelative "c:" == True
Windows: isRelative "\\\\foo" == False
Windows: isRelative "\\\\?\\foo" == False
Windows: isRelative "\\\\?\\UNC\\foo" == False
Windows: isRelative "/foo" == True
Windows: isRelative "\\foo" == True
Posix:   isRelative "test/path" == True
Posix:   isRelative "/test" == False
Posix:   isRelative "/" == False

According to [1]:

"A UNC name of any format [is never relative]."
"You cannot use the "\?" prefix with a relative path."

makeValid :: FilePath -> FilePath #

Take a FilePath and make it valid; does not change already valid FilePaths.

isValid (makeValid x)
isValid x ==> makeValid x == x
makeValid "" == "_"
makeValid "file\0name" == "file_name"
Windows: makeValid "c:\\already\\/valid" == "c:\\already\\/valid"
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"
Windows: makeValid "\\\\\\foo" == "\\\\drive"
Windows: makeValid "\\\\?\\D:file" == "\\\\?\\D:\\file"
Windows: makeValid "nul .txt" == "nul _.txt"

isValid :: FilePath -> Bool #

Is a FilePath valid, i.e. could you create a file like it? This function checks for invalid names, and invalid characters, but does not check if length limits are exceeded, as these are typically filesystem dependent.

         isValid "" == False
         isValid "\0" == 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
Windows: isValid "\\\\\\foo" == False
Windows: isValid "\\\\?\\D:file" == False
Windows: isValid "foo\tbar" == False
Windows: isValid "nul .txt" == False
Windows: isValid " nul.txt" == True

equalFilePath :: FilePath -> FilePath -> Bool #

Equality of two FilePaths. 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
         equalFilePath "foo" "foo/"
         not (equalFilePath "foo" "/foo")
Posix:   not (equalFilePath "foo" "FOO")
Windows: equalFilePath "foo" "FOO"
Windows: not (equalFilePath "C:" "C:/")

joinPath :: [FilePath] -> FilePath #

Join path elements back together.

joinPath ["/","directory/","file.ext"] == "/directory/file.ext"
Valid x => joinPath (splitPath x) == x
joinPath [] == ""
Posix: joinPath ["test","file","path"] == "test/file/path"

splitDirectories :: FilePath -> [FilePath] #

Just as splitPath, but don't add the trailing slashes to each element.

         splitDirectories "/directory/file.ext" == ["/","directory","file.ext"]
         splitDirectories "test/file" == ["test","file"]
         splitDirectories "/test/file" == ["/","test","file"]
Windows: splitDirectories "C:\\test\\file" == ["C:\\", "test", "file"]
         Valid x => joinPath (splitDirectories x) `equalFilePath` x
         splitDirectories "" == []
Windows: splitDirectories "C:\\test\\\\\\file" == ["C:\\", "test", "file"]
         splitDirectories "/test///file" == ["/","test","file"]

splitPath :: FilePath -> [FilePath] #

Split a path by the directory separator.

splitPath "/directory/file.ext" == ["/","directory/","file.ext"]
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"]

combine :: FilePath -> FilePath -> FilePath #

An alias for </>.

replaceDirectory :: FilePath -> String -> FilePath #

Set the directory, keeping the filename the same.

replaceDirectory "root/file.ext" "/directory/" == "/directory/file.ext"
Valid x => replaceDirectory x (takeDirectory x) `equalFilePath` x

takeDirectory :: FilePath -> FilePath #

Get the directory name, move up one level.

          takeDirectory "/directory/other.ext" == "/directory"
          takeDirectory x `isPrefixOf` x || takeDirectory x == "."
          takeDirectory "foo" == "."
          takeDirectory "/" == "/"
          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:\\"

addTrailingPathSeparator :: FilePath -> FilePath #

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/"

hasTrailingPathSeparator :: FilePath -> Bool #

Is an item either a directory or the last character a path separator?

hasTrailingPathSeparator "test" == False
hasTrailingPathSeparator "test/" == True

replaceBaseName :: FilePath -> String -> FilePath #

Set the base name.

replaceBaseName "/directory/other.ext" "file" == "/directory/file.ext"
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

takeBaseName :: FilePath -> String #

Get the base name, without an extension or path.

takeBaseName "/directory/file.ext" == "file"
takeBaseName "file/test.txt" == "test"
takeBaseName "dave.ext" == "dave"
takeBaseName "" == ""
takeBaseName "test" == "test"
takeBaseName (addTrailingPathSeparator x) == ""
takeBaseName "file/file.tar.gz" == "file.tar"

takeFileName :: FilePath -> FilePath #

Get the file name.

takeFileName "/directory/file.ext" == "file.ext"
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)

dropFileName :: FilePath -> FilePath #

Drop the filename. Unlike takeDirectory, this function will leave a trailing path separator on the directory.

dropFileName "/directory/file.ext" == "/directory/"
dropFileName x == fst (splitFileName x)

replaceFileName :: FilePath -> String -> FilePath #

Set the filename.

replaceFileName "/directory/other.txt" "file.ext" == "/directory/file.ext"
Valid x => replaceFileName x (takeFileName x) == x

splitFileName :: FilePath -> (String, String) #

Split a filename into directory and file. </> is the inverse. The first component will often end with a trailing slash.

splitFileName "/directory/file.ext" == ("/directory/","file.ext")
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:","")

isDrive :: FilePath -> Bool #

Is an element a drive

Posix:   isDrive "/" == True
Posix:   isDrive "/foo" == False
Windows: isDrive "C:\\" == True
Windows: isDrive "C:\\foo" == False
         isDrive "" == False

hasDrive :: FilePath -> Bool #

Does a path have a drive.

not (hasDrive x) == null (takeDrive x)
Posix:   hasDrive "/foo" == True
Windows: hasDrive "C:\\foo" == True
Windows: hasDrive "C:foo" == True
         hasDrive "foo" == False
         hasDrive "" == False

dropDrive :: FilePath -> FilePath #

Delete the drive, if it exists.

dropDrive x == snd (splitDrive x)

takeDrive :: FilePath -> FilePath #

Get the drive from a filepath.

takeDrive x == fst (splitDrive x)

joinDrive :: FilePath -> FilePath -> FilePath #

Join a drive and the rest of the path.

Valid x => 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"

splitDrive :: FilePath -> (FilePath, FilePath) #

Split a path into a drive and a path. On Posix, / 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")

replaceExtensions :: FilePath -> String -> FilePath #

Replace all extensions of a file with a new extension. Note that replaceExtension and addExtension both work for adding multiple extensions, so only required when you need to drop all extensions first.

replaceExtensions "file.fred.bob" "txt" == "file.txt"
replaceExtensions "file.fred.bob" "tar.gz" == "file.tar.gz"

takeExtensions :: FilePath -> String #

Get all extensions.

takeExtensions "/directory/path.ext" == ".ext"
takeExtensions "file.tar.gz" == ".tar.gz"

dropExtensions :: FilePath -> FilePath #

Drop all extensions.

dropExtensions "/directory/path.ext" == "/directory/path"
dropExtensions "file.tar.gz" == "file"
not $ hasExtension $ dropExtensions x
not $ any isExtSeparator $ takeFileName $ dropExtensions x

splitExtensions :: FilePath -> (FilePath, String) #

Split on all extensions.

splitExtensions "/directory/path.ext" == ("/directory/path",".ext")
splitExtensions "file.tar.gz" == ("file",".tar.gz")
uncurry (++) (splitExtensions x) == x
Valid x => uncurry addExtension (splitExtensions x) == x
splitExtensions "file.tar.gz" == ("file",".tar.gz")

stripExtension :: String -> FilePath -> Maybe FilePath #

Drop the given extension from a FilePath, and the "." preceding it. Returns Nothing if the FilePath does not have the given extension, or Just and the part before the extension if it does.

This function can be more predictable than dropExtensions, especially if the filename might itself contain . characters.

stripExtension "hs.o" "foo.x.hs.o" == Just "foo.x"
stripExtension "hi.o" "foo.x.hs.o" == Nothing
dropExtension x == fromJust (stripExtension (takeExtension x) x)
dropExtensions x == fromJust (stripExtension (takeExtensions x) x)
stripExtension ".c.d" "a.b.c.d"  == Just "a.b"
stripExtension ".c.d" "a.b..c.d" == Just "a.b."
stripExtension "baz"  "foo.bar"  == Nothing
stripExtension "bar"  "foobar"   == Nothing
stripExtension ""     x          == Just x

isExtensionOf :: String -> FilePath -> Bool #

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

hasExtension :: FilePath -> Bool #

Does the given filename have an extension?

hasExtension "/directory/path.ext" == True
hasExtension "/directory/path" == False
null (takeExtension x) == not (hasExtension x)

addExtension :: FilePath -> String -> FilePath #

Add an extension, even if there is already one there, equivalent to <.>.

addExtension "/directory/path" "ext" == "/directory/path.ext"
addExtension "file.txt" "bib" == "file.txt.bib"
addExtension "file." ".bib" == "file..bib"
addExtension "file" ".bib" == "file.bib"
addExtension "/" "x" == "/.x"
addExtension x "" == x
Valid x => takeFileName (addExtension (addTrailingPathSeparator x) "ext") == ".ext"
Windows: addExtension "\\\\share" ".txt" == "\\\\share\\.txt"

dropExtension :: FilePath -> FilePath #

Remove last extension, and the "." preceding it.

dropExtension "/directory/path.ext" == "/directory/path"
dropExtension x == fst (splitExtension x)

(<.>) :: FilePath -> String -> FilePath infixr 7 #

Add an extension, even if there is already one there, equivalent to addExtension.

"/directory/path" <.> "ext" == "/directory/path.ext"
"/directory/path" <.> ".ext" == "/directory/path.ext"

replaceExtension :: FilePath -> String -> FilePath #

Set the extension of a file, overwriting one if already present, equivalent to -<.>.

replaceExtension "/directory/path.txt" "ext" == "/directory/path.ext"
replaceExtension "/directory/path.txt" ".ext" == "/directory/path.ext"
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 x y == addExtension (dropExtension x) y

(-<.>) :: FilePath -> String -> FilePath infixr 7 #

Remove the current extension and add another, equivalent to replaceExtension.

"/directory/path.txt" -<.> "ext" == "/directory/path.ext"
"/directory/path.txt" -<.> ".ext" == "/directory/path.ext"
"foo.o" -<.> "c" == "foo.c"

takeExtension :: FilePath -> String #

Get the extension of a file, returns "" for no extension, .ext otherwise.

takeExtension "/directory/path.ext" == ".ext"
takeExtension x == snd (splitExtension x)
Valid x => takeExtension (addExtension x "ext") == ".ext"
Valid x => takeExtension (replaceExtension x "ext") == ".ext"

splitExtension :: FilePath -> (String, String) #

Split on the extension. addExtension is the inverse.

splitExtension "/directory/path.ext" == ("/directory/path",".ext")
uncurry (++) (splitExtension x) == x
Valid 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/","")

getSearchPath :: IO [FilePath] #

Get a list of FilePaths in the $PATH variable.

splitSearchPath :: String -> [FilePath] #

Take a string, split it on the searchPathSeparator character. Blank items are ignored on Windows, and converted to . on Posix. On Windows path elements are stripped of quotes.

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"]
Windows: splitSearchPath "File1;\"File2\";File3" == ["File1","File2","File3"]

isExtSeparator :: Char -> Bool #

Is the character an extension character?

isExtSeparator a == (a == extSeparator)

extSeparator :: Char #

File extension character

extSeparator == '.'

isSearchPathSeparator :: Char -> Bool #

Is the character a file separator?

isSearchPathSeparator a == (a == searchPathSeparator)

searchPathSeparator :: Char #

The character that is used to separate the entries in the $PATH environment variable.

Windows: searchPathSeparator == ';'
Posix:   searchPathSeparator == ':'

isPathSeparator :: Char -> Bool #

Rather than using (== pathSeparator), use this. Test if something is a path separator.

isPathSeparator a == (a `elem` pathSeparators)

pathSeparators :: [Char] #

The list of all possible separators.

Windows: pathSeparators == ['\\', '/']
Posix:   pathSeparators == ['/']
pathSeparator `elem` pathSeparators

pathSeparator :: Char #

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

module UnliftIO.Temporary

module UnliftIO.Directory