Copyright | (c) Neil Mitchell 2005-2014 |
---|---|
License | BSD3 |
Maintainer | ndmitchell@gmail.com |
Stability | stable |
Portability | portable |
Safe Haskell | Safe |
Language | Haskell2010 |
A library for FilePath
manipulations, using Posix style paths on
all platforms. Importing System.FilePath is usually better.
Given the example FilePath
: /directory/file.ext
We can use the following functions to extract pieces.
takeFileName
gives"file.ext"
takeDirectory
gives"/directory"
takeExtension
gives".ext"
dropExtension
gives"/directory/file"
takeBaseName
gives"file"
And we could have built an equivalent path with the following expressions:
Each function in this module is documented with several examples, which are also used as tests.
Here are a few examples of using the filepath
functions together:
Example 1: Find the possible locations of a Haskell module Test
imported from module Main
:
[replaceFileName
path_to_main "Test"<.>
ext | ext <- ["hs","lhs"] ]
Example 2: Download a file from url
and save it to disk:
do let file =makeValid
url System.Directory.createDirectoryIfMissing True (takeDirectory
file)
Example 3: Compile a Haskell file, putting the .hi
file under interface
:
takeDirectory
file</>
"interface"</>
(takeFileName
file-<.>
"hi")
References: [1] Naming Files, Paths and Namespaces (Microsoft MSDN)
Synopsis
- type FilePath = String
- pathSeparator :: Char
- pathSeparators :: [Char]
- isPathSeparator :: Char -> Bool
- searchPathSeparator :: Char
- isSearchPathSeparator :: Char -> Bool
- extSeparator :: Char
- isExtSeparator :: Char -> Bool
- splitSearchPath :: String -> [FilePath]
- getSearchPath :: IO [FilePath]
- splitExtension :: FilePath -> (String, String)
- takeExtension :: FilePath -> String
- replaceExtension :: FilePath -> String -> FilePath
- (-<.>) :: FilePath -> String -> FilePath
- dropExtension :: FilePath -> FilePath
- addExtension :: FilePath -> String -> FilePath
- hasExtension :: FilePath -> Bool
- (<.>) :: FilePath -> String -> FilePath
- splitExtensions :: FilePath -> (FilePath, String)
- dropExtensions :: FilePath -> FilePath
- takeExtensions :: FilePath -> String
- replaceExtensions :: FilePath -> String -> FilePath
- isExtensionOf :: String -> FilePath -> Bool
- stripExtension :: String -> FilePath -> Maybe FilePath
- splitFileName :: FilePath -> (String, String)
- takeFileName :: FilePath -> FilePath
- replaceFileName :: FilePath -> String -> FilePath
- dropFileName :: FilePath -> FilePath
- takeBaseName :: FilePath -> String
- replaceBaseName :: FilePath -> String -> FilePath
- takeDirectory :: FilePath -> FilePath
- replaceDirectory :: FilePath -> String -> FilePath
- combine :: FilePath -> FilePath -> FilePath
- (</>) :: FilePath -> FilePath -> FilePath
- splitPath :: FilePath -> [FilePath]
- joinPath :: [FilePath] -> FilePath
- splitDirectories :: FilePath -> [FilePath]
- splitDrive :: FilePath -> (FilePath, FilePath)
- joinDrive :: FilePath -> FilePath -> FilePath
- takeDrive :: FilePath -> FilePath
- hasDrive :: FilePath -> Bool
- dropDrive :: FilePath -> FilePath
- isDrive :: FilePath -> Bool
- hasTrailingPathSeparator :: FilePath -> Bool
- addTrailingPathSeparator :: FilePath -> FilePath
- dropTrailingPathSeparator :: FilePath -> FilePath
- normalise :: FilePath -> FilePath
- equalFilePath :: FilePath -> FilePath -> Bool
- makeRelative :: FilePath -> FilePath -> FilePath
- isRelative :: FilePath -> Bool
- isAbsolute :: FilePath -> Bool
- isValid :: FilePath -> Bool
- makeValid :: FilePath -> FilePath
Separator predicates
type FilePath = String Source #
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.
pathSeparator :: Char Source #
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
pathSeparators :: [Char] Source #
The list of all possible separators.
Windows: pathSeparators == ['\\', '/'] Posix: pathSeparators == ['/'] pathSeparator `elem` pathSeparators
isPathSeparator :: Char -> Bool Source #
Rather than using (==
, use this. Test if something
is a path separator.pathSeparator
)
isPathSeparator a == (a `elem` pathSeparators)
searchPathSeparator :: Char Source #
The character that is used to separate the entries in the $PATH environment variable.
Windows: searchPathSeparator == ';' Posix: searchPathSeparator == ':'
isSearchPathSeparator :: Char -> Bool Source #
Is the character a file separator?
isSearchPathSeparator a == (a == searchPathSeparator)
extSeparator :: Char Source #
File extension character
extSeparator == '.'
isExtSeparator :: Char -> Bool Source #
Is the character an extension character?
isExtSeparator a == (a == extSeparator)
$PATH
methods
splitSearchPath :: String -> [FilePath] Source #
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"]
Extension functions
splitExtension :: FilePath -> (String, String) Source #
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/","")
takeExtension :: FilePath -> String Source #
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"
replaceExtension :: FilePath -> String -> FilePath Source #
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 Source #
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"
dropExtension :: FilePath -> FilePath Source #
Remove last extension, and the "." preceding it.
dropExtension "/directory/path.ext" == "/directory/path" dropExtension x == fst (splitExtension x)
addExtension :: FilePath -> String -> FilePath Source #
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"
hasExtension :: FilePath -> Bool Source #
Does the given filename have an extension?
hasExtension "/directory/path.ext" == True hasExtension "/directory/path" == False null (takeExtension x) == not (hasExtension x)
(<.>) :: FilePath -> String -> FilePath infixr 7 Source #
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"
splitExtensions :: FilePath -> (FilePath, String) Source #
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")
dropExtensions :: FilePath -> FilePath Source #
Drop all extensions.
dropExtensions "/directory/path.ext" == "/directory/path" dropExtensions "file.tar.gz" == "file" not $ hasExtension $ dropExtensions x not $ any isExtSeparator $ takeFileName $ dropExtensions x
takeExtensions :: FilePath -> String Source #
Get all extensions.
takeExtensions "/directory/path.ext" == ".ext" takeExtensions "file.tar.gz" == ".tar.gz"
replaceExtensions :: FilePath -> String -> FilePath Source #
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"
isExtensionOf :: String -> FilePath -> Bool Source #
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
stripExtension :: String -> FilePath -> Maybe FilePath Source #
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
Filename/directory functions
splitFileName :: FilePath -> (String, String) Source #
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:","")
takeFileName :: FilePath -> FilePath Source #
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)
replaceFileName :: FilePath -> String -> FilePath Source #
Set the filename.
replaceFileName "/directory/other.txt" "file.ext" == "/directory/file.ext" Valid x => replaceFileName x (takeFileName x) == x
dropFileName :: FilePath -> FilePath Source #
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)
takeBaseName :: FilePath -> String Source #
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"
replaceBaseName :: FilePath -> String -> FilePath Source #
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
takeDirectory :: FilePath -> FilePath Source #
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:\\"
replaceDirectory :: FilePath -> String -> FilePath Source #
Set the directory, keeping the filename the same.
replaceDirectory "root/file.ext" "/directory/" == "/directory/file.ext" Valid x => replaceDirectory x (takeDirectory x) `equalFilePath` x
(</>) :: FilePath -> FilePath -> FilePath infixr 5 Source #
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
will access the same file as
</>
file)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"
splitPath :: FilePath -> [FilePath] Source #
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"]
joinPath :: [FilePath] -> FilePath Source #
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] Source #
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"]
Drive functions
splitDrive :: FilePath -> (FilePath, FilePath) Source #
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")
joinDrive :: FilePath -> FilePath -> FilePath Source #
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"
takeDrive :: FilePath -> FilePath Source #
Get the drive from a filepath.
takeDrive x == fst (splitDrive x)
hasDrive :: FilePath -> Bool Source #
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 Source #
Delete the drive, if it exists.
dropDrive x == snd (splitDrive x)
isDrive :: FilePath -> Bool Source #
Is an element a drive
Posix: isDrive "/" == True Posix: isDrive "/foo" == False Windows: isDrive "C:\\" == True Windows: isDrive "C:\\foo" == False isDrive "" == False
Trailing slash functions
hasTrailingPathSeparator :: FilePath -> Bool Source #
Is an item either a directory or the last character a path separator?
hasTrailingPathSeparator "test" == False hasTrailingPathSeparator "test/" == True
addTrailingPathSeparator :: FilePath -> FilePath Source #
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/"
dropTrailingPathSeparator :: FilePath -> FilePath Source #
Remove any trailing path separators
dropTrailingPathSeparator "file/test/" == "file/test" dropTrailingPathSeparator "/" == "/" Windows: dropTrailingPathSeparator "\\" == "\\" Posix: not (hasTrailingPathSeparator (dropTrailingPathSeparator x)) || isDrive x
File name manipulations
normalise :: FilePath -> FilePath Source #
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"
equalFilePath :: FilePath -> FilePath -> Bool Source #
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 equalFilePath "foo" "foo/" not (equalFilePath "foo" "/foo") Posix: not (equalFilePath "foo" "FOO") Windows: equalFilePath "foo" "FOO" Windows: not (equalFilePath "C:" "C:/")
makeRelative :: FilePath -> FilePath -> FilePath Source #
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"
isRelative :: FilePath -> Bool Source #
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."
isAbsolute :: FilePath -> Bool Source #
not . isRelative
isAbsolute x == not (isRelative x)
isValid :: FilePath -> Bool Source #
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
makeValid :: FilePath -> FilePath Source #
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"