| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Hackage.Security.Util.Path
Description
A more type-safe version of file paths
This module is intended to replace imports of System.FilePath, and additionally exports thin wrappers around common IO functions. To facilitate importing this module unqualified we also re-export some definitions from System.IO (importing both would likely lead to name clashes).
Note that his module does not import any other modules from Hackage.Security; everywhere else we use Path instead of FilePath directly.
Synopsis
- newtype Path a = Path FilePath
- castRoot :: Path root -> Path root'
- takeDirectory :: Path a -> Path a
- takeFileName :: Path a -> String
- (<.>) :: Path a -> String -> Path a
- splitExtension :: Path a -> (Path a, String)
- takeExtension :: Path a -> String
- data Unrooted
- (</>) :: Path a -> Path Unrooted -> Path a
- rootPath :: Path Unrooted -> Path root
- unrootPath :: Path root -> Path Unrooted
- toUnrootedFilePath :: Path Unrooted -> FilePath
- fromUnrootedFilePath :: FilePath -> Path Unrooted
- fragment :: String -> Path Unrooted
- joinFragments :: [String] -> Path Unrooted
- splitFragments :: Path Unrooted -> [String]
- isPathPrefixOf :: Path Unrooted -> Path Unrooted -> Bool
- data Relative
- data Absolute
- data HomeDir
- class FsRoot root where
- toAbsoluteFilePath :: Path root -> IO FilePath
- data FsPath = FsRoot root => FsPath (Path root)
- toFilePath :: Path Absolute -> FilePath
- fromFilePath :: FilePath -> FsPath
- makeAbsolute :: FsPath -> IO (Path Absolute)
- fromAbsoluteFilePath :: FilePath -> Path Absolute
- withFile :: FsRoot root => Path root -> IOMode -> (Handle -> IO r) -> IO r
- openTempFile' :: FsRoot root => Path root -> String -> IO (Path Absolute, Handle)
- readLazyByteString :: FsRoot root => Path root -> IO ByteString
- readStrictByteString :: FsRoot root => Path root -> IO ByteString
- writeLazyByteString :: FsRoot root => Path root -> ByteString -> IO ()
- writeStrictByteString :: FsRoot root => Path root -> ByteString -> IO ()
- copyFile :: (FsRoot root, FsRoot root') => Path root -> Path root' -> IO ()
- createDirectory :: FsRoot root => Path root -> IO ()
- createDirectoryIfMissing :: FsRoot root => Bool -> Path root -> IO ()
- removeDirectory :: FsRoot root => Path root -> IO ()
- doesFileExist :: FsRoot root => Path root -> IO Bool
- doesDirectoryExist :: FsRoot root => Path root -> IO Bool
- getModificationTime :: FsRoot root => Path root -> IO UTCTime
- removeFile :: FsRoot root => Path root -> IO ()
- getTemporaryDirectory :: IO (Path Absolute)
- getDirectoryContents :: FsRoot root => Path root -> IO [Path Unrooted]
- getRecursiveContents :: FsRoot root => Path root -> IO [Path Unrooted]
- renameFile :: (FsRoot root, FsRoot root') => Path root -> Path root' -> IO ()
- getCurrentDirectory :: IO (Path Absolute)
- data Tar
- tarIndexLookup :: TarIndex -> Path Tar -> Maybe TarIndexEntry
- tarAppend :: (FsRoot root, FsRoot root') => Path root -> Path root' -> [Path Tar] -> IO ()
- data Web
- toURIPath :: FilePath -> Path Web
- fromURIPath :: Path Web -> FilePath
- uriPath :: URI -> Path Web
- modifyUriPath :: URI -> (Path Web -> Path Web) -> URI
- data IOMode
- data BufferMode
- data Handle
- data SeekMode
- hSetBuffering :: Handle -> BufferMode -> IO ()
- hClose :: Handle -> IO ()
- hFileSize :: Handle -> IO Integer
- hSeek :: Handle -> SeekMode -> Integer -> IO ()
Paths
Paths
A Path is simply a FilePath with a type-level tag indicating where this
path is rooted (relative to the current directory, absolute path, relative to
a web domain, whatever). Most operations on Path are just lifted versions
of the operations on the underlying FilePath. The tag however allows us to
give a lot of operations a more meaningful type. For instance, it does not
make sense to append two absolute paths together; instead, we can only append
an unrooted path to another path. It also means we avoid bugs where we use
one kind of path where we expect another.
Instances
| Monad m => FromObjectKey m (Path root) Source # | |
Defined in Hackage.Security.Util.JSON | |
| Monad m => ToObjectKey m (Path root) Source # | |
Defined in Hackage.Security.Util.JSON Methods toObjectKey :: Path root -> m String Source # | |
| Show (Path a) Source # | |
| Eq (Path a) Source # | |
| Ord (Path a) Source # | |
| Pretty (Path CacheRoot) Source # | |
| Pretty (Path IndexRoot) Source # | |
| Pretty (Path RepoRoot) Source # | |
| Pretty (Path Absolute) Source # | |
| Pretty (Path HomeDir) Source # | |
| Pretty (Path Relative) Source # | |
| Pretty (Path Tar) Source # | |
| Pretty (Path Unrooted) Source # | |
castRoot :: Path root -> Path root' Source #
Reinterpret the root of a path
This literally just changes the type-level tag; use with caution!
FilePath-like operations on paths with arbitrary roots
takeDirectory :: Path a -> Path a Source #
takeFileName :: Path a -> String Source #
takeExtension :: Path a -> String Source #
Unrooted paths
Type-level tag for unrooted paths
Unrooted paths need a root before they can be interpreted.
rootPath :: Path Unrooted -> Path root Source #
Reinterpret an unrooted path
This is an alias for castRoot; see comments there.
unrootPath :: Path root -> Path Unrooted Source #
Forget a path's root
This is an alias for castRoot; see comments there.
toUnrootedFilePath :: Path Unrooted -> FilePath Source #
Convert a relative/unrooted Path to a FilePath (using POSIX style directory separators).
See also toAbsoluteFilePath
fromUnrootedFilePath :: FilePath -> Path Unrooted Source #
Convert from a relative/unrooted FilePath (using POSIX style directory separators).
File-system paths
class FsRoot root where Source #
A file system root can be interpreted as an (absolute) FilePath
Methods
toAbsoluteFilePath :: Path root -> IO FilePath Source #
Convert a Path to an absolute FilePath (using native style directory separators).
Instances
| FsRoot Absolute Source # | |
Defined in Hackage.Security.Util.Path | |
| FsRoot HomeDir Source # | |
Defined in Hackage.Security.Util.Path | |
| FsRoot Relative Source # | |
Defined in Hackage.Security.Util.Path | |
Abstract over a file system root
see fromFilePath
Conversions
fromFilePath :: FilePath -> FsPath Source #
Wrappers around System.IO
withFile :: FsRoot root => Path root -> IOMode -> (Handle -> IO r) -> IO r Source #
Wrapper around withFile
openTempFile' :: FsRoot root => Path root -> String -> IO (Path Absolute, Handle) Source #
Wrapper around openBinaryTempFileWithDefaultPermissions
NOTE: The caller is responsible for cleaning up the temporary file.
Wrappers around Data.ByteString
readLazyByteString :: FsRoot root => Path root -> IO ByteString Source #
readStrictByteString :: FsRoot root => Path root -> IO ByteString Source #
writeLazyByteString :: FsRoot root => Path root -> ByteString -> IO () Source #
writeStrictByteString :: FsRoot root => Path root -> ByteString -> IO () Source #
Wrappers around System.Directory
getDirectoryContents :: FsRoot root => Path root -> IO [Path Unrooted] Source #
Return the immediate children of a directory
Filters out "." and "..".
getRecursiveContents :: FsRoot root => Path root -> IO [Path Unrooted] Source #
Recursive traverse a directory structure
Returns a set of paths relative to the directory specified. The list is lazily constructed, so that directories are only read when required. (This is also essential to ensure that this function does not build the entire result in memory before returning, potentially running out of heap.)
Wrappers around Codec.Archive.Tar
Wrappers around Network.URI
Re-exports
See openFile
Constructors
| ReadMode | |
| WriteMode | |
| AppendMode | |
| ReadWriteMode |
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
hFlushis issued, or the handle is closed. - block-buffering: the entire buffer is written out whenever it
overflows, a
hFlushis 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
hLookAheadoperation 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 |
Instances
| Read BufferMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Handle.Types Methods readsPrec :: Int -> ReadS BufferMode # readList :: ReadS [BufferMode] # readPrec :: ReadPrec BufferMode # readListPrec :: ReadPrec [BufferMode] # | |
| Show BufferMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Handle.Types Methods showsPrec :: Int -> BufferMode -> ShowS # show :: BufferMode -> String # showList :: [BufferMode] -> ShowS # | |
| Eq BufferMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Handle.Types | |
| Ord BufferMode | Since: base-4.2.0.0 |
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 # | |
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
A mode that determines the effect of hSeek hdl mode i.
Constructors
| AbsoluteSeek | the position of |
| RelativeSeek | the position of |
| SeekFromEnd | the position of |
Instances
| Enum SeekMode | Since: base-4.2.0.0 |
| Ix SeekMode | Since: base-4.2.0.0 |
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 # | |
| Read SeekMode | Since: base-4.2.0.0 |
| Show SeekMode | Since: base-4.2.0.0 |
| Eq SeekMode | Since: base-4.2.0.0 |
| Ord SeekMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Device | |
hSetBuffering :: Handle -> BufferMode -> IO () #
Computation hSetBuffering hdl mode sets the mode of buffering for
handle hdl on subsequent reads and writes.
If the buffer mode is changed from BlockBuffering or
LineBuffering to NoBuffering, then
- if
hdlis writable, the buffer is flushed as forhFlush; - if
hdlis not writable, the contents of the buffer are discarded.
This operation may fail with:
isPermissionErrorif the handle has already been used for reading or writing and the implementation does not allow the buffering mode to be changed.
Computation hClose hdl makes handle hdl closed. Before the
computation finishes, if hdl is writable its buffer is flushed as
for hFlush.
Performing hClose on a handle that has already been closed has no effect;
doing so is not an error. All other operations on a closed handle will fail.
If hClose fails for any reason, any further operations (apart from
hClose) on the handle will still fail as if hdl had been successfully
closed.
hClose is an interruptible operation in the sense described in
Control.Exception. If hClose is interrupted by an asynchronous
exception in the process of flushing its buffers, then the I/O device
(e.g., file) will be closed anyway.
hFileSize :: Handle -> IO Integer #
For a handle hdl which attached to a physical file,
hFileSize hdl returns the size of that file in 8-bit bytes.
hSeek :: Handle -> SeekMode -> Integer -> IO () #
Computation hSeek hdl mode i sets the position of handle
hdl depending on mode.
The offset i is given in terms of 8-bit bytes.
If hdl is block- or line-buffered, then seeking to a position which is not
in the current buffer will first cause any items in the output buffer to be
written to the device, and then cause the input buffer to be discarded.
Some handles may not be seekable (see hIsSeekable), or only support a
subset of the possible positioning operations (for instance, it may only
be possible to seek to the end of a tape, or to a positive offset from
the beginning or current position).
It is not possible to set a negative I/O position, or for
a physical file, an I/O position beyond the current end-of-file.
This operation may fail with:
isIllegalOperationErrorif the Handle is not seekable, or does not support the requested seek mode.isPermissionErrorif a system resource limit would be exceeded.