-{-# OPTIONS -fno-implicit-prelude -#include "HsBase.h" #-}
-
-#undef DEBUG_DUMP
-#undef DEBUG
-
+{-# OPTIONS_HADDOCK hide #-}
-----------------------------------------------------------------------------
-- |
-- Module : GHC.Handle
-- Stability : internal
-- Portability : non-portable
--
--- This module defines the basic operations on I\/O \"handles\".
+-- Backwards-compatibility interface
--
-----------------------------------------------------------------------------
-module GHC.Handle (
+-- #hide
+
+module GHC.Handle {-# DEPRECATED "use GHC.IO.Handle instead" #-} (
withHandle, withHandle', withHandle_,
wantWritableHandle, wantReadableHandle, wantSeekableHandle,
-
- newEmptyBuffer, allocateBuffer, readCharFromBuffer, writeCharIntoBuffer,
- flushWriteBufferOnly, flushWriteBuffer, flushReadBuffer, fillReadBuffer,
- read_off, read_off_ba,
- write_off, write_off_ba, unlockFile,
+
+-- newEmptyBuffer, allocateBuffer, readCharFromBuffer, writeCharIntoBuffer,
+-- flushWriteBufferOnly, flushWriteBuffer,
+-- flushReadBuffer,
+-- fillReadBuffer, fillReadBufferWithoutBlocking,
+-- readRawBuffer, readRawBufferPtr,
+-- readRawBufferNoBlock, readRawBufferPtrNoBlock,
+-- writeRawBuffer, writeRawBufferPtr,
ioe_closedHandle, ioe_EOF, ioe_notReadable, ioe_notWritable,
stdin, stdout, stderr,
- IOMode(..), IOModeEx(..), openFile, openFileEx, openFd, fdToHandle,
- hFileSize, hIsEOF, isEOF, hLookAhead, hSetBuffering, hSetBinaryMode,
+ IOMode(..), openFile, openBinaryFile,
+-- fdToHandle_stat,
+ fdToHandle, fdToHandle',
+ hFileSize, hSetFileSize, hIsEOF, isEOF, hLookAhead, hLookAhead_,
+ hSetBuffering, hSetBinaryMode,
hFlush, hDuplicate, hDuplicateTo,
hClose, hClose_help,
- HandlePosn(..), hGetPosn, hSetPosn,
+ HandlePosition, HandlePosn(..), hGetPosn, hSetPosn,
SeekMode(..), hSeek, hTell,
hIsOpen, hIsClosed, hIsReadable, hIsWritable, hGetBuffering, hIsSeekable,
hSetEcho, hGetEcho, hIsTerminalDevice,
-#ifdef DEBUG_DUMP
- puts,
-#endif
+ hShow,
) where
-#include "config.h"
-
-import Control.Monad
-import Data.Bits
-import Data.Maybe
-import Foreign
-import Foreign.C
-import System.IO.Error
-
-import GHC.Posix
-import GHC.Real
-
-import GHC.Arr
-import GHC.Base
-import GHC.Read ( Read )
-import GHC.List
-import GHC.IOBase
-import GHC.Exception
-import GHC.Enum
-import GHC.Num ( Integer(..), Num(..) )
-import GHC.Show
-import GHC.Real ( toInteger )
-
-import GHC.Conc
-
--- -----------------------------------------------------------------------------
--- TODO:
-
--- hWaitForInput blocks (should use a timeout)
-
--- unbuffered hGetLine is a bit dodgy
-
--- hSetBuffering: can't change buffering on a stream,
--- when the read buffer is non-empty? (no way to flush the buffer)
-
--- ---------------------------------------------------------------------------
--- Are files opened by default in text or binary mode, if the user doesn't
--- specify?
-
-dEFAULT_OPEN_IN_BINARY_MODE = False :: Bool
-
--- ---------------------------------------------------------------------------
--- Creating a new handle
-
-newFileHandle :: (MVar Handle__ -> IO ()) -> Handle__ -> IO Handle
-newFileHandle finalizer hc = do
- m <- newMVar hc
- addMVarFinalizer m (finalizer m)
- return (FileHandle m)
-
--- ---------------------------------------------------------------------------
--- Working with Handles
-
-{-
-In the concurrent world, handles are locked during use. This is done
-by wrapping an MVar around the handle which acts as a mutex over
-operations on the handle.
-
-To avoid races, we use the following bracketing operations. The idea
-is to obtain the lock, do some operation and replace the lock again,
-whether the operation succeeded or failed. We also want to handle the
-case where the thread receives an exception while processing the IO
-operation: in these cases we also want to relinquish the lock.
-
-There are three versions of @withHandle@: corresponding to the three
-possible combinations of:
-
- - the operation may side-effect the handle
- - the operation may return a result
-
-If the operation generates an error or an exception is raised, the
-original handle is always replaced [ this is the case at the moment,
-but we might want to revisit this in the future --SDM ].
--}
-
-{-# INLINE withHandle #-}
-withHandle :: String -> Handle -> (Handle__ -> IO (Handle__,a)) -> IO a
-withHandle fun h@(FileHandle m) act = withHandle' fun h m act
-withHandle fun h@(DuplexHandle m _) act = withHandle' fun h m act
-
-withHandle' :: String -> Handle -> MVar Handle__
- -> (Handle__ -> IO (Handle__,a)) -> IO a
-withHandle' fun h m act =
- block $ do
- h_ <- takeMVar m
- checkBufferInvariants h_
- (h',v) <- catchException (act h_)
- (\ err -> putMVar m h_ >>
- case err of
- IOException ex -> ioError (augmentIOError ex fun h h_)
- _ -> throw err)
- checkBufferInvariants h'
- putMVar m h'
- return v
-
-{-# INLINE withHandle_ #-}
-withHandle_ :: String -> Handle -> (Handle__ -> IO a) -> IO a
-withHandle_ fun h@(FileHandle m) act = withHandle_' fun h m act
-withHandle_ fun h@(DuplexHandle m _) act = withHandle_' fun h m act
-
-withHandle_' fun h m act =
- block $ do
- h_ <- takeMVar m
- checkBufferInvariants h_
- v <- catchException (act h_)
- (\ err -> putMVar m h_ >>
- case err of
- IOException ex -> ioError (augmentIOError ex fun h h_)
- _ -> throw err)
- checkBufferInvariants h_
- putMVar m h_
- return v
-
-withAllHandles__ :: String -> Handle -> (Handle__ -> IO Handle__) -> IO ()
-withAllHandles__ fun h@(FileHandle m) act = withHandle__' fun h m act
-withAllHandles__ fun h@(DuplexHandle r w) act = do
- withHandle__' fun h r act
- withHandle__' fun h w act
-
-withHandle__' fun h m act =
- block $ do
- h_ <- takeMVar m
- checkBufferInvariants h_
- h' <- catchException (act h_)
- (\ err -> putMVar m h_ >>
- case err of
- IOException ex -> ioError (augmentIOError ex fun h h_)
- _ -> throw err)
- checkBufferInvariants h'
- putMVar m h'
- return ()
-
-augmentIOError (IOError _ iot _ str fp) fun h h_
- = IOError (Just h) iot fun str filepath
- where filepath | Just _ <- fp = fp
- | otherwise = Just (haFilePath h_)
-
--- ---------------------------------------------------------------------------
--- Wrapper for write operations.
-
-wantWritableHandle :: String -> Handle -> (Handle__ -> IO a) -> IO a
-wantWritableHandle fun h@(FileHandle m) act
- = wantWritableHandle' fun h m act
-wantWritableHandle fun h@(DuplexHandle _ m) act
- = wantWritableHandle' fun h m act
- -- ToDo: in the Duplex case, we don't need to checkWritableHandle
-
-wantWritableHandle'
- :: String -> Handle -> MVar Handle__
- -> (Handle__ -> IO a) -> IO a
-wantWritableHandle' fun h m act
- = withHandle_' fun h m (checkWritableHandle act)
-
-checkWritableHandle act handle_
- = case haType handle_ of
- ClosedHandle -> ioe_closedHandle
- SemiClosedHandle -> ioe_closedHandle
- ReadHandle -> ioe_notWritable
- ReadWriteHandle -> do
- let ref = haBuffer handle_
- buf <- readIORef ref
- new_buf <-
- if not (bufferIsWritable buf)
- then do b <- flushReadBuffer (haFD handle_) buf
- return b{ bufState=WriteBuffer }
- else return buf
- writeIORef ref new_buf
- act handle_
- _other -> act handle_
-
--- ---------------------------------------------------------------------------
--- Wrapper for read operations.
-
-wantReadableHandle :: String -> Handle -> (Handle__ -> IO a) -> IO a
-wantReadableHandle fun h@(FileHandle m) act
- = wantReadableHandle' fun h m act
-wantReadableHandle fun h@(DuplexHandle m _) act
- = wantReadableHandle' fun h m act
- -- ToDo: in the Duplex case, we don't need to checkReadableHandle
-
-wantReadableHandle'
- :: String -> Handle -> MVar Handle__
- -> (Handle__ -> IO a) -> IO a
-wantReadableHandle' fun h m act
- = withHandle_' fun h m (checkReadableHandle act)
-
-checkReadableHandle act handle_ =
- case haType handle_ of
- ClosedHandle -> ioe_closedHandle
- SemiClosedHandle -> ioe_closedHandle
- AppendHandle -> ioe_notReadable
- WriteHandle -> ioe_notReadable
- ReadWriteHandle -> do
- let ref = haBuffer handle_
- buf <- readIORef ref
- when (bufferIsWritable buf) $ do
- new_buf <- flushWriteBuffer (haFD handle_) (haIsStream handle_) buf
- writeIORef ref new_buf{ bufState=ReadBuffer }
- act handle_
- _other -> act handle_
-
--- ---------------------------------------------------------------------------
--- Wrapper for seek operations.
-
-wantSeekableHandle :: String -> Handle -> (Handle__ -> IO a) -> IO a
-wantSeekableHandle fun h@(DuplexHandle _ _) _act =
- ioException (IOError (Just h) IllegalOperation fun
- "handle is not seekable" Nothing)
-wantSeekableHandle fun h@(FileHandle m) act =
- withHandle_' fun h m (checkSeekableHandle act)
-
-checkSeekableHandle act handle_ =
- case haType handle_ of
- ClosedHandle -> ioe_closedHandle
- SemiClosedHandle -> ioe_closedHandle
- AppendHandle -> ioe_notSeekable
- _ | haIsBin handle_ || tEXT_MODE_SEEK_ALLOWED -> act handle_
- | otherwise -> ioe_notSeekable_notBin
-
--- -----------------------------------------------------------------------------
--- Handy IOErrors
-
-ioe_closedHandle, ioe_EOF,
- ioe_notReadable, ioe_notWritable,
- ioe_notSeekable, ioe_notSeekable_notBin :: IO a
-
-ioe_closedHandle = ioException
- (IOError Nothing IllegalOperation ""
- "handle is closed" Nothing)
-ioe_EOF = ioException
- (IOError Nothing EOF "" "" Nothing)
-ioe_notReadable = ioException
- (IOError Nothing IllegalOperation ""
- "handle is not open for reading" Nothing)
-ioe_notWritable = ioException
- (IOError Nothing IllegalOperation ""
- "handle is not open for writing" Nothing)
-ioe_notSeekable = ioException
- (IOError Nothing IllegalOperation ""
- "handle is not seekable" Nothing)
-ioe_notSeekable_notBin = ioException
- (IOError Nothing IllegalOperation ""
- "seek operations on text-mode handles are not allowed on this platform"
- Nothing)
-
-ioe_bufsiz :: Int -> IO a
-ioe_bufsiz n = ioException
- (IOError Nothing InvalidArgument "hSetBuffering"
- ("illegal buffer size " ++ showsPrec 9 n []) Nothing)
- -- 9 => should be parens'ified.
-
--- -----------------------------------------------------------------------------
--- Handle Finalizers
-
--- For a duplex handle, we arrange that the read side points to the write side
--- (and hence keeps it alive if the read side is alive). This is done by
--- having the haOtherSide field of the read side point to the read side.
--- The finalizer is then placed on the write side, and the handle only gets
--- finalized once, when both sides are no longer required.
-
-stdHandleFinalizer :: MVar Handle__ -> IO ()
-stdHandleFinalizer m = do
- h_ <- takeMVar m
- flushWriteBufferOnly h_
-
-handleFinalizer :: MVar Handle__ -> IO ()
-handleFinalizer m = do
- h_ <- takeMVar m
- let
- -- hClose puts both the fd and the handle's type
- -- into a closed state, so it's a bit excessive
- -- to test for both here, but caution sometimes
- -- pays off..
- alreadyClosed =
- case haType h_ of { ClosedHandle{} -> True; _ -> False }
- fd = fromIntegral (haFD h_)
-
- when (not alreadyClosed && fd /= -1) $ do
- flushWriteBufferOnly h_
- unlockFile fd
-#ifdef mingw32_TARGET_OS
- (closeFd (haIsStream h_) fd >> return ())
-#else
- (c_close fd >> return ())
-#endif
-
--- ---------------------------------------------------------------------------
--- Grimy buffer operations
-
-#ifdef DEBUG
-checkBufferInvariants h_ = do
- let ref = haBuffer h_
- Buffer{ bufWPtr=w, bufRPtr=r, bufSize=size, bufState=state } <- readIORef ref
- if not (
- size > 0
- && r <= w
- && w <= size
- && ( r /= w || (r == 0 && w == 0) )
- && ( state /= WriteBuffer || r == 0 )
- && ( state /= WriteBuffer || w < size ) -- write buffer is never full
- )
- then error "buffer invariant violation"
- else return ()
-#else
-checkBufferInvariants h_ = return ()
-#endif
-
-newEmptyBuffer :: RawBuffer -> BufferState -> Int -> Buffer
-newEmptyBuffer b state size
- = Buffer{ bufBuf=b, bufRPtr=0, bufWPtr=0, bufSize=size, bufState=state }
-
-allocateBuffer :: Int -> BufferState -> IO Buffer
-allocateBuffer sz@(I# size) state = IO $ \s ->
- case newByteArray# size s of { (# s, b #) ->
- (# s, newEmptyBuffer b state sz #) }
-
-writeCharIntoBuffer :: RawBuffer -> Int -> Char -> IO Int
-writeCharIntoBuffer slab (I# off) (C# c)
- = IO $ \s -> case writeCharArray# slab off c s of
- s -> (# s, I# (off +# 1#) #)
-
-readCharFromBuffer :: RawBuffer -> Int -> IO (Char, Int)
-readCharFromBuffer slab (I# off)
- = IO $ \s -> case readCharArray# slab off s of
- (# s, c #) -> (# s, (C# c, I# (off +# 1#)) #)
-
-getBuffer :: FD -> BufferState -> IO (IORef Buffer, BufferMode)
-getBuffer fd state = do
- buffer <- allocateBuffer dEFAULT_BUFFER_SIZE state
- ioref <- newIORef buffer
- is_tty <- fdIsTTY fd
-
- let buffer_mode
- | is_tty = LineBuffering
- | otherwise = BlockBuffering Nothing
-
- return (ioref, buffer_mode)
-
-mkUnBuffer :: IO (IORef Buffer)
-mkUnBuffer = do
- buffer <- allocateBuffer 1 ReadBuffer
- newIORef buffer
-
--- flushWriteBufferOnly flushes the buffer iff it contains pending write data.
-flushWriteBufferOnly :: Handle__ -> IO ()
-flushWriteBufferOnly h_ = do
- let fd = haFD h_
- ref = haBuffer h_
- buf <- readIORef ref
- new_buf <- if bufferIsWritable buf
- then flushWriteBuffer fd (haIsStream h_) buf
- else return buf
- writeIORef ref new_buf
-
--- flushBuffer syncs the file with the buffer, including moving the
--- file pointer backwards in the case of a read buffer.
-flushBuffer :: Handle__ -> IO ()
-flushBuffer h_ = do
- let ref = haBuffer h_
- buf <- readIORef ref
-
- flushed_buf <-
- case bufState buf of
- ReadBuffer -> flushReadBuffer (haFD h_) buf
- WriteBuffer -> flushWriteBuffer (haFD h_) (haIsStream h_) buf
-
- writeIORef ref flushed_buf
-
--- When flushing a read buffer, we seek backwards by the number of
--- characters in the buffer. The file descriptor must therefore be
--- seekable: attempting to flush the read buffer on an unseekable
--- handle is not allowed.
-
-flushReadBuffer :: FD -> Buffer -> IO Buffer
-flushReadBuffer fd buf
- | bufferEmpty buf = return buf
- | otherwise = do
- let off = negate (bufWPtr buf - bufRPtr buf)
-# ifdef DEBUG_DUMP
- puts ("flushReadBuffer: new file offset = " ++ show off ++ "\n")
-# endif
- throwErrnoIfMinus1Retry "flushReadBuffer"
- (c_lseek (fromIntegral fd) (fromIntegral off) sEEK_CUR)
- return buf{ bufWPtr=0, bufRPtr=0 }
-
-flushWriteBuffer :: FD -> Bool -> Buffer -> IO Buffer
-flushWriteBuffer fd is_stream buf@Buffer{ bufBuf=b, bufRPtr=r, bufWPtr=w } = do
- let bytes = w - r
-#ifdef DEBUG_DUMP
- puts ("flushWriteBuffer, fd=" ++ show fd ++ ", bytes=" ++ show bytes ++ "\n")
-#endif
- if bytes == 0
- then return (buf{ bufRPtr=0, bufWPtr=0 })
- else do
- res <- throwErrnoIfMinus1RetryMayBlock "flushWriteBuffer"
- (write_off_ba (fromIntegral fd) is_stream b (fromIntegral r)
- (fromIntegral bytes))
- (threadWaitWrite fd)
- let res' = fromIntegral res
- if res' < bytes
- then flushWriteBuffer fd is_stream (buf{ bufRPtr = r + res' })
- else return buf{ bufRPtr=0, bufWPtr=0 }
-
-foreign import ccall unsafe "__hscore_PrelHandle_write"
- write_off_ba :: CInt -> Bool -> RawBuffer -> Int -> CInt -> IO CInt
-
-foreign import ccall unsafe "__hscore_PrelHandle_write"
- write_off :: CInt -> Bool -> Ptr CChar -> Int -> CInt -> IO CInt
-
-fillReadBuffer :: FD -> Bool -> Bool -> Buffer -> IO Buffer
-fillReadBuffer fd is_line is_stream
- buf@Buffer{ bufBuf=b, bufRPtr=r, bufWPtr=w, bufSize=size } =
- -- buffer better be empty:
- assert (r == 0 && w == 0) $ do
- fillReadBufferLoop fd is_line is_stream buf b w size
-
--- For a line buffer, we just get the first chunk of data to arrive,
--- and don't wait for the whole buffer to be full (but we *do* wait
--- until some data arrives). This isn't really line buffering, but it
--- appears to be what GHC has done for a long time, and I suspect it
--- is more useful than line buffering in most cases.
-
-fillReadBufferLoop fd is_line is_stream buf b w size = do
- let bytes = size - w
- if bytes == 0 -- buffer full?
- then return buf{ bufRPtr=0, bufWPtr=w }
- else do
-#ifdef DEBUG_DUMP
- puts ("fillReadBufferLoop: bytes = " ++ show bytes ++ "\n")
-#endif
- res <- throwErrnoIfMinus1RetryMayBlock "fillReadBuffer"
- (read_off_ba fd is_stream b (fromIntegral w) (fromIntegral bytes))
- (threadWaitRead fd)
- let res' = fromIntegral res
-#ifdef DEBUG_DUMP
- puts ("fillReadBufferLoop: res' = " ++ show res' ++ "\n")
-#endif
- if res' == 0
- then if w == 0
- then ioe_EOF
- else return buf{ bufRPtr=0, bufWPtr=w }
- else if res' < bytes && not is_line
- then fillReadBufferLoop fd is_line is_stream buf b (w+res') size
- else return buf{ bufRPtr=0, bufWPtr=w+res' }
-
-foreign import ccall unsafe "__hscore_PrelHandle_read"
- read_off_ba :: FD -> Bool -> RawBuffer -> Int -> CInt -> IO CInt
-
-foreign import ccall unsafe "__hscore_PrelHandle_read"
- read_off :: FD -> Bool -> Ptr CChar -> Int -> CInt -> IO CInt
-
--- ---------------------------------------------------------------------------
--- Standard Handles
-
--- Three handles are allocated during program initialisation. The first
--- two manage input or output from the Haskell program's standard input
--- or output channel respectively. The third manages output to the
--- standard error channel. These handles are initially open.
-
-fd_stdin = 0 :: FD
-fd_stdout = 1 :: FD
-fd_stderr = 2 :: FD
-
-stdin :: Handle
-stdin = unsafePerformIO $ do
- -- ToDo: acquire lock
- setNonBlockingFD fd_stdin
- (buf, bmode) <- getBuffer fd_stdin ReadBuffer
- mkStdHandle fd_stdin "<stdin>" ReadHandle buf bmode
-
-stdout :: Handle
-stdout = unsafePerformIO $ do
- -- ToDo: acquire lock
- -- We don't set non-blocking mode on stdout or sterr, because
- -- some shells don't recover properly.
- -- setNonBlockingFD fd_stdout
- (buf, bmode) <- getBuffer fd_stdout WriteBuffer
- mkStdHandle fd_stdout "<stdout>" WriteHandle buf bmode
-
-stderr :: Handle
-stderr = unsafePerformIO $ do
- -- ToDo: acquire lock
- -- We don't set non-blocking mode on stdout or sterr, because
- -- some shells don't recover properly.
- -- setNonBlockingFD fd_stderr
- buf <- mkUnBuffer
- mkStdHandle fd_stderr "<stderr>" WriteHandle buf NoBuffering
-
--- ---------------------------------------------------------------------------
--- Opening and Closing Files
-
-{-
-Computation `openFile file mode' allocates and returns a new, open
-handle to manage the file `file'. It manages input if `mode'
-is `ReadMode', output if `mode' is `WriteMode' or `AppendMode',
-and both input and output if mode is `ReadWriteMode'.
-
-If the file does not exist and it is opened for output, it should be
-created as a new file. If `mode' is `WriteMode' and the file
-already exists, then it should be truncated to zero length. The
-handle is positioned at the end of the file if `mode' is
-`AppendMode', and otherwise at the beginning (in which case its
-internal position is 0).
-
-Implementations should enforce, locally to the Haskell process,
-multiple-reader single-writer locking on files, which is to say that
-there may either be many handles on the same file which manage input,
-or just one handle on the file which manages output. If any open or
-semi-closed handle is managing a file for output, no new handle can be
-allocated for that file. If any open or semi-closed handle is
-managing a file for input, new handles can only be allocated if they
-do not manage output.
-
-Two files are the same if they have the same absolute name. An
-implementation is free to impose stricter conditions.
--}
-
-data IOModeEx
- = BinaryMode IOMode
- | TextMode IOMode
- deriving (Eq, Read, Show)
-
-addFilePathToIOError fun fp (IOError h iot _ str _)
- = IOError h iot fun str (Just fp)
-
-openFile :: FilePath -> IOMode -> IO Handle
-openFile fp im =
- catch
- (openFile' fp (if dEFAULT_OPEN_IN_BINARY_MODE
- then BinaryMode im
- else TextMode im))
- (\e -> ioError (addFilePathToIOError "openFile" fp e))
-
-openFileEx :: FilePath -> IOModeEx -> IO Handle
-openFileEx fp m =
- catch
- (openFile' fp m)
- (\e -> ioError (addFilePathToIOError "openFileEx" fp e))
-
-
-openFile' filepath ex_mode =
- withCString filepath $ \ f ->
-
- let
- (mode, binary) =
- case ex_mode of
- BinaryMode bmo -> (bmo, True)
- TextMode tmo -> (tmo, False)
-
- oflags1 = case mode of
- ReadMode -> read_flags
- WriteMode -> write_flags
- ReadWriteMode -> rw_flags
- AppendMode -> append_flags
-
- truncate | WriteMode <- mode = True
- | otherwise = False
-
- binary_flags
- | binary = o_BINARY
- | otherwise = 0
-
- oflags = oflags1 .|. binary_flags
- in do
-
- -- the old implementation had a complicated series of three opens,
- -- which is perhaps because we have to be careful not to open
- -- directories. However, the man pages I've read say that open()
- -- always returns EISDIR if the file is a directory and was opened
- -- for writing, so I think we're ok with a single open() here...
- fd <- fromIntegral `liftM`
- throwErrnoIfMinus1Retry "openFile"
- (c_open f (fromIntegral oflags) 0o666)
-
- openFd fd Nothing filepath mode binary truncate
- -- ASSERT: if we just created the file, then openFd won't fail
- -- (so we don't need to worry about removing the newly created file
- -- in the event of an error).
-
-
-std_flags = o_NONBLOCK .|. o_NOCTTY
-output_flags = std_flags .|. o_CREAT
-read_flags = std_flags .|. o_RDONLY
-write_flags = output_flags .|. o_WRONLY
-rw_flags = output_flags .|. o_RDWR
-append_flags = write_flags .|. o_APPEND
-
--- ---------------------------------------------------------------------------
--- openFd
-
-openFd :: FD -> Maybe FDType -> FilePath -> IOMode -> Bool -> Bool -> IO Handle
-openFd fd mb_fd_type filepath mode binary truncate = do
- -- turn on non-blocking mode
- setNonBlockingFD fd
-
- let (ha_type, write) =
- case mode of
- ReadMode -> ( ReadHandle, False )
- WriteMode -> ( WriteHandle, True )
- ReadWriteMode -> ( ReadWriteHandle, True )
- AppendMode -> ( AppendHandle, True )
-
- -- open() won't tell us if it was a directory if we only opened for
- -- reading, so check again.
- fd_type <-
- case mb_fd_type of
- Just x -> return x
- Nothing -> fdType fd
- let is_stream = fd_type == Stream
- case fd_type of
- Directory ->
- ioException (IOError Nothing InappropriateType "openFile"
- "is a directory" Nothing)
-
- Stream
- | ReadWriteHandle <- ha_type -> mkDuplexHandle fd is_stream filepath binary
- | otherwise -> mkFileHandle fd is_stream filepath ha_type binary
-
- -- regular files need to be locked
- RegularFile -> do
- r <- lockFile (fromIntegral fd) (fromBool write) 1{-exclusive-}
- when (r == -1) $
- ioException (IOError Nothing ResourceBusy "openFile"
- "file is locked" Nothing)
-
- -- truncate the file if necessary
- when truncate (fileTruncate filepath)
-
- mkFileHandle fd is_stream filepath ha_type binary
-
-
-fdToHandle :: FD -> IO Handle
-fdToHandle fd = do
- mode <- fdGetMode fd
- let fd_str = "<file descriptor: " ++ show fd ++ ">"
- openFd fd Nothing fd_str mode True{-bin mode-} False{-no truncate-}
-
-foreign import ccall unsafe "lockFile"
- lockFile :: CInt -> CInt -> CInt -> IO CInt
-
-foreign import ccall unsafe "unlockFile"
- unlockFile :: CInt -> IO CInt
-
-mkStdHandle :: FD -> FilePath -> HandleType -> IORef Buffer -> BufferMode
- -> IO Handle
-mkStdHandle fd filepath ha_type buf bmode = do
- spares <- newIORef BufferListNil
- newFileHandle stdHandleFinalizer
- (Handle__ { haFD = fd,
- haType = ha_type,
- haIsBin = dEFAULT_OPEN_IN_BINARY_MODE,
- haIsStream = False,
- haBufferMode = bmode,
- haFilePath = filepath,
- haBuffer = buf,
- haBuffers = spares,
- haOtherSide = Nothing
- })
-
-mkFileHandle :: FD -> Bool -> FilePath -> HandleType -> Bool -> IO Handle
-mkFileHandle fd is_stream filepath ha_type binary = do
- (buf, bmode) <- getBuffer fd (initBufferState ha_type)
- spares <- newIORef BufferListNil
- newFileHandle handleFinalizer
- (Handle__ { haFD = fd,
- haType = ha_type,
- haIsBin = binary,
- haIsStream = is_stream,
- haBufferMode = bmode,
- haFilePath = filepath,
- haBuffer = buf,
- haBuffers = spares,
- haOtherSide = Nothing
- })
-
-mkDuplexHandle :: FD -> Bool -> FilePath -> Bool -> IO Handle
-mkDuplexHandle fd is_stream filepath binary = do
- (w_buf, w_bmode) <- getBuffer fd WriteBuffer
- w_spares <- newIORef BufferListNil
- let w_handle_ =
- Handle__ { haFD = fd,
- haType = WriteHandle,
- haIsBin = binary,
- haIsStream = is_stream,
- haBufferMode = w_bmode,
- haFilePath = filepath,
- haBuffer = w_buf,
- haBuffers = w_spares,
- haOtherSide = Nothing
- }
- write_side <- newMVar w_handle_
-
- (r_buf, r_bmode) <- getBuffer fd ReadBuffer
- r_spares <- newIORef BufferListNil
- let r_handle_ =
- Handle__ { haFD = fd,
- haType = ReadHandle,
- haIsBin = binary,
- haIsStream = is_stream,
- haBufferMode = r_bmode,
- haFilePath = filepath,
- haBuffer = r_buf,
- haBuffers = r_spares,
- haOtherSide = Just write_side
- }
- read_side <- newMVar r_handle_
-
- addMVarFinalizer read_side (handleFinalizer read_side)
- return (DuplexHandle read_side write_side)
-
-
-initBufferState ReadHandle = ReadBuffer
-initBufferState _ = WriteBuffer
-
--- ---------------------------------------------------------------------------
--- Closing a handle
-
--- Computation `hClose hdl' makes handle `hdl' closed. Before the
--- computation finishes, any items buffered for output and not already
--- sent to the operating system are flushed as for `hFlush'.
-
--- For a duplex handle, we close&flush the write side, and just close
--- the read side.
-
-hClose :: Handle -> IO ()
-hClose h@(FileHandle m) = hClose' h m
-hClose h@(DuplexHandle r w) = hClose' h w >> hClose' h r
-
-hClose' h m = withHandle__' "hClose" h m $ hClose_help
-
--- hClose_help is also called by lazyRead (in PrelIO) when EOF is read
--- or an IO error occurs on a lazy stream. The semi-closed Handle is
--- then closed immediately. We have to be careful with DuplexHandles
--- though: we have to leave the closing to the finalizer in that case,
--- because the write side may still be in use.
-hClose_help :: Handle__ -> IO Handle__
-hClose_help handle_ =
- case haType handle_ of
- ClosedHandle -> return handle_
- _ -> do
- let fd = haFD handle_
- c_fd = fromIntegral fd
-
- flushWriteBufferOnly handle_
-
- -- close the file descriptor, but not when this is the read
- -- side of a duplex handle, and not when this is one of the
- -- std file handles.
- case haOtherSide handle_ of
- Nothing ->
- when (fd /= fd_stdin && fd /= fd_stdout && fd /= fd_stderr) $
- throwErrnoIfMinus1Retry_ "hClose"
-#ifdef mingw32_TARGET_OS
- (closeFd (haIsStream handle_) c_fd)
-#else
- (c_close c_fd)
-#endif
- Just _ -> return ()
-
- -- free the spare buffers
- writeIORef (haBuffers handle_) BufferListNil
-
- -- unlock it
- unlockFile c_fd
-
- -- we must set the fd to -1, because the finalizer is going
- -- to run eventually and try to close/unlock it.
- return (handle_{ haFD = -1,
- haType = ClosedHandle
- })
-
------------------------------------------------------------------------------
--- Detecting the size of a file
-
--- For a handle `hdl' which attached to a physical file, `hFileSize
--- hdl' returns the size of `hdl' in terms of the number of items
--- which can be read from `hdl'.
-
-hFileSize :: Handle -> IO Integer
-hFileSize handle =
- withHandle_ "hFileSize" handle $ \ handle_ -> do
- case haType handle_ of
- ClosedHandle -> ioe_closedHandle
- SemiClosedHandle -> ioe_closedHandle
- _ -> do flushWriteBufferOnly handle_
- r <- fdFileSize (haFD handle_)
- if r /= -1
- then return r
- else ioException (IOError Nothing InappropriateType "hFileSize"
- "not a regular file" Nothing)
-
--- ---------------------------------------------------------------------------
--- Detecting the End of Input
-
--- For a readable handle `hdl', `hIsEOF hdl' returns
--- `True' if no further input can be taken from `hdl' or for a
--- physical file, if the current I/O position is equal to the length of
--- the file. Otherwise, it returns `False'.
-
-hIsEOF :: Handle -> IO Bool
-hIsEOF handle =
- catch
- (do hLookAhead handle; return False)
- (\e -> if isEOFError e then return True else ioError e)
-
-isEOF :: IO Bool
-isEOF = hIsEOF stdin
-
--- ---------------------------------------------------------------------------
--- Looking ahead
-
--- hLookahead returns the next character from the handle without
--- removing it from the input buffer, blocking until a character is
--- available.
-
-hLookAhead :: Handle -> IO Char
-hLookAhead handle = do
- wantReadableHandle "hLookAhead" handle $ \handle_ -> do
- let ref = haBuffer handle_
- fd = haFD handle_
- is_line = haBufferMode handle_ == LineBuffering
- buf <- readIORef ref
-
- -- fill up the read buffer if necessary
- new_buf <- if bufferEmpty buf
- then fillReadBuffer fd is_line (haIsStream handle_) buf
- else return buf
-
- writeIORef ref new_buf
-
- (c,_) <- readCharFromBuffer (bufBuf buf) (bufRPtr buf)
- return c
-
--- ---------------------------------------------------------------------------
--- Buffering Operations
-
--- Three kinds of buffering are supported: line-buffering,
--- block-buffering or no-buffering. See GHC.IOBase for definition and
--- further explanation of what the type represent.
-
--- Computation `hSetBuffering hdl mode' sets the mode of buffering for
--- handle hdl on subsequent reads and writes.
---
--- * If mode is LineBuffering, line-buffering should be enabled if possible.
---
--- * If mode is `BlockBuffering size', then block-buffering
--- should be enabled if possible. The size of the buffer is n items
--- if size is `Just n' and is otherwise implementation-dependent.
---
--- * If mode is NoBuffering, then buffering is disabled if possible.
-
--- If the buffer mode is changed from BlockBuffering or
--- LineBuffering to NoBuffering, then any items in the output
--- buffer are written to the device, and any items in the input buffer
--- are discarded. The default buffering mode when a handle is opened
--- is implementation-dependent and may depend on the object which is
--- attached to that handle.
-
-hSetBuffering :: Handle -> BufferMode -> IO ()
-hSetBuffering handle mode =
- withAllHandles__ "hSetBuffering" handle $ \ handle_ -> do
- case haType handle_ of
- ClosedHandle -> ioe_closedHandle
- _ -> do
- {- Note:
- - we flush the old buffer regardless of whether
- the new buffer could fit the contents of the old buffer
- or not.
- - allow a handle's buffering to change even if IO has
- occurred (ANSI C spec. does not allow this, nor did
- the previous implementation of IO.hSetBuffering).
- - a non-standard extension is to allow the buffering
- of semi-closed handles to change [sof 6/98]
- -}
- flushBuffer handle_
-
- let state = initBufferState (haType handle_)
- new_buf <-
- case mode of
- -- we always have a 1-character read buffer for
- -- unbuffered handles: it's needed to
- -- support hLookAhead.
- NoBuffering -> allocateBuffer 1 ReadBuffer
- LineBuffering -> allocateBuffer dEFAULT_BUFFER_SIZE state
- BlockBuffering Nothing -> allocateBuffer dEFAULT_BUFFER_SIZE state
- BlockBuffering (Just n) | n <= 0 -> ioe_bufsiz n
- | otherwise -> allocateBuffer n state
- writeIORef (haBuffer handle_) new_buf
-
- -- for input terminals we need to put the terminal into
- -- cooked or raw mode depending on the type of buffering.
- is_tty <- fdIsTTY (haFD handle_)
- when (is_tty && isReadableHandleType (haType handle_)) $
- case mode of
-#ifndef mingw32_TARGET_OS
- -- 'raw' mode under win32 is a bit too specialised (and troublesome
- -- for most common uses), so simply disable its use here.
- NoBuffering -> setCooked (haFD handle_) False
-#endif
- _ -> setCooked (haFD handle_) True
-
- -- throw away spare buffers, they might be the wrong size
- writeIORef (haBuffers handle_) BufferListNil
-
- return (handle_{ haBufferMode = mode })
-
--- -----------------------------------------------------------------------------
--- hFlush
-
--- The action `hFlush hdl' causes any items buffered for output
--- in handle `hdl' to be sent immediately to the operating
--- system.
-
-hFlush :: Handle -> IO ()
-hFlush handle =
- wantWritableHandle "hFlush" handle $ \ handle_ -> do
- buf <- readIORef (haBuffer handle_)
- if bufferIsWritable buf && not (bufferEmpty buf)
- then do flushed_buf <- flushWriteBuffer (haFD handle_) (haIsStream handle_) buf
- writeIORef (haBuffer handle_) flushed_buf
- else return ()
-
-
--- -----------------------------------------------------------------------------
--- Repositioning Handles
-
-data HandlePosn = HandlePosn Handle HandlePosition
-
-instance Eq HandlePosn where
- (HandlePosn h1 p1) == (HandlePosn h2 p2) = p1==p2 && h1==h2
-
-instance Show HandlePosn where
- showsPrec p (HandlePosn h pos) =
- showsPrec p h . showString " at position " . shows pos
-
- -- HandlePosition is the Haskell equivalent of POSIX' off_t.
- -- We represent it as an Integer on the Haskell side, but
- -- cheat slightly in that hGetPosn calls upon a C helper
- -- that reports the position back via (merely) an Int.
-type HandlePosition = Integer
-
--- Computation `hGetPosn hdl' returns the current I/O position of
--- `hdl' as an abstract position. Computation `hSetPosn p' sets the
--- position of `hdl' to a previously obtained position `p'.
-
-hGetPosn :: Handle -> IO HandlePosn
-hGetPosn handle = do
- posn <- hTell handle
- return (HandlePosn handle posn)
-
-hSetPosn :: HandlePosn -> IO ()
-hSetPosn (HandlePosn h i) = hSeek h AbsoluteSeek i
-
--- ---------------------------------------------------------------------------
--- hSeek
-
-{-
-The action `hSeek hdl mode i' sets the position of handle
-`hdl' depending on `mode'. If `mode' is
-
- * 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.
-
-Some handles may not be seekable (see `hIsSeekable'), or only
-support a subset of the possible positioning operations (e.g. 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.
-
-Note:
- - when seeking using `SeekFromEnd', positive offsets (>=0) means
- seeking at or past EOF.
-
- - we possibly deviate from the report on the issue of seeking within
- the buffer and whether to flush it or not. The report isn't exactly
- clear here.
--}
-
-data SeekMode = AbsoluteSeek | RelativeSeek | SeekFromEnd
- deriving (Eq, Ord, Ix, Enum, Read, Show)
-
-hSeek :: Handle -> SeekMode -> Integer -> IO ()
-hSeek handle mode offset =
- wantSeekableHandle "hSeek" handle $ \ handle_ -> do
-# ifdef DEBUG_DUMP
- puts ("hSeek " ++ show (mode,offset) ++ "\n")
-# endif
- let ref = haBuffer handle_
- buf <- readIORef ref
- let r = bufRPtr buf
- w = bufWPtr buf
- fd = haFD handle_
-
- let do_seek =
- throwErrnoIfMinus1Retry_ "hSeek"
- (c_lseek (fromIntegral (haFD handle_)) (fromIntegral offset) whence)
-
- whence :: CInt
- whence = case mode of
- AbsoluteSeek -> sEEK_SET
- RelativeSeek -> sEEK_CUR
- SeekFromEnd -> sEEK_END
-
- if bufferIsWritable buf
- then do new_buf <- flushWriteBuffer fd (haIsStream handle_) buf
- writeIORef ref new_buf
- do_seek
- else do
-
- if mode == RelativeSeek && offset >= 0 && offset < fromIntegral (w - r)
- then writeIORef ref buf{ bufRPtr = r + fromIntegral offset }
- else do
-
- new_buf <- flushReadBuffer (haFD handle_) buf
- writeIORef ref new_buf
- do_seek
-
-
-hTell :: Handle -> IO Integer
-hTell handle =
- wantSeekableHandle "hGetPosn" handle $ \ handle_ -> do
-
-#if defined(mingw32_TARGET_OS)
- -- urgh, on Windows we have to worry about \n -> \r\n translation,
- -- so we can't easily calculate the file position using the
- -- current buffer size. Just flush instead.
- flushBuffer handle_
-#endif
- let fd = fromIntegral (haFD handle_)
- posn <- fromIntegral `liftM`
- throwErrnoIfMinus1Retry "hGetPosn"
- (c_lseek fd 0 sEEK_CUR)
-
- let ref = haBuffer handle_
- buf <- readIORef ref
-
- let real_posn
- | bufferIsWritable buf = posn + fromIntegral (bufWPtr buf)
- | otherwise = posn - fromIntegral (bufWPtr buf - bufRPtr buf)
-# ifdef DEBUG_DUMP
- puts ("\nhGetPosn: (fd, posn, real_posn) = " ++ show (fd, posn, real_posn) ++ "\n")
- puts (" (bufWPtr, bufRPtr) = " ++ show (bufWPtr buf, bufRPtr buf) ++ "\n")
-# endif
- return real_posn
-
--- -----------------------------------------------------------------------------
--- Handle Properties
-
--- A number of operations return information about the properties of a
--- handle. Each of these operations returns `True' if the handle has
--- the specified property, and `False' otherwise.
-
-hIsOpen :: Handle -> IO Bool
-hIsOpen handle =
- withHandle_ "hIsOpen" handle $ \ handle_ -> do
- case haType handle_ of
- ClosedHandle -> return False
- SemiClosedHandle -> return False
- _ -> return True
-
-hIsClosed :: Handle -> IO Bool
-hIsClosed handle =
- withHandle_ "hIsClosed" handle $ \ handle_ -> do
- case haType handle_ of
- ClosedHandle -> return True
- _ -> return False
-
-{- not defined, nor exported, but mentioned
- here for documentation purposes:
-
- hSemiClosed :: Handle -> IO Bool
- hSemiClosed h = do
- ho <- hIsOpen h
- hc <- hIsClosed h
- return (not (ho || hc))
--}
-
-hIsReadable :: Handle -> IO Bool
-hIsReadable (DuplexHandle _ _) = return True
-hIsReadable handle =
- withHandle_ "hIsReadable" handle $ \ handle_ -> do
- case haType handle_ of
- ClosedHandle -> ioe_closedHandle
- SemiClosedHandle -> ioe_closedHandle
- htype -> return (isReadableHandleType htype)
-
-hIsWritable :: Handle -> IO Bool
-hIsWritable (DuplexHandle _ _) = return False
-hIsWritable handle =
- withHandle_ "hIsWritable" handle $ \ handle_ -> do
- case haType handle_ of
- ClosedHandle -> ioe_closedHandle
- SemiClosedHandle -> ioe_closedHandle
- htype -> return (isWritableHandleType htype)
-
--- Querying how a handle buffers its data:
-
-hGetBuffering :: Handle -> IO BufferMode
-hGetBuffering handle =
- withHandle_ "hGetBuffering" handle $ \ handle_ -> do
- case haType handle_ of
- ClosedHandle -> ioe_closedHandle
- _ ->
- -- We're being non-standard here, and allow the buffering
- -- of a semi-closed handle to be queried. -- sof 6/98
- return (haBufferMode handle_) -- could be stricter..
-
-hIsSeekable :: Handle -> IO Bool
-hIsSeekable handle =
- withHandle_ "hIsSeekable" handle $ \ handle_ -> do
- case haType handle_ of
- ClosedHandle -> ioe_closedHandle
- SemiClosedHandle -> ioe_closedHandle
- AppendHandle -> return False
- _ -> do t <- fdType (haFD handle_)
- return (t == RegularFile
- && (haIsBin handle_
- || tEXT_MODE_SEEK_ALLOWED))
-
--- -----------------------------------------------------------------------------
--- Changing echo status
-
--- Non-standard GHC extension is to allow the echoing status
--- of a handles connected to terminals to be reconfigured:
-
-hSetEcho :: Handle -> Bool -> IO ()
-hSetEcho handle on = do
- isT <- hIsTerminalDevice handle
- if not isT
- then return ()
- else
- withHandle_ "hSetEcho" handle $ \ handle_ -> do
- case haType handle_ of
- ClosedHandle -> ioe_closedHandle
- _ -> setEcho (haFD handle_) on
-
-hGetEcho :: Handle -> IO Bool
-hGetEcho handle = do
- isT <- hIsTerminalDevice handle
- if not isT
- then return False
- else
- withHandle_ "hGetEcho" handle $ \ handle_ -> do
- case haType handle_ of
- ClosedHandle -> ioe_closedHandle
- _ -> getEcho (haFD handle_)
-
-hIsTerminalDevice :: Handle -> IO Bool
-hIsTerminalDevice handle = do
- withHandle_ "hIsTerminalDevice" handle $ \ handle_ -> do
- case haType handle_ of
- ClosedHandle -> ioe_closedHandle
- _ -> fdIsTTY (haFD handle_)
-
--- -----------------------------------------------------------------------------
--- hSetBinaryMode
-
--- | On Windows, reading a file in text mode (which is the default) will
--- translate CRLF to LF, and writing will translate LF to CRLF. This
--- is usually what you want with text files. With binary files this is
--- undesirable; also, as usual under Microsoft operating systems, text
--- mode treats control-Z as EOF. Setting binary mode using
--- 'hSetBinaryMode' turns off all special treatment of end-of-line and
--- end-of-file characters.
---
-hSetBinaryMode :: Handle -> Bool -> IO ()
-hSetBinaryMode handle bin =
- withAllHandles__ "hSetBinaryMode" handle $ \ handle_ ->
- do throwErrnoIfMinus1_ "hSetBinaryMode"
- (setmode (fromIntegral (haFD handle_)) bin)
- return handle_{haIsBin=bin}
-
-foreign import ccall unsafe "__hscore_setmode"
- setmode :: CInt -> Bool -> IO CInt
-
--- -----------------------------------------------------------------------------
--- Duplicating a Handle
-
--- |Returns a duplicate of the original handle, with its own buffer
--- and file pointer. The original handle's buffer is flushed, including
--- discarding any input data, before the handle is duplicated.
-
-hDuplicate :: Handle -> IO Handle
-hDuplicate h@(FileHandle m) = do
- new_h_ <- withHandle' "hDuplicate" h m (dupHandle_ Nothing)
- new_m <- newMVar new_h_
- return (FileHandle new_m)
-hDuplicate h@(DuplexHandle r w) = do
- new_w_ <- withHandle' "hDuplicate" h w (dupHandle_ Nothing)
- new_w <- newMVar new_w_
- new_r_ <- withHandle' "hDuplicate" h r (dupHandle_ (Just new_w))
- new_r <- newMVar new_r_
- return (DuplexHandle new_r new_w)
-
-dupHandle_ other_side h_ = do
- -- flush the buffer first, so we don't have to copy its contents
- flushBuffer h_
- new_fd <- c_dup (fromIntegral (haFD h_))
- buffer <- allocateBuffer dEFAULT_BUFFER_SIZE (initBufferState (haType h_))
- ioref <- newIORef buffer
- ioref_buffers <- newIORef BufferListNil
-
- let new_handle_ = h_{ haFD = fromIntegral new_fd,
- haBuffer = ioref,
- haBuffers = ioref_buffers,
- haOtherSide = other_side }
- return (h_, new_handle_)
-
--- -----------------------------------------------------------------------------
--- Replacing a Handle
-
-{- |
-Makes the second handle a duplicate of the first handle. The second
-handle will be closed first, if it is not already.
-
-This can be used to retarget the standard Handles, for example:
-
-> do h <- openFile "mystdout" WriteMode
-> hDuplicateTo h stdout
--}
-
-hDuplicateTo :: Handle -> Handle -> IO ()
-hDuplicateTo h1@(FileHandle m1) h2@(FileHandle m2) = do
- withHandle__' "hDuplicateTo" h2 m2 $ \h2_ -> do
- _ <- hClose_help h2_
- withHandle' "hDuplicateTo" h1 m1 (dupHandle_ Nothing)
-hDuplicateTo h1@(DuplexHandle r1 w1) h2@(DuplexHandle r2 w2) = do
- withHandle__' "hDuplicateTo" h2 w2 $ \w2_ -> do
- _ <- hClose_help w2_
- withHandle' "hDuplicateTo" h1 r1 (dupHandle_ Nothing)
- withHandle__' "hDuplicateTo" h2 r2 $ \r2_ -> do
- _ <- hClose_help r2_
- withHandle' "hDuplicateTo" h1 r1 (dupHandle_ (Just w1))
-hDuplicateTo h1 _ =
- ioException (IOError (Just h1) IllegalOperation "hDuplicateTo"
- "handles are incompatible" Nothing)
-
--- ---------------------------------------------------------------------------
--- debugging
-
-#ifdef DEBUG_DUMP
-puts :: String -> IO ()
-puts s = withCString s $ \cstr -> do write_off_ba 1 False cstr 0 (fromIntegral (length s))
- return ()
-#endif
-
--- -----------------------------------------------------------------------------
--- wrappers to platform-specific constants:
-
-foreign import ccall unsafe "__hscore_supportsTextMode"
- tEXT_MODE_SEEK_ALLOWED :: Bool
-
-foreign import ccall unsafe "__hscore_bufsiz" dEFAULT_BUFFER_SIZE :: Int
-foreign import ccall unsafe "__hscore_seek_cur" sEEK_CUR :: CInt
-foreign import ccall unsafe "__hscore_seek_set" sEEK_SET :: CInt
-foreign import ccall unsafe "__hscore_seek_end" sEEK_END :: CInt
+import GHC.IO.IOMode
+import GHC.IO.Handle
+import GHC.IO.Handle.Internals
+import GHC.IO.Handle.FD
projects / ghc-base.git / blobdiff