    {-# LANGUAGE Trustworthy #-}
    {-# LANGUAGE CPP
               , NoImplicitPrelude
               , RecordWildCards
               , NondecreasingIndentation
      #-}
    {-# OPTIONS_GHC -Wno-unused-matches #-}

    -----------------------------------------------------------------------------
    -- |
    -- Module      :  GHC.Internal.IO.Handle
    -- Copyright   :  (c) The University of Glasgow, 1994-2009
    -- License     :  see libraries/base/LICENSE
    --
    -- Maintainer  :  libraries@haskell.org
    -- Stability   :  provisional
    -- Portability :  non-portable
    --
    -- External API for GHC's Handle implementation
    --
    -----------------------------------------------------------------------------

    module GHC.Internal.IO.Handle (
       Handle,
       BufferMode(..),

       mkFileHandle, mkDuplexHandle,

       hFileSize, hSetFileSize, hIsEOF, isEOF, hLookAhead,
       hSetBuffering, hSetBinaryMode, hSetEncoding, hGetEncoding,
       hFlush, hFlushAll, hDuplicate, hDuplicateTo,

       hClose, hClose_help,

       LockMode(..), hLock, hTryLock,

       HandlePosition, HandlePosn(..), hGetPosn, hSetPosn,
       SeekMode(..), hSeek, hTell,

       hIsOpen, hIsClosed, hIsReadable, hIsWritable, hGetBuffering, hIsSeekable,
       hSetEcho, hGetEcho, hIsTerminalDevice,

       hSetNewlineMode, Newline(..), NewlineMode(..), nativeNewline,
       noNewlineTranslation, universalNewlineMode, nativeNewlineMode,

       hShow,

       hWaitForInput, hGetChar, hGetLine, hGetContents, hGetContents', hPutChar, hPutStr,

       hGetBuf, hGetBufNonBlocking, hPutBuf, hPutBufNonBlocking
     ) where

    import GHC.Internal.IO
    import GHC.Internal.IO.Exception
    import GHC.Internal.IO.Encoding
    import GHC.Internal.IO.Buffer
    import GHC.Internal.IO.BufferedIO ( BufferedIO )
    import GHC.Internal.IO.Device as IODevice
    import GHC.Internal.IO.StdHandles
    import GHC.Internal.IO.SubSystem
    import GHC.Internal.IO.Handle.Lock
    import GHC.Internal.IO.Handle.Types
    import GHC.Internal.IO.Handle.Internals
    import GHC.Internal.IO.Handle.Text
    import qualified GHC.Internal.IO.BufferedIO as Buffered

    import GHC.Internal.Base
    import GHC.Internal.Exception
    import GHC.Internal.MVar
    import GHC.Internal.IORef
    import GHC.Internal.Show
    import GHC.Internal.Num
    import GHC.Internal.Real
    import GHC.Internal.Data.Maybe
    import GHC.Internal.Data.Typeable

    -- ---------------------------------------------------------------------------
    -- Closing a handle

    -- | 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.
    hClose :: Handle -> IO ()
    hClose :: Handle -> IO ()
    hClose = Handle -> IO ()
    hClose_impl

    -----------------------------------------------------------------------------
    -- Detecting and changing the size of a file

    -- | For a handle @hdl@ which attached to a physical file,
    -- 'hFileSize' @hdl@ returns the size of that file in 8-bit bytes.

    hFileSize :: Handle -> IO Integer
    hFileSize :: Handle -> IO Integer
    hFileSize Handle
    handle =
        String -> Handle -> (Handle__ -> IO Integer) -> IO Integer
    forall a. String -> Handle -> (Handle__ -> IO a) -> IO a
    withHandle_ String
    "hFileSize" Handle
    handle ((Handle__ -> IO Integer) -> IO Integer)
    -> (Handle__ -> IO Integer) -> IO Integer
    forall a b. (a -> b) -> a -> b
    $ \ handle_ :: Handle__
    handle_@Handle__{haDevice :: ()
    haDevice=dev
    dev} -> do
        case Handle__ -> HandleType
    haType Handle__
    handle_ of
          HandleType
    ClosedHandle              -> IO Integer
    forall a. IO a
    ioe_closedHandle
          HandleType
    SemiClosedHandle          -> IO Integer
    forall a. IO a
    ioe_semiclosedHandle
          HandleType
    _ -> do Handle__ -> IO ()
    flushWriteBuffer Handle__
    handle_
                  r <- dev -> IO Integer
    forall a. IODevice a => a -> IO Integer
    IODevice.getSize dev
    dev
                  debugIO $ "hFileSize: " ++ show r ++ " " ++ show handle
                  if r /= -1
                    then return r
                    else ioException (IOError Nothing InappropriateType "hFileSize"
                                      "not a regular file" Nothing Nothing)

    -- | 'hSetFileSize' @hdl@ @size@ truncates the physical file with handle @hdl@ to @size@ bytes.

    hSetFileSize :: Handle -> Integer -> IO ()
    hSetFileSize :: Handle -> Integer -> IO ()
    hSetFileSize Handle
    handle Integer
    size =
        String -> Handle -> (Handle__ -> IO ()) -> IO ()
    forall a. String -> Handle -> (Handle__ -> IO a) -> IO a
    withHandle_ String
    "hSetFileSize" Handle
    handle ((Handle__ -> IO ()) -> IO ()) -> (Handle__ -> IO ()) -> IO ()
    forall a b. (a -> b) -> a -> b
    $ \ handle_ :: Handle__
    handle_@Handle__{haDevice :: ()
    haDevice=dev
    dev} -> do
        case Handle__ -> HandleType
    haType Handle__
    handle_ of
          HandleType
    ClosedHandle              -> IO ()
    forall a. IO a
    ioe_closedHandle
          HandleType
    SemiClosedHandle          -> IO ()
    forall a. IO a
    ioe_semiclosedHandle
          HandleType
    _ -> do Handle__ -> IO ()
    flushWriteBuffer Handle__
    handle_
                  dev -> Integer -> IO ()
    forall a. IODevice a => a -> Integer -> IO ()
    IODevice.setSize dev
    dev Integer
    size
                  () -> IO ()
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return ()

    -- ---------------------------------------------------------------------------
    -- 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'.
    --
    -- NOTE: 'hIsEOF' may block, because it has to attempt to read from
    -- the stream to determine whether there is any more data to be read.

    hIsEOF :: Handle -> IO Bool
    hIsEOF :: Handle -> IO Bool
    hIsEOF Handle
    handle = String -> Handle -> (Handle__ -> IO Bool) -> IO Bool
    forall a. String -> Handle -> (Handle__ -> IO a) -> IO a
    wantReadableHandle_ String
    "hIsEOF" Handle
    handle ((Handle__ -> IO Bool) -> IO Bool)
    -> (Handle__ -> IO Bool) -> IO Bool
    forall a b. (a -> b) -> a -> b
    $ \Handle__{dev
    Maybe (MVar Handle__)
    Maybe TextEncoding
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    IORef (dec_state, Buffer Word8)
    IORef (Buffer CharBufElem)
    IORef (Buffer Word8)
    IORef (BufferList CharBufElem)
    Newline
    BufferMode
    HandleType
    haDevice :: ()
    haType :: Handle__ -> HandleType
    haDevice :: dev
    haType :: HandleType
    haByteBuffer :: IORef (Buffer Word8)
    haBufferMode :: BufferMode
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haCharBuffer :: IORef (Buffer CharBufElem)
    haBuffers :: IORef (BufferList CharBufElem)
    haEncoder :: Maybe (TextEncoder enc_state)
    haDecoder :: Maybe (TextDecoder dec_state)
    haCodec :: Maybe TextEncoding
    haInputNL :: Newline
    haOutputNL :: Newline
    haOtherSide :: Maybe (MVar Handle__)
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haOutputNL :: Handle__ -> Newline
    haInputNL :: Handle__ -> Newline
    haCodec :: Handle__ -> Maybe TextEncoding
    haDecoder :: ()
    haEncoder :: ()
    haBuffers :: Handle__ -> IORef (BufferList CharBufElem)
    haCharBuffer :: Handle__ -> IORef (Buffer CharBufElem)
    haLastDecode :: ()
    haBufferMode :: Handle__ -> BufferMode
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    ..} -> do

      cbuf <- IORef (Buffer CharBufElem) -> IO (Buffer CharBufElem)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer CharBufElem)
    haCharBuffer
      if not (isEmptyBuffer cbuf) then return False else do

      bbuf <- readIORef haByteBuffer
      if not (isEmptyBuffer bbuf) then return False else do

      -- NB. do no decoding, just fill the byte buffer; see #3808
      (r,bbuf') <- Buffered.fillReadBuffer haDevice bbuf
      if r == 0
         then return True
         else do writeIORef haByteBuffer bbuf'
                 return False

    -- ---------------------------------------------------------------------------
    -- isEOF

    -- | The computation 'isEOF' is identical to 'hIsEOF',
    -- except that it works only on 'stdin'.

    isEOF :: IO Bool
    isEOF :: IO Bool
    isEOF = Handle -> IO Bool
    hIsEOF Handle
    stdin

    -- ---------------------------------------------------------------------------
    -- Looking ahead

    -- | Computation 'hLookAhead' returns the next character from the handle
    -- without removing it from the input buffer, blocking until a character
    -- is available.
    --
    -- This operation may fail with:
    --
    --  * 'GHC.Internal.System.IO.Error.isEOFError' if the end of file has been reached.

    hLookAhead :: Handle -> IO Char
    hLookAhead :: Handle -> IO CharBufElem
    hLookAhead Handle
    handle =
      String -> Handle -> (Handle__ -> IO CharBufElem) -> IO CharBufElem
    forall a. String -> Handle -> (Handle__ -> IO a) -> IO a
    wantReadableHandle_ String
    "hLookAhead"  Handle
    handle Handle__ -> IO CharBufElem
    hLookAhead_

    -- ---------------------------------------------------------------------------
    -- Buffering Operations

    -- Three kinds of buffering are supported: line-buffering,
    -- block-buffering or no-buffering.  See GHC.Internal.IO.Handle 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 the buffer mode is changed from 'BlockBuffering' or
    -- 'LineBuffering' to 'NoBuffering', then
    --
    --  * if @hdl@ is writable, the buffer is flushed as for 'hFlush';
    --
    --  * if @hdl@ is not writable, the contents of the buffer are discarded.
    --
    -- This operation may fail with:
    --
    --  * 'GHC.Internal.System.IO.Error.isPermissionError' if the handle has already been used
    --    for reading or writing and the implementation does not allow the
    --    buffering mode to be changed.

    hSetBuffering :: Handle -> BufferMode -> IO ()
    hSetBuffering :: Handle -> BufferMode -> IO ()
    hSetBuffering Handle
    handle BufferMode
    mode =
      String -> Handle -> (Handle__ -> IO Handle__) -> IO ()
    withAllHandles__ String
    "hSetBuffering" Handle
    handle ((Handle__ -> IO Handle__) -> IO ())
    -> (Handle__ -> IO Handle__) -> IO ()
    forall a b. (a -> b) -> a -> b
    $ \ handle_ :: Handle__
    handle_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe TextEncoding
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    IORef (dec_state, Buffer Word8)
    IORef (Buffer CharBufElem)
    IORef (Buffer Word8)
    IORef (BufferList CharBufElem)
    Newline
    BufferMode
    HandleType
    haDevice :: ()
    haType :: Handle__ -> HandleType
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haOutputNL :: Handle__ -> Newline
    haInputNL :: Handle__ -> Newline
    haCodec :: Handle__ -> Maybe TextEncoding
    haDecoder :: ()
    haEncoder :: ()
    haBuffers :: Handle__ -> IORef (BufferList CharBufElem)
    haCharBuffer :: Handle__ -> IORef (Buffer CharBufElem)
    haLastDecode :: ()
    haBufferMode :: Handle__ -> BufferMode
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haDevice :: dev
    haType :: HandleType
    haByteBuffer :: IORef (Buffer Word8)
    haBufferMode :: BufferMode
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haCharBuffer :: IORef (Buffer CharBufElem)
    haBuffers :: IORef (BufferList CharBufElem)
    haEncoder :: Maybe (TextEncoder enc_state)
    haDecoder :: Maybe (TextDecoder dec_state)
    haCodec :: Maybe TextEncoding
    haInputNL :: Newline
    haOutputNL :: Newline
    haOtherSide :: Maybe (MVar Handle__)
    ..} -> do
      case HandleType
    haType of
        HandleType
    ClosedHandle -> IO Handle__
    forall a. IO a
    ioe_closedHandle
        HandleType
    _ -> do
             if BufferMode
    mode BufferMode -> BufferMode -> Bool
    forall a. Eq a => a -> a -> Bool
    == BufferMode
    haBufferMode then Handle__ -> IO Handle__
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Handle__
    handle_ else do

             -- See [note Buffer Sizing] in GHC.Internal.IO.Handle.Types

              -- check for errors:
              case BufferMode
    mode of
                  BlockBuffering (Just Int
    n) | Int
    n Int -> Int -> Bool
    forall a. Ord a => a -> a -> Bool
    <= Int
    0    -> Int -> IO ()
    forall a. Int -> IO a
    ioe_bufsiz Int
    n
                  BufferMode
    _ -> () -> IO ()
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return ()

              -- for input terminals we need to put the terminal into
              -- cooked or raw mode depending on the type of buffering.
              is_tty <- dev -> IO Bool
    forall a. IODevice a => a -> IO Bool
    IODevice.isTerminal dev
    haDevice
              when (is_tty && isReadableHandleType haType) $
                    case mode of
    #if !defined(mingw32_HOST_OS)
            -- 'raw' mode under win32 is a bit too specialised (and troublesome
            -- for most common uses), so simply disable its use here when not using
            -- WinIO.
                      BufferMode
    NoBuffering -> dev -> Bool -> IO ()
    forall a. IODevice a => a -> Bool -> IO ()
    IODevice.setRaw dev
    haDevice Bool
    True
    #else
                      NoBuffering -> return () <!> IODevice.setRaw haDevice True
    #endif
                      BufferMode
    _           -> dev -> Bool -> IO ()
    forall a. IODevice a => a -> Bool -> IO ()
    IODevice.setRaw dev
    haDevice Bool
    False

              -- throw away spare buffers, they might be the wrong size
              writeIORef haBuffers BufferListNil

              return Handle__{ haBufferMode = mode,.. }

    -- -----------------------------------------------------------------------------
    -- hSetEncoding

    -- | The action 'hSetEncoding' @hdl@ @encoding@ changes the text encoding
    -- for the handle @hdl@ to @encoding@.  The default encoding when a 'Handle' is
    -- created is 'GHC.Internal.System.IO.localeEncoding', namely the default encoding for the
    -- current locale.
    --
    -- To create a 'Handle' with no encoding at all, use 'openBinaryFile'.  To
    -- stop further encoding or decoding on an existing 'Handle', use
    -- 'hSetBinaryMode'.
    --
    -- 'hSetEncoding' may need to flush buffered data in order to change
    -- the encoding.
    --
    hSetEncoding :: Handle -> TextEncoding -> IO ()
    hSetEncoding :: Handle -> TextEncoding -> IO ()
    hSetEncoding Handle
    hdl TextEncoding
    encoding =
      String -> Handle -> (Handle__ -> IO Handle__) -> IO ()
    withAllHandles__ String
    "hSetEncoding" Handle
    hdl ((Handle__ -> IO Handle__) -> IO ())
    -> (Handle__ -> IO Handle__) -> IO ()
    forall a b. (a -> b) -> a -> b
    $ \h_ :: Handle__
    h_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe TextEncoding
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    IORef (dec_state, Buffer Word8)
    IORef (Buffer CharBufElem)
    IORef (Buffer Word8)
    IORef (BufferList CharBufElem)
    Newline
    BufferMode
    HandleType
    haDevice :: ()
    haType :: Handle__ -> HandleType
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haOutputNL :: Handle__ -> Newline
    haInputNL :: Handle__ -> Newline
    haCodec :: Handle__ -> Maybe TextEncoding
    haDecoder :: ()
    haEncoder :: ()
    haBuffers :: Handle__ -> IORef (BufferList CharBufElem)
    haCharBuffer :: Handle__ -> IORef (Buffer CharBufElem)
    haLastDecode :: ()
    haBufferMode :: Handle__ -> BufferMode
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haDevice :: dev
    haType :: HandleType
    haByteBuffer :: IORef (Buffer Word8)
    haBufferMode :: BufferMode
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haCharBuffer :: IORef (Buffer CharBufElem)
    haBuffers :: IORef (BufferList CharBufElem)
    haEncoder :: Maybe (TextEncoder enc_state)
    haDecoder :: Maybe (TextDecoder dec_state)
    haCodec :: Maybe TextEncoding
    haInputNL :: Newline
    haOutputNL :: Newline
    haOtherSide :: Maybe (MVar Handle__)
    ..} -> do
        Handle__ -> IO ()
    flushCharBuffer Handle__
    h_
        Handle__ -> IO ()
    closeTextCodecs Handle__
    h_
        Maybe TextEncoding
    -> HandleType
    -> (forall es ds.
        Maybe (TextEncoder es) -> Maybe (TextDecoder ds) -> IO Handle__)
    -> IO Handle__
    forall a.
    Maybe TextEncoding
    -> HandleType
    -> (forall es ds.
        Maybe (TextEncoder es) -> Maybe (TextDecoder ds) -> IO a)
    -> IO a
    openTextEncoding (TextEncoding -> Maybe TextEncoding
    forall a. a -> Maybe a
    Just TextEncoding
    encoding) HandleType
    haType ((forall es ds.
      Maybe (TextEncoder es) -> Maybe (TextDecoder ds) -> IO Handle__)
     -> IO Handle__)
    -> (forall es ds.
        Maybe (TextEncoder es) -> Maybe (TextDecoder ds) -> IO Handle__)
    -> IO Handle__
    forall a b. (a -> b) -> a -> b
    $ \ Maybe (TextEncoder es)
    mb_encoder Maybe (TextDecoder ds)
    mb_decoder -> do
        bbuf <- IORef (Buffer Word8) -> IO (Buffer Word8)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Word8)
    haByteBuffer
        ref <- newIORef (errorWithoutStackTrace "last_decode")
        return (Handle__{ haLastDecode = ref,
                          haDecoder = mb_decoder,
                          haEncoder = mb_encoder,
                          haCodec   = Just encoding, .. })

    -- | Return the current 'TextEncoding' for the specified 'Handle', or
    -- 'Nothing' if the 'Handle' is in binary mode.
    --
    -- Note that the 'TextEncoding' remembers nothing about the state of
    -- the encoder/decoder in use on this 'Handle'.  For example, if the
    -- encoding in use is UTF-16, then using 'hGetEncoding' and
    -- 'hSetEncoding' to save and restore the encoding may result in an
    -- extra byte-order-mark being written to the file.
    --
    hGetEncoding :: Handle -> IO (Maybe TextEncoding)
    hGetEncoding :: Handle -> IO (Maybe TextEncoding)
    hGetEncoding Handle
    hdl =
      String
    -> Handle
    -> (Handle__ -> IO (Maybe TextEncoding))
    -> IO (Maybe TextEncoding)
    forall a. String -> Handle -> (Handle__ -> IO a) -> IO a
    withHandle_ String
    "hGetEncoding" Handle
    hdl ((Handle__ -> IO (Maybe TextEncoding)) -> IO (Maybe TextEncoding))
    -> (Handle__ -> IO (Maybe TextEncoding)) -> IO (Maybe TextEncoding)
    forall a b. (a -> b) -> a -> b
    $ \h_ :: Handle__
    h_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe TextEncoding
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    IORef (dec_state, Buffer Word8)
    IORef (Buffer CharBufElem)
    IORef (Buffer Word8)
    IORef (BufferList CharBufElem)
    Newline
    BufferMode
    HandleType
    haDevice :: ()
    haType :: Handle__ -> HandleType
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haOutputNL :: Handle__ -> Newline
    haInputNL :: Handle__ -> Newline
    haCodec :: Handle__ -> Maybe TextEncoding
    haDecoder :: ()
    haEncoder :: ()
    haBuffers :: Handle__ -> IORef (BufferList CharBufElem)
    haCharBuffer :: Handle__ -> IORef (Buffer CharBufElem)
    haLastDecode :: ()
    haBufferMode :: Handle__ -> BufferMode
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haDevice :: dev
    haType :: HandleType
    haByteBuffer :: IORef (Buffer Word8)
    haBufferMode :: BufferMode
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haCharBuffer :: IORef (Buffer CharBufElem)
    haBuffers :: IORef (BufferList CharBufElem)
    haEncoder :: Maybe (TextEncoder enc_state)
    haDecoder :: Maybe (TextDecoder dec_state)
    haCodec :: Maybe TextEncoding
    haInputNL :: Newline
    haOutputNL :: Newline
    haOtherSide :: Maybe (MVar Handle__)
    ..} -> Maybe TextEncoding -> IO (Maybe TextEncoding)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Maybe TextEncoding
    haCodec

    -- -----------------------------------------------------------------------------
    -- hFlush

    -- | The action 'hFlush' @hdl@ causes any items buffered for output
    -- in handle @hdl@ to be sent immediately to the operating system.
    --
    -- This operation may fail with:
    --
    --  * 'GHC.Internal.System.IO.Error.isFullError' if the device is full;
    --
    --  * 'GHC.Internal.System.IO.Error.isPermissionError' if a system resource limit would be
    --    exceeded. It is unspecified whether the characters in the buffer are
    --    discarded or retained under these circumstances.

    hFlush :: Handle -> IO ()
    hFlush :: Handle -> IO ()
    hFlush Handle
    handle = String -> Handle -> (Handle__ -> IO ()) -> IO ()
    forall a. String -> Handle -> (Handle__ -> IO a) -> IO a
    wantWritableHandle String
    "hFlush" Handle
    handle Handle__ -> IO ()
    flushWriteBuffer

    -- | The action 'hFlushAll' @hdl@ flushes all buffered data in @hdl@,
    -- including any buffered read data.  Buffered read data is flushed
    -- by seeking the file position back to the point before the buffered
    -- data was read, and hence only works if @hdl@ is seekable (see
    -- 'hIsSeekable').
    --
    -- This operation may fail with:
    --
    --  * 'GHC.Internal.System.IO.Error.isFullError' if the device is full;
    --
    --  * 'GHC.Internal.System.IO.Error.isPermissionError' if a system resource limit would be
    --    exceeded. It is unspecified whether the characters in the buffer are
    --    discarded or retained under these circumstances;
    --
    --  * 'GHC.Internal.System.IO.Error.isIllegalOperation' if @hdl@ has buffered read data, and
    --    is not seekable.

    hFlushAll :: Handle -> IO ()
    hFlushAll :: Handle -> IO ()
    hFlushAll Handle
    handle = String -> Handle -> (Handle__ -> IO ()) -> IO ()
    forall a. String -> Handle -> (Handle__ -> IO a) -> IO a
    withHandle_ String
    "hFlushAll" Handle
    handle Handle__ -> IO ()
    flushBuffer

    -- -----------------------------------------------------------------------------
    -- Repositioning Handles

    data HandlePosn = HandlePosn Handle HandlePosition

    -- | @since base-4.1.0.0
    instance Eq HandlePosn where
        (HandlePosn Handle
    h1 Integer
    p1) == :: HandlePosn -> HandlePosn -> Bool
    == (HandlePosn Handle
    h2 Integer
    p2) = Integer
    p1Integer -> Integer -> Bool
    forall a. Eq a => a -> a -> Bool
    ==Integer
    p2 Bool -> Bool -> Bool
    && Handle
    h1Handle -> Handle -> Bool
    forall a. Eq a => a -> a -> Bool
    ==Handle
    h2

    -- | @since base-4.1.0.0
    instance Show HandlePosn where
       showsPrec :: Int -> HandlePosn -> String -> String
    showsPrec Int
    p (HandlePosn Handle
    h Integer
    pos) =
            Int -> Handle -> String -> String
    forall a. Show a => Int -> a -> String -> String
    showsPrec Int
    p Handle
    h (String -> String) -> (String -> String) -> String -> String
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . String -> String -> String
    showString String
    " at position " (String -> String) -> (String -> String) -> String -> String
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Integer -> String -> String
    forall a. Show a => a -> String -> String
    shows Integer
    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 a value of the abstract type 'HandlePosn'.

    hGetPosn :: Handle -> IO HandlePosn
    hGetPosn :: Handle -> IO HandlePosn
    hGetPosn Handle
    handle = do
        posn <- Handle -> IO Integer
    hTell Handle
    handle
        return (HandlePosn handle posn)

    -- | 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:
    --
    --  * 'GHC.Internal.System.IO.Error.isPermissionError' if a system resource limit would be
    --    exceeded.

    hSetPosn :: HandlePosn -> IO ()
    hSetPosn :: HandlePosn -> IO ()
    hSetPosn (HandlePosn Handle
    h Integer
    i) = Handle -> SeekMode -> Integer -> IO ()
    hSeek Handle
    h SeekMode
    AbsoluteSeek Integer
    i

    -- ---------------------------------------------------------------------------
    -- hSeek

    {- 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.
    -}

    -- | 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:
    --
    --  * 'GHC.Internal.System.IO.Error.isIllegalOperationError' if the Handle is not seekable,
    --    or does not support the requested seek mode.
    --
    --  * 'GHC.Internal.System.IO.Error.isPermissionError' if a system resource limit would be
    --    exceeded.

    hSeek :: Handle -> SeekMode -> Integer -> IO ()
    hSeek :: Handle -> SeekMode -> Integer -> IO ()
    hSeek Handle
    handle SeekMode
    mode Integer
    offset =
        String -> Handle -> (Handle__ -> IO ()) -> IO ()
    forall a. String -> Handle -> (Handle__ -> IO a) -> IO a
    wantSeekableHandle String
    "hSeek" Handle
    handle ((Handle__ -> IO ()) -> IO ()) -> (Handle__ -> IO ()) -> IO ()
    forall a b. (a -> b) -> a -> b
    $ \ handle_ :: Handle__
    handle_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe TextEncoding
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    IORef (dec_state, Buffer Word8)
    IORef (Buffer CharBufElem)
    IORef (Buffer Word8)
    IORef (BufferList CharBufElem)
    Newline
    BufferMode
    HandleType
    haDevice :: ()
    haType :: Handle__ -> HandleType
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haOutputNL :: Handle__ -> Newline
    haInputNL :: Handle__ -> Newline
    haCodec :: Handle__ -> Maybe TextEncoding
    haDecoder :: ()
    haEncoder :: ()
    haBuffers :: Handle__ -> IORef (BufferList CharBufElem)
    haCharBuffer :: Handle__ -> IORef (Buffer CharBufElem)
    haLastDecode :: ()
    haBufferMode :: Handle__ -> BufferMode
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haDevice :: dev
    haType :: HandleType
    haByteBuffer :: IORef (Buffer Word8)
    haBufferMode :: BufferMode
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haCharBuffer :: IORef (Buffer CharBufElem)
    haBuffers :: IORef (BufferList CharBufElem)
    haEncoder :: Maybe (TextEncoder enc_state)
    haDecoder :: Maybe (TextDecoder dec_state)
    haCodec :: Maybe TextEncoding
    haInputNL :: Newline
    haOutputNL :: Newline
    haOtherSide :: Maybe (MVar Handle__)
    ..} -> do
        String -> IO ()
    debugIO (String
    "hSeek " String -> String -> String
    forall a. [a] -> [a] -> [a]
    ++ (SeekMode, Integer) -> String
    forall a. Show a => a -> String
    show (SeekMode
    mode,Integer
    offset))
        cbuf <- IORef (Buffer CharBufElem) -> IO (Buffer CharBufElem)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer CharBufElem)
    haCharBuffer
        bbuf <- readIORef haByteBuffer
        debugIO $ "hSeek - bbuf:" ++ summaryBuffer bbuf
        debugIO $ "hSeek - cbuf:" ++ summaryBuffer cbuf

        if isWriteBuffer cbuf
            then do flushWriteBuffer handle_
                    new_offset <- IODevice.seek haDevice mode offset
                    -- buffer has been updated, need to re-read it
                    bbuf1 <- readIORef haByteBuffer
                    let bbuf2 = Buffer Word8
    bbuf1{ bufOffset = fromIntegral new_offset }
                    debugIO $ "hSeek - seek:: " ++ show offset ++
                              " - " ++ show new_offset
                    debugIO $ "hSeek - wr flush bbuf1:" ++ summaryBuffer bbuf2
                    writeIORef haByteBuffer bbuf2
            else do

        let r = Buffer CharBufElem -> Int
    forall e. Buffer e -> Int
    bufL Buffer CharBufElem
    cbuf; w = Buffer CharBufElem -> Int
    forall e. Buffer e -> Int
    bufR Buffer CharBufElem
    cbuf
        if mode == RelativeSeek && isNothing haDecoder &&
           offset >= 0 && offset < fromIntegral (w - r)
            then writeIORef haCharBuffer cbuf{ bufL = r + fromIntegral offset }
            else do

        flushCharReadBuffer handle_
        flushByteReadBuffer handle_
        -- read the updated values
        bbuf2 <- readIORef haByteBuffer
        new_offset <- IODevice.seek haDevice mode offset
        debugIO $ "hSeek after: " ++ show new_offset
        writeIORef haByteBuffer bbuf2{ bufOffset = fromIntegral new_offset }

    -- | Computation 'hTell' @hdl@ returns the current position of the
    -- handle @hdl@, as the number of bytes from the beginning of
    -- the file.  The value returned may be subsequently passed to
    -- 'hSeek' to reposition the handle to the current position.
    --
    -- This operation may fail with:
    --
    --  * 'GHC.Internal.System.IO.Error.isIllegalOperationError' if the Handle is not seekable.
    --
    hTell :: Handle -> IO Integer
    hTell :: Handle -> IO Integer
    hTell Handle
    handle =
        String -> Handle -> (Handle__ -> IO Integer) -> IO Integer
    forall a. String -> Handle -> (Handle__ -> IO a) -> IO a
    wantSeekableHandle String
    "hGetPosn" Handle
    handle ((Handle__ -> IO Integer) -> IO Integer)
    -> (Handle__ -> IO Integer) -> IO Integer
    forall a b. (a -> b) -> a -> b
    $ \ handle_ :: Handle__
    handle_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe TextEncoding
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    IORef (dec_state, Buffer Word8)
    IORef (Buffer CharBufElem)
    IORef (Buffer Word8)
    IORef (BufferList CharBufElem)
    Newline
    BufferMode
    HandleType
    haDevice :: ()
    haType :: Handle__ -> HandleType
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haOutputNL :: Handle__ -> Newline
    haInputNL :: Handle__ -> Newline
    haCodec :: Handle__ -> Maybe TextEncoding
    haDecoder :: ()
    haEncoder :: ()
    haBuffers :: Handle__ -> IORef (BufferList CharBufElem)
    haCharBuffer :: Handle__ -> IORef (Buffer CharBufElem)
    haLastDecode :: ()
    haBufferMode :: Handle__ -> BufferMode
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haDevice :: dev
    haType :: HandleType
    haByteBuffer :: IORef (Buffer Word8)
    haBufferMode :: BufferMode
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haCharBuffer :: IORef (Buffer CharBufElem)
    haBuffers :: IORef (BufferList CharBufElem)
    haEncoder :: Maybe (TextEncoder enc_state)
    haDecoder :: Maybe (TextDecoder dec_state)
    haCodec :: Maybe TextEncoding
    haInputNL :: Newline
    haOutputNL :: Newline
    haOtherSide :: Maybe (MVar Handle__)
    ..} -> do

          -- TODO: Guard these on Windows
          posn <- if IoSubSystem
    ioSubSystem IoSubSystem -> IoSubSystem -> Bool
    forall a. Eq a => a -> a -> Bool
    == IoSubSystem
    IoNative
                             then (Word64 -> Integer
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral (Word64 -> Integer)
    -> (Buffer Word8 -> Word64) -> Buffer Word8 -> Integer
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Buffer Word8 -> Word64
    forall e. Buffer e -> Word64
    bufOffset) (Buffer Word8 -> Integer) -> IO (Buffer Word8) -> IO Integer
    forall a b. (a -> b) -> IO a -> IO b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    `fmap` IORef (Buffer Word8) -> IO (Buffer Word8)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Word8)
    haByteBuffer
                             else dev -> IO Integer
    forall a. IODevice a => a -> IO Integer
    IODevice.tell dev
    haDevice

          -- we can't tell the real byte offset if there are buffered
          -- Chars, so must flush first:
          flushCharBuffer handle_

          bbuf <- readIORef haByteBuffer
          debugIO ("hTell bbuf (elems=" ++ show (bufferElems bbuf) ++ ")"
                   ++ summaryBuffer bbuf)

          let real_posn
               | Buffer Word8 -> Bool
    forall e. Buffer e -> Bool
    isWriteBuffer Buffer Word8
    bbuf = Integer
    posn Integer -> Integer -> Integer
    forall a. Num a => a -> a -> a
    + Int -> Integer
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral (Buffer Word8 -> Int
    forall e. Buffer e -> Int
    bufferElems Buffer Word8
    bbuf)
               | Bool
    otherwise          = Integer
    posn Integer -> Integer -> Integer
    forall a. Num a => a -> a -> a
    - Int -> Integer
    forall a b. (Integral a, Num b) => a -> b
    fromIntegral (Buffer Word8 -> Int
    forall e. Buffer e -> Int
    bufferElems Buffer Word8
    bbuf)

          cbuf <- readIORef haCharBuffer
          debugIO ("\nhGetPosn: (posn, real_posn) = " ++ show (posn, real_posn))
          debugIO ("   cbuf: " ++ summaryBuffer cbuf ++
                   "   bbuf: " ++ summaryBuffer bbuf)

          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' hdl@ returns whether the handle is open.
    -- If the 'haType' of @hdl@ is 'ClosedHandle' or 'SemiClosedHandle' this returns 'False'
    -- and 'True' otherwise.
    hIsOpen :: Handle -> IO Bool
    hIsOpen :: Handle -> IO Bool
    hIsOpen Handle
    handle =
        String -> Handle -> (Handle__ -> IO Bool) -> IO Bool
    forall a. String -> Handle -> (Handle__ -> IO a) -> IO a
    withHandle_ String
    "hIsOpen" Handle
    handle ((Handle__ -> IO Bool) -> IO Bool)
    -> (Handle__ -> IO Bool) -> IO Bool
    forall a b. (a -> b) -> a -> b
    $ \ Handle__
    handle_ -> do
        case Handle__ -> HandleType
    haType Handle__
    handle_ of
          HandleType
    ClosedHandle         -> Bool -> IO Bool
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Bool
    False
          HandleType
    SemiClosedHandle     -> Bool -> IO Bool
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Bool
    False
          HandleType
    _                    -> Bool -> IO Bool
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Bool
    True

    -- | @'hIsOpen' hdl@ returns whether the handle is closed.
    -- If the 'haType' of @hdl@ is 'ClosedHandle' this returns 'True'
    -- and 'False' otherwise.
    hIsClosed :: Handle -> IO Bool
    hIsClosed :: Handle -> IO Bool
    hIsClosed Handle
    handle =
        String -> Handle -> (Handle__ -> IO Bool) -> IO Bool
    forall a. String -> Handle -> (Handle__ -> IO a) -> IO a
    withHandle_ String
    "hIsClosed" Handle
    handle ((Handle__ -> IO Bool) -> IO Bool)
    -> (Handle__ -> IO Bool) -> IO Bool
    forall a b. (a -> b) -> a -> b
    $ \ Handle__
    handle_ -> do
        case Handle__ -> HandleType
    haType Handle__
    handle_ of
          HandleType
    ClosedHandle         -> Bool -> IO Bool
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Bool
    True
          HandleType
    _                    -> Bool -> IO Bool
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Bool
    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' hdl@ returns whether it is possible to read from the handle.
    hIsReadable :: Handle -> IO Bool
    hIsReadable :: Handle -> IO Bool
    hIsReadable (DuplexHandle String
    _ MVar Handle__
    _ MVar Handle__
    _) = Bool -> IO Bool
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Bool
    True
    hIsReadable Handle
    handle =
        String -> Handle -> (Handle__ -> IO Bool) -> IO Bool
    forall a. String -> Handle -> (Handle__ -> IO a) -> IO a
    withHandle_ String
    "hIsReadable" Handle
    handle ((Handle__ -> IO Bool) -> IO Bool)
    -> (Handle__ -> IO Bool) -> IO Bool
    forall a b. (a -> b) -> a -> b
    $ \ Handle__
    handle_ -> do
        case Handle__ -> HandleType
    haType Handle__
    handle_ of
          HandleType
    ClosedHandle         -> IO Bool
    forall a. IO a
    ioe_closedHandle
          HandleType
    SemiClosedHandle     -> IO Bool
    forall a. IO a
    ioe_semiclosedHandle
          HandleType
    htype                -> Bool -> IO Bool
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return (HandleType -> Bool
    isReadableHandleType HandleType
    htype)

    -- | @'hIsWritable' hdl@ returns whether it is possible to write to the handle.
    hIsWritable :: Handle -> IO Bool
    hIsWritable :: Handle -> IO Bool
    hIsWritable (DuplexHandle String
    _ MVar Handle__
    _ MVar Handle__
    _) = Bool -> IO Bool
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Bool
    True
    hIsWritable Handle
    handle =
        String -> Handle -> (Handle__ -> IO Bool) -> IO Bool
    forall a. String -> Handle -> (Handle__ -> IO a) -> IO a
    withHandle_ String
    "hIsWritable" Handle
    handle ((Handle__ -> IO Bool) -> IO Bool)
    -> (Handle__ -> IO Bool) -> IO Bool
    forall a b. (a -> b) -> a -> b
    $ \ Handle__
    handle_ -> do
        case Handle__ -> HandleType
    haType Handle__
    handle_ of
          HandleType
    ClosedHandle         -> IO Bool
    forall a. IO a
    ioe_closedHandle
          HandleType
    SemiClosedHandle     -> IO Bool
    forall a. IO a
    ioe_semiclosedHandle
          HandleType
    htype                -> Bool -> IO Bool
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return (HandleType -> Bool
    isWritableHandleType HandleType
    htype)

    -- | Computation 'hGetBuffering' @hdl@ returns the current buffering mode
    -- for @hdl@.

    hGetBuffering :: Handle -> IO BufferMode
    hGetBuffering :: Handle -> IO BufferMode
    hGetBuffering Handle
    handle =
        String -> Handle -> (Handle__ -> IO BufferMode) -> IO BufferMode
    forall a. String -> Handle -> (Handle__ -> IO a) -> IO a
    withHandle_ String
    "hGetBuffering" Handle
    handle ((Handle__ -> IO BufferMode) -> IO BufferMode)
    -> (Handle__ -> IO BufferMode) -> IO BufferMode
    forall a b. (a -> b) -> a -> b
    $ \ Handle__
    handle_ -> do
        case Handle__ -> HandleType
    haType Handle__
    handle_ of
          HandleType
    ClosedHandle         -> IO BufferMode
    forall a. IO a
    ioe_closedHandle
          HandleType
    _ ->
               -- We're being non-standard here, and allow the buffering
               -- of a semi-closed handle to be queried.   -- sof 6/98
              BufferMode -> IO BufferMode
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Handle__ -> BufferMode
    haBufferMode Handle__
    handle_)  -- could be stricter..

    -- | @'hIsSeekable' hdl@ returns whether it is possible to 'hSeek' with the given handle.
    hIsSeekable :: Handle -> IO Bool
    hIsSeekable :: Handle -> IO Bool
    hIsSeekable Handle
    handle =
        String -> Handle -> (Handle__ -> IO Bool) -> IO Bool
    forall a. String -> Handle -> (Handle__ -> IO a) -> IO a
    withHandle_ String
    "hIsSeekable" Handle
    handle ((Handle__ -> IO Bool) -> IO Bool)
    -> (Handle__ -> IO Bool) -> IO Bool
    forall a b. (a -> b) -> a -> b
    $ \ handle_ :: Handle__
    handle_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe TextEncoding
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    IORef (dec_state, Buffer Word8)
    IORef (Buffer CharBufElem)
    IORef (Buffer Word8)
    IORef (BufferList CharBufElem)
    Newline
    BufferMode
    HandleType
    haDevice :: ()
    haType :: Handle__ -> HandleType
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haOutputNL :: Handle__ -> Newline
    haInputNL :: Handle__ -> Newline
    haCodec :: Handle__ -> Maybe TextEncoding
    haDecoder :: ()
    haEncoder :: ()
    haBuffers :: Handle__ -> IORef (BufferList CharBufElem)
    haCharBuffer :: Handle__ -> IORef (Buffer CharBufElem)
    haLastDecode :: ()
    haBufferMode :: Handle__ -> BufferMode
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haDevice :: dev
    haType :: HandleType
    haByteBuffer :: IORef (Buffer Word8)
    haBufferMode :: BufferMode
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haCharBuffer :: IORef (Buffer CharBufElem)
    haBuffers :: IORef (BufferList CharBufElem)
    haEncoder :: Maybe (TextEncoder enc_state)
    haDecoder :: Maybe (TextDecoder dec_state)
    haCodec :: Maybe TextEncoding
    haInputNL :: Newline
    haOutputNL :: Newline
    haOtherSide :: Maybe (MVar Handle__)
    ..} -> do
        case HandleType
    haType of
          HandleType
    ClosedHandle         -> IO Bool
    forall a. IO a
    ioe_closedHandle
          HandleType
    SemiClosedHandle     -> IO Bool
    forall a. IO a
    ioe_semiclosedHandle
          HandleType
    AppendHandle         -> Bool -> IO Bool
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Bool
    False
          HandleType
    _                    -> dev -> IO Bool
    forall a. IODevice a => a -> IO Bool
    IODevice.isSeekable dev
    haDevice

    -- -----------------------------------------------------------------------------
    -- Changing echo status

    -- | Set the echoing status of a handle connected to a terminal.

    hSetEcho :: Handle -> Bool -> IO ()
    hSetEcho :: Handle -> Bool -> IO ()
    hSetEcho Handle
    handle Bool
    on = do
        isT   <- Handle -> IO Bool
    hIsTerminalDevice Handle
    handle
        if not isT
         then return ()
         else
          withHandle_ "hSetEcho" handle $ \ Handle__{dev
    Maybe (MVar Handle__)
    Maybe TextEncoding
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    IORef (dec_state, Buffer Word8)
    IORef (Buffer CharBufElem)
    IORef (Buffer Word8)
    IORef (BufferList CharBufElem)
    Newline
    BufferMode
    HandleType
    haDevice :: ()
    haType :: Handle__ -> HandleType
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haOutputNL :: Handle__ -> Newline
    haInputNL :: Handle__ -> Newline
    haCodec :: Handle__ -> Maybe TextEncoding
    haDecoder :: ()
    haEncoder :: ()
    haBuffers :: Handle__ -> IORef (BufferList CharBufElem)
    haCharBuffer :: Handle__ -> IORef (Buffer CharBufElem)
    haLastDecode :: ()
    haBufferMode :: Handle__ -> BufferMode
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haDevice :: dev
    haType :: HandleType
    haByteBuffer :: IORef (Buffer Word8)
    haBufferMode :: BufferMode
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haCharBuffer :: IORef (Buffer CharBufElem)
    haBuffers :: IORef (BufferList CharBufElem)
    haEncoder :: Maybe (TextEncoder enc_state)
    haDecoder :: Maybe (TextDecoder dec_state)
    haCodec :: Maybe TextEncoding
    haInputNL :: Newline
    haOutputNL :: Newline
    haOtherSide :: Maybe (MVar Handle__)
    ..} -> do
          case HandleType
    haType of
             HandleType
    ClosedHandle -> IO ()
    forall a. IO a
    ioe_closedHandle
             HandleType
    _            -> dev -> Bool -> IO ()
    forall a. IODevice a => a -> Bool -> IO ()
    IODevice.setEcho dev
    haDevice Bool
    on

    -- | Get the echoing status of a handle connected to a terminal.

    hGetEcho :: Handle -> IO Bool
    hGetEcho :: Handle -> IO Bool
    hGetEcho Handle
    handle = do
        isT   <- Handle -> IO Bool
    hIsTerminalDevice Handle
    handle
        if not isT
         then return False
         else
           withHandle_ "hGetEcho" handle $ \ Handle__{dev
    Maybe (MVar Handle__)
    Maybe TextEncoding
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    IORef (dec_state, Buffer Word8)
    IORef (Buffer CharBufElem)
    IORef (Buffer Word8)
    IORef (BufferList CharBufElem)
    Newline
    BufferMode
    HandleType
    haDevice :: ()
    haType :: Handle__ -> HandleType
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haOutputNL :: Handle__ -> Newline
    haInputNL :: Handle__ -> Newline
    haCodec :: Handle__ -> Maybe TextEncoding
    haDecoder :: ()
    haEncoder :: ()
    haBuffers :: Handle__ -> IORef (BufferList CharBufElem)
    haCharBuffer :: Handle__ -> IORef (Buffer CharBufElem)
    haLastDecode :: ()
    haBufferMode :: Handle__ -> BufferMode
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haDevice :: dev
    haType :: HandleType
    haByteBuffer :: IORef (Buffer Word8)
    haBufferMode :: BufferMode
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haCharBuffer :: IORef (Buffer CharBufElem)
    haBuffers :: IORef (BufferList CharBufElem)
    haEncoder :: Maybe (TextEncoder enc_state)
    haDecoder :: Maybe (TextDecoder dec_state)
    haCodec :: Maybe TextEncoding
    haInputNL :: Newline
    haOutputNL :: Newline
    haOtherSide :: Maybe (MVar Handle__)
    ..} -> do
           case HandleType
    haType of
             HandleType
    ClosedHandle -> IO Bool
    forall a. IO a
    ioe_closedHandle
             HandleType
    _            -> dev -> IO Bool
    forall a. IODevice a => a -> IO Bool
    IODevice.getEcho dev
    haDevice

    -- | Is the handle connected to a terminal?
    --
    -- On Windows the result of 'hIsTerminalDevide' might be misleading,
    -- because non-native terminals, such as MinTTY used in MSYS and Cygwin environments,
    -- are implemented via redirection.
    -- Use @System.Win32.Types.withHandleToHANDLE System.Win32.MinTTY.isMinTTYHandle@
    -- to recognise it. Also consider @ansi-terminal@ package for crossplatform terminal
    -- support.
    --
    hIsTerminalDevice :: Handle -> IO Bool
    hIsTerminalDevice :: Handle -> IO Bool
    hIsTerminalDevice Handle
    handle =
        String -> Handle -> (Handle__ -> IO Bool) -> IO Bool
    forall a. String -> Handle -> (Handle__ -> IO a) -> IO a
    withHandle_ String
    "hIsTerminalDevice" Handle
    handle ((Handle__ -> IO Bool) -> IO Bool)
    -> (Handle__ -> IO Bool) -> IO Bool
    forall a b. (a -> b) -> a -> b
    $ \ Handle__{dev
    Maybe (MVar Handle__)
    Maybe TextEncoding
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    IORef (dec_state, Buffer Word8)
    IORef (Buffer CharBufElem)
    IORef (Buffer Word8)
    IORef (BufferList CharBufElem)
    Newline
    BufferMode
    HandleType
    haDevice :: ()
    haType :: Handle__ -> HandleType
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haOutputNL :: Handle__ -> Newline
    haInputNL :: Handle__ -> Newline
    haCodec :: Handle__ -> Maybe TextEncoding
    haDecoder :: ()
    haEncoder :: ()
    haBuffers :: Handle__ -> IORef (BufferList CharBufElem)
    haCharBuffer :: Handle__ -> IORef (Buffer CharBufElem)
    haLastDecode :: ()
    haBufferMode :: Handle__ -> BufferMode
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haDevice :: dev
    haType :: HandleType
    haByteBuffer :: IORef (Buffer Word8)
    haBufferMode :: BufferMode
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haCharBuffer :: IORef (Buffer CharBufElem)
    haBuffers :: IORef (BufferList CharBufElem)
    haEncoder :: Maybe (TextEncoder enc_state)
    haDecoder :: Maybe (TextDecoder dec_state)
    haCodec :: Maybe TextEncoding
    haInputNL :: Newline
    haOutputNL :: Newline
    haOtherSide :: Maybe (MVar Handle__)
    ..} -> do
         case HandleType
    haType of
           HandleType
    ClosedHandle -> IO Bool
    forall a. IO a
    ioe_closedHandle
           HandleType
    _            -> dev -> IO Bool
    forall a. IODevice a => a -> IO Bool
    IODevice.isTerminal dev
    haDevice

    -- -----------------------------------------------------------------------------
    -- hSetBinaryMode

    -- | 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'.
    --
    hSetBinaryMode :: Handle -> Bool -> IO ()
    hSetBinaryMode :: Handle -> Bool -> IO ()
    hSetBinaryMode Handle
    handle Bool
    bin =
      String -> Handle -> (Handle__ -> IO Handle__) -> IO ()
    withAllHandles__ String
    "hSetBinaryMode" Handle
    handle ((Handle__ -> IO Handle__) -> IO ())
    -> (Handle__ -> IO Handle__) -> IO ()
    forall a b. (a -> b) -> a -> b
    $ \ h_ :: Handle__
    h_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe TextEncoding
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    IORef (dec_state, Buffer Word8)
    IORef (Buffer CharBufElem)
    IORef (Buffer Word8)
    IORef (BufferList CharBufElem)
    Newline
    BufferMode
    HandleType
    haDevice :: ()
    haType :: Handle__ -> HandleType
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haOutputNL :: Handle__ -> Newline
    haInputNL :: Handle__ -> Newline
    haCodec :: Handle__ -> Maybe TextEncoding
    haDecoder :: ()
    haEncoder :: ()
    haBuffers :: Handle__ -> IORef (BufferList CharBufElem)
    haCharBuffer :: Handle__ -> IORef (Buffer CharBufElem)
    haLastDecode :: ()
    haBufferMode :: Handle__ -> BufferMode
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haDevice :: dev
    haType :: HandleType
    haByteBuffer :: IORef (Buffer Word8)
    haBufferMode :: BufferMode
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haCharBuffer :: IORef (Buffer CharBufElem)
    haBuffers :: IORef (BufferList CharBufElem)
    haEncoder :: Maybe (TextEncoder enc_state)
    haDecoder :: Maybe (TextDecoder dec_state)
    haCodec :: Maybe TextEncoding
    haInputNL :: Newline
    haOutputNL :: Newline
    haOtherSide :: Maybe (MVar Handle__)
    ..} ->
        do
             Handle__ -> IO ()
    flushCharBuffer Handle__
    h_
             Handle__ -> IO ()
    closeTextCodecs Handle__
    h_

             mb_te <- if Bool
    bin then Maybe TextEncoding -> IO (Maybe TextEncoding)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Maybe TextEncoding
    forall a. Maybe a
    Nothing
                             else (TextEncoding -> Maybe TextEncoding)
    -> IO TextEncoding -> IO (Maybe TextEncoding)
    forall a b. (a -> b) -> IO a -> IO b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap TextEncoding -> Maybe TextEncoding
    forall a. a -> Maybe a
    Just IO TextEncoding
    getLocaleEncoding

             openTextEncoding mb_te haType $ \ Maybe (TextEncoder es)
    mb_encoder Maybe (TextDecoder ds)
    mb_decoder -> do

             -- should match the default newline mode, whatever that is
             let nl :: NewlineMode
    nl    | Bool
    bin       = NewlineMode
    noNewlineTranslation
                       | Bool
    otherwise = NewlineMode
    nativeNewlineMode

             bbuf <- IORef (Buffer Word8) -> IO (Buffer Word8)
    forall a. IORef a -> IO a
    readIORef IORef (Buffer Word8)
    haByteBuffer
             ref <- newIORef (errorWithoutStackTrace "codec_state", bbuf)

             return Handle__{ haLastDecode = ref,
                              haEncoder  = mb_encoder,
                              haDecoder  = mb_decoder,
                              haCodec    = mb_te,
                              haInputNL  = inputNL nl,
                              haOutputNL = outputNL nl, .. }

    -- -----------------------------------------------------------------------------
    -- hSetNewlineMode

    -- | Set the 'NewlineMode' on the specified 'Handle'.  All buffered
    -- data is flushed first.
    hSetNewlineMode :: Handle -> NewlineMode -> IO ()
    hSetNewlineMode :: Handle -> NewlineMode -> IO ()
    hSetNewlineMode Handle
    handle NewlineMode{ inputNL :: NewlineMode -> Newline
    inputNL=Newline
    i, outputNL :: NewlineMode -> Newline
    outputNL=Newline
    o } =
      String -> Handle -> (Handle__ -> IO Handle__) -> IO ()
    withAllHandles__ String
    "hSetNewlineMode" Handle
    handle ((Handle__ -> IO Handle__) -> IO ())
    -> (Handle__ -> IO Handle__) -> IO ()
    forall a b. (a -> b) -> a -> b
    $ \h_ :: Handle__
    h_@Handle__{} ->
        do
             Handle__ -> IO ()
    flushBuffer Handle__
    h_
             Handle__ -> IO Handle__
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Handle__
    h_{ haInputNL=i, haOutputNL=o }

    -- -----------------------------------------------------------------------------
    -- Duplicating a Handle

    -- | Returns a duplicate of the original handle, with its own buffer.
    -- The two Handles will share a file pointer, however.  The original
    -- handle's buffer is flushed, including discarding any input data,
    -- before the handle is duplicated.

    hDuplicate :: Handle -> IO Handle
    hDuplicate :: Handle -> IO Handle
    hDuplicate h :: Handle
    h@(FileHandle String
    path MVar Handle__
    m) =
      String
    -> Handle -> MVar Handle__ -> (Handle__ -> IO Handle) -> IO Handle
    forall a.
    String -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    withHandle_' String
    "hDuplicate" Handle
    h MVar Handle__
    m ((Handle__ -> IO Handle) -> IO Handle)
    -> (Handle__ -> IO Handle) -> IO Handle
    forall a b. (a -> b) -> a -> b
    $ \Handle__
    h_ ->
          String
    -> Handle
    -> Maybe (MVar Handle__)
    -> Handle__
    -> Maybe HandleFinalizer
    -> IO Handle
    dupHandle String
    path Handle
    h Maybe (MVar Handle__)
    forall a. Maybe a
    Nothing Handle__
    h_ (HandleFinalizer -> Maybe HandleFinalizer
    forall a. a -> Maybe a
    Just HandleFinalizer
    handleFinalizer)
    hDuplicate h :: Handle
    h@(DuplexHandle String
    path MVar Handle__
    r MVar Handle__
    w) = do
      write_side@(FileHandle _ write_m) <-
         String
    -> Handle -> MVar Handle__ -> (Handle__ -> IO Handle) -> IO Handle
    forall a.
    String -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    withHandle_' String
    "hDuplicate" Handle
    h MVar Handle__
    w ((Handle__ -> IO Handle) -> IO Handle)
    -> (Handle__ -> IO Handle) -> IO Handle
    forall a b. (a -> b) -> a -> b
    $ \Handle__
    h_ ->
            String
    -> Handle
    -> Maybe (MVar Handle__)
    -> Handle__
    -> Maybe HandleFinalizer
    -> IO Handle
    dupHandle String
    path Handle
    h Maybe (MVar Handle__)
    forall a. Maybe a
    Nothing Handle__
    h_ (HandleFinalizer -> Maybe HandleFinalizer
    forall a. a -> Maybe a
    Just HandleFinalizer
    handleFinalizer)
      read_side@(FileHandle _ read_m) <-
        withHandle_' "hDuplicate" h r $ \Handle__
    h_ ->
            String
    -> Handle
    -> Maybe (MVar Handle__)
    -> Handle__
    -> Maybe HandleFinalizer
    -> IO Handle
    dupHandle String
    path Handle
    h (MVar Handle__ -> Maybe (MVar Handle__)
    forall a. a -> Maybe a
    Just MVar Handle__
    write_m) Handle__
    h_  Maybe HandleFinalizer
    forall a. Maybe a
    Nothing
      return (DuplexHandle path read_m write_m)

    dupHandle :: FilePath
              -> Handle
              -> Maybe (MVar Handle__)
              -> Handle__
              -> Maybe HandleFinalizer
              -> IO Handle
    dupHandle :: String
    -> Handle
    -> Maybe (MVar Handle__)
    -> Handle__
    -> Maybe HandleFinalizer
    -> IO Handle
    dupHandle String
    filepath Handle
    h Maybe (MVar Handle__)
    other_side h_ :: Handle__
    h_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe TextEncoding
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    IORef (dec_state, Buffer Word8)
    IORef (Buffer CharBufElem)
    IORef (Buffer Word8)
    IORef (BufferList CharBufElem)
    Newline
    BufferMode
    HandleType
    haDevice :: ()
    haType :: Handle__ -> HandleType
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haOutputNL :: Handle__ -> Newline
    haInputNL :: Handle__ -> Newline
    haCodec :: Handle__ -> Maybe TextEncoding
    haDecoder :: ()
    haEncoder :: ()
    haBuffers :: Handle__ -> IORef (BufferList CharBufElem)
    haCharBuffer :: Handle__ -> IORef (Buffer CharBufElem)
    haLastDecode :: ()
    haBufferMode :: Handle__ -> BufferMode
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haDevice :: dev
    haType :: HandleType
    haByteBuffer :: IORef (Buffer Word8)
    haBufferMode :: BufferMode
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haCharBuffer :: IORef (Buffer CharBufElem)
    haBuffers :: IORef (BufferList CharBufElem)
    haEncoder :: Maybe (TextEncoder enc_state)
    haDecoder :: Maybe (TextDecoder dec_state)
    haCodec :: Maybe TextEncoding
    haInputNL :: Newline
    haOutputNL :: Newline
    haOtherSide :: Maybe (MVar Handle__)
    ..} Maybe HandleFinalizer
    mb_finalizer = do
      -- flush the buffer first, so we don't have to copy its contents
      Handle__ -> IO ()
    flushBuffer Handle__
    h_
      case Maybe (MVar Handle__)
    other_side of
        Maybe (MVar Handle__)
    Nothing -> do
           new_dev <- dev -> IO dev
    forall a. IODevice a => a -> IO a
    IODevice.dup dev
    haDevice
           dupHandle_ new_dev filepath other_side h_ mb_finalizer
        Just MVar Handle__
    r  ->
           String
    -> Handle -> MVar Handle__ -> (Handle__ -> IO Handle) -> IO Handle
    forall a.
    String -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    withHandle_' String
    "dupHandle" Handle
    h MVar Handle__
    r ((Handle__ -> IO Handle) -> IO Handle)
    -> (Handle__ -> IO Handle) -> IO Handle
    forall a b. (a -> b) -> a -> b
    $ \Handle__{haDevice :: ()
    haDevice=dev
    dev} ->
             dev
    -> String
    -> Maybe (MVar Handle__)
    -> Handle__
    -> Maybe HandleFinalizer
    -> IO Handle
    forall dev.
    (RawIO dev, IODevice dev, BufferedIO dev, Typeable dev) =>
    dev
    -> String
    -> Maybe (MVar Handle__)
    -> Handle__
    -> Maybe HandleFinalizer
    -> IO Handle
    dupHandle_ dev
    dev String
    filepath Maybe (MVar Handle__)
    other_side Handle__
    h_ Maybe HandleFinalizer
    mb_finalizer

    dupHandle_ :: (RawIO dev, IODevice dev, BufferedIO dev, Typeable dev) => dev
               -> FilePath
               -> Maybe (MVar Handle__)
               -> Handle__
               -> Maybe HandleFinalizer
               -> IO Handle
    dupHandle_ :: forall dev.
    (RawIO dev, IODevice dev, BufferedIO dev, Typeable dev) =>
    dev
    -> String
    -> Maybe (MVar Handle__)
    -> Handle__
    -> Maybe HandleFinalizer
    -> IO Handle
    dupHandle_ dev
    new_dev String
    filepath Maybe (MVar Handle__)
    other_side h_ :: Handle__
    h_@Handle__{dev
    Maybe (MVar Handle__)
    Maybe TextEncoding
    Maybe (TextEncoder enc_state)
    Maybe (TextDecoder dec_state)
    IORef (dec_state, Buffer Word8)
    IORef (Buffer CharBufElem)
    IORef (Buffer Word8)
    IORef (BufferList CharBufElem)
    Newline
    BufferMode
    HandleType
    haDevice :: ()
    haType :: Handle__ -> HandleType
    haOtherSide :: Handle__ -> Maybe (MVar Handle__)
    haOutputNL :: Handle__ -> Newline
    haInputNL :: Handle__ -> Newline
    haCodec :: Handle__ -> Maybe TextEncoding
    haDecoder :: ()
    haEncoder :: ()
    haBuffers :: Handle__ -> IORef (BufferList CharBufElem)
    haCharBuffer :: Handle__ -> IORef (Buffer CharBufElem)
    haLastDecode :: ()
    haBufferMode :: Handle__ -> BufferMode
    haByteBuffer :: Handle__ -> IORef (Buffer Word8)
    haDevice :: dev
    haType :: HandleType
    haByteBuffer :: IORef (Buffer Word8)
    haBufferMode :: BufferMode
    haLastDecode :: IORef (dec_state, Buffer Word8)
    haCharBuffer :: IORef (Buffer CharBufElem)
    haBuffers :: IORef (BufferList CharBufElem)
    haEncoder :: Maybe (TextEncoder enc_state)
    haDecoder :: Maybe (TextDecoder dec_state)
    haCodec :: Maybe TextEncoding
    haInputNL :: Newline
    haOutputNL :: Newline
    haOtherSide :: Maybe (MVar Handle__)
    ..} Maybe HandleFinalizer
    mb_finalizer = do
       -- XXX wrong!
      mb_codec <- if Maybe (TextEncoder enc_state) -> Bool
    forall a. Maybe a -> Bool
    isJust Maybe (TextEncoder enc_state)
    haEncoder then (TextEncoding -> Maybe TextEncoding)
    -> IO TextEncoding -> IO (Maybe TextEncoding)
    forall a b. (a -> b) -> IO a -> IO b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap TextEncoding -> Maybe TextEncoding
    forall a. a -> Maybe a
    Just IO TextEncoding
    getLocaleEncoding else Maybe TextEncoding -> IO (Maybe TextEncoding)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Maybe TextEncoding
    forall a. Maybe a
    Nothing
      mkHandle new_dev filepath haType True{-buffered-} mb_codec
          NewlineMode { inputNL = haInputNL, outputNL = haOutputNL }
          mb_finalizer other_side

    -- -----------------------------------------------------------------------------
    -- 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 :: Handle -> Handle -> IO ()
    hDuplicateTo h1 :: Handle
    h1@(FileHandle String
    path MVar Handle__
    m1) h2 :: Handle
    h2@(FileHandle String
    _ MVar Handle__
    m2) =
     String
    -> Handle -> MVar Handle__ -> (Handle__ -> IO Handle__) -> IO ()
    withHandle__' String
    "hDuplicateTo" Handle
    h2 MVar Handle__
    m2 ((Handle__ -> IO Handle__) -> IO ())
    -> (Handle__ -> IO Handle__) -> IO ()
    forall a b. (a -> b) -> a -> b
    $ \Handle__
    h2_ -> do
       IO () -> IO ()
    try (IO () -> IO ()) -> IO () -> IO ()
    forall a b. (a -> b) -> a -> b
    $ Handle__ -> IO ()
    flushWriteBuffer Handle__
    h2_
       String
    -> Handle
    -> MVar Handle__
    -> (Handle__ -> IO Handle__)
    -> IO Handle__
    forall a.
    String -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    withHandle_' String
    "hDuplicateTo" Handle
    h1 MVar Handle__
    m1 ((Handle__ -> IO Handle__) -> IO Handle__)
    -> (Handle__ -> IO Handle__) -> IO Handle__
    forall a b. (a -> b) -> a -> b
    $ \Handle__
    h1_ ->
         String
    -> Handle
    -> Maybe (MVar Handle__)
    -> Handle__
    -> Handle__
    -> Maybe HandleFinalizer
    -> IO Handle__
    dupHandleTo String
    path Handle
    h1 Maybe (MVar Handle__)
    forall a. Maybe a
    Nothing Handle__
    h2_ Handle__
    h1_ (HandleFinalizer -> Maybe HandleFinalizer
    forall a. a -> Maybe a
    Just HandleFinalizer
    handleFinalizer)
    hDuplicateTo h1 :: Handle
    h1@(DuplexHandle String
    path MVar Handle__
    r1 MVar Handle__
    w1) h2 :: Handle
    h2@(DuplexHandle String
    _ MVar Handle__
    r2 MVar Handle__
    w2)  = do
     String
    -> Handle -> MVar Handle__ -> (Handle__ -> IO Handle__) -> IO ()
    withHandle__' String
    "hDuplicateTo" Handle
    h2 MVar Handle__
    w2  ((Handle__ -> IO Handle__) -> IO ())
    -> (Handle__ -> IO Handle__) -> IO ()
    forall a b. (a -> b) -> a -> b
    $ \Handle__
    w2_ -> do
       IO () -> IO ()
    try (IO () -> IO ()) -> IO () -> IO ()
    forall a b. (a -> b) -> a -> b
    $ Handle__ -> IO ()
    flushWriteBuffer Handle__
    w2_
       String
    -> Handle
    -> MVar Handle__
    -> (Handle__ -> IO Handle__)
    -> IO Handle__
    forall a.
    String -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    withHandle_' String
    "hDuplicateTo" Handle
    h1 MVar Handle__
    w1 ((Handle__ -> IO Handle__) -> IO Handle__)
    -> (Handle__ -> IO Handle__) -> IO Handle__
    forall a b. (a -> b) -> a -> b
    $ \Handle__
    w1_ ->
         String
    -> Handle
    -> Maybe (MVar Handle__)
    -> Handle__
    -> Handle__
    -> Maybe HandleFinalizer
    -> IO Handle__
    dupHandleTo String
    path Handle
    h1 Maybe (MVar Handle__)
    forall a. Maybe a
    Nothing Handle__
    w2_ Handle__
    w1_ (HandleFinalizer -> Maybe HandleFinalizer
    forall a. a -> Maybe a
    Just HandleFinalizer
    handleFinalizer)
     String
    -> Handle -> MVar Handle__ -> (Handle__ -> IO Handle__) -> IO ()
    withHandle__' String
    "hDuplicateTo" Handle
    h2 MVar Handle__
    r2  ((Handle__ -> IO Handle__) -> IO ())
    -> (Handle__ -> IO Handle__) -> IO ()
    forall a b. (a -> b) -> a -> b
    $ \Handle__
    r2_ -> do
       IO () -> IO ()
    try (IO () -> IO ()) -> IO () -> IO ()
    forall a b. (a -> b) -> a -> b
    $ Handle__ -> IO ()
    flushWriteBuffer Handle__
    r2_
       String
    -> Handle
    -> MVar Handle__
    -> (Handle__ -> IO Handle__)
    -> IO Handle__
    forall a.
    String -> Handle -> MVar Handle__ -> (Handle__ -> IO a) -> IO a
    withHandle_' String
    "hDuplicateTo" Handle
    h1 MVar Handle__
    r1 ((Handle__ -> IO Handle__) -> IO Handle__)
    -> (Handle__ -> IO Handle__) -> IO Handle__
    forall a b. (a -> b) -> a -> b
    $ \Handle__
    r1_ ->
         String
    -> Handle
    -> Maybe (MVar Handle__)
    -> Handle__
    -> Handle__
    -> Maybe HandleFinalizer
    -> IO Handle__
    dupHandleTo String
    path Handle
    h1 (MVar Handle__ -> Maybe (MVar Handle__)
    forall a. a -> Maybe a
    Just MVar Handle__
    w1) Handle__
    r2_ Handle__
    r1_ Maybe HandleFinalizer
    forall a. Maybe a
    Nothing
    hDuplicateTo Handle
    h1 Handle
    _ =
      Handle -> IO ()
    forall a. Handle -> IO a
    ioe_dupHandlesNotCompatible Handle
    h1

    try :: IO () -> IO ()
    try :: IO () -> IO ()
    try IO ()
    io = IO ()
    io IO () -> (SomeException -> IO ()) -> IO ()
    forall e a. Exception e => IO a -> (e -> IO a) -> IO a
    `catchException` (IO () -> SomeException -> IO ()
    forall a b. a -> b -> a
    const (() -> IO ()
    forall a. a -> IO a
    forall (f :: * -> *) a. Applicative f => a -> f a
    pure ()) :: SomeException -> IO ())

    ioe_dupHandlesNotCompatible :: Handle -> IO a
    ioe_dupHandlesNotCompatible :: forall a. Handle -> IO a
    ioe_dupHandlesNotCompatible Handle
    h =
       IOException -> IO a
    forall a. HasCallStack => IOException -> IO a
    ioException (Maybe Handle
    -> IOErrorType
    -> String
    -> String
    -> Maybe CInt
    -> Maybe String
    -> IOException
    IOError (Handle -> Maybe Handle
    forall a. a -> Maybe a
    Just Handle
    h) IOErrorType
    IllegalOperation String
    "hDuplicateTo"
                    String
    "handles are incompatible" Maybe CInt
    forall a. Maybe a
    Nothing Maybe String
    forall a. Maybe a
    Nothing)

    dupHandleTo :: FilePath
                -> Handle
                -> Maybe (MVar Handle__)
                -> Handle__
                -> Handle__
                -> Maybe HandleFinalizer
                -> IO Handle__
    dupHandleTo :: String
    -> Handle
    -> Maybe (MVar Handle__)
    -> Handle__
    -> Handle__
    -> Maybe HandleFinalizer
    -> IO Handle__
    dupHandleTo String
    filepath Handle
    h Maybe (MVar Handle__)
    other_side
                hto_ :: Handle__
    hto_@Handle__{haDevice :: ()
    haDevice=dev
    devTo}
                h_ :: Handle__
    h_@Handle__{haDevice :: ()
    haDevice=dev
    dev} Maybe HandleFinalizer
    mb_finalizer = do
      Handle__ -> IO ()
    flushBuffer Handle__
    h_
      case dev -> Maybe dev
    forall a b. (Typeable a, Typeable b) => a -> Maybe b
    cast dev
    devTo of
        Maybe dev
    Nothing   -> Handle -> IO Handle__
    forall a. Handle -> IO a
    ioe_dupHandlesNotCompatible Handle
    h
        Just dev
    dev' -> do
          _ <- dev -> dev -> IO dev
    forall a. IODevice a => a -> a -> IO a
    IODevice.dup2 dev
    dev dev
    dev'
          FileHandle _ m <- dupHandle_ dev' filepath other_side h_ mb_finalizer
          takeMVar m

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

    hShow :: Handle -> IO String
    hShow :: Handle -> IO String
    hShow h :: Handle
    h@(FileHandle String
    path MVar Handle__
    _) = String -> Bool -> Handle -> IO String
    showHandle' String
    path Bool
    False Handle
    h
    hShow h :: Handle
    h@(DuplexHandle String
    path MVar Handle__
    _ MVar Handle__
    _) = String -> Bool -> Handle -> IO String
    showHandle' String
    path Bool
    True Handle
    h

    showHandle' :: String -> Bool -> Handle -> IO String
    showHandle' :: String -> Bool -> Handle -> IO String
    showHandle' String
    filepath Bool
    is_duplex Handle
    h =
      String -> Handle -> (Handle__ -> IO String) -> IO String
    forall a. String -> Handle -> (Handle__ -> IO a) -> IO a
    withHandle_ String
    "showHandle" Handle
    h ((Handle__ -> IO String) -> IO String)
    -> (Handle__ -> IO String) -> IO String
    forall a b. (a -> b) -> a -> b
    $ \Handle__
    hdl_ ->
        let
         showType :: String -> String
    showType | Bool
    is_duplex = String -> String -> String
    showString String
    "duplex (read-write)"
                  | Bool
    otherwise = HandleType -> String -> String
    forall a. Show a => a -> String -> String
    shows (Handle__ -> HandleType
    haType Handle__
    hdl_)
        in
        String -> IO String
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return
          (( CharBufElem -> String -> String
    showChar CharBufElem
    '{' (String -> String) -> (String -> String) -> String -> String
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    .
            HandleType -> (String -> String) -> String -> String
    showHdl (Handle__ -> HandleType
    haType Handle__
    hdl_)
                (String -> String -> String
    showString String
    "loc=" (String -> String) -> (String -> String) -> String -> String
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . String -> String -> String
    showString String
    filepath (String -> String) -> (String -> String) -> String -> String
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . CharBufElem -> String -> String
    showChar CharBufElem
    ',' (String -> String) -> (String -> String) -> String -> String
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    .
                 String -> String -> String
    showString String
    "type=" (String -> String) -> (String -> String) -> String -> String
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . String -> String
    showType (String -> String) -> (String -> String) -> String -> String
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . CharBufElem -> String -> String
    showChar CharBufElem
    ',' (String -> String) -> (String -> String) -> String -> String
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    .
                 String -> String -> String
    showString String
    "buffering=" (String -> String) -> (String -> String) -> String -> String
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Buffer CharBufElem -> BufferMode -> String -> String
    forall e. Buffer e -> BufferMode -> String -> String
    showBufMode (IO (Buffer CharBufElem) -> Buffer CharBufElem
    forall a. IO a -> a
    unsafePerformIO (IORef (Buffer CharBufElem) -> IO (Buffer CharBufElem)
    forall a. IORef a -> IO a
    readIORef (Handle__ -> IORef (Buffer CharBufElem)
    haCharBuffer Handle__
    hdl_))) (Handle__ -> BufferMode
    haBufferMode Handle__
    hdl_) (String -> String) -> (String -> String) -> String -> String
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . String -> String -> String
    showString String
    "}" )
          ) String
    "")
       where

        showHdl :: HandleType -> ShowS -> ShowS
        showHdl :: HandleType -> (String -> String) -> String -> String
    showHdl HandleType
    ht String -> String
    cont =
           case HandleType
    ht of
            HandleType
    ClosedHandle  -> HandleType -> String -> String
    forall a. Show a => a -> String -> String
    shows HandleType
    ht (String -> String) -> (String -> String) -> String -> String
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . String -> String -> String
    showString String
    "}"
            HandleType
    _ -> String -> String
    cont

        showBufMode :: Buffer e -> BufferMode -> ShowS
        showBufMode :: forall e. Buffer e -> BufferMode -> String -> String
    showBufMode Buffer e
    buf BufferMode
    bmo =
          case BufferMode
    bmo of
            BufferMode
    NoBuffering   -> String -> String -> String
    showString String
    "none"
            BufferMode
    LineBuffering -> String -> String -> String
    showString String
    "line"
            BlockBuffering (Just Int
    n) -> String -> String -> String
    showString String
    "block " (String -> String) -> (String -> String) -> String -> String
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Bool -> (String -> String) -> String -> String
    showParen Bool
    True (Int -> String -> String
    forall a. Show a => a -> String -> String
    shows Int
    n)
            BlockBuffering Maybe Int
    Nothing  -> String -> String -> String
    showString String
    "block " (String -> String) -> (String -> String) -> String -> String
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Bool -> (String -> String) -> String -> String
    showParen Bool
    True (Int -> String -> String
    forall a. Show a => a -> String -> String
    shows Int
    def)
          where
           def :: Int
           def :: Int
    def = Buffer e -> Int
    forall e. Buffer e -> Int
    bufSize Buffer e
    buf