{-# 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 (BufferCodec CharBufElem Word8 es)
    -> Maybe (BufferCodec Word8 CharBufElem 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 (BufferCodec CharBufElem Word8 es)
  -> Maybe (BufferCodec Word8 CharBufElem ds) -> IO Handle__)
 -> IO Handle__)
-> (forall es ds.
    Maybe (BufferCodec CharBufElem Word8 es)
    -> Maybe (BufferCodec Word8 CharBufElem 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 :: 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

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 :: 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 :: 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 :: 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