X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=System%2FIO.hs;h=bf26835eef628b0335ae9246723e0852295577aa;hb=HEAD;hp=ed75bb0b49e7ccbcd42f3eb8fdf92d96bcf3aab5;hpb=89bff9f249879a67baedc32d5e3f33771dfc64cd;p=ghc-base.git diff --git a/System/IO.hs b/System/IO.hs index ed75bb0..bf26835 100644 --- a/System/IO.hs +++ b/System/IO.hs @@ -1,4 +1,5 @@ -{-# OPTIONS_GHC -XNoImplicitPrelude #-} +{-# LANGUAGE CPP, NoImplicitPrelude #-} + ----------------------------------------------------------------------------- -- | -- Module : System.IO @@ -25,6 +26,15 @@ module System.IO ( Handle, -- abstract, instance of: Eq, Show. + -- | GHC note: a 'Handle' will be automatically closed when the garbage + -- collector detects that it has become unreferenced by the program. + -- However, relying on this behaviour is not generally recommended: + -- the garbage collector is unpredictable. If possible, use + -- an explicit 'hClose' to close 'Handle's when they are no longer + -- required. GHC does not currently attempt to free up file + -- descriptors when they have run out, it is your responsibility to + -- ensure that this doesn't happen. + -- ** Standard handles -- | Three handles are allocated during program initialisation, @@ -151,6 +161,7 @@ module System.IO ( hPutBuf, -- :: Handle -> Ptr a -> Int -> IO () hGetBuf, -- :: Handle -> Ptr a -> Int -> IO Int #if !defined(__NHC__) && !defined(__HUGS__) + hGetBufSome, -- :: Handle -> Ptr a -> Int -> IO Int hPutBufNonBlocking, -- :: Handle -> Ptr a -> Int -> IO Int hGetBufNonBlocking, -- :: Handle -> Ptr a -> Int -> IO Int #endif @@ -171,9 +182,9 @@ module System.IO ( -- -- The default 'TextEncoding' is the same as the default encoding -- on your system, which is also available as 'localeEncoding'. - -- (GHC note: on Windows, currently 'localeEncoding' is always - -- 'latin1'; there is no support for encoding and decoding using - -- the ANSI code page). + -- (GHC note: on Windows, we currently do not support double-byte + -- encodings; if the console\'s code page is unsupported, then + -- 'localeEncoding' will be 'latin1'.) -- -- Encoding and decoding errors are always detected and reported, -- except during lazy I/O ('hGetContents', 'getContents', and @@ -190,6 +201,7 @@ module System.IO ( utf16, utf16le, utf16be, utf32, utf32le, utf32be, localeEncoding, + char8, mkTextEncoding, #endif @@ -234,10 +246,12 @@ import System.Posix.Types #ifdef __GLASGOW_HASKELL__ import GHC.Base -import GHC.IO hiding ( onException ) +import GHC.IO hiding ( bracket, onException ) import GHC.IO.IOMode import GHC.IO.Handle.FD +import qualified GHC.IO.FD as FD import GHC.IO.Handle +import GHC.IO.Handle.Text ( hGetBufSome, hPutStrLn ) import GHC.IORef import GHC.IO.Exception ( userError ) import GHC.IO.Encoding @@ -313,8 +327,7 @@ putStr s = hPutStr stdout s -- | The same as 'putStr', but adds a newline character. putStrLn :: String -> IO () -putStrLn s = do putStr s - putChar '\n' +putStrLn s = hPutStrLn stdout s -- | The 'print' function outputs a value of any printable type to the -- standard output device. @@ -412,13 +425,6 @@ readIO s = case (do { (x,t) <- reads s ; hReady :: Handle -> IO Bool hReady h = hWaitForInput h 0 --- | The same as 'hPutStr', but adds a newline character. - -hPutStrLn :: Handle -> String -> IO () -hPutStrLn hndl str = do - hPutStr hndl str - hPutChar hndl '\n' - -- | Computation 'hPrint' @hdl t@ writes the string representation of @t@ -- given by the 'shows' function to the file or channel managed by @hdl@ -- and appends a newline. @@ -436,7 +442,9 @@ hPrint hdl = hPutStrLn hdl . show -- | @'withFile' name mode act@ opens a file using 'openFile' and passes -- the resulting handle to the computation @act@. The handle will be -- closed on exit from 'withFile', whether by normal termination or by --- raising an exception. +-- raising an exception. If closing the handle raises an exception, then +-- this exception will be raised by 'withFile' rather than any exception +-- raised by 'act'. withFile :: FilePath -> IOMode -> (Handle -> IO r) -> IO r withFile name mode = bracket (openFile name mode) hClose @@ -468,6 +476,8 @@ fixIO k = do -- Assume a unix platform, where text and binary I/O are identical. openBinaryFile = openFile hSetBinaryMode _ _ = return () + +type CMode = Int #endif -- | The function creates a temporary file in ReadWrite mode. @@ -543,10 +553,10 @@ openTempFile' loc tmp_dir template binary mode = do oflags = oflags1 .|. binary_flags #endif -#ifdef __NHC__ +#if defined(__NHC__) findTempName x = do h <- openFile filepath ReadWriteMode return (filepath, h) -#else +#elif defined(__GLASGOW_HASKELL__) findTempName x = do fd <- withFilePath filepath $ \ f -> c_open f oflags mode @@ -557,12 +567,20 @@ openTempFile' loc tmp_dir template binary mode = do then findTempName (x+1) else ioError (errnoToIOError loc errno Nothing (Just tmp_dir)) else do - -- XXX We want to tell fdToHandle what the filepath is, - -- as any exceptions etc will only be able to report the - -- fd currently + + (fD,fd_type) <- FD.mkFD fd ReadWriteMode Nothing{-no stat-} + False{-is_socket-} + True{-is_nonblock-} + + h <- mkHandleFromFD fD fd_type filepath ReadWriteMode False{-set non-block-} + (Just localeEncoding) + + return (filepath, h) +#else h <- fdToHandle fd `onException` c_close fd return (filepath, h) #endif + where filename = prefix ++ show x ++ suffix filepath = tmp_dir `combine` filename @@ -601,8 +619,7 @@ foreign import ccall "getpid" c_getpid :: IO Int -- $locking -- Implementations should enforce as far as possible, at least locally to the -- Haskell process, multiple-reader single-writer locking on files. --- That is, /there may either be many handles on the same file which manage --- input, or just one handle on the file which manages output/. If any +-- That is, /there may either be many handles on the same file which manage input, or just one handle on the file which manages output/. If any -- open or semi-closed handle is managing a file for output, no new -- handle can be allocated for that file. If any open or semi-closed -- handle is managing a file for input, new handles can only be allocated