X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=System%2FIO.hs;h=a5b9d7d2e3fae659e773eb9c8b0f41ea4b1c3669;hb=dd487472345cffd5b440f2e73f3244bf20a49eb7;hp=eee562cd8ed91287fa0110869849eed96cf894b9;hpb=b72dda8318394f238214364dc01b8963599f8cd6;p=ghc-base.git diff --git a/System/IO.hs b/System/IO.hs index eee562c..a5b9d7d 100644 --- a/System/IO.hs +++ b/System/IO.hs @@ -1,4 +1,4 @@ -{-# OPTIONS -fno-implicit-prelude #-} +{-# OPTIONS_GHC -fno-implicit-prelude #-} ----------------------------------------------------------------------------- -- | -- Module : System.IO @@ -6,7 +6,7 @@ -- License : BSD-style (see the file libraries/base/LICENSE) -- -- Maintainer : libraries@haskell.org --- Stability : provisional +-- Stability : stable -- Portability : portable -- -- The standard IO library. @@ -36,6 +36,7 @@ module System.IO ( -- ** Opening files + withFile, openFile, -- :: FilePath -> IOMode -> IO Handle IOMode(ReadMode,WriteMode,AppendMode,ReadWriteMode), @@ -57,9 +58,12 @@ module System.IO ( -- * Operations on handles - -- ** Determining the size of a file + -- ** Determining and changing the size of a file hFileSize, -- :: Handle -> IO Integer +#ifdef __GLASGOW_HASKELL__ + hSetFileSize, -- :: Handle -> Integer -> IO () +#endif -- ** Detecting the end of input @@ -93,7 +97,7 @@ module System.IO ( -- ** Terminal operations -#if !defined(__HUGS__) && !defined(__NHC__) +#if !defined(__NHC__) hIsTerminalDevice, -- :: Handle -> IO Bool hSetEcho, -- :: Handle -> Bool -> IO () @@ -141,25 +145,41 @@ module System.IO ( -- * Binary input and output -#if !defined(__NHC__) + withBinaryFile, openBinaryFile, -- :: FilePath -> IOMode -> IO Handle -#endif - -#if !defined(__HUGS__) && !defined(__NHC__) hSetBinaryMode, -- :: Handle -> Bool -> IO () hPutBuf, -- :: Handle -> Ptr a -> Int -> IO () hGetBuf, -- :: Handle -> Ptr a -> Int -> IO Int +#if !defined(__NHC__) && !defined(__HUGS__) + hPutBufNonBlocking, -- :: Handle -> Ptr a -> Int -> IO Int + hGetBufNonBlocking, -- :: Handle -> Ptr a -> Int -> IO Int #endif - module System.IO.Error, + -- * Temporary files + + openTempFile, + openBinaryTempFile, ) where +import Data.Bits +import Data.List +import Data.Maybe +import Foreign.C.Error +import Foreign.C.String +import System.Posix.Internals + +#ifdef __GLASGOW_HASKELL__ +import GHC.Exception as ExceptionBase hiding (catch) +#endif +#ifdef __HUGS__ +import Hugs.Exception as ExceptionBase +#endif + #ifdef __GLASGOW_HASKELL__ import GHC.Base import GHC.IOBase -- Together these four Prelude modules define import GHC.Handle -- all the stuff exported by IO for the GHC version import GHC.IO -import GHC.ST ( fixST ) import GHC.Exception import GHC.Num import GHC.Read @@ -169,6 +189,10 @@ import GHC.Show #ifdef __HUGS__ import Hugs.IO import Hugs.IOExts +import Hugs.IORef +import Hugs.Prelude ( throw, Exception(NonTermination) ) +import Control.Exception ( bracket ) +import System.IO.Unsafe ( unsafeInterleaveIO ) #endif #ifdef __NHC__ @@ -197,39 +221,25 @@ import IO , hGetContents -- :: Handle -> IO [Char] , hPutChar -- :: Handle -> Char -> IO () , hPutStr -- :: Handle -> [Char] -> IO () + , hPutStrLn -- :: Handle -> [Char] -> IO () + , hPrint -- :: Handle -> [Char] -> IO () + , hReady -- :: Handle -> [Char] -> IO () , hIsOpen, hIsClosed -- :: Handle -> IO Bool , hIsReadable, hIsWritable -- :: Handle -> IO Bool , hIsSeekable -- :: Handle -> IO Bool + , bracket , IO () , FilePath -- :: String ) -import NHC.Internal (unsafePerformIO) +import NHC.IOExtras (fixIO, hPutBuf, hGetBuf) +import NHC.FFI (Ptr) #endif -import System.IO.Error ( - isAlreadyExistsError, isDoesNotExistError, -- :: IOError -> Bool - isAlreadyInUseError, isFullError, - isEOFError, isIllegalOperation, - isPermissionError, isUserError, - - ioeGetErrorString, -- :: IOError -> String - ioeGetHandle, -- :: IOError -> Maybe Handle - ioeGetFileName, -- :: IOError -> Maybe FilePath - - try, -- :: IO a -> IO (Either IOError a) - - -- re-exports of Prelude names - IOError, - ioError, -- :: IOError -> IO a - userError, -- :: String -> IOError - catch -- :: IO a -> (IOError -> IO a) -> IO a - ) - -- ----------------------------------------------------------------------------- -- Standard IO -#ifndef __HUGS__ +#ifdef __GLASGOW_HASKELL__ -- | Write a character to the standard output device -- (same as 'hPutChar' 'stdout'). @@ -242,7 +252,7 @@ putChar c = hPutChar stdout c putStr :: String -> IO () putStr s = hPutStr stdout s --- | The same as 'putStrLn', but adds a newline character. +-- | The same as 'putStr', but adds a newline character. putStrLn :: String -> IO () putStrLn s = do putStr s @@ -299,12 +309,8 @@ readFile name = openFile name ReadMode >>= hGetContents -- | The computation 'writeFile' @file str@ function writes the string @str@, -- to the file @file@. - -writeFile :: FilePath -> String -> IO () -writeFile name str = do - hdl <- openFile name WriteMode - hPutStr hdl str - hClose hdl +writeFile :: FilePath -> String -> IO () +writeFile f txt = withFile f WriteMode (\ hdl -> hPutStr hdl txt) -- | The computation 'appendFile' @file str@ function appends the string @str@, -- to the file @file@. @@ -316,10 +322,7 @@ writeFile name str = do -- > main = appendFile "squares" (show [(x,x*x) | x <- [0,0.1..2]]) appendFile :: FilePath -> String -> IO () -appendFile name str = do - hdl <- openFile name AppendMode - hPutStr hdl str - hClose hdl +appendFile f txt = withFile f AppendMode (\ hdl -> hPutStr hdl txt) -- | The 'readLn' function combines 'getLine' and 'readIO'. @@ -338,14 +341,15 @@ readIO s = case (do { (x,t) <- reads s ; [x] -> return x [] -> ioError (userError "Prelude.readIO: no parse") _ -> ioError (userError "Prelude.readIO: ambiguous parse") -#endif /* __HUGS__ */ +#endif /* __GLASGOW_HASKELL__ */ +#ifndef __NHC__ -- | Computation 'hReady' @hdl@ indicates whether at least one item is --- available for input from handle "hdl". +-- available for input from handle @hdl@. -- -- This operation may fail with: -- --- * 'isEOFError' if the end of file has been reached. +-- * 'System.IO.Error.isEOFError' if the end of file has been reached. hReady :: Handle -> IO Bool hReady h = hWaitForInput h 0 @@ -363,25 +367,123 @@ hPutStrLn hndl str = do -- -- This operation may fail with: -- --- * 'isFullError' if the device is full; or +-- * 'System.IO.Error.isFullError' if the device is full; or -- --- * 'isPermissionError' if another system resource limit would be exceeded. +-- * 'System.IO.Error.isPermissionError' if another system resource limit would be exceeded. hPrint :: Show a => Handle -> a -> IO () hPrint hdl = hPutStrLn hdl . show +#endif /* !__NHC__ */ + +-- | @'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. +withFile :: FilePath -> IOMode -> (Handle -> IO r) -> IO r +withFile name mode = bracket (openFile name mode) hClose + +-- | @'withBinaryFile' name mode act@ opens a file using 'openBinaryFile' +-- and passes the resulting handle to the computation @act@. The handle +-- will be closed on exit from 'withBinaryFile', whether by normal +-- termination or by raising an exception. +withBinaryFile :: FilePath -> IOMode -> (Handle -> IO r) -> IO r +withBinaryFile name mode = bracket (openBinaryFile name mode) hClose -- --------------------------------------------------------------------------- -- fixIO -#ifdef __GLASGOW_HASKELL__ -fixIO :: (a -> IO a) -> IO a -fixIO m = stToIO (fixST (ioToST . m)) +#if defined(__GLASGOW_HASKELL__) || defined(__HUGS__) +fixIO :: (a -> IO a) -> IO a +fixIO k = do + ref <- newIORef (throw NonTermination) + ans <- unsafeInterleaveIO (readIORef ref) + result <- k ans + writeIORef ref result + return result + +-- NOTE: we do our own explicit black holing here, because GHC's lazy +-- blackholing isn't enough. In an infinite loop, GHC may run the IO +-- computation a few times before it notices the loop, which is wrong. #endif -#ifdef __NHC__ -fixIO :: (a -> IO a) -> IO a -fixIO f = let x = unsafePerformIO (f x) in return x + +#if defined(__NHC__) +-- Assume a unix platform, where text and binary I/O are identical. +openBinaryFile = openFile +hSetBinaryMode _ _ = return () +#endif + +-- | The function creates a temporary file in ReadWrite mode. +-- The created file isn\'t deleted automatically, so you need to delete it manually. +openTempFile :: FilePath -- ^ Directory in which to create the file + -> String -- ^ File name template. If the template is \"foo.ext\" then + -- the create file will be \"fooXXX.ext\" where XXX is some + -- random number. + -> IO (FilePath, Handle) +openTempFile tmp_dir template = openTempFile' "openTempFile" tmp_dir template False + +-- | Like 'openTempFile', but opens the file in binary mode. See 'openBinaryFile' for more comments. +openBinaryTempFile :: FilePath -> String -> IO (FilePath, Handle) +openBinaryTempFile tmp_dir template = openTempFile' "openBinaryTempFile" tmp_dir template True + +openTempFile' :: String -> FilePath -> String -> Bool -> IO (FilePath, Handle) +openTempFile' loc tmp_dir template binary = do + pid <- c_getpid + findTempName pid + where + -- We split off the last extension, so we can use .foo.ext files + -- for temporary files (hidden on Unix OSes). Unfortunately we're + -- below filepath in the hierarchy here. + (prefix,suffix) = case break (== '.') $ reverse template of + (rev_suffix, rev_prefix) -> + (reverse rev_prefix, reverse rev_suffix) + + oflags1 = rw_flags .|. o_EXCL + + binary_flags + | binary = o_BINARY + | otherwise = 0 + + oflags = oflags1 .|. binary_flags + + findTempName x = do + fd <- withCString filepath $ \ f -> + c_open f oflags 0o666 + if fd < 0 + then do + errno <- getErrno + if errno == eEXIST + 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 + h <- fdToHandle fd + `ExceptionBase.catchException` \e -> do c_close fd; throw e + return (filepath, h) + where + filename = prefix ++ show x ++ suffix + filepath = tmp_dir ++ [pathSeparator] ++ filename +#if __HUGS__ + fdToHandle fd = openFd (fromIntegral fd) False ReadWriteMode binary #endif +-- XXX Should use filepath library +pathSeparator :: Char +#ifdef mingw32_HOST_OS +pathSeparator = '\\' +#else +pathSeparator = '/' +#endif + +-- XXX Copied from GHC.Handle +std_flags = o_NONBLOCK .|. o_NOCTTY +output_flags = std_flags .|. o_CREAT +read_flags = std_flags .|. o_RDONLY +write_flags = output_flags .|. o_WRONLY +rw_flags = output_flags .|. o_RDWR +append_flags = write_flags .|. o_APPEND + -- $locking -- Implementations should enforce as far as possible, at least locally to the -- Haskell process, multiple-reader single-writer locking on files. @@ -399,4 +501,25 @@ fixIO f = let x = unsafePerformIO (f x) in return x -- the file until the entire contents of the file have been consumed. -- It follows that an attempt to write to a file (using 'writeFile', for -- example) that was earlier opened by 'readFile' will usually result in --- failure with 'isAlreadyInUseError'. +-- failure with 'System.IO.Error.isAlreadyInUseError'. + +-- ----------------------------------------------------------------------------- +-- Utils + +#ifdef __GLASGOW_HASKELL__ +-- Copied here to avoid recursive dependency with Control.Exception +bracket + :: IO a -- ^ computation to run first (\"acquire resource\") + -> (a -> IO b) -- ^ computation to run last (\"release resource\") + -> (a -> IO c) -- ^ computation to run in-between + -> IO c -- returns the value from the in-between computation +bracket before after thing = + block (do + a <- before + r <- catchException + (unblock (thing a)) + (\e -> do { after a; throw e }) + after a + return r + ) +#endif