X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=System%2FIO.hs;h=dfa589dc2a2db84ca644c21748b87e05b0f9066b;hb=8afc9fecd586d3c4f7ef9c69fb1686a79e5f441d;hp=6f0b01736615fd88202aa98e70e37dcb1791d527;hpb=d3e67963a7ab917876e3ec6fa95b791e74bada8d;p=ghc-base.git diff --git a/System/IO.hs b/System/IO.hs index 6f0b017..dfa589d 100644 --- a/System/IO.hs +++ b/System/IO.hs @@ -1,4 +1,4 @@ -{-# OPTIONS_GHC -fno-implicit-prelude #-} +{-# OPTIONS_GHC -XNoImplicitPrelude #-} ----------------------------------------------------------------------------- -- | -- Module : System.IO @@ -16,14 +16,14 @@ module System.IO ( -- * The IO monad - IO, -- instance MonadFix - fixIO, -- :: (a -> IO a) -> IO a + IO, -- instance MonadFix + fixIO, -- :: (a -> IO a) -> IO a -- * Files and handles - FilePath, -- :: String + FilePath, -- :: String - Handle, -- abstract, instance of: Eq, Show. + Handle, -- abstract, instance of: Eq, Show. -- ** Standard handles @@ -36,20 +36,21 @@ module System.IO ( -- ** Opening files - openFile, -- :: FilePath -> IOMode -> IO Handle + withFile, + openFile, -- :: FilePath -> IOMode -> IO Handle IOMode(ReadMode,WriteMode,AppendMode,ReadWriteMode), -- ** Closing files - hClose, -- :: Handle -> IO () + hClose, -- :: Handle -> IO () -- ** Special cases -- | These functions are also exported by the "Prelude". - readFile, -- :: FilePath -> IO String - writeFile, -- :: FilePath -> String -> IO () - appendFile, -- :: FilePath -> String -> IO () + readFile, -- :: FilePath -> IO String + writeFile, -- :: FilePath -> String -> IO () + appendFile, -- :: FilePath -> String -> IO () -- ** File locking @@ -59,33 +60,33 @@ module System.IO ( -- ** Determining and changing the size of a file - hFileSize, -- :: Handle -> IO Integer + hFileSize, -- :: Handle -> IO Integer #ifdef __GLASGOW_HASKELL__ hSetFileSize, -- :: Handle -> Integer -> IO () #endif -- ** Detecting the end of input - hIsEOF, -- :: Handle -> IO Bool - isEOF, -- :: IO Bool + hIsEOF, -- :: Handle -> IO Bool + isEOF, -- :: IO Bool -- ** Buffering operations BufferMode(NoBuffering,LineBuffering,BlockBuffering), - hSetBuffering, -- :: Handle -> BufferMode -> IO () - hGetBuffering, -- :: Handle -> IO BufferMode - hFlush, -- :: Handle -> IO () + hSetBuffering, -- :: Handle -> BufferMode -> IO () + hGetBuffering, -- :: Handle -> IO BufferMode + hFlush, -- :: Handle -> IO () -- ** Repositioning handles - hGetPosn, -- :: Handle -> IO HandlePosn - hSetPosn, -- :: HandlePosn -> IO () + hGetPosn, -- :: Handle -> IO HandlePosn + hSetPosn, -- :: HandlePosn -> IO () HandlePosn, -- abstract, instance of: Eq, Show. - hSeek, -- :: Handle -> SeekMode -> Integer -> IO () + hSeek, -- :: Handle -> SeekMode -> Integer -> IO () SeekMode(AbsoluteSeek,RelativeSeek,SeekFromEnd), #if !defined(__NHC__) - hTell, -- :: Handle -> IO Integer + hTell, -- :: Handle -> IO Integer #endif -- ** Handle properties @@ -94,83 +95,94 @@ module System.IO ( hIsReadable, hIsWritable, -- :: Handle -> IO Bool hIsSeekable, -- :: Handle -> IO Bool - -- ** Terminal operations + -- ** Terminal operations (not portable: GHC\/Hugs only) #if !defined(__NHC__) - hIsTerminalDevice, -- :: Handle -> IO Bool + hIsTerminalDevice, -- :: Handle -> IO Bool - hSetEcho, -- :: Handle -> Bool -> IO () - hGetEcho, -- :: Handle -> IO Bool + hSetEcho, -- :: Handle -> Bool -> IO () + hGetEcho, -- :: Handle -> IO Bool #endif - -- ** Showing handle state + -- ** Showing handle state (not portable: GHC only) #ifdef __GLASGOW_HASKELL__ - hShow, -- :: Handle -> IO String + hShow, -- :: Handle -> IO String #endif -- * Text input and output -- ** Text input - hWaitForInput, -- :: Handle -> Int -> IO Bool - hReady, -- :: Handle -> IO Bool - hGetChar, -- :: Handle -> IO Char - hGetLine, -- :: Handle -> IO [Char] - hLookAhead, -- :: Handle -> IO Char - hGetContents, -- :: Handle -> IO [Char] + hWaitForInput, -- :: Handle -> Int -> IO Bool + hReady, -- :: Handle -> IO Bool + hGetChar, -- :: Handle -> IO Char + hGetLine, -- :: Handle -> IO [Char] + hLookAhead, -- :: Handle -> IO Char + hGetContents, -- :: Handle -> IO [Char] -- ** Text output - hPutChar, -- :: Handle -> Char -> IO () - hPutStr, -- :: Handle -> [Char] -> IO () - hPutStrLn, -- :: Handle -> [Char] -> IO () - hPrint, -- :: Show a => Handle -> a -> IO () + hPutChar, -- :: Handle -> Char -> IO () + hPutStr, -- :: Handle -> [Char] -> IO () + hPutStrLn, -- :: Handle -> [Char] -> IO () + hPrint, -- :: Show a => Handle -> a -> IO () -- ** Special cases for standard input and output -- | These functions are also exported by the "Prelude". - interact, -- :: (String -> String) -> IO () - putChar, -- :: Char -> IO () - putStr, -- :: String -> IO () - putStrLn, -- :: String -> IO () - print, -- :: Show a => a -> IO () - getChar, -- :: IO Char - getLine, -- :: IO String - getContents, -- :: IO String - readIO, -- :: Read a => String -> IO a - readLn, -- :: Read a => IO a + interact, -- :: (String -> String) -> IO () + putChar, -- :: Char -> IO () + putStr, -- :: String -> IO () + putStrLn, -- :: String -> IO () + print, -- :: Show a => a -> IO () + getChar, -- :: IO Char + getLine, -- :: IO String + getContents, -- :: IO String + readIO, -- :: Read a => String -> IO a + readLn, -- :: Read a => IO a -- * Binary input and output - openBinaryFile, -- :: FilePath -> IOMode -> IO Handle - hSetBinaryMode, -- :: Handle -> Bool -> IO () -#if !defined(__NHC__) - hPutBuf, -- :: Handle -> Ptr a -> Int -> IO () - hGetBuf, -- :: Handle -> Ptr a -> Int -> IO Int -#endif + withBinaryFile, + openBinaryFile, -- :: FilePath -> IOMode -> IO Handle + 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 + hPutBufNonBlocking, -- :: Handle -> Ptr a -> Int -> IO Int + hGetBufNonBlocking, -- :: Handle -> Ptr a -> Int -> IO Int #endif -- * Temporary files -#ifdef __GLASGOW_HASKELL__ openTempFile, openBinaryTempFile, -#endif ) where +import Control.Exception.Base + +#ifndef __NHC__ +import Data.Bits +import Data.List +import Data.Maybe +import Foreign.C.Error +import Foreign.C.Types +import System.Posix.Internals +#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.Exception +import GHC.IO hiding ( onException ) +import GHC.IO.IOMode +import GHC.IO.Handle.FD +import GHC.IO.Handle +import GHC.IORef +import GHC.IO.Exception ( userError ) +-- import GHC.Exception import GHC.Num -import GHC.Read +import Text.Read import GHC.Show #endif @@ -178,8 +190,7 @@ import GHC.Show import Hugs.IO import Hugs.IOExts import Hugs.IORef -import Hugs.Prelude ( throw, Exception(NonTermination) ) -import System.IO.Unsafe ( unsafeInterleaveIO ) +import System.IO.Unsafe ( unsafeInterleaveIO ) #endif #ifdef __NHC__ @@ -214,11 +225,13 @@ import IO , hIsOpen, hIsClosed -- :: Handle -> IO Bool , hIsReadable, hIsWritable -- :: Handle -> IO Bool , hIsSeekable -- :: Handle -> IO Bool + , bracket , IO () , FilePath -- :: String ) -import NHC.IOExtras (fixIO) +import NHC.IOExtras (fixIO, hPutBuf, hGetBuf) +import NHC.FFI (Ptr) #endif -- ----------------------------------------------------------------------------- @@ -290,13 +303,12 @@ interact f = do s <- getContents -- The file is read lazily, on demand, as with 'getContents'. readFile :: FilePath -> IO String -readFile name = openFile name ReadMode >>= hGetContents +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 f txt = bracket (openFile f WriteMode) hClose - (\hdl -> hPutStr hdl txt) +writeFile f txt = withFile f WriteMode (\ hdl -> hPutStr hdl txt) -- | The computation 'appendFile' @file str@ function appends the string @str@, -- to the file @file@. @@ -308,8 +320,7 @@ writeFile f txt = bracket (openFile f WriteMode) hClose -- > main = appendFile "squares" (show [(x,x*x) | x <- [0,0.1..2]]) appendFile :: FilePath -> String -> IO () -appendFile f txt = bracket (openFile f AppendMode) hClose - (\hdl -> hPutStr hdl txt) +appendFile f txt = withFile f AppendMode (\ hdl -> hPutStr hdl txt) -- | The 'readLn' function combines 'getLine' and 'readIO'. @@ -323,11 +334,11 @@ readLn = do l <- getLine readIO :: Read a => String -> IO a readIO s = case (do { (x,t) <- reads s ; - ("","") <- lex t ; + ("","") <- lex t ; return x }) of - [x] -> return x - [] -> ioError (userError "Prelude.readIO: no parse") - _ -> ioError (userError "Prelude.readIO: ambiguous parse") + [x] -> return x + [] -> ioError (userError "Prelude.readIO: no parse") + _ -> ioError (userError "Prelude.readIO: ambiguous parse") #endif /* __GLASGOW_HASKELL__ */ #ifndef __NHC__ @@ -338,12 +349,12 @@ readIO s = case (do { (x,t) <- reads s ; -- -- * 'System.IO.Error.isEOFError' if the end of file has been reached. -hReady :: Handle -> IO Bool -hReady h = hWaitForInput h 0 +hReady :: Handle -> IO Bool +hReady h = hWaitForInput h 0 -- | The same as 'hPutStr', but adds a newline character. -hPutStrLn :: Handle -> String -> IO () +hPutStrLn :: Handle -> String -> IO () hPutStrLn hndl str = do hPutStr hndl str hPutChar hndl '\n' @@ -358,10 +369,24 @@ hPutStrLn hndl str = do -- -- * 'System.IO.Error.isPermissionError' if another system resource limit would be exceeded. -hPrint :: Show a => Handle -> a -> IO () -hPrint hdl = hPutStrLn hdl . show +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 @@ -385,6 +410,119 @@ 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. +-- +-- The file is creates with permissions such that only the current +-- user can read\/write it. +-- +-- With some exceptions (see below), the file will be created securely +-- in the sense that an attacker should not be able to cause +-- openTempFile to overwrite another file on the filesystem using your +-- credentials, by putting symbolic links (on Unix) in the place where +-- the temporary file is to be created. On Unix the @O_CREAT@ and +-- @O_EXCL@ flags are used to prevent this attack, but note that +-- @O_EXCL@ is sometimes not supported on NFS filesystems, so if you +-- rely on this behaviour it is best to use local filesystems only. +-- +openTempFile :: FilePath -- ^ Directory in which to create the file + -> String -- ^ File name template. If the template is \"foo.ext\" then + -- the created 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 + -- First case: template contains no '.'s. Just re-reverse it. + (rev_suffix, "") -> (reverse rev_suffix, "") + -- Second case: template contains at least one '.'. Strip the + -- dot from the prefix and prepend it to the suffix (if we don't + -- do this, the unique number will get added after the '.' and + -- thus be part of the extension, which is wrong.) + (rev_suffix, '.':rest) -> (reverse rest, '.':reverse rev_suffix) + -- Otherwise, something is wrong, because (break (== '.')) should + -- always return a pair with either the empty string or a string + -- beginning with '.' as the second component. + _ -> error "bug in System.IO.openTempFile" + +#ifndef __NHC__ + oflags1 = rw_flags .|. o_EXCL + + binary_flags + | binary = o_BINARY + | otherwise = 0 + + oflags = oflags1 .|. binary_flags +#endif + +#ifdef __NHC__ + findTempName x = do h <- openFile filepath ReadWriteMode + return (filepath, h) +#else + findTempName x = do + fd <- withFilePath filepath $ \ f -> + c_open f oflags 0o600 + 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 `onException` c_close fd + return (filepath, h) +#endif + where + filename = prefix ++ show x ++ suffix + filepath = tmp_dir `combine` filename + + -- XXX bits copied from System.FilePath, since that's not available here + combine a b + | null b = a + | null a = b + | last a == pathSeparator = a ++ b + | otherwise = a ++ [pathSeparator] ++ b + +#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 + +#ifndef __NHC__ +-- XXX Copied from GHC.Handle +std_flags, output_flags, rw_flags :: CInt +std_flags = o_NONBLOCK .|. o_NOCTTY +output_flags = std_flags .|. o_CREAT +rw_flags = output_flags .|. o_RDWR +#endif + +#ifdef __NHC__ +foreign import ccall "getpid" c_getpid :: IO Int +#endif + -- $locking -- Implementations should enforce as far as possible, at least locally to the -- Haskell process, multiple-reader single-writer locking on files. @@ -403,24 +541,3 @@ hSetBinaryMode _ _ = return () -- 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 '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