X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=System%2FIO.hs;h=3d3893d58581ea5aefb849415027bc11b6ce193e;hb=1a2c75698b74fe40e3cd91854c3f6a64e1dac348;hp=0d9d0298736c25a7ec44da8f2432eed67ca79a64;hpb=0720957fe6b813845dc6e0239ab0ecdb2eb193cc;p=ghc-base.git diff --git a/System/IO.hs b/System/IO.hs index 0d9d029..3d3893d 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 @@ -37,20 +37,20 @@ module System.IO ( -- ** Opening files withFile, - openFile, -- :: FilePath -> IOMode -> IO Handle + 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 @@ -60,33 +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 @@ -95,89 +95,91 @@ 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 withBinaryFile, - openBinaryFile, -- :: FilePath -> IOMode -> IO Handle - hSetBinaryMode, -- :: Handle -> Bool -> IO () - hPutBuf, -- :: Handle -> Ptr a -> Int -> IO () - hGetBuf, -- :: Handle -> Ptr a -> Int -> IO Int + 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 (not portable: GHC only) + -- * 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.String 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.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.Num -import GHC.Read +import Text.Read import GHC.Show #endif @@ -185,9 +187,7 @@ import GHC.Show import Hugs.IO import Hugs.IOExts import Hugs.IORef -import Hugs.Prelude ( throw, Exception(NonTermination) ) -import Control.Exception ( bracket ) -import System.IO.Unsafe ( unsafeInterleaveIO ) +import System.IO.Unsafe ( unsafeInterleaveIO ) #endif #ifdef __NHC__ @@ -300,7 +300,7 @@ 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@. @@ -331,11 +331,11 @@ 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__ @@ -346,12 +346,12 @@ 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' @@ -366,8 +366,8 @@ 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 @@ -409,9 +409,22 @@ hSetBinaryMode _ _ = return () -- | 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 create file will be \"fooXXX.ext\" where XXX is some + -- 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 @@ -425,8 +438,24 @@ openTempFile' loc tmp_dir template binary = do pid <- c_getpid findTempName pid where - (prefix,suffix) = break (=='.') template + -- 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 @@ -434,23 +463,42 @@ openTempFile' loc tmp_dir template binary = do | otherwise = 0 oflags = oflags1 .|. binary_flags +#endif +#ifdef __NHC__ + findTempName x = do h <- openFile filepath ReadWriteMode + return (filepath, h) +#else findTempName x = do fd <- withCString filepath $ \ f -> - c_open f oflags 0o666 - if fd < 0 + 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 - h <- fdToHandle' fd Nothing False filepath ReadWriteMode True - `catchException` \e -> do c_close fd; throw e - return (filepath, h) + -- 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 ++ [pathSeparator] ++ filename + 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 @@ -460,6 +508,7 @@ pathSeparator = '\\' pathSeparator = '/' #endif +#ifndef __NHC__ -- XXX Copied from GHC.Handle std_flags = o_NONBLOCK .|. o_NOCTTY output_flags = std_flags .|. o_CREAT @@ -467,6 +516,11 @@ read_flags = std_flags .|. o_RDONLY write_flags = output_flags .|. o_WRONLY rw_flags = output_flags .|. o_RDWR append_flags = write_flags .|. o_APPEND +#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 @@ -486,24 +540,3 @@ append_flags = write_flags .|. o_APPEND -- 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