, copyFile -- :: FilePath -> FilePath -> IO ()
, canonicalizePath
+ , makeRelativeToCurrentDirectory
, findExecutable
-- * Existence tests
import System.Directory.Internals
import System.Environment ( getEnv )
+import System.FilePath
import System.IO.Error
import Control.Monad ( when, unless )
#ifdef __NHC__
import Directory
-import NHC.FFI
#endif /* __NHC__ */
#ifdef __HUGS__
import Hugs.Directory
#endif /* __HUGS__ */
-#if defined(__GLASGOW_HASKELL__) || defined(mingw32_HOST_OS)
import Foreign
import Foreign.C
-#endif
+
+{-# CFILES cbits/directory.c #-}
#ifdef __GLASGOW_HASKELL__
import Prelude
{- |@'copyFile' old new@ copies the existing file from /old/ to /new/.
If the /new/ file already exists, it is atomically replaced by the /old/ file.
-Neither path may refer to an existing directory.
+Neither path may refer to an existing directory. The permissions of /old/ are
+copied to /new/, if possible.
+-}
+
+{- NOTES:
+
+It's tempting to try to remove the target file before opening it for
+writing. This could be useful: for example if the target file is an
+executable that is in use, writing will fail, but unlinking first
+would succeed.
+
+However, it certainly isn't always what you want.
+
+ * if the target file is hardlinked, removing it would break
+ the hard link, but just opening would preserve it.
+
+ * opening and truncating will preserve permissions and
+ ACLs on the target.
+
+ * If the destination file is read-only in a writable directory,
+ we might want copyFile to fail. Removing the target first
+ would succeed, however.
+
+ * If the destination file is special (eg. /dev/null), removing
+ it is probably not the right thing. Copying to /dev/null
+ should leave /dev/null intact, not replace it with a plain
+ file.
+
+ * There's a small race condition between removing the target and
+ opening it for writing during which time someone might
+ create it again.
-}
copyFile :: FilePath -> FilePath -> IO ()
-copyFile fromFPath toFPath = do
- -- We try removing the target file before opening it for
- -- writing. In the event that the target file is locked or in
- -- use, this allows us to replace it safely. However, it
- -- leaves a race condition: someone else might create the file
- -- after we delete it, but there isn't much we can do about
- -- that.
+copyFile fromFPath toFPath =
#if (!(defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ > 600))
- contents <- readFile fromFPath
- try (removeFile toFPath)
- writeFile toFPath contents
- try (copyPermissions fromFPath toFPath)
- return ()
+ do readFile fromFPath >>= writeFile toFPath
+ try (copyPermissions fromFPath toFPath)
+ return ()
#else
- (bracket (openBinaryFile fromFPath ReadMode) hClose $ \hFrom -> do
- try (removeFile toFPath)
- bracket (openBinaryFile toFPath WriteMode) hClose $ \hTo -> do
+ (bracket (openBinaryFile fromFPath ReadMode) hClose $ \hFrom ->
+ bracket (openBinaryFile toFPath WriteMode) hClose $ \hTo ->
allocaBytes bufferSize $ \buffer -> do
copyContents hFrom hTo buffer
try (copyPermissions fromFPath toFPath)
copyContents hFrom hTo buffer
#endif
-#ifdef __GLASGOW_HASKELL__
-- | Given path referring to a file or directory, returns a
-- canonicalized path, with the intent that two paths referring
-- to the same file\/directory will map to the same canonicalized
-> CString
-> IO CString
#endif
-#else /* !__GLASGOW_HASKELL__ */
--- dummy implementation
-canonicalizePath :: FilePath -> IO FilePath
-canonicalizePath fpath = return fpath
-#endif /* !__GLASGOW_HASKELL__ */
+
+-- | 'makeRelative' the current directory.
+makeRelativeToCurrentDirectory :: FilePath -> IO FilePath
+makeRelativeToCurrentDirectory x = do
+ cur <- getCurrentDirectory
+ return $ makeRelative cur x
-- | Given an executable file name, searches for such file
-- in the directories listed in system PATH. The returned value
-> CString
-> Ptr CString
-> IO CInt
-# if !defined(__GLASGOW_HASKELL__)
-long_path_size :: Int
-long_path_size = 4096
-# endif
#else
do
path <- getEnv "PATH"
i = (length name) - 1
ec = name !! i
-foreign import ccall unsafe "__hscore_long_path_size"
- long_path_size :: Int
-
-foreign import ccall unsafe "__hscore_R_OK" r_OK :: CMode
-foreign import ccall unsafe "__hscore_W_OK" w_OK :: CMode
-foreign import ccall unsafe "__hscore_X_OK" x_OK :: CMode
+foreign import ccall unsafe "__hscore_R_OK" r_OK :: CInt
+foreign import ccall unsafe "__hscore_W_OK" w_OK :: CInt
+foreign import ccall unsafe "__hscore_X_OK" x_OK :: CInt
foreign import ccall unsafe "__hscore_S_IRUSR" s_IRUSR :: CMode
foreign import ccall unsafe "__hscore_S_IWUSR" s_IWUSR :: CMode
foreign import ccall unsafe "__hscore_S_IXUSR" s_IXUSR :: CMode
+foreign import ccall unsafe "__hscore_long_path_size"
+ long_path_size :: Int
+
+#else
+long_path_size :: Int
+long_path_size = 2048 -- // guess?
+
#endif /* __GLASGOW_HASKELL__ */
{- | Returns the current user's home directory.
-}
getHomeDirectory :: IO FilePath
getHomeDirectory =
-#if __GLASGOW_HASKELL__ && defined(mingw32_HOST_OS)
+#if defined(mingw32_HOST_OS)
allocaBytes long_path_size $ \pPath -> do
r <- c_SHGetFolderPath nullPtr csidl_PROFILE nullPtr 0 pPath
if (r < 0)
-}
getAppUserDataDirectory :: String -> IO FilePath
getAppUserDataDirectory appName = do
-#if __GLASGOW_HASKELL__ && defined(mingw32_HOST_OS)
+#if defined(mingw32_HOST_OS)
allocaBytes long_path_size $ \pPath -> do
r <- c_SHGetFolderPath nullPtr csidl_APPDATA nullPtr 0 pPath
when (r<0) (raiseUnsupported "System.Directory.getAppUserDataDirectory")
-}
getUserDocumentsDirectory :: IO FilePath
getUserDocumentsDirectory = do
-#if __GLASGOW_HASKELL__ && defined(mingw32_HOST_OS)
+#if defined(mingw32_HOST_OS)
allocaBytes long_path_size $ \pPath -> do
r <- c_SHGetFolderPath nullPtr csidl_PERSONAL nullPtr 0 pPath
when (r<0) (raiseUnsupported "System.Directory.getUserDocumentsDirectory")
-}
getTemporaryDirectory :: IO FilePath
getTemporaryDirectory = do
-#if __GLASGOW_HASKELL__ && defined(mingw32_HOST_OS)
+#if defined(mingw32_HOST_OS)
allocaBytes long_path_size $ \pPath -> do
r <- c_GetTempPath (fromIntegral long_path_size) pPath
peekCString pPath
catch (getEnv "TMPDIR") (\ex -> return "/tmp")
#endif
-#if __GLASGOW_HASKELL__ && defined(mingw32_HOST_OS)
+#if defined(mingw32_HOST_OS)
foreign import ccall unsafe "__hscore_getFolderPath"
c_SHGetFolderPath :: Ptr ()
-> CInt
projects / haskell-directory.git / blobdiff