+#ifdef mingw32_HOST_OS
+ System.Win32.moveFileEx opath npath System.Win32.mOVEFILE_REPLACE_EXISTING
+#else
+ System.Posix.rename opath npath
+#endif
+
+#endif /* __GLASGOW_HASKELL__ */
+
+{- |@'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. The permissions of /old/ are
+copied to /new/, if possible.
+-}
+
+copyFile :: FilePath -> FilePath -> IO ()
+#ifdef __NHC__
+copyFile fromFPath toFPath =
+ do readFile fromFPath >>= writeFile toFPath
+ Prelude.catch (copyPermissions fromFPath toFPath)
+ (\_ -> return ())
+#else
+copyFile fromFPath toFPath =
+ copy `Prelude.catch` (\exc -> throw $ ioeSetLocation exc "copyFile")
+ where copy = bracket (openBinaryFile fromFPath ReadMode) hClose $ \hFrom ->
+ bracketOnError openTmp cleanTmp $ \(tmpFPath, hTmp) ->
+ do allocaBytes bufferSize $ copyContents hFrom hTmp
+ hClose hTmp
+ ignoreIOExceptions $ copyPermissions fromFPath tmpFPath
+ renameFile tmpFPath toFPath
+ openTmp = openBinaryTempFile (takeDirectory toFPath) ".copyFile.tmp"
+ cleanTmp (tmpFPath, hTmp)
+ = do ignoreIOExceptions $ hClose hTmp
+ ignoreIOExceptions $ removeFile tmpFPath
+ bufferSize = 1024
+
+ copyContents hFrom hTo buffer = do
+ count <- hGetBuf hFrom buffer bufferSize
+ when (count > 0) $ do
+ hPutBuf hTo buffer count
+ copyContents hFrom hTo buffer
+
+ ignoreIOExceptions io = io `catch` ioExceptionIgnorer
+ ioExceptionIgnorer :: IOException -> IO ()
+ ioExceptionIgnorer _ = return ()
+#endif
+
+-- | 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
+-- path. Note that it is impossible to guarantee that the
+-- implication (same file\/dir \<=\> same canonicalizedPath) holds
+-- in either direction: this function can make only a best-effort
+-- attempt.
+canonicalizePath :: FilePath -> IO FilePath
+canonicalizePath fpath =
+ withCString fpath $ \pInPath ->
+ allocaBytes long_path_size $ \pOutPath ->
+#if defined(mingw32_HOST_OS)
+ alloca $ \ppFilePart ->
+ do c_GetFullPathName pInPath (fromIntegral long_path_size) pOutPath ppFilePart
+#else
+ do c_realpath pInPath pOutPath
+#endif
+ path <- peekCString pOutPath
+ return (normalise path)
+ -- normalise does more stuff, like upper-casing the drive letter
+
+#if defined(mingw32_HOST_OS)
+foreign import stdcall unsafe "GetFullPathNameA"
+ c_GetFullPathName :: CString
+ -> CInt
+ -> CString
+ -> Ptr CString
+ -> IO CInt
+#else
+foreign import ccall unsafe "realpath"
+ c_realpath :: CString
+ -> CString
+ -> IO CString
+#endif
+
+-- | '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
+-- is the path to the found executable or Nothing if there isn't
+-- such executable. For example (findExecutable \"ghc\")
+-- gives you the path to GHC.
+findExecutable :: String -> IO (Maybe FilePath)
+findExecutable binary =
+#if defined(mingw32_HOST_OS)
+ withCString binary $ \c_binary ->
+ withCString ('.':exeExtension) $ \c_ext ->
+ allocaBytes long_path_size $ \pOutPath ->
+ alloca $ \ppFilePart -> do
+ res <- c_SearchPath nullPtr c_binary c_ext (fromIntegral long_path_size) pOutPath ppFilePart
+ if res > 0 && res < fromIntegral long_path_size
+ then do fpath <- peekCString pOutPath
+ return (Just fpath)
+ else return Nothing
+
+foreign import stdcall unsafe "SearchPathA"
+ c_SearchPath :: CString
+ -> CString
+ -> CString
+ -> CInt
+ -> CString
+ -> Ptr CString
+ -> IO CInt
+#else
+ do
+ path <- getEnv "PATH"
+ search (splitSearchPath path)
+ where
+ fileName = binary <.> exeExtension
+
+ search :: [FilePath] -> IO (Maybe FilePath)
+ search [] = return Nothing
+ search (d:ds) = do
+ let path = d </> fileName
+ b <- doesFileExist path
+ if b then return (Just path)
+ else search ds
+#endif