+{- |@'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.
+-}
+copyFile :: FilePath -> FilePath -> IO ()
+copyFile fromFPath toFPath =
+#if (!(defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ > 600))
+ do readFile fromFPath >>= writeFile toFPath
+ try (getPermissions fromFPath >>= setPermissions toFPath)
+ return ()
+#else
+ (bracket (openBinaryFile fromFPath ReadMode) hClose $ \hFrom ->
+ bracket (openBinaryFile toFPath WriteMode) hClose $ \hTo ->
+ allocaBytes bufferSize $ \buffer -> do
+ copyContents hFrom hTo buffer
+ try (getPermissions fromFPath >>= setPermissions toFPath)
+ return ()) `catch` (ioError . changeFunName)
+ where
+ bufferSize = 1024
+
+ changeFunName (IOError h iot fun str mb_fp) = IOError h iot "copyFile" str mb_fp
+
+ copyContents hFrom hTo buffer = do
+ count <- hGetBuf hFrom buffer bufferSize
+ when (count > 0) $ do
+ hPutBuf hTo buffer count
+ copyContents hFrom hTo buffer
+#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_TARGET_OS)
+ alloca $ \ppFilePart ->
+ do c_GetFullPathName pInPath (fromIntegral long_path_size) pOutPath ppFilePart
+#else
+ do c_realpath pInPath pOutPath
+#endif
+ peekCString pOutPath
+
+#if defined(mingw32_TARGET_OS)
+foreign import stdcall unsafe "GetFullPathName"
+ c_GetFullPathName :: CString
+ -> CInt
+ -> CString
+ -> Ptr CString
+ -> IO CInt
+#else
+foreign import ccall unsafe "realpath"
+ c_realpath :: CString
+ -> CString
+ -> IO CString
+#endif
+
+-- | 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 = do
+ path <- getEnv "PATH"
+ search (parseSearchPath path)
+ where
+#ifdef mingw32_TARGET_OS
+ fileName = binary `joinFileExt` "exe"
+#else
+ fileName = binary
+#endif
+
+ search :: [FilePath] -> IO (Maybe FilePath)
+ search [] = return Nothing
+ search (d:ds) = do
+ let path = d `joinFileName` fileName
+ b <- doesFileExist path
+ if b then return (Just path)
+ else search ds
+
+