-getExecDir cmd
- = allocaArray len $ \buf -> do
- ret <- getModuleFileName nullPtr buf len
- if ret == 0 then return Nothing
- else do s <- peekCString buf
- return (Just (reverse (drop (length cmd)
- (reverse (unDosifyPath s)))))
- where
- len = 2048::Int -- Plenty, PATH_MAX is 512 under Win32.
+getExecDir :: String -> IO (Maybe String)
+getExecDir cmd =
+ getExecPath >>= maybe (return Nothing) removeCmdSuffix
+ where unDosifyPath = subst '\\' '/'
+ initN n = reverse . drop n . reverse
+ removeCmdSuffix = return . Just . initN (length cmd) . unDosifyPath
+
+getExecPath :: IO (Maybe String)
+getExecPath =
+ allocaArray len $ \buf -> do
+ ret <- getModuleFileName nullPtr buf len
+ if ret == 0 then return Nothing
+ else liftM Just $ peekCString buf
+ where len = 2048 -- Plenty, PATH_MAX is 512 under Win32.
+
+foreign import stdcall unsafe "GetModuleFileNameA"
+ getModuleFileName :: Ptr () -> CString -> Int -> IO Int32