Fix #3189: add docs to findExecutable

[haskell-directory.git] / System / Directory.hs

diff --git a/System/Directory.hs b/System/Directory.hs
index 2579c02..48bb364 100644 (file)
--- a/System/Directory.hs
+++ b/System/Directory.hs
@@ -629,15 +629,14 @@ copyFile fromFPath toFPath =
 -- 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
+    do path <- System.Win32.getFullPathName fpath
 #else
+  withCString fpath $ \pInPath ->
+  allocaBytes long_path_size $ \pOutPath ->
     do c_realpath pInPath pOutPath
-#endif
        path <- peekCString pOutPath
+#endif
        return (normalise path)
         -- normalise does more stuff, like upper-casing the drive letter
 
@@ -661,11 +660,24 @@ 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.
+-- | 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 an executable with the given
+-- name was not found. For example (findExecutable \"ghc\") gives you
+-- the path to GHC.
+--
+-- The path returned by 'findExecutable' corresponds to the
+-- program that would be executed by 'System.Process.createProcess'
+-- when passed the same string (as a RawCommand, not a ShellCommand).
+--
+-- On Windows, 'findExecutable' calls the Win32 function 'SearchPath',
+-- which may search other places before checking the directories in
+-- @PATH@.  Where it actually searches depends on registry settings,
+-- but notably includes the directory containing the current
+-- executable. See
+-- <http://msdn.microsoft.com/en-us/library/aa365527.aspx> for more
+-- details.  
+--
 findExecutable :: String -> IO (Maybe FilePath)
 findExecutable binary =
 #if defined(mingw32_HOST_OS)
@@ -800,30 +812,11 @@ The operating system has no notion of current directory.
 getCurrentDirectory :: IO FilePath
 getCurrentDirectory = do
 #ifdef mingw32_HOST_OS
-  -- XXX: should use something from Win32
-  p <- mallocBytes long_path_size
-  go p long_path_size
-  where go p bytes = do
-         p' <- c_getcwd p (fromIntegral bytes)
-         if p' /= nullPtr 
-            then do s <- peekCString p'
-                    free p'
-                    return s
-            else do errno <- getErrno
-                    if errno == eRANGE
-                       then do let bytes' = bytes * 2
-                               p'' <- reallocBytes p bytes'
-                               go p'' bytes'
-                       else throwErrno "getCurrentDirectory"
+  System.Win32.getCurrentDirectory
 #else
   System.Posix.getWorkingDirectory
 #endif
 
-#ifdef mingw32_HOST_OS
-foreign import ccall unsafe "getcwd"
-   c_getcwd   :: Ptr CChar -> CSize -> IO (Ptr CChar)
-#endif
-
 {- |If the operating system has a notion of current directories,
 @'setCurrentDirectory' dir@ changes the current
 directory of the calling process to /dir/.
@@ -902,6 +895,8 @@ getModificationTime name =
  withFileStatus "getModificationTime" name $ \ st ->
  modificationTime st
 
+#endif /* !__HUGS__ */
+
 withFileStatus :: String -> FilePath -> (Ptr CStat -> IO a) -> IO a
 withFileStatus loc name f = do
   modifyIOError (`ioeSetFileName` name) $
@@ -933,18 +928,17 @@ fileNameEndClean :: String -> String
 fileNameEndClean name = if isDrive name then addTrailingPathSeparator name
                                         else dropTrailingPathSeparator name
 
-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 "HsDirectory.h __hscore_R_OK" r_OK :: CInt
+foreign import ccall unsafe "HsDirectory.h __hscore_W_OK" w_OK :: CInt
+foreign import ccall unsafe "HsDirectory.h __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 "HsDirectory.h __hscore_S_IRUSR" s_IRUSR :: CMode
+foreign import ccall unsafe "HsDirectory.h __hscore_S_IWUSR" s_IWUSR :: CMode
+foreign import ccall unsafe "HsDirectory.h __hscore_S_IXUSR" s_IXUSR :: CMode
 #ifdef mingw32_HOST_OS
 foreign import ccall unsafe "__hscore_S_IFDIR" s_IFDIR :: CMode
 #endif
 
-#endif /* !__HUGS__ */
 
 #ifdef __GLASGOW_HASKELL__
 foreign import ccall unsafe "__hscore_long_path_size"
@@ -1091,9 +1085,7 @@ The function doesn\'t verify whether the path exists.
 getTemporaryDirectory :: IO FilePath
 getTemporaryDirectory = do
 #if defined(mingw32_HOST_OS)
-  allocaBytes long_path_size $ \pPath -> do
-     _r <- c_GetTempPath (fromIntegral long_path_size) pPath
-     peekCString pPath
+  System.Win32.getTemporaryDirectory
 #else
   getEnv "TMPDIR"
 #if !__NHC__
@@ -1117,8 +1109,6 @@ foreign import ccall unsafe "__hscore_CSIDL_APPDATA"  csidl_APPDATA  :: CInt
 foreign import ccall unsafe "__hscore_CSIDL_WINDOWS"  csidl_WINDOWS  :: CInt
 foreign import ccall unsafe "__hscore_CSIDL_PERSONAL" csidl_PERSONAL :: CInt
 
-foreign import stdcall unsafe "GetTempPathA" c_GetTempPath :: CInt -> CString -> IO CInt
-
 raiseUnsupported :: String -> IO ()
 raiseUnsupported loc = 
    ioException (ioeSetErrorString (mkIOError UnsupportedOperation loc Nothing Nothing) "unsupported operation")