Provide a raw ByteString version of FilePath and environment APIs

The new module System.Posix.ByteString provides exactly the same API
as System.Posix, except that:

  - There is a new type: RawFilePath = ByteString

  - All functions mentioning FilePath in the System.Posix API
    use RawFilePath in the System.Posix.ByteString API

  - RawFilePaths are not subject to Unicode locale encoding and
    decoding, unlike FilePaths.  They are the exact bytes passed to and
    returned from the underlying POSIX API.

  - Similarly for functions that deal in environment
    strings (System.Posix.Env): these use untranslated ByteStrings
    in System.Posix.Environment

  - There is a new function

     System.Posix.ByteString.getArgs :: [ByteString]

    returning the raw untranslated arguments as passed to exec() when
    the program was started.

1 files changed, 155 insertions, 0 deletions

diff --git a/System/Posix/Directory/ByteString.hsc b/System/Posix/Directory/ByteString.hsc
new file mode 100644
index 0000000..9159d05
--- /dev/null
+++ b/System/Posix/Directory/ByteString.hsc
@@ -0,0 +1,155 @@
+{-# LANGUAGE ForeignFunctionInterface #-}
+{-# OPTIONS_GHC -fno-warn-unused-imports #-}
+#if __GLASGOW_HASKELL__ >= 701
+{-# LANGUAGE Trustworthy #-}
+#endif
+
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  System.Posix.Directory.ByteString
+-- Copyright   :  (c) The University of Glasgow 2002
+-- License     :  BSD-style (see the file libraries/base/LICENSE)
+-- 
+-- Maintainer  :  libraries@haskell.org
+-- Stability   :  provisional
+-- Portability :  non-portable (requires POSIX)
+--
+-- String-based POSIX directory support
+--
+-----------------------------------------------------------------------------
+
+module System.Posix.Directory.ByteString (
+   -- * Creating and removing directories
+   createDirectory, removeDirectory,
+
+   -- * Reading directories
+   DirStream,
+   openDirStream,
+   readDirStream,
+   rewindDirStream,   
+   closeDirStream,
+   DirStreamOffset,
+   tellDirStream,
+   seekDirStream,
+
+   -- * The working dirctory
+   getWorkingDirectory,
+   changeWorkingDirectory,
+   changeWorkingDirectoryFd,
+  ) where
+
+import System.IO.Error
+import System.Posix.Types
+import Foreign
+import Foreign.C
+
+import Data.ByteString.Char8 as BC
+
+import System.Posix.Directory.Common
+import System.Posix.ByteString.FilePath
+
+-- | @createDirectory dir mode@ calls @mkdir@ to
+--   create a new directory, @dir@, with permissions based on
+--  @mode@.
+createDirectory :: RawFilePath -> FileMode -> IO ()
+createDirectory name mode =
+  withFilePath name $ \s -> 
+    throwErrnoPathIfMinus1Retry_ "createDirectory" name (c_mkdir s mode)  
+    -- POSIX doesn't allow mkdir() to return EINTR, but it does on
+    -- OS X (#5184), so we need the Retry variant here.
+
+foreign import ccall unsafe "mkdir"
+  c_mkdir :: CString -> CMode -> IO CInt
+
+-- | @openDirStream dir@ calls @opendir@ to obtain a
+--   directory stream for @dir@.
+openDirStream :: RawFilePath -> IO DirStream
+openDirStream name =
+  withFilePath name $ \s -> do
+    dirp <- throwErrnoPathIfNullRetry "openDirStream" name $ c_opendir s
+    return (DirStream dirp)
+
+foreign import ccall unsafe "__hsunix_opendir"
+   c_opendir :: CString  -> IO (Ptr CDir)
+
+-- | @readDirStream dp@ calls @readdir@ to obtain the
+--   next directory entry (@struct dirent@) for the open directory
+--   stream @dp@, and returns the @d_name@ member of that
+--  structure.
+readDirStream :: DirStream -> IO RawFilePath
+readDirStream (DirStream dirp) =
+  alloca $ \ptr_dEnt  -> loop ptr_dEnt
+ where
+  loop ptr_dEnt = do
+    resetErrno
+    r <- c_readdir dirp ptr_dEnt
+    if (r == 0)
+	 then do dEnt <- peek ptr_dEnt
+		 if (dEnt == nullPtr)
+                    then return BC.empty
+		    else do
+	 	     entry <- (d_name dEnt >>= peekFilePath)
+		     c_freeDirEnt dEnt
+		     return entry
+	 else do errno <- getErrno
+		 if (errno == eINTR) then loop ptr_dEnt else do
+		 let (Errno eo) = errno
+		 if (eo == 0)
+                    then return BC.empty
+		    else throwErrno "readDirStream"
+
+-- traversing directories
+foreign import ccall unsafe "__hscore_readdir"
+  c_readdir  :: Ptr CDir -> Ptr (Ptr CDirent) -> IO CInt
+
+foreign import ccall unsafe "__hscore_free_dirent"
+  c_freeDirEnt  :: Ptr CDirent -> IO ()
+
+foreign import ccall unsafe "__hscore_d_name"
+  d_name :: Ptr CDirent -> IO CString
+
+
+-- | @getWorkingDirectory@ calls @getcwd@ to obtain the name
+--   of the current working directory.
+getWorkingDirectory :: IO RawFilePath
+getWorkingDirectory = do
+  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 <- peekFilePath 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"
+
+foreign import ccall unsafe "getcwd"
+   c_getcwd   :: Ptr CChar -> CSize -> IO (Ptr CChar)
+
+foreign import ccall unsafe "__hsunix_long_path_size"
+  long_path_size :: Int
+
+-- | @changeWorkingDirectory dir@ calls @chdir@ to change
+--   the current working directory to @dir@.
+changeWorkingDirectory :: RawFilePath -> IO ()
+changeWorkingDirectory path =
+  modifyIOError (`ioeSetFileName` (BC.unpack path)) $
+    withFilePath path $ \s -> 
+       throwErrnoIfMinus1Retry_ "changeWorkingDirectory" (c_chdir s)
+
+foreign import ccall unsafe "chdir"
+   c_chdir :: CString -> IO CInt
+
+removeDirectory :: RawFilePath -> IO ()
+removeDirectory path =
+  modifyIOError (`ioeSetFileName` BC.unpack path) $
+    withFilePath path $ \s ->
+       throwErrnoIfMinus1Retry_ "removeDirectory" (c_rmdir s)
+
+foreign import ccall unsafe "rmdir"
+   c_rmdir :: CString -> IO CInt