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, 82 insertions, 0 deletions

diff --git a/System/Posix/Temp/ByteString.hsc b/System/Posix/Temp/ByteString.hsc
new file mode 100644
index 0000000..c5f8906
--- /dev/null
+++ b/System/Posix/Temp/ByteString.hsc
@@ -0,0 +1,82 @@
+{-# LANGUAGE ForeignFunctionInterface #-}
+#if __GLASGOW_HASKELL__ >= 701
+{-# LANGUAGE Trustworthy #-}
+#endif
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  System.Posix.Temp.ByteString
+-- Copyright   :  (c) Volker Stolz <vs@foldr.org>
+-- License     :  BSD-style (see the file libraries/base/LICENSE)
+--
+-- Maintainer  :  vs@foldr.org
+-- Stability   :  provisional
+-- Portability :  non-portable (requires POSIX)
+--
+-- POSIX environment support
+--
+-----------------------------------------------------------------------------
+
+module System.Posix.Temp.ByteString (
+
+    mkstemp
+
+{- Not ported (yet?):
+    tmpfile: can we handle FILE*?
+    tmpnam: ISO C, should go in base?
+    tempname: dito
+-}
+
+) where
+
+#include "HsUnix.h"
+
+import System.IO        (Handle)
+import System.Posix.IO
+import System.Posix.Types
+
+import Foreign.C hiding (
+     throwErrnoPath,
+     throwErrnoPathIf,
+     throwErrnoPathIf_,
+     throwErrnoPathIfNull,
+     throwErrnoPathIfMinus1,
+     throwErrnoPathIfMinus1_ )
+
+import System.Posix.ByteString.FilePath
+
+import Data.ByteString (ByteString)
+
+
+-- |'mkstemp' - make a unique filename and open it for
+-- reading\/writing (only safe on GHC & Hugs).
+-- The returned 'RawFilePath' is the (possibly relative) path of
+-- the created file, which is padded with 6 random characters.
+mkstemp :: ByteString -> IO (RawFilePath, Handle)
+mkstemp template = do
+#if defined(__GLASGOW_HASKELL__) || defined(__HUGS__)
+  withFilePath template $ \ ptr -> do
+    fd <- throwErrnoIfMinus1 "mkstemp" (c_mkstemp ptr)
+    name <- peekFilePath ptr
+    h <- fdToHandle (Fd fd)
+    return (name, h)
+#else
+  name <- mktemp (template ++ "XXXXXX")
+  h <- openFile name ReadWriteMode
+  return (name, h)
+
+-- |'mktemp' - make a unique file name
+-- This function should be considered deprecated
+
+mktemp :: ByteString -> IO RawFilePath
+mktemp template = do
+  withFilePath template $ \ ptr -> do
+    ptr <- throwErrnoIfNull "mktemp" (c_mktemp ptr)
+    peekFilePath ptr
+
+foreign import ccall unsafe "mktemp"
+  c_mktemp :: CString -> IO CString
+#endif
+
+foreign import ccall unsafe "HsUnix.h __hscore_mkstemp"
+  c_mkstemp :: CString -> IO CInt
+