Call nl_langinfo(CODESET) to get the name of the locale encoding on Unix

[ghc-base.git] / GHC / IO / Encoding / Iconv.hs

diff --git a/GHC/IO/Encoding/Iconv.hs b/GHC/IO/Encoding/Iconv.hs
index 237468a..25e22ab 100644 (file)
--- a/GHC/IO/Encoding/Iconv.hs
+++ b/GHC/IO/Encoding/Iconv.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS_GHC -fno-implicit-prelude -#include "HsBase.h" #-}
+{-# OPTIONS_GHC -fno-implicit-prelude #-}
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  GHC.IO.Encoding.Iconv
@@ -25,6 +25,8 @@ module GHC.IO.Encoding.Iconv (
 #endif
  ) where
 
+#include "HsBaseConfig.h"
+
 #if !defined(mingw32_HOST_OS)
 
 #undef DEBUG_DUMP
@@ -98,7 +100,15 @@ utf32be = unsafePerformIO (mkTextEncoding "UTF32BE")
 
 {-# NOINLINE localeEncoding #-}
 localeEncoding :: TextEncoding
-localeEncoding = unsafePerformIO (mkTextEncoding "")
+localeEncoding = unsafePerformIO $ do
+#if HAVE_LANGINFO_H
+   cstr <- c_localeEncoding -- use nl_langinfo(CODESET) to get the encoding
+                               -- if we have it
+   r <- peekCString cstr
+   mkTextEncoding r
+#else
+   mkTextEncoding "" -- GNU iconv accepts "" to mean the -- locale encoding.
+#endif
 
 -- We hope iconv_t is a storable type.  It should be, since it has at least the
 -- value -1, which is a possible return value from iconv_open.
@@ -114,6 +124,9 @@ foreign import ccall unsafe "iconv"
     iconv :: IConv -> Ptr CString -> Ptr CSize -> Ptr CString -> Ptr CSize
          -> IO CSize
 
+foreign import ccall unsafe "localeEncoding"
+    c_localeEncoding :: IO CString
+
 haskellChar :: String
 #ifdef WORDS_BIGENDIAN
 haskellChar | charSize == 2 = "UTF16BE"