Added wide character to utf8 and vice versa conversion functions.

Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

src/std/c_string.c

@@ -197,7 +197,7 @@ char *c_lowercase(const char* str) {
 }
 
 /* Convert a wide multibyte String to UTF8 */
-const char* c_utf8(const _TCHAR *wstr)
+const char* c_utf8(const mbchar_t *wstr)
 {
   const char *dst = NULL;
 
@@ -221,16 +221,16 @@ const char* c_utf8(const _TCHAR *wstr)
 }
 
 /* Convert a an UTF8 string to multibyte */
-const _TCHAR* c_multibyte(const char *str)
+const mbchar_t* c_multibyte(const char *str)
 {
 #ifdef _WIN32
-  _TCHAR *wstrTo = NULL;
+  mbchar_t *wstrTo = NULL;
   if(!str) return NULL;
 
   size_t len = strlen( str );
   int size_needed = MultiByteToWideChar(CP_UTF8, 0, str, len, NULL, 0);
   if(size_needed > 0) {
-    int size_char = (size_needed+1)*sizeof(_TCHAR);
+    int size_char = (size_needed+1)*sizeof(mbchar_t);
     wstrTo = c_malloc(size_char);
     memset( (void*)wstrTo, 0, size_char);
     MultiByteToWideChar(CP_UTF8, 0, str, -1, wstrTo, size_needed);
@@ -250,7 +250,7 @@ void c_free_utf8(char* buf)
 #endif
 }
 
-void c_free_multibyte(const _TCHAR* buf)
+void c_free_multibyte(const mbchar_t* buf)
 {
 #ifdef _WIN32
     SAFE_FREE(buf);

src/std/c_string.h

@@ -142,35 +142,90 @@ char *c_lowercase(const char* str);
 /**
  * @brief Convert a multibyte string to utf8 (Win32).
  *
+ * This function is part of the multi platform abstraction of basic file
+ * operations to handle various platform encoding correctly.
+ *
+ * Instead of using the standard file operations the multi platform aliases
+ * defined in c_private.h have to be used instead.
+ *
+ * To convert path names returned by these functions to the internally used
+ * utf8 format this function has to be used. The returned string has to
+ * be freed by c_free_utf(). On some platforms this method allocates memory
+ * and on others not but it has never to be cared about as long as
+ * c_free_utf8() is used.
+ *
  * @param  str     The multibyte encoded string to convert
  *
  * @return The malloced converted string or NULL on error.
+ *
+ * @see c_free_utf8()
+ * @see c_multibyte()
+ *
  */
-const char*   c_utf8(const _TCHAR *str);
+const char*   c_utf8(const mbchar_t *str);
 
 /**
  * @brief Convert a utf8 encoded string to multibyte (Win32).
  *
+ * This function is part of the multi platform abstraction of basic file
+ * operations to handle various platform encoding correctly.
+ *
+ * Instead of using the standard file operations the multi platform aliases
+ * defined in c_private.h have to be used instead.
+ *
+ * To convert path names as input for the cross platform functions from the
+ * internally used utf8 format, this function has to be used.
+ * The returned string has to be freed by c_free_multibyte(). On some
+ * platforms this method allocates memory and on others not but it has never
+ * sto be cared about as long as c_free_multibyte() is used.
+ *
  * @param  str     The utf8 string to convert.
  *
  * @return The malloced converted multibyte string or NULL on error.
+ *
+ * @see c_free_multibyte()
+ * @see c_utf8()
+ *
  */
-const _TCHAR* c_multibyte(const char *wstr);
+const mbchar_t* c_multibyte(const char *wstr);
 
 /**
- * @brief Free buffer malloced by c_utf8.
+ * @brief Free buffer malloced by c_utf8().
+ *
+ * This function is part of the multi platform abstraction of basic file
+ * operations to handle various platform encoding correctly.
+ *
+ * Instead of using the standard file operations the multi platform aliases
+ * defined in c_private.h have to be used instead.
+ *
+ * This function frees the memory that was allocated by a previous call to
+ * c_utf8().
  *
  * @param  buf     The buffer to free.
  *
+ * @see c_utf8()
+ *
  */
 void c_free_utf8(char* buf);
 
 /**
- * @brief Free buffer malloced by c_multibyte.
+ * @brief Free buffer malloced by c_multibyte().
+ *
+ * This function is part of the multi platform abstraction of basic file
+ * operations to handle various platform encoding correctly.
+ *
+ * Instead of using the standard file operations the multi platform aliases
+ * defined in c_private.h have to be used instead.
+ *
+ * This function frees the memory that was allocated by a previous call to
+ * c_multibyte().
  *
  * @param  buf     The buffer to free.
+ *
+ * @see c_multibyte()
+ *
  */
-void c_free_multibyte(const _TCHAR* buf);
+void c_free_multibyte(const mbchar_t* buf);
 
 /**
  * }@