convert utf8 to localcharset

iconv_utf8_to_localcharset.c

#include <iconv.h>
#include <localcharset.h>

static iconv_t g_utf8_to_localcharset;

static int init_iconv ()
{
  g_utf8_to_localcharset = NULL;
#if _WIN32
  const char* charset = locale_charset ();
  if (strcmp (charset, "UTF-8") != 0)
  {
    g_utf8_to_localcharset = iconv_open (charset, "UTF-8");
    if (g_utf8_to_localcharset == (void*)-1)
    {
      g_utf8_to_localcharset = NULL;
      return -1;
    }
  }
#endif

  return 0;
}

static char* to_utf8 (const char* str)
{
  char* p_str = NULL;
  if (g_utf8_to_localcharset)
  {
    size_t src_len = strlen (str);
    size_t dst_len = src_len * 4;
    char*  src_str = str;
    char*  dst_str = (char*)calloc (1, dst_len);
    p_str          = dst_str;

    iconv (g_utf8_to_localcharset, &src_str, &src_len, &dst_str, &dst_len);
  }
  else
  {
    p_str = strdup (str);
  }
  return p_str;
}