+#include <locale.h>
+#include <string.h>
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+# define WIN32_LEAN_AND_MEAN /* avoid including junk */
+# include <windows.h>
+# include <stdio.h>
+#endif
+
+/* Return the codeset of the current locale, if this is easily deducible.
+ Otherwise, return "". */
+static char *
+ctype_codeset (void)
+{
+ static char buf[2 + 10 + 1];
+ size_t buflen = 0;
+ char const *locale = setlocale (LC_CTYPE, NULL);
+ char *codeset = buf;
+ size_t codesetlen;
+ codeset[0] = '\0';
+
+ if (locale && locale[0])
+ {
+ /* If the locale name contains an encoding after the dot, return it. */
+ char *dot = strchr (locale, '.');
+
+ if (dot)
+ {
+ /* Look for the possible @... trailer and remove it, if any. */
+ char *codeset_start = dot + 1;
+ char const *modifier = strchr (codeset_start, '@');
+
+ if (! modifier)
+ codeset = codeset_start;
+ else
+ {
+ codesetlen = modifier - codeset_start;
+ if (codesetlen < sizeof buf)
+ {
+ codeset = memcpy (buf, codeset_start, codesetlen);
+ codeset[codesetlen] = '\0';
+ }
+ }
+ }
+ }
+
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+ /* If setlocale is successful, it returns the number of the
+ codepage, as a string. Otherwise, fall back on Windows API
+ GetACP, which returns the locale's codepage as a number (although
+ this doesn't change according to what the 'setlocale' call specified).
+ Either way, prepend "CP" to make it a valid codeset name. */
+ codesetlen = strlen (codeset);
+ if (0 < codesetlen && codesetlen < sizeof buf - 2)
+ memmove (buf + 2, codeset, codesetlen + 1);
+ else
+ sprintf (buf + 2, "%u", GetACP ());
+ codeset = memcpy (buf, "CP", 2);
+#endif
+ return codeset;
+}
+
+