#include <stdio.h>
#include <wchar.h>
#include <locale.h>
#include <errno.h>

int main()
{
	setlocale(LC_CTYPE, "de_DE.UTF-8");
	errno = EINVAL;
	printf("%d\n", fwide(stderr, 0));
	perror("äöü");
	printf("%d\n", fwide(stderr, 0));
	fwprintf(stderr, L"äöü\n");
	printf("%d\n", fwide(stderr, 0));
	perror("äöü");
	return 0;
}