#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <limits.h>

size_t confstr(int name, char *buf, size_t len);
char string[512];

int main()
{
        int i;
        size_t size;
        for (i=0; i<INT_MAX; i++) {
                size = confstr(i, NULL, (size_t) 0);
                if (errno != B_BAD_VALUE)
                        printf("%ld confstr %ld %s\n", i, size, strerror(errno));
                if (size != 0) {
                        size = confstr(i, string, sizeof(string));
                        printf("%ld value %s\n", i, string);
                }
        }
}