source: trunk/essentials/sys-apps/gawk/missing_d/memcmp.c

/*
 * memcmp --- compare strings.
 *
 * We use our own routine since it has to act like strcmp() for return
 * value, and the BSD manual says bcmp() only returns zero/non-zero.
 */

int
memcmp (s1, s2, l)
register char *s1, *s2;
register int l;
{
        for (; l-- > 0; s1++, s2++) {
                if (*s1 != *s2)
                        return (*s1 - *s2);
        }
        return (0);
}