Mine

char* strndup(const char *s, int n)
{
    int i;
    char *r;
    for(i=0; i<n && s[i] != 0 ; i++);
    r = calloc(i+1, sizeof(char));
    strncpy(r, s, n);
    r[i] = 0;
    printf("i:%i, s:%s, r:%s;\n", i, s, r);
    return r;
}