#include <stdio.h>

void testinstrlib(char *buf, int len) {
  if (len < 1) return;
  buf[len] = 0;

  // we support three input cases
  if (buf[0] == '0')
    printf("Looks like a zero to me!\n");
  else if (buf[0] == '1')
    printf("Pretty sure that is a one!\n");
  else
    printf("Neither one or zero? How quaint!\n");
}