title: what does strtok(NULL, "\n") do?
body: <blockquote>
    <p>The C library function char *strtok(char *str, const char *delim) breaks string str into a series of tokens using the delimiter delim.</p>
  </blockquote>
  
  <p>What happens when you put <code>s = strtok(NULL, "\n")</code>? what does it mean splitting null by <code>\n</code>?</p>