title: Why must I use \x1b not \ to represent an escape character
body: <p>I've read that <code>\x1b</code> represents the escape character, but isn't <code>'\'</code> by itself the escape character? A tutorial wants me to write</p>
  
  <pre><code>write(STDOUT_FILENO, "\x1b[2J", 4);
  </code></pre>
  
  <p>to clear the screen. Why won't <code>'\[2J'</code> do the job?</p>