y, we can use <code>ls</code> to verify
          that there is a copy of <code>unix_commands.txt</code>:</p>

        <pre><code>user@computer:~$ ls
Desktop/ ... unix_commands.txt ...</code></pre>

        <p>Using <code>cat unix_commands.txt</code> will show the same output of UNIX
          commands.</p>

        <blockquote>
          <p><strong>Recap</strong>: we've seen two special directories: two dots <code>..</code>
            represents the parent directory (one directory up), while a single
    