title: how to return to original binary file after converting with xxd
body: <p>When editing the file in vim  ,i  input <code>:%!xxd</code> to check  the ascii. </p>
  
  <pre><code>:%!xxd
  </code></pre>
  
  <p>Vim  quit if i input <code>:q</code>.</p>
  
  <pre><code>:q
  </code></pre>
  
  <p>I  want to return to the previous file to continue my work.<br>
  How can i do?</p>