title: Vim regex to substitute/escape pipe characters
body: <p>Let's suppose I have a line:</p>
  
  <pre><code>a|b|c
  </code></pre>
  
  <p>I'd like to run a regex to convert it to:</p>
  
  <pre><code>a\|b\|c
  </code></pre>
  
  <p>In most regex engines I'm familiar with, something like <code>s%\|%\\|%g</code> should work. If I try this in Vim, I get:</p>
  
  <pre><code>\|a\||\|b\||\|c
  </code></pre>
  
  <hr>
  
  <p>As it turns out, I discovered the answer while typing up this question. I'll submit it with my solution, anyway, as I was a bit surprised a search didn't turn up any duplicates.</p>