title: Can I use sed to manipulate a variable in bash?
body: <p>In my program, I would like to first get the user input, and insert a <code>\</code> before each <code>/</code>
  so I write this, but it doesn't work.</p>
  
  <pre><code>echo "input a website"
  read website
  
  sed '/\//i\/' $website
  </code></pre>