title: Replace string that contains CRLF?
body: <p>I'm reformatting a file, and I want to perform the following steps:</p>
  
  <ol>
  <li>Replace double CRLF's with a temporary character sequence (<code>$CRLF$</code> or something)</li>
  <li>Remove all CRLF's in the whole file</li>
  <li>Go back and replace the double CRLF's.</li>
  </ol>
  
  <p>So input like this:</p>
  
  <pre><code>This is a paragraph
  of text that has
  been manually fitted
  into a certain colum
  width.
  
  This is another
  paragraph of text
  that is the same.
  </code></pre>
  
  <p>Will become</p>
  
  <pre><code>This is a paragraph of text that has been manually fitted into a certain colum width.
  
  This is another paragraph of text that is the same.
  </code></pre>
  
  <p>It seems this should be possible by piping the input through a few simple <code>sed</code> programs, but I'm not sure how to refer to <code>CRLF</code> in <code>sed</code> (to use in <code>sed 's/&lt;CRLF&gt;&lt;CRLF&gt;/$CRLF$/'</code>). Or maybe there's a better way of doing this?</p>