title: Redirect users according to http_referrer
body: <p>I recently updated my website. My problem is that:</p>
  
  <p>There are few hyperlinks of my previous site in pdfs and word files  located in webpages.
  Moreover there are few hyperlinks of my previous site in few webpages.</p>
  
  <p>What I want, is to redirect the traffic coming from those files and urls to a new url.</p>
  
  <p>I tried modifying .htaccess as following:</p>
  
  <pre><code>&lt;IfModule mod_rewrite.c&gt;
  RewriteEngine On
  RewriteCond %{HTTP_REFERER} ^http://www.referrer-url.com/ [NC]
  RewriteRule \.pdf http://my-new-url.com/ [L,R]
  &lt;/IfModule&gt;
  </code></pre>
  
  <p>But nothing appears</p>