title: How to compute path to file in public folder?
body: <p>I created a folder called <code>Uploads</code> in my <code>public</code> folder.</p>
  
  <p>I'd like to have people be able to click a link and download a file in that <code>Uploads</code> folder.</p>
  
  <p>Here's my code:</p>
  
  <pre><code>&lt;p&gt;
    &lt;b&gt;Certifications&lt;/b&gt;
  
    &lt;%= link_to @tutor.tutor_degrees.first.name, # =&gt; "AS Level English"
        root_path + @tutor.tutor_degrees.first.certification_scan %&gt;
  &lt;/p&gt;
  
  http://localhost:3000/Screen%20shot%202013-02-04%20at%206.01.11%20PM.png
  </code></pre>
  
  <p>It's missing the <code>/uploads/</code> bit in the URL path. </p>
  
  <p>If I add that string manually, I get a borked URL:</p>
  
  <pre><code>&lt;p&gt;
    &lt;b&gt;Certifications&lt;/b&gt;
    &lt;%= link_to @tutor.tutor_degrees.first.name,
        root_path + '/uploads/' + @tutor.tutor_degrees.first.certification_scan %&gt;
  &lt;/p&gt;
  
  http://uploads/Screen%20shot%202013-02-04%20at%206.01.11%20PM.png
  </code></pre>