title: bash autocompletion with file names
body: <p>I can't get a simple bash autocompletion function to work. I need to autocomplete file names from a predefined directory so it will look like this:</p>
  
  <pre><code>$ cmd log&lt;TAB&gt;&lt;TAB&gt;
  file1.log file2.log file3.log   
  </code></pre>
  
  <p>Where files are from <code>/var/log/app</code>.</p>