title: Add a plugin from Nagios Exchange to Nagios 3.x
body: <p>I just finished installing Nagios 3 in Ubuntu server and I'm not sure how I can add a third party plugin into it.</p>
  
  <p>The plugin is available : <a href="https://exchange.nagios.org/directory/Plugins/System-Metrics/File-System/check_file_ages_in_dirs/details" rel="nofollow">Here</a></p>
  
  <p>Thanks in advance for your help</p>