title: Get the most recently updated file in PHP
body: <p>I need to get the latest updated file from number of files present under that directory starting with name file_(random number).css?
  there are number of file present like this:</p>
  <pre><code>file_12.css
  file_34.css
  file_14.css
  </code></pre>
  <p>I want to get the most recently updated file. is there any readymade function available to retrieve such file in PHP?</p>