title: Replace file in PHP
body: <p>I would like to replace one image file with another in PHP. Both have same name (123), but they are in different directory and should have different extension. I want to replace first image with second image.</p>
  
  <ol>
  <li>../images/123.gif</li>
  <li>../images/xxx/123.png</li>
  </ol>
  
  <p>Is it possible with any function? Thank you.</p>