Insert string into string?
<p>I have a number of images being uploaded to a site with random file names e.g.</p>

<pre><code>http://www.mysite.com/uploads/images/apicture23.jpg
http://www.mysite.com/uploads/images/anotherpicture203.jpeg
http://www.mysite.com/uploads/images/another.picture203.png
http://www.mysite.com/uploads/images/athird-picture101.gif
</code></pre>

<p>Is it possible in PHP to somehow insert immediately before the file extension (<code>.jpg</code>, <code>.jpeg</code> <code>.png</code> or <code>.gif</code>) part of the url another string such as <code>-300x200</code> ?</p>
