Best way to cache resized images using PHP and MySQL

Question

What would be the best practice way to handle the caching of images using PHP.

The filename is currently stored in a MySQL database which is renamed to a GUID on upl

Answer 1

One note worth adding is to make sure you're code does not generate "unauthorized" sizes of these images.

So the following URL will create a 200x200 version of image 1234 if one doesn't already exist. I'd highly suggest you make sure that the requested URL contains image dimensions you support.

/images/get/200x200/1234.jpg

A malicious person could start requesting random URLs, always altering the height & width of the image. This would cause your server some serious issues b/c it will be sitting there, essentially under attack, generating images of sizes you do not support.

/images/get/0x1/1234.jpg
/images/get/0x2/1234.jpg
...
/images/get/0x9999999/1234.jpg
/images/get/1x1/1234.jpg
...
etc

Here's a random snip of code illustrating this: