How to write a regular expression with negation?

Question

PHP

We need a regular expression that searches from links and selects those that lead not to pages, but to pictures, for example. Those. with extension. But with an extension other than html, php, etc. Please note that pages are without extension.
I made this one:

preg_match("#\.(?!htm|html|asp|aspx|php)$#Uum", $url)

I've tried many more but I can't get the desired result.

Answer 1

In general, I solved the problem with two if

if (preg_match("#/[^.]*\.[^.]*$#Uui", $url)) {
  if (preg_match("#(?<!htm|html|asp|aspx|php)$#Uui", $url)) {
    continue;
  }
}

Answer 2

So if you need pictures, then look for pictures

if(preg_match('/\.(jpg|png|jpeg|bmp|gif|svg)$/', $url)) {
  //картинка
} else {
  //не картинка
}