How to compare links?

Question

Yii

There is a need to compare 2 links.
But I ran into a problem that if you compare them as 2 lines, then, accordingly, any difference will consider them as different links.
How can I correctly compare addresses that essentially lead to the same page, but differ in appearance?
For example:

http://site.ru/index.html, 
http://site.ru/ 
http://site.ru/index
http://site.ru/index.htm 
site.ru/index

etc

Answer 1

I have come to a decision.)
Just a slash or extension is cut off at the end of compared links

Answer 2

Bring them to the same form, for example site.ru and compare

Answer 3

(ru\/?(index|\/))