Math operations in regex

Question

I need to add a number to a backreference while doing a replace operation.

e.g. I am rewriting a URL

www.site.com/doc.asp?doc=321&language=1
         


        

Answer 1

If you only have a few articles you could just brute force it

...doc=322 -> www.site.com/headline/100322.article
...doc=323 -> www.site.com/headline/100323.article
...doc=324 -> www.site.com/headline/100324.article
...etc

Math in regex, you see it here first.