Regex to include certain words but exclude another

Question

I am trying to write a regular expression which will check a URL contains certain words and excludes another.

The reason for this is I am trying to track traffic moving through my website and I don't want to count anyone who hits the Thank You page.

So for example:

• http://www.mywebsite.com/register-now/ - MATCH
• http://www.mywebsite.com/contact-us/ - MATCH
• http://www.mywebsite.com/register-now/thank-you - NO MATCH
• http://www.mywebsite.com/contact-us/thank-you - NO MATCH
• http://www.mywebsite.com/thank-you - NO MATCH

I have 2 words (register-now and contact-us) these must be in the URL. However I must ensure that 1 word (thank-you) is also not in the URL.

I have tried to use a negative lookahead to check that the URL does NOT contain thank-you but It is not working:

"^(?!.*\/thank\-you+)\/(contact\-us|register\-now)\/.*"

Answer 1

In a single regex you can use negative lookahead:

^(?!.*\/thank-you(?:\/|$))(?:.*\/)?(?:contact-us|register-now)\/

RegEx Demo

• (?!.*\/thank-you(?:\/|$)) is negative lookahead that will fail the match if URL has /thanks-you or /thank-you/.
• Use MULTILINE mode if your text contains multiple URLs in each line.