regex - exclude substring contains more than 2 "/"

Question

I have a list of the following strings:

/fajwe/conv_1/routing/apwfe/afjwepfj
/fajwe/conv_2/routing/apwfe
/fajwe/conv_2/routing
/fajwe/conv_3/routing/apwfe/afjwepfj/awef
/fajwe/conv_4/routing/apwfe/afjwepfj/awef/0o09

I want a regex to only match string contains no more than 1 / after the word routing. Namely /fajwe/conv_2/routing/apwfe and /fajwe/conv_2/routing.

Currently I use the regex ^((?!rou\w+(\/\w+){2,}).)*$ but it matches nothing. How can I write a regex to exclude strings contains more than 2 / after the word routing?

I would love to learn how to achieve this using Negative Lookbehind. Many thanks!

Answer 1

Your regex matches what you are looking for with the multiline flag m as @revo pointed out.

^((?!rou\w+(\/\w+){2,}).)*$

You could also try it like this:

^\/fajwe\/conv_\d\/routing(?:\/[^\/]+)?$

Depending of your context of language you could \/ escape the forward slash