Regex - Optional Positive Lookbehind

Question

I'm trying to match such that all the characters after the last / and before . gets matched. My current challenge is that . is only sometimes present.

I have an example here: https://regex101.com/r/ThWZwX/3

Where I'm hoping to match the 'match' text in both scenarios.

Thanks,

Answer 1

You can use negated character class in a capture group without any need of a lookahead:

.*\/([^.]*)

RegEx Demo

We use .*\\/ to match last / by using a greedy match of .* and then we use negated character class [^.]* to match until we get a dot or everything if dot is not found.

Also note that we use ([^.]*) to capture this match.

Answer 2

No need for anything complex

/([^/.]*)(?!.*/)

https://regex101.com/r/KHyXcJ/1