Question

For example, for a string:

http://www/host/a/b/c/topic/d/e/f/topic/last.html

I want to get value of “b” and “c”, which are value of string before FIRST “topic”.

If I use: .+/(.+)/(.+)/topic/(.+), I will get “e” and “f”. I know it is greedy mode, so it matched second “topic”. But if I changed to lazy mode, like .+?/(.+?)/(.+?)/topic/(.+), it was still not working.

Answer 1

I tend to use something more like:

[^/]+/([^/]+)/([^/]+)/topic/(.+)

The idea is instead of matching any character, you match up to the next slash. The brackets, [], define a character class, the tilde, ~, means ‘not’, so [^/] matches everything except a slash.