how to use regular expression to match strings followed by some keyword and multiple lines

I have a string like this:

...
xxxx
xxx

keyword1 xxxxx
xxxx
xxxx
xxxxx keyword2 yyyy
xxx
xxxx

xxx
...

where the x and y's are just random chars. I need to match the first "keyword2 yyyy" that appears after keyword1, and there may be multiple lines after keyword1. How do I write the regular expression? Thanks!

You can use this regex,

^(?s).*keyword1.*?(keyword2 yyyy).*$

Explanation:

• ^ --> start of string
• (?s) --> Enables dot to match new lines
• .* keyword1.*? --> Matches a string that contains keyword1 preceded and succeeded by any characters doing non-greedy match
• (keyword2 yyyy) --> matches the string of your interest
• .*$ --> followed by any characters and finally end of input

Demo