Match only if word is contained within constraints, Regex - regex

Question

I am struggling with finding the regex to find a word that must be between two others.
in simple, my constraints are:
must begin with the word line con
must end with the next appearence of the word line
between these two must have the word session-timeout
may also contain other words between line con and line.
I wish to match on any block of text starting with line con and ending with the next instance of the word line, however I need them to only match if the word session-timeout is between them.
bonus points if you can tell me how to match for any number larger than 10 after session-timeout (eg. session-timeout 12 would match)
an example of where I would want it to match is:
line con 0
session-timeout 14
stopbits 1
line aux 0
stopbits 1
line vty 0 4
However, this should not match
line con 0
session-timeout 8
stopbits 1
line aux 0
stopbits 1
line vty 0 4
session-timeout 13
line vty 0 5
so far I have the regex expression (line con)(\s|\S)+?(session-timeout ){1}([0-9])(\s|\S)+?(line), however if it does not match a session-timeout within the terms, it simply ignores the first line, which is where I want it to stop looking.
Any help would be massivley appreciated!

Answer 1

You can use
(line con)(?:(?!line con)[\s\S])+?(session-timeout\s+)([1-9][0-9]+)[\s\S]+?(line)
See the regex demo. Details:
(line con) - Group 1: line con string
(?:(?!line con)[\s\S])+? - any char, one or more occurrences but as few as possible, that does not start line con char sequence
(session-timeout\s+) - Group 2: session-timeout string and one or more whitespaces
([1-9][0-9]+) - Group 3: a number from 10 and larger (if you want to allow any leading zeros, append 0* before [1-9])
[\s\S]+? - any one or more chars, as few as possible
(line) - Group 4: line.
Adjust the capturing groups as per your requirements.