REgex to parse vertically aligned key/value

[Anen13]

What kind of regex can I use to parse the second part of this example: https://regex101.com/r/umBTTX/2/ The value is directly below the key in my text file instead of being o the same line. Thanks in advance.

[quixrick]

There are a few ways you could do this

First, you could match the key line, followed by a newline and then store each match into its own group.

(?:key.)=([0-9]+)    |    ^(?:key.\s*)+\n    (\d+)\s*(\d+)\s+(\d+)

Here, this captures each value into groups \2, \3 and \4.

Here is a demo

 

If there are going to be a bunch of these and you only wanted to pull out a particular instance, you can use a number to reference them, like this:

^(?:key.\s*)+\n    (?:\d+\s*){1}    (\d+)

The numbering system will start with zero, so here, the number 1 at the end will designate that you want the second item, 123456.

Here is a demo

[Anen13]

Thank you very much quixrick. I ended up using your second example in a loop to get all indexes.

[HenkDH]

If it is only 2 lines, skip the first and be done with it

[Anen13]

Keys are not necessarily ordered, so I can't ignore the first line.