find group of machting characters

[bowoo king]

Hello,

I would like to use a RegEx to find a group of machting characters

string example:
2020-04-30T14:17:41.581Z <PLC0040:[STX/2]4110168 200001742340020110400201914002019101

this string contains twice : 40020191

but the value of the characters may vary, so instead of the example the following is also possible 12345678.

When the group of characters is known i use:

(?-s)(?i)40020191.*40020191

But now it needs to be more generic. So only looking for a duplication of a group of 8 characters in a string.

How can i do this?

Thanks in advance!
Boris

[Alan Kilborn]

@bowoo-king

I certainly might be inclined to try (?-s)(\d{8}).*?\1

[Alan Kilborn]

@bowoo-king said in find group of machting characters:

duplication of a group of 8 characters in a string

The example showed digits so that’s what my solution was tailored to.
But…
If it is truly “characters” then this might be more appropriate:
(?-s)(.{8}).*?\1