Regular Expressions - Remove all lines after match

[#1]

I noticed that when I receive a Lazy Approval task response, the entire email thread is included in the Task Approver Comments.  I would like to Remove/Strip all lines of text in the Task Approver Comments that follow my matched <keyword>.

I'm using the Regular Expression action in Nintex and my pattern code is:

[\w\s,.:]\<keyword>:.* (In the image below, I used "Lazy" as my <keyword>)

This works great for the first line, but I have about 50 more lines below this that I'd like to remove in this action.

Is there a way to add to my formula to remove all characters after my keyword?

Thanks!

[#2]

Firstly, can I ask why you have a backslash escape "\" in front of the "L" in "Lazy"?  I don't think \L is a valid escape in .NET regular expressions.

I don't have a workflow readily to hand to experiment with at the moment. Unfortunately the Nintex implementation of Regex's is not well documented, but if it supports all the .NET options, then I think what you need is something like-

Pattern:     (?s)^([\w\s,.:]*Lazy:).*

Replace:    $1

It's incredibly dangerous to come up with Regex's on the fly like this (they never work first time!) but the basic idea is-

(?s)     Sets the "single line match" option, so "." matches newline as well as any character

^          Anchors the pattern to the start of the line

()          The first group collects up all the items you want to keep (everything up to and including "Lazy:")

.*          Everything else

Then replace with just the first match group.

I heartily recommend a google search for an online Regex tester. You can save hours of laboriously editing / publishing / testing workflows when you can see the Regex being executed live in your browser.

[#3]

Hi Colin,

I have been learning with Google as my mentor, so please forgive my lack of knowledge and ability to create proper syntax.  I decided that the EXTRACT function is more suited to what I'm trying to accomplish then the REPLACE function.  So, instead of trying to REPLACE/REMOVE all lines after my keyword, I decided to just EXTRACT the first 2 lines of the Approver Comments into a collection variable.  I used ^.*\n.*\n.* in my pattern to pickup the first 2 lines and it works great.

Thanks for your input!

[#4]

No problem. Regexs are something of a black art.