Splunk Search

How to extract a string that starts with certain words or letters?

harry521
New Member

I'd like to use rex to extract the event string that starts with certain words or letters, possibly ends with certain words or letters. For example I have a event string like "blah blah blah Start blah blah blah End".

I can do something like:

mySearch|rex field=_raw "Start(?<"myField">.*)End"

I want my result not only "myField" but also including "Start" and "End". How can I do it?

0 Karma

woodcock
Esteemed Legend

Is this a trick question?

 mySearch | rex field=_raw "(?<myField>Start.*End)"
0 Karma

DalJeanis
Legend

you just move the parenthesis to be around whatever you want to capture.

Then you can go over to regex101.com and test to make sure you got it right. (Over there, you leave off the quotes and occasionally some character-escaping you had to do in splunk.)

0 Karma

harry521
New Member

I guess I didn't make myself clear. The end result I'd like to show is "Start <"myField"> End" from the original one. I end up with a "dirty" way to implement it as using "eval result=Start.<"myField">.End" to concatenate the strings after extracting myField.

Another way to explain what I want to achieve is to get rid of anything before "Start", and after "End".

0 Karma

ddrillic
Ultra Champion

Something in the spirit of -

| eval _raw="Start 999 End"
| rex field=_raw "(?<aaa>Start \d* End)"
0 Karma

richgalloway
SplunkTrust
SplunkTrust
mySearch|rex field=_raw "(?<"myField">Start.*End)"
---
If this reply helps you, Karma would be appreciated.
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