Splunk Search

Key-Value extraction using rex function

josknigh
Engager

Is it possible to use the rex command to do a dynamic key=value extraction where they key is a also a regular expression?

I know this can be done with a transform using:

REGEX = (,*?)=(.*?)

FORMAT = $1::$2

Can I do the same thing using rex instead? Maybe something like:

rex field=_raw "(?P<\\FIELDNAME>.*?)=(?<\\VALUE>.*?)"

Is their something I'm missing in the group naming syntax?

I'm looking for a way to do this at search-time rather than index-time without writing a transform.

lguinn2
Legend

I don't know how to do this with rex, but have you looked at using the DELIMS key word in transforms.conf? If there is a regular pattern in your data that defines fields

name:value name2:value2

then you can specify that with

DELIMS = " ", ":"

More details re: transforms.conf are here Take a look at the examples at the very end of the page.

Got questions? Get answers!

Join the Splunk Community Slack to learn, troubleshoot, and make connections with fellow Splunk practitioners in real time!

Meet up IRL or virtually!

Join Splunk User Groups to connect and learn in-person by region or remotely by topic or industry.

Get Updates on the Splunk Community!

Modernize your Splunk Apps – Introducing Python 3.13 in Splunk

We are excited to announce that the upcoming releases of Splunk Enterprise 10.2.x and Splunk Cloud Platform ...

Step into “Hunt the Insider: An Splunk ES Premier Mystery” to catch a cybercriminal ...

After a whole week of being on call, you fell asleep on your keyboard, and you hit a sequence of buttons that ...

SplunkTrust Application Period is Officially OPEN!

It's that time, folks! The application/nomination period for the 2026-2027 SplunkTrust is officially open. If ...