Splunk Search

REX and Lookups

HealyManTech
Explorer

I am trying to use a lookup table after I rex out some logs.

Here is an example:
index=* source=messages
| rex field=_raw "ACTION:[\w]\s(?.*) CODE"
| outputlookup actions.csv action OUTPUT desc AS desc
| table _time action desc

Can anyone help? Am I doing it wrong?

0 Karma
1 Solution

elliotproebstel
Champion

I think the display is eating some of your rex, so I'm not sure I can troubleshoot that part directly. If it's working at creating a field called action, then you should only need to revise your lookup line:

| lookup actions.csv action OUTPUT desc AS desc

That will work if the events contain a field called action. If they don't, (say, maybe they contain a field called ACTION), then you'd do this:

| lookup actions.csv action AS ACTION OUTPUT desc AS desc

The way you have it now, you are using the command outputlookup, which is used to literally "output a lookup file" (i.e. create a lookup file) rather than to use a lookup file to perform a lookup.

View solution in original post

0 Karma

elliotproebstel
Champion

I think the display is eating some of your rex, so I'm not sure I can troubleshoot that part directly. If it's working at creating a field called action, then you should only need to revise your lookup line:

| lookup actions.csv action OUTPUT desc AS desc

That will work if the events contain a field called action. If they don't, (say, maybe they contain a field called ACTION), then you'd do this:

| lookup actions.csv action AS ACTION OUTPUT desc AS desc

The way you have it now, you are using the command outputlookup, which is used to literally "output a lookup file" (i.e. create a lookup file) rather than to use a lookup file to perform a lookup.

0 Karma
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!

index This | What kind of room has no doors?

IndexEducation Cover Art Banner Cisco.png August 2026 Edition  Hayyy Splunk Education Enthusiasts and the ...

Optimize AI at Scale: Must-Attend Observability Sessions at .conf26

conf26   With nearly 70 breakout sessions on the docket, the .conf26 Observability track is designed to help ...

How much can you really learn in 3 minutes?

Observability can certainly be hard to understand – there's a lot of jargon and buzzwords and it seems to ...