Splunk Search

Modify field to remove extra characters

terryjohn
Path Finder

I have a search that returns a user field i.e. user="username". This gets reported by one system as user="u'username'" this is generating false positives for unknown users.

I want to modify the user field, if necessary to remove the u' at the start and the ' at the end. I have a way but it seems cumbersome

| eval user=if(like(user,"u'%'"), mvindex(split(user,"'") ,1) ,user)

I'd be interested if there's a better way since I have another mis-report where the username has a : appended to it. using a similar eval but with an rtrim I could remove it but the search would be getting very heavy then.

| eval user=if(like(user,"u'%'"), mvindex(split(user,"'") ,1) ,user) | eval user=if(like(user,"%:"), rtrim(user,":") ,user)

I feel there ought to be a regular expression way of doing this but I can't work it out.

Thanks

Tags (4)
0 Karma
1 Solution

hrottenberg_spl
Splunk Employee
Splunk Employee

Here's a solution using the aforementioned replace command:

| makeresults | eval user="u'username" | replace u'* with *

(Everything prior to "| replace" is used to make a single sample event on which to test the replace. Omit it in your actual search.)

0 Karma

masonmorales
Influencer

Check out the replace command

woodcock
Esteemed Legend

terryjohn
Path Finder

Thanks both it took me a while to work it out that it was eval replace command not the other replace but with the right regex it seems to work

| eval user=replace(user,"(^u')?(.+)[':]$","\2")
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!

Automating Threat Operations and Threat Hunting with Recorded Future

    Automating Threat Operations and Threat Hunting with Recorded Future June 29, 2026 | Register   Is your ...

Keep the Learning Going with the New Best of .conf Hub

Hello Splunkers, With .conf26 getting closer, there’s already a lot of excitement building around this year’s ...

Splunk Community Badges!

  Hey everyone! Ready to earn some serious bragging rights in the community? Along with our existing badges ...