Splunk Search

inputlookup and substring search

igorbukanov
Engager

We need to search if a part of URL in the log matches a string from an external file. As I can see, the method from http://splunk-base.splunk.com/answers/2457/inputlookup-against-a-list-of-bad-domains does not work as it matches against whole field values and we need to check for a substring match.

Currently as a workaround we use the command-line search and assemble the search in a shell script from the file so it looks like

search ... "*string1*" OR "*string2*" OR "*string3*" ...

But perhaps there is a better/faster way of doing the search especially given that our search list has been growing.

Tags (1)

ziegfried
Influencer

You can use a subsearch to create the wildcard-query from a lookup file (field1 is the csv column that contains the fragment to look for)

... [ | inputlookup mylookup | eval search="*"+field1+"*" | fields search ]

will expand to

... (( *value1* ) OR ( *value2*) ...

The values might need to be quoted:

... [ | inputlookup mylookup | eval search="\"*"+replace(field1,"\"","\\\"")+"*\"" | fields search ]

will expand to

... ( ( "*value1*" ) OR ( "*value2*" ) OR ( "*some value3*" ) OR ...

ziegfried
Influencer

If that solves your problem, please accept the answer by clicking on the checkmark on the left.

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!

Data Management Digest – September 2026

    Welcome to the September 2026 edition of Data Management Digest! September brought a fresh wave of ...

Federated Search for CloudWatch Unified Data Store Is Generally Available

As organizations modernize their cloud environments, AWS workloads generate more security, operational, and ...

Announcing Modern Navigation: A New Era of Splunk User Experience

We are excited to introduce the Modern Navigation feature in the Splunk Platform, available to both cloud and ...