Splunk Search

Regex issue

approachct
Path Finder

Having trouble with the below regex generated from the field extractor application
\w+:\\w+\\w+\(?P\w+\\w+)

When added to the search as below
index=utility sourcetype="componentcheck"|rex field=FILENAME \w+:\\w+\\w+\(?P\w+\\w+)

and example input of
d:\A\B\C\D\E\F.dll (there are back slashes between each letter)

I get an two of the same errors -
Error in 'rex' command: Encountered the following error while compiling the regex '\w+:\w+\w+(?P\w+\w+)': Regex: unmatched parentheses

What am I doing wrong?

Tags (1)

kushagra9120
Explorer

Try this:-

"[a-zA-Z]:(?:(?:\\[a-zA-Z]){5}\\)(?P[a-zA-Z].\w+)"

0 Karma

landen99
Motivator

Sample regex has many issues:

\w+:\\\w+\\\w+\(?P\w+\\\w+)

While the sample regex fails to escape the backslash correctly or name the capture group, here is what I think that you are trying to match:

| stats count | eval FILENAME="d:\\A\\B\\C\\D\\E\\F.dll"  | rex field=FILENAME "(\w+[\:\\\]+){3}(?<my_field>\w+\\\+\w+)" | table FILENAME, my_field
0 Karma

cstump_splunk
Splunk Employee
Splunk Employee

The first parenthesis is escaped: (
The regex engine thinks that there is an unmatched closing parenthesis at the end of your expression.

0 Karma

tpflicke
Path Finder

The confusing/awkward bit is the escaping of backslash in regular expressions, see here, in short to match a literal \ you need \\\\

Below are a couple of solutions of how to extract the basename - anything surrounding the rex clause if just test framework.

| metadata type=sourcetypes | head 1 | eval FILENAME="d:\\A\\B\\C\\D\\E\\F.dll"  | rex field=FILENAME "[a-z]:.*\\\\(?<area>\w+\.\w+)" | table FILENAME, area

| metadata type=sourcetypes | head 1 | eval FILENAME="d:\\A\\B\\C\\D\\E\\F.dll"  | rex field=FILENAME "[a-zA-Z]\:\\\\(\w+\\\\)*(?<area>\w+\.\w+)" | table FILENAME, area

Lamar
Splunk Employee
Splunk Employee

I would write this a bit differently, more importantly you seem to be missing a backslash before your word-ish chunk after your field name (?P<area>\w+\w+)

Additionally, you might get it to evaluate a bit better if you write it this way:

[a-zA-Z]{1}\:\\\w+\\\w+\\(?P<area>\w+\\\w+)

I'm not sure if that's what you're trying to extract, but you get the general idea. And maybe I'm just a creature of habit but I like to put double quotes around my regex:

index=utility sourcetype="componentcheck"|rex field=FILENAME "[a-zA-Z]{1}\:\\\w+\\\w+\\(?P<area>\w+\\\w+)"

approachct
Path Finder

No the indexer is Linux

0 Karma

Lamar
Splunk Employee
Splunk Employee

The "indexer/search head" is on Windows...yes?

0 Karma

approachct
Path Finder

Thanks, I copied your regex exactly, quotes and all, but I am still getting the below error with the suggested regex.
Error in 'rex' command: Encountered the following error while compiling the regex '[a-zA-Z]{1}:\w+\w+(?P\w+\w+)': Regex: unmatched parentheses

0 Karma
Get Updates on the Splunk Community!

Last Chance to Submit Your Paper For BSides Splunk - Deadline is August 12th!

Hello everyone! Don't wait to submit - The deadline is August 12th! We have truly missed the community so ...

Ready, Set, SOAR: How Utility Apps Can Up Level Your Playbooks!

 WATCH NOW Powering your capabilities has never been so easy with ready-made Splunk® SOAR Utility Apps. Parse ...

DevSecOps: Why You Should Care and How To Get Started

 WATCH NOW In this Tech Talk we will talk about what people mean by DevSecOps and deep dive into the different ...