topic Re: Another RegEx Question in Splunk Search

Another RegEx Question

lehrfeld — Wed, 19 Mar 2014 17:08:40 GMT

I have been engaged in an arm wresting content with Splunk for the past couple of hours with regex and it has been beating me pretty soundly. I have read the Splunk docs and looked at the various regex help sites but I can't get it working. In fact, my regex works on http://rubular.com/ just fine. But when I put it in a search is barfs.., then laughs at me.

I have weblog data and I would like to search for COMPANY\userID and place userID in a label for use down the pipeline. This is what the data looks like

2014-03-19 12:58:00 W3SVXYZ 10.0.0.1 POST COMPANY\userID 10.1.1.1 .....
2014-03-19 12:59:00 W3SVXYZ 10.0.0.1 GET COMPANY\userID 10.2.2.2 .....

I would like to extract the userID and then perform stats on them (number of concurrent users, etc).

My code so far that works in Perl is "COMPANY\\w+" but when I use it in splunk it tanks.

<base search> | rex field=_raw "COMPANY\\\w+(?<testID>)"

It does not populate the testID field correctly and it also includes results that do not have COMPANY in it.
Thanks in advance for any tips or tricks! Mike

Re: Another RegEx Question

wpreston — Wed, 19 Mar 2014 17:24:01 GMT

Try this:

<base search=""> | rex field=_raw "COMPANY\\\(?<testid>\w+)"

The parenthesis are the regex capturing group, and the expression of the items you're trying to capture must be inside the parenthesis to be extracted as the field value.

Re: Another RegEx Question

lehrfeld — Wed, 19 Mar 2014 17:34:26 GMT

Thanks for the response - Using the above regex yields an error - "unmatched parentheses" But when I place a space after the double backslash the results are not correct. It almost appears that the backslash in "COMPANY\userID" is not being found by the regex

Re: Another RegEx Question

somesoni2 — Wed, 19 Mar 2014 17:47:32 GMT

Use 3 slashes and no space.

Re: Another RegEx Question

lehrfeld — Wed, 19 Mar 2014 17:59:41 GMT

3 slashes did it! Any comment on why three are needed in this case? Thank you!

Re: Another RegEx Question

somesoni2 — Wed, 19 Mar 2014 18:48:56 GMT

To escape " , we added 1 slash. To escape that slash we added another two slashes.