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Assistance needed for a cleaner regex approach on field with variable content

msarro
Builder

Hi everyone. I am trying to parse SIP dialogs using splunk.
Inside the dialog messages, there are TO and FROM lines. They can appear in any of the following formats:

What I am looking to get out of this is the content within the angle brackets. In cases where it is in the format of a URI (somestring @ someotherstring), I only want somestring to be captured. So for the first four examples 18005551212/unavailable/anonymous would be returned.

In the case where the format is just a FQDN, I need the full fqdn captured.

Right now I am using this methodology:

|rex field=_raw "From:.*\(LESSTHAN)sip:\+?(?(LESSTHAN)FROM_NUM(GREATERTHAN).*)@.*\(GREATERTHAN).*" 
|rex field=_raw "From:.*\(LESSTHAN)sip:\+?(?(LESSTHAN)FROM_DOM(GREATERTHAN)(\w+\.)+\w+);?.*\(GREATERTHAN).*" 
|eval FROM_FIELD=coalesce(FROM_NUM,FROM_DOM)

(Please replace the (GREATERTHAN) and (LESSTHAN) with the correct angle brackets since the splunk answers parser has trouble understanding them)

This works but I'm hoping there is a cleaner way to do this without needing multiple regexes and an eval statement for what is essentially the same field. Any suggestions would be very much appreciated - as it stands I'll have to do 6 different operations to get the values of just 2 fields which is rather expensive processing-wise.

Tags (1)
0 Karma

jonuwz
Influencer

off the top of my head :

| rex "From:.*?<sip[:+]+(?<FROM_FIELD>[\w.]+)"

so thats :

"From:" followed by any number of characters up to the 1st "<sip"
Then 1 or more of : or +
Then we capture as many word characters (A-Z a-z 0-9 _ ) or "." as we can and put it in the FROM_FIELD

0 Karma
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