topic split string with square brackets into individual fields in Splunk Search

split string with square brackets into individual fields

plcd63 — Thu, 13 Jan 2022 17:48:14 GMT

Hello,

I'm new to Splunk and I'm looking for some advice.

My search, e.g.

<mysearch> | table attributes

returns a value in the following format:

name[test 1]srcintf[int1]dstintf[int2]srcaddr[address1]dstaddr[dest1 dest2]service[svc1 svc2 svc3]comments[test comment here]

I would like to split the output into individual fields. The values are within square brackets, i.e.

name	test 1
srcintf	int1
dstintf	int2
...

Many thanks!

Re: split string with square brackets into individual fields

ITWhisperer — Thu, 13 Jan 2022 18:42:15 GMT

| rex "name\[(?<name>[^\]]+)]srcintf\[(?<srcintf>[^\]]+)]dstintf\[(?<dstintf>[^\]]+)]srcaddr\[(?<srcaddr>[^\]]+)]dstaddr\[(?<dstaddr>[^\]]+)]service\[(?<service>[^\]]+)]comments\[(?<comments>[^\]]+)]"

Re: split string with square brackets into individual fields

plcd63 — Fri, 14 Jan 2022 10:53:35 GMT

Thank you! This works, unless one of the fields is empty, e.g. comments[], which is very likely to happen on some of them, depending on the user input provided.

Re: split string with square brackets into individual fields

ITWhisperer — Fri, 14 Jan 2022 11:01:42 GMT

| rex "name\[(?<name>[^\]]*)]srcintf\[(?<srcintf>[^\]]*)]dstintf\[(?<dstintf>[^\]]*)]srcaddr\[(?<srcaddr>[^\]]*)]dstaddr\[(?<dstaddr>[^\]]*)]service\[(?<service>[^\]]*)]comments\[(?<comments>[^\]]*)]"

Re: split string with square brackets into individual fields

plcd63 — Fri, 14 Jan 2022 15:35:09 GMT

To take this step further, could I also use rex if not every time all of the values are part of the reported field?

e.g. my 1st search might return:

name[test 1]srcaddr[address1]

my second search:

nsrcintf[int1]dstintf[int2]srcaddr[address1]comments[test comment here]

my third search:

comments[test comment here]

etc...

Re: split string with square brackets into individual fields

ITWhisperer — Fri, 14 Jan 2022 16:05:06 GMT

Yes, and sometimes you need to do this if your events don't have all the anchor strings - if this is the case, none of the fields are extracted if you use a single rex string i.e. there has to be a complete match for anything to be extracted. This is useful in some instances and not so much in others, but tbh, it is better this way around in the majority of cases.