topic Re: What does empty macro do? in Splunk Search

What does empty macro do?

zksplunk — Wed, 14 Aug 2024 04:15:46 GMT

Is there any difference between a empty macro with

()

I see search with both both return results but do not behave the same as

index=*

So what does these empty macro do actually? Any clues what logs or where I can further drill down this?

Re: What does empty macro do?

yuanliu — Wed, 14 Aug 2024 03:52:20 GMT

Maybe you can give more context? Where are you using any of these? If you cannot illustrate the real search command, at least post some mock code, or use index=_internal or something to demonstrate that the two are different? What is an "empty macro", anyway?

Re: What does empty macro do?

zksplunk — Wed, 14 Aug 2024 04:21:20 GMT

Thank you for your quick response. I am literally asking what does searching with exactly a pair of parenthesis with nothing inside "()" do, as many Security Content searches include an empty macro for users to add whitelist/exceptions to their search. And by default these macros are empty. At first I thought they will do nothing, but when I put one such empty macro search, it actually returns with results. I am concern if these empty macro will mess up with my searches.

Re: What does empty macro do?

yuanliu — Wed, 14 Aug 2024 04:57:59 GMT

First of all, you need to realize that () in SPL has nothing to do with "macro". Like in most languages, it is just a syntax to isolate terms. On their own, they do nothing. You will have to illustrate the context where you see behavior difference.

Let me first show you two examples:

index = _internal earliest=-2h@h latest=-1h@h

and

index = _internal earliest=-2h@h latest=-1h@h ()

They give me the exact same result.

Re: What does empty macro do?

isoutamo — Wed, 14 Aug 2024 05:18:11 GMT

If/when you have those macros on your SPL, you could expand those and see real SPL by pressing “Ctrl+Shift+e” on Windows. Then you can run those and see how those are working.