How to get prefix of a string

I have a field with value "sv4axmaic04". I need to extract value before "axmaic". But substring "axmaic" is same/constant across all the field values. So I just need to extract value "sv4" from the given example.

Can I use dissect as below: Or any other better way
dissect {
mapping => {
"message" => "%{field1}axmaic%{field2}"

But i don't want field2 getting created here.

If you do not want field2 created then do not give it a name, just use %{}.

Another option would be to use a regexp to match the first three characters of the field

grok { match => { "message" => "^(?<field1>...)" } }


This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.