Grok - extract file extension from file name

Elastic Stack Logstash
1

Hi,

I have problems with creating a grok filter to extract the file extension from the file name field.

Example data:
9151_to_9152.log
80bddb9998f9f66bc44b59d9899bbbb853b8958ecd9188e14fd0828e00246050.txt ($FILE_NAME)

I tried:
(.(?[^./]+))

But I don't want to have "($FILE_NAME)"...only the file extension.

Thanks!

2

(.(?[0-9A-Za-z]*))

3

Hm...but here is it still not working:

Apps - Process All.pas.0001.bak

Any idea?

4

Make sure you escape the period and add a $ anchor at the end so you only match alphanumerical sequences at the end of the string.