How to write regex to extract different pattern of data

[seksit]

Hi everyone.

I'm new for splunk. I'm learning splunk using splunk's documents in website.

Now I'm learn to splunk scenario lesson of how to extract, when I try to extract fields called username, clientip. But the data has different pattern.

How can I write regex for this pattern?

attached is my extract fields.

Sorry for my english 🙂

[richgalloway]

This regex string should extract the user name or "invalid user x".

"for (?P<username>[\w ]+) from (?P<clientip>[^ ]+)"