I’ve found LogParser tool to be very useful for querying log files especially whenever I am required to analyze the IIS log files. You can download LogParser from here.
In this example, I’ll be querying multiple Log files unique users with Windows Authentication visiting the site. Click on the icon “Choose Log files/folders to query” and Add all files which you want to search. Open a New Query window and in the Query editor, enter the below query:
SELECT DISTINCT cs-username FROM '[LOGFILEPATH]'
This works much like SQL queries where IIS log headers work like columns. The above query will simply return distinct users visiting the site. Make sure the Log Type selected is W3CLOG.
If you want to Output all the data to a .csv file, then you can use the below query:
SELECT SELECT DISTINCT cs-username INTO '[OUTFILEPATH]users.CSV' FROM '[LOGFILEPATH]'
You can check the default export directory where the file is created. It should be something like this “C:\Users\<username>\AppData\Roaming\ExLPT\Log Parser Studio\Output”.