Let’s walk through how to extract meaningful fields like IP address, port, error level, and message content from a raw PHP warning log using regular expressions and Splunk’s rex command. Step 1: The Raw Log Here’s a sample of the raw log we’re working with: [client 104.23.211.100:21636] PHP Warning: Cannot assign an empty string to a string offset in /www/website.com/httpdocs/wp-includes/user.php on line 41 From this log, we want to extract: IP Address Port Error Level (e.g., Warning, Notice, etc.) Full message content after the error level Step 2: Crafting the Regex Pattern We used regexr.com to help test and refine our regular expression. After experimenting,Read More →