User-Agent strings are notorious for minor variations that make it hard to use them to categorize browsers, devices, and OS. The UA-Parser Core project maintains a giant Regex file that you can use to extract these elements.

The LUA Script found on the scripts page demonstrates the following techniques.

• How to work with YAML files
• How to use the T.re2 support by Trisul to load a dictionary of RE2 compatible Regexes

• UA-Parser Trisul script
• The UA-Parser project which maintains a library of UA Parsing regexes