How to validate user agent?

Question

PHP

Good evening, please tell me how to properly validate HTTP_USER_AGENT.

Answer 1

What exactly do you want to check?
Perhaps this liba piwik/device-detector
will help, or something else .

Answer 2

No way. The only adequate way is to manually draw up blacklists and ban too smart ones on them.

Answer 3

https://github.com/WhichBrowser/Parser-PHP