Confirm accuracy of required extensions

[johnbillion]

The list of required extensions originated at https://github.com/cftp/WP-Extension-Check.

I don't believe the filter extension is actually required to run WP, but it's certainly required to run some popular plugins such as Yoast SEO.

Are all the other "required" extensions accurate?

[jdevalk]

Core doesn't require libxml either I think. We do.

[johnbillion]

sockets is probably no longer required since Requests was merged in.

[danielbachhuber]

See also https://github.com/ataylorme/WordPress-Hosting-Best-Practices-Documentation/blob/master/server-environment/server-environment.md#php-extensions

It might be nice to have aforementioned document link to the specific usage.

[swissspidy]

Core doesn't require libxml either I think. We do.

Core uses libxml for some stuff if it is available, e.g. XML oEmbed responses.

[johnbillion]

It turns out there is a core list: https://make.wordpress.org/hosting/handbook/handbook/server-environment/#php-extensions

This list is used in WP_Site_Health::get_test_php_extensions() in the new Site Health functionality in 5.2, unfortunately not very well abstracted.

[danielbachhuber]

It turns out there is a core list:

I think the core list is simply a published version of https://github.com/ataylorme/WordPress-Hosting-Best-Practices-Documentation/blob/master/server-environment/server-environment.md#php-extensions

Which I put together originally. To the best of my knowledge, and may not be 100% accurate.