How can I get the authenticated user name under Apache using plain HTTP authentication and PHP?

How can I get the authenticated user name under Apache using plain HTTP authentication and PHP?

php apache authentication http-authentication

php

PHP_AUTH_USER not set?

php http-authentication

php

PHP CURL returns nothing

php curl http-authentication

php

How can I use Basic HTTP Authentication in PHP?

php authentication http-authentication basic-authentication server-variables

php

How to retrieve attempted $_SERVER['REMOTE_USER'] from URL when no authentication is required

php .htaccess authentication http-authentication

php

Laravel Basic HTTP Auth Check Returning False

php laravel authentication http-authentication

php