3.15.1.10 env
env(string $key)
Gets an environment variable from available sources. Used as a backup if $_SERVER or $_ENV are disabled.
This function also emulates PHP_SELF and DOCUMENT_ROOT on unsupporting servers. In fact, it's a good idea to always use env() instead of $_SERVER or getenv() (especially if you plan to distribute the code), since it's a full emulation wrapper.
