getenv vs ENV in PHP

Question

What is the distinction between $_ENV and getenv()?

Any disadvantages to utilizing either one?

When I require something, getenv() occasionally provides it when $_ENV does not (such as HOME).

Answer 1

They are identical, according to the getenv documentation for PHP, with the exception that getenv searches for the variable while operating on case-insensitive file systems (like Windows). It continues to function as case-sensitive on Linux hosts. It probably won't matter most of the time, however, one of the comments on the documentation explains:

For example on Windows $_SERVER['Path'] is like you see, with the first letter capitalized, not 'PATH' as you might expect.

Because of this, unless you are certain about the case of the environment variable you are trying to retrieve, I would usually choose to use getenv to optimize cross-platform behaviour. 

I hope this helps you.