Is it possible to run Craft CMS with putenv() function disabled? I’m using shared hosting which supports several CMS like Wordpress, Jumla, etc. In phpinfo there is putenv in disable_functions. Craft CMS needs this function to load variables from .env file. I can acces all varibales at least from $_ENV[]. 

Is there a way how I can install and use Craft CMS in this environment or is putenv(), getenv() must have?

Thanks a lot for help
DotEnv only calls putenv if it sees the function is available since version 2.4.0, so make sure you're running at least that: https://github.com/vlucas/phpdotenv/commit/58633a061610ffd731d7fbbc8f7f009d14b2e4cf

Even then, I'm pretty sure other Craft dependencies (like Composer) will still require putenv support.