Because we dont always know if $_ENV is available

Habitat is a light weight wrapper over PHP's environment variable functionality. Habitat allows the retrieval of all environment variables when the ini setting variables_order does not contain the E flag

Habitat delegates most functionality to the native php functions getenv and putenv. If $_ENV is not available due to the variables_order ini setting, then Habitat's getAll method will still allow access to all variables that are in $_ENV.

use Habitat\Habit;

//equivalent of getenv('FOO')
$foo = Habitat::getenv('FOO');

//equivalent of putenv('FOO=BAR')
$wasSet = Habitat::putenv('FOO=BAR');

/**
 * Returns $_ENV if set, otherwise set $_ENV via phpinfo() and
 * return it
 */
$all = Habitat::getAll();

Habitat can support the cli and html varieties of phpinfo. It will detect the current sapi and use the appropriate method to populate $_ENV