POSIX requires that the environment variables can be access as an array, through the environ variable. This array is expected to be used with POSIX interfaces s

POSIX requires that the environment variables can be access as an array, through the environ variable. This array is expected to be used with POSIX interfaces such as posix_spawn and execve. If the array already has to exist, why not use it in getenv? A purely hash-based implementation is not possible because there is putenv, and some applications expect modifications of environ to be visible via getenv.