[RFC] Make getenv O(1)

[Alexander Monakov]

On Fri, 18 Oct 2013, Ondøej Bílka wrote:
> You could argue that this does not help when likely case is that
> variable is not defined. For that I would need posix say that changing
> variable name via environ pointers is illegal.

Indeed; I would also ask if such functions are allowed to query interesting
environment variables once on first call and then cache the result (similar to
how the dynamic linker stashes initial LD_LIBRARY_PATH on the side and calls
to dlopen do not check the environment again).

Alexander