Re: Environment variables

[kilgallen@eisner.decus.org (Larry Kilgallen)]

In article <55kmb1$3m6@top.mitre.org>, mfb@mbunix.mitre.org (Michael F Brenner) writes:
> Larry Kilgallen said:
>     > The particular example of
>     > "environment variables" does not make sense outside Posix/Unix, so those
>     > who have been bitten once by a portability issue should consider future
>     > porting requirements as well.
> 
> It might be good to consider that environment variables make sense in DOS,
> DOS with PharLap extender, DOS with Desqview extender, DOS with Desqview/X
> extender, Windows NT, OS/2, VxWorks, and other operating systems. Are there
> any operating systems or remote target (embedded) runtime systems that 
> do not provide environment variables?

VMS, MacOS and MVS do not have "environment variables" with their
native user environments.  Naturally they all have them in their
Posix environments (or Unix emulators).  But some requirements
may preclude running within those Posix/Unix subsystems.

Naturally all these operating systems have something "just as good
as" environment variables, but all subtly different.  In the case
of VMS, both the logical name mechanism and the DCL symbol mechanism
have some of the qualities of environment variables, but neither is
an exact match.

Are you sure that the non-Unix operating systems listed all ascribe
semantics to "environment variables" which have the same meaning and
scope as those for Unix ?  Certainly the goal is not to access just
any construct an operating system vendor might have named "environment
variables".

Larry Kilgallen