Re: what does 'interactive' mean?

[Bart Schaefer <schaefer@brasslantern.com>]

On Tue, Aug 10, 2021 at 3:38 PM Ray Andrews <rayandrews@eastlink.ca> wrote:
>
> The only thing I'd  even want to know is how when where and
> why I'd ever want to get involved with the issue with very practical
> examples.

There are only two reasons I can think of why you would care:
(1a) The /etc/zshenv file is read in all shells, and you're a system
administrator who wants to do (or not do) something only in shells
that are also (or are not) going to read the zshrc files.  The classic
example would be some adjustment to $PATH.
(1b) You're a user with the same go/no-go concern about something in
your .zshenv file.
(2) As (1ab) except for zlogin/zlogout files (yes, there are
circumstances in which a login shell might not be interactive, mostly
with remote shells).  The example here would be to modify any of the
history-related variables.

I suppose a third case would be that you're intending to forcibly
create one of the foregoing circumstances by turning the INTERACTIVE
option explicitly on or off.  Examples of why you're doing that would
be pretty obscure.