Re: interactive shell detection in shrc

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Tue, 24 Sep 2024 00:10:24 +0300
    From:        Valery Ushakov <uwe%stderr.spb.ru@localhost>
    Message-ID:  <ZvHZQN0ouO82whAU%snips.stderr.spb.ru@localhost>


  | shrc is there to affect the state of a shell in a
  | way that is visible in subsequent use of that same shell.

Of course.

  | sh .shrc allows you to check that .shrc has no failures, but you cannot
  | test how it affected the shell (as opposed to sourcing it).

That's the point, to test what would happen if it were sourced,
to prevent undesired actions from affecting a real shell, before
a new version actually gets installed.

  | sh .shrc is a _non_ interactive shell

Yes, but sh -i .shrc isn't.

  | and return in the non-interacive branch is ingored,

In most shells, yes, but not all, relying on that is not portable,
and there really isn't a good reason to supply non-portable code
fragments like that.

  | so shell falls through to the interactive-only part.

which means a test intended to see what happens for non-interactive
shells doesn't show that at all, which your average user might not
understand - spending time trying to understand a "problem" which
doesn't actually exist.

Note that it is not necessarily the case that what is in that file
is only desired to effect interactive shells, I use it precisely to
add things to non-interactive shells, even more than interactive ones.

  | I would say win-win :)

I wouldn't go that far, but note I didn't actually object to making
the change, just pointing out why the code is written as it was.

kre