Re: standards/42828: Almquist shell always evaluates the contents of ${ENV} even if non-interactive

[Richard Hansen <rhansen%bbn.com@localhost>]

Robert Elz wrote:
> In particular, with this being a significant change, it is definitely 
> not suitable for a pullup to NetBSD 5 (or any existing released system).

Agreed.

> On the other hand, 
> if ${ENV} isn't run when *every* shell starts, what is?   If there's 
> nothing, ten all that's left is what's in the environment to tailor 
> the shell, and not everything can be done there, and even when it can, 
> passing around all kinds of shell specific noise in the environment, to 
> every process that runs, isn't a sane way of operating.

I agree that the POSIX design is suboptimal, but at this point there is 
greater value in being compatible than in being right.

Cross-platform scripts can't rely on NetBSD's nonstandard behavior, so 
they won't take advantage of it.  NetBSD-targeted scripts that require 
the nonstandard behavior would be better served by an extension 
specifically for that purpose (e.g., dot ~/.nbshrc upon every shell 
invocation).

It would be unfortunate if an ordinary script ran everywhere except NetBSD.

> What's more, "ENV" is the name of the env var that sets the startup 
> script for everthing that's a basically Bourne compatible shell (though 
> that shell had no similar concept, of course) - but not all shells are 
> the same,  and stuff that fits one shell won't fit.  The effect of this
> is that it isn't sane to put just any random script as $ENV,

These are arguments for standards compliance, not against.

> I'd put this pack the way it was.   Screw POSIX in this case.

I think it should be kept, just not pulled into netbsd-5* in order to 
minimize surprises.  Fixing this bug might raise some issues, but I 
believe the long-term benefit from standards compliance will outweigh 
the short-term pain.

-Richard