Re: posix command search and execution

[Chet Ramey]

On 11/8/23 6:40 PM, Mike Jonkmans wrote:
> On Wed, Nov 08, 2023 at 11:52:19PM +0700, Robert Elz wrote:
> >      Date:        Tue, 7 Nov 2023 23:04:10 +0100
> >      From:        Mike Jonkmans <bashbug@jonkmans.nl>
> >      Message-ID:  <20231107220410.GC27780@jonkmans.nl>
> >
> >    | It makes sense to partition the builtins in three categories with
> >    | a separate name for each.
> >
> > That's more or less what has been done now, with the specials, intrinsics,
> > and regular builtins.
>
> A step in the right direction.
> In 30 years or so we may lose the special builtins ;)

Special builtins are here to stay in POSIX.

> >    | Are scripts in /etc/profile considered part of the implementation?
> > So, no, I don't think so.
>
> I don't want to start a flame war, but Chet thought it was. :)

It depends on who supplies /etc/profile, doesn't it? If it comes as part
of the distro, whoever it is, it's part of the "implementation."

If the system with the /etc/profile as distributed is what undergoes
POSIX certification (hypothetically), then it's certainly part of the
implementation.

I don't think something admin-installed is part of the "implementation."


> > Yes, but the point is that this isn't what the standard says, more like
> > what it really should say.   This PATH search for builtins stuff is an
> > invention by people trying to force something upon shells that none of
> > them implemented, because they thought it would be better.
>
> Ouch.

The standard developers at the time made a decision to prioritize third-
party developers (script writers) over shell implementors, invented
something they thought would do that, didn't specify anything concrete,
and expected the shell implementors to do something "because it's in the
standard." Implementors basically told them to pound sand.

Chet
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/