Re: [PATCH] confusing/obsolete handling of test -t operator (and doc warnings against using -o/-a)

[Chet Ramey]

On 7/8/23 3:18 AM, Stephane Chazelas wrote:
> 2023-07-07 15:52:28 -0400, Chet Ramey:
> [...]
> > Historical versions of test made the argument to -t optional here. I can
> > continue to support that in default mode for backwards compatibility, but
> > it will be an error in posix mode.
> [...]
>
> I think you may have overlooked the bottom part of my email
> (possibly because it was hidden by your MUA as it included
> quoted text) that included comments on the code and a patch.

I didn't.

> bash hasn't supported [ -t ] as an alias for [ -t 1 ] since 2.02
> and possibly earlier AFAICT since it started supporting the
> POSIX rules where [ any-non-empty-single-argument ] returns
> true, and having [ -t ] to check whether stdout is a terminal is
> not allowed.

I'm not talking about changing any of the cases that POSIX specifies. I'm
talking about the historical behavior when supplied 4 (in some cases) or
5+ arguments.

> The problem here is that some code to support that haven't been
> removed at the time the POSIX rules were implemented. The patch
> I suggested just removes that code.

I saw it.

> ksh93 does support [ -t ] when the -t is literal:

That's not POSIX conformant, so it's out.


> > > I also noticed that the fact that -a/-o were deprecated (by POSIX at
> > > least) and made for unreliable test expressions was not noted in the
> > > manual. So I suggest the patch below:
> >
> > I added some language about this, noting that POSIX has deprecated them
> > and recommending scripts not use them. Thanks for the suggestion.
> [...]
>
> Note that "(" and ")" are also obsoleted by POSIX and as a
> result any usage of test with 5 or more arguments (hence why I
> flagged them as (DEPRECATED) in the doc patch I was suggesting.

That's in there.

--
``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/