Re: . and .. are included where they were excluded before

[Chet Ramey]

On 1/25/21 4:36 PM, gregrwm wrote:

> Bash Version: 5.0
> Patch Level: 17
> Release Status: release
>
> Description:
>          . and .. are excluded from @(?|.?) in
>          bash 4.2.46(2)-release (CentOS 7.8), but are included in
>          bash 4.4.19(1)-release (CentOS 8.2) and
>          bash 5.0.17(1)-release (Ubuntu 20.04/focal).
>
>          is this change in functionality a regression, a "fix", or a new
> feature?
>          is there any option to exclude them?

We're talking about behavior that changed around ten years ago, so there's
probably no going back.

>          in all 3, .. is included in .?

Yes, basically every shell except mksh does this. The leading dot is
matched explicitly.


>          so oddly in centos7 .. is included in .? but excluded from @(?|.?)

CentOS is using a version of bash that's over ten years old.

>          and in the more recent versions it's a different inconsistency, .
> is excluded from ? ?? but included in @(?|.?)

That's the real question: whether or not `.' should match @(?|.?), even
when dotglob is enabled (and yes, both patterns have to be in there). There
isn't really any other. Since it doesn't match ? when dotglob is enabled,
there's an obvious inconsistency there, and that's what I'll look at.

>          but that's a bit askew from what actually interests me.  if i had
> my druthers, there would be an option to set so . and .. would never match
> any (sub)glob other than their literal selves (even with dotglob set).

As Kerin Millar said, you can use GLOBIGNORE for this.


--
``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/