From: Chet Ramey
Subject: Re: GLOBIGNORE
Date: Mon, 4 May 2026 15:27:22 -0400
>On 5/2/26 5:46 PM, Stan Marsh wrote:
>>BTW, maybe it is one of those things where the variable is "magic" and
>>the implementation is such that the magic happens as a side effect of
>>the variable being set. In the case where it is not explicitly set
>>by the current shell process (because it was inherited from the
>>environment), the magic doesn't happen.
>Kind of. GLOBIGNORE changes behavior, so the internal data structures
>that control that are modified when the variable is set or unset.
>GLOBIGNORE has been around 30+ years (I implemented it in 1995 and it
>first appeared in bash-2.0), and I can't recall my thought process
>from back then. It may be that I didn't want one process to be able
>to affect another like that (since GLOBIGNORE is ignored when the shell
>is in privileged mode) but I can't remember. What I can say is that it's
>never been inherited from the environment in that way.
>Chet
OK. Just a few more comments about this:
1) It sounds like it is working as designed, but I think the doc
should be updated to be more explicit about this. Note,
incidentally, that you can also demonstrate this from tcsh, like
this:
% setenv GLOBIGNORE 'Foo_0*'
% bash
$ : Observe that GLOBIGNORE is not active, unless/until you do:
$ : GLOBIGNORE="$GLOBIGNORE"
2) This all came about in the course of something I was working on
where I needed the functionality of GLOBIGNORE, which I had never
used before. In doing the usual preliminary testing of it, I
could not get it to work and thought maybe it just never actually
got implemented. Eventually, I figured out that it could not work
in the expected way (i.e., GLOBIGNORE=... echo Foo*), so ended up
trying the "run a new copy of bash" thing to see if that works and
when that didn't work, concluded that it just really doesn't work.
As mentioned in my previous post, the "eval trick" is a good way
to get to where one wants to be.
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