Re: unset does not remove functions like a[b] unless -f is specified

[Chet Ramey]

On 2/3/23 6:55 PM, Robert Elz wrote:

>    | However, bash allows,
>    | and has always allowed, function names to contain slashes when running in
>    | default mode. This has been true for over 30 years.
>
> I never knew that, and I've been using bash probably all of that time.

OK.

>    | It's kind of redundant, since POSIX doesn't allow the application to have
>    | function names that contain slashes in the first place.
>
> Well, kind of - a portable application cannot assume that function names
> that are not "name"s will work - but the shell is allowed to support more
> than that:
>
>         An implementation may allow other characters in a function name
>         as an extension.
>
> and if the application knows that the implementation permits it, 

Sure. There's just no portable way to find out. You have to rely on extra-
standard mechanisms.


> But a posix conforming shell will still never execute a function that
> has a '/' in its name, even if it has extended the character set for
> function names, and allows '/' in that set. 

Yep. I'll probably change that.

>    | Earlier versions of the standard required the function name to be a NAME,
>    | while acknowledging extensions were possible.
>
> It still does. 

In a different way. The original versions offered no wiggle room: "fname
... shall be a name." Post-2001 versions shifted the burden: "the
application shall ensure that it is a name." Implementations could offer
other characters, but the standard in place when I added posix mode
required a function name to be a name, so that's what bash enforced. This
is 1992 or thereabouts, remember.


> The point of all of this is that if all shells started adopting a MUCH
> wider character set for function names, perhaps the next revision of the
> standard (not the one coming next year or whenever - but the one after
> that, Issue 9, perhaps in the mid or late 2030's [I am guessing]) might
> be able to alter the definition so the function name is just a word, rather
> than a NAME, ie: the same syntax as a command-name in a simple command.

"But a man's reach should exceed his grasp, or what's a heaven for?"

Bash already allows that much wider character set, with a couple of
documented exceptions that have been around since 1988. It seems like
most shells don't, according to your previous message. It's time for them
to catch up.

--
``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/