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

[Koichi Murase]

2023年2月4日(土) 11:12 Chet Ramey <chet.ramey@case.edu>:
> > 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.

I disagree with making the change to disallow the execution of
functions with a slash in their names. First, this breaks backward
compatibility. As I have mentioned in another reply, I'm using slashes
in function names everywhere in my Bash scripts (of course, which is
not the POSIX shell scripts). As I am using slashes for namespacing,
almost all the shell functions in my shell library contain slashes in
their function names. This might be a personal thing, but I'm really
unhappy if this incompatible change is made. Anyway, I don't think
there is a good reason to break backward compatibility for the feature
that Bash had from the very beginning.

Also, if a script is intended to be a portable POSIX-shell script, the
script will never attempt to define a shell function that has slashes
in its function name. So, even though Bash runs the functions whose
names contain slashes, it doesn't change any behavior of the portable
POSIX-shell scripts. The functions that have slashes in their names
are Bash extensions. Is Bash required to strictly follow the POSIX
standard even for non-POSIX shell scripts that use Bash extensions?

For compatibility among shell implementations, Zsh also seems to
support the execution of functions with a slash in their names, though
Yash doesn't seem to attempt to run such functions. Also, it seems no
one has pointed out this incompatibility with the standard for more
than thirty years, which implies that no one including the POSIX
people hasn't paid much attention to these detailed behavioral
differences.  I feel this is just an issue of the wording of the
standard and its interpretation. Is it impossible that this is
explicitly marked as `unspecified' in the standard?

--
Koichi