On 5/5/20 12:16 PM, Franklin, Jason wrote:
> Agreed. This is an undocumented feature, which is why Brandon and I had
> a bit of trouble figuring out what "should" happen. :/
>
>> I'm leaning towards making 0 and -0 out-of-range errors for the non-listing
>> case. This is what other shells do (the netbsd and freebsd shells being
>> notable exceptions).
>
> Well, I think 0 and -0 have different intentions as it stands.
In bash, yes. Nowhere else. They both require special handling.
> Currently, "0" indicates the command right before the "fc" invocation
> that caused the editing or listing. This shouldn't ever cause an
> infinite loop and should not be an out-of-range error, I assert.
Yes, it's equivalent to -1. That's just giving it semantics, not providing
any unique functionality. It could just as easily have been an error, as
POSIX intended.
> Example session:
>
> bash-5.0$ true # example command
> bash-5.0$ fc -l 0
> 48 true # example command
> bash-5.0$
>
> Thus, the argument in question is specifically "-0" proper. This, to
> me, means "the fc command itself" that did this work.
>
> Would a good solution be to have "0" function as-is, but have "-0" only
> be valid in the listing case? This would avoid the problem above.
This is about the only reasonable alternative.
> Of course, documenting the intent of the feature would be key to making
> the change a successful one!
I'll come up with something.
Chet
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU c...@case.edu http://tiswww.cwru.edu/~chet/
