Stephane Chazelas <stephane.chaze...@gmail.com> wrote:
> 2018-04-17 16:24:09 +0200, Joerg Schilling:
> [...]
> > > This behaviour is, frankly, utterly broken and I'm astonished that
> > > any shell author would think it was a good idea.
> >
> > In your specific example, it looks incorrect. In many other cases, it seems
> > to
> > be helpful.
> [...]
>
> Can you please give an example where it could be useful?
e.g. in all cases where the string you are looking for is a "bad pattern".
> IMO, it should be (remain) treated as a bug/misdesign of
> Bourne/ksh88.
Since I am sure that the implementation is exactly the way it is by intention
(We may try to ask Stepehn Bourne ;-) but he did not work on the shell since at
least 35 years. I believe it is to make looking for "bad pattern" easier.
> Note that, as I said earlier ksh (88 and 93) doesn't do it for
> [[ string = pattern ]], so presumably, it only does it for
> backward portability with the Bourne shell (it's even possible
> David Korn hadn't realised the Bourne shell was doing that and
> just inherited the code).
But this is not part of POSIX.
Maybe this is a question to ask David Korn for.
> > If you do not like to make existing behavior of the reference
> > implementations
> > incorrect, there needs to be a better solution for the problem you mention.
>
> To work around that bug/misfeature, one would have to do:
>
>
> case $answer in
> "[0-9]") echo KO;;
> [0-9]) echo OK;;
> *) echo KO;;
> esac
So, thank you.
There is a way to deal with this kind of behavior.
Jörg
--
EMail:jo...@schily.net (home) Jörg Schilling D-13353 Berlin
joerg.schill...@fokus.fraunhofer.de (work) Blog: http://schily.blogspot.com/
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