Re: sed --posix

[Paolo Bonzini]

> My claim that sed has a bug is that you chose the first behavior without
> - --posix, and the second behavior with --posix; from the script-writer's
> perspective, we want the first behavior without --posix, but the third
> behavior with --posix.  You are correct that there is no conformance bug
> regardless of which of the three options you use.  Rather, it is a QoI bug
> in that you are not friendly to the user given the intent of what --posix
> is documented as doing.

Okay.  I see the point of implementing what you asked for.  In the
meanwhile, if you want to patch the documentation to point out the
deficiency of --posix, that's worthwhile.

>>>  My preference would be that
>>> 'sed --posix' failed with a verbose error message when undefined input
>>> like \| is detected, rather than silently changing behavior.
>>
>> This is hard, since regex does not have a flag for "fail on this
>> escape", just for "enable/disable this escape".
>
> Hard or not, that is exactly what I'm asking for.

Yes, I was just pointing out that unfortunately it's a gnulib/glibc
missing feature rather than a sed one.

Paolo