[U-Boot] HUSH logical AND/OR expressions

[Joe Hershberger]

Hi James,

On Tue, Apr 28, 2015 at 2:13 PM, James Chargin <jimccrown at gmail.com> wrote:
> Dear Joe,
>
> On 04/28/2015 11:35 AM, Joe Hershberger wrote:
>>
>> Hi James,
>>
>> On Tue, Apr 28, 2015 at 1:19 PM, James Chargin <jimccrown at gmail.com>
>> wrote:
>>>
>>> Dear Joe Hershberger,
>>>
>>> On 04/28/2015 11:00 AM, Joe Hershberger wrote:
>>>>
>>>>
>>>> Hi Joakim,
>>>>
>>>> On Mon, Apr 27, 2015 at 8:39 AM, Joakim Tjernlund
>>>> <joakim.tjernlund at transmode.se> wrote:
>>>>>
>>>>>
>>>>> Trying to get a better handle of HUSH shell expressions, this does not
>>>>> work as I expect:
>>>>> => false && true || echo ECHO
>>>>> => false && false || echo ECHO
>
>
> ...
>
>>
>> I always just assumed this was a limitation of hush, but it's now
>> looking like a bug instead.
>>
>> I haven't debugged into it, but I tend to stay away from hush these
>> days. When I've submitted a bug fix to this area I've been told that
>> we should upgrade wholesale instead, and I've haven't been up for that
>> task so far.
>> http://lists.denx.de/pipermail/u-boot/2012-November/139841.html
>
>
> That's a great conversation with Wolfgang, thanks for the reference.
>
> Like you, I have tended to use hush carefully. It is similar to sh/bash, but
> different enough that I never count on an easy port of bash script
> fragments.
>
> I noticed you asked for a reference to the original hush code that is the
> origin for U-Boot's adaptation. I couldn't find a reply to that question. I
> also haven't been able to find anything with a quick we search. Do you know
> where it did come from?

I never got a response, but it appears to be busybox...

http://git.busybox.net/busybox/tree/shell/hush.c

>>
>> Perhaps there is an easy, minor bugfix for this that would be
>> palette-able.
>
>
> I've been "afraid" of the hush code for a while. I don't think I want to
> mess with it now. I'll just continue to work with what we've got, carefully.
>
> Thanks again for your attention,

No problem...

Cheers,
-Joe