[U-Boot-Users] Delete all env vars except read onlys

Markus Klotzbücher mk at denx.de
Wed Feb 13 13:55:26 CET 2008


Detlev Zundel <dzu at denx.de> writes:

>> Stefan Roese <sr at denx.de> writes:
>>
>>> On Wednesday 13 February 2008, Markus Klotzbücher wrote:
>>>> > => scrubenv
>>>> > Do you really want to do this ('yes' or 'no')? yes
>>>>
>>>> Such a confirmation is not very Unix-like and will prevent this command
>>>> to be used in scripts. I like the idea of a scrubenv/resetenv command
>>>> but vote for leaving out the confirmation.
>>>>
>>>> U-Boot provides many, much more serious ways to blow you foot off which
>>>> don't ask such questions.
>>>
>>> Sure. But not by "just" typing one command. Or at least I don't know those 
>>> kind of destructive commands.
>>
>> It need not be a single one, it could be a script. For instance, I once
>> ran an "update" script without checking that _my_ version of U-Boot
>> would be used. It used some ancient version which turned the board
>> (temporarily) into a doorstop.
>>
>> Stupid? Yes! But would such checks (e.g. to "mw") have avoided the
>> problem?  I doubt it. Probably I'd just have typed "yes" without
>> checking.
>>
>> BTW, after accidentally erasing the environment variables U-Boot will
>> (likely) still start up, so it's really not that critical, is it?
>
> Why not do both?  Unix untilities do it sometimes this way: Use an
> interactive check for "scrubenv" but allow "scrubenv -force" not to
> ask.  As many of the U-Boot users know Unix, this would follow from the
> "principle of least surprise"...

Yeah, why not both. That's fine with me!

Best regards

Markus Klotzbücher

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