[U-Boot] [PATCH 2/4] Add ctrlc_ignore environment variable to ignore Ctrl-C

[Simon Glass]

Hi Wolfgang,

On 5 June 2014 15:43, Wolfgang Denk <wd at denx.de> wrote:
> Dear Simon Glass,
>
> In message <1401992872-31985-3-git-send-email-sjg at chromium.org> you wrote:
>> Sometimes it is useful to ignore Ctrl-C, because checking for it causes the
>> CLI to drop characters. In particular for tests involving sandbox, where
>> input commands are piped in, some commands will call ctrlc() which will
>> drop characters from the test script.
>
> Why would that be the case?
>
> If this happens, I consider it a bug that should be fixed, and not
> papered over.

If you look at the code for the 'md' command it calls ctrlc() every
now and then. Each call results in a getc() which reads a character
from the console. So we lose characters.

>
>> Add a CONFIG_SYS_CTRLC_IGNORE option which enables this variable. If the
>> variable is present (e.g. "setenv ctrlc_ignore ignore") then no checking
>> for Ctrl-C will be performed.
>
> I dislike this idea. It looks wrong to me.  Can we not fix the problem
> at the root cause?

I certainly thought about this. I even though maybe we might change
the serial module to scan ahead and buffer characters, in case there
is a Ctrl-C in the future. But that itself seems like something for
the future.

Regards,
Simon