[Crash-utility] The "ctrl + c" doesn't work in crash

[Lei Wen]

Hi Dave,

> -----Original Message-----
> From: crash-utility-bounces at redhat.com
> [mailto:crash-utility-bounces at redhat.com] On Behalf Of Dave Anderson
> Sent: Thursday, March 15, 2012 9:31 PM
> To: Discussion list for crash utility usage, maintenance and development
> Subject: Re: [Crash-utility] The "ctrl + c" doesn't work in crash
> 
> 
> 
> ----- Original Message -----
> > Hi Dave,
> >
> > I found the "ctrl + c" doesn't work well in crash. Sometimes, we may
> > type a wrong command and want to directly cancel it by "ctrl+c" like
> > in the bash. But this combination only do seldom response, what I
> > mean is I once see it works once or twice.
> >
> > I also notice there was a mail thread talking about it:
> > http://www.redhat.com/archives/crash-utility/2009-October/msg00006.html
> >
> > But on the most new crash 6.0.4, simply ctrl+c three times or more
> > would not lead to a new prompt...
> 
> SIGINT's are always caught, and it depends upon whether the command is
> currently being fed into the scroller, and in some cases, the command
> itself.  See the callers of received_SIGINT() for example.

I see...
And while I redo the test, I can see SIGINT work again, prompt the input > when type three ctrl+c. No idea why previous ctrl+c not working...

I still get a another display issue regarding the ctrl+c.
I use the "log" command to show the kernel dmesg, and always the message buffer is large which cannot be displayed in one screen. So I could see the below notice in the foot of the screen:
-- MORE --  forward: <SPACE>, <ENTER> or j  backward: b or k  quit: q

If I type "ctrl+c" when the message still not get fully displayed, eventually I would see the previous only one foot notice would show up several and keep growing.
Like this:
[  413.741638] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[  413.749725] pgd = d3e90000
[  413.752441] [00000000] *pgd=12109831, *pte=00000000, *ppte=00000000
 -- MORE --  forward: <SPACE>, <ENTER> or j  backward: b or k  quit: q
 -- MORE --  forward: <SPACE>, <ENTER> or j  backward: b or k  quit: q
 -- MORE --  forward: <SPACE>, <ENTER> or j  backward: b or k  quit: q

And when this abnormal happens, the <space> would be displayed normally as before, but when the whole message is drained out, the console prompt would not be displayed. And each <enter> after this abnormal, would lead to another such notice to be showed up like the message buffer itself.

So is it a bug for the cmdline handling?
> 
> Dave
> 
Thanks,
Lei