From: Dave Anderson <anderson@xxxxxxxxxx>
Subject: Re: Usage Advice
Date: Fri, 2 Oct 2009 09:47:38 -0400 (EDT)
>
> ----- "CAI Qian" <caiqian@xxxxxxxxxx> wrote:
>
>> Hallo!
>>
>> There are a few things that bother me the most regards the crash utility
>> usages.
>>
>> 1) Pointer remains at the beginning after the UP array key. When
>> entering the UP array key, it repeats the last command like,
>>
>> crash> struct struct_tss
>>
>> However, then the current position remains at the beginning. It is
>> usually unlike in bash that the current position remains at the end,
>> so it is easier to update the command like,
>>
>> crash> struct struct_tss ffffffff819f1764
>
> I believe that's a function of the readline library, and there may be
> a setting/binding that could be used to make that happen. Since the
> beginning, readline has been set up by crash like this:
>
> if (STREQ(pc->editing_mode, "vi")) {
> rl_editing_mode = vi_mode;
>
> rl_bind_key(CTRL('N'), rl_get_next_history);
> rl_bind_key(CTRL('P'), rl_get_previous_history);
>
> rl_bind_key_in_map(CTRL('P'), rl_get_previous_history,
> vi_insertion_keymap);
> rl_bind_key_in_map(CTRL('N'), rl_get_next_history,
> vi_insertion_keymap);
>
> rl_generic_bind(ISFUNC, "[A", (char *)rl_get_previous_history,
> vi_movement_keymap);
> rl_generic_bind(ISFUNC, "[B", (char *)rl_get_next_history,
> vi_movement_keymap);
> }
>
> if (STREQ(pc->editing_mode, "emacs")) {
> rl_editing_mode = emacs_mode;
> }
>
> I don't recall where those bindings came from -- I copied them from some
> other program. I'm guessing that there's a binding that would put the cursor
> at the end of the recalled string, but I don't know what it is off-hand.
>
> If anybody knows what the binding sequence is, please post it here...
>
> On the other hand, when updating a command string, I guess it depends
> whether the location you want to change is at the beginning or the end
> of the string would be a cause to be bothered by it?
>
Yes, but from the familiarity point of view, I vote for at the end like
in Bash.
>>
>> 2) Pressing PgUp/PgDn when input leads nothing can be input. This
>> happens like,
>>
>> crash> log
>>
>> In order to see the full log output, I may press PgDn several
>> times. However, if continue pressing the key after the output has
>> already finished like,
>
> In the case of the "log" command, the PageUp and PageDown keys are being
> captured by the scrolling routine, which is /usr/bin/less by default.
>
OK.
>>
>> crash>
>>
>> there seems no way to input anything unless pressing Enter several
>> times until reach the next prompt.
>
> Right -- PageUp and PageDown don't make sense once you are back to
> the "crash> " command prompt.
>
>> 3) Ctrl-C is not working to cancel the current input. GDB has the same
>> problem. It needs to press Ctrl-C several times to get it to a new
>> prompt.
>
> That's also done on purpose -- in certain circumstances it requires
> that Ctrl-C be hit 3 times (MAX_SIGINTS_ACCEPTED). There was a good
> reason that was put in place, but I'm afraid I don't recall why...
>
OK.
Thanks!
CAI Qian
--
Crash-utility mailing list
Crash-utility@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/crash-utility
