[Crash-utility] Re: paging command [was Re: crash CPU bound waiting for user response]

[Dave Anderson]

D. Hugh Redelmeier wrote:
> [I hope that you don't mind my jumping in with both feet.  I think
> that fresh eyes are valuable.  After a short time one gets used to
> things and no longer notices what would newbies stumble over.]
> 
> | From: Dave Anderson <anderson at redhat.com>
> 
> | D. Hugh Redelmeier wrote:
> | > | > ==> It does not say in what way the terminal is not fully functional.
> 
> | > It seems to be coming from /usr/bin/less.
> 
> | Based upon running within that emacs/Jove environment I guess?
> 
> Based on $TERM ("vanilla") and the corresponding termcap or terminfo
> entry.  To see this, try:
> 	TERM=vanilla less /etc/fstab
> 
> | > The code in main.c:setup_environment ought to use the PAGER
> | > environment variable if it is defined.
> 
> | I prefer not to change the default behaviour based upon the
> | user's PAGER variable.
> 
> The PAGER variable is a UNIX/Linux convention.  Not too well
> documented, but real.  Kind of like EDITOR and VISUAL.
> 
> Now that I know how to avoid the problem, I don't care much for my own
> sake.
>

Good...

> | Yeah, the man page is pretty simple-minded.  As you can see, I didn't
> | write it, preferring to keep crash usage documentation self-contained
> | within the utility itself.
> 
> Man pages are another good and longstanding UNIX/Linux tradition.
>

Thanks for the lecture.  I understand PAGER, and what man pages are as
I worked solely in the UNIX world since 1981 until I was forced into
the Linux domain...  ;-)

> At a minimum, the man page should say that it is incomplete and that
> the definitive documentation is the help command.  It should also have
> a FILES section to point out  ~/.crashrc.

Nobody's complained until you did -- please send a patch with what you'd
like to see.

> 
> 
> BTW, I tried
> 	set edit emacs
> and got
> 	set: cannot change editing mode during runtime
> 
> I don't think that it would be hard to fix this:
> 
> - in cmdline.c:readline_init, change all calls to rl_bind_key to be
>   calls to rl_bind_key_in_map using the vi_movement_keymap keymap.
>   This way the emacs map won't get damaged.
> 
>   Move these binding commands out of the "if" -- they need to be
>   executed unconditionally.
> 
> - each time where you would print the error message "cannot change
>   editing mode...", just do change it (i.e. change rl_editing_mode and
>   pc->editing_mode).
> 
>   Is there a reason to have a pc->editing_mode?  Could rl_editing_mode
>   suffice?
> 
> Note: I have not tested this and I've never programmed any readline
> calls, so I might well be missing something.

It's been way too long, I'm sure I don't remember.  If you've
not figured it out by now, I'm not an emacs user...

When you've tested it out, please send us a patch.

Thanks,
   Dave