Pager does work from a menu?

Pager does work from a menu?

[adrian15]

This code from: normal/command.c

   /* Enable the pager if the environment pager is set to 1.  */
   if (interactive)
     pager = grub_env_get ("pager");
   else
     pager = 0;
   if (pager && (! grub_strcmp (pager, "1")))
     grub_set_more (1);

Can anyone confirm my suspictions that even the pager variable set to 1
there is NO stop on the screen when running a grub option that has the
cat command inside it with a big file?

I am suspecting because in grub legacy there was the same stupid
behaviour which I fixed of course.

I also do not like the way that pager is run. I mean, putting a getkey
inside the

void
grub_putcode (grub_uint32_t code)

function from: kern/term.c

it seems to me a bit childish although I do not know so far a better
solution.



adrian15

Re: Pager does work from a menu?

[Robert Millan]

On Tue, Jun 12, 2007 at 01:57:42PM +0200, adrian15 wrote:
> This code from: normal/command.c
> 
>   /* Enable the pager if the environment pager is set to 1.  */
>   if (interactive)
>     pager = grub_env_get ("pager");
>   else
>     pager = 0;
>   if (pager && (! grub_strcmp (pager, "1")))
>     grub_set_more (1);
> 
> Can anyone confirm my suspictions that even the pager variable set to 1
> there is NO stop on the screen when running a grub option that has the
> cat command inside it with a big file?

Can you ellaborate?  From the code you pasted, I just see that when
"interactive" is set to 0, this has the same effect as pager being set to
the "0" string.

(btw, this pager = 0 assignment looks a bit confusing; I changed it to NULL
altogether with the other two I spotted earlier)

> I am suspecting because in grub legacy there was the same stupid
> behaviour which I fixed of course.
> 
> I also do not like the way that pager is run. I mean, putting a getkey
> inside the
> 
> void
> grub_putcode (grub_uint32_t code)
> 
> function from: kern/term.c
> 
> it seems to me a bit childish although I do not know so far a better
> solution.

Please try to tear down that language!  "stupid" and "childish" are in general
not very appropiate words for a development list.

I suppose you're referring to:

          grub_printf ("--MORE--");
          grub_setcolorstate (GRUB_TERM_COLOR_STANDARD);

          key = grub_getkey ();

What do you find wrong in this code?  AFAICS, the message is printed and then
we use grub_getkey to block untill a key is pressed.  Sounds like normal
pager-ish behaviour to me..

-- 
Robert Millan

My spam trap is honeypot@aybabtu.com.  Note: this address is only intended
for spam harvesters.  Writing to it will get you added to my black list.

Re: Pager does work from a menu?

[adrian15]

Robert Millan escribió:
> On Tue, Jun 12, 2007 at 01:57:42PM +0200, adrian15 wrote:
>> This code from: normal/command.c
>>
>>   /* Enable the pager if the environment pager is set to 1.  */
>>   if (interactive)
>>     pager = grub_env_get ("pager");
>>   else
>>     pager = 0;
>>   if (pager && (! grub_strcmp (pager, "1")))
>>     grub_set_more (1);
>>
>> Can anyone confirm my suspictions that even the pager variable set to 1
>> there is NO stop on the screen when running a grub option that has the
>> cat command inside it with a big file?
> 
> Can you ellaborate?  From the code you pasted, I just see that when
> "interactive" is set to 0, this has the same effect as pager being set to
> the "0" string.

That's what I mean. I think that interactive for grub2 means being in 
the grub2 shell (not in a menu). If you are in a menu (non interactive) 
then there is no stop between pages.

But you know I am a bit lazy. I should at last try to do a grub.cfg and 
test it on my test floppy and see if I am right or not.

>> I am suspecting because in grub legacy there was the same stupid
>> behaviour which I fixed of course.
>>
>> I also do not like the way that pager is run. I mean, putting a getkey
>> inside the
>>
>> void
>> grub_putcode (grub_uint32_t code)
>>
>> function from: kern/term.c
>>
>> it seems to me a bit childish although I do not know so far a better
>> solution.
> 
> Please try to tear down that language!  "stupid" and "childish" are in general
> not very appropiate words for a development list.
Written down. Sorry, I'll try to use more formal synonims next time.
> 
> I suppose you're referring to:
> 
>           grub_printf ("--MORE--");
>           grub_setcolorstate (GRUB_TERM_COLOR_STANDARD);
> 
>           key = grub_getkey ();
> 
> What do you find wrong in this code?  AFAICS, the message is printed and then
> we use grub_getkey to block untill a key is pressed.  Sounds like normal
> pager-ish behaviour to me..

The code is ok. What I do not find ok is that the screen pause happens 
in a function which works it is to put a character on the screen.
I do not quite understand why a function that only has to print a 
character on the screen has also to deal with the screen by screen stop 
problem.

In my opinion this screen by screen stop problem should be solved in 
another part of the source code but so far I do not know where.

adrian15

Re: Pager does work from a menu?

[Robert Millan]

On Tue, Jun 12, 2007 at 04:16:59PM +0200, adrian15 wrote:
> >
> >Can you ellaborate?  From the code you pasted, I just see that when
> >"interactive" is set to 0, this has the same effect as pager being set to
> >the "0" string.
> 
> That's what I mean. I think that interactive for grub2 means being in 
> the grub2 shell (not in a menu). If you are in a menu (non interactive) 
> then there is no stop between pages.

Ah, yes.  Sounds like it.  Not sure if there was a reason for this, maybe
the ChangeLog shows something?

> But you know I am a bit lazy. I should at last try to do a grub.cfg and 
> test it on my test floppy and see if I am right or not.

Btw, do you know grub-emu?  It can probably help you with testing (rather
than grabbing to a floppy and reboot).

Ah, and there's also qemu (building a floppy image should be much easier now,
with grub-mkrescue).

> >
> >          grub_printf ("--MORE--");
> >          grub_setcolorstate (GRUB_TERM_COLOR_STANDARD);
> >
> >          key = grub_getkey ();
> >
> >What do you find wrong in this code?  AFAICS, the message is printed and 
> >then
> >we use grub_getkey to block untill a key is pressed.  Sounds like normal
> >pager-ish behaviour to me..
> 
> The code is ok. What I do not find ok is that the screen pause happens 
> in a function which works it is to put a character on the screen.
> I do not quite understand why a function that only has to print a 
> character on the screen has also to deal with the screen by screen stop 
> problem.
> 
> In my opinion this screen by screen stop problem should be solved in 
> another part of the source code but so far I do not know where.

You can move the code that handles screen stops somewhere else, but it's
still the code that prints something that has to trigger it, since screen
stops happen precisely when '\n' is printed.  What would basicaly change is
that instead of getkey() you call something else (e.g. pause()).

You can also move it to a lower layer (grub_cur_term->putchar), but then you
have to duplicate code (which is bad).

-- 
Robert Millan

My spam trap is honeypot@aybabtu.com.  Note: this address is only intended
for spam harvesters.  Writing to it will get you added to my black list.