Screen Editing

[Thomas Dickey]

Re: Screen Editing

Tak-Shing Chan <t.chan@gold.ac .ukwrote:

On Thu, 17 Aug 2006, Thomas Dickey wrote:

>Mark McIntyre <markmcintyre@s pamcop.netwrote :

>>On Thu, 17 Aug 2006 22:40:44 +0100, in comp.lang.c , Tak-Shing Chan
>><t.chan@gold. ac.ukwrote:

>>

>>(stuff to some guy called Dickey).

>>
>hmm - this seems to be your usual level, so I won't follow your lead.
>>

>>Chan, given that my kill filters automatically picked this guy up, I
>>suspect "Dickey" is a sock puppet for an existing troll. I suggest you
>>killfile him.

>>
>not at all.
>Unlike present company, I happen to know what I'm talking about.

Really? Do you know anything about these 120 terminals?

Sure. And I know how to use google too. Since you don't, I'll help:

xterm supports ANSI color, VT220 emulation and UTF-8
There's an faq at

http://invisible-island.net/xterm/xterm.faq.html

ftp://invisible-island.net/xterm/

The current version of ncurses is 5.5 (20051010)
There's an faq at

http://invisible-island.net/ncurses/ncurses.faq.html

According to my termcap (yes, appealing to authority again), they
all respond to form feeds by clearing the screen:

Let's stick to "most" and "modern". Do you understand the terms?
I'm assuming you don't, given the list you presented -
even ignoring the duplicates.
(and no, I won't waste time here by giving a chronology ;-)

most+modern would imply something like "in widespread use during the past
ten years". There - add that to your glossary.

--
Thomas E. Dickey

http://invisible-island.net

ftp://invisible-island.net

[Ben Pfaff]

Re: Screen Editing

Keith Thompson <kst-u@mib.orgwrites :

"Ancient_Hacker " <grg2@comcast.n etwrites:

>The most portable way is dorky, but works most every place I can think
>of:
>>
>>
>for( i=1; i <= 66 + 24 /* for those TALL full page displays,plus
>lagniappe */; i++ )
> puts( "\n" );

>
There's no reason to assume that the terminal window is no taller than
66 rows. I'm typing this in a 65-row window, and I could easily
expand it.

(The above actually works with displays up to 180 rows high.)

For some reason, no one liked this suggestion of mine when I
brought it during the last discussion of this issue:

for (;;)
putchar('\n');

It should be effective just about everywhere, even on very tall
terminals or those with a circular scrollback buffer. It will
even get the attention of those using printing terminals.
--
int main(void){char p[]="ABCDEFGHIJKLM NOPQRSTUVWXYZab cdefghijklmnopq rstuvwxyz.\
\n",*q="kl BIcNBFr.NKEzjwC IxNJC";int i=sizeof p/2;char *strchr();int putchar(\
);while(*q){i+= strchr(p,*q++)-p;if(i>=(int)si zeof p)i-=sizeof p-1;putchar(p[i]\
);}return 0;}

[Tak-Shing Chan]

Re: Screen Editing

On Thu, 17 Aug 2006, Thomas Dickey wrote:

Tak-Shing Chan <t.chan@gold.ac .ukwrote:

>On Thu, 17 Aug 2006, Thomas Dickey wrote:

>

>>Mark McIntyre <markmcintyre@s pamcop.netwrote :
>>>On Thu, 17 Aug 2006 22:40:44 +0100, in comp.lang.c , Tak-Shing Chan
>>><t.chan@gold .ac.ukwrote:
>>>
>>>(stuff to some guy called Dickey).
>>>
>>hmm - this seems to be your usual level, so I won't follow your lead.
>>>
>>>Chan, given that my kill filters automatically picked this guy up, I
>>>suspect "Dickey" is a sock puppet for an existing troll. I suggest you
>>>killfile him.
>>>
>>not at all.
>>Unlike present company, I happen to know what I'm talking about.

>

> Really? Do you know anything about these 120 terminals?

>
Sure. And I know how to use google too. Since you don't, I'll help:
>
xterm supports ANSI color, VT220 emulation and UTF-8
There's an faq at

http://invisible-island.net/xterm/xterm.faq.html

ftp://invisible-island.net/xterm/
>
The current version of ncurses is 5.5 (20051010)
There's an faq at
http://invisible-island.net/ncurses/ncurses.faq.html

Irrelevant.

>According to my termcap (yes, appealing to authority again), they
>all respond to form feeds by clearing the screen:

>
Let's stick to "most" and "modern". Do you understand the terms?
I'm assuming you don't, given the list you presented -
even ignoring the duplicates.
(and no, I won't waste time here by giving a chronology ;-)
>
most+modern would imply something like "in widespread use during the past
ten years". There - add that to your glossary.

Are you saying that Sun SPARC machines are not ``in
widespread use during the past ten years''? That is news to me.

By the way, I believe that ``modern'' on comp.lang.c means
post-1989 (when ANSI C is born).

Tak-Shing

[Thomas Dickey]

Re: Screen Editing

Tak-Shing Chan <t.chan@gold.ac .ukwrote:

Are you saying that Sun SPARC machines are not ``in
widespread use during the past ten years''? That is news to me.

You cited several duplicates. "Widespread " is debatable in this case,
since (aside from the rarely-used console, Sun hasn't supported a terminal
emulator for this for more than ten years - it's been that long that the
openwin programs have been regarded as unsupported/legacy/doomed).

For the others - spend a few moments to see how long it's been since the
actual terminals were sold as new.

By the way, I believe that ``modern'' on comp.lang.c means
post-1989 (when ANSI C is born).

no - the topic changed from ANSI C to terminal emulators, and the modern
era for that was the related curses work in X/Open. 1996.

--
Thomas E. Dickey

http://invisible-island.net

ftp://invisible-island.net

[Tak-Shing Chan]

Re: Screen Editing

On Thu, 17 Aug 2006, Thomas Dickey wrote:

Tak-Shing Chan <t.chan@gold.ac .ukwrote:
>

> Are you saying that Sun SPARC machines are not ``in
>widespread use during the past ten years''? That is news to me.

>
You cited several duplicates. "Widespread " is debatable in this case,
since (aside from the rarely-used console, Sun hasn't supported a terminal
emulator for this for more than ten years - it's been that long that the
openwin programs have been regarded as unsupported/legacy/doomed).
>
For the others - spend a few moments to see how long it's been since the
actual terminals were sold as new.
>

> By the way, I believe that ``modern'' on comp.lang.c means
>post-1989 (when ANSI C is born).

>
no - the topic changed from ANSI C to terminal emulators, and the modern
era for that was the related curses work in X/Open. 1996.

That is only true if you are using UNIX. Many modern systems
do not use curses.

Tak-Shing

[Thomas Dickey]

Re: Screen Editing

Tak-Shing Chan <t.chan@gold.ac .ukwrote:

On Thu, 17 Aug 2006, Thomas Dickey wrote:

>no - the topic changed from ANSI C to terminal emulators, and the modern
>era for that was the related curses work in X/Open. 1996.

That is only true if you are using UNIX. Many modern systems
do not use curses.

Those that don't, either use vt100-compatible terminals (OpenVMS), or do
not make use of terminals (barring the miniscule fraction running Plan 9 ;-)

hmm - a few readers of this group could tell if 9term clears the screen
on a form-feed (it doesn't appear so to me, from reading its code).

--
Thomas E. Dickey

http://invisible-island.net

ftp://invisible-island.net

[Tak-Shing Chan]

Re: Screen Editing

On Thu, 17 Aug 2006, Thomas Dickey wrote:

xterm supports ANSI color, VT220 emulation and UTF-8
There's an faq at

http://invisible-island.net/xterm/xterm.faq.html

ftp://invisible-island.net/xterm/
>
The current version of ncurses is 5.5 (20051010)
There's an faq at
http://invisible-island.net/ncurses/ncurses.faq.html

No wonder you are so keen on xterm and ncurses---I just
noticed that you are the current maintainer of both!

Tak-Shing

[Tak-Shing Chan]

Re: Screen Editing

On Fri, 18 Aug 2006, Thomas Dickey wrote:

Tak-Shing Chan <t.chan@gold.ac .ukwrote:

>On Thu, 17 Aug 2006, Thomas Dickey wrote:

>

>>no - the topic changed from ANSI C to terminal emulators, and the modern
>>era for that was the related curses work in X/Open. 1996.

>

> That is only true if you are using UNIX. Many modern systems
>do not use curses.

>
Those that don't, either use vt100-compatible terminals (OpenVMS), or do
not make use of terminals (barring the miniscule fraction running Plan 9 ;-)

There are embedded Linux systems without curses.

Tak-Shing

[J. J. Farrell]

Re: Screen Editing


Tak-Shing Chan wrote:

On Thu, 17 Aug 2006, Keith Thompson wrote:
>

Andrew Smallshaw <andrews@sdf.lo nestar.orgwrite s:
[...]

Most terminals, particularly modern ones, will clear the screen if
you simply send them a formfeed. It's not guaranteed, but it's a
similar kind of assumption to backspace will move the cursor left
which seems pretty much standard these days.

I haven't found that to be the case for any of the terminal emulators
I use. I've just tried xterm, dtterm, gnome-terminal, a Windows
command window, the GNU "screen" program, and rxvt; none of them clear
the screen in response to a formfeed character.

>
I have just posted a long list elsethread.

You posted a long list which has no obvious relevance to the point in
question. The list is a long way from "most terminals" and few of the
ones listed count as modern (one was recently sold as a rare antique
computer, many are archaic museum pieces).

[Thomas Dickey]

Re: Screen Editing

Tak-Shing Chan <t.chan@gold.ac .ukwrote:

No wonder you are so keen on xterm and ncurses---I just
noticed that you are the current maintainer of both!

That's been the case for more than ten years.

--
Thomas E. Dickey

http://invisible-island.net

ftp://invisible-island.net

[Thomas Dickey]

Re: Screen Editing

Tak-Shing Chan <t.chan@gold.ac .ukwrote:

On Fri, 18 Aug 2006, Thomas Dickey wrote:

>Those that don't, either use vt100-compatible terminals (OpenVMS), or do
>not make use of terminals (barring the miniscule fraction running Plan 9 ;-)

There are embedded Linux systems without curses.

Which are the ones running a widely-used non-vt100-compatible terminal?

--
Thomas E. Dickey

http://invisible-island.net

ftp://invisible-island.net

[Tak-Shing Chan]

Re: Screen Editing

On Fri, 18 Aug 2006, Thomas Dickey wrote:

Tak-Shing Chan <t.chan@gold.ac .ukwrote:

>On Fri, 18 Aug 2006, Thomas Dickey wrote:

>

>>Those that don't, either use vt100-compatible terminals (OpenVMS), or do
>>not make use of terminals (barring the miniscule fraction running Plan 9 ;-)

>

> There are embedded Linux systems without curses.

>
Which are the ones running a widely-used non-vt100-compatible terminal?

Widely-used? I don't know. But there exists systems where
you can access the console thru the serial port---I've seen a
few of those.

Tak-Shing

[Thomas Dickey]

Re: Screen Editing

Tak-Shing Chan <t.chan@gold.ac .ukwrote:

On Fri, 18 Aug 2006, Thomas Dickey wrote:

>Tak-Shing Chan <t.chan@gold.ac .ukwrote:

>>On Fri, 18 Aug 2006, Thomas Dickey wrote:

>>

>>>Those that don't, either use vt100-compatible terminals (OpenVMS), or do
>>>not make use of terminals (barring the miniscule fraction running Plan 9 ;-)

>>

>> There are embedded Linux systems without curses.

>>
>Which are the ones running a widely-used non-vt100-compatible terminal?

Widely-used? I don't know. But there exists systems where
you can access the console thru the serial port---I've seen a
few of those.

A serial port is a data connection (a wire)
It doesn't present data (a terminal).

Again, unless it's widely used, it doesn't add to the "most" category.

--
Thomas E. Dickey

http://invisible-island.net

ftp://invisible-island.net

[Tak-Shing Chan]

Re: Screen Editing

On Fri, 17 Aug 2006, J. J. Farrell wrote:

>
Tak-Shing Chan wrote:

>On Thu, 17 Aug 2006, Keith Thompson wrote:
>>

>>Andrew Smallshaw <andrews@sdf.lo nestar.orgwrite s:
>>[...]
>>>Most terminals, particularly modern ones, will clear the screen if
>>>you simply send them a formfeed. It's not guaranteed, but it's a
>>>similar kind of assumption to backspace will move the cursor left
>>>which seems pretty much standard these days.
>>>
>>I haven't found that to be the case for any of the terminal emulators
>>I use. I've just tried xterm, dtterm, gnome-terminal, a Windows
>>command window, the GNU "screen" program, and rxvt; none of them clear
>>the screen in response to a formfeed character.

>>
> I have just posted a long list elsethread.

>
You posted a long list which has no obvious relevance to the point in
question. The list is a long way from "most terminals" and few of the
ones listed count as modern (one was recently sold as a rare antique
computer, many are archaic museum pieces).

OK. Let me trim it down to just one item: the Sun console.
It is certainly still in use today, and it does clear the screen
with '\f'. But you are absolutely right, this has little
relevance to ``most terminals''. Perhaps I should s/most/some/g.

Tak-Shing

[Tak-Shing Chan]

Re: Screen Editing

On Fri, 18 Aug 2006, Thomas Dickey wrote:

Tak-Shing Chan <t.chan@gold.ac .ukwrote:

>On Fri, 18 Aug 2006, Thomas Dickey wrote:

>

>>Which are the ones running a widely-used non-vt100-compatible terminal?

>

> Widely-used? I don't know. But there exists systems where
>you can access the console thru the serial port---I've seen a
>few of those.

>
A serial port is a data connection (a wire)
It doesn't present data (a terminal).

The serial driver doesn't, but the console driver does.

Again, unless it's widely used, it doesn't add to the "most" category.

Fair enough.

Tak-Shing