Re: [PATCH] Add support for ANSI.SYS SCP/RCP escape codes

[James Clarke]

Currently the new "apt" command-line tool relies on them (when it installs 
packages, it keeps a progress bar at the bottom, but shows a log above), 
although they've recently patched it to use the more widely-available ESC 7/8 
(though the patch is not yet in sid).
I chose SCP/RCP, because ANSI.SYS called them Save/Restore Cursor Position, and 
everywhere seems to refer to them by that acronym (they're even listed on 
Wikipedia in the table of codes, despite not being in ECMA-48, nor being 
implemented by the VT100).

James

> On 12 Sep 2015, at 10:15, Samuel Thibault <samuel.thibault@gnu.org> wrote:
> 
> Hello,
> 
> James Clarke, le Sat 12 Sep 2015 00:42:05 +0100, a écrit :
>> This adds support for CSI s and u, which are equivalent to ESC 7 and 8,
>> saving/restoring the cursor position.
> 
> Just curious: in which case did you see it a problem, or is it just for
> completeness? (which can always become convenient anyway)
> 
>> +    case 's':        /* ANSI.SYS: Save cursor and attributes.  */
>> +      /* Save cursor position: <scp>.  */
> 
> Why scp?  AIUI from terminfo(5), scp is the capname for set_color_pair,
> the tcap code for save cursor position is sc.
> 
>> +      display->cursor.saved_x = user->cursor.col;
>> +      display->cursor.saved_y = user->cursor.row;
>> +      break;
>> +    case 'u':        /* ANSI.SYS: Restore cursor and attributes.  */
>> +      /* Restore cursor position: <rcp>.  */
>> +      user->cursor.col = display->cursor.saved_x;
>> +      user->cursor.row = display->cursor.saved_y;
>> +      /* In case the screen was larger before:  */
>> +      limit_cursor (display);
>> +      break;
>>     case 'l':
>>       /* Reset mode.  */
>>       for (i = 0; i < parse->nparams; i++)
>> -- 
>> 2.5.1
>> 
>>