Alternate characters at bottem right hand corner.

Leo de Wit leo at ehviea.ine.philips.nl
Thu Jun 28 17:12:40 AEST 1990


(Mail to T. Kramer failed; phigate!nluug.nl!MAILER-DAEMON says:
554 theo at wiggles... undomained host not known : wiggles)

In article <13250 at smoke.BRL.MIL> gwyn at smoke.BRL.MIL (Doug Gwyn) writes:
|In article <1344 at wiggles.UUCP> theo at wiggles.UUCP (T. Kramer) writes:
|>Has anybody out there got a solution?
|
|You're not supposed to try to place a character at the LRC, for obvious
|reasons.

I suppose by 'obvious reasons' you meant the scrolling of the display;
this depends on the type of terminal, and the mode it is in (automargin
on/off). For instance, on a vt220 you _can_ place a character at the
LRC. The following test program was run both with BSD curses and AT&T
curses (on a Pyramid):

#include <curses.h>

main()
{
	initscr();
        scrollok(stdscr,TRUE);
        clear();
        box(stdscr,'|','-');
        refresh();
	getch();
	endwin();
}

Results for a vt220: both versions use the LRC, the AT&T one uses the
enter insert mode (smir) sequence to accomplish this, it also ends each
line - except the last - with a carriage return (which is bogus IMHO,
since the terminfo entry has the 'am' capability).

Results for a vt100 (which doesn't have an insert character or enter
insert mode capability): the BSD version places a character at the LRC,
the AT&T version doesn't.  If you leave out the scrollok(), it makes no
difference for the AT&T version, the BSD version however doesn't use
any of the corners anymore (for the box()). Even if you create a
terminfo entry for a 'vt100 without automargin', AT&T curses refuses to
use the LRC.

|          However, on terminals that support character (or, yuck, line)
|insertion, you can achieve the same effect by building a last line with
|some earlier character left out, then insert the left-out character to
|shift the rest of the line over.

Unfortunately, the vt100 (one of the terminals this was asked for)
doesn't support character insertion.

    Leo.



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