[TUHS] Anyone know what a LANTERN is?
Alan D. Salewski
salewski at att.net
Sat Jul 29 17:06:33 AEST 2017
On 2017-07-28 13:46:40, Paul Ruizendaal spake thus:
>
> > Message: 1
> > Date: Thu, 27 Jul 2017 11:58:38 -0400
> > From: Random832 <random832 at fastmail.com>
> > To: tuhs at minnie.tuhs.org
> > Subject: [TUHS] Anyone know what a LANTERN is?
> > Message-ID:
> > <1501171118.69633.1054588920.11864815 at webmail.messagingengine.com>
> > Content-Type: text/plain; charset="utf-8"
> >
> > There is a character in the terminfo/curses alternate character set,
> > ACS_LANTERN, which is mapped to "i" in the VT100 alternate grapical
> > character set. This character is, in fact, on a real VT100/VT220 (and
> > therefore in most modern terminal emulators that support the full ACS),
> > "VT" (in 'control character picture' format, along with HT FF CR LF NL).
> > The ASCII mapping uses "#", and some CP437/etc mappings map it to the
> > double box drawing intersection character.
> >
> > Was there ever a real 'lantern' character? The manpage mentions "some
> > characters from the AT&T 4410v1 added". What did it look like?
>
> There's two references in the termcap manpages:
> http://invisible-island.net/ncurses/man/terminfo.5.html
> and
> http://invisible-island.net/ncurses/man/curs_add_wch.3x.html
>
> The second link mentions that the AT&T 4410 terminal added this glyph in the location of the VT100 VT glyph. Apparently what it looked like is lost, unless someone finds a detailed 4410 manual (or has a working one in the attic).
>
The wecho_wchar(3ncurses) page[0] on my Debian box happens to mention
the following[1] in a discussion about incorporating Unicode support:
<quote>
· The lantern is a special case. It originated with the AT&T 4410
terminal in the early 1980s. There is no accessible documentation
depicting the lantern symbol on the AT&T terminal.
Lacking documentation, most readers assume that a storm lantern was
intended. But there are several possibilities, all with problems.
Unicode 6.0 (2010) does provide two lantern symbols: U+1F383 and
U+1F3EE. Those were not available in 2002, and are irrelevant
since they lie outside the BMP and as a result are not generally
available in terminals. They are not storm lanterns, in any case.
Most storm lanterns have a tapering glass chimney (to guard against
tipping); some have a wire grid protecting the chimney.
For the tapering appearance, ☃ U+2603 was adequate. In use on a
terminal, no one can tell what the image represents. Unicode calls
it a snowman.
Others have suggested these alternatives: § U+00A7 (section mark),
Θ U+0398 (theta), Φ U+03A6 (phi), δ U+03B4 (delta), ⌧ U+2327 (x in
a rectangle), ╬ U+256C (forms double vertical and horizontal), and
☒ U+2612 (ballot box with x).
</quote>
[0] From a version 6.0+20170715-2 of the 'ncurses-doc' package:
$ man -aw wecho_wchar
/usr/share/man/man3/add_wch.3ncurses.gz
$ dpkg -S $(man -aw wecho_wchar)
ncurses-doc: /usr/share/man/man3/add_wch.3ncurses.gz
$ dpkg -l ncurses-doc | grep '^i'
ii ncurses-doc 6.0+20170715-2 all developer's guide and documentation for ncurses
[1] Which, AFAICT is a recent addition to the page, documented by the
below NEWS file entry:
<quote src="http://invisible-island.net/ncurses/NEWS.html#index-t20170506">
20170506
...
+ improve discussion of line-drawing characters in curs_add_wch.3x
(prompted by discussion with Lorinczy Zsigmond).
...
</quote>
More information about the TUHS
mailing list