[EMAIL PROTECTED] (Kai Henningsen) wrote:
> So I propose an interface that has approximately the following features:
>
Very much like ANSI X3.64, the basis of VT220 and above and many others.
This standard is very well thought out already, particularly as to structural
issues. Even though the standard was revoked, copies can still be had from
ANSI. Anybody who wants to design a new terminal standard should first read
it. And also be thoroughly familiar with ISO standards including 4873, 2022,
and 6429.
> * Similarly, there is a way to ask the terminal for enough internal state
> as to be able to restore the state (this is important, for example, when
> calling out to a different program that needs different option states but
> wishes to restore the display before returning). One of the things one can
> query should be the current display contents.
>
Careful. Those who don't remember history are doomed to repeat it.
There is no bigger security risk than being able to command a terminal to
send its screen contents, or portions of it. 30 years ago it was called
the "Berkeley bug".
We should also be mindful of a certain inherent drawback of UTF-8, which I
mentioned on the Unicode list, but nobody there is much concerned with
terminals. We have added UTF-8 capability to some of our Kermit terminal
emulators, and it works nicely as long as we follow the rule: "decode the
incoming UTF-8 data stream BEFORE feeding it to the terminal emulator".
Sending UTF-8, however, is another matter entirely when the host is (a)
standards compliant but (b) unaware of UTF-8. In this case, if we type
characters in certain Unicode blocks (such as Cyrillic uppercase letters A
through PE), the UTF-8 includes C1 control characters, which a
standards-compliant terminal driver will treat as such or (more likely)
treat as their C0 companions.
But for this, you could use a UTF-8 terminal emulator to read and write
text in many languages across a Telnet connection to a host that was totally
unaware of UTF-8, just as you can today with (say) Latin-1.
- Frank
-
Linux-UTF8: i18n of Linux on all levels
Archive: http://mail.nl.linux.org/lists/
