Re: unicode (was Re: Minor error message change)

["John E. Davis" <davis>]

Pavel Roskin <proski@xxxxxxx> wrote:
>I mean, the right way to describe terminal capabilities is to read them
>from terminfo for the given $TERM.  If the terminal supports UTF-8, it's a
>property of the terminal.  This property is very important for S-Lang and
>similar libraries because it means that when certain bytes are sent to the
>terminal, the cursor will advance in a certain way.  The acsc capability
>may also be different if UTF-8 is supported.

I agree fully with you, however I know of no terminfo attribute that
says whether or not a terminal supports UTF-8.  Also I found the
following comment in the ncurses-5.3 source code dealing with line
drawing characters:

    /*
     * If we're running in a UTF-8 locale, will use the Unicode equivalents
     * rather than the terminfo information.  Actually the terminfo should
     * be the rule, but there are people who are offended by the notion that
     * a Unicode-capable terminal would have something resembling a mode.
     * So the smacs/rmacs may be disabled -- sometime.
     */
 

>TERM is for terminal capabilities.  Locale is for user preferences.
>Preferences can be different for different users.  I personally prefer
>POSIX locale, but I still want to be able to use terminals with UTF-8
>support.

Have you looked at

  http://www.cl.cam.ac.uk/~mgk25/unicode.html#activate

?  I do not know of anything more detailed than this when it comes to
practical standards concerning UTF-8 on a Unix system.  In particular,
this document describes how UTF-8 mode should be activated.

>My point is that we should be doing the right thing, cooperate and think
>ahead.  A lot of ugly standards appear because developers ignore those
>rules.  Cooperation means that we should approach xterm developers for
>make UTF-8 support more backward compatible.

Thanks,
--John