How to use sqlplus with utf8 on windows command line

Question

I expected sqlplus to work interactively with the following settings:
- Lucida Console font for command window
- chcp 65001 (UTF8-Windows-Codepage)
- set NLS_LANG=.AL32UTF8
But it turned out that
1) sqlplus apparently does not use WIN32-API function ReadConsoleW and WriteConsoleW (these wide char functions must be used instead of ReadFile and WriteFile for Console I/O)
2) cmd silently ignores all .cmd and .bat files with codepage set to 65001.
I fear that such a problem regarding a minority of command line freaks has low priority for Oracle and for Microsoft, so I wrote two small filters in C.
rconsu8 passes keyboard input to stdout, using ReadConsoleW
wconsu8 passes stdin to console, using WriteConsoleW
both set the UTF8-codepage 65001 and restore the previous codepage at exit.
Anybody interested?
(Yes, I know that I could use sqldeveloper.)
Sample session:
C:\>set NLS_LANG=.AL32UTF8
C:\>rconsu8 | sqlplus scott/tiger@DBUTF8 | wconsu8
SQL> select '€' from dual;
'€'
€
SQL> select * from test_cyrillic;
NAME
Йозеф
Euro €

Answer 1

Console Output
works for characters covered by Lucida Console font if the first character in a line is ASCII (code < 128, e.g. blank)
CHCP 65001
sqlplus
SQL> select ' ', unistr('Josef \0419\043E\0437\0435\0444') from dual;
Josef Йозеф
SQL> select ' ',unistr('Euro \20AC') from dual;
Euro €
Sven, windows is able to render the output (as covered by Lucida Console), but there is a quirk in MSVCRTxx (C Runtime-Lib), function fwrite(). The first byte in a line is passed separately to an isolated single write() call, which causes conversion of an utf8 sequence to fail.
Console Input
For non-ascii characters (code >= 128), ReadConsoleW must be called, e.g. through a simple filter converting UTF-16 stdin to UTF-8 stdout.