vnelvis(1V)

NAME
vnelvis - elvis with Vietnamese capability

SYNTAX
vnelvis [regular_elvis_options]

DESCRIPTION

Vnelvis is an adaptation of Steve Kirkendall's public domain vi clone, elvis command. It is preferable to vi because most current vi implementations allow only 7-bit text editing which is inappropriate for the 8-bit Vietnamese character set. This manual page describes only those features specific to vnelvis ; please consult the documentation for elvis and vi for the rest of the story. If you are already familiar with vi , no special training is necessary.

Vnelvis allows user to edit Vietnamese text with the keyboard input style according the 7-bit VIQR standard, which is based on the prevalent Vietnamese networking convention of placing Vietnamese diacritical marks after the vowel, for example: "Vie^.t Nam". The result is true 8-bit Vietnamese text (according to the VISCII standard).

In order to use vnelvis, you must have a terminal capable of displaying Vietnamese, e.g., vnterm 1V or vietterm 1V

There is one user-definable setting with vnelvis: vnkeys . It is handled as regular vi variables and can be set with your .exrc or your EXINIT environment variable, e.g.,:
    set vnkeys
    set novnkeys
    or in abbreviated form
    set vnk
    set novnk
or in ed-command mode:
    :set vnkeys
The variable vnkeys specifies whether Vietnamese input processing is to be performed; when it is off, vnelvis behaves as a regular elvis or vi , except that 8-bit data is supported. Note that keyboard filtering is only done in input mode and not in vi-command mode, which is most convenient for the user.

The default settings is with vnkeys off. The reason for this is because users will typically start vnelvis from within a vnterm or vietterm window, which is already doing its Vietnamese keyboard filtering.

STATUS DISPLAY
When the vi-variable showmode is set, vnelvis reports the language mode at the bottom of the screen; it can be one of Vietnamese, English, or Literal. Switching aong the three is accomplished with the keyboard sequence "\V", "\M", and "\L", for Vietnamese, English, and Literal modes, respectively.

USAGE NOTES

o   When using vnelvis in conjunction with vnterm 1V , remember to turn off keyboard processing by either vnelvis or vnterm , otherwise the results of your keypresses going through two Vietnamese filters may be somewhat confusing.

o   vnelvis is currently the only alternative that would correctly handle the six Vietnamese characters "A(? A(~ A^~ Y? Y~ Y." as they are coded in the C0 control area. For best results when using vnelvis and vnterm , it is recommended that you turn on vnelvis 's keyboard filter (:set vnkeys) and turn off vnterm 's keyboard filtering. This will ensure that Vietnamese characters are generated only in input mode when you typically really want them.

o   On the other hand, if you prefer leaving vnterm 's or vietterm 's keyboard filtering on and turn off vnelvis 's keyboard filter, you may find commands such as "dd" (delete line) awkward, because the "dd" is converted first to the Vietnamese character "d-bar" before it is sent to vnelvis. Therefore you must either type "d\d" to prevent the composition action, or use the "qq" sequence which has been implemented in vnelvis as a substitute for "dd".

AUTHOR
Adapted from Steve Kirkendall's elvis.1.4 by Cuong T. Nguyen, the TriChlor Group, TriChlor@haydn.Stanford.EDU

SEE ALSO
viqr(3V), vntype(3V), vi(1), elvis(1l)

STANDARDS
Viet-Std Standardization Specification (Viet-Std@Haydn.Stanford.EDU)

RFC 1456 Vietnamese Standardization Working Group, "Conventions for Encoding the Vietnamese Language
VISCII: VIetnamese Standard Code for Information Interchange
VIQR: VIetnamese Quoted-Readable Specification Revision 1.1",
May 1993.