hztty - make a tty session understand different encodings

hztty [ -h ] [ -I input-stream ] [ -O output-stream ] [command line]

hztty translates Chinese codes on your terminal from some foreign encoding or representation standard to the native encoding understandable by your terminal. A native encoding is the standard used by your terminal session, for example ``GB'' on ``cxterm'', ``Big5'' on ``cxterm -BIG5'' or ET Dos. A foreign encoding is the one used by application running on the terminal, for example, the ``zW/HZ'' representation, the standard ``Unicode'', the ASCII-compatible ``UTF8'', the mail-safe ``UTF7'', etc. hztty also translates Chinese codes you input on your terminal from the native encoding to the foreign encoding used by the application.

hztty was initially designed to read/post articles in the newsgroup ``alt.chinese.text'', in which the ``zW/HZ'' scheme is used to represent Chinese characters. Now it can do much more than that.

hztty ends when the forked shell exits.

The Chinese code conversion in hztty is organized using the stream mechanism. A stream consists of one or more conversion modules. Each of these modules implements a different kind of code conversion. In a stream the conversion modules form a pipeline that feeds one module's output to the next module's input. There is an input stream (from terminal input to the application) and an output stream (from the application to the terminal screen) in hztty. This version of hztty implements the following conversion modules.

hz2gb

It converts zW/HZ to GB, usually used in output stream.

gb2hz

It converts GB to zW/HZ, usually used in input stream. Note that you have to type in the escape sequences yourself and make the text conforms to HZ specification. Hztty enforces no encoding policy.

gb2big

It converts GB to Big5.

big2gb

It converts Big5 to GB.

uni-utf

It converts 16bit Unicode to 8-bit UTF format.

utf-uni

It converts 8-bit UTF format to 16bit Unicode.

uni-utf7

It converts 16bit Unicode to 7-bit mail-safe UTF format (RFC1642).

utf7-uni

It converts the 7-bit mail-safe UTF format to 16bit Unicode.

gb2uni

It converts GB to 16bit Unicode.

uni2gb

It converts 16bit Unicode to GB.

big2uni

It converts Big5 to 16bit Unicode.

uni2big

It converts 16bit Unicode to Big5.

toascii

toupper tolower They converts ASCII as those of ctype(3).

dummy

It does no conversion, bindly copying from the previous module to the next module.

log(filename) It does no conversion but saves a copy of every characters that passes through this module in a log file named filename. Be aware that the log file grows very fast since everything you type and all program output are saved.

-h

prints the help message and lists all the module implemented.

-I

specifies the input stream. If there are more than one modules in the stream, the module names are separated by `:'. The default input stream is ``gb2hz''.

-O

specifies the output stream. If there are more than one modules in the stream, the module names are seperated by `:'. The default output stream is ``hz2gb''. If command line is not given, the user selected shell (from the environment variable SHELL) is invoked in the hztty session. Otherwise, the command line is invoked instead of the shell.

Examples of conversion module combination in IO streams:

hztty

It implies the default input/output streams of -O hz2gb -I gb2hz. It is useful in reading and writing HZ style Chinese codes (as in the newsgroup ``alt.chinese.text'').

hztty -O hz2gb:gb2big -I big2gb:gb2hz

converts between HZ and Big5. In the output stream, HZ output are converted to GB first, then to Big5. In the input stream, Big5 input are converted to GB first, then to HZ. Useful in reading ``alt.chinese.text'' in a Big5 cxterm or other terminal emulator (e.g., kermit over IBM-PC running ET DOS).

hztty -O utf-uni:uni2gb -I gb2uni:uni-utf

converts UTF output into GB in the output stream and GB into UTF in the input stream.

HZ - A Data Format for Exchanging Files of

Arbitrarily Mixed Chinese and ASCII characters

More on Unicode in ftp://unicode.org/pub/

Yongguang Zhang (ygz@cs.purdue.edu)

Copyright @ 1992, 1995 by Yongguang Zhang

Permission to use, copy, modify, and redistribute is hereby granted. The author disclaims all warranties with regarding to this software.

Norm Matloff, University of California at Davis, (matloff@cs.ucdavis.edu), contributes his code for reading zW/HZ in a Big5 cxterm on the fly.

The Big5/GB conversion tables are generated from HC 1.2u, by Feng Feng Lee of Stanford University and Ricky Yeung of Washington University (now with Sun Microsystems).

The Unicode conversion tables are generated from Ross Paterson's utf7 package. (<rap@doc.ic.ac.uk>)

Shangjie Jin of Edinburgh University, UK, (sjin@castle.edinburgh.ac.uk), ported hztty to sequent boxes.

Cannot dynamically add (delete) a conversion module to (from) the streams.