Chapter 5. Characters in Each Country

40

and EUC JP, respectively. Note that difference between JIS X 0201 Roman and ASCII is ignored.

Though

nkf

can guess the encoding of the input file, you can specify the encoding by command

option. This is because there are no algorithm to completely distinguish EUC JP and SHIFT JIS,

though

nkf

usually guesses correctly.

tcs

can also convert these encodings, though without

guessing input encoding. Conversion between these encodings can be done with a simple algo 

rithm since all of them are based on the same character sets. You need a table for code conversion

between these encodings and Unicode.

5.1.4 How These Encodings Are Used   Information for Programmers

Since EUC JP is widely used for UNIX, EUC JP should be supported. Exceptions are shown be 

low. Of course direct implementation of knowledge on EUC JP is not encouraged. If you can

implement without the knowledge by use of

wchar_t

and so on, you should do so.

  the body of mail and news messages must be written in ISO 2022 JP.

  De facto standard of ICQ is SHIFT JIS.

  WWW browser must recognize all encodings.

  Softwares which communicate with Windows/Macintosh should use SHIFT JIS.

  SHIFT JIS is widely used for BBS. (BBS is a service like Compuserve).

  File names for Joliet format CD ROM used for Windows is written in Unicode.

5.1.5 Columns

In consoles which are able to display Japanese characters (kon, jfbterm, kterm, krxvt, and so on),

characters in JIS X 0201 (Roman and Kana) occupy 1 column and characters in JIS X 0208, JIS X

0212, and JIS X 0213 occupy 2 columns.

5.1.6 Writing Direction and Combined Characters

Japanese language can be written in vertical direction. A line goes downward and the row of lies

goes from right to left. This direction is the traditional style. For example, most Japanese books,

magazines and newspapers except for in the field of natural science (or ones containing many

Latin words or equations) are written in vertical direction. Thus a word processor is strongly rec 

ommended to support this direction. DTP systems which don't support this direction are almost

useless.