Chapter 4. Coded Character Sets And Encodings in the World

31

Now Windows comes to support Unicode and the font at

u+005c

for Japanese version of Win 

dows is yen currency mark. As you know, backslash (yen currency mark in Japan) is vitally im 

portant for Windows, because it is used to separate directory names. Fortunately, EUC JP, which

is widely used for UNIX in Japan, includes ASCII, not Japanese version of ISO 646. So this is not

problem because it is clear

0x5c

is backslash.

Thus all local codesets should not use character sets incompatible to ASCII, such as ISO 646 *.

Problems and Solutions for Unicode and User/Vendor Defined Characters (

http://www.opengroup.

or.jp/jvc/cde/ucs conv e.html

) discusses on this problem.

4.5 Other Character Sets and Encodings

Besides ISO 2022 compliant coded character sets and encodings described in `ISO 2022 compliant

Character Sets' on page

22

and `ISO 2022 compliant Encodings' on page

24

, there are many popu 

lar encodings which cannot be classified into an international standard (i.e., not ISO 2022 compliant

nor Unicode). Internationalized softwares should support these encodings (again, you don't need

to be aware of encodings if you use LOCALE and

wchar_t

technology). Some organizations

are developing systems which go father than limitations of the current international standards,

though these systems may be not diffused very much so far.

4.5.1 Big5

Big5 is a de facto standard encoding for Taiwan (1984) and is upward compatible with ASCII. It

is also a CCS.

In Big5,

0x21

0x7e

means ASCII characters.

0xa1

0xfe

makes a pair with the following byte

(

0x40

0x7e

and

0xa1

0xfe

) and means an ideogram and so on (13461 characters).

Though Taiwan has ISO 2022 compliant new standard CNS 11643, Big5 seems to be more popular

than CNS 11643. (CNS 11643 is a CCS and there are a few ISO 2022 derived encodings which

include CNS 11643.)

4.5.2 UHC

UHC is an encoding which is an upward compatible with EUC KR. Two byte characters (the first

byte:

0x81

0xfe

; the second byte:

0x41

0x5a

,

0x61

0x7a

, and

0x81

0xfe

) include KSX

1001 and other Hangul so that UHC can express all 11172 Hangul.