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Chapter 9

Internal Processing and File I/O

There are many text processing softwares, such as

grep

,

groff

,

head

,

sort

,

wc

,

uniq

,

nl

,

expand

, and so on. There are also many script languages which are often used for text processing,

such as

sed

,

awk

,

perl

,

python

,

ruby

, and so on. These softwares need to be internationalized.

From a user's point of view, a software can use any internal encodings if I/O is done correctly. It

is because a user cannot be aware of which kind of internal code is used in the software.

There are two candidate for internal encoding. One is wide character and the another is UCS 4.

You can also use Mule type encoding, where a pair of a number to express CCS and a number to

express a character consist a unit.

I recommend to use wide character, for reasons I alread explained in `LOCALE technology' on

page

53

, i.e., wide character can be encoding independent and can support various encodings in

the world including UTF 8, can supply a common united way for users to choose encodings, and

so on.

Here a few examples of handling of

wchar_t

are shown.

9.1 Stream I/O of Characters

The following program is a small example of stream I/O of wide characters.

#include 

#include 

#include 

main()

{

wint_t c;