AIX Version 4.3 Differences Guide

This presents a bit of a problem since is defined
in all four codesets, is only defined in
ISO8859-7 and UTF-8, and is defined only in
ISO8859-5 and UTF-8. Such a situation could be coded as follows with the
preprocessor directives:
upper /
/
#if defined(ISO88597) || defined(UTF8)
;/
#endif
#if defined(ISO88595) || defined(UTF8)
;
#endif
Using such techniques, it is possible to create a locale definition that tailors itself
to the code set being compiled against while not requiring you to define dummy
codepoints in the charmap. This technique also fulfills the requirement that all
locales for a given country be generated from the same locale source definition,
so that consistency is achieved within a given language/territory combination.
To support Unicode symbol names in charmaps and localedef source files, the
localedef command has been modified to accept symbol names of at least 85
characters instead of the current limit of 32. Currently, the longest symbol name
from the Unicode standard is 83 characters long, not including the required < and
> delimiters. This is a simple modification to symtab.h and has been done without
any impact on performance, as the symbol names are only used during locale
compilation, not at run time.
10.3.3.2 Locale Methods
The current set of locale methods, as provided in libc, was implemented based on
the locales supported in AIX Version 3.2. Since that time, many new locales have
been added to the system, mostly with corresponding locale-specific methods. It
is a goal of this design to minimize the number of locale-specific method objects
required and also to provide a framework under which future AIX locales can be
easily added.
Locale-specific methods that are no longer used will remain in the libc.a library in
order to insure binary compatibility. The following is the set of locale-specific
methods that are provided with AIX Version 4.3. These locale methods have been
placed into libi18n.a, instead of libc.a, to minimize incompatibilities with previous
releases.
mblen()
Determine the length (in bytes) of a multi-byte character. This is the
most difficult method to generalize. The following locale-specific
variants are supported:
• __mblen_sb() - For single-byte code sets, always returns 1.
• __mblen_utf() - multi-byte determination rules for UTF-8-based
locales.
National Language Support 245