4.1 Internationalized Applications with Unicode

The Unicode codeset enables developers to write applications that support multiple scripts simultaneously. The base language script and one or more additional scripts, depending on the Unicode locale, can be input, displayed, and printed. Distributed applications within network environments can also provide individual users access to different language environments simultaneously.

By itself, an application using Unicode is not fully internationalized. For example, if an application customizes data handling for Unicode directly, it needs to provide codeset converters as wrappers to support a codeset other than Unicode. This approach is direct Unicode localization--not internationalization. With direct localization, developers may localize an application that duplicates or conflicts with the localization provided by the operating system. In addition, an application may assume that all characters are represented in two-octet cells, which conflicts with UTF-8.

To properly internationalize an application, use the following guidelines:

• Avoid direct access with Unicode. (This is a task of the platform's internationalization framework.)

• Use the POSIX model for multibyte and wide-character interfaces. See Section 4.2, Unicode Application Interfaces.

• Only call APIs that the internationalization framework provides for language and cultural-specific operations. All POSIX, X11, Motif, and CDE interfaces are available to Unicode locales.

• Remain codeset independent.