Some Definitions

Some Definitions

This section defines some of the terms used in this chapter.

Locale

Locale refers to a set of local customs that determine many aspects of software input and output formatting, including natural language, culture, character sets and encodings, and formatting and sorting rules. The locale of a program is the set of such parameters that are currently selected. For information on the method for selecting locales, see "Additional Reading on Internationalization" below.

Internationalization (i18n)

Internationalization is the process of making a program capable of running in multiple locales without recompiling. To put it another way, an internationalized program is one that can be easily localized without changing the program itself. (See "Localization (l10n)," below, for an explanation of the term "localization.")

Note: The word "internationalization" consists of an i followed by 18 letters followed by an n. It is thus often abbreviated "i18n" in informal writing. On similar principles, "localization" is often abbreviated "l10n." A program written for a specific locale may be difficult to run in a different environment. Rewriting such a program to operate in each desired environment would be tedious and costly.

Your goal as a developer should thus be to write locale-independent programs, programs that make no assumptions about languages, local customs, or coded character sets. Such internationalized applications can run in a user's native environment following native conventions with native messages, without recompiling or relinking. A single copy of an internationalized program can be used by a world of different users.

Localization (l10n)

Localization is the act of providing an internationalized application with the environment and data it needs to operate in a particular locale. For example, adding German system messages to IRIX is a part of localizing IRIX for the German locale.

Nationalized Software

Nationalized programs run in only one language and are governed by one set of customs; in other words, in a nationalized program the locale is built into the application. Even if the application doesn't use ASCII or English, as long as it is a single-language program it is nationalized, not internationalized. Most older UNIX programs can be thought of as being nationalized for the United States.

Consider two applications, hello and bonjour. The application hello always produces the output

Hello, world.

and bonjour always produces

Bonjour, tout le monde.

Neither hello nor bonjour are internationalized; they are both nationalized.

There are no special requirements for writing or porting nationalized applications, whether they are text or graphics programs. Terminal-based programs work on suitable terminals, including internationalized terminal emulators. "Suitable" means that the terminal supports any necessary fonts and understands the encoding of the application output. Graphics programs simply do as they have always done. Applications using existing interfaces to operate in non-English or non-ASCII environments should continue to compile and run under an internationalized operating system.

Multilingual Software

A multilingual program is one that uses several different locales at the same time. Examples are described in "Multilingual Support".