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AIX Version 4.3 AIXwindows Programming Guide

AIXwindows National Language Support (NLS)


Internationalization is a method of application development that enables an application to be used in a variety of locales. The concept of a locale is used to encompass the characteristics and requirements of a given language. An internationalized application requires that any language-dependent or custom-dependent information be stored external to the application program. A locale can be characterized by several components. For example, character sets, sort order, text direction, and formats for data (such as date and currency) are used to describe the unique characteristics of a locale. For each different locale, information (such as menu items, help information, and user prompts) is defined and stored separately. The information is localized, which means that it has been tailored for a specific language and country.

An application designed to run in different locales examines certain resources and environment variables in order to determine which language to use when run. An application establishes file search paths for resource files and other language-dependent information. There is a wide variety of information that can be localized. Localized information is stored in files that reside in different directories. AIXwindows uses an underlying Xt Intrinsics mechanism (XtResolvePathname) to select and locate the appropriate files, depending on the locale.

An internationalized application can set its locale at run time, typically using an internal procedure called a language procedure. The language procedure processes data in your user environment and sets the application's locale. This feature enables you to modify your user environment and rerun an application in a different locale. An application can use a default language procedure or supply its own procedure. As a result, two applications can process the same user environment data with different results. Refer to the user documentation for the application you intend to use for detailed instructions.

An input method is the underlying mechanism that takes keyboard input and displays the locale's corresponding characters on the screen. An input method interprets the user's keystrokes based on the conventions supplied by the input method. The input method used by an application based on an alphabetic language is generally not visible. However, ideographic languages such as Chinese or Japanese may use an input method that composes keystrokes in a separate window called a pre-edit window. For example, you type a phonetic representation of a spoken word and the input method determines the ideographic character that is pronounced in that way. When more than one character meets the criteria, the input method displays a list of characters from which to select. Once you confirm a selection in the pre-edit area, the information is passed to the application.

Input methods can be defined by the platform vendor, an application, or a user. Information about available input methods and their features can be found in the documentation for the system or application that you are using.

An internationalized application can dynamically set its language environment when it is run. The design of the application defines what information is expected and how it is used to set the language environment. Typically, you can modify the language environment used by an application by specifying a language resource or a language environment variable. The exact method that you use to set the language environment for an application is defined by the application. Refer to the documentation for the application for specific information.


The AIXwindows system supports the standard X11R6 with the following exceptions:

Input Method Values:

Input Context Values:

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