C Pocket Reference

Internationalization

The ANSI standard supports the development of C programs that are adaptable to language and country-specific customs, such as the formatting of currency strings. The ANSI library also provides two functions, the type lconv, and macros for dealing with locales. These are declared in the header file locale.h .

All programs start with the default locale “C”, which contains no country or language-specific information. During execution, the program can change to another locale and retrieve locale-specific information. Since most applications do not require the full range of locale-specific information, this information is classified into categories, as shown in Table 1-42.

Table 1-42. Locale categories

Category	Portions of the locale affected
LC_ALL	The entire locale, including all of the categories below
LC_COLLATE	Only the functions strcoll() and strxfrm()
LC_CTYPE	Functions for character processing, such as isalpha() and the multibyte functions
LC_MONETARY	The currency formatting information returned by localeconv()
LC_NUMERIC	The decimal point character used by input/output and string conversion functions, and the formatting of non-currency numeric information, as returned by localeconv()
LC_TIME	Formatting of date and time information by strftime()

The following function is used to adapt a program to a specific locale:

char *setlocale( int category, const char *name );

The argument category is one of the symbolic constants described ...