C localization functions

In computing, C localization functions are a group of functions in the C programming language implementing basic localization routines. The functions are used in multilingual programs to adapt to the specific locale. In particular, the way of displaying of numbers and currency can be modified. These settings affect the behaviour of input/output functions in the C Standard Library.

Criticism

C standard localization functions are criticized because the localization state is stored globally. This means that in a given program all operations involving a locale can use only one locale at a time. As a result, it is very difficult to implement programs that use more than one locale.

Overview of functions

C localization functions and types are defined in locale.h (clocale header in C++).

struct lconv

• explain formatting monetary and other numeric values.

char* decimal point;

• decimal point for non-monetary values

char* grouping;

• size pf digit groups for non-monetary values

struct lconv* localeconv(void);
char* setlocale(int, const char*); charthousand sep;

• separator for non-monetary values

char* currency symbol;

• currency symbol

char* int curr symbol;

• international currency symbol

char*mon-decimal point

• decimal point for monetary values

char* mon grouping;

• sizes of digit groups for monetary values

char* mon thousand sep;

• separator for digit groups for monetary values

Example

#include <stdio.h>
#include <stdlib.h>
#include <locale.h>

int main(void)
{/* Locale is set to "C" before this. This call sets it
       to the "current locale" by reading environment variables: */
    setlocale(LC_ALL, "");

    const struct lconv * const currentlocale = localeconv();

    printf("In the current locale, the default currency symbol is: %s\n",
        currentlocale->currency_symbol);

    return EXIT_SUCCESS;}