thread_locale1.c - Per-thread locale demo
Posted by Anonymous on Tue 31st Jan 2023 12:43
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/*
 * thread_multi_locale1.c - Per-thread locale demo
 *
 * Written by Roland Mainz <roland.mainz@nrubsig.org>
 */

#define _XOPEN_SOURCE 700

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

#ifdef __GLIBC__
/* { BSD, MacOSX, Illumos, ... } do not need this! */
#define CURSED_GLIBC_DOES_NOT_HAVE_PRINTF_L
#endif

#ifdef CURSED_GLIBC_DOES_NOT_HAVE_PRINTF_L
#include <stdarg.h>
#include <errno.h>
#endif /* CURSED_GLIBC_DOES_NOT_HAVE_PRINTF_L */

#ifdef CURSED_GLIBC_DOES_NOT_HAVE_PRINTF_L
/* cursed glibc does not provide |printf_l()| */
int vprintf_l(locale_t loc, const char *format, va_list ap)
{
        locale_t prev_loc;
        int ret;
        int saved_errno;

        prev_loc = uselocale(loc);

        ret = vprintf(format, ap);
        saved_errno = errno;

        (void)uselocale(prev_loc);

        errno = saved_errno;
        return ret;
}

int printf_l(locale_t loc, const char *format, ...)
{
        va_list args;
        int res;

        va_start(args, format);
        res = vprintf_l(loc, format, args);
        va_end(args);

        return res;
}
#endif /* CURSED_GLIBC_DOES_NOT_HAVE_PRINTF_L */


int main(int ac, char *av[])
{
        locale_t my_en_l;
        locale_t my_de_l;
        double x;

        (void)puts("# thread_multi_locale1: start");

        my_en_l = newlocale(LC_ALL_MASK, "en_US.UTF-8", NULL);
        my_de_l = newlocale(LC_ALL_MASK, "de_DE.UTF-8", NULL);

        if ((my_en_l == (locale_t)0) || (my_de_l == (locale_t)0)) {
                perror("Could not create locale object");
                return EXIT_FAILURE;
        }

        x = 123456.789123456789;
        (void)printf_l(my_en_l, "%8.8f\n", x);
        (void)printf_l(my_de_l, "%8.8f\n", x);

        /*
         * If we use |uselocale()| we must set the current thread
         * locale to something else before freeing the current
         * locale_t object!!
         */
        freelocale(my_de_l);
        freelocale(my_en_l);

        (void)puts("# thread_multi_locale1: done.");

        return EXIT_SUCCESS;
}