#include <locale.h>
locale_t newlocale(int category_mask, const char *locale,
locale_t base);
void freelocale(locale_t locobj);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
newlocale(), freelocale():
If base is the special locale object LC_GLOBAL_LOCALE (see duplocale(3)), or is not (locale_t) 0 and is not a valid locale object handle, the behavior is undefined.
The category_mask argument is a bit mask that specifies the locale categories that are to be set in a newly created locale object or modified in an existing object. The mask is constructed by a bitwise OR of the constants LC_ADDRESS_MASK, LC_CTYPE_MASK, LC_COLLATE_MASK, LC_IDENTIFICATION_MASK, LC_MEASUREMENT_MASK, LC_MESSAGES_MASK, LC_MONETARY_MASK, LC_NUMERIC_MASK, LC_NAME_MASK, LC_PAPER_MASK, LC_TELEPHONE_MASK, and LC_TIME_MASK. Alternatively, the mask can be specified as LC_ALL_MASK, which is equivalent to ORing all of the preceding constants.
For each category specified in category_mask, the locale data from locale will be used in the object returned by newlocale(). If a new locale object is being created, data for all categories not specified in category_mask is taken from the default ("POSIX") locale.
The following preset values of locale are defined for all categories that can be specified in category_mask:
Once a locale object has been freed, the program should make no further use of it.
Having created and initialized the locale object, the program then applies it using uselocale(3), and then tests the effect of the locale changes by:
The following shell sessions show some example runs of this program.
Set the LC_NUMERIC category to fr_FR (French):
$ ./a.out fr_FR 123456,789 Fri Mar 7 00:25:08 2014
Set the LC_NUMERIC category to fr_FR (French), and the LC_TIME category to it_IT (Italian):
$ ./a.out fr_FR it_IT 123456,789 ven 07 mar 2014 00:26:01 CET
Specify the LC_TIME setting as an empty string, which causes the value to be taken from environment variable settings (which, here, specify mi_NZ, New Zealand Māori):
$ LC_ALL=mi_NZ ./a.out fr_FR "" 123456,789 Te Paraire, te 07 o Poutū-te-rangi, 2014 00:38:44 CET
#define _XOPEN_SOURCE 700
#include <stdio.h>
#include <stdlib.h>
#include <locale.h>
#include <time.h>
#define errExit(msg) do { perror(msg); exit(EXIT_FAILURE); \
} while (0)
int
main(int argc, char *argv[])
{
char buf[100];
time_t t;
size_t s;
struct tm *tm;
locale_t loc, nloc;
if (argc < 2) {
fprintf(stderr, "Usage: %s locale1 [locale2]\n", argv[0]);
exit(EXIT_FAILURE);
}
/* Create a new locale object, taking the LC_NUMERIC settings
from the locale specified in argv[1] */
loc = newlocale(LC_NUMERIC_MASK, argv[1], (locale_t) 0);
if (loc == (locale_t) 0)
errExit("newlocale");
/* If a second command-line argument was specified, modify the
locale object to take the LC_TIME settings from the locale
specified in argv[2]. We assign the result of this newlocale()
call to 'nloc' rather than 'loc', since in some cases, we might
want to preserve 'loc' if this call fails. */
if (argc > 2) {
nloc = newlocale(LC_TIME_MASK, argv[2], loc);
if (nloc == (locale_t) 0)
errExit("newlocale");
loc = nloc;
}
/* Apply the newly created locale to this thread */
uselocale(loc);
/* Test effect of LC_NUMERIC */
printf("%8.3f\n", 123456.789);
/* Test effect of LC_TIME */
t = time(NULL);
tm = localtime(&t);
if (tm == NULL)
errExit("time");
s = strftime(buf, sizeof(buf), "%c", tm);
if (s == 0)
errExit("strftime");
printf("%s\n", buf);
/* Free the locale object */
freelocale(loc);
exit(EXIT_SUCCESS);
}