Defined in header <locale.h>  |  ||
|---|---|---|
 #define LC_ALL /*implementation defined*/  |  ||
 #define LC_COLLATE /*implementation defined*/  |  ||
 #define LC_CTYPE /*implementation defined*/  |  ||
 #define LC_MONETARY /*implementation defined*/  |  ||
 #define LC_NUMERIC /*implementation defined*/  |  ||
 #define LC_TIME /*implementation defined*/  |  
Each of the above macro constants expand to integer constant expressions with distinct values that are suitable for use as the first argument of setlocale.
| Constant | Explanation | 
|---|---|
 LC_ALL  |  selects the entire C locale | 
 LC_COLLATE  |  selects the collation category of the C locale | 
 LC_CTYPE  |  selects the character classification category of the C locale | 
 LC_MONETARY  |  selects the monetary formatting category of the C locale | 
 LC_NUMERIC  |  selects the numeric formatting category of the C locale | 
 LC_TIME  |  selects the time formatting category of the C locale | 
Additional macro constants, with names that begin with LC_ followed by at least one uppercase letter, may be defined in locale.h. For example, the POSIX specification requires LC_MESSAGES (which controls, among other things, perror and strerror), ISO/IEC 30112:2014 (2014 draft) additionally defines LC_IDENTIFICATION, LC_XLITERATE, LC_NAME, LC_ADDRESS, LC_TELEPHONE, LC_PAPER, LC_MEASUREMENT, and LC_KEYBOARD, which are supported by the GNU C library (except for LC_XLITERATE).
#include <stdio.h>
#include <locale.h>
#include <time.h>
#include <wchar.h>
 
int main(void)
{
    setlocale(LC_ALL, "en_US.UTF-8"); // the C locale will be the UTF-8 enabled English
    setlocale(LC_NUMERIC, "de_DE.utf8");   // decimal dot will be German
    setlocale(LC_TIME, "ja_JP.utf8");      // date/time formatting will be Japanese
    wchar_t str[100];
    time_t t = time(NULL);
    wcsftime(str, 100, L"%A %c", localtime(&t));
    wprintf(L"Number: %.2f\nDate: %Ls\n", 3.14, str);
}Possible output:
Number: 3,14 Date: 月曜日 2017年09月25日 13時00分15秒
|  gets and sets the current C locale  (function)  | 
|
| C++ documentation for locale categories | |
    © cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
    https://en.cppreference.com/w/c/locale/LC_categories