# C 语言标准库头文件 locale.h

sudo apt install language-pack-zh-hans  # 安装中文语言包

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

int main(void) {
    // 1. 获取当前 locale
    char *old_locale = setlocale(LC_ALL, NULL);
    printf("当前locale: %s\n", old_locale);
    
    // 2. 设置为 zh_CN.UTF-8
    char *new_locale = setlocale(LC_ALL, "zh_CN.UTF-8");
    if (new_locale == NULL) {
        printf("无法设置locale\n");
        return 1;
    }
    printf("新locale: %s\n", new_locale);
    
    // 3. 演示数字格式
    printf("\n数字格式示例:\n");
    printf("本地格式: %'d\n", 123456789);
    printf("默认格式: %d\n", 123456789);
    
    // 4. 演示货币格式
    struct lconv *lc = localeconv();
    printf("\n货币格式示例:\n");
    printf("本地货币符号: %s\n", lc->currency_symbol);
    printf("正数货币格式: %s%.2f\n", lc->currency_symbol, 1234.56);
    
    // 5. 演示时间格式
    time_t t = time(NULL);
    struct tm *lt = localtime(&t);
    char time_str[100];
    
    strftime(time_str, sizeof(time_str), "%c", lt);
    printf("\n本地时间格式: %s\n", time_str);
    
    strftime(time_str, sizeof(time_str), "%x", lt);
    printf("本地日期格式: %s\n", time_str);
    
    strftime(time_str, sizeof(time_str), "%X", lt);
    printf("本地时间格式: %s\n", time_str);
    
    // 6. 恢复原始locale
    setlocale(LC_ALL, old_locale);
    
    return 0;
}