1、将UNIX时间戳转为东八区时间字符串

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

void unix_timestamp_to_string(time_t timestamp, char* time_string) {
    struct tm * timeinfo;
    timestamp = 8*3600+timestamp;
    timeinfo = localtime(&timestamp);
    //timeinfo->tm_hour += 8; // 增加8小时来获取东八区时间
    strftime(time_string, 20, "%Y-%m-%d %H:%M:%S", timeinfo);
}

int main() {
    time_t timestamp = 1609459200; // 2021年1月1日08:00:00,UTC时间
    char time_string[80];

    unix_timestamp_to_string(timestamp, time_string);
    printf("Converted time: %s\n", time_string);

    return 0;
}

2、将时间字符串（无分隔符）转为UNIX时间戳

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

time_t string_to_unix_timestamp(const char *time_str) {
    struct tm tm_time = {0}; // 初始化 tm 结构体
    
    // 解析时间字符串
    if (sscanf(time_str, "%4d%2d%2d%2d%2d",
               &tm_time.tm_year, &tm_time.tm_mon, &tm_time.tm_mday,
               &tm_time.tm_hour, &tm_time.tm_min) != 5) {
        printf("Invalid data\n");
        return 0;
    }

    // 由于 tm_year 表示的是自 1900 年起的年数，需要减去 1900
    tm_time.tm_year -= 1900;
    // 减去 1 来使月份从 0 开始，即 0 表示 1 月
    tm_time.tm_mon -= 1;

    // 将 tm 结构体转换为时间戳并返回
    return mktime(&tm_time);
}

int main() {
    const char *time_str = "202203121030";
    time_t timestamp = string_to_unix_timestamp(time_str);

    if (timestamp != 0) {
        printf("Unix timestamp: %ld\n", timestamp);
    }

    return 0;
}

3、将将时间字符串（含分隔符-，：）转为UNIX时间戳

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

time_t string_to_unix_timestamp(char *time_str) {
    struct tm tm;
    time_t timestamp;

    strptime(time_str, "%Y-%m-%d %H:%M:%S", &tm); // 解析时间字符串
    timestamp = mktime(&tm); // 转换为时间戳

    return timestamp;
}

int main() {
    char time_str[] = "2022-03-12 10:30:00";
    time_t timestamp = string_to_unix_timestamp(time_str);

    if (timestamp != -1) {
        printf("Unix timestamp: %ld\n", timestamp);
        struct tm *timeinfo = localtime(&timestamp);
        printf("Converted time: %s\n", asctime(timeinfo));
    } else {
        printf("Invalid data\n");
    }

    return 0;
}

4、获取系统中的东八区时间

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

void get_local_time() {
    time_t rawtime;
    struct tm * timeinfo;
    char buffer[80];

    time(&rawtime);
    timeinfo = localtime(&rawtime);
    strftime(buffer, 80, "%Y-%m-%d %H:%M:%S", timeinfo);
    
    printf("Local time: %s\n", buffer);
}

int main() {
    get_local_time();

    return 0;
}