GPS时间(周、秒) 转 UTC 时间 C++版本

#include <ctime>
#include <iostream>
#include <chrono>
#include <time.h>






int main(int argc, const char *argv[])
{
    unsigned short    gps_week = 2322;
    double    gps_seconds = 112576.3;   //数值来自GPS设备

    double  gps_total_seconds = gps_week*7*24*60*60 + gps_seconds;

    // GPS 参考时间起点: 1980-01-06 00:00:00
    int  gps_year = 1980;
    int  gps_month = 1;
    int  gps_day = 6;

    std::tm tm{};
    tm.tm_year = gps_year - 1900;//1980;   //年从 1900年开始
    tm.tm_mon  = gps_month - 1;//1;     // 月从0开始: 0~11
    tm.tm_mday = gps_day;//6;
    tm.tm_hour = 0;
    tm.tm_min  = 0;
    tm.tm_sec  = 0;
    tm.tm_isdst = 0;
    std::time_t t = std::mktime(&tm) + 8*60*60;

    double  total_seconds = static_cast<double>(t) + gps_total_seconds;
    total_seconds -= 18;    //计算 GPS秒对应的时间差,GPS时间与UTC时间在秒上相差18秒

    std::cout<<"t:"<<t<<std::endl;
    printf("T:%f\n\n\n", total_seconds);

    time_t  tnow = static_cast<time_t>(total_seconds);
    std::tm * dt = gmtime(&tnow);

    //printf ( "The current date/time is: %s", asctime(dt) );
    printf("%d-%02d-%02d %02d:%02d:%02d\n", dt->tm_year+1900, \
            dt->tm_mon+1, dt->tm_mday, dt->tm_hour, dt->tm_min, dt->tm_sec);

    double  utc_time = 0.0;     // GPS UTC time: hhmmss.ss
    double ms = gps_seconds - static_cast<int64_t>(gps_seconds)*1.0;
    utc_time = dt->tm_hour*10000.0 + dt->tm_min*100.0 + dt->tm_sec + ms;

    return  0;
}