struct tm tm_time;

strptime(time.c_str(), "%Y%m%d %H:%M:%S", &tm_time);

time_t tt = mktime(&tm_time);

mktime()  python time模块也有这个函数。

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char buffer[128];
    time_t now = time(NULL);
    struct tm *timeinfo = localtime(&now);
    strftime(buffer, sizeof(buffer), "%Y-", timeinfo);
    printf("year=%s\n", buffer);
    std::string year(buffer);

std::string str_time = year + what[1];

        struct tm tm_time;
        strptime(str_time.c_str(), "%Y-%m-%d %H:%M:%S", &tm_time);
        time_t tt = mktime(&tm_time);