cpp get time now and its precision is microseconds

#include <chrono>
#include <ctime>
#include <iomanip>
#include <iostream>
#include <sstream>
#include <string>
#include <unistd.h>

using namespace std; 

std::string getTimeNow()
{
    using namespace std::chrono;

    // get current time
    auto now = system_clock::now();

    // get number of milliseconds for the current second
    // (remainder after division into seconds)
    auto ms = duration_cast<milliseconds>(now.time_since_epoch()) % 1000;

    // convert to std::time_t in order to convert to std::tm (broken time)
    auto timer = system_clock::to_time_t(now);

    // convert to broken time
    std::tm bt = *std::localtime(&timer);

    std::ostringstream oss;

    oss << std::put_time(&bt, "%Y%m%d%H%M%S") << std::setfill('0') << std::setw(3) << ms.count();

    return oss.str();
}

int main(int args,char **argv)
{
     for(int i=0;i<10;i++)
     {
        cout<<getTimeNow()<<endl;
        sleep(1);
     }
}

 

Compile

g++ -g -std=c++2a *.cpp -o h1

 

Run

./h1