Little test program to write out timestamps in ASCII as fast as possible (for testing ISS writing data issues)

iss-ascii-data-printer.cpp

//
//  ascii-data-printer
//
//  Created by Stuart Campbell on 3/9/18.
//  Copyright © 2018 Stuart Campbell. All rights reserved.
//

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

#include <thread>
#include <chrono>

//const int NUM_SECONDS = 10;

int main(int argc, const char * argv[]) {
    long long sleep_duration = 100;
    if ( argc != 2 ) { // argc should be 2 for correct execution
        // We print argv[0] assuming it is the program name
        std::cout<<"usage: "<< argv[0] <<" <sleep-duration-in-usec>\n" <<std::endl;
        std::cout << " Using a default time of 100 usec" << std::endl;
    }
    else {
        sleep_duration = (long long)(argv[1]);
    }
    
    while(true)
    {
        std::chrono::time_point<std::chrono::system_clock> now = std::chrono::system_clock::now();
        auto nanoseconds = std::chrono::duration_cast<std::chrono::nanoseconds>(now.time_since_epoch());

        std::this_thread::sleep_for(std::chrono::microseconds(sleep_duration));
    
        //std::cout << nanoseconds.count() << std::endl;
        
        printf("%lld\n", nanoseconds.count());
    }
    
    return 0;
}