#include <iostream>
#include <unistd.h>   // getpid
#include <time.h>     // for nanosleep

#include <signal.h>  // for signal, don't worry about this yet.

using namespace std;


static void Handler(int) {
   cout << "\t\tBRRRRRIIIINNNNGGGGG!!!!!!!!" << endl;
   return;
}

int main(int argc, char * argv[]) {

    timespec want, left ={0,0};

    want.tv_sec = 5;
    want.tv_nsec = 0;

    if (argc > 1) {
        want.tv_sec = static_cast<time_t> (atoi(argv[1]));
    }

    // bad, there are better ways to do this.
    // Don't worry about this for now.
    // This is for demo purposes only.
    signal(SIGUSR1, Handler);

    pid_t mypid = getpid();

    cout << "Hello, this is process " << mypid << endl;

    do {
       cout << "\tTrying to sleep for " << want.tv_sec << " seconds " 
            << want.tv_nsec << " nanoseconds" << endl;
       if (-1 == nanosleep(&want, & left) ) {

          cout << "\tShoot, someone got me up early, "
	       << left.tv_sec << " seconds " << left.tv_nsec
	       << " nanoseconds left" << endl;
	  cout << endl;
       } 
       want = left;
       // left is not changed on success, reset it for next pass.
       left = {0,0};
    } while (want.tv_sec > 0 and want.tv_nsec > 0);

    cout << "All done sleeping " << endl;

    return 0;
}