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

int
main (int argc, char **argv)
{
  int clock = argc == 1 ? CLOCK_REALTIME : CLOCK_REALTIME_COARSE;
  for (unsigned int i = 1; i; i++)
    {
      struct timespec ts;
      if (clock_gettime (clock, &ts))
	{
	  perror ("clock_gettime");
	  return 1;
	}
      time_t x = time (0);
      if (x < ts.tv_sec)
	{
	  printf ("clock_gettime (%s, ...)"
		  " yielded a seconds count of %ld;\n"
		  "then time (0) yielded a seconds count of %ld,"
		  " which was %ld s earlier.\n"
		  "Time warp!\n",
		  (clock == CLOCK_REALTIME
		   ? "CLOCK_REALTIME"
		   : "CLOCK_REALTIME_COARSE"),
		  (long) ts.tv_sec, (long) x, (long) (ts.tv_sec - x));
	  return 1;
	}
    }
  return 0;
}