#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <error.h>
#include <errno.h>

void stopwatch(double wait_time)
{
  time_t t1, t2;

  for (t1 = t2 = time(NULL); difftime(t2, t1) < wait_time; t2 = time(NULL))
    ;
}

int
main(int argc, char **argv)
{
  FILE *fp;
  char buf[100];
  double wait_time;

  if (argc != 2)
    error(EXIT_FAILURE, errno, "need filename");

  if ((fp = fopen(argv[1], "r")) == NULL)
    error(EXIT_FAILURE, errno, "fopen: ");

  while (fscanf(fp, "%lf%100s", &wait_time, buf) != EOF)
  {
    printf("%s\n", buf);
    stopwatch(wait_time);
  }

  return 0;
}