/* set of functions for time keeping */
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define	MAXSTRING	100

typedef struct {
  clock_t	begin_clock, save_clock;
  time_t	begin_time, save_time;
} time_keeper;

static time_keeper tk; /* known only to this file */

void start_time(void)
{
  tk.begin_clock = tk.save_clock = clock(); /* system time used in CLK_TCK */
  tk.begin_time = tk.save_time = time(); /* wall clock in secs since 1/1/70 */
}

double prn_time(void)
{
  char	s1[MAXSTRING], s2[MAXSTRING];
  int	field_width, n1, n2;
  double clocks_per_second = (double) CLOCKS_PER_SEC,
	 user_time, real_time;

  user_time = (clock() - tk.save_clock) / clocks_per_second;
  real_time = difftime(time(NULL), tk.save_time);
  tk.save_clock = clock();
  tk.save_time = time(NULL);

  /* print the values found in a neat format */

  n1 = sprintf(s1, "%.1f", user_time);
  n2 = sprintf(s2, "%.1f", real_time);
  field_width = (n1 > n2) ? n1 : n2;
  printf("%s%*.1f%s\n%s%*.1f%s\n\n",
	 "User time: ", field_width, user_time, " seconds",
	 "Real time: ", field_width, real_time, " seconds");
  return user_time;
}