/*
 * from ftp://ftp.netbsd.org/pub/NetBSD/misc/gmcgarry/bench/execbench.tar.gz
 */
#define errx(x,y...) { fprintf(stderr, y); fprintf(stderr, "\n"); exit(x); }

#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
#include <unistd.h>

int
main(int argc, char *argv[])
{
        struct timeval before, after;
        unsigned long time, elapsed;
        char timestr[12], iterstr[12];
        char *timeptr, *countptr;
        int iter, count;

        if (argc < 2)
                errx(1, "Usage: %s iterations", argv[0]);

        iter = atoi(argv[1]);
        if (iter > 0) {  
                gettimeofday(&before, NULL);
                time = 1000000 * before.tv_sec + before.tv_usec;
                sprintf(timestr,"%lu", time);
                timeptr = timestr;
                countptr = argv[1];
        } else {
                iter = atoi(argv[2]);
                timeptr = argv[3];
                countptr = argv[4];
        } 

        if (iter != 0) {
                iter--;
                sprintf(iterstr, "%d", iter);
                execl(argv[0], argv[0], "0", iterstr, timeptr, countptr, NULL);
                errx(1, "execl failed");
        }

        gettimeofday(&after, NULL);
        sscanf(argv[3],"%lu", &time);
        count = atoi(argv[4]);
        elapsed = 1000000 * after.tv_sec + after.tv_usec;
        elapsed -= time;

        printf("time: %lu microseconds\n", elapsed / count);

        return (1);
}