#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <termios.h>
#include <time.h>
#include <unistd.h>

double atime() {
	struct timespec now;
	clock_gettime(CLOCK_REALTIME, &now);
	return now.tv_sec + now.tv_nsec * 1e-9;
}

int main() {
	double *wt;
	int c, l, t, ttyfd, wi, *wl, ws;
	struct termios orig, raw;

	ws = 100; /* allocated number of words */
	wl = malloc(ws * sizeof(int)); /* word lengths */
	if (wl == NULL) err(1, "malloc");
	wt = malloc(ws * sizeof(double)); /* word times */
	if (wt == NULL) err(1, "malloc");

	l = 0; /* current word length */
	wi = 0; /* number of current word in order */

	/* enter "raw" mode */
	ttyfd = open("/dev/tty", O_RDWR);
	if (ttyfd == -1) err(1, "open");
	tcgetattr(ttyfd, &orig);
	raw = orig;
	raw.c_lflag &= ~(ICANON);
	tcsetattr(ttyfd, TCSANOW, &raw);

	/* read loop */
	while ((c = getchar()) != EOF) {
		if (l == 0)
			t = atime(); /* current word time */
		if (c == ' ' || c == '\n') {
			wl[wi] = l;
			wt[wi] = atime() - t;
			l = 0;
			wi++;
		} else
			l++;
		if (c == '\n')
			break;
	}

	/* print statistics */
	double tt = 0;
	int tl = 0;
	for (int i = 0; i < wi; i++) {
		tt += wt[i];
		tl += wl[i];
	}
	printf("%f seconds per word\n", tt / wi);
	printf("%f seconds per word character\n", tt / tl);

	/* restore original terminal settings */
	tcsetattr(ttyfd, TCSANOW, &orig);
}