#include <stdio.h>
#include <pthread.h>
#include <unistd.h>
#include <string.h>

void *write_thread(void *arg)
{
	int n = (int)arg;
	const int rows = 12;
	const int cols = 79;
	char buf[64];
	for (int i=0; i<1; i++) {
		for (int r=1; r<=rows; r++) {
			for (int c=1; c<=cols; c++) {
				sprintf(buf, "\033[%d;%dH\033[%dm%c", r + n*rows, c, 31+n, 'A'+n);
				write(1, buf, strlen(buf));
			}
		}
	}
}

int main()
{
	pthread_t th1, th2;

	printf("\033[H\033[J");
	fflush(stdout);
	if (pthread_create(&th1, NULL, write_thread, (void*)0)) {
		perror ("1: pthred_create");
		return -1;
	}
	if (pthread_create(&th2, NULL, write_thread, (void*)1)) {
		perror ("2: pthred_create");
		return -1;
	}
	pthread_join(th1, NULL);
	pthread_join(th2, NULL);
	usleep(3000000);
	printf("\033[H\033[J\033[m");
	fflush(stdout);
	return 0;
}