bubble.c

/* cum pile with -std=c99 or c11 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define _POSIX_C_SOURCE 200809L
#include <time.h>

const struct timespec sleepytime = {0, 70000000};
const int bubble[] = {2, 3, 4, 5, 4, 3, 3, 2};

int main(int argc, char *argv[])
{
	size_t len = 0;
	for (int i = 1; i < argc; i++)
		len += 1 + strlen(argv[i]);
	char *buf = calloc(len, 1);
	for (int i = 1; i < argc; i++)
		strcat(strcat(buf, argv[i]), " ");
	buf[len - 1] = '\0';

	size_t rail = len * 2 + (sizeof bubble / sizeof (int));
	int *spaces = calloc(rail, sizeof (int));
	memcpy(spaces + len, bubble, sizeof bubble);
	
	// CSI Ps A  Cursor Up Ps Times (default = 1) (CUU).
	// More about xterm escapes: http://invisible-island.net/xterm/ctlseqs/ctlseqs.html
	printf("\n\033[1A");
	for (size_t s = len + (sizeof bubble / sizeof (int)); s; s--) {
		for (size_t t = 0; t < len; t++)
			printf("%*c", spaces[s + t], buf[t]);
		fflush(stdout);
		nanosleep(&sleepytime, NULL);
		putchar('\r');
	}
	// CSI Ps B  Cursor Down Ps Times (default = 1) (CUD).
	printf("\033[1B");

	free(buf);
	free(spaces);

	return 0;
}