/*
  8-bit ripple test.
  Usage: ripple [ w [ l ] ]
   w = screen line width, default 80, must be > 0, max 132.
   l = how many lines to display, default 1000; < 1 means go forever.
  Author: Frank da Cruz, Columbia University, 2000.
*/
char *crlf = "\015\012";

char p[512];

main(argc,argv) int argc; char *argv[]; {
    int i, j, c, w = 80, l = 1000;
    char beep = '\07';

    c = 32;
    for (i = 0; i < 94; i++)		/* Initialize display array */
      p[i] = c++;
    c = 160;
    for (i = 0; i < 96; i++)
      p[i+94] = c++;
    c = 32;
    for (i = 0; i < 94; i++)
      p[i+94+96] = c++;
    c = 160;
    for (i = 0; i < 96; i++)
      p[i+94+96+94] = c++;

    if (argc > 1)			/* User-specified width */
      w = atoi(argv[1]);
    if (argc > 2)			/* User-specified number of lines */
      l = atoi(argv[2]);
    if (w < 1 || w > 132)		/* Quit upon conversion error */
      exit(1);

    for (j = i = 0; l < 1 || i < l; i++) { /* Ripple loop */
	write(1, p+j, w);
	write(1, crlf, 2);
	if (++j == 190) j = 0;
    }
    write(1, &beep, 1);
    exit(0);
}