Minix1.1/user/test/test4.c

int pid0, pid1, pid2, pid3, s;
int i, fd;
int nextb;
char buf[1024];

main() {
  int k = 0;
  printf("Test  4 ");
  subr();
  printf("ok\n");
}


subr()
{
  if ( pid0 = fork()){
	/* Parent 0 */
	if (pid0 < 0) nofork();
	if ( pid1 = fork()) {
		/* Parent 1 */
		if (pid1 < 0) nofork();
		if (pid2 = fork()) {
			/* Parent 2 */
			if (pid2 < 0) nofork();
			if ( pid3 = fork()) {
				/* Parent 3 */
				if (pid3 < 0) nofork();
				for (i= 0; i<10000; i++) ;
				kill(pid2, 9);
				kill(pid1, 9);
				kill(pid0, 9);
				wait(&s);
				wait(&s);
				wait(&s);
				wait(&s);
			} else {
				fd = open("/dev/fd0", 0);
				lseek(fd, 20480L*nextb, 0);
				for (i= 0; i<10; i++) read(fd,buf,1024);
				nextb++;
				close(fd);
				exit(0);
			}
		} else {
			while (1) getpid();
		}
	} else {
		while (1) getpid();
	}
  } else {
	while (1) getpid();
  }
}

nofork()
{
  printf("Fork failed.  Not enough memory.\n");
  exit(1);
}