NFDBITS
for (sock = 0; sock < maxsize; sock += NFDBITS) {
ibitsp = (fd_set *)calloc(howmany(sock_max, NFDBITS),
memcpy(ibitsp, fdbitsp, howmany(sock_max, NFDBITS) *
fdbitsp = (fd_set *)calloc(howmany(sock_max, NFDBITS),
char smallbits[howmany(FD_SETSIZE, NFDBITS) *
nd -= fb * NFDBITS; /* the number of excess fds */
for (i = 0; i < nfd; i += NFDBITS) {
fdsn = howmany(sock + 1, NFDBITS) * sizeof(fd_mask);