__fd_mask 56 sys/select.h #define __NFDBITS ((unsigned)(sizeof(__fd_mask) * __NBBY)) /* bits per mask */ __fd_mask 60 sys/select.h __fd_mask fds_bits[__howmany(FD_SETSIZE, __NFDBITS)]; __fd_mask 79 sys/select.h #define fd_mask __fd_mask