FD_ZERO
#define FD_ZERO(p) do { \
#define FD_ZERO(p) bzero((char *)(p), sizeof (*(p)))
#define FD_ZERO(s) (s) = 0
#define FD_ZERO(p) bzero((char *)(p), sizeof(*(p)))
#define FD_ZERO(p) (void) memset((void *)(p), 0, sizeof (*(p)))
#define FD_ZERO(p) bzero((char *)(p), sizeof (*(p)))
#undef FD_ZERO
#define FD_ZERO(maskp)
#define FD_ZERO(p) bzero((p), sizeof (*(p)))
#define FD_ZERO(__p) (void) _memset((__p), 0, sizeof (*(__p)))