STRTBLINCR
#define allocsize(size) (((size) + 1 + STRTBLINCR - 1) & ~(STRTBLINCR - 1))
static struct strhdr strtblhdr[allocsize(NAME_MAX) / STRTBLINCR];
np = strtblhdr[len / STRTBLINCR].next;
strtblhdr[len / STRTBLINCR].next = np->next;
tp = &strtblhdr[strlen(name) / STRTBLINCR];