NIL
#define NIL ((Node *)0)
#define NIL ((struct entry *)(0))
#define NIL 0
#define NIL -1
#undef NIL
#define NIL ((struct name *)0) /* The nil pointer for namelists */
#define NIL ((char *)0)
#define NIL 0
#define NIL 0
#define NIL(s) (((s) != 0) ? (s) : "<nil>")
#define NIL ((Freehdr) 0)
#define NIL 0
#define NIL 0
NIL = 0,
#define NIL 0