1 /* 2 ** USEFUL.H -- Some useful stuff. 3 ** 4 ** @(#)useful.h 3.1 03/07/81 5 */ 6 7 # define bool char 8 # define TRUE 1 9 # define FALSE 0 10 11 # ifndef NULL 12 # define NULL 0 13 # endif NULL 14 15 # define setbit(bit, word) (word |= bit) 16 # define clrbit(bit, word) (word &= ~bit) 17 # define bitset(bit, word) ((word) & (bit)) 18