void clear_bit(char bit_array[], unsigned bit_number) {
bit_array[character_offset(bit_number)] &= ~(1 << bit_offset(bit_number));
}
void set_bit(char bit_array[], unsigned bit_number) {
/*
** During the operator priority,shifting will be done before bitwise 'OR'.
*/
bit_array[character_offset(bit_number)] |= 1 << bit_offset(bit_number);
}
//测试特定位的值
int test_bit( char bit_array[], unsigned bit_number )
{
return (bit_array[ character_offset( bit_number ) ]& 1 << bit_offset( bit_number )) != 0;
}