实现一个对8bit数据指定某一位置0或1

#include<stdio.h>

void bit_set(unsigned char *p_date, unsigned char position, int flag)
{
	if (flag == 1)
	{
		*p_date |= (1 << (position - 1));//0000 0010或0000 0001
	}                                   // 0000 0011
	else if (flag = 0)
	{
		*p_date &= ~(1 << (position - 1));//0000 0010&1111 1110
	}                                    // 0000 0010

}

int main()
{
	unsigned char val = 2;
	bit_set(&val, 1, 0);
	printf("%d\n", val);
	getchar();
	return 0;
}