1.思维导图

2.指针形式验证大小端存储

#include<myhead.h>

int main(int argc, const char *argv[])
{
	int num = 0x12345678;

	char* ptr = (char *)&num;
	if(*ptr == 0x12)
	{
		printf("big endian\n");
	}
	else if(*ptr == 0x78)
	{
		printf("little endian\n");
	}

	return 0;
}

3.共用体形式验证大小端存储

#include<myhead.h>

int main(int argc, const char *argv[])
{
	union Endian
	{
		int num;
		char ch;
	}data;

	data.num = 0x12345678;
	if(data.ch = 0x12)
	{
		printf("big endian\n");
	}
	else if(data.ch == 0x78)
	{
		printf("little endian\n");
	}

	return 0;
}

4.主机字节序与网络字节序转换

#include<myhead.h>

int main(int argc, const char *argv[])
{
	unsigned int num = 0x12345678;

	unsigned short value = 0x1234;
	unsigned int num1 = htonl(num);
	unsigned short value1 = htons(value);

	printf("num1 = %#x\n",num1);
	printf("value1 = %#x\n",value1);

	return 0;
}

5.点分十进制

#include<myhead.h>

int main(int argc, const char *argv[])
{
	char *ip = "192.126.125.194";

	in_addr_t ip_test = inet_addr(ip);

	printf("ip_test = %#x\n",ip_test);

	printf("对应的主机字节序为：%#x\n",ntohl(ip_test));


	return 0;
}

6.手动实现将小端存储的数据转换成大端存储

#include<myhead.h>

int main(int argc, const char *argv[])
{
	int num = 0x12345678;
	char *ptr = (char*)&num;

	if(*ptr == 0x12)
	{
		printf("big endian\n");
	}
	else if(*ptr == 0x78)
	{
		printf("little endian\n");
	}
	
	char *qtr = ptr+3;
	while(qtr > ptr)
	{
		char temp = *ptr;
		*ptr = *qtr;
		*qtr = temp;
		ptr++;
		qtr--;
	}
	printf("num = %#x\n",num);

	return 0;
}