#include<string.h>
#include<arpa/inet.h>
#include<stdio.h>


int main(void){

	char ip[]="1.2.3.4";//字符串
	
	struct sockaddr_in server_addr;
	inet_pton(AF_INET,ip,&server_addr.sin_addr.s_addr);//字符串 to 网络字节序
	printf("s_addr : %x\n",server_addr.sin_addr.s_addr);

	printf("s_addr from to host : %x\n",ntohl(server_addr.sin_addr.s_addr));//网络字节序 to 主机字节序

	char server_ip[64];
	inet_ntop(AF_INET,&server_addr.sin_addr.s_addr,server_ip,64);//网络字节序 to 字符串

	printf("server ip : %s\n",server_ip);

	return 0;
}

 结果: