#include <sys/types.h>

#include <sys/socket.h>

#include <arpa/inet.h>

     char IPdec[]; //存放点分十进制IP地址

     struct in_addr s; // IPv4地址结构体

     printf("Please input IP address: ");

     scanf("%s", IPdec); //input 192.168.1.1

 

     inet_pton(AF_INET, IPdec, (void *)&s);



     printf("inet_pton: 0x%x\n", s.s_addr); // output-> inet_pton: 0x101a8c0

     inet_ntop(AF_INET, (void *)&s, IPdec, );  

     printf("inet_ntop: %s\n", IPdec); //output-> inet_ntop 192.168.1.1

struct in_addr{

　　in_addr_t s_addr;

}

in_addr_t 一般为 32位的unsigned int，其字节顺序为网络顺序（network byte ordered)，即该无符号整数采用大端字节序^[1]。.