Internet地址结构及转换

Internet地址的基本数据结构如下：

 

#include <netinet/in.h>

struct sockaddr_in {
    short            sin_family;      // e.g. AF_INET
    unsigned short   sin_port;  // e.g. htons(3490)
    struct in_addr   sin_addr;   // see struct in_addr, below
    char             sin_zero[8];    // zero this if you want to
};

struct in_addr {
    unsigned long s_addr;  // load with inet_aton()
};

 

 

IP字符串转换到unsigned long：

 

in_addr ip_addr;
inet_aton("63.161.169.137", &ip_addr);

 

unsigned long转换到IP字符串：

 

char ip[64];
in_addr in;
in.s_addr = htonl(176427304); //unsigned long to be converted
strcpy(ip, inet_ntoa(in));
printf("ip: %s\n", ip);

 

使用的时候只要include下面的头文件：

 

#include <netinet/in.h>
#include <arpa/inet.h>