一、Windows情形
转载自: http://blog.youkuaiyun.com/stpeace/article/details/12179021
我们可以在cmd中敲入ipconfig来获取本机ip地址,下面写个程序来获取本机ip地址(结果相同):
#include<stdio.h>
#include<winsock2.h>
#pragma comment(lib,"ws2_32.lib") // 静态库
void findIP(char *ip, int size)
{
WORD v = MAKEWORD(1, 1);
WSADATA wsaData;
WSAStartup(v, &wsaData); // 加载套接字库
struct hostent *phostinfo = gethostbyname("");
char *p = inet_ntoa (* ((struct in_addr *)(*phostinfo->h_addr_list)) );
strncpy(ip, p, size - 1);
ip[size - 1] = '\0';
WSACleanup( );
}
int main()
{
char ip[20] = {0};
findIP(ip, sizeof(ip));
printf("%s\n", ip);
return 0;
}
上面的程序仅仅获取一个ip, 那要获取所有ip, 怎么办呢? 很简单, 充分利用上面的list啊, 如下:
#include<stdio.h>
#include<winsock2.h>
#pragma comment(lib,"ws2_32.lib") // 静态库
void getIPs()
{
WORD v = MAKEWORD(1, 1);
WSADATA wsaData;
WSAStartup(v, &wsaData); // 加载套接字库
int i = 0;
struct hostent *phostinfo = gethostbyname("");
for(i = 0; NULL != phostinfo&& NULL != phostinfo->h_addr_list[i]; ++i)
{
char *pszAddr = inet_ntoa(*(struct in_addr *)phostinfo->h_addr_list[i]);
printf("%s\n", pszAddr);
}
WSACleanup( );
}
int main()
{
getIPs();
return 0;
}
二、Linux下情形
#include <stdio.h>;
#include <sys/types.h>;
#include <sys/socket.h>;
#include <sys/ioctl.h>;
#include <netinet/in.h>;
#include <net/if.h>;
#include <net/if_arp.h>;
#include <arpa/inet.h>;
#include <errno.h>;
#define ETH_NAME "eth0"
int main()
{
int sock;
struct sockaddr_in sin;
struct ifreq ifr;
sock = socket(AF_INET, SOCK_DGRAM, 0);
if (sock == -1)
{
perror("socket");
return -1;
}
strncpy(ifr.ifr_name, ETH_NAME, IFNAMSIZ);
ifr.ifr_name[IFNAMSIZ - 1] = 0;
if (ioctl(sock, SIOCGIFADDR, &ifr) < 0)
{
perror("ioctl");
return -1;
}
memcpy(&sin, &ifr.ifr_addr, sizeof(sin));
fprintf(stdout, "eth0: %s\n", inet_ntoa(sin.sin_addr));
return 0;
}