获取本地IP地址

程序功能：

本程序主要获取本地的IP地址

思路分析：

#include <stdio.h>

#include <sys/types.h>

#include <net/if.h>

#include <netinet/in.h>

#include <sys/socket.h>

#include <linux/sockios.h>

#include <sys/ioctl.h>

#include <arpa/inet.h>

#define BUFSIZE 128

int main(void)

{

int sock_fd;

struct ifconf conf;

struct ifreq *ifr;

struct sockaddr_in *sin;

char buff[BUFSIZE];

int num, i;

if( (sock_fd = socket(PF_INET, SOCK_DGRAM, 0))<0)

{

perror("socket");

return -1;

}

conf.ifc_len = BUFSIZE;

conf.ifc_buf = buff;

ioctl(sock_fd, SIOCGIFCONF, &conf); //获取所有接口的清单

num = conf.ifc_len / sizeof(struct ifreq);

ifr = conf.ifc_req;

for(i = 0; i < num; i++){

sin = (struct sockaddr_in *)(&ifr->ifr_addr);

ioctl(sock_fd, SIOCGIFFLAGS, ifr); //获取接口标志

if(((ifr->ifr_flags & IFF_LOOPBACK) == 0) && (ifr->ifr_flags & IFF_UP)){

printf("%s (%s)\n", ifr->ifr_name, inet_ntoa(sin->sin_addr));

}

ifr++;

}

}

运行结果：

注释：

1》//PF_INET<=>AF_INET AF = Address Family PF = Protocol Family; //SOCK_DGRAM：UDP

2》//SIOCGIFCONF 参见：http://www.cppblog.com/wgcno7/archive/2010/04/21/115963.html