通过Ioctl获取本机IP地址

#include <stdio.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>

int main()
{
    int i=0;
    int sockfd;

      struct ifconf ifconf;
      unsigned char buf[512];
      struct ifreq *ifreq;

      //初始化ifconf

      ifconf.ifc_len = 512;
      ifconf.ifc_buf = buf;

      if((sockfd = socket(AF_INET, SOCK_DGRAM, 0))<0)
      {
          perror("socket");
        exit(1);
    }

      ioctl(sockfd, SIOCGIFCONF, &ifconf);    //获取所有接口信息

  //接下来一个一个的获取IP地址

      ifreq = (struct ifreq*)buf;

      for(i=(ifconf.ifc_len/sizeof(struct ifreq)); i>0; i--)
    {
        printf("name = [%s]\n", ifreq->ifr_name);
          printf("local addr = [%s]\n",
        inet_ntoa(((struct sockaddr_in*)&(ifreq->ifr_addr))->sin_addr));
          ifreq++;
      }

    return 0;

}