哪位大侠，知道关于linux的gethostbyname获取多个IP?

linux下的gethostbyname只读取etc下hosts里的主机名及第一个IP，
现在如果要得到两个IP且能够当用户用ifconfig修改后，再调用这个函数时得以的两个IP是新的IP地址，这么作　　　　　　

以前在 www.chinaunix.net 看到的
rh8下编译通过
gethostbyname是php和asp等里面的吧
#include <stdio.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <net/if_arp.h>

#define MAXINTERFACES   16

main (argc, argv)
register int argc;
register char *argv[];
{
  register int fd, intrface, retn = 0;
  struct ifreq buf[MAXINTERFACES];
  struct arpreq arp;
  struct ifconf ifc;

  if ((fd = socket (AF_INET, SOCK_DGRAM, 0)) >= 0) {
     ifc.ifc_len = sizeof buf;
     ifc.ifc_buf = (caddr_t) buf;
     if (!ioctl (fd, SIOCGIFCONF, (char *) &ifc)) {
        intrface = ifc.ifc_len / sizeof (struct ifreq);
printf("interface num is intrface=%d\n\n\n",intrface);
while (intrface-- > 0)
{
   printf ("net device %s\n", buf[intrface].ifr_name);

/*Jugde whether the net card status is promisc*/
   if (!(ioctl (fd, SIOCGIFFLAGS, (char *) &buf[intrface]))) {
      if (buf[intrface].ifr_flags & IFF_PROMISC) {
puts("the interface is PROMISC");
retn++;
      }
   } else {
      char str[256];

      sprintf (str, "cpm: ioctl device %s", buf[intrface].ifr_name);
      perror (str);
   }

/*Jugde whether the net card status is up*/
   if (buf[intrface].ifr_flags & IFF_UP) {
   puts("the interface status is UP");
      }
   else {
   puts("the interface status is DOWN");
   }

/*Get IP of the net card */
   if (!(ioctl (fd, SIOCGIFADDR, (char *) &buf[intrface])))
{
puts ("IP address is:");
puts(inet_ntoa(((struct sockaddr_in *)(&buf[intrface].ifr_addr))->sin_addr));
puts("");
  //puts (buf[intrface].ifr_addr.sa_data);
}
   else {
      char str[256];

      sprintf (str, "cpm: ioctl device %s", buf[intrface].ifr_name);
      perror (str);
  }

/*Get HW ADDRESS of the net card */
       if (!(ioctl (fd, SIOCGIFHWADDR, (char *) &buf[intrface])))
{
puts ("HW address is:");

printf("%02x:%02x:%02x:%02x:%02x:%02x\n",
(unsigned char)buf[intrface].ifr_hwaddr.sa_data[0],
(unsigned char)buf[intrface].ifr_hwaddr.sa_data[1],
(unsigned char)buf[intrface].ifr_hwaddr.sa_data[2],
(unsigned char)buf[intrface].ifr_hwaddr.sa_data[3],
(unsigned char)buf[intrface].ifr_hwaddr.sa_data[4],
(unsigned char)buf[intrface].ifr_hwaddr.sa_data[5]);

puts("");
puts("");
}

   else {
      char str[256];

      sprintf (str, "cpm: ioctl device %s", buf[intrface].ifr_name);
      perror (str);
  }
}
     } else
        perror ("cpm: ioctl");

  } else
     perror ("cpm: socket");

   close (fd);
   return retn;
}