network interface의 link 상태를 점검하고 싶습니다.

#include <stdio.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include "wdscd.h"


int devcheck(char *dev)
{
   int fd;
   int strl;
   struct sockaddr *sa;
   struct sockaddr_in *sin;
   struct ifreq ifr;

   fd = socket(PF_INET,SOCK_STREAM,0);
   if (fd == -1) {
      pdebug("socket() failed");
      return -1;
   }
       
   /* Copy the interface name into the buffer */
   strncpy(ifr.ifr_name,dev,IFNAMSIZ);
        
   if (ioctl(fd,SIOCGIFADDR,&ifr)) {
      pdebug("device is not up/online");
      oldaddr = 0; // Kludges r' us?
      return -1;
   }
   /* Now the buffer will contain the information we requested */
   sa = (struct sockaddr *)&(ifr.ifr_addr);
   if (sa->sa_family == AF_INET) {
      sin = (struct sockaddr_in*) sa;
      if (inet_addr(inet_ntoa(sin->sin_addr)) != oldaddr) {
   	 oldaddr = inet_addr(inet_ntoa(sin->sin_addr));
         strl = strlen(inet_ntoa(sin->sin_addr)); 
         strncpy(coldaddr,inet_ntoa(sin->sin_addr),strl);
         close(fd);
         return 1;
      } else {
         close(fd);
         return 0;
      }
   } else {
      pdebug("Unknown Address Family");
   }

   close(fd);
   return -1;
}

네트웍 플밍을 해본적이 워낙 오래되어서.. 이게 맞는지 모르겠네요..

근데.. 왜 내 답변을 해주는 사람이 없는지...

input > eth0
output> 3Com Ethernet (etherenet model name)

howto ?