#include <sys/ioctl.h>  #include <net/if.h>  #include <unistd.h>  #include <netinet/in.h>  #include <string.h>     int main()  {      struct ifreq ifr;      struct ifconf ifc;      char buf[2048];      int success = 0;         int sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);      if (sock == -1) {          printf("socket error\n");          return -1;      }         ifc.ifc_len = sizeof(buf);      ifc.ifc_buf = buf;      if (ioctl(sock, SIOCGIFCONF, &ifc) == -1) {          printf("ioctl error\n");          return -1;      }         struct ifreq* it = ifc.ifc_req;      const struct ifreq* const end = it + (ifc.ifc_len / sizeof(struct ifreq));      char szMac[64];      int count = 0;      for (; it != end; ++it) {          strcpy(ifr.ifr_name, it->ifr_name);          if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {              if (! (ifr.ifr_flags & IFF_LOOPBACK)) { // don't count loopback                  if (ioctl(sock, SIOCGIFHWADDR, &ifr) == 0) {                      count ++ ;                      unsigned char * ptr ;                      ptr = (unsigned char  *)&ifr.ifr_ifru.ifru_hwaddr.sa_data[0];                      snprintf(szMac,64,"%02X:%02X:%02X:%02X:%02X:%02X",*ptr,*(ptr+1),*(ptr+2),*(ptr+3),*(ptr+4),*(ptr+5));                      printf("%d,Interface name : %s , Mac address : %s \n",count,ifr.ifr_name,szMac);                  }              }          }else{              printf("get mac info error\n");              return -1;          }      }  }   

1,Interface name : eth0 , Mac address : 90:B1:1D:87:13:75  2,Interface name : virtac , Mac address : 52:54:00:96:E0:BF  3,Interface name : map , Mac address : 52:54:00:F2:FE:9C  4,Interface name : poi , Mac address : 52:54:00:1B:97:82  5,Interface name : vnet1 , Mac address : 52:54:00:05:14:E3