#include <stdio.h>

 #include <ifaddrs.h>

 #include <arpa/inet.h>

 #include <cstring>

 #define MAX_LENGTH 254

 int main(void)

 {

     char ipAddr[MAX_LENGTH];

     ipAddr[] = '\0';

     struct ifaddrs * ifAddrStruct = NULL;

     void * tmpAddrPtr = NULL;

     if (getifaddrs(&ifAddrStruct) != )

     {

         //if wrong, go out!

         printf("Somting is Wrong!\n");

         return -;

     }

     struct ifaddrs * iter = ifAddrStruct;

     while (iter != NULL) {

         if (iter->ifa_addr->sa_family == AF_INET) { //if ip4

             // is a valid IP4 Address

             tmpAddrPtr = &((struct sockaddr_in *)iter->ifa_addr)->sin_addr;

             char addressBuffer[INET_ADDRSTRLEN];

             inet_ntop(AF_INET, tmpAddrPtr, addressBuffer, INET_ADDRSTRLEN);

             if (strlen(ipAddr) + strlen(addressBuffer) < MAX_LENGTH - )

             {

                 if (strlen(ipAddr) > )

                 {

                      strcat(ipAddr, ";");

                 }

                 strcat(ipAddr, addressBuffer);

             }

             else

             {

                 printf("Too many ips!\n");

                 break;

             }

         }

         //else if (ifaddrstruct->ifa_addr->sa_family == af_inet6) { // check it is ip6

         /* deal ip6 addr */

         //    tmpaddrptr = &((struct sockaddr_in *)ifaddrstruct->ifa_addr)->sin_addr;

         //    char addressbuffer[inet6_addrstrlen];

         //    inet_ntop(af_inet6, tmpaddrptr, addressbuffer, inet6_addrstrlen);

         //}

         iter = iter->ifa_next;

     }

     //releas the struct

     freeifaddrs(ifAddrStruct);

     printf("The ips: %s\n", ipAddr);

     return ;

 }