server linux

#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <errno.h>
#include <ifaddrs.h>
#include <netdb.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#define PORT 3550
#define BACKLOG 2 /* Max allowed connections */

int main(int argc, char *argv[])
{
   /* Get local address */
   struct ifaddrs *ifaddr, *ifa;
   char host[512] = {0};

   if (getifaddrs(&ifaddr) == -1) {
         printf("error getting local IP address: %i\n", strerror(errno));
   } else {
       for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
            getnameinfo(ifa->ifa_addr, sizeof(struct sockaddr_in), host, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);

            if((strcmp(ifa->ifa_name,"lo")!=0) && (ifa->ifa_addr->sa_family == AF_INET) ) {
               printf(" Interface : <%s>\n", ifa->ifa_name );
               printf("   Address : <%s>\n", host);
            }
      }
      freeifaddrs(ifaddr);
   }


   int fd, fd2; /* file descriptors */

   struct sockaddr_in server;
   /* server address info */

   struct sockaddr_in client;
   /* client address info */

   int sin_size;

   if ((fd=socket(AF_INET, SOCK_STREAM, 0)) == -1 ) {
      printf("socket() error\n");
      exit(-1);
   }

   server.sin_family = AF_INET;

   server.sin_port = htons(PORT);

   server.sin_addr.s_addr = INADDR_ANY;
   /* connect to any IP*/

   bzero(&(server.sin_zero),8);


   if (bind(fd,(struct sockaddr*)&server,
           sizeof(struct sockaddr))==-1) {
      printf("bind() error\n");
      exit(-1);
   }


   if (listen(fd,BACKLOG) == -1) {
      printf("listen() error\n");
      exit(-1);
   }

   while(1) {
      sin_size = sizeof(struct sockaddr_in);

      printf ("\nWaiting for a 3DS...\n");

      if ((fd2 = accept(fd,(struct sockaddr *)&client,
                        &sin_size))==-1) {
         printf("error en accept()\n");
         exit(-1);
      }

      printf("We got connection from: %s\n",
             inet_ntoa(client.sin_addr) );
      /* show client IP */

      send(fd2,"Welcome to my server.\n",22,0);
      /* send a message to the client */

      close(fd2); /* close fd2 */
   }
}