Get ip address from an interface name

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>

#include <arpa/inet.h>
#include <net/if.h>

#include <unistd.h>

#define inaddrr(x) (*(struct in_addr *) &ifr->x[sizeof sa.sin_port])
#define IFRSIZE   ((int)(size * sizeof (struct ifreq)))

typedef char ip_address[15+1];

static int
get_addr(char * ifname,ip_address theip) {

  struct ifreq*ifr;
  struct ifreqifrr;
  struct sockaddr_insa;
  struct sockaddrifaddr;
  intsockfd;

  if((sockfd=socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP))==-1)
  {
printf ("Socket for DGRAM cannot be created/n");
return -1;
  }

  ifr = &ifrr;

  ifrr.ifr_addr.sa_family = AF_INET;

  strncpy(ifrr.ifr_name, ifname, sizeof(ifrr.ifr_name));

  if (ioctl(sockfd, SIOCGIFADDR, ifr) < 0) {
    printf("No %s interface./n", ifname);
    return -1;
  }

  ifaddr = ifrr.ifr_addr;
     strncpy(theip,inet_ntoa(inaddrr(ifr_addr.sa_data)),sizeof(ip_address));

  return 0;

}

int main(void){
ip_addresstheip;

if (get_addr("eth0",theip)==0)
      printf("The ip for eth0 is:%s/n",theip);
        else 
              printf("Couldn't get ip adress for eth0/n");
return 0;
}