#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <net/if.h>

int get_dev_ip(char *dev, char ip[16])
{
	int sockfd;
	struct ifreq ifr;

	sockfd = socket(AF_INET, SOCK_DGRAM, 0);
	if (sockfd == -1) {
		perror("socket() ERROR");
		return -1;
	}

	ifr.ifr_addr.sa_family = AF_INET;
	strcpy(ifr.ifr_name, dev);

	if (ioctl(sockfd, SIOCGIFADDR, &ifr) == -1) {
		perror("ioctl(SIOCGIFADDR) ERROR");
		return -1;
	}
	sprintf(ip, "%s",
		inet_ntoa(((struct sockaddr_in *)&(ifr.ifr_addr))->sin_addr));

	close(sockfd);
	return 0;
}

int main(void)
{
	char eth0_ip[16];
	char eth1_ip[16];

	get_dev_ip("eth0", eth0_ip);
	get_dev_ip("eth1", eth1_ip);

	printf("eth0 ip: %s\n", eth0_ip);
	printf("eth1 ip: %s\n", eth1_ip);

	return 0;
}