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

#include <string>
#include <vector>
using namespace std;

string getIPAddress()
{
    BOOL success;
    struct ifaddrs * addrs;
    const struct ifaddrs * cursor;
    
    success = getifaddrs(&addrs) == 0;
    if (success) {
        cursor = addrs;
        while (cursor != NULL) {
            // the second test keeps from picking up the loopback address
            if (cursor->ifa_addr->sa_family == AF_INET && (cursor->ifa_flags & IFF_LOOPBACK) == 0)
            {
                NSString *name = [NSString stringWithUTF8String:cursor->ifa_name];
                if ([name rangeOfString:@"en" options:NSCaseInsensitiveSearch].length > 0) {
                    string ipaddr = [[NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)cursor->ifa_addr)->sin_addr)]UTF8String];
                    if (!ipaddr.empty()) {
                        return ipaddr;
                    }
                }
            }
            cursor = cursor->ifa_next;
        }
        freeifaddrs(addrs);
    }
    return "";
}