get host ip

getip.cpp

#include <sys/types.h>
#include <ifaddrs.h>
#include <netinet/in.h>
#include <arpa/inet.h>

bool getIP(string &ip)
{
    struct ifaddrs *ifa_buf = NULL;     /// /usr/include/ifaddrs.h
    struct ifaddrs *ifa_iter = NULL;
    void *tmp_addr_ptr = NULL;

    getifaddrs(&ifa_buf);

    for (ifa_iter = ifa_buf; ifa_iter != NULL; ifa_iter = ifa_iter->ifa_next) {
        if (ifa_iter->ifa_addr->sa_family == AF_INET) { // IPv4
            tmp_addr_ptr = &((struct sockaddr_in*)ifa_iter->ifa_addr)->sin_addr;
            char host_buffer[INET_ADDRSTRLEN];
            inet_ntop(AF_INET, tmp_addr_ptr, host_buffer, INET_ADDRSTRLEN);
            if (strncmp(host_buffer, "127.0.0.1",sizeof("127.0.0.1")) == 0)
                continue;
            ip.assign(host_buffer);
            return true;
        }
    }

    return false;
}