+/* ip address */
+char *
+ip(const char *interface)
+{
+ struct ifaddrs *ifaddr, *ifa;
+ int s;
+ char host[NI_MAXHOST];
+
+ /* check if getting ip address works */
+ if (getifaddrs(&ifaddr) == -1)
+ {
+ fprintf(stderr, "Error getting IP address.");
+ return smprintf("n/a");
+ }
+
+ /* get the ip address */
+ for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next)
+ {
+ if (ifa->ifa_addr == NULL)
+ continue;
+
+ s = getnameinfo(ifa->ifa_addr, sizeof(struct sockaddr_in), host, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
+
+ if ((strcmp(ifa->ifa_name, interface) == 0) && (ifa->ifa_addr->sa_family == AF_INET))
+ {
+ if (s != 0)
+ {
+ fprintf(stderr, "Error getting IP address.");
+ return smprintf("n/a");
+ }
+ return smprintf("%s", host);
+ }
+ }
+
+ /* free the address */
+ freeifaddrs(ifaddr);
+
+ /* return n/a if nothing works */
+ return smprintf("n/a");
+}
+