static gethostbyname with libcares

ares.c

#include <ares.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netdb.h>
#include <stdarg.h>
#include <string.h>
#include <ctype.h>
#include <unistd.h>

// gcc -static ares.c -lcares -o ares

static void state_cb(void *data, int s, int read, int write) {
    printf("Change state fd %d read:%d write:%d\n", s, read, write);
}


static void callback(void *arg, int status, int timeouts, struct hostent *host) {

    if (!host || status != ARES_SUCCESS) {
        printf("Failed to lookup %s\n", ares_strerror(status));
        return;
    }
    char buff[INET_ADDRSTRLEN];
    inet_ntop(host->h_addrtype, host->h_addr_list[0], buff, sizeof(buff));
    memcpy(arg, buff, strlen(buff));
}

static void wait_ares(ares_channel channel) {
    for (; ;) {
        struct timeval *tvp, tv;
        fd_set read_fds, write_fds;
        int nfds;

        FD_ZERO(&read_fds);
        FD_ZERO(&write_fds);
        nfds = ares_fds(channel, &read_fds, &write_fds);
        if (nfds == 0) {
            break;
        }
        tvp = ares_timeout(channel, NULL, &tv);
        select(nfds, &read_fds, &write_fds, NULL, tvp);
        ares_process(channel, &read_fds, &write_fds);
    }
}

int mygethostbyname(char *host, char *ip) {
    ares_channel channel;
    int status;
    struct ares_options options;
    int optmask = 0;

    status = ares_library_init(ARES_LIB_INIT_ALL);
    if (status != ARES_SUCCESS) {
        printf("ares_library_init: %s\n", ares_strerror(status));
        return 0;
    }
    //options.sock_state_cb_data;
    options.sock_state_cb = state_cb;
    optmask |= ARES_OPT_SOCK_STATE_CB;

    status = ares_init_options(&channel, &options, optmask);
    if (status != ARES_SUCCESS) {
        printf("ares_init_options: %s\n", ares_strerror(status));
        return 0;
    }

    ares_gethostbyname(channel, host, AF_INET, callback, ip);

    wait_ares(channel);
    ares_destroy(channel);
    ares_library_cleanup();
    ip[strlen(ip)] = 0;
    return 0;
}

int main() {

    char *host = "google.com";
    char ip[16];


    getipbyhost(host, ip);

    printf("IP [%s]\n", ip);

    return 0;

}