======
c-ares
======

----------
Test suite
----------

c-ares can be smoke-tested with the following file, taken from this source (https://gist.github.com/mopemope/992777)::

    #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>

    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;
        }

        printf("Found address name %s\n", host->h_name);
        char ip[INET6_ADDRSTRLEN];
        int i = 0;

        for (i = 0; host->h_addr_list[i]; ++i) {
            inet_ntop(host->h_addrtype, host->h_addr_list[i], ip, sizeof(ip));
            printf("%s\n", ip);
        }
    }

    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
    main(void)
    {
        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 1;
        }
        //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 1;
        }

        ares_gethostbyname(channel, "google.com", AF_INET, callback, NULL);
        //ares_gethostbyname(channel, "google.com", AF_INET6, callback, NULL);
        wait_ares(channel);
        ares_destroy(channel);
        ares_library_cleanup();
        printf("fin\n");
        return 0;
    }


Code to compile and start script:

::

  g++ test.c  -l cares && ./a.out