util.c

#include <ares.h>

static void ares_wait(ares_channel channel){
    int nfds;
    fd_set readers, writers;
    struct timeval tv, *tvp;
	 
    while (1) {
        FD_ZERO(&readers);
        FD_ZERO(&writers);
        nfds = ares_fds(channel, &readers, &writers);
        if (nfds == 0)
            break;
        tvp = ares_timeout(channel, NULL, &tv);
        select(nfds, &readers, &writers, NULL, tvp);
        ares_process(channel, &readers, &writers);
    }
}