adns_state   adns;

adns_query   query;

adns_answer   *answer;

函数原型：

int adns_init(adns_state *newstate_r, adns_initflags flags, FILE *diagfile /*0=>stderr*/);

举例：

adns_init(&adns, adns_if_noenv, 0);

函数原型：

int adns_submit(adns_state ads,

        const char *owner,

        adns_rrtype type,

        adns_queryflags flags,

        void *context,

        adns_query *query_r);

举例：

adns_submit(adns,   argv[1],   adns_r_a,  (adns_queryflags) 0,   NULL,   &query);

函数原型：

int adns_check(adns_state ads,

           adns_query *query_io,

           adns_answer **answer_r,

           void **context_r);

例：adns_check(adns,   &query,   &answer,   NULL);

函数原型：

int adns_wait(adns_state ads,

          adns_query *query_io,

          adns_answer **answer_r,

          void **context_r);

例：adns_wait(adns,   &query,   &answer,   NULL);

函数原型：

void adns_finish(adns_state ads);

例：adns_finish(adns);

#include "adns.h" 

#include <sys/errno.h> 

#include <sys/socket.h>                    

#include <netinet/in.h>                      

#include <arpa/inet.h> 

int test_dns(char *host)   

{ 

    adns_state ads; 

    adns_initflags flags;   

    flags = adns_if_nosigpipe | adns_if_noerrprint; 

    adns_init(&ads, flags, NULL); 

    adns_query quer = NULL; 

    adns_submit(ads, host, (adns_rrtype) adns_r_a, (adns_queryflags) 0, NULL, &quer); 

    int tryCount = -1; 

    int adns_cname = 0; 

    while(tryCount < 32) { 

        tryCount += 1; 

        adns_answer *ans; 

        int res = adns_check(ads, &quer, &ans, NULL); 

        if(res == 0) {       

            if (ans->status == adns_s_prohibitedcname) { 

                char cname[128]; 

                strncpy(cname, ans->cname, 127); 

                cname[strlen(ans->cname)] = '\0';       

                adns_query quer = NULL; 

                adns_submit(ads, cname, (adns_rrtype) adns_r_addr, (adns_queryflags) 0, NULL, &quer);       

                adns_cname = 1; 

            } else { 

                //resolve IPv4 address      

               /*

　　　　　　　　 * if(adns_cname) 

               *     printf("ip: %s\n", ans->status == adns_s_ok ? inet_ntoa(ans->rrs.addr->addr.inet.sin_addr) : "no"); 

               *     else 

               *     printf("ip: %s\n", ans->status == adns_s_ok ? inet_ntoa(*(ans->rrs.inaddr)) : "no"); 

               */

                //resolve IPv6 address

                if(adns_cname){

                    if(ans->status == adns_s_ok){

                        char buf[INET6_ADDRSTRLEN];

                        inet_ntop(AF_INET6, &ans->rrs.addr->addr.inet6.sin6_addr, buf, sizeof(buf));

                        printf("ip: %s\n", buf);

                    }

                    else{

                         printf("no\n");

                     }

                 }

                 else{

                     if(ans->status == adns_s_ok){

                         char buf[INET6_ADDRSTRLEN];

                         inet_ntop(AF_INET6, ans->rrs.in6addr, buf, sizeof(buf));

                         printf("ip: %s\n", buf);

                     }

                     else{

                          printf("no\n");

                     }

                 }

                 adns_finish(ads); 

                 break; 

            }                   

        }        

        else if (res == ESRCH || res == EAGAIN) { 

            sleep(1); 

        } else { 

            printf("host(%s) is err!\n", host); 

        } 

    }   

    return 0; 

} 

int main(int argc, char *argv[]) { 

    char host[128]; 

    while(1) { 

        scanf("%s", host); 

        if(strlen(host) == 3 && strcmp(host, "eof")) break; 

        test_dns(host); 

    } 

    return 0; 

}                    

CFLAGS= -g 

TARGETS=libadns.a 

LIBOBJS=types.o event.o query.o reply.o general.o setup.o transmit.om parse.o poll.o check.o 

all: testdns 

testdns: testdns.c libadns.a 

libadns.a: $(LIBOBJS) 

                rm -f $@ 

                $(AR) cq $@ $(LIBOBJS) 

clean: 

        rm -f $(LIBOBJS) libadns.a *~ config.status 

distclean: clean 

        rm -f config.h .depend   

$(LIBOBJS):     adns.h internal.h config.h