Parse domain names using the adns library.

To use the adns library to resolve domain names, you need to follow these steps:

1. Install the adns library: The adns library is an asynchronous DNS resolution library in C language. You can download and compile it from the official website.
2. Include the adns header file: In your code file, use the statement #include to include the adns library’s header file.
3. Initialize the adns library: Use the adns_init() function at the beginning of the code to initialize the adns library.

adns_state adns;
adns_init(&adns, adns_if_noenv, NULL);

1. submit the adns

adns_query query;
adns_submit(&adns, "example.com", ns_t_a, ns_c_in, NULL, &query, callback);

The callback function is used to handle the results of DNS resolution, accepting multiple parameters such as the status of the query results and the data of the query results.

void callback(adns_answer *answer, int status, int dummy, void *arg) {
    // 处理解析结果
}

1. The DNS request was successful.
2. provide a response

if (status == adns_s_ok) {
    // 处理解析结果
    for (int i = 0; i < answer->nrrs; ++i) {
        struct in_addr addr;
        memcpy(&addr, answer->rrs[i].rdata, sizeof(addr));
        printf("IPv4 address: %s\n", inet_ntoa(addr));
    }
} else {
    // 处理解析错误
    printf("Failed to resolve domain name: %s\n", adns_strerror(status));
}

1. complete the operation

adns_finish(adns);

The above is the basic process of parsing domain names using the adns library. You can make appropriate modifications and extensions according to your own needs. Please note that the adns library is a low-level asynchronous DNS parsing library, which is relatively complex to use. You may need some basic knowledge of C language and network programming.