C

DNS Query MX Records

See more DNS Examples

Shows how to perform a DNS query to retrieve MX records.

Note: This example requires Chilkat v9.5.0.96 or later.

C

#include <C_CkDns.h>
#include <C_CkJsonObject.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkDns dns;
    HCkJsonObject json;
    const char *name;
    int ttl;
    int pref;
    const char *domain;
    int i;
    int count_i;

    success = FALSE;

    dns = CkDns_Create();

    json = CkJsonObject_Create();
    CkJsonObject_putEmitCompact(json,FALSE);

    success = CkDns_Query(dns,"MX","somebody@gmail.com",json);
    if (success == FALSE) {
        printf("%s\n",CkDns_lastErrorText(dns));
        CkDns_Dispose(dns);
        CkJsonObject_Dispose(json);
        return;
    }

    printf("%s\n",CkJsonObject_emit(json));

    // Sample response.
    // Parsing code below..

    // -------------------------------------------------------------------------------
    // Note: Chilkat will return the results sorted by "pref" from lowest to highest.
    // -------------------------------------------------------------------------------

    // {
    //   "answer": {
    //     "mx": [
    //       {
    //         "name": "gmail.com",
    //         "ttl": 491,
    //         "pref": 5,
    //         "domain": "gmail-smtp-in.l.google.com"
    //       },
    //       {
    //         "name": "gmail.com",
    //         "ttl": 491,
    //         "pref": 10,
    //         "domain": "alt1.gmail-smtp-in.l.google.com"
    //       },
    //       {
    //         "name": "gmail.com",
    //         "ttl": 491,
    //         "pref": 20,
    //         "domain": "alt2.gmail-smtp-in.l.google.com"
    //       },
    //       {
    //         "name": "gmail.com",
    //         "ttl": 491,
    //         "pref": 30,
    //         "domain": "alt3.gmail-smtp-in.l.google.com"
    //       },
    //       {
    //         "name": "gmail.com",
    //         "ttl": 491,
    //         "pref": 40,
    //         "domain": "alt4.gmail-smtp-in.l.google.com"
    //       }
    //     ]
    //   }
    // }

    // Use this online tool to generate parsing code from sample JSON: 
    // Generate Parsing Code from JSON

    i = 0;
    count_i = CkJsonObject_SizeOfArray(json,"answer.mx");
    while (i < count_i) {
        CkJsonObject_putI(json,i);
        name = CkJsonObject_stringOf(json,"answer.mx[i].name");
        ttl = CkJsonObject_IntOf(json,"answer.mx[i].ttl");
        pref = CkJsonObject_IntOf(json,"answer.mx[i].pref");
        domain = CkJsonObject_stringOf(json,"answer.mx[i].domain");
        i = i + 1;
    }



    CkDns_Dispose(dns);
    CkJsonObject_Dispose(json);

    }