(Objective-C) DNS Query A Records

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

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

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#import <CkoDns.h>
#import <CkoJsonObject.h>
#import <NSString.h>

CkoDns *dns = [[CkoDns alloc] init];

CkoJsonObject *json = [[CkoJsonObject alloc] init];
json.EmitCompact = NO;

BOOL success = [dns Query: @"A" domain: @"microsoft.com" answer: json];
if (success == NO) {
    NSLog(@"%@",dns.LastErrorText);
    return;
}

NSLog(@"%@",[json Emit]);

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

// {
//   "answer": {
//     "a": [
//       {
//         "name": "microsoft.com",
//         "ttl": 1528,
//         "ipv4": "20.112.250.133"
//       },
//       {
//         "name": "microsoft.com",
//         "ttl": 1528,
//         "ipv4": "20.231.239.246"
//       },
//       {
//         "name": "microsoft.com",
//         "ttl": 1528,
//         "ipv4": "20.76.201.171"
//       },
//       {
//         "name": "microsoft.com",
//         "ttl": 1528,
//         "ipv4": "20.70.246.20"
//       },
//       {
//         "name": "microsoft.com",
//         "ttl": 1528,
//         "ipv4": "20.236.44.162"
//       }
//     ]
//   }
// }

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

NSString *name = 0;
int ttl;
NSString *ipv4 = 0;

int i = 0;
int count_i = [[json SizeOfArray: @"answer.a"] intValue];
while (i < count_i) {
    json.I = [NSNumber numberWithInt: i];
    name = [json StringOf: @"answer.a[i].name"];
    ttl = [[json IntOf: @"answer.a[i].ttl"] intValue];
    ipv4 = [json StringOf: @"answer.a[i].ipv4"];
    i = i + 1;
}