Node.js | dns.resolveCname() Method

The dns.resolveCname() method is an inbuilt application programming interface of the dns module which is used to resolve CNAME records for the specified hostname using DNS protocol.

Syntax:

dns.resolveCname( hostname, callback )

Parameters: This method has two parameters as mentioned above and described below:

  • hostname: This parameter specifies a string which denotes the hostname to be resolved.
  • callback: It specifies a function to be called after DNS resolution of the hostnames.
    • error: It specifies error if generated.
    • addresses: It is an array of string that signifies the returned cname addresses for the hostname.

Return Value: This method returns error, addresses through callback function, These data are passed as parameters to the callback function.

Below examples illustrate the use of dns.resolveCname() method in Node.js:



Example 1:

filter_none

edit
close

play_arrow

link
brightness_4
code

// Node.js program to demonstrate the   
// dns.resolveAny() method
  
// Accessing dns module
const dns = require('dns');
  
// Calling dns.resolveCname() method for hostname
// geeksforgeeks.org and displaying them in
// console as a callback
dns.resolveCname('geeksforgeeks.org', (err, 
    addresses) => console.log('addresses: %j', addresses));

chevron_right


Output:

QueryReqWrap {
  bindingName: 'queryCname',
  callback: [Function],
  hostname: 'geeksforgeeks.org',
  oncomplete: [Function: onresolve],
  ttl: false,
  channel: ChannelWrap {} }
addresses: undefined

Example 2:

filter_none

edit
close

play_arrow

link
brightness_4
code

// Node.js program to demonstrate the   
// dns.resolveAny() method
  
// Accessing dns module
const dns = require('dns');
  
// Calling dns.resolveCname() method for hostname
// geeksforgeeks.org and displaying them in
// console as a callback
dns.resolveCname('localhost', (err, 
    addresses) => console.log('addresses: %j', addresses));

chevron_right


Output:

QueryReqWrap {
  bindingName: 'queryCname',
  callback: [Function],
  hostname: 'localhost',
  oncomplete: [Function: onresolve],
  ttl: false,
  channel: ChannelWrap {} }
addresses: undefined

Note: The above program will compile and run by using the node index.js command.

Reference: https://nodejs.org/api/dns.html#dns_dns_resolvecname_hostname_callback

My Personal Notes arrow_drop_up

Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.


Article Tags :

Be the First to upvote.


Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.