promises.lookupService - Node documentation
function promises.lookupService

Usage in Deno

import { promises } from "node:dns";
const { lookupService } = promises;
lookupService(
address: string,
port: number,
): Promise<{ hostname: string; service: string; }>

Resolves the given address and port into a host name and service using the operating system's underlying getnameinfo implementation.

If address is not a valid IP address, a TypeError will be thrown. The port will be coerced to a number. If it is not a legal port, a TypeError will be thrown.

On error, the Promise is rejected with an Error object, where err.code is the error code.

const dnsPromises = require('node:dns').promises;
dnsPromises.lookupService('127.0.0.1', 22).then((result) => {
  console.log(result.hostname, result.service);
  // Prints: localhost ssh
});

Parameters

address: string
port: number

Return Type

Promise<{ hostname: string; service: string; }>