Node.js: how to send Whois requests without using the shell

In this tutorial we will see how to make requests to a WHOIS server in Node.js without using the shell.

The solution is to create a socket to the remote host on port 43 (for example whois.nic.it) passing the domain name and ending the request with the sequence \r\n.

'use strict';

const net = require('net');

const sendWhoisRequest = ({ host, domain }) => {
    const client = new net.Socket();
    const msg = domain + '\r\n';

    return new Promise((resolve, reject) => {

        client.connect(43, host, () => {
            client.write(msg);
        });

        client.on('data', data => {
            resolve(data.toString());
            client.destroy();
        });

        client.on('error', err => {
            reject(err);
        });

    });
};

This way we avoid using the whois command from the shell.