node script to check expiration date of a list of https domains

certage.js

#!/usr/bin/env node
//jshint node: true, esversion: 6, strict: global, indent: 4, immed: true, undef: true, sub: true, newcap: false
'use strict';

const fs = require('fs'),
    readline = require('readline'),
    https = require('https'),
    now = Date.now(),
    c = {
        reset:  '\x1b[0m',
        blue:   '\x1b[34m',
        yellow: '\x1b[33m',
        red:    '\x1b[31m',
    },
    list = __dirname + '/domains.txt';

function pad(len, str) {
    if (str.length > len)
        return str.slice(0, len - 1) + '\u2026';
    return str + ' '.repeat(len - str.length);
}

function lpad(len, str) {
    if (str.length > len)
        return '\u2026' + str.slice(0, len - 1);
    return ' '.repeat(len - str.length) + str;
}

if (!fs.existsSync(list)) {
    console.log('Create a file named domains.txt with the list of domains to check, one per line.');
    process.exit(1);
}

let max = 0;
readline.createInterface({
    input: fs.createReadStream(list)
}).on('line', (dom) => {
    max = Math.max(max, dom.length);
}).on('close', () => {
    ++max;
    console.log(c.blue + pad(max, 'Dominio'), pad(10, 'Date'), lpad(9, 'Expires') + ' ', pad(30, 'Issuer'), 'Subject Alternative Name' + c.reset);
    readline.createInterface({
        input: fs.createReadStream(list)
    }).on('line', (dom) => {
        dom = dom.trim();
        if (!dom.length)
            return;
        try {
            https.get('https://' + dom + '/', function (res) {
                const cert = res.socket.getPeerCertificate(),
                    date = new Date(cert.valid_to),
                    days = Math.floor((date - now) / 86400000),
                    color = days > 60 ? '' : days > 22 ? c.yellow : c.red;
                console.log(pad(max, dom), color + date.toISOString().slice(0, 10), lpad(9, days + ' days') + c.reset + ' ', pad(30, cert.issuer.CN), cert.subjectaltname);
            }).on('error', (e) => {
                console.log(pad(max, dom), c.red + 'ERROR' + c.reset);
            });
        } catch (e) {
            console.log(pad(max, dom), c.red + 'ERROR' + c.reset);
        }
    });
});