Pull a random word and definition from the Jargon File

jargonScraper.js

// NOTE:
// Must have xray installed.
// Use `npm init -y && npm install -S x-ray` in an empty directory.
// Here's the link for npm: https://docs.npmjs.com/getting-started/installing-node

// NOTE:
// Here's the url of the Jargon File: http://www.catb.org/jargon/html/

'use strict';

const fs = require('fs');
const path = require('path');
const Xray = require('x-ray');
const xray = Xray();

const homeUrl = 'http://www.catb.org/jargon/html/go01.html';
const outputFilename = path.join(__dirname, 'output.txt');

function getTerm(callback) {
    if (! callback) {
        throw new Error('No callback passed');
    }

    console.log('Searching...');
    xray(homeUrl, ['dd dl dt a@href'])( (err, urls) => {
        if (err) console.error(err);
        const chosenUrl = urls[Math.floor(Math.random() * urls.length)];

        xray(chosenUrl, ['dd'])( (err, definitions) => {
            if (err) console.error(err);
            const definition = definitions.join('\n\n').trim();

            xray(chosenUrl, '.navheader table tr th')( (err, title) => {
                if (err) console.error(err);
                return callback(title, definition);
            });
        });
    });
}

function standardizeLineLength(string, length) {
    string = string.replace(/\s+/g, ' ');
    string = string.replace('\n', '');
    const arr = string.split('');
    const lines = [];

    let start = 0;
    let end = length;
    while (true) {
        if (end > arr.length) {
            lines.push(arr.slice(start).join(''));
            break;
        }

        const line = arr.slice(start, end);
        const eol = line.lastIndexOf(' ');
        if (eol === -1) eol = length;
        lines.push(arr.slice(start, start + eol).join(''));

        start += eol + 1;
        end += eol + 1;
    }
    return lines.join('\n');
}

function main() {
    getTerm( (title, definition) => {
        const prettierDefinition = standardizeLineLength(definition, 75);
        const fullMsg = title.toUpperCase() + ':\n\n' + prettierDefinition;

        if (fullMsg.length > 300) main();

        fs.writeFile(outputFilename, fullMsg, (err) => {
            if (err) console.error(err);
        })
    });
}

main()

Can be used e.g. to set a cron job for updating your terminal's message of the day.