nkhil

Parse a CSV file in node without dependencies

We're going to parse a file, use a conditional to add a new column, then save the new file with an additional column all without using any external dependencies not included in the standard lib

const fs = require('fs');

const inputCsvFile = 'input.csv';
const outputCsvFile = 'output.csv';

nkhil

Custom Karabiner rule to toggle W/A/S/D as arrow keys

The following rule re-maps the capslock key so it toggles on W/A/S/D becoming arrow keys.

{
  "global": {
    "check_for_updates_on_startup": true,
    "show_in_menu_bar": true,
    "show_profile_name_in_menu_bar": false,

nkhil

Symmetric decryption using Nodejs

This is a working example of symmetric encryption in nodejs.

From https://stackoverflow.com/questions/41043878/symmetric-encryption-with-nodejs

var assert = require('assert');
var crypto = require('crypto');
const fs = require('fs')

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import never from 'never'

type ParsedLogs = Array<[string, string]>

type GroupedLogs = {
  [K: string]: Array<string>
}

export default function main(logs: string) {
  const parsedLogs = parseAndNormaliseLogs(logs)

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function parseLogs(logs) {
  const logsArray = logs.split('\n').map(eachLog => eachLog.split(','))
  const normalisedArray = normaliseArray(logsArray)
  const logsWithSeconds = normalisedArray.map(([timestamp, phoneNumber]) =>
    [calculateTotalSeconds(timestamp), phoneNumber])
  const grouped = groupByPhoneNumber(logsWithSeconds)
  const phoneNumberWithLargestTotal = getPhoneNumberWithLargestTotalSeconds(grouped)
  grouped[phoneNumberWithLargestTotal] = 0
  return calculateTotalBill(logsWithSeconds, phoneNumberWithLargestTotal)
}

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const crypto = require('crypto')
const fs = require('fs')

const encryptedData = fs.readFileSync('encrypted_data.txt', { encoding: 'utf-8' })
const privateKey = fs.readFileSync('private.pem', { encoding: 'utf-8' })

const decryptedData = crypto.privateDecrypt(
  {
    key: privateKey,
    // In order to decrypt the data, we need to specify the

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const fs = require('fs')
const crypto = require('crypto')

const dataToEncrypt = fs.readFileSync('data_to_encrypt.txt', { encoding: 'utf-8' })

const publicKey = Buffer.from(fs.readFileSync('public.pem', { encoding: 'utf-8' }))

const encryptedData = crypto.publicEncrypt(
  {
    key: publicKey,

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const crypto = require('crypto')
const fs = require('fs')

const { publicKey, privateKey } = crypto.generateKeyPairSync("rsa", {
  // The standard secure default length for RSA keys is 2048 bits
  modulusLength: 2048,
})

// *********************************************************************
//

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const crypto = require('crypto')

const NUMBER_OF_BYTES = 32
const randomBytes = crypto.randomBytes(NUMBER_OF_BYTES)

nkhil

Here's how to create and export an RSA public/private key pair from Node.js

const crypto = require('crypto')
const fs = require('fs')

const { privateKey, publicKey } = crypto.generateKeyPairSync('rsa', {
  modulusLength: 2048,
})