letter_counter.js

import { existsSync, readFileSync, createWriteStream, writeFileSync } from "fs";

const fileName = process.argv[2]
if (!existsSync(fileName)) {
  console.log("Can't find file " + fileName)
  process.exit(1)
}

const text = readFileSync(fileName, { encoding: 'utf-8' }).replace(/\r\n/g, "")
let totalLetters=0, totalLettersWithSpecialChars = 0
const letterCount = {}
const specialCharCount = {}
for (const i in text) {
  const char = text[i]
  totalLettersWithSpecialChars++
  if (char.match(/[A-Za-zĀ-ňЀ-џ]/g)) {
    totalLetters++
    letterCount[char.toUpperCase()] = (letterCount[char.toUpperCase()] + 1) || 1
  } else {
    specialCharCount[char] = (specialCharCount[char] + 1) || 1
  }
}
writeFileSync("./letter-summary.txt", "")
const writeStream = createWriteStream("./letter-summary.txt")

/**
 * @param {String} text 
 * @param {Number} newLine 0-brak 1-tylko plik 2-zawsze
 */
function log(text, newLine) {
  process.stdout.write(text + (newLine == 2 ? "\n" : ""))
  writeStream.write(text + (newLine > 0 ? "\n" : ""))
}

const letters = Object.keys(letterCount).sort()
const specialChars = Object.keys(specialCharCount).sort()
log("Total letters: " + totalLetters, 2)
log("Total chars: " + totalLettersWithSpecialChars, 2)
log("Letter count:", 2)
for (const i in letters) {
  const letter = letters[i]
  const amount = letterCount[letter]
  log(`${letter}: ${amount} (${Math.round(amount/totalLetters * 1000) / 10}%) `, 1)
}

log("\n\nLetter count with special chars:", 2)

for (const i in letters) {
  const letter = letters[i]
  const amount = letterCount[letter]
  log(`${letter}: ${amount} (${Math.round(amount / totalLettersWithSpecialChars * 1000) / 10}%) `, 1)
}
const charNames = {
  " ": "SPACE",
  ",": "COMMA",
  ";": "SEMICOLON",
  ":": "COLON",
  ".": "DOT"
}
for (const i in specialChars) {
  const char = specialChars[i]
  const amount = specialCharCount[char]
  log(`${charNames[char] || char}: ${amount} (${Math.round(amount / totalLettersWithSpecialChars * 1000) / 10}%) `, 1)
}