Script to manipulate line by line

index.js

// TO swithc amt0 and amt1 that got switched up when creating this file
const fs = require('fs');
const readline = require('readline');
const { EOL } = require('os');

async function processLineByLine() {
  const fileStream = fs.createReadStream(__dirname + '/manipulate.txt');

  const writeStream = fs.createWriteStream(__dirname + '/good_manipulate.txt', {
    encoding: 'utf8',
  });

  const rl = readline.createInterface({
    input: fileStream,
    crlfDelay: Infinity,
  });
  // Note: we use the crlfDelay option to recognize all instances of CR LF
  // ('\r\n') in input.txt as a single line break.

  for await (const line of rl) {
    // Each line in input.txt will be successively available here as `line`.
    // console.log(`${line.split(',')[0]}`);
    
    // Given a line of CSV
    const [hash, blocktime, pool, sender, amt1, amt0] = line.split(',');
    
    // Re-arrange the CSV as required and write it back to a file
    const str = `${hash},${blocktime},${pool},${sender},${amt0},${amt1}`;
    writeStream.write(`${str}${EOL}`);
  }
}

processLineByLine();