fs read line by line code example

Example 1: get lines as list from file node js

const fs = require('fs');

fs.readFile('file.txt', function(err, data) {
    if(err) throw err;

    const arr = data.toString().replace(/\r\n/g,'\n').split('\n');

    for(let i of arr) {
        console.log(i);
    }
});

Example 2: node.js read text file line by line

const readline = require('readline');

const readInterface = readline.createInterface({
        input: fs.createReadStream('name.txt'),
        output: process.stdout,
        console: false
    });

 for await (const line of readInterface) {
        console.log(line);
    }
//or
readInterface.on('line', function(line) {
    console.log(line);
});

Example 3: node read file line

const fs = require('fs');
const readline = require('readline');

async function processLineByLine() {
  const fileStream = fs.createReadStream('input.txt');

  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 from file: ${line}`);
  }
}

processLineByLine();