node.js: readline: How to read a file

In this post, I am going to show you how to read a file line by line using readline module.

Step 1: Get a createInterface instance by passing file read stream as input.

const rl = readline.createInterface({

    input: fs.createReadStream('sample.txt'),

    crlfDelay: Infinity

});

Step 2: Read the stream line by line by using ‘line’ event.

rl.on('line', (line) => {

    console.log(`Line from file: ${line}`);

});

Find the below working application.

HelloWorld.js

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

/* Create a createInterface instance by passing file read stream as input*/
const rl = readline.createInterface({
    input: fs.createReadStream('sample.txt'),
    crlfDelay: Infinity
});

rl.on('line', (line) => {
    console.log(`${line}`);
});

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