fs in node js code example

Example 1: writefile in node js

// writefile.js

const fs = require('fs');

let lyrics = 'But still I\'m having memories of high speeds when the cops crashed\n' + 
             'As I laugh, pushin the gas while my Glocks blast\n' + 
             'We was young and we was dumb but we had heart';

// write to a new file named 2pac.txt
fs.writeFile('2pac.txt', lyrics, (err) => {
    // throws an error, you could also catch it here
    if (err) throw err;

    // success case, the file was saved
    console.log('Lyric saved!');
});

Example 2: node open file

const fs = require("fs");

// __dirname means relative to script. Use "./data.txt" if you want it relative to execution path.
fs.readFile(__dirname + "/data.txt", (error, data) => {
    if(error) {
        throw error;
    }
    console.log(data.toString());
});

Example 3: nodejs readfile

const fs = require('fs');

fs.readFile('/Users/joe/test.txt', 'utf8' , (err, data) => {
  if (err) {
    console.error(err);
    return
  }
  console.log(data);
});

Example 4: fs.writefile

const fs = require('fs');

fs.writeFile("/tmp/test", "Hey there!", function(err) {
    if(err) {
        return console.log(err);
    }
    console.log("The file was saved!");
}); 

// Or
fs.writeFileSync('/tmp/test-sync', 'Hey there!');

Example 5: read file in nodejs using fs

let myFile = "./myText.txt";
const fs = require("fs");
		
app.all('/test', async (req, res) => {
	try {
		const readData = fs.readFileSync(myFile, 'utf8');
		if (readData) {
			res.send(readData)
		}
	} catch (error) {
		res.send("something is wrong", error)
	}
})

Example 6: fs writefile node

const fs = require('fs')

const content = 'Some content!'

fs.writeFile('/Users/joe/test.txt', content, err => {
  if (err) {
    console.error(err)
    return
  }
  //file written successfully
})