Create file based on buffer data in nodejs

Question

I am sending from front end client side a file, on the server side I have something like this:

{ name: 'CV-FILIPECOSTA.pdf',
  data: <Buffer 25 50 44 46 2d 31 2e 35 0d 25 e2 e3 cf d3 0d 0a 31 20 30 20 6f 62 6a 0d 3c 3c 2f 4d 65 74 61 64 61 74 61 20 32 20 30 20 52 2f 4f 43 50 72 6f 70 65 72 ... >,
  encoding: '7bit',
  mimetype: 'application/pdf',
  mv: [Function: mv] }

What I need is to create the file may be based on that buffer that is there, how can I do it?

I already searched a lot and didn't find any solution.

This is what I tried so far:

router.post('/upload', function(req, res, next) {
  if(!req.files) {
    return res.status(400).send("No Files were uploaded");
  }
  var curriculum = req.files.curriculum; 
  console.log(curriculum);
  curriculum.mv('../files/' + curriculum.name, function(err) {
    if (err){
      return res.status(500).send(err);      
    }
    res.send('File uploaded!');
  });
});

Suhail Gupta · Accepted Answer · 2017-09-15T12:02:49.083

13

You could use Buffer available with NodeJS:

let buf = Buffer.from('this is a test');
// buf equals <Buffer 74 68 69 73 20 69 73 20 61 20 74 65 73 74>

let str = Buffer.from(buf).toString();
// Gives back "this is a test"

Encoding could also be specified in the overloaded from method.

const buf2 = Buffer.from('7468697320697320612074c3a97374', 'hex');
// This tells that the first argument is encoded as a hexadecimal string

let str = buf2.toString();
// Gives back the readable english string
// which resolves to "this is a tést"

After you have data available in the readable format, you could store it using the fs module in NodeJS.

fs.writeFile('myFile.txt', "the contents of the file", (err) => {
  if(!err) console.log('Data written');
});

So, after converting the buffered input to string, you need to pass the string into the writeFile method. You could check the documentation of the fs module. It will help you better understand things.

edited Sep 15 '17 at 12:02

answered Sep 15 '17 at 10:28

Suhail Gupta

22,386
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thank you,but i don't understand how i can pass it to the fs so it can creates the file, basicly i know how the fs module works, but it is possible to pass the string and he creates the file? – costa costa Sep 15 '17 at 10:53
can you give me a short example? – costa costa Sep 15 '17 at 10:54
@costacosta Update with `writeFile` method. Please let me know if this helps. – Suhail Gupta Sep 15 '17 at 12:03
1

somehow it works, but the pdf file is empty you know why= – costa costa Sep 15 '17 at 13:09

usersina · Answer 2 · 2022-08-19T11:09:04.663

0

I had a function in a React app I wanted to test that expects a File so I had to improvise a little bit.

import { readFileSync } from 'fs';
import path from 'path';

const filePath = path.join(__dirname, 'some-file.csv');
const myFile = new File([readFileSync(file)], 'file.csv');

edited Aug 19 '22 at 11:09

answered Aug 19 '22 at 10:55

usersina

1,063
11
28

Create file based on buffer data in nodejs

2 Answers2