Buffer to base64 | Node.js

Question

I have a buffer which is being populated with a bunch of base64 strings. I want a way to decode those string and be able to read all of the base64 strings in that buffer.

const slugId1 = 'YriU6QbcQj6xtdUUosJTxA==';
const slugId2 = 'Su7Zvq1vRca/teTNfEmfNQ==';
const SLUGID_SIZE = 16;

let buffer = Buffer.alloc(SLUGID_SIZE * 2);

buffer.write(slugId1, 0, SLUGID_SIZE, 'base64');
buffer.write(slugId2, SLUGID_SIZE, SLUGID_SIZE, 'base64');

console.log(buffer.toString('base64', 0, SLUGID_SIZE));
console.log(buffer.toString('base64', SLUGID_SIZE, SLUGID_SIZE));

What I'm getting:

YriU6QbcQj6xtdUUosJTxA==

What I expect to get:

YriU6QbcQj6xtdUUosJTxA==
Su7Zvq1vRca/teTNfEmfNQ==

Any help is appreciated.

buffer.toString 2nd and 3rd parameter are start and end - given you give the same value for start and end, the result is of course zero length — Jaromanda X
– Jaromanda X, Commented Aug 30, 2017 at 4:14

kangsu · Accepted Answer · 2017-08-30 04:19:03Z

3

try this

const slugId1 = 'YriU6QbcQj6xtdUUosJTxA==';
const slugId2 = 'Su7Zvq1vRca/teTNfEmfNQ==';
const SLUGID_SIZE = 16;

let buffer = Buffer.alloc(SLUGID_SIZE * 2);

buffer.write(slugId1, 0, SLUGID_SIZE, 'base64');
buffer.write(slugId2, SLUGID_SIZE, SLUGID_SIZE, 'base64');

console.log(buffer.toString('base64', 0, SLUGID_SIZE));
console.log(buffer.toString('base64', SLUGID_SIZE, SLUGID_SIZE * 2));

buffer.toString() - third argument is not length, it is end offset.

edited Aug 30, 2017 at 4:19

answered Aug 30, 2017 at 4:12

kangsu

2261 silver badge6 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Jaromanda X Over a year ago

buffer.write() - third argument is not length, it is end offset - no, for write it is a length - see documentation - you could actually do buffer.write(slugId2, SLUGID_SIZE, 'base64'); - because the length defaults to buffer.length - offset - in this case, it would be SLUGID_SIZE

helfi Over a year ago

Yup, that did it. Thanks for the quick response!

Collectives™ on Stack Overflow

Buffer to base64 | Node.js

1 Answer 1

2 Comments

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Related