[removed] reading 3 bytes Buffer as an integer

Question

Let\'s say I have a hex data stream, which I want to divide into 3-bytes blocks which I need to read as an integer.

For example: given a hex string 01be638119704d4

Answer 1

I'm using this, if someone knows something wrong with it, please advise;

const integer = parseInt(buffer.toString("hex"), 16)

Answer 2

you should convert three byte to four byte.

function three(var sample){
    var buffer = new Buffer(sample, 'hex');

    var buf = new Buffer(1);
    buf[0] = 0x0;

    return Buffer.concat([buf, buffer.slice(0, 3)]).readUInt32BE();
}

You can try this function.

Answer 3

If you are using node.js v0.12+ or io.js, there is buffer.readUIntBE() which allows a variable number of bytes:

var decimal = buffer.readUIntBE(0, 3);

(Note that it's readUIntBE for Big Endian and readUIntLE for Little Endian).

Otherwise if you're on an older version of node, you will have to do it manually (check bounds first of course):

var decimal = (buffer[0] << 16) + (buffer[1] << 8) + buffer[2];