writeUInt64BE

Safely create 64 bit buffers or add them to an existing buffer

Writes number to buf at the specified offset with specified little endian format. Number should be a valid signed 64-bit integer.

In computing. The number 9,223,372,036,854,775,807, equivalent to the hexadecimal value 7FFF,FFFF,FFFF,FFFF16, is the maximum value for a 64-bit signed integer in computing.

value is interpreted and written as a two's complement signed integer.

writeInt32BE(buf, number[, offest])

• buf <Buffer> Original buffer to edit or change
• number <Integer> The signed integer to convert to a 64bit buffer
• offset <Integer> Where to start writing. Must satisfy: 0 <= offset <= buf.length - 8

Install

npm install writeuint64le

Usage

const Buffer = require('buffer').Buffer;
const writeUInt64LE = require('writeUInt64LE');

// First example, writing to a buffer at a specified location:

let buf = new Buffer(16);
buf.fill(0);

buf.writeUInt32LE(0x27101980, 4);
buf.writeUInt32LE(0x417, 0);
writeUInt64LE(buf, 123456789, 8);

console.log(buf); // <Buffer 17 04 00 00 80 19 10 27 15 cd 5b 07 00 00 00 00>

// Second example, concatenating to the original buffer:

let buf2 = new Buffer(8);
buf2.fill(0);

buf2.writeUInt32LE(0x27101980, 4);
buf2.writeUInt32LE(0x417, 0);
buf2 = writeUInt64LE(buf2, 123456789);

console.log(buf2); // <Buffer 17 04 00 00 80 19 10 27 15 cd 5b 07 00 00 00 00>