buffer-from

What is buffer-from?

The buffer-from npm package is a polyfill for the `Buffer.from` method that was added in Node.js v5.10.0. It allows users to create `Buffer` objects from various types of data such as strings, arrays, or other buffers. This package is particularly useful for environments that do not support the newer `Buffer.from` API.

What are buffer-from's main functionalities?

Creating a buffer from a string

This feature allows you to create a buffer from a string. The second argument specifies the string encoding.

const bufferFrom = require('buffer-from');
const buffer = bufferFrom('hello world', 'utf8');

Creating a buffer from an array

This feature allows you to create a buffer from an array of bytes.

const bufferFrom = require('buffer-from');
const buffer = bufferFrom([0x68, 0x65, 0x6c, 0x6c, 0x6f]);

Creating a buffer from another buffer

This feature allows you to create a new buffer from an existing buffer. The new buffer will be a copy of the original.

const bufferFrom = require('buffer-from');
const buffer1 = Buffer.alloc(10).fill('a');
const buffer2 = bufferFrom(buffer1);

Other packages similar to buffer-from

safe-buffer

The safe-buffer package provides a safer way of using Node.js buffers by ensuring compatibility with older versions of Node.js. It offers a similar API to buffer-from, but it also includes additional methods for buffer allocation and conversion.

buffer-alloc

The buffer-alloc package is specifically designed to create new buffer instances in a way that is safe across various Node.js versions. It is similar to buffer-from in that it provides a polyfill for buffer creation, but it focuses on allocation rather than conversion from other data types.

README

Buffer From

A ponyfill for Buffer.from, uses native implementation if available.

Installation

npm install --save buffer-from

Usage

const bufferFrom = require('buffer-from')

console.log(bufferFrom([1, 2, 3, 4]))
//=> <Buffer 01 02 03 04>

const arr = new Uint8Array([1, 2, 3, 4])
console.log(bufferFrom(arr.buffer, 1, 2))
//=> <Buffer 02 03>

console.log(bufferFrom('test', 'utf8'))
//=> <Buffer 74 65 73 74>

const buf = bufferFrom('test')
console.log(bufferFrom(buf))
//=> <Buffer 74 65 73 74>

API

bufferFrom(array)

• array <Array>

Allocates a new Buffer using an array of octets.

bufferFrom(arrayBuffer[, byteOffset[, length]])

• arrayBuffer <ArrayBuffer> The .buffer property of a TypedArray or ArrayBuffer
• byteOffset <Integer> Where to start copying from arrayBuffer. Default: 0
• length <Integer> How many bytes to copy from arrayBuffer. Default: arrayBuffer.length - byteOffset

When passed a reference to the .buffer property of a TypedArray instance, the newly created Buffer will share the same allocated memory as the TypedArray.

The optional byteOffset and length arguments specify a memory range within the arrayBuffer that will be shared by the Buffer.

bufferFrom(buffer)

• buffer <Buffer> An existing Buffer to copy data from

Copies the passed buffer data onto a new Buffer instance.

bufferFrom(string[, encoding])

• string <String> A string to encode.
• encoding <String> The encoding of string. Default: 'utf8'

Creates a new Buffer containing the given JavaScript string string. If provided, the encoding parameter identifies the character encoding of string.

See also

• buffer-alloc A ponyfill for Buffer.alloc
• buffer-alloc-unsafe A ponyfill for Buffer.allocUnsafe