How to read a section of a large file with Node.js?

Question

I have a very large, binary file (>25 GB), and I need to very quickly read a small range of bytes from it at a specific offset. How can I accomplish this in Node.js in an efficient way?

Answer 1

A fairly minimal example of what you want, refer to https://nodejs.org/api/all.html#fs_fs_createreadstream_path_options for more details

const fs = require("fs");

const stream = fs.createReadStream("test.txt", { start: 1, end: 5 });

stream.on("data", chunk => console.log(chunk.toString()));

Provided you have a file called test.txt of course...