node-nthline

nthline reads specific line from file without buffering the entire file to memory. Under the hood it uses Node’s readline module.

Install

npm i -S nthline

Usage

Module exposes just one function: nthline with signature: (rowNumber:Number, filePath:String) → Promise.

(async () => {
  const nthline = require('nthline')
    , filePath = '/path/to/100-million-rows-file'
    , rowNumber = 42

  console.log(await nthline(rowNumber, filePath))
})()

Since it returns a promise you could rewrite previous example like that:

const nthline = require('nthline')
    , filePath = '/path/to/100-million-rows-file'
  , rowNumber = 42

nthline(rowNumber, filePath)
  .then(line => console.log(line))