How to untar file in node.js - node.js

Question

There are some untar libraries, but I cannot get them working.
My idea would be something like
untar(bufferStreamOrFilePath).extractToDirectory("/path", function(err){})
Is something like this available?

Answer 1

Just an update on this answer, instead of node-tar, consider using tar-fs which yields a significant performance boost, as well as a neater interface.
var tarFile = 'my-other-tarball.tar';
var target = './my-other-directory';
// extracting a directory
fs.createReadStream(tarFile).pipe(tar.extract(target));

Answer 2

The tar-stream module is a pretty good one:
var tar = require('tar-stream')
var fs = require('fs')
var extract = tar.extract();
extract.on('entry', function(header, stream, callback) {
// make directories or files depending on the header here...
// call callback() when you're done with this entry
});
fs.createReadStream("something.tar").pipe(extract)
extract.on('finish', function() {
console.log('done!')
});

Answer 3

A function to extract a base64 encoded tar fully in memory, with the assumption that all the files in the tar are utf-8 encoded text files.
const tar=require('tar');
let Duplex = require('stream').Duplex;
function bufferToStream(buffer) {
let stream = new Duplex();
stream.push(buffer);
stream.push(null);
return stream;
}
module.exports=function(base64EncodedTar){
return new Promise(function(resolve, reject){
const buffer = new Buffer.from(base64EncodedTar, "base64");
let files={};
try{
bufferToStream(buffer).pipe(new tar.Parse())
.on('entry', entry => {
let file={
path:entry.path,
content:""
};
files[entry.path]=file;
entry.on('data', function (tarFileData) {
file.content += tarFileData.toString('utf-8');
});
// resolve(entry);
}).on('close', function(){
resolve(files);
});
} catch(e){
reject(e);
}
})
};

Answer 4

Expanding on the tar-stream answer, that seemed to be the simplest to use in the browser with jest-tested code. Comparing the node libraries based on my trying to implement a project:
tar: Fairly easy to use on files, or buffers as in or Gudlaugur Egilsson's answer. It had some annoying webpack polyfill issues that I had trouble with when putting it into a react app.
js-untar: This was pretty annoying to set up for jest testing because it uses web workers and blob URLs, which jest does not directly support. I didn't proceed to getting it working in the browser, though it may work fine there. In order to get jest tests working, I had to use jsdom-worker-fix, and it was very slow in that environment. (It may be faster in-browser.)
tar-stream combined with gunzip-maybe seems to be fairly performant in browser, and doesn't have any issues with being used in jest tests. Worked fine on multi-hundred megabyte tarballs I tried.
This code extracts a tar or tar.gz stream:
var tar = require("tar-stream");
const gunzip = require("gunzip-maybe");
exports.unTar = (tarballStream) => {
const results = {};
return new Promise((resolve, reject) => {
var extract = tar.extract();
extract.on("entry", async function (header, stream, next) {
const chunks = [];
for await (let chunk of stream) {
chunks.push(chunk);
}
results[header.name] = Buffer.concat(chunks);
next();
});
extract.on("finish", function () {
resolve(results);
});
tarballStream.pipe(gunzip()).pipe(extract);
});
};
Then in browser, you can use readable-web-to-node-stream to process a tarball fetched in the browser.
const { ReadableWebToNodeStream } = require("readable-web-to-node-stream");
const response = await fetch(url, headers);
const extracted = await unTar(new ReadableWebToNodeStream(response.body));