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Deno standard library
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class Untar
import { Untar } from "";


A class to extract from a tar archive. Tar archives allow for storing multiple files in a single file (called an archive, or sometimes a tarball). These archives typically have the '.tar' extension.

Supported file formats

Only the ustar file format is supported. This is the most common format. The pax file format may also be read, but additional features, such as longer filenames may be ignored.


The workflow is to create a Untar instance referencing the source of the tar file. You can then use the untar reference to extract files one at a time. See the worked example below for details.

Understanding compression

A tar archive may be compressed, often identified by the .tar.gz extension. This utility does not support decompression which must be done before extracting the files.


Example 1

import { Untar } from "";
import { ensureFile } from "";
import { ensureDir } from "";
import { copy } from "";

using reader = await"./out.tar", { read: true });
const untar = new Untar(reader);

for await (const entry of untar) {
  console.log(entry); // metadata

  if (entry.type === "directory") {
    await ensureDir(entry.fileName);

  await ensureFile(entry.fileName);
  using file = await, { write: true });
  // <entry> is a reader.
  await copy(entry, file);


Untar(reader: Reader)


block: Uint8Array
reader: Reader


extract(): Promise<TarEntry | null>

Extract the next entry of the tar archive.

[Symbol.asyncIterator](): AsyncIterableIterator<TarEntry>

Iterate over all entries of the tar archive.