unzip-stream

unzip-stream

Streaming cross-platform unzip tool written in node.js.

This package is based on unzip (and its fork unzipper) and provides simple APIs for parsing and extracting zip files. It uses new streaming engine which allows it to process also files which would fail with unzip. There are no added compiled dependencies - inflation is handled by node.js's built in zlib support.

Please note that the zip file format isn't really meant to be processed by streaming, though this library should succeed in most cases, if you do have complete zip file available, you should consider using other libraries which read zip files from the end - as originally intended (for example yauzl or decompress-zip).

Installation

$ npm install unzip-stream

Quick Examples

Parse zip file contents

Process each zip file entry or pipe entries to another stream.

Important: If you do not intend to consume an entry stream's raw data, call autodrain() to dispose of the entry's contents. Otherwise the stream will get stuck.

fs.createReadStream('path/to/archive.zip')
  .pipe(unzip.Parse())
  .on('entry', function (entry) {
    var filePath = entry.path;
    var type = entry.type; // 'Directory' or 'File'
    var size = entry.size; // might be undefined in some archives
    if (filePath === "this IS the file I'm looking for") {
      entry.pipe(fs.createWriteStream('output/path'));
    } else {
      entry.autodrain();
    }
  });

Parse zip by piping entries downstream

If you pipe from unzip-stream the downstream components will receive each entry for further processing. This allows for clean pipelines transforming zipfiles into unzipped data.

Example using stream.Transform:

fs.createReadStream('path/to/archive.zip')
  .pipe(unzip.Parse())
  .pipe(stream.Transform({
    objectMode: true,
    transform: function(entry,e,cb) {
      var filePath = entry.path;
      var type = entry.type; // 'Directory' or 'File'
      var size = entry.size;
      if (filePath === "this IS the file I'm looking for") {
        entry.pipe(fs.createWriteStream('output/path'))
          .on('finish',cb);
      } else {
        entry.autodrain();
        cb();
      }
    }
  }
  }));

Extract to a directory

fs.createReadStream('path/to/archive.zip').pipe(unzip.Extract({ path: 'output/path' }));

Extract will emit the 'close' event when the archive is fully extracted, do NOT use the 'finish' event, which can be emitted before the writing finishes.

Extra options

The Parse and Extract methods allow passing an object with decodeString property which will be used to decode non-utf8 file names in the archive. If not specified a fallback will be used.

let parser = unzip.Parse({ decodeString: (buffer) => { return iconvLite.decode(buffer, 'iso-8859-2'); } });
input.pipe(parser).pipe(...);

Change history

• 0.3.0 - Added full support for Zip64
• 0.2.3 - Fix compatibility with node4
• 0.2.2 - Better handling of unicode file names
• 0.2.0 - Make Extract() emit 'close' only once all files are written
• 0.1.2 - Deal with non-zip64 files larger than 4GB
• 0.1.0 - Implemented new streaming engine

What's missing?

Currently ZIP files up to version 4.5 are supported (which includes Zip64 support - archives with 4GB+ files). There's no support for encrypted (password protected) zips, or symlinks.