unzip-js

unzip .ZIP files in the browser

Install

npm install unzip-js

Usage

var unzip = require('unzip-js')

unzip(getBlobOrFileSomehow(), function (err, zipFile) {
  if (err) {
    return console.error(err)
  }

  zipFile.readEntries(function (err, entries) {
    if (err) {
      return console.error(err)
    }

    entries.forEach(function (entry) {
      zipFile.readEntryData(entry, false, function (err, readStream) {
        if (err) {
          return console.error(err)
        }

        readStream.on('data', function (chunk) { ... })
        readStream.on('error', function (err) { ... })
        readStream.on('end', function () { ... })
      })
    })
  })
})

API

unzip(source, callback)

• source: must be a Blob, File or string that represents a valid url.
• callback: function(err: Error, zipFile: ZipFile)

Class: ZipFile

zipFile.readEntries(callback)
Read metadata of all entries (parse Central Dircotroy Records).

• callback: function(err: Error, entries: Entry[])

zipFile.readEntryData(entry, checkCrc, callback)
Read data of a specific entry.

• entry: Entry
• callback: function(err: Error, readStream: ReadStream)
• checkCrc: boolean if true, performs a crc32 check on the extracted data.

Class: Entry
A representation of a zip entry (a Central Dircotroy Record).

see the zip spec section 4.3.12 Central directory structure for more informations.

entry.versionMadeBy: number
entry.versionNeededToExtract: number
entry.generalPurposeBitFlag: number
entry.compressionMethod: number
entry.lastModTime: number
entry.lastModDate: number
entry.crc32: number
entry.compressedSize: number
entry.uncompressedSize: number
entry.internalAttributes: number
entry.externalAttributes: number
entry.localHeaderOffset: number
entry.name: string
entry.commment: string
entry.extraFields: object[]

• object: { headerId: number, dataSize: number, data: Buffer }

entry.encrypted: boolean
retrun true if the data is encrypted.

entry.lastModTimeDate: Date
Return a Date object representation of entry.lastModTime and entry.lastModDate.

Class: ReadStream
see blob-slicer.

Limitations

Only files stored with no compression or compressed with deflate algorithm are supported, zipFile.readEntryData callback will recieve an error for any entry with compression methode other than 0 (stored) or 8 (deflated), or if the file is encrypted.

Zip files spanned across multiple removable media are not supported.

Supported browsers

Firefox	Chrome	Internet Explorer	Edge	Safari	ios	Android
YES	YES	YES (10 - 11)	YES	YES	YES	YES

License

MIT. Copyright (c) Merzouqi.