nodeunrar

nodeunrar is a npm module to extract rar archive in pure JavaScript. It's combined by a Javascript adoption layer and JavaScript unRar library compiled by Emscripten from the C++ unrar library from http://www.rarlab.com/rar_add.htm .

Installation

You can install the module via npm:

npm install @huanjiesm/nodeunrar

Features

• Fully support for RAR archive, because it comes from the official source code.
• Unicode support, for both comment and file path/name.
• API for Extraction to both memory and file system.

Unsupported Features

• Volume archives are not supported.
• Synchronize File System IO functions are used in File Extraction for the limitation of the library.
• Files must be extracted at once now, can not be extracted one by one for progress indicator (may be improved later).

API to create the extractor

• createExtractorFromData(data: ArrayBuffer, password?: string) - Create the Memory Extractor

  Options:

  • data : ArrayBuffer object of the RAR archive file.
  • password : Optional string for extraction password

• createExtractorFromFile(filepath: string, targetPath?: string, password?: string) - Get the File Extractor

  Options:

  • filepath : File path of the RAR archive file.
  • targetPath : Optional string target folder
  • password : Optional string for extraction password

API of the extractor

• getFileList() : Get the file list of the archive. Return: [state, result]
  • If function call failed
    • the state will be {state: "FAIL", reason: <FailReason>, msg: <string>}
    • the result will be null.
  • When function call success
    • the state will be {state: "SUCCESS"}
    • the result will be like:

{
  arcHeader: {
    comment: "",
    flags: {
      authInfo: false,
      headerEncrypted: false,
      lock: false,
      recoveryRecord: false,
      solid: false,
      volume: false,
    },
  }, fileHeaders: [
    {
      crc: 0,
      flags: {
        directory: false,
        encrypted: false,
        solid: false,
      },
      method: "Storing", 
      name: "FileName",
      packSize: 0,
      time: "2017-04-03T10:41:42.000",
      unpSize: 0,
      unpVer: "2.9", 
    },
    // ...
  ]
}

• extractAll(): Extract all the files.

  Return: [state, result]

  • If function call failed, the response will be structed like return value above.
  • When function call success
    • the result will be like:

{
  arcHeader: {...} // Same as the arcHeader above
  files: [
    {
      fileHeader: {...} // Same as the fileHeader above
      extract: [state, extractedContent]
  ]
}

The state above will be same as the state of the return above, and the extractedContent will be null if file extract failed or in File extraction mode.

If extracted successful, the extractedContent will be Uint8Array object.

• extractFiles(files: string[], password?: string): Extract the specific files

  Option:

  • files: File path list to be extracted.
  • password: A different to main password may be set on these specific files.

  Return:

  Same to the return value of extractAll(), the result will be stored in the same order of the input array files. If the specific file is not found in the archive, the file item of the files array will be null.

Example

var fs = require("fs");
var unrar = require("node-unrar-js");

// Read the archive file into a typedArray
var buf = Uint8Array.from(fs.readFileSync("a.rar")).buffer;
var extractor = unrar.createExtractorFromData(buf);

var list = extractor.getFileList();
if (list[0].state === "SUCCESS") {
  list[1].arcHeader...
  list[1].fileHeaders[...]
}

var extracted = extractor.extractAll();
var extracted = extractor.extractFiles(["1.txt", "1.txt"], "password")();
if (list[0].state === "SUCCESS") {
  list[1].arcHeader...
  list[1].files[0].fileHeader: ..
  if (list[1].files[0].extract[0].state === "SUCCESS") {
    list[1].files[0].extract[1] // Uint8Array 
  }
}

TypeScript

This module is written in TypeScript, you can import it directly in TypeScript and get the benefit of static type checking and auto-complete of IDE.

Development and Contribution

If you want to compile the module by yourself, please follow the steps below:

• Pull the docker image for Emscripten (Please install the docker at first)

docker pull apiaryio/emcc

• Download the c++ source of unRar library:

npm run prepare

• Build for debug:

npm run buildDebug

• Build for release

npm run buildRelease

• Run Test

npm run test

License

This module is licensed under MIT.

Changelog

0.8.0:

• First release