react-native-binary-file

A simple binary file reader for react-native. It uses RandomAccessFile and FileHandle.

Getting started

$npm i react-native-binary-file

Or

$ yarn add react-native-binary-file

Mostly automatic installation

React-Native < 0.60.x

$ react-native link react-native-binary-file

You can add and install use react-native install

$ react-native install react-native-binary-file

Create a briding header with:

//
//  Use this file to import your target's public headers that you would like to expose to Swift.
//

#import <React/RCTBridgeModule.h>

Manual installation

iOS

1. In XCode, in the project navigator, right click Libraries ➜ Add Files to [your project's name]
2. Go to node_modules ➜ react-native-binary-file and add RNBinaryFile.xcodeproj
3. In XCode, in the project navigator, select your project. Add libRNBinaryFile.a to your project's Build Phases ➜ Link Binary With Libraries
4. Run your project (Cmd+R)<

Android

1. Open up android/app/src/main/java/[...]/MainActivity.java

2. Add import com.reactlibrary.RNBinaryFilePackage; to the imports at the top of the file

3. Add new RNBinaryFilePackage() to the list returned by the getPackages() method

4. Setup gradle

Append the following lines to android/settings.gradle:

  include ':react-native-binary-file'
  project(':react-native-binary-file').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-binary-file/android')

Insert the following lines inside the dependencies block in android/app/build.gradle:

  compile project(':react-native-binary-file')

API

class BinaryFile {
  open(filename: string): Promise<number>;
  close(fd: number): Promise<void>;
  seek(fd: number, pos: number): Promise<void>;
  read(fd: number, len: number): Promise<Uint8Array>;
  readByte(fd: number): Promise<number>;
  readInt32(fd: number): Promise<number>;
  readInt64(fd: number): Promise<number>;
  readFloat32(fd: number): Promise<number>;
  readFloat64(fd: number): Promise<number>;
}

Usage

import { BinaryFile } from 'react-native-binary-file';

// Open a file for reading
const fd = await BinaryFile.open('path-to-file');

// Read a byte
const byteValue = await BinaryFile.readByte(fd);
// Read a next integer (int32) - big endian
const intValue = await BinaryFile.readInt32(fd);
// Read a next integer (int64) - big endian
const intValue = await BinaryFile.readInt64(fd);

// Seek to 1024
await BinaryFile.seek(fd, 1024);
// Read 512 bytes (uint8[])
const buffer = await BinaryFile.read(fd, 512);

// Close the file
await BinaryFile.close(fd);

// Another file
const fd2 = await BinaryFile.open('path-to-file-2');
// ...
await BinaryFile.close(fd2);