GRF Loader

GRF is an archive file format that support lossless data compression used on Ragnarok Online to store game assets. A GRF file may contain one or more files or directories that may have been compressed (deflate) and encrypted (variant of DES).

About

• Only supports GRF version 0x200.
• It's working both on node and browser environments
• Supports DES description.
• Avoid bloating client/server memory (by not loading the whole file into the RAM)
• Does not supports custom encryption

Installation

npm install grf-loader

Basic usage

• Load a grf file on node.js
• Load a grf from the browser
• List all files content
• Extract a file from the GRF

Load a grf file on node.js

import {GrfNode} from 'grf-loader';
import {openSync} from 'path';
 
const fd = openSync('path/to/data.grf', 'r');
const grf = new GrfNode(fd);
 
// Start parsing the grf.
await grf.load();

Load a grf from the browser

import {GrfBrowser} from 'grf-loader';
 
const blob = document.querySelector('input[type="file"]').files[0];
const grf = new GrfBrowser(blob);
 
// Start parsing the grf
await grf.load();

List all files content

Once the GRF is loaded, it's possible to list all files included inside it

grf.files.forEach((entry, path) => {
  console.log(path);
});

Extract a file from the GRF

Once the GRF is loaded, it's possible to extract all files you need

const {data, error} = await grf.getFile('data\\clientinfo.xml');
 
// data is a Uint8Array data, so we transform it into text
const content = String.fromCharCode.apply(null, data);
console.log(content);