# Compound File Binary Format 

This is a Pure-JS implementation of MS-CFB: Compound File Binary File Format, a
format used in many Microsoft file types (such as XLS, DOC, and other Microsoft
Office file types). 

# Utility Installation and Usage

The package is available on NPM:

```
$ npm install -g cfb
$ cfb path/to/CFB/file
```

The command will extract the storages and streams in the container, generating
files that line up with the tree-based structure of the storage.  Metadata 
such as the red-black tree are discarded (and in the future, new CFB containers
will exclusively use black nodes)

# Library Installation and Usage

In the browser:

    <script src="cfb.js" type="text/javascript"></script>

In node:

    var CFB = require('cfb');

For example, to get the Workbook content from an XLS file:

    var cfb = CFB.read(filename, {type: 'file'});
    var workbook = cfb.find('Workbook')

# API

Typescript definitions are maintained in `misc/cfb.d.ts`.

The CFB object exposes the following methods and properties:

`CFB.parse(blob)` takes a nodejs Buffer or an array of bytes and returns an
parsed representation of the data.

`CFB.read(blob, options)` wraps `parse`.  `options.type` controls the behavior:

- `file`: `blob` should be a file name
- `base64`: `blob` should be a base64 string
- `binary`: `blob` should be a binary string

## Container Object Description

The object returned by `parse` and `read` can be found in the source (`rval`).
It has the following properties and methods:

- `.find(path)` performs a case-insensitive match for the path (or file name, if
  there are no slashes) and returns an entry object (described later) or null if
  not found 

- `.FullPaths` is an array of the names of all of the streams (files) and 
  storages (directories) in the container.  The paths are properly prefixed from
  the root entry (so the entries are unique)

- `.FullPathDir` is an object whose keys are entries in `.FullPaths` and whose
  values are objects with metadata and content (described below)

- `.FileIndex` is an array of the objects from `.FullPathDir`, in the same order
  as `.FullPaths`.

- `.raw` contains the raw header and sectors 

## Entry Object Description

The entry objects are available from `FullPathDir` and `FileIndex` elements of the 
container object.

- `.name` is the (case sensitive) internal name
- `.type` is the type (`stream` for files, `storage` for dirs, `root` for root)
- `.content` is a Buffer/Array with the raw content
- `.ct`/`.mt` are the creation and modification time (if provided in file)

# Notes

Case comparison has not been verified for non-ASCII character

Writing is not supported.  It is in the works, but it has not yet been released.

# License

This implementation is covered under Apache 2.0 license.  It complies with the
[Open Specifications Promise](http://www.microsoft.com/openspecifications/)