# Compound File Binary Format
Pure JS implementation of MS-CFB: Compound File Binary File Format, a container
format used in many Microsoft file types (XLS, DOC, VBA blobs in XLSX and XLSB)
[](https://travis-ci.org/SheetJS/js-cfb)
[](https://coveralls.io/r/SheetJS/js-cfb?branch=master)
[](https://david-dm.org/sheetjs/js-cfb)
[](https://npmjs.org/package/cfb)
[](https://ghit.me/repo/sheetjs/js-xlsx)
[](https://github.com/SheetJS/js-cfb)
## Installation
In the browser:
```html
```
With [npm](https://www.npmjs.org/package/cfb):
```bash
$ npm install cfb
```
The `xlscfb.js` file is designed to be embedded in [js-xlsx](http://git.io/xlsx)
## Library Usage
In node:
```js
var CFB = require('cfb');
```
For example, to get the Workbook content from an Excel 2003 XLS file:
```js
var cfb = CFB.read(filename, {type: 'file'});
var workbook = CFB.find(cfb, 'Workbook');
var data = workbook.content;
```
## Command-Line Utility Usage
It is preferable to install the library globally with npm:
```bash
$ npm install -g cfb
```
The global installation adds a command `cfb` which can work with files:
- `cfb file [names...]` extracts the contents of the file. If additional names
are supplied, only the listed files will be extracted.
- `cfb -l file` lists the contained files (following `unzip -l` "short format")
- `cfb -r file` attempts to repair by reading and re-writing the file.
This fixes some issues with files generated by non-standard tools.
- `cfb -c file [files...]` creates a new file containing the listed files.
The default root entry name is `Root Entry`.
- `cfb -a file [files...]` adds the listed files to the original file.
- `cfb -d file [files...]` deletes the listed files from the original file.
## JS API
TypeScript definitions are maintained in `types/index.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, opts)` wraps `parse`. `opts.type` controls the behavior:
| `type` | expected input |
|------------|-----------------------------------------------------------------|
| `"base64"` | string: Base64 encoding of the file |
| `"binary"` | string: binary string (byte `n` is `data.charCodeAt(n)`) |
| `"file"` | string: path of file that will be read (nodejs only) |
| (default) | buffer or array of 8-bit unsigned int (byte `n` is `data[n]`) |
`CFB.find(cfb, path)` performs a case-insensitive match for the path (or file
name, if there are no slashes) and returns an entry object or null if not found.
`CFB.write(cfb, opts)` generates a file based on the container. `opts.type`
controls the behavior:
| `type` | output |
|------------|-----------------------------------------------------------------|
| `"base64"` | string: Base64 encoding of the file |
| `"binary"` | string: binary string (byte `n` is `data.charCodeAt(n)`) |
| `"file"` | string: path of file that will be created (nodejs only) |
| (default) | buffer if available, array of 8-bit unsigned int otherwise |
`CFB.writeFile(cfb, filename, opts)` creates a file with the specified name.
## Utility Functions
The utility functions are available in the `CFB.utils` object. Functions that
accept a `name` argument strictly deal with absolute file names:
- `.cfb_new(?opts)` creates a new container object.
- `.cfb_add(cfb, name, ?content, ?opts)` adds a new file to the `cfb`.
Set the option `{unsafe:true}` to skip existence checks (for bulk additions)
- `.cfb_del(cfb, name)` deletes the specified file
- `.cfb_mov(cfb, old_name, new_name)` moves the old file to new path and name
## Container Object Description
The objects returned by `parse` and `read` have the following properties:
- `.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)
- `.FileIndex` is an array, in the same order as `.FullPaths`, whose values are
objects following the schema:
```typescript
interface CFBEntry {
name: string; /** Case-sensitive internal name */
type: number; /** 1 = dir, 2 = file, 5 = root ; see [MS-CFB] 2.6.1 */
content: Buffer | number[] | Uint8Array; /** Raw Content */
ct?: Date; /** Creation Time */
mt?: Date; /** Modification Time */
}
```
## License
Please consult the attached LICENSE file for details. All rights not explicitly
granted by the Apache 2.0 License are reserved by the Original Author.
## References
OSP-covered Specifications (click to show)
- [MS-CFB]: Compound File Binary File Format