cfb
v1.2.2
Published
Compound File Binary File Format extractor
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Container File Blobs
Pure JS implementation of various container file formats, including ZIP and CFB.
Installation
In the browser:
<script src="dist/cfb.min.js" type="text/javascript"></script>
With npm:
$ npm install cfb
The xlscfb.js
file is designed to be embedded in js-xlsx
Library Usage
In node:
var CFB = require('cfb');
For example, to get the Workbook content from an Excel 2003 XLS file:
var cfb = CFB.read(filename, {type: 'file'});
var workbook = CFB.find(cfb, 'Workbook');
var data = workbook.content;
Command-Line Utility Usage
The cfb-cli
module ships with a CLI
tool for manipulating and inspecting supported files.
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
.
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.
CFB.writeFile(cfb, filename, opts)
creates a file with the specified name.
Parse Options
CFB.read
takes an options argument. 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)
) |
| "buffer"
| nodejs Buffer |
| "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]
) |
Write Options
CFB.write
and CFB.writeFile
take options argument.
opts.type
controls the behavior:
| type
| output |
|------------|:----------------------------------------------------------------|
| "base64"
| string: Base64 encoding of the file |
| "binary"
| string: binary string (byte n
is data.charCodeAt(n)
) |
| "buffer"
| nodejs Buffer |
| "file"
| string: path of file that will be created (nodejs only) |
| (default) | buffer if available, array of 8-bit unsigned int otherwise |
opts.fileType
controls the output file type:
| fileType
| output |
|:-------------------|:------------------------|
| 'cfb'
(default) | CFB container |
| 'zip'
| ZIP file |
| 'mad'
| MIME aggregate document |
opts.compression
enables DEFLATE compression for ZIP file type.
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 thecfb
. 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.use_zlib(require("zlib"))
loads a nodejszlib
instance.
By default, the library uses a pure JS inflate/deflate implementation. NodeJS
zlib.InflateRaw
exposes the number of bytes read in versions after 8.11.0
.
If a supplied zlib
does not support the required features, a warning will be
displayed in the console and the pure JS fallback will be used.
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:
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 */
ctype?: String; /** Content-Type (for MAD) */
}
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
MS-CFB
: Compound File Binary File Format- ZIP
APPNOTE.TXT
: .ZIP File Format Specification - RFC1951: https://www.ietf.org/rfc/rfc1951.txt
- RFC2045: https://www.ietf.org/rfc/rfc2045.txt
- RFC2557: https://www.ietf.org/rfc/rfc2557.txt