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The cfb npm package is a library designed for handling CFB (Compound File Binary) files, also known as Microsoft Compound Document File Format. This format is commonly used in older Microsoft Office documents like .doc, .xls, and .ppt files. The package allows for the creation, manipulation, and extraction of data from these files.
Reading CFB files
This code demonstrates how to read a CFB file from the filesystem. It uses the `read` method of the cfb package to load a file named 'test.xls' and logs the resulting data structure to the console.
const CFB = require('cfb');
const cfb = CFB.read('test.xls', {type: 'file'});
console.log(cfb);
Creating CFB files
This example shows how to create a new CFB file with a file named 'newfile.txt' inside it. It demonstrates creating a new CFB structure, adding a file to it, and then writing the CFB structure to a file named 'output.cfb'.
const CFB = require('cfb');
const cfb = CFB.utils.cfb_new();
CFB.utils.cfb_add(cfb, 'newfile.txt', new Uint8Array([1, 2, 3, 4, 5]));
CFB.write(cfb, 'output.cfb');
Extracting files from CFB containers
This snippet illustrates how to extract a file from a CFB container. It reads a CFB file named 'container.cfb', searches for a file named '/WordDocument' within the container, and logs its content.
const CFB = require('cfb');
const cfb = CFB.read('container.cfb', {type: 'file'});
const fileContent = CFB.find(cfb, '/WordDocument');
console.log(fileContent);
js-xlsx is a comprehensive library for parsing and writing spreadsheets in various formats including XLSX/XLSM/XLSB/XLS/ODS. It offers broader functionality for spreadsheet manipulation compared to cfb, which is focused on the CFB file format.
Pure JS implementation of various container file formats, including ZIP and CFB.
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
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;
The cfb-cli
module ships with a CLI
tool for manipulating and inspecting supported files.
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.
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] ) |
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.
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.use_zlib(require("zlib"))
loads a nodejs zlib
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.
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) */
}
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.
MS-CFB
: Compound File Binary File FormatAPPNOTE.TXT
: .ZIP File Format SpecificationFAQs
Compound File Binary File Format extractor
The npm package cfb receives a total of 2,265,638 weekly downloads. As such, cfb popularity was classified as popular.
We found that cfb demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 1 open source maintainer collaborating on the project.
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