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Pure JS implementation of various container file formats, including ZIP and CFB.

In the browser:

<scriptsrc="dist/cfb.min.js"type="text/javascript"></script>

Withnpm:

$ npm install cfb

Thexlscfb.js file is designed to be embedded injs-xlsx

In node:

varCFB=require('cfb');

For example, to get the Workbook content from an Excel 2003 XLS file:

varcfb=CFB.read(filename,{type:'file'});varworkbook=CFB.find(cfb,'Workbook');vardata=workbook.content;

Thecfb-cli module ships with a CLItool for manipulating and inspecting supported files.

TypeScript definitions are maintained intypes/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 anparsed representation of the data.

CFB.read(blob, opts) wrapsparse.

CFB.find(cfb, path) performs a case-insensitive match for the path (or filename, 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:

CFB.write andCFB.writeFile take options argument.

opts.type controls the behavior:

opts.fileType controls the output file type:

opts.compression enables DEFLATE compression for ZIP file type.

The utility functions are available in theCFB.utils object. Functions thataccept aname 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. NodeJSzlib.InflateRaw exposes the number of bytes read in versions after8.11.0.If a suppliedzlib does not support the required features, a warning will bedisplayed in the console and the pure JS fallback will be used.

The objects returned byparse andread have the following properties:

• .FullPaths is an array of the names of all of the streams (files) andstorages (directories) in the container. The paths are properly prefixed fromthe root entry (so the entries are unique)

• .FileIndex is an array, in the same order as.FullPaths, whose values areobjects following the schema:

interfaceCFBEntry{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 explicitlygranted by the Apache 2.0 License are reserved by the Original Author.

• MS-CFB: Compound File Binary File Format
• ZIPAPPNOTE.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