leepa/istextorbinary

Determine if a filename and/or buffer is text or binary. Smarter detection than the other solutions.

Is Text or Binary?

Determine if a filename and/or buffer is text or binary. Smarter detection than the other solutions.

Determination works like so:

1. Extension Check: If filename is available, check if any of its extensions (from right to left) are an text extension or a binary extension, this is near instant.
2. Contents Check: If no filename was provided, or the extension check was indeterminate, then check the contents of the buffer.

The extension check will check each of the filename's extensions, from right to left. This is done as certain applications utilise multiple extensions for transformations, such as app.x.y may tell a compiler to transform from x format to y format, in this case perhaps x is not a recognized extension but y is, in which case we can make use of that to provide superior accuracy and convenience compared to just checking the rightmost extension.

The contents check (with the default options) will check 24 bytes at the start, middle, and end of the buffer. History has shown that checking all three locations is mandatory for accuracy, and that anything less is not accurate. This technique offers superior performance while still offering superior accuracy. Alternatives generally just do 1000 bytes at the start, which is slower, and inaccurate.

One cannot just do the contents check alone because UTF16 characters are indistinguishable from binary which would return an inaccurate result, hence why the combination is necessary for accuracy, with performance for known extensions a side-effect.

As such, this library's combination of extension check (if filename is provided), then contents check (if buffer is provided), offers superior performance and accuracy to alternatives.

Ever since 2012, this module's superior accuracy and performance has been essential to the operation of DocPad and its other dependents.

Usage

Complete API Documentation.

import { isText, isBinary, getEncoding } from 'istextorbinary'

or

const { isText, isBinary, getEncoding } = require('istextorbinary')

then

isText(aFilename) // returns true if a text file otherwise false, checks only filename
isText(null, aBuffer) // returns true if a text file otherwise false, checks only buffer
isText(aFilename, aBuffer) // returns true if a text file otherwise false, checks filename then buffer
isText(null, null) // returns null

isBinary(aFilename) // returns true if a binary file otherwise false, checks only filename
isBinary(null, aBuffer) // returns true if a binary file otherwise false, checks only buffer
isBinary(aFilename, aBuffer) // returns true if a binary file otherwise false, checks filename then buffer
isBinary(null, null) // returns null

getEncoding(aBuffer) // returns 'binary' if it contained non-utf8 characters, otherwise returns 'utf8'

Install

npm

• Install: npm install --save istextorbinary
• Import: import * as pkg from ('istextorbinary')
• Require: const pkg = require('istextorbinary')

Deno

import * as pkg from 'https://unpkg.com/istextorbinary@^5.12.0/edition-deno/index.ts'

Skypack

<script type="module">
    import * as pkg from '//cdn.skypack.dev/istextorbinary@^5.12.0'
</script>

unpkg

<script type="module">
    import * as pkg from '//unpkg.com/istextorbinary@^5.12.0'
</script>

jspm

<script type="module">
    import * as pkg from '//dev.jspm.io/[email protected]'
</script>

Editions

This package is published with the following editions:

• istextorbinary aliases istextorbinary/index.cjs which uses the Editions Autoloader to automatically select the correct edition for the consumer's environment
• istextorbinary/source/index.ts is TypeScript source code with Import for modules
• istextorbinary/edition-browsers/index.js is TypeScript compiled against ES2019 for web browsers with Import for modules
• istextorbinary/edition-esnext/index.js is TypeScript compiled against ESNext for Node.js 14 || 15 with Require for modules
• istextorbinary/edition-es2019/index.js is TypeScript compiled against ES2019 for Node.js 10 || 12 || 14 || 15 with Require for modules
• istextorbinary/edition-es2019-esm/index.js is TypeScript compiled against ES2019 for Node.js 12 || 14 || 15 with Import for modules
• istextorbinary/edition-deno/index.ts is TypeScript source code made to be compatible with Deno

History

Discover the release history by heading on over to the HISTORY.md file.

Contribute

Discover how you can contribute by heading on over to the CONTRIBUTING.md file.

Backers

Maintainers

These amazing people are maintaining this project:

• Benjamin Lupton — view contributions
• Michael Mooring — view contributions
• Rob Loach — view contributions

Sponsors

No sponsors yet! Will you be the first?

Contributors

These amazing people have contributed code to this project:

• Benjamin Lupton — view contributions
• Ian Sibner — view contributions
• Michael Mooring — view contributions
• Rob Loach — view contributions
• Sean — view contributions
• shinnn — view contributions

Discover how you can contribute by heading on over to the CONTRIBUTING.md file.

License

Unless stated otherwise all works are:

• Copyright © 2012+ Bevry Pty Ltd
• Copyright © 2011 Benjamin Lupton

and licensed under:

• MIT License