Detect the file type of a Buffer/Uint8Array
The file type is detected by checking the [magic number](http://en.wikipedia.org/wiki/Magic_number_(programming)#Magic_numbers_in_files) of the buffer.
$ npm install file-type
const readChunk = require('read-chunk');
const fileType = require('file-type');
const buffer = readChunk.sync('unicorn.png', 0, 4100);
fileType(buffer);
//=> {ext: 'png', mime: 'image/png'}
Or from a remote location:
const http = require('http');
const fileType = require('file-type');
const url = 'http://assets-cdn.github.com/images/spinners/octocat-spinner-32.gif';
http.get(url, res => {
res.once('data', chunk => {
res.destroy();
console.log(fileType(chunk));
//=> {ext: 'gif', mime: 'image/gif'}
});
});
const xhr = new XMLHttpRequest();
xhr.open('GET', 'unicorn.png');
xhr.responseType = 'arraybuffer';
xhr.onload = () => {
fileType(new Uint8Array(this.response));
//=> {ext: 'png', mime: 'image/png'}
};
xhr.send();
Returns an Object with:
ext - One of the supported file typesmime - The MIME typeOr null when no match.
Type: Buffer Uint8Array
It only needs the first 4100 bytes. The exception is detection of docx, pptx, and xlsx which potentially requires reading the whole file.
jpgpnggifwebpflifcr2tifbmpjxrpsdzip](https://en.wikipedia.org/wiki/Zip_(file_format))tar](https://en.wikipedia.org/wiki/Tar_(computing)#File_format)rar](https://en.wikipedia.org/wiki/RAR_(file_format))gzbz27zdmgmp4m4vmidmkvwebmmovaviwmvmpgmp2mp3m4aoggopus](https://en.wikipedia.org/wiki/Opus_(audio_format))flacwavqcpamrpdfepubmobi - Mobipocketexeswfrtfwoffwoff2eotttfotfico](https://en.wikipedia.org/wiki/ICO_(file_format))flvpsxzsqlitenescrxxpicab](https://en.wikipedia.org/wiki/Cabinet_(file_format))deb](https://en.wikipedia.org/wiki/Deb_(file_format))ar](https://en.wikipedia.org/wiki/Ar_(Unix))rpmZlzmsimxfmtswasmblendbpgdocxpptxxlsx3gpjp2 - JPEG 2000jpm - JPEG 2000jpx - JPEG 2000mj2 - Motion JPEG 2000aifodt - OpenDocument for word processingods - OpenDocument for spreadsheetsodp - OpenDocument for presentationsxmlheiccur](https://en.wikipedia.org/wiki/ICO_(file_format))ktxape - Monkey's Audiowv - WavPackSVG isn't included as it requires the whole file to be read, but you can get it here.
Pull request welcome for additional commonly used file types.
MIT