Detect the file type of a Buffer/Uint8Array
The file type is detected by checking the magic number of the buffer.
Install
$ npm install --save file-type
Usage
Node.js
var readChunk = require('read-chunk'); // npm install read-chunk
var fileType = require('file-type');
var buffer = readChunk.sync('unicorn.png', 0, 262);
fileType(buffer);
//=> {ext: 'png', mime: 'image/png'}
or from a remote location:
var http = require('http');
var fileType = require('file-type');
var url = 'http://assets-cdn.github.com/images/spinners/octocat-spinner-32.gif';
http.get(url, function (res) {
res.once('data', function (chunk) {
res.destroy();
console.log(fileType(chunk));
//=> {ext: 'gif', mime: 'image/gif'}
});
});
Browser
var xhr = new XMLHttpRequest();
xhr.open('GET', 'unicorn.png');
xhr.responseType = 'arraybuffer';
xhr.onload = function () {
fileType(new Uint8Array(this.response));
//=> {ext: 'png', mime: 'image/png'}
};
xhr.send();
API
fileType(buffer)
Returns an object (or null
when no match) with:
ext
- one of the supported file typesmime
- the MIME type
buffer
Type: buffer
(Node.js), uint8array
It only needs the first 262 bytes.
CLI
$ npm install --global file-type
$ file-type --help
Usage
file-type <filename>
cat <filename> | file-type
Example
cat unicorn.png | file-type
png
Supported file types
jpg
png
gif
webp
tif
bmp
jxr
psd
zip
tar
rar
gz
bz2
7z
mp4
mkv
webm
mov
avi
wmv
mpg
mp3
m4a
ogg
flac
wav
pdf
epub
exe
swf
rtf
woff
woff2
eot
SVG isn't included as it requires the whole file to be read, but you can get it here.
PR welcome for additional commonly used file types.
License
MIT © Sindre Sorhus