is-gzip-file

isGzipFile reads the first two bytes of a file to see if they match the magic number for gzip (1f 8b).

This is useful if you have a gzip task that shouldn't reprocess files, or if you have a web server that is server pre-gzipped files (without a .gz suffix).

Installation

npm install is-gzip

Usage

var isGzip('is-gzip');

var isGzipped = isGzip('./some-file') // returns true or false