Determine file type in Ruby

Question

How does one reliably determine a file\'s type? File extension analysis is not acceptable. There must be a rubyesque tool similar to the UNIX file(1) comman

Answer 1

For those who came here by the search engine, a modern approach to find the MimeType in pure ruby is to use the mimemagic gem.

require 'mimemagic'

MimeMagic.by_magic(File.open('tux.jpg')).type # => "image/jpeg" 

If you feel that is safe to use only the file extension, then you can use the mime-types gem:

MIME::Types.type_for('tux.jpg') => [#]