Detect MIME type of uploaded file in Ruby

Question

Is there a bullet proof way to detect MIME type of uploaded file in Ruby or Ruby on Rails? I\'m uploading JPEGs and PNGs using SWFupload and content_type is alw

Answer 1

mimemagic gem will also do it

https://github.com/minad/mimemagic

from the oficial documentation

MimeMagic is a library to detect the mime type of a file by extension or by content. It uses the mime database provided by freedesktop.org (see http://freedesktop.org/wiki/Software/shared-mime-info/).

require 'mimemagic'
MimeMagic.by_extension('html').text?
MimeMagic.by_extension('.html').child_of? 'text/plain'
MimeMagic.by_path('filename.txt')
MimeMagic.by_magic(File.open('test.html'))
# etc...