Ruby on Rails: How do you check if a file is an image?

Question

How would you check if a file is an image? I\'m thinking you could use an method like so:

def image?(file)
  file.to_s.include?(\".gif\") or file.to_s.includ         


        

Answer 1

As an addition to Joel's answer, in Rails 5 I had to transform the comparison string to a bytecode. Eg:

def jpeg?(data)
  return data[0,4]=="\xff\xd8\xff\xe0".b
end