module Sinatra::Helpers

def send_file(path, opts={})
  stat = File.stat(path)
  last_modified stat.mtime
  content_type mime_type(opts[:type]) ||
    mime_type(File.extname(path)) ||
    response['Content-Type'] ||
    'application/octet-stream'
  response['Content-Length'] ||= (opts[:length] || stat.size).to_s
  if opts[:disposition] == 'attachment' || opts[:filename]
    attachment opts[:filename] || path
  elsif opts[:disposition] == 'inline'
    response['Content-Disposition'] = 'inline'
  end
  halt StaticFile.open(path, 'rb')
rescue Errno::ENOENT
  not_found
end