    def self.open(path_or_url, ext = nil, options = {})
      options, ext = ext, nil if ext.is_a?(Hash)

      ext ||=
        if File.exist?(path_or_url)
          File.extname(path_or_url)
        else
          File.extname(URI(path_or_url).path)
        end

      ext.sub!(/:.*/, '') # hack for filenames or URLs that include a colon

      Kernel.open(path_or_url, "rb", options) do |file|
        read(file, ext)
      end
    end
The software constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.