class ImageOptimizer
  module Shell
    # most of the code from MiniMagick, they didn't write any tests

    def self.included(base)
      base.extend ClassMethods
    end

    def which(cmd)
      self.class.which(cmd)
    end

    def run_command(command)
      self.class.run_command(command)
    end

    module ClassMethods
      # Cross-platform way of finding an executable in the $PATH.
      def which(cmd)
        exts = ENV['PATHEXT'] ? ENV['PATHEXT'].split(';') : ['']
        ENV['PATH'].split(File::PATH_SEPARATOR).each do |path|
          exts.each do |ext|
            exe = File.join(path, "#{cmd}#{ext}")
            return exe if File.executable? exe
          end
        end
        nil
      end

      def run_command(command)
        `#{command}`
      end
    end

  end
end