code: def do_open(self, args, arguments):
          
          filename = arguments['FILENAME']
          filename = self._expand_filename(filename)
          Console.ok("open {0}".format(filename))
  
          if not (filename.startswith("file:") or filename.startswith("http:")):
              try:
                  with open(filename):
                      pass
                  filename += "file://"
              except:
                  Console.error("unsupported browser format in file {0}".format(filename))
                  return
  
          try:
              webbrowser.open("%s" % filename)
          except:
              Console.error("can not open browser with file {0}".format(filename))
docs: ::
  
              Usage:
                      open FILENAME
  
              ARGUMENTS:
                  FILENAME  the file to open in the cwd if . is
                            specified. If file in in cwd
                            you must specify it with ./FILENAME
  
              Opens the given URL in a browser window.