old_contents: from coalib.bearlib.abstractions.Linter import linter
  
  
  @linter(executable='shellcheck', output_format="regex",
          output_regex=r'.+:(?P<line>\d+):(?P<column>\d+): '
                       r'(?P<severity>error|warning|info): (?P<message>.+)')
  class ShellCheckBear:
      """
      Checks the given code with ``shellcheck``.
      """
  
      @staticmethod
      def create_arguments(filename, file, config_file, shell: str='sh'):
          """
          :param shell: Target shell being used.
          """
          return '--f', 'gcc', '-s', shell, filename
  
new_contents: from coalib.bearlib.abstractions.Linter import linter
  
  
  @linter(executable='shellcheck', output_format="regex",
          output_regex=r'.+:(?P<line>\d+):(?P<column>\d+): '
                       r'(?P<severity>error|warning|info): (?P<message>.+)')
  class ShellCheckBear:
      """
      Check bash/shell scripts for syntactical problems (with understandable
      messages), semantical problems as well as subtle caveats and pitfalls.
  
      A gallery of bad code that can be detected is available at
      <https://github.com/koalaman/shellcheck/blob/master/README.md>.
      """
  
      LANGUAGES = ("sh", "bash", "ksh", "dash")
  
      @staticmethod
      def create_arguments(filename, file, config_file, shell: str='sh'):
          """
          :param shell: Target shell being used.
          """
          return '--f', 'gcc', '-s', shell, filename
  
subject: Improve documentation