def exec(*commands)
      ret = ''
      commands.each { |cmd| ret += shell.exec(cmd) }
      ret + shell.exec('exec')
    end
def exec(*commands)
      ret = ''
      commands.each { |cmd| ret += shell.exec(cmd) }
      ret + shell.exec('exec')
    end
Creates the wrapper, executing the pfSense shell.

 The provided code block is yielded this wrapper for execution.

 Executes a series of commands on the pfSense shell.