# File rbot/ircbot.rb, line 392
  def help(topic=nil)
    topic = nil if topic == ""
    case topic
      when nil
        helpstr = "rbot help topics: core, auth, keywords"
        helpstr += @plugins.helptopics
        helpstr += " (help <topic> for more info)"
      when /^core$/
        helpstr = corehelp
      when /^core\s+(.+)$/
        helpstr = corehelp $1
      when /^auth$/
        helpstr = @auth.help
      when /^auth\s+(.+)$/
        helpstr = @auth.help $1
      when /^keywords$/
        helpstr = @keywords.help
      when /^keywords\s+(.+)$/
        helpstr = @keywords.help $1
      else
        unless(helpstr = @plugins.help(topic))
          helpstr = "no help for topic #{topic}"
        end
    end
    return helpstr
  end