code: func dumpConfig(ctx *cli.Context) error {
  	_, cfg := makeConfigNode(ctx)
  	comment := ""
  
  	if cfg.Eth.Genesis != nil {
  		cfg.Eth.Genesis = nil
  		comment += "# Note: this config doesn't contain the genesis block.\n\n"
  	}
  
  	out, err := tomlSettings.Marshal(&cfg)
  	if err != nil {
  		return err
  	}
  
  	dump := os.Stdout
  	if ctx.NArg() > 0 {
  		dump, err = os.OpenFile(ctx.Args().Get(0), os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
  		if err != nil {
  			return err
  		}
  		defer dump.Close()
  	}
  	dump.WriteString(comment)
  	dump.Write(out)
  
  	return nil
  }
docs: // dumpConfig is the dumpconfig command.