etcdctl/ctlv3/command/get_command.go
func getCommandFunc(cmd *cobra.Command, args []string) {
	key, opts := getGetOp(args)
	ctx, cancel := commandCtx(cmd)
	resp, err := mustClientFromCmd(cmd).Get(ctx, key, opts...)
	cancel()
	if err != nil {
		ExitWithError(ExitError, err)
	}

	if printValueOnly {
		dp, simple := (display).(*simplePrinter)
		if !simple {
			ExitWithError(ExitBadArgs, fmt.Errorf("print-value-only is only for `--write-out=simple`"))
		}
		dp.valueOnly = true
	}
	display.Get(*resp)
}
func getCommandFunc(cmd *cobra.Command, args []string) {
	key, opts := getGetOp(args)
	ctx, cancel := commandCtx(cmd)
	resp, err := mustClientFromCmd(cmd).Get(ctx, key, opts...)
	cancel()
	if err != nil {
		ExitWithError(ExitError, err)
	}

	if printValueOnly {
		dp, simple := (display).(*simplePrinter)
		if !simple {
			ExitWithError(ExitBadArgs, fmt.Errorf("print-value-only is only for `--write-out=simple`"))
		}
		dp.valueOnly = true
	}
	display.Get(*resp)
}
// getCommandFunc executes the "get" command.