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From: Marco Gerards <mgerards@xs4all.nl>
To: The development of GRUB 2 <grub-devel@gnu.org>
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Date: Wed, 13 Aug 2008 12:31:21 +0200
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	(bean123ch@gmail.com's message of "Tue, 12 Aug 2008 05:03:10 +0800")
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Subject: Re: Idea: use menu hook to implement the savedefault command
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Bean <bean123ch@gmail.com> writes:

> Hi,
>
> Now it's possible to implement savedefault with load_env and save_env,
> but the problem is we need to add it to every menuitem, it's tedious
> process, and new item don't get it automatically.
>
> I'm thinking about using menu hook to solve this. I can think of two
> implementation:
>
> 1. Function interface
>
> We can install hooks, which get called just before the menu is invoked.
>
> 2. Script interface
>
> We can use certain variable to specific the command to use, for example:
>
> set MENU_PRELOAD=save_env default

Wouldn't this be a BOOT_PRELOAD?

I thought about this before (see archives about scripting), making it
possible for the user to add hooks.

In C:

... menu code ...
/* The `menu' hook has one argument.  */
grub_hook_invoke ("menu", 1, arglist);


In scripting:

function menu_hook_handler()
  save_env;

hook --register --hook=menu --script menu_hook_handler

Or do you think I am crazy now? ;-)

This will involve some scripting hacking, but might pay off.  Do you
think this is too complex for users?