Re: [PATCH] Save/Load environment variable support

[Bean]

On Fri, Jul 4, 2008 at 2:09 AM, Pavel Roskin <address@hidden> wrote:
> On Thu, 2008-07-03 at 20:04 +0200, Marco Gerards wrote:
>
>> Great!  Can you explain how it works?
>
> Very good question.  It's not "discoverable".  I could not find way to
> figure out that /boot/grub/grubenv is the default without looking at the
> code.
>
> load_env without arguments merely prints "error: file not found" without
> telling which file it needs.  Help texts are silent about the defaults.
> Many commands ignore extra arguments silently.  The whole code needs a
> serious cleanup with end users in mind.

load_env would load /boot/grub/grubenv with no input, you can also
overwrite the default with -f parameter.

BTW, I think update-grub should create a new grubenv if it doesn't
exists, so that user won't see the file not found error.

>
> We also have too many commands regarding environment.  There is even
> freebsd_loadenv, which should probably merged with load_env somehow.  Or
> maybe not.  Maybe all native environment files should be handled with
> one command, such as "env".

freebsd_loadenv is used to load the hint file, which is plain text. It
also add the FreeBSD prefix so that they won't conflict with native
variables of grub2.

>
> We also need mechanisms to implement "savedefault" functionality,
> perhaps with easy examples.  Maybe update-grub should use it.
>
> Anyway, to start using it, create the environment file: grub-editenv (by
> the way, grub-env would be a better name):
>
> grub-editenv /boot/grub/grubenv create
> grub-editenv /boot/grub/grubenv set foo=bar
>
> Now you can inspect it with "list_env", load it into environment with
> "load_env" and save variables into it with "save_env".

Yes, this is the basic idea.

-- 
Bean