Weird bug about wildcard behavior in for statement

Weird bug about wildcard behavior in for statement

[Z C]

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I am currently using grub version 2.02 beta 2 got from git

In the grub command shell, if the first command I execute is

* for i in /*; do echo $i; done*

What I expect is the file/directory list of my $root partition. But the
result is just /* itself

Then if I execute the second command

*for i in /*; do echo $i; regexp '' $i; done*

I got the same result: /*

And if I execute the second command again, the result varies and I got the
file list as what I expected at the beginning.

Then if I execute the first command again, the result is still the file
list.

This test really shocked me, because the same command may produce different
result randomly. I really wonder what is the intended behavior of *
character in for statement

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Re: Weird bug about wildcard behavior in for statement

[Tobias Geerinckx]

On 31 May 2014 13:55, Z C <zcnnbb@gmail.com> wrote:
> I am currently using grub version 2.02 beta 2 got from git
>
> In the grub command shell, if the first command I execute is
>
> for i in /*; do echo $i; done
>
> What I expect is the file/directory list of my $root partition. But the
> result is just /* itself

Unless you've omitted an implied 'insmod regexp', this is correct.
The regexp module hasn't been loaded, so globbing is unavailable.

> Then if I execute the second command
>
> for i in /*; do echo $i; regexp '' $i; done
>
> I got the same result: /*
>
> And if I execute the second command again, the result varies and I got the
> file list as what I expected at the beginning.

Ah, but you've implicitly loaded the regexp module inside the loop.
Any subsequent commands will now behave as if

    grub> insmod regexp

was executed.

> Then if I execute the first command again, the result is still the file
> list.
>
> This test really shocked me, because the same command may produce different
> result randomly. I really wonder what is the intended behavior of *
> character in for statement

That depends on what you want it to do:
- If you want pattern matching, insert the regexp module.
- If you don't, remove it.

This is neither random nor a bug; it's GRUB doing exactly what you ask.


Regards,

Tobias (hoping Gmail doesn't suck as royally as it probably does)