autodetecting MBR location

[Russell Coker <russell@coker.com.au>]

My lilo configuration scripts need to be able to infer the correct location 
for the MBR.  I am currently using the following algorithm:
take root fs device from /etc/fstab and do the following:
s/[0-9]*//
s/part$/disc/

The latter is for devfs.

Now for the benefit of RAID systems I need to do:
if($device =~ /\/dev\/md/)
{
  my $mdname = $device;
  $mdname =~ s/\/dev\///;
  $mdname =~ s/\///;
  my $md = `grep $mdname /proc/mdstat`;
  my @devices = split(" ", $md);
  @devices = sort(@devices[4..$#devices]);
  $root = "/dev/" . $devices[0];
  $root =~ s/\[.*$//;
}

Before the part of:
s/[0-9]*//
s/part$/disc/

The debconf code that Gergely Risko <risko@atom.hu> wrote is what I'm 
building on.  Gergely's code has essentially s/[0-9]*// inlined which is ok 
for a non-RAID non-devfs system.  But I want to work with all combinations of 
RAID and non-RAID, devfs and non-devfs and also expand to LVM in the near 
future.  So I can't do that.  I currently plan to put a program to do this 
under /usr/sbin.

Now I have the following questions:
1)  Does anyone have any similar code for doing this that I can merge my code 
with?
2)  Does anyone else need the same code?  If so please tell me what you need 
and I'll make my code as generic as I can.
3)  Can anyone see any obvious bugs in the above?

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