Commands.pm / @preserved_raid

[Kerim Gueney]

Hey, I had totally forgotten this; sorry about that.

Yeah, your code is nice, but I really want something small instead of 
what is basically an entire script(-file). Then again I don't really 
want to be the person to decide this, so perhaps you could prepare a git 
patch and just let Thomas know and he'll see.

Good night
Kerim

On 29/08/14 14:28, Thomas Neumann wrote:
> Hello Kerim
>
> Can you please explain the following line from Commands.pm?
>    my $tmp_vg = `pvdisplay $raid | grep "VG Name" | grep -o "vg[0-9]"`;
>
> Does this really mean you only consider volume groups with a name of
> 'vg<digit>....' as valid values for $tmp_vg?
>
>
> This is how I would do it. Maybe there is something I'm missing.
>
> #!/usr/bin/perl
>
> use strict;
> use warnings;
>
> my $raid = shift;
>
> # ------------------- the code -------------------------
> # fetch the pvdisplay output
> my @output = `pvdisplay $raid`;
> chomp @output;
>
> # iterate output, looking for volume group name
> my $tmp_vg;
> for my $line (@output) {
>    if ($line =~ /\A \s+ VG[ ]Name \s+ (.+) \z/xms) {
>      # found a matching line - extract vg name
>      $tmp_vg = $1;
>    }
> }
>
> defined $tmp_vg
>    or croak("Unable to determine volume group for '$raid'");
> # ------------------- the code -------------------------
>
> print "$raid -> $tmp_vg\n";
>
>
>
> bye
> thomas