TIMTOWDI, but I would suggest you replace:

 my $data;
open my $FH, '<' , $config or die "Cannot open $config: $!\n";
local $/ = undef;
s/^\s*#.*\n|^\n//gm for $data = <$FH>;
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with

open my $FH, '<' , $config or die "Cannot open $config: $!\n";
local $/ = undef;
my $data = <$FH>;
 $data =~ s/^\s*#.*\n|^\n//gm;
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The use of the for loop on a value you expect to be scalar confuses casual perusal, and you've declared the variable (my) at a different spot than where you initialize it. If you want to go compound, there's always

(my $data = <$FH>) =~ s/^\s*#.*\n|^\n//gm;
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but that feels crowded to me. If I were actually writing this, I would do:

my $data = do {
    local $/ = undef;
    open my $FH, '<' , $config or die "Cannot open $config: $!\n";
    <$FH>;
};
$data =~ s/^\s*#.*\n|^\n//gm;
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Slurping in a do loop keeps the filehandle tightly scoped and keeps that localization of the input file separator actually local. And note, even then, I personally prefer keeping the processing separate from the import.

Update: Fixed typos; haukex++

Update: Fixed typos; haukex++. Some days you just shouldn't post code.