use Data::Dumper;
use Carp;
use strict;
use warnings;

sub write_to_file {
    my ($file,$data,$small)=@_;
    open my $OUT,">$file" or croak "Error with $file:$!";

    my $dumper=Data::Dumper->new([$data],["my_dump"]);
    $dumper->Indent($small ? 0 : 2);
    print $OUT $dumper->Dump;

    close $OUT;
    return $dumper->Dump;
}

sub read_from_file {
	my $file=shift;

	local $/;
	open my $IN,"$file" or croak "Error with $file:$!";
	my $data=<$IN>;
	close $IN;

	my $my_dump;
	eval $data;
	croak "from $file I get error $@" if $@;

	return $my_dump;
}

my $test={key=>[qw(this is a list)],
          subhash=>{qw(so is this one but it must have pairs inside)}};
write_to_file("test_dumper.dmp",$test);
my $var=read_from_file("test_dumper.dmp");
print Dumper($test,$var);