#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

my %hash = ( 'file1' => 'line common',
	     'file2' => 'line common', );

print Dumper \%hash;

__END__

$ perl test.pl
$VAR1 = {
          'file1' => 'line common',
          'file2' => 'line common'
        };