use warnings;
use strict;

my @first_list;
my @second_list;
my %first_lc;
my @second_lc;

open FIRST_LIST, "< first_list.txt" or print $! "\n";
@first_list=<FIRST_LIST>;
close (FIRST_LIST);
chomp (@first_list);

open SECOND_LIST, "< second_list.txt" or print $! "\n";
@second_list=<SECOND_LIST>;
close (SECOND_LIST);
chomp (@second_list);

# create look up of machines in lower case
my %first_lc = map { lc => 1 } @first_list;
# not stricty necessary could use map in loop
my @second_lc = map { lc } @second_list;

print "Machines extra in second list\n\n";
foreach my $unique (@second_lc)
{
    if (exists $first_lc{$unique})
    {
        print "already there $unique\n\n";
    } else {
        print "newly in this $unique\n\n";
    }
}