#!/usr/local/bin/perl

use strict;
use warnings;

my $a_file;  # you need an initial value for these names!
my $b_file;  # in case the if statement doesn't work

# quit unless we have the correct number of command-line args
if (@ARGV != 5) {
    print "\nUsage: $0 new_filename orig_filename domain new_tools orig_tools\n";
    exit(-1);
}

#  args
my ( $new_filename, 
     $orig_filename,
     $domain,
     $new_tools,
     $orig_tools ) = @ARGV;
my $psconfig = "psconfig.sh";

if ($new_filename eq $psconfig) {
    $a_file = "/directory/$new_filename" ;
    $b_file = "/directory/$orig_filename" ;
}

open my $a_fh, '<', $a_file  or die "file error $a_file: $!";
open my $b_fh, '<', $b_file  or die "file error $b_file: $!";

my %first_file  = map { chomp; $_ => 1}<$a_fh>;
my %second_file = map { chomp; $_ => 1}<$b_fh>;

print "\n--------------------------------------------\n";
print "Output from $new_tools $domain $new_filename\n";
print "--------------------------------------------\n";


foreach (keys %first_file) {
    print "$_\n" unless exists $second_file{$_};
}

print "\n--------------------------------------------\n";
print "Output from $orig_tools $domain $orig_filename\n";
print "--------------------------------------------\n";


foreach (keys %second_file) {
    print "$_\n" unless exists $first_file{$_};
}