#!/usr/bin/perl

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

@ARGV == 2 and -f $ARGV[0] or die "Usage: $0 list1 list2\n";
my ( $list1, $list2 ) = @ARGV;

my %pathname_versions;

open( IN, $list1 ) or die "$list1: $!";
while (<IN>) {
    next unless ( m:(.+?)#(\d+)$: );
    $pathname_versions{$1}{$2} = undef;

}
	print  Dumper( \%pathname_versions );
open( IN, $list2 ) or die "$list2: $!";
while (<IN>) {
    next unless ( m:(.+?)#(\d+)$: );
	#print "\nLIST 2:$1 $2";
    if ( exists( $pathname_versions{$1} ))
    {
		if ($2 < pathname_versions{$1}{$2} ) {#if the version in list2 is less than version for the same path in list1
			print "$1 pathname_versions{$1}{2}->$2";
		}

        if ( exists( $pathname_versions{$1}{$2} )) {
            # we have a match on version# as well, so...
        }
        else {
            # version number wasn't seen in list1, so...
        }
    }
}