I am creating a script which when given a date range, will grab certain files created during those dates, in order to determine what differences exist, if any. I was planning on using Array::Compare to make my comparisons.

Here is some code:

  #!/usr/local/bin/perl 

use strict;
use Array::Compare;

##############################
# Define some variables here #
##############################

my ( @pub, @priv, @as, @files, @lines ); 
my ( $num, $from, $to, $AS, $privstring, $pubstring, 
     $element, $beg_priv_file, $beg_pub_file, $comp_file, 
     $as_dir, $line );
my $dir = "path-to-peering-files";

###################
# test invocation #
###################
 
die "\nUsage: $0 <AS> <yyyymmdd-yyyymmdd>\n
This program will take peering files, as per AS specified on 
the command line
     where AS = [123, 456, 789, 111, 222]
     choose multiple AS's by comma-separating them 
     for example, \"123,456,789\"
     -a to process all valid AS's\n\n"  unless @ARGV;

 unless (($from, $to) = $ARGV[1] =~ /(\d{8})-(\d{8})/) { 
   die "Invalid dates or date format\n"; 
 }
 unless ($from < $to){
   die "Invalid date range\n";
 }
 $AS = $ARGV[0];
 my @as = split(",", $AS);
 
 foreach $num(@as){
   die "AS $num is not recognized. 
        Please choose [123, 456, 789, 111, 222]\n"
     unless ($num == 123  || $num == 456 || $num == 789 
             || $num == 111 || $num == 222 || $num == "-a");
 }

#########################
# Set AS(s) to process  #
#########################

 if ($AS == "-a"){
@as = qw(123 456 789 111 222);
}
##############################
# Begin file processing here #
############################## 

 foreach $num(@as) {
&get_routers($num);
}

###############
# SUBROUTINES #
###############

sub get_routers {

####################################
# set file prepend according to AS #
####################################

 if ($num = "123") {
   $privstring = "private-peering.";
   $pubstring = "public-peering.";
   $as_dir = "$dir/AS$num"; 
   }
 elsif ($num = "456") {
   $privstring ="global-public-peering.";
   $pubstring = "global-private-peering.";
   $as_dir = "$dir/AS$num"; 
 }
 elsif ($num = "789") {   
   $privstring = "ebiz-public-peering.";
   $pubstring = "ebiz-private-peering.";
   $as_dir = "$dir/AS$num"; 
 }
 elsif ($num = "111") {
   $privstring = "euro-public-peering.";
   $pubstring = "euro-private-peering.";
   $as_dir = "$dir/AS$num"; 
 }
 else {
   $privstring = "asia-public-peering.";
   $pubstring = "asia-private-peering.";
   $as_dir = "$dir/AS$num"; 
 }
 
 }
opendir (DIR, $as_dir) || 
die "Cannot open $as_dir: $!.\nRestart this program without AS$AS, 
     or go find out what's wrong, and re-run the program.\n";

@files = grep { /(\d{8})/ && $1 >= $from && $1 <= $to } readdir DIR;  

###############################################
# push private-peering files into an array,   #
# and public-peering files into another array #
###############################################

foreach my $t(@files){ 
  if ($t =~/^$privstring(\d+$)/){
    push(@priv, $t);  
  }
      elsif ($t =~/^$pubstring(\d+$)/){
    push(@pub, $t);
      }     
       }
      $beg_priv_file  = shift(@priv);
      $beg_pub_file  = shift(@pub);
      
open (BEG_PRIV_FILE, "$as_dir/$beg_priv_file") || 
      die "Cannot open: $!\n";  
    LINE: while (<BEG_PRIV_FILE>){
    chomp;
    if (/unknown/) { next LINE;}
    elsif (/shutdown/) { next LINE;} 
    @lines = $_;
      }
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This is where I am stuck. I don't know how to open each of the other files in  @priv and  @pub and write them to dynamically created arrays; one for each file. And, as I'm writing this I just realized that in order to be accurate, I will need to:

now this is pseudo-code, so don't bash me here!

if $element(@beginning_file) doesn't exist in @next_file
      Print something to STDOUT that I will define later.
AND if $element(@next_file) doesn't exist in @beginning_file
      Print something else to STDOUT that I will define later
[download]

I'm really stuck. Can anyone help me out?