#!/usr/bin/perl

use strict;

my @lines;
open(D, $ARGV[0]) || die("Could not open file!\nUsage: $0 file ");
@lines = <D>;
close(D);

my %count;
foreach (@lines) {
        next if /^#|^(\s)*$/;
        chomp;
        my ($ipa, $ipb, $bytes) = split /\t\s?/;
        if((grep /$ipb/, %count) && (grep /$ipa/, (%{$count{$ipb}})))
                {
                $count{$ipb}{$ipa}+=$bytes;
                }
        else
                {
                $count{$ipa}{$ipb}+=$bytes;
                }
        }

foreach my $key(keys %count){
        foreach my $k(keys %{$count{$key}}){
        print "${key}\t$k\t$count{$key}->{$k}\n";
        }
}