#!/usr/bin/perl -w
use strict;

my %all;

open(INPUT,"<coconet.dat") || die "Can't open coconet.dat";
while (<INPUT>) {
	if ($_ =~ /^#/) { next }
	my ($src, $dest, $bytes) = split;
	# hash of hashes holds the from->to transmission TOTALS; we do not keep all the data
	$all{$src}{$dest}+=$bytes;	
}
close(INPUT);

# simple use of map to create array of references to hashes: my @reflist = map { \%{$all{$_}} } keys %all;
# so...create an array of references to arrays (from map callback) of scalars and REFS TO existing hashes and new anonymous arrays! 
my @reflist = sort { $$b[2] <=> $$a[2] } map buildlist($_), keys %all;  
# sort by the total of TOTALS 

foreach my $ref (@reflist) { 
	print "$$ref[0] $$ref[2]\n";
	# the next two are the same:
	 foreach my $line (@{$ref->[3]}) { print "\t$line ${$ref->[1]}{$line}\n" }
	# foreach my $line (@{$$ref[3]}) { print "\t$line ${$$ref[1]}{$line}\n" }
}

sub buildlist {
	my $site = $_;
	my @tmp;
	$tmp[0]=$site;
	$tmp[1]=\%{$all{$site}};
	foreach (keys %{$tmp[1]}) { $tmp[2]+=${$tmp[1]}{$_} }
	# make element 3 a reference to an anonymous array of scalars (the dest site names, ranked)
	@{$tmp[3]} = sort { ${$tmp[1]}{$b} <=> ${$tmp[1]}{$a} } keys %{$tmp[1]};
	return \@tmp;   # 0=site name, 1=hash ref, 2=total bytes for all transmissions from site, 3=ranked dest names ref
}

__DATA__
2000 lines, eg:
gilligan.crew.hut lovey.howell.hut 4721
thurston.howell.hut lovey.howell.hut 4046
professor.hut ginger.girl.hut 5768
gilligan.crew.hut laser3.copyroom.hut 9352
gilligan.crew.hut maryann.girl.hut 1180
fileserver.copyroom.hut thurston.howell.hut 2548
skipper.crew.hut gilligan.crew.hut 1259