#!/usr/bin/perl

# Prints a list of the largest packages when 
# about to execute a 'apt-get upgrade', especially
# helpful for us poor souls on dial-up. A quick
# un-install of an un-wanted package can save
# *tons* of download time.
#
# Paul Boin   pboin@intertechconsulting.net

$cvsId = q$Id: apt-topten,v 1.3 2004/04/05 21:34:57 paul Exp $;

use strict;
use warnings;
use Getopt::Std;

my %packages;
my %options;
my $i = 0;

get_options();	
get_packages();
&print_tops($options{n});
exit;

sub print_tops(){
	my $number = shift;
	my $package;
	my $i;
	my @sorted_by_size;
	print "Package" . ' ' x 23 . "Bytes\n";
	print '=' x 60 . "\n";
	foreach $package (sort {$packages{$b} <=> $packages{$a}} keys %packages) {
		push @sorted_by_size, ($package . (' ' x (30 - length($package))) . $packages{$package});
	}
	for ($i=0; $i<$number; $i++){
		print "$sorted_by_size[$i]\n";
	}
}

sub get_packages {
	my $list = `apt-get -u -V --trivial-only upgrade 2> /dev/null`;
	my $capture = 0;
	while ($list =~ /^(.*)$/gm){
		my $line = $1;
		if ($capture){
			if ($line !~ /^\ \ \ /){$capture = 0;next;}
			$line =~ m/^\ \ \ (\S+).*?=>\ (.*)\)$/;
			$packages{$1} = get_package_size($1,$2);
		}
		if ($line =~ /will be upgraded/){$capture = 1;}
	}
}

sub get_package_size {
	my $name = shift;
	my $ver  = shift;
	my $cmd = "apt-cache --no-all-versions show $name";
	my $result = `$cmd`;
	$result =~ /^Size:\ (.*)$/m;
	return $1;
} 

sub get_options {
	my $usage = qq{Usage: $0 options

	-h : This help message.
	-n : Number of packages to list (Default = 10)

	Prints a list of the largest packages that 
	'apt-get upgrade' wants to download.
	} . "\n";
	getopts('n:h', \%options);
	die $usage if $options{h};
	$options{n} ||= 15;
}