#!/usr/bin/perl
# paclist - List all packages installed from a given repo
#
# Copyright (C) 2008 Dan McGee <dpmcgee@gmail.com>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

use strict;
use warnings;

my $progname = "paclist";
my $version = "1.0";

if ($#ARGV != 0 || $ARGV[0] eq "--help" || $ARGV[0] eq "-h") {
	print "$progname - List all packages installed from a given repo\n";
	print "Usage:   $progname <repo>\n";
	print "Example: $progname testing\n";
	if ($#ARGV != 0) {
		exit 1;
	}
	exit 0;
}

if ( $ARGV[0] eq "--version" || $ARGV[0] eq "-v") {
	print "$progname version $version\n";
	print "Copyright (C) 2008 Dan McGee\n";
	exit 0;
}

# This hash table will be used to store pairs of ('name version', count) from
# the return of both pacman -Sl <repo> and pacman -Q output. We then check to
# see if a value was added twice (count = 2)- if so, we will print that package
# as it is both in the repo we queried and installed on our local system.
my %packages = ();
my $output;

$output = `pacman -Sl $ARGV[0]`;
if ($? != 0) {
	exit 1;
}
my @sync = split(/\n/, $output);
# sample output from pacman -Sl:
# testing foobar 1.0-1
foreach $_ (@sync) {
	my @info = split(/ /);
	# we only want to store 'foobar 1.0-1' in our hash table
	my $pkg = $info[1] . " " . $info[2];
	$packages{$pkg}++;
}

$output = `pacman -Q`;
if ($? != 0) {
	exit 1;
}
# sample output from pacman -Q:
# foobar 1.0-1
my @local = split(/\n/, $output);
foreach $_ (@local) {
	# store 'foobar 1.0-1' in our hash table
	$packages{$_}++;
}

# run comparison check- if value was added twice, it was in the intersection
my @intersection;
foreach $_ (keys %packages) {
	if ($packages{$_} == 2) {
		push @{ \@intersection }, $_;
	}
}

# print our intersection, and bask in the glory and speed of perl
@intersection = sort @intersection;
foreach $_ (@intersection) {
	print $_ . "\n";
}

#vim: set noet: