#!/usr/bin/perl -w
#
# $Id: get_software_version.pl,v 1.1 2005/10/23 22:36:46 jmates Exp $
#
# Copyright (c) 2005, Alex Dioso.
# All rights reserved.
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#
#####################################################################
#
# Get the highest version of all software that matches the argument.
# Becareful because there could be different software that has the
# similar strings in the name like Mozilla, Mozilla Firefox, Mozilla
# Thunderbird.
#
# Added option, if you specifiy a version number as the last argument
# this script will compare that with the installed version. If the given
# version is higher then return 1, else return 0.

use strict;

use Win32::TieRegistry ( Delimiter => "/" );

usage() unless ( ( scalar @ARGV ) == 1 );

my $software = shift;
my $version  = 0;

my $Uninstall =
  $Registry->{
  "LMachine/SOFTWARE/Microsoft/Windows/CurrentVersion/Uninstall/"};

for my $key ( keys %{$Uninstall} ) {
  if (  exists $Uninstall->{"$key/DisplayName"}
    and exists $Uninstall->{"$key/DisplayVersion"} ) {
    if ( $Uninstall->{"$key/DisplayName"} =~ m/$software/ ) {
      my $temp_ver;
      ($temp_ver) = ( $Uninstall->{"$key/DisplayVersion"} =~ m/([0-9.]+)/ );
      $version = get_higher_version( $version, $temp_ver );
    }
  }
}

print "$version\n";

sub get_higher_version {
  my @first  = split /\./, shift;
  my @second = split /\./, shift;

  # We want the smaller array so we don't run beyond
  # if the arrays are even up to the last element of the smaller array
  # then the larger array is the newer version
  my $size = scalar @first < scalar @second ? scalar @first : scalar @second;

  for ( 0 .. $size - 1 ) {
    if ( $first[$_] > $second[$_] ) {
      return join ".", @first;
    } elsif ( $first[$_] > $second[$_] ) {
      return join ".", @second;
    }
  }

  # If we get here then the arrays are equal up to the smaller array so the
  # larger array must be the higher version
  return join ".", ( scalar @first > scalar @second ? @first : @second );
}

sub usage {
  print <<EOF;
\nusage: $0 \"DisplayName string to search for\"\n
\nReturns the highest version of the software as found in
HKLM/SOFTWARE/Microsoft/Windows/CurrentVersion/Uninstall/*/DisplayName
or 0 if not found.  If 0 is returned, the software may still be
installed, it just may not have a proper installer.\n
EOF
  exit;
}