Getopt::Std (which you use but never use) gets you most of the way there.

#!/usr/bin/perl -w

use strict;
use Getopt::Std;
use Data::Dumper;

my %switches;

getopts('x:o:d:m:', \%switches);

print Dumper \%switches;
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Running it gets you:

$ ./test.pl -o outputfile -x xmlfiles -d disk1 -m memory1         
$VAR1 = {
          'm' => 'memory1',
          'd' => 'disk1',
          'x' => 'xmlfiles',
          'o' => 'outputfile'
        };
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The problem is, of course, with your multi-valued options. If you could make one small change to the way you pass them into the program then this would be very simple.

#!/usr/bin/perl -w

use strict;
use Getopt::Std;
use Data::Dumper;

my %switches;

getopts('x:o:d:m:', \%switches);

foreach (keys %switches) {
  $switches{$_} = [ split /\s+/, $switches{$_} ];
}

print Dumper \%switches;
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The one problem is that you have to quote the multiple keys like this:

$ ./test.pl -o outputfile -x xmlfiles -d 'disk1 disk2' -m 'memory1 mem
+ory2'
$VAR1 = {
          'm' => [
                   'memory1',
                   'memory2'
                 ],
          'd' => [
                   'disk1',
                   'disk2'
                 ],
          'x' => [
                   'xmlfiles'
                 ],
          'o' => [
                   'outputfile'
                 ]
        };
[download]

--
<http://www.dave.org.uk>

"The first rule of Perl club is you do not talk about Perl club."
-- Chip Salzenberg