use strict;
use prompt;
use Getopt::Long;

my @size;
my $help;
my $file;
my $okt;

GetOptions("size=i@" => \@size,
           "help" => \$help,
           "file:s" => \$file,
           "okto=o" => \$okt);

print "Size: ",join(",",@size),"\n";
print "Help: ",$help,"\n" if (defined($help));
print "File: ",$file,"\n" if (defined($file));
print "Okto: ",$okt,"\n" if (defined($okt));

__END__

$ perl optl.pl --size=12
Size: 12

$ perl optl.pl --size=12 --help
Size: 12
Help: 1

$ perl optl.pl --size=12 --help
Size: 12
Help: 1

$ perl optl.pl --size=12 --help --size=24
Size: 12,24
Help: 1

$ perl optl.pl --size=12 --help --size=24 --file="hello"
Size: 12,24
Help: 1
File: hello

$ perl optl.pl --size 12 --size 24 --file "hello"
Size: 12,24
File: hello