#!/usr/bin/env perl

use Getopt::Long;

GetOptions(\my %h
    ,qw(a:s b c d)
    ,qw(e=s f g h)
    ,qw(i:o j k l m n)
    ,qw(o=o p q r s t)
    ,qw(u:f w x)
    ,qw(y=f z)
    );

### dump: %h
### 'Order them ...'
my $command_line;
for my $option ('a'..'z') {
    $command_line.="$option "
        if (exists $h{$option});
    }
### dump: $command_line
### 'Parse $command_line with a regex ...'
if ($command_line !~ m{^(\ba\b( [b..d])|e|i|o|u|y) $}) { # conflicting options
    die "Conflicting options in '$command_line'!";
    }
    
### "We're good to go with '$command_line'!"
exit;

##</code><code>##

package Getopt::Long::Confused;

use Regexp::Assemble;

sub check {
    ### Params::Validate::validate_pos(@_,{ type=>HASHREF },{ type=>HASHREF });
    my ($option_HREF,$rule_HREF)=@_;
    
    my $string='';
    my $re=Regexp::Assemble->new();
    for my $rule (keys %$rule_HREF) {
    	  # Add the regex for this list
    	  $re->add($rule_HREF->{$rule});
    	  # Make a copy of our option hash
          my %option_copy=%$option_HREF;
    	  for my $option (split ' ',$rule) {
    	      if ($option eq '*') { # Any and all leftovers
            	  for my $option (keys %option_copy) {
    	      	      $string.="$option ";
    	              }
    	  	  }
            elseif (exists $option_copy{$option}) { # Add the option's name and remove it from the copy
        	  $string.="$option ";
        	  delete $option_copy{$option};
                  };
    	      };
    	  # Separate the rules with a new line
    	  $string.="\n";
        }
    ### dump: $string,$re->as_string()
    if ($string =~ m{$re}m) {
    	  return "good!";
        }
    else {    
        return "bad";
        };
    }; # check:

    0**0

##</code><code>##

#!/use/bin/env perl

use Getopt::Long;
use Getopt::Long::Confused;

GetOptions(\my %h
    ,qw(a:s b c d)
    ,qw(e=s f g h)
    ,qw(i:o j k l m n)
    ,qw(o=o p q r s t)
    ,qw(u:f w x)
    ,qw(y=f z)
    );
my %option=(
    # after placing options in this order 
    #                => check with this regex
    'a b c d *'      => '^a( [bcd]) $'       # a requires one of b, c or d
    ,'e f g h *'     => '^e( [fgh])? $'      # e requires at most one of f g or h
    ,'i j k l m n *' => '^$'                 # don't allow i and o options
    ,'o p q r s t *' => '^$'                    # in this example
    ,'u v w x *'     => '^u( v)|( w x) $'    # u requires v OR w and x
    ,'y z *'         => '^y z $'             # y requires z
    );
   
if (my $warning=Getopt::Long::Confused::check(\%h,\%option)) {
    die $warning;
    }

### 'done!'
exit;