#! perl
use strict;
use warnings;
use Getopt::Long;

my ($name, $long);

GetOptions
(
    'name=s' => \&name_handler,
     long    => \$long,

) or die "Error in command line arguments\n";

printf "Name is '%s', long is %s\n", $name, $long ? 'set' : 'not set';

sub name_handler
{
    my (undef, $n) = @_;

    if ($n =~ /^--/)
    {
        die "Option 'name' requires an argument\n";
    }
    else
    {
        $name = $n;
    }
}

##</code><code>##

 2:11 >perl 1098_SoPW.pl --name Fred --long
Name is 'Fred', long is set

 2:11 >perl 1098_SoPW.pl --name --long
Option 'name' requires an argument
Error in command line arguments

 2:11 >