#!/usr/local/bin/perl  -wl

use Getopt::Long;

my $config = "default";

my $result = GetOptions("config=s" => \$config);

print "result = $result";
print "config = $config";
__END__
    
> monk.pl
result = 1
config = default
> monk.pl --config
Option config requires an argument
result = 
config = default
> monk.pl --config=foo
result = 1
config = foo