#!/usr/bin/perl -w
use strict;

use Getopt::Long;


my( $username, $password, $group );
my %params = (
	'u=s' => \$username,
	'p=s' => \$password,
	'g=s' => \$group,
);

sub usage
{
	die << "USAGE";
Usage: 
  $0 -u username -p password -g group [-others]

Description:
  whatever...

USAGE
}

usage() unless( GetOptions( %params ) );
for( values %params )
{
	usage() unless defined ${ $_ };
}