sub usage { pod2usage(-exitval => 1, -verbose => 0); }
sub help  { pod2usage(-exitval => 0, -verbose => 0); }
sub man   { pod2usage(-exitval => 0, -verbose => 2); }

if (!GetOptions(
   'config|c=s' => \$config,
   'stop'       => \$stop,
   'start'      => \$start,
   'help|?'     => \&help,  # Show help and exit.
   'man'        => \&man,   # Show man and exit.
)) {
   # A bad argument was encountered.
   # Show help and exit with error.
   usage();
}

if (!$stop && !$start) {
   # At least one of the commands needs to be specified.
   # Show help and exit with error.
   usage();
}