# main perl script
my $input;
# defining ReadLine module for supporting
my $term = new Term::ReadLine 'Command Line Interface';
print "\nWelcome to my command line interface (version $version)!\n\n";
while (defined($input = $term->readline("\n" . $prompt.' (main, exit, back, help) > '))) {
  chomp $input;
  $input =~ s/^\s+//;   # delete leading spaces
  $input =~ s/\s+$//;   # delete trailing spaces
  &parseCmdLine();
  ...
}
sub parseCmdLine {

...
  local %hash;
  if (GetOptions(\%hash, 'netbios=s', 'winbind!', 'srvstring=s')) {
	&doSomething();
  }
...

}