use strict;
use warnings;
use Getopt::Long;


GetOptions(
           'demo' => \&demo,
           'test!' => \&test
          )
  or die("Error in command line arguments\n");


sub test {
    die "expected 2 args" if @_ != 2;
	warn join ",",@_;
#	demo("hello", "world");
}
__DATA__


##</code><code>##

C:/Strawberry/perl/bin\perl.exe -w d:/tmp/pm/getopt_long.pl --no-test
test,0 at d:/tmp/pm/getopt_long.pl line 16, <DATA> line 28.