#!/usr/bin/perl
#
# This is a callback example
#

use strict;
use warnings;

sub func_print($) { 
	my $s = defined $_[0] ? $_[0] : 'Empty'; 
	print "*CB: $s\n"; 
};

sub main($)
{
	my $callback = shift;

	if (ref $callback ne 'CODE') {
		die("callback must be a code ref but " . (ref($callback) ? ref($callback)." REF" : ref(\$callback)) . " given!\n");
	}

	for (0 .. 10) {
		$callback->($_);
	}
}

main(\&func_print);