package Number;

use strict;
use warnings;
use IO::File;
use Fcntl ':flock'; 
use Cwd;

sub new{
	my $class = shift;
	my $self = bless{}, $class;
	return eval{
		my $file = $class.".pm";
		$self->{POS} = tell DATA;
		$self->{BUF} = '';
		read DATA, $self->{BUF}, 32;
		$self->{NR} = unpack "A32", $self->{BUF};
		$self->{FH} = new IO::File;
		my $dir = getcwd();
		$self->{FH}->open("$dir/$file", O_RDWR) or die "IO-Error: $!";
		flock $self->{FH}, LOCK_EX or warn "Your system does not support flock";
		$self;
	};
}

sub nr{
	my $self = shift;
	return $self->{NR}++;
}

sub DESTROY{
	my $self = shift;
	$self->{FH}->seek($self->{POS}, 0);
	$self->{FH}->print(pack "A32", $self->{NR});
}

1;
__DATA__
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