sub open_file 
{
	my $file = shift || return;
	
	my $lock     = 0;
	my $compress = shift;

	my $fh;

	if($compress) { 
		use IO::Zlib;
		$fh = IO::Zlib->new($file, 'rb') 
			or die "Couldn't open file: $!\n";
	}
	else {
		open($fh, '<', $file) or die "Couldn't open file: $!\n";
	}
	
	if($lock) {
		use Fcntl qw(:DEFAULT :flock);
		flock($fh, LOCK_SH) or die "Couldn't lock file: $!\n";
	}

	return $fh;
}