use FileHandle;
to_logfile($message) or to_backup_logfile($message, $logfilename);

sub to_backup_logfile {
	my ($message, $logfilename) = @_;
	my $bulog = new FileHandle "$logfilename.bak" or 
		to_backup_logfile("Couldn't write $message to $logfilename!", "$logfilename.bak");
	print $bulog $message;
}