use IO::Tee;
my $tee = IO::Tee -> new(">stdout.txt", \*STDOUT);
print $tee "Cheese!\n";

##</code><code>##


my $log = 0;
print "Do you want to log to a file?";
my $resp = <STDIN>;
if ($resp =~ /^y/i) {
   $log = IO::Tee -> new(">stdout.txt", \*STDOUT);
}
...
if $log {
   print $log "What did I want to say?\n"
} else {
   print "What did I want to say?\n"
}

##</code><code>##

my $tee;
sub log_to_file {
	my ($on, $logfile) = @_;
	if ($on) {
		$tee = IO::Tee->new(">>$logfile", \*STDOUT);
		select $tee;
		print "Logging console window to $logfile\n";
	} else {
		print "Console window log OFF.\n";
		undef $tee;
		select STDOUT;
		close $logfile;
	}
}


##</code><code>##

sub log_to_file {
   my $on = $_[0];
   if ($on) {
      Log::Log4perl->easy_init ({
	    level => $DEBUG,
        file => 'STDOUT',
        layout => '%m',
        },
        {level => $DEBUG,
        file => ">> $console_log",
        layout => '%m',
        });
   } else {
      Log::Log4perl->easy_init ({
	    level => $DEBUG,
        file => 'STDOUT',
        layout => '%m',
        });
   }
}