my $buf = make_buf(3);
&$buf('hi');
&$buf('moo');
print join('  ', &$buf) . "\n"; # 'hi  moo'
$buf->('foo','no');
print join('  ', $buf->()) . "\n"; # 'moo  foo  no'

sub make_buf {
	my $size = shift || 3;
	my @buf;
	my $pos = -1;
	my $last = $size - 1;
	return sub {
		if (@_) {
			while (@_) { $buf[ $pos==$last ? $pos=0 : ++$pos ] = shift }
		}
		elsif (wantarray) {
			return ($#buf==$last ? @buf[ $pos+1 .. $last, 0 .. $pos ] : @buf);
		}
		else { warn "Call with an argument or in list context"; return; }
	}
}