Style A:
[src]
$str="me you do me them you does do";
@nondub =split " ", $str;
@nondup =grep { ! $str{$_}++ } @nondub ;
print join(' ',@nondup );
[/src]



Style B:
[src]
$str="me you do me them you does do";
@nondub =split " ", $str;
@nondub =sort keys %{+{ map { $_, 1 } @nondub}};
print join(' ',@nondub);
[/src]

output
[src]
do does me them you
[/src]