At least when the padding is whitespace (which the OP seemed to want), is this solution better than using (s)printf? For ex:

my $string = 'foo';
my $len = 15;
$string = sprintf "%${len}s", $string;
print $string;
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Please note: Don't get me wrong. For fear of fire and brimstone, the Novice that I am would not presume to criticise merlyn. It's just that I've been playing with (s)printf recently, prompting me to change a few old progs from, like:

to:

Have I been I wrong or (more likely), AIMS (Am I Missing Something)?

dave