Having thought about this a little more, would a source filter work? It's a little more fragile than the -N switch, doesn't play well with -p, but requires only the Filter::Simple module. That'll be standard in 5.8, unlike my patch. Probably. :)

package NFlag;

use Filter::Simple sub {
    s/^([^#].+)/LINE: while (<DATA>) {\n$1\n}\n/ms;
};

'to demerphq';
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Also save this code as 'stdinhack.pl':

#!/usr/bin/perl -w
use strict;

print scalar reverse $_;

__DATA__
sdrawkcab
niaga
tub
retrohs
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Then you can call it with the command line perl -MNFlag stdinhack.pl.