<b_jonas> perl -e open$I,"<",($n="wisdom/`hello") or die; local$/; $c=<$I>; eof$I or die"e"; $c=~s!/d,/d/!/o,/o/! or die "s"; open $O,">",$n or die"O"; print $O $c or die"p"; warn "edited $f;";

^ (also notated by ⊕ or ⊻) is the exclusive-or operator; ∧ (also notated by /\ or &) is the and (conjunction) operator; ^ (also notated by ↑ or ** or ⋆) is the power operator.