You should check perldoc perlrun, in particular you're likely to be interested in -n, -p, or the "chomping versions" -ln, -lp, possibly with inline modifying, -i and/or with changing the input record separator...

As for PM's Super Search, try with "oneliners" et similia, although the results won't be focused on conversions from sed, they're likely to solve tasks similar to the ones you're interested in.