Ruby? It has perlisms and awkisms around, here's a stupid example:

    echo -e "foo 1\nbar 2\nbaz 3" | ruby -n -e 'BEGIN { puts "===" }; $_ =~ /^b\S+ (.*)/ and puts "#{$_.chomp.upcase} => #{$1}"; END { puts "===" }'

There's -p too, -0777 works for slurp mode, throw in -rjson to get battery-included pretty_generate, interpolation can be nicer, but $_ is not implicitly used so it can get a bit more verbose than Perl.

I meant average line ratio, not literal one-liners, apologies for confusion.

When you're talking about doing things interactively (in a shell, either directly via a terminal or indirectly via an editor) then the constant factors matter far more than the asymptotics. This has always been perl's target for optimization. That's why it has a million obscure operators that no other language has.