Shortest simplest sweetest web "hello {NAME}" in Ruby

readme.md

This is the shortest "hello {NAME}" Ruby program I could make. It fits in a tweet!

1. Save it as "config.ru"
2. gem install rack
3. Run rackup
4. Visit http://localhost:9292/?name=NAME

config.ru

run ->(e){ p=Hash[*e['QUERY_STRING'].split(/[&=]/)]; [200, {'Content-type'=>'text/html'}, ["Hello #{p['name']}!"]] }

sinatra-helloworld.rb

# Of course, the same thing in Sinatra is way shorter! But I went for minimum dependencies above.
require 'sinatra'; get('/') { "Hello #{params[:name]}!" }