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

config.ru

run ->(e){ n=e['PATH_INFO'][1..-1]; [200, {'Content-type'=>'text/html'}, ["Hello #{n}!"]] }

sinatra-helloworld.rb

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

webrick-helloworld.rb

# WEBrick equivalent, if we're limiting ourself to only Ruby stdlib and no dependencies
require 'webrick'
server = WEBrick::HTTPServer.new :Port => 8000
server.mount_proc('/') {|req, res| res.body = "Hello #{req.query['name']}!" }
trap('INT') {server.shutdown}
server.start

zomg-no-deps.rb

# Just ruby, not even WEBrick!
# Submitted by https://github.com/reu
require "socket"
socket = Socket.new(Socket::AF_INET, Socket::SOCK_STREAM, 0)
socket.bind(Socket.pack_sockaddr_in(3000, "localhost"))
socket.listen(1)
loop do
  connection = socket.accept[0]
  connection.gets.match /name=(.+) (.+)/
  connection.write "#{$2} 200 OK\nContent-Type: text/html\n\nHello #{$1}"
  connection.close
end