Get next free port on Linux with Ruby

Get next free port:

require 'socket'
(1..10).each do |n|
socket = Socket.new(:INET, :STREAM, 0)
socket.bind(Addrinfo.tcp("127.0.0.1", 0))
port = socket.local_address.ip_port
puts "port -> #{port}"
socket.close
end

command line:

port=$(ruby -e "require 'socket'; \
s = Socket.new(:INET, :STREAM, 0); \
s.bind(Addrinfo.tcp('127.0.0.1', 0)); \
port = s.local_address.ip_port; \
s.close; \
p port")