chports

#!/usr/bin/env ruby

abort("usage: #{__FILE__} START_PORT END_PORT") unless ARGV.size == 2

START_PORT = ARGV.shift.to_i
END_PORT = ARGV.shift.to_i

loop do
  used_ports = []
  
  START_PORT.upto(END_PORT).each do |port|
    scan = `lsof -i :#{port}`.chomp
    used_ports << port unless scan.empty?
  end

  break if used_ports.empty?
end