Query Source Servers

source_query.rb

#!/usr/bin/ruby

require 'socket'

class SourceQuery
  def initialize(ip, port)
    query(ip, port)
  end

  def to_s
    "%s | %s | %d/%d" % [@name, @map, @players, @max_players]
  end

  private
  def query(ip, port)
    sock = UDPSocket.new
    data = [-1, -1, 'T', 'Source Engine Query'].pack('s2aa*x')
    sock.send(data, 0, ip, port)
    ready = IO.select([sock], nil, nil, 5)
    if ready
     parse(sock.recvfrom(1024))
    else
      raise "server not responding"
    end
  ensure
    sock.close
  end

  def parse(data)
    unpacked = data[0].unpack('@6Z*Z*Z*Z*s!CCCaaCC')
    keys = [:name, :map, :folder, :game, :id,
            :players, :max_players, :bots,
            :server_type, :environment,
            :visibility, :vac]
    info = keys.zip(unpacked).to_h
    info.each do |key, value|
      self.class.send(:attr_reader, key)
      instance_variable_set("@#{key}", value)
    end
  end
end

def run!
  server = SourceQuery.new(*ARGV.first.split(":"))
  puts server
end

run! if __FILE__ == $0