Crystal Port Scanner

port_scanner_crystal.cr

require "socket"

host = "target_ip"
ports = (1..1024).to_a

channel   = Channel(Nil).new
semaphore = Mutex.new

spawn do
  60.times do
    spawn do
      begin
        while port = ports.pop
          begin
            s = TCPSocket.new(host, port, connect_timeout: 1)
            semaphore.synchronize { puts port.to_s + " Open" }
          rescue
            semaphore.synchronize { puts port.to_s + " Closed" }
          ensure
            s.close if s
            spawn do
              channel.send(nil) # end of operation
            end
          end
        end
      rescue
        # when ya' just can't pop no mo'
      end
    end
  end
end

ports.size.times do
  channel.receive
end