file.txt

>> require 'socket'
=> true
>> TCPServer.new "localhost", 5000
=> #<TCPServer:0x100568370>
>> TCPServer.new "localhost", 5000
=> #<TCPServer:0x100530970>
>> TCPServer.new "localhost", 5000
=> #<TCPServer:0x10050e5c8>
>> TCPServer.new "localhost", 5000
Errno::EADDRINUSE: Address already in use - bind(2)
	from (irb):5:in `initialize'
	from (irb):5:in `new'
	from (irb):5
>> TCPServer.new "0.0.0.0", 5001
=> #<TCPServer:0x1023323d8>
>> TCPServer.new "0.0.0.0", 5001
Errno::EADDRINUSE: Address already in use - bind(2)
	from (irb):7:in `initialize'
	from (irb):7:in `new'
	from (irb):7
	from :0
>>