105
26
Write a program or function that listens for incoming TCP traffic on port N. It offers a simple service: it calculates sum of IP address fields of incoming connection and returns.
Program or function reads integer N from arguments or stdin. It listens to incoming TCP connections on port N. When someone connects to that port, the program calculates sum of its IP address fields and sends it back to the client with trailing newline and closes connection.
- Port number N is a valid port, and 210 < N < 215
- Trailing newline can be either
\n
or\r\n
- You can use either IPv4 or IPv6. Since IPv6 addresses are written in hexadecimal form, you must also provide result in same format, for example
2001:0db8:0000:0042:0000:8a2e:0370:7334 => 12ecd
.
This is code-golf. Standard rules and loopholes apply.
Example
You run your server with ./server 1234
. The server is now running and waiting for connections on port 1234. Then a client from 127.0.0.1
connects to your server. Your server performs a simple calculation: 127+0+0+1 => 128
and sends the result to the client (with trailing newline): 128\n
. Then server closes connection and waits for next client.
Leaderboard
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1Is it allowed to use inetd/xinetd or similar? – Digital Trauma – 2016-03-28T18:17:34.257
93I like this, since it's a golfing challenge that golfing languages are unlikely to be very good at. – isaacg – 2016-03-28T18:54:21.263
9Not only is it amazing that a TCP server is apparently a very easy program to write, I am thoroughly floored at the fact that it's getting golfed for fun. I'll just go back to struggling with FizzBuzz like an imbecile. – MonkeyZeus – 2016-03-29T19:50:22.577
17@isaacg It's only time before someone finds the TCP server built-in in Mathematica – Downgoat – 2016-03-29T22:19:46.587
3@MonkeyZeus To be fair, you will not see any good TCP server here. Making a reliable, scalable TCP server that handles all the intricacies of TCP (and your application protocol) well is a bit harder :D Though it certainly helps that the protocol is exceedingly simple - you don't even need to read the stream, something that I've seen broken in too many TCP servers to count :D – Luaan – 2016-03-30T09:11:30.710