The FishNet protocol

Your program (a client) will communicate with another player (also a client) via a server. The server runs on port 1530 of brussels.lti.cs.cmu.edu (IP address 128.2.211.107).

The server's job is to pair players together, to deal cards, to referee the game, and to notify players of the game's progress. The server keeps track of both players' hands and takes care of forced communication (replying to requests and revealing books) on its own. It frequently sends information to the clients about the progress of the game, and it prompts the clients to choose which rank to request when appropriate. The client's primary tasks, therefore, are to keep track of what is in the hand (based on the server's messages) and to generate requests when the server prompts the program to do so. Your program may assume the server referees the game properly; very few of the rules will need to be incorporated into the program.

Sample FishNet session

In this sample transcript of communication between server and client, messages from the server are in boldface, and messages from the client are in normal type. Italicized comments describe what is happening and are not part of the communication.

play cburch spot  You identify yourself and who you want to play
fish 3            Server deals the hand 2,2,3,4,4,9,12 to you
fish 4
fish 2
fish 2
fish 4
fish 9
fish 12
oppmakes 0        Spot made a book of four 0s during the deal
fish 2            You are dealt your seventh card
yourturn          Server chose you to go first
request 4
oppgives 2 4      Spot had two of the 4s you requested
youmake 4         Server announces you completed a books of 4s
yourturn          Server tells you to go again
request 12
fish 8            Spot had none; you draw an 8
request 2         Spot requests 2s (you lose two 2s)
request 2         Spot requests 2s again (you lose none)
oppmakes 2        Spot completes a book of four 2s
youlose           Spot is out; with two books to your one, Spot wins
quit

In this game, Spot receives seven cards in the deal and happens to complete a book of 0s, leaving three cards. Spot loses two of these when you request 4s, leaving one card. Then, when it becomes Spot's turn, Spot holds a single card. Spot requests 2s, of which you have two. Spot requests 2s again, and of course you have none. But Spot fishes a 2, completing a book. Since Spot fishes the same card as requested, Spot gets another request. But Spot has no cards; thus the game ends. Spot has two books (of 0s and 2s) while you have one (of 4s), so you lose.

Messages from client

Each FishNet message consists of an operation, followed by some arguments separated by spaces, followed by the end of a line. The following describes FishNet operations that your client might send.

• pass Forfeit a turn. (A Level 1 program will not use this message.) Unless you passed in your last turn also, you do not fish. The server sends this message when your opponent passes.

• play Begin a game. It has two arguments, both strings. The first should be a name for your team (this name will be directly in the program code). The second argument is the name of the opponent you would like to play.

  When the server receives this request, it sees if it has any opponent by the requested name waiting for you. If so, it begins a game. If not, it sends nothing to the client until an opponent of the desired name requests a game with you. Note that the choice of which opponent plays first is always randomly chosen by the server.

  Built into the server are six players always available to play.

  spot	plays completely randomly
  bob	remembers a few of your past moves
  alice	remembers everything possible about your hand
  smarx	PGSS 1998 champion, by Steve Marx
  rdore	PGSS 1999 champion, by Richard Dore
  neo	PGSS 2000 champion, by Matti Klock
  heathcliff	PGSS 2001 champion, by Brian Heath, Megan Keen, and Jacob Widlitz
  et	by Ethan Tira-Thompson, PGSS 2001 TA

• quit The client is about to hang up. This should be after a game is complete. (If the client wants to play another match instead, it can send an additional play message.)

• request Request a rank from the opponent. (The server will tell you the response and notify the opponent of your request.) The single argument, between 0 and 12, specifies which rank you request.

• taunt Send a message to the opponent. (This message need not be used at all by your program.) The single argument is a string including no spaces. On receiving this message, the server will forward it onto the opponent. Though intended for sending taunts, this feature can be used to send positive, reinforcing messages to your opponent also (e.g., ``taunt Good_job!''.

  The server will add an exclamation mark to the beginning of your message before forwarding your taunt to your opponent. This is so that your program can't confuse clients that do not support taunt messages. Otherwise program A might send, say, taunt youwin to B, convincing B that the game is over. Then B would close the connection, and A would win by forfeit.)

  Warning: If during a player's turn the player sends more than 5 taunts with no intervening passes or valid card requests, the player is considered to have forfeited.

Messages from server

Following are messages that the server might send to the client.

• error The server encountered a problem, usually because of something the client did. It has a single argument, which is a string with no spaces describing the error. When the client receives this type of message, it should print the error description to the screen and attempt to continue.

• fish Your client draws a card. This happens in the initial deal and when the client requests a rank the opponent does not have. The single argument, between 0 and 12, tells the rank of the drawn card.

• oppgives Your opponent gives you some cards you requested. The first argument tells how many of the cards the opponent gives, and the second argument tells their rank.

• oppmakes Your opponent completes a book. The argument tells the rank of the book.

• pass Your opponent passes.

• request Your opponent requests a rank. The single argument, between 0 and 12, specifies which rank you request. Note that your program should not send any response to this request. (The server, who also knows what is in your hand, will send the forced response to your opponent.)

• taunt Your opponent sends you a message. (Spot occassionally sends such a message.) The single argument is a string including no spaces. You can simply ignore this message if you would like.

• tiegame The game ends in a tie game.

• youlose The game ends; your opponent won.

• youmake You complete a book. The argument tells the rank of the book.

• yourturn The server prompts you for a request. The client should respond with a request or a pass message.

• youwin The game ends; you win.