hangman-socket-cpp

IST Computer Networks course's project (LEIC-A 2022/2023). Made by João Cardoso and José João Ferreira.

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Brief description

This is an implementation of a Hangman Game, which consists in a client/server application, where communication between server and client is achieved by using both UDP and TCP sockets.

We opted to write the code in C++, in order to make use of some of its higher level functions, especially when it comes to input/string parsing. The player and gs executables are both compiled using the provided Makefile and represent the Player and the Game Server, respectively.

We have decided to strictly follow the project specifications. In cases where that was not possible, we tried to emulate the behavior of the server that was up while we were developing the project, which was tejo.tecnico.ulisboa.pt:59000. In the rare situations where that was not possible, we implemented the specifications according to our best judgment.

In the auxiliary.h file, we have put the auxiliary functions that are made use of in both the client and server files, since the project dimension did not, in our opinion, call for further division into more files, which would decrease readability. We also rewrote portions of the auxiliary functions that were provided so that they would be more in line with the C++ programming style.

Occasionally, we use the server/temp directory in order to have a place to store the scoreboard and state files before sending them. This directory is deleted when the server stops executing and the same applies to the active games (files starting with "GAME_") left unfinished inside the directory server/games.

The hint images for the words in the words file must be stored inside the server/images.

To stop the Game Server from running, you must press Ctrl+C while in the terminal. This sends the SIGINT signal, which is handled by a function that we defined to close the Game Server safely. The same logic applies to the executable of the Player.

Sockets are particularly useful to processes running separately and that need to communicate with each other, exchanging data. You can run the Player and Game Server wherever you want, as long as you know the IP of the machine running the Game Server and establish a known port.

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How to use

Making use of Domain Names/IPs and Ports, you can:

• run both the Player and the Game Server locally;
• run the Player locally and connect to an external Game Server;
• run the Player externally and connect to a local Game Server.

1. In order to run the Player and Game Server, firstly, you need to compile the code:

make

2. Then, you need to start the Game Server with the set of words and hints provided in the file server/words.txt, run:

./gs words.txt [-p gsPort] [-v]

If you wish to change the set of words being used, you can edit them manually. However, be aware that every hint associated with a word must have its own image file in the server/images. The default port being used for the UDP and TCP sockets is 58092. To use a custom port for communication, use the -p flag and specify it in the gsPort field. To operate the Game Server in verbose mode (i.e. to have the Player requests being printed to the terminal), make use of the flag -v.

3. You can execute the Player by running:

./player [-n gsIP] [-p gsPort]

Both the -n and -p flags are optional. The first overrides the default Game Server IP (localhost, for games running on the same machine) with a custom one. In order to have the executables running on different machines, you need to specify the IP in gsIP (e.g. tejo.tecnico.ulisboa.pt). To change the default port, 58092, as seen in the previous command, specify it in the gsPort field.

4. The available game commands are presented to the Player, when they execute the file, and are as follows:

• sg <PLID> or start <PLID> - starts a new game;
• pl <letter> or play <letter> - submits the letter as a new play;
• gw <word> or guess <word> - submits the word as a guess;
• sb or scoreboard - shows the top 10 scores;
• h or hint - retrieves an image file containing a hint for the word to be guessed;
• st or state - displays the current game state, or the game state of the last game played by the player;
• rev or reveal - reveals the current word (counts as quitting);
• quit - terminates the current game;
• exit - terminates the current game and the player application.