A thin and simple C++ TCP client and server library with an example application.

Currently, both linux and mac are supported.

Simple tcp server-client example application. It is optimized for simplicity and ease of use/read but not for performance. However, I believe tuning its code to suite your needs should be easy in most cases. You can find examples of both server and client under the 'examples' directory. Both the library and the examples are well documented.

The server is thread-safe, and can handle multiple clients at the same time, and remove dead clients resources automatically.

build the examples and static library file:

$ cd tcp_server_client
$ ./build

run the server and client examples: Navigate into the build folder and run in the terminal:

$ cd build

In terminal #1:

$ ./tcp_server

In terminal #2:

$ ./tcp_client

This project is set to use CMake to build both the client example and the server example. In addition, CMake builds a static library file to hold the common code to both server and client.

In order to build the project you can either use the build.sh script:

$ cd tcp_server_client
$ ./build

or build it manually:

$ cd tcp_server_client
$ mkdir build
$ cmake ..
$ make

The build process generate three files: libtcp_client_server.a, tcp_client and tcp_server. The last two are the executables of the examples which can be executed in the terminal.

By default, the CMake configuration builds both server and client. However, you can use flags to build only one of the apps as follows:

To build only the client, disable the server build by replace the cmake .. call by:

cmake -DSERVER_EXAMPLE=OFF ..

And then run the make command as usual.

To build only the server, disable the client build by replace the cmake .. call by:

cmake -DCLIENT_EXAMPLE=OFF ..

And then run the make command as usual.

Navigate into the build folder and run in the terminal:

$ ./tcp_server

You should see a menu output on the screen, we'll get back to that. In a different terminal, run the client:

$ ./tcp_client

You should see a similar menu for the client too. In addition, as mentioned, the client will try to connect to the server right away, so you should also see an output messages on both client and server terminals indicating that the connection succeeded. Now, feel free to play with each of the client/server menus. You can exchange messages b/w client and server, print active clients etc. You can also spawn more clients in other terminals to see how the server handles multiple clients.

After playing with the examples, go into the examples source code and have a look at the main() function to learn how the server and client interacts. The examples are heavily documented. In addition, you can also look at the public functions in tcp_client.h and tcp_server.h to learn what APIs are available.

Both server and client are using the observer design pattern to register and handle events. When registering to an event with a callback, you should make sure that:

• The callback is fast (not doing any heavy lifting tasks) because those callbacks are called from the context of the server or client.
• No server / client function calls are made in those callbacks to avoid possible deadlock.