Examples

Clients

These HTTP clients submit a GET request to a server specified on the command line, and prints the resulting response. The crawl client asynchronously fetches the document root of the 10,000 top ranked domains, this may be used to evaluate robustness. All asynchronous clients support timeouts.

Description	Source File	Source File (using SSL)
HTTP, synchronous	http_client_sync.cpp	http_client_sync_ssl.cpp
HTTP, asynchronous	http_client_async.cpp	http_client_async_ssl.cpp
HTTP, asynchronous using `net::system_executor`		http_client_async_ssl_system_executor.cpp
HTTP, coroutine	http_client_coro.cpp	http_client_coro_ssl.cpp
WebSocket, C++20 coroutine	http_client_awaitable.cpp	http_client_awaitable_ssl.cpp
HTTP crawl (asynchronous)	http_crawl.cpp
HTTP json_body (synchronous)	example/http/client/body/json_client.cpp
HTTP client for all methods (synchronous)	example/http/client/methods/http_client_methods.cpp

These WebSocket clients connect to a server and send a message, then receive a message and print the response before disconnecting. All asynchronous clients support timeouts.

Description	Source File	Source File (using SSL)
WebSocket, synchronous	websocket_client_sync.cpp	websocket_client_sync_ssl.cpp
WebSocket, asynchronous	websocket_client_async.cpp	websocket_client_async_ssl.cpp
WebSocket, asynchronous using `net::system_executor`		websocket_client_async_ssl_system_executor.cpp
WebSocket, coroutine	websocket_client_coro.cpp	websocket_client_coro_ssl.cpp
WebSocket, C++20 coroutine	websocket_client_awaitable.cpp

Servers

These HTTP servers deliver files from a root directory specified on the command line. All asynchronous servers support timeouts.

Description	Source File	Source File (using SSL)
HTTP, synchronous	http_server_sync.cpp	http_server_sync_ssl.cpp
HTTP, asynchronous	http_server_async.cpp	http_server_async_ssl.cpp
HTTP, coroutine	http_server_coro.cpp	http_server_coro_ssl.cpp
HTTP, stackless coroutine	http_server_stackless.cpp	http_server_stackless_ssl.cpp
HTTP, C++ 20 coroutine	http_server_awaitable.cpp
HTTP, fast (optimized for speed)	http_server_fast.cpp
HTTP, small (optimized for space)	http_server_small.cpp
HTTP, flex (plain + SSL)		http_server_flex.cpp

These WebSocket servers echo back any message received, keeping the session open until the client disconnects. All asynchronous servers support timeouts.

Description	Source File	Source File (using SSL)
WebSocket, synchronous	websocket_server_sync.cpp	websocket_server_sync_ssl.cpp
WebSocket, asynchronous	websocket_server_async.cpp	websocket_server_async_ssl.cpp
WebSocket, coroutine	websocket_server_coro.cpp	websocket_server_coro_ssl.cpp
WebSocket, stackless coroutine	websocket_server_stackless.cpp	websocket_server_stackless_ssl.cpp
WebSocket, C++ 20 coroutine	websocket_server_awaitable.cpp
WebSocket, fast (suited for benchmarks)	websocket_server_fast.cpp

Servers (Advanced)

These servers offer both HTTP and WebSocket services on the same port, and illustrate the implementation of advanced features.

Description	Features	Sources
Advanced	Timeouts Multi-threaded HTTP pipelining Parser-oriented HTTP reading Dual protocols: HTTP and WebSocket Clean exit via SIGINT (CTRL+C) or SIGTERM (kill)	advanced_server.cpp
Advanced, flex (plain + SSL)	Timeouts Multi-threaded HTTP pipelining Parser-oriented HTTP reading Dual protocols: HTTP and WebSocket Flexible ports: plain and SSL on the same port Clean exit via SIGINT (CTRL+C) or SIGTERM (kill)	advanced_server_flex.cpp
Advanced, flex (plain + SSL) with awaitable	Timeouts Multi-threaded HTTP pipelining Parser-oriented HTTP reading Dual protocols: HTTP and WebSocket Flexible ports: plain and SSL on the same port Clean exit via SIGINT (CTRL+C) or SIGTERM (kill) Usage of cancellation_signals	advanced_server_flex_awaitable.cpp
Chat Server, multi-threaded	Multi-threaded Broadcasting Messages Multi-user Chat Server JavaScript Browser Client Parser-oriented HTTP reading Dual protocols: HTTP and WebSocket Clean exit via SIGINT (CTRL+C) or SIGTERM (kill)	chat-multi

Chat Server 🎦

This example demonstrates a websocket chat server, allowing multiple users to connect and participate in live, group messaging. It comes with a tiny front end implemented in JavaScript and HTML5 which runs in any browser. The example is accompanied by a one hour presentation which provides a discussion of networking concepts, followed by in-depth explanation of how the client and server are constructed. This talk was delivered at CppCon 2018. The source code in the Beast example contains improvements to the original program.

Table 1.1. Chat WebSocket Server and JavaScript Client

Component	Features	Sources
Server	C++ Timeouts Multi-threaded Broadcast to multiple peers Dual protocols: HTTP and WebSocket Clean exit via SIGINT (CTRL+C) or SIGTERM (kill)	chat-multi
Client	JavaScript / HTML5 Runs in the browser Delivered by the server Only 60 lines total including UI Completely portable graphics	chat_client.html

Boost C++ Libraries

Clients

Servers

Servers (Advanced)

Chat Server 🎦