websocket-client

C++ Wrapper for https://libwebsockets.org/

Very straightforward to use, make sure you compile libwebsockets first, please note that I'm using the static lib libwebsockets.a and you might need to adjust the the path or use the shared library, so adjust accordingly in your cmake file.

#include <libwebsockets.h>
#include "src/libs/callback.h"
#include "src/libs/websocket_client.h"

class websocket : public websocket_client, public client_callback_t {
    bool run_ = true;
public:
    websocket() : websocket_client(this, "ws-feed.pro.coinbase.com") {}

    [[nodiscard]] bool working() const noexcept { return run_; }

    void on_connected() override {
        lwsl_user("client connected\n");
        std::string msg = R"({ "type": "subscribe", "product_ids": [ "ETH-USD", "ETH-EUR" ], "channels": [ "level2", "heartbeat", { "name": "ticker", "product_ids": [ "ETH-BTC", "ETH-USD" ] } ] })";
        send(msg.data(), msg.size());
    }

    void on_disconnected() override {
        lwsl_user("client disconnected\n");
    }

    void on_error(const char *msg, size_t len) override {
        lwsl_user("client error\n");
    }

    void on_data(const char *data, size_t len, size_t remaining) override {
        std::string msg(data, len);
        lwsl_user("data from server: %s\n", msg.c_str());
    }
};

int main() {
    lws_set_log_level(LLL_USER | LLL_ERR | LLL_WARN | LLL_NOTICE, nullptr);
    websocket client;
    client.connect();
    while (client.working()) {
    }
    return 0;
}

Testing

cmake .
make
./websocket-client

[2021/04/04 20:35:07:4351] N: LWS: 4.1.99-v4.1.0-361-g010c8c86, loglevel 1031
[2021/04/04 20:35:07:4352] N: NET CLI SRV H1 H2 WS ConMon IPv6-absent
[2021/04/04 20:35:07:4355] N:  ++ [wsi|0|pipe] (1)
[2021/04/04 20:35:07:4356] N:  ++ [vh|0|netlink] (1)
[2021/04/04 20:35:07:4365] N:  ++ [vh|1|default||-1] (2)
[2021/04/04 20:35:07:4368] U: Connecting to ws-feed.pro.coinbase.com:443/
[2021/04/04 20:35:07:4368] N:  ++ [wsicli|0|WS/h1/ws-feed.pro.coinbase.com] (1)
[2021/04/04 20:35:07:5492] U: client connected
[2021/04/04 20:35:07:5689] U: data from server: {"type":"subscriptions","channels":[{"name":"ticker","product_ids":["ETH-BTC","ETH-USD","ETH-EUR"]},{"name":"level2","product_ids":["ETH-USD","ETH-EUR"]},{"name":"heartbeat","product_ids":["ETH-USD","ETH-EUR"]}]}
[2021/04/04 20:35:07:5689] U: data from server: {"type":"ticker","sequence":3137155619,"product_id":"ETH-BTC","price":"0.03565","open_24h":"0.03533","volume_24h":"13506.99212892","low_24h":"0.03492","high_24h":"0.03596","volume_30d":"631591.13023732","best_bid":"0.03564","best_ask...
[2021/04/04 20:35:07:5938] U: data from server: {"type":"snapshot","product_id":"ETH-EUR","asks":[["1763.63","1.02938083"],["1763.64","4.82847755"],["1763.81","3.00000000"],["1763.82","7.24271632"],["1763.87","0.64200000"],["1764.03","2.00000000"],["1764.04","3.29819290"],["1764.1...
[2021/04/04 20:35:07:5939] U: data from server: ,["1806.07","0.11333117"],["1806.09","268.43000000"],["1806.85","0.05170625"],["1806.95","0.50000000"],["1807.00","0.92146852"],["1807.22","0.01000000"],["1807.39","0.09938438"],["1808.00","0.69795682"],["1808.09","0.08519265"],["180...