More improvements in the examples.

examples/basic4.cpp

@@ -0,0 +1,75 @@
+/* Copyright (c) 2019 - 2021 Marcelo Zimbres Silva (mzimbres at gmail dot com)
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+#include <iostream>
+#include <chrono>
+
+#include <aedis/aedis.hpp>
+
+#include "utils.ipp"
+
+using namespace aedis;
+
+/** In previous examples we sent the command we were interested in and
+ *  quit (closed) the connection. In this example we send a
+ *  subscription to a channel and start reading for message
+ *  indefinitely.
+ *
+ *  Notice we store the id of the connection as seem by redis to be
+ *  able to identify it.
+ *
+ *  After starting the example you can send messages with the
+ *  redis-client like this
+ *
+ *  $ redis-cli -3
+ *  127.0.0.1:6379> PUBLISH channel1 mmmm
+ *  (integer) 3
+ *  127.0.0.1:6379>
+ *
+ *  The messages will then appear on the terminal you are running the
+ *  example.
+ */
+net::awaitable<void> subscriber()
+{
+   resp3::request req;
+   req.push(command::hello, "3");
+   req.push(command::subscribe, "channel1", "channel2");
+
+   auto socket = co_await make_connection("127.0.0.1", "6379");
+   co_await async_write(socket, req);
+
+   std::string buffer;
+   resp3::response resp;
+
+   // Reads the response to the hello command.
+   co_await async_read(socket, buffer, resp);
+
+   // Saves the id of this connection.
+   auto const id = resp.raw().at(8).data;
+
+   // Reads the response to the subscribe command.
+   co_await async_read(socket, buffer, resp);
+
+   // Loops to receive server pushes.
+   for (;;) {
+      resp.clear();
+      co_await async_read(socket, buffer, resp);
+
+      std::cout
+	 << "Subscriber " << id << ":\n"
+	 << resp << std::endl;
+   }
+}
+
+int main()
+{
+   net::io_context ioc;
+   co_spawn(ioc, subscriber(), net::detached);
+   co_spawn(ioc, subscriber(), net::detached);
+   co_spawn(ioc, subscriber(), net::detached);
+   ioc.run();
+}