code cleanup, moved param processing to separate function

example/simple_chat_demo.cpp

@@ -14,9 +14,11 @@
  * 
  * Sample make file:
  * g++ -std=c++17 -Wall -Werror \
- * -I ../include -I ../include/net_ip/ -I ~/Projects/utility-rack/include/ \
- * -I ~/Projects/asio/asio/include \
- * simple_chat_deo.cpp -lpthread
+ * -I ../include -I ../include/net_ip/ 
+ * -I ~/Projects/utility-rack/include/ \
+ * -I ~/Projects/asio-1.12.2/include \
+ * -I ~/Projects/boost_1_69_0/ \
+ * simple_chat_deo.cpp -lpthread -o chat
  * 
  * BUGS:
  * - leaks memory like a sieve. Under investigation.
@@ -47,7 +49,7 @@ using endpoint = asio::ip::tcp::endpoint;
 /** How to use @c chops-net-ip for a simple text send/receive network connection
  * over a local loop.
  * 
- * 1. Write message handlers for the @c tcp_connector and @c tcp_acceptor.
+ * 1. Write message handler for the @c tcp_connector and @c tcp_acceptor.
  * 
  * The @c tcp_connector_message_handler receives text from a @c tcp_acceptor
  * (in-bound messages). In this demo, the handler prints the text to stdout,
@@ -108,13 +110,9 @@ const std::string help = "-h";
 const std::string param_connect = "-connect";
 const std::string param_accept = "-accept";
 
-int main(int argc, char* argv[]) {
- const char* ip_addr = LOCAL_LOOP.c_str();
- const char* port = PORT.c_str();
- std::string param;
-
- //std::cout << "argc: " << argc << std::endl;
-
+// process command line args, set ip_addr, port, param as needed
+bool process_args(int argc, char* argv[], const char*& ip_addr, 
+ const char*& port, std::string& param) {
  if (argc < 2 || argc > 4) {
  std::cout << "incorrect parameter count\n";
  std::cout << usage << std::endl;
@@ -123,13 +121,14 @@ int main(int argc, char* argv[]) {
 
  if (argv[1] == help) {
  std::cout << usage << std::endl;
- return EXIT_SUCCESS;
- } else if (param_connect == argv[1]) {
+ return EXIT_FAILURE;
+ } else if (argv[1] == param_connect) {
  param = param_connect;
  } else if (argv[1] == param_accept) {
  param = param_accept;
  } else {
- std::cout << "incorrect first parameter: must be [-h | -connect | -accept]" << std::endl;
+ std::cout << "incorrect first parameter: ";
+ std::cout << "must be [-h | -connect | -accept]" << std::endl;
  std::cout << usage << std::endl;
  return EXIT_FAILURE;
  }
@@ -141,17 +140,21 @@ int main(int argc, char* argv[]) {
  port = argv[3];
  }
 
- std::cout << "2-way chat demo" << std::endl;
- std::cout << "IP address: " << ip_addr << "; port: " << port << std::endl;
- std::cout << "connection type: " << param << std::endl;
- std::cout << "enter -h for usage" << std::endl;
- std::cout << "enter text message at the prompt" << std::endl;
- std::cout << "enter \'quit\' to exit" << std::endl << std::endl;
+ return EXIT_SUCCESS;
+}
 
+int main(int argc, char* argv[]) {
+ const char* ip_addr = LOCAL_LOOP.c_str();
+ const char* port = PORT.c_str();
+ std::string param;
+
+ if (process_args(argc, argv, ip_addr, port, param) == EXIT_FAILURE) {
+ return EXIT_FAILURE;
+ }
 
  /* lambda callbacks */
- // message handler for @c tcp_connector @c network_entity
- auto msg_hndlr_connect = [] (const_buf buf, io_interface iof, endpoint ep)
+ // message handler for @c network_entity
+ auto msg_hndlr = [] (const_buf buf, io_interface iof, endpoint ep)
  {
  // receive data from acceptor, display to user
  std::string s (static_cast<const char*> (buf.data()), buf.size());
@@ -161,24 +164,17 @@ int main(int argc, char* argv[]) {
  return s == "QUIT\n" ? false : true;
  };
 
- // io state change handlers
- tcp_io_interface tcp_connect_iof; // used to send text data
+ // io state change handler
+ tcp_io_interface tcp_iof; // used to send text data
  // handler for @c tcp_connector
- auto io_state_chng_connect = [&tcp_connect_iof, msg_hndlr_connect] 
+ auto io_state_chng_hndlr = [&tcp_iof, msg_hndlr] 
  (io_interface iof, std::size_t n, bool flag)
  {
- iof.start_io("\n", msg_hndlr_connect);
+ iof.start_io("\n", msg_hndlr);
  // return iof to main
- tcp_connect_iof = iof;
+ tcp_iof = iof;
  };
 
- // // handler for @c tcp_acceptor
- // auto io_state_chng_accept = [msg_hndlr_accept]
- // (io_interface iof, std::size_t n, bool flag)
- // {
- // iof.start_io("\n", msg_hndlr_accept);
- // };
-
  // error handler
  auto err_func = [] (io_interface iof, std::error_code err) 
  { 
@@ -199,22 +195,26 @@ int main(int argc, char* argv[]) {
  chops::net::net_ip chat(wk.get_io_context());
  if (param == param_connect) {
  // make @c tcp_connector, receive @c network_entity
+
  auto net_entity = chat.make_tcp_connector(port, ip_addr);
  assert(net_entity.is_valid());
  // start network entity, emplace handlers
- net_entity.start(io_state_chng_connect, err_func);
+ net_entity.start(io_state_chng_hndlr, err_func);
  } else if (param == param_accept){
+
  // make @ tcp_acceptor, receive @c tcp_acceptor_network_entity
  auto net_entity = chat.make_tcp_acceptor(port, ip_addr);
  assert(net_entity.is_valid());
  // start network entity, emplace handlers
- net_entity.start(io_state_chng_connect, err_func);
+ net_entity.start(io_state_chng_hndlr, err_func);
  }
 
- // pause to let both sides connect
- std::this_thread::sleep_for(std::chrono::milliseconds(4000));
-
- assert(tcp_connect_iof.is_valid()); // fails without a pause
+ std::cout << "2-way chat demo" << std::endl;
+ std::cout << "enter -h at command line for usage" << std::endl;
+ std::cout << "IP address: " << ip_addr << "; port: " << port << std::endl;
+ std::cout << "connection type: " << param << std::endl;
+ std::cout << "enter text message at the prompt" << std::endl;
+ std::cout << "enter \'quit\' to exit" << std::endl << std::endl;
 
  // get std::string from user
  // send as c-string over network connection
@@ -224,7 +224,8 @@ int main(int argc, char* argv[]) {
  std::getline (std::cin, s);
  s += "\n"; // needed for deliminator
  // send c-string from @c tcp_connector to @c tcp_acceptor
- tcp_connect_iof.send(s.c_str(), s.size() + 1);
+ assert(tcp_iof.is_valid());
+ tcp_iof.send(s.c_str(), s.size() + 1);
 
  std::this_thread::sleep_for(std::chrono::milliseconds(100));
  }