< .NET IP Multicasting & C++ Example | Main | C# Multicast Program Example >
Chapter 8 Part 24:
Client (and Server) Sockets Communication
What do we have in this chapter 8 Part 24?
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C++ Multicast Program Example (Continue)
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C++ Multicast Program Example (Continue)
Next, add usage() function.
Finally, add the main() code.
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/// <summary> /// This is the main routine which parses the command line and creates the /// multicast socket as given by the command line parameters. The sample /// can either be invoked as a multicast sender or receiver. /// /// To invoke as a multicast receiver: /// multicast.exe /r /i 10.10.10.1 /m 234.6.6.6 /// To invoke as a multicast sender: /// multicast.exe /s /i 10.10.10.99 /m 234.6.6.6 /// </summary> /// <param name="appArguments">Command line arguments</param> int main(array<System::String ^> ^args) { MulticastEndpoint^ mcastEndpoint = gcnew MulticastEndpoint(); String^ textMessage = "Hello Bastard World out there!"; int port = 0, bufferLength = 1024, opCount = 10; bool isSender = true;
// Parse the command line for (int i = 0; i < args->Length; i++) { try { if ((args[i][0] == '-') || (args[i][0] == '/')) { switch (Char::ToLower(args[i][1])) { case 'b': // Address to bind multicast socket to mcastEndpoint->bindAddress = IPAddress::Parse(args[++i]); break; case 'c': // How many times to send or receive opCount = Convert::ToInt32(args[++i]->ToString()); break; case 'i': // Local interface to join group(s) on mcastEndpoint->localInterfaceList->Add(IPAddress::Parse(args[++i])); break; case 'm': // Multicast group to join mcastEndpoint->multicastJoinList->Add(IPAddress::Parse(args[++i])); break; case 'p': // Port number to bind to or send to port = Convert::ToInt32(args[++i]->ToString()); break; case 'r': // Application invoked as receiver isSender = false; break; case 's': // Application invoked as sender isSender = true; break; case 't': // Text message to send textMessage = args[++i]; break; case 'x': // Length of send/receive buffer bufferLength = Convert::ToInt32(args[++i]->ToString()); break; default: usage(); return 0; } } } catch(Exception^ err) { Console::WriteLine("Error: " + err->Message); usage(); return 0; } }
// Make sure user specified at least on multicast group and interface to join if ((mcastEndpoint->multicastJoinList->Count == 0) || (mcastEndpoint->localInterfaceList->Count == 0)) { Console::WriteLine("Please specify a multicast group and interface to join on!"); usage(); return 0; }
// Now, create the multicast socket Console::WriteLine("Creating the multicast socket..."); try { if (isSender == true) { // For the sender, we don't care what the local port the socket is bound to mcastEndpoint->Create( 0, // If the sender we don't care what local port we bind to bufferLength ); } else { mcastEndpoint->Create(port, bufferLength); }
if (isSender == true) { IPEndPoint^ destinationGroup = gcnew IPEndPoint((IPAddress^)mcastEndpoint->multicastJoinList[0], port); int rc;
// Set the send interface for all outgoing multicast packets Console::WriteLine("Setting the send interface for all outgoing multicast packets..."); mcastEndpoint->SetSendInterface((IPAddress^)mcastEndpoint->localInterfaceList[0]); mcastEndpoint->FormatBuffer(textMessage);
// Send the message the requested number of times Console::WriteLine("Sending the message the requested number of times..."); for (int i = 0; i < opCount; i++) { try { rc = mcastEndpoint->mcastSocket->SendTo(mcastEndpoint->dataBuffer, destinationGroup); Console::Write("Multicast SendTo() is OK. "); Console::WriteLine("Sent {0} bytes to {1}", rc, destinationGroup->ToString()); } catch (SocketException^ err) { Console::WriteLine("Multiast SendTo() failed: " + err->Message); } } } else { IPEndPoint^ senderEndPoint = gcnew IPEndPoint((IPAddress^)mcastEndpoint->localInterfaceList[0], 0); EndPoint^ castSenderEndPoint = (EndPoint^)senderEndPoint; int rc;
for (int i = 0; i < opCount; i++) { try { rc = mcastEndpoint->mcastSocket->ReceiveFrom(mcastEndpoint->dataBuffer, castSenderEndPoint); Console::Write("Multicast ReceiveFrom() is OK..."); // Setting to an instance of an object before using it senderEndPoint = (IPEndPoint^)castSenderEndPoint;
Console::WriteLine("Received {0} bytes from {1}: '{2}'\n", rc, senderEndPoint->ToString(), Text::Encoding::ASCII->GetString(mcastEndpoint->dataBuffer, 0, rc) ); } catch (SocketException^ err) { Console::WriteLine("Multicast ReceiveFrom() failed: " + err->Message); } } } // Drop membership to groups. This isn't required in this sample as closing the socket // will implicitly leave all groups joined, but it's a good practice. mcastEndpoint->LeaveGroups(); } catch(Exception^ err) { Console::WriteLine("An error occurred creating the multicast socket: " + err->Message); } finally { if (mcastEndpoint->mcastSocket != nullptr) { Console::WriteLine("Closing the multicast socket..."); mcastEndpoint->mcastSocket->Close(); } mcastEndpoint = nullptr; } return 0; } |
Build the project and make sure there is no error. Run the project. Any error will be thrown by the exception handlers. The following is the sample output.
The following sample output shows the program as a receiver.
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The following sample output shows the program as a sender.
The following are sample outputs show the sender and receiver. This program example was tested on a simple private network with two computers connected using the peer-to-peer cable (cross cable). You may want to test on the real network with more receivers that will resemble the chat system. Firstly, we run the receiver.
Then, we run the sender.
The following is the receiver output screenshot when the communication was completed.
