< Raw Socket & IPv4, ICMP, TCP Listeners | Main | VB .NET TcpListener & C++ .NET TCP Client Examples >
Chapter 8 Part 28:
Client (and Server) Sockets Communication
What do we have in this chapter 8 Part 28?
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C++ TcpListener Program Example
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C# TcpListener Program Example
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C++ TcpListener Program Example
Create a new CLR console application project and you might want to use TcpListenerSampleCP as the name.
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Add the following code.
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// TcpListenerSampleCP.cpp : main project file. #include "stdafx.h"
using namespace System; using namespace System::Net; using namespace System::Net::Sockets;
static void usage() { Console::WriteLine("Usage: Executable_file_name [-l address] [-p port] [-x size]"); Console::WriteLine("Available options:"); Console::WriteLine(" -l address Local address for TCP server to listen on"); Console::WriteLine(" -p port Local port for TCP server to listen on"); Console::WriteLine(" -x size Size of send and receive buffers"); Console::WriteLine(); }
int main(array<System::String ^> ^args) { IPAddress^ listenInterface = IPAddress::Any; unsigned short listenPort = 5150; int bufferSize = 4096;
// Parse the command line if(args->Length !=0) { for (int i = 0; i < args->Length; i++) { try { if ((args[i][0] == '-') || (args[i][0] == '/')) { switch (Char::ToLower(args[i][1])) { case 'l': // Local interface server should listen on listenInterface = IPAddress::Parse(args[++i]); break;
case 'p': // Port number for the destination listenPort = Convert::ToUInt16(args[++i]); break;
case 'x': // Size of the send and receive buffers bufferSize = Convert::ToInt32(args[++i]); break;
default: usage(); return 0; } } } catch(Exception^ err) { Console::WriteLine("Error: {0}", err->Message); usage(); return 0; } } } else { usage(); return 0; }
TcpListener^ tcpServer = nullptr; TcpClient^ tcpClient = nullptr; NetworkStream^ tcpStream = nullptr; array<Byte>^ sendBuffer = gcnew array<Byte>(bufferSize); array<Byte>^ receiveBuffer = gcnew array<Byte>(bufferSize) ; array<Byte>^ byteCount; int bytesToRead = 0, nextReadCount, rc;
// Initialize the send buffer Console::WriteLine("TCP Listener: Initializing the send buffer..."); for (int i = 0; i < sendBuffer->Length; i++) sendBuffer[i] = (Byte)'Y';
try { // Create the TCP server Console::WriteLine("TCP Listener: Creating the TCP server..."); tcpServer = gcnew TcpListener(listenInterface, (int)listenPort);
Console::WriteLine("TCP Listener: TcpListener created on address {0} and port {1}", listenInterface->ToString(), listenPort );
// Start listening for connections Console::WriteLine("TCP Listener: Start listening for connections..."); tcpServer->Start();
// Wait for a client connection Console::WriteLine("TCP Listener: Waiting for a client connection..."); tcpClient = tcpServer->AcceptTcpClient();
// Get the NetworkStream so we can do Read and Write on the client connection Console::WriteLine("TCP Listener: Getting the NetworkStream for reading/writing client connection..."); tcpStream = tcpClient->GetStream();
byteCount = BitConverter::GetBytes(bytesToRead);
// First read the number of bytes the client is sending Console::WriteLine("TCP Listener: Reading the number of bytes client sent..."); tcpStream->Read(byteCount, 0, byteCount->Length);
bytesToRead = BitConverter::ToInt32(byteCount, 0);
// Receive the data Console::WriteLine("TCP Listener: Receiving, reading & displaying the data..."); while (bytesToRead > 0) { // Make sure we don't read beyond what the first message indicates // This is important if the client is sending multiple "messages" -- // but in this sample it sends only one if (bytesToRead < receiveBuffer->Length) nextReadCount = bytesToRead; else nextReadCount = receiveBuffer->Length;
// Read some data rc = tcpStream->Read(receiveBuffer, 0, nextReadCount);
// Display what we read String^ readText = Text::Encoding::ASCII->GetString(receiveBuffer, 0, rc); Console::WriteLine("TCP Listener: Received: {0}", readText); bytesToRead -= rc; }
// First send the number of bytes the server is responding with Console::WriteLine("TCP Listener: Sending the number of bytes the server is responding with..."); byteCount = BitConverter::GetBytes(sendBuffer->Length); tcpStream->Write(byteCount, 0, byteCount->Length);
// Send the actual data Console::WriteLine("TCP Listener: Sending the actual data..."); tcpStream->Write(sendBuffer, 0, sendBuffer->Length);
// Close up the client Console::WriteLine("TCP Listener: Closing client tcp stream..."); tcpStream->Close(); tcpStream = nullptr; tcpClient->Close(); tcpClient = nullptr; } catch (SocketException^ err) { // Exceptions on the TcpListener are caught here Console::WriteLine("TCP Listener: Socket error occurred - {0}", err->Message); } catch (IO::IOException^ err) { // Exceptions on the NetworkStream are caught here Console::WriteLine("TCP Listener: I/O error: {0}", err->Message); } finally { // Close any remaining open resources if (tcpServer != nullptr) tcpServer->Stop(); if (tcpStream != nullptr) tcpStream->Close(); if (tcpClient != nullptr) tcpClient->Close(); } return 0; } |
Next, build the project and make sure there is no error that can be seen in the Output window if any. Then, run the project. Any error will be thrown by the exception handlers. The following is the sample output.
Testing the tcp listener with the tcp client. In this case we use the TcpClientSampleCP program as a client. Firstly, we run the listener (both executables have been copied to the C:\).
Next, we run the client.
The following is the tcp listener screenshot after the communication was completed.
Well, you may want to test this program on real network with the listener and the client run on different hosts and try using the available options.
C# TcpListener Program Example
Create a new console application project and you might want to use TcpListenerSampleCS as the name.
Next, rename the class to SimpleTcpListener by renaming the source file name.
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Add/edit the following using directives at the top of the file.
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using System; using System.Net; using System.Net.Sockets; |
Next, add the usage() method and its code.
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static public void usage() { Console.WriteLine("Usage: Executable_file_name [-l address] [-p port] [-x size]"); Console.WriteLine("Available options:"); Console.WriteLine(" -l address Local address for TCP server to listen on"); Console.WriteLine(" -p port Local port for TCP server to listen on"); Console.WriteLine(" -x size Size of send and receive buffers"); Console.WriteLine(); } |
Then, add the Main() code.
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/// <param name="args">Command line arguments</param> static void Main(string[] args) { IPAddress listenInterface = IPAddress.Any; ushort listenPort = 5150; int bufferSize = 4096;
usage();
// 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 'l': // Local interface server should listen on listenInterface = IPAddress.Parse(args[++i]); break; case 'p': // Port number for the destination listenPort = System.Convert.ToUInt16(args[++i]); break; case 'x': // Size of the send and receive buffers bufferSize = System.Convert.ToInt32(args[++i]); break; default: usage(); return; } } } catch { usage(); return; } }
TcpListener tcpServer = null; TcpClient tcpClient = null; NetworkStream tcpStream = null; byte[ ] sendBuffer = new byte[bufferSize], receiveBuffer = new byte[bufferSize], byteCount; int bytesToRead = 0, nextReadCount, rc;
// Initialize the send buffer for (int i = 0; i < sendBuffer.Length; i++) sendBuffer[i] = (byte)'Y';
try { // Create the TCP server Console.WriteLine("TCP Listener: Creating the TCP server..."); tcpServer = new TcpListener(listenInterface, (int)listenPort); Console.WriteLine("TCP Listener: TcpListener created on address {0} and port {1}", listenInterface.ToString(), listenPort );
// Start listening for connections Console.WriteLine("TCP Listener: Start listening for connections..."); tcpServer.Start();
// Wait for a client connection Console.WriteLine("TCP Listener: Waiting for a client connection..."); tcpClient = tcpServer.AcceptTcpClient();
// Get the NetworkStream so we can do Read and Write on the client connection Console.WriteLine("TCP Listener: Getting the NetworkStream for reading/writing client connection..."); tcpStream = tcpClient.GetStream();
byteCount = BitConverter.GetBytes(bytesToRead);
// First read the number of bytes the client is sending Console.WriteLine("TCP Listener: Reading the number of bytes client sent..."); tcpStream.Read(byteCount, 0, byteCount.Length);
bytesToRead = BitConverter.ToInt32(byteCount, 0);
// Receive the data Console.WriteLine("TCP Listener: Receiving, reading & displaying the data..."); while (bytesToRead > 0) { // Make sure we don't read beyond what the first message indicates // This is important if the client is sending multiple "messages" -- // but in this sample it sends only one if (bytesToRead < receiveBuffer.Length) nextReadCount = bytesToRead; else nextReadCount = receiveBuffer.Length;
// Read some data rc = tcpStream.Read(receiveBuffer, 0, nextReadCount);
// Display what we read string readText = System.Text.Encoding.ASCII.GetString(receiveBuffer, 0, rc); Console.WriteLine("TCP Listener: Received: {0}", readText); bytesToRead -= rc; }
// First send the number of bytes the server is responding with Console.WriteLine("TCP Listener: Sending the number of bytes the server is responding with..."); byteCount = BitConverter.GetBytes(sendBuffer.Length); tcpStream.Write(byteCount, 0, byteCount.Length);
// Send the actual data Console.WriteLine("TCP Listener: Sending the actual data..."); tcpStream.Write(sendBuffer, 0, sendBuffer.Length);
// Close up the client Console.WriteLine("TCP Listener: Closing client tcp stream..."); tcpStream.Close(); tcpStream = null; tcpClient.Close(); tcpClient = null; } catch (SocketException err) { // Exceptions on the TcpListener are caught here Console.WriteLine("TCP Listener: Socket error occurred: {0}", err.Message); } catch (System.IO.IOException err) { // Exceptions on the NetworkStream are caught here Console.WriteLine("TCP Listener: I/O error: {0}", err.Message); } finally { // Close any remaining open resources if (tcpServer != null) tcpServer.Stop(); if (tcpStream != null) tcpStream.Close(); if (tcpClient != null) tcpClient.Close(); } } |
Next, build the project and make sure there is no error that can be seen in the Output window if any.
Then, run the project. Any error will be thrown by the exception handlers.
The following is the sample output.
Testing the tcp listener with the tcp client. In this case we use the TcpClientSampleCS program as a client. Firstly, we run the listener (both executables have been copied to the C:\).
Next, we run the client.
The following is the tcp listener screenshot after the communication was completed.
Well, you may want to test this program on real network with the listener and the client run on different hosts and try using the available options.