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Open topic with navigation CAPL Functions » TCP/IP API » TcpOpen

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TcpOpen

Valid for: CANoe DE • CANoe4SW DE

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Function Syntax

  • dword TcpOpen( dword ipv4Address, dword port); // form 1
  • dword TcpOpen( byte ipv6Address[], dword port); // form 2
  • dword TcpOpen( IP_Endpoint localEndpoint ); // form 3

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Method Syntax as Constructor

  • TcpSocket::Open(IP_Endpoint localEndpoint );

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Description

Depending on the address type, the function creates either an IPv4 or IPv6 TCP socket for use in connection-based, message-oriented communications. All parameters may be zero. If the port parameter is non-zero, the socket is implicitly bound to the given port. Otherwise, the socket can be bound later on with IpBind or it will be automatically bound to a free port with TcpConnect. Note: If an address is given but the port is zero no implicit bind is performed. Please use IpBind after opening the socket in this case.

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Parameters

  • ipv4Address: The numerical local IPv4 address to be used with the socket. If set to 0, then the socket is address unspecific (address wildcard).
  • ipv6Address: The local IPv6 address in a 16 byte array. Like in the IPv4 address, an address wildcard can be retrieved using IpGetAddressAsArray(”::”, ipv6AddrArray).
  • port: The port in host-byte order to be used with the socket. If set to 0, then the socket is port unspecific (port wildcard).
  • localEndpoint: Bind the socket to this local endpoint. IP Address can be 0, if the socket should not be bound to an address. Port number can be undefined, if a dynamic port number should be used. Examples:
    • IP_Endpoint(192.168.1.1:4000) – Bind to address and port
    • IP_Endpoint(0.0.0.0:4000) – Bind only to port for IPv4
    • IP_Endpoint([::]:4000) – Bind only to port for IPv6
    • IP_Endpoint(192.168.1.1) – Bind to address and choose a dynamic port

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Return Values

  • INVALID_SOCKET (~0): The function failed. Call IpGetLastError to get a more specific error code.
  • Any other value: A valid socket handle identifying the created socket.

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Example

// ---------------------------------------------------
// start server
// ---------------------------------------------------
void serverStart()
{
  listenSocket = TcpOpen(0, listenPort);
  if (listenSocket != ~0)
  {
    if (TcpListen(listenSocket) == 0)
    {
      // success…
    }
    else
    {
      writeLineEx(1, 3, " [ TcpListen: Error listening on socket. ]");
      TcpClose(listenSocket);
      listenSocket = ~0;
    }
  }
  else
  {
    writeLineEx(1, 3, " [ TcpOpen: Error opening TCP Socket on port %d. (Error %d) ]", listenPort, IpGetLastError());
  }
}
You can find further examples in the Ethernet chat sample configurations Open Folder (only with installed Ethernet option available).