TcpStatus

Use TcpStatus to obtain the current status of a TCP connection. Your program sets the Connection field of the ConnectionInfo record to the number of the connection whose status you want. Figure 1 shows an example of TcpStatus.

Figure 1. TcpStatus example

   procedure TcpStatus
            (
        var    ConnectionInfo: StatusInfoType;
        var    ReturnCode: integer
            );
            external;

Parameter

Description

ConnectionInfo

If ReturnCode is OK, the following fields are returned.

OpenAttemptTimeout: If the connection is in the process of being opened (including a passive open), this field is set to the number of seconds remaining before the open is terminated if it has not completed. Otherwise, it is set to WAITforever.
BytesToRead: The number of bytes of incoming data queued for your program (waiting for TcpReceive, TcpFReceive, or TcpWaitReceive).
UnackedBytes: The number of bytes sent by your program but not yet sent to the foreign TCP, or the number of bytes sent to the foreign TCP, but not yet acknowledged.
ConnectionState: The current connection state.
LocalSocket: The local socket, consisting of a local address and a local port.
ForeignSocket: The foreign socket, consisting of a foreign address and a foreign port.

ReturnCode

Indicates the success or failure of the call. Possible return values are:

OK
NOsuchCONNECTION
NOTyetBEGUN
TCPipSHUTDOWN
REMOTEreset
SOFTWAREerror

For a description of Pascal return codes, see Table 1.

Note: Your program cannot monitor connection state changes exclusively through polling with TcpStatus. It must receive CONNECTIONstateCHANGED notifications through GetNextNote for the TCP interface to work properly.