(C) Transfer a File using Sockets (TLS or non-TLS)

Demonstrates how to two programs, one a socket writer and the other a socket reader, can transfer a file. The connection can be TLS or a regular non-encrypted TCP connection.

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#include <C_CkBinData.h>
#include <C_CkSocket.h>

void ChilkatSample(void)
    {
    HCkBinData bdToSend;
    BOOL success;
    HCkSocket sndSock;
    BOOL bUseTls;
    int port;
    int maxWaitMs;
    int numBytes;
    BOOL bBigEndian;
    HCkSocket listenSock;
    HCkSocket rcvSock;
    int numBytesComing;
    HCkBinData bdReceived;
    int maxWaitMs;

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // On the sending side, we'll load the file into a BinData object and send.
    // On the receiving side, we'll read from the socket connection into a BinData, and save to a file.
    // This example assumes the file is not crazy-large, and that the entire contents
    // can fit into memory.  
    // (If the file is too large for memory, there are other ways to send. It just involves streaming or 
    // sending the file chunk-by-chunk..)

    // This section of code is for the sender.
    bdToSend = CkBinData_Create();
    success = CkBinData_LoadFile(bdToSend,"somePath/someFile.dat");
    // Assume success for the example...

    sndSock = CkSocket_Create();
    bUseTls = TRUE;
    port = 5555;
    maxWaitMs = 5000;
    success = CkSocket_Connect(sndSock,"some_domain_or_ip.com",port,bUseTls,maxWaitMs);
    // Assume success for the example...

    // Tell the receiver how many bytes are coming.
    numBytes = CkBinData_getNumBytes(bdToSend);
    bBigEndian = TRUE;
    success = CkSocket_SendInt32(sndSock,numBytes,bBigEndian);

    // Send the file data (sends the entire contents of bdToSend).
    success = CkSocket_SendBd(sndSock,bdToSend,0,0);

    // Get an acknowledgement.
    success = CkSocket_ReceiveInt32(sndSock,bBigEndian);
    if (success != TRUE) {
        printf("%s\n",CkSocket_lastErrorText(sndSock));
        CkBinData_Dispose(bdToSend);
        CkSocket_Dispose(sndSock);
        return;
    }

    // Did the receiver get the correct number of bytes?
    if (CkSocket_getReceivedInt(sndSock) != numBytes) {
        printf("The receiver did not acknowledge with the correct number of bytes.\n");
        CkBinData_Dispose(bdToSend);
        CkSocket_Dispose(sndSock);
        return;
    }

    printf("File sent!\n");

    // ------------------------------------------------------------------------------------
    // The code below is for the receiving side (running on some other computer..)

    listenSock = CkSocket_Create();

    success = CkSocket_BindAndListen(listenSock,5555,25);
    if (success != TRUE) {
        printf("%s\n",CkSocket_lastErrorText(listenSock));
        CkBinData_Dispose(bdToSend);
        CkSocket_Dispose(sndSock);
        CkSocket_Dispose(listenSock);
        return;
    }

    // Get the next incoming connection
    // Wait a maximum of 20 seconds (20000 millisec)

    rcvSock = CkSocket_AcceptNextConnection(listenSock,20000);
    if (CkSocket_getLastMethodSuccess(listenSock) == FALSE) {
        printf("%s\n",CkSocket_lastErrorText(listenSock));
        CkBinData_Dispose(bdToSend);
        CkSocket_Dispose(sndSock);
        CkSocket_Dispose(listenSock);
        return;
    }

    // The sender will first send the big-endian integer for the number of bytes
    // that are forthcoming..
    success = CkSocket_ReceiveInt32(rcvSock,bBigEndian);
    if (success != TRUE) {
        printf("%s\n",CkSocket_lastErrorText(rcvSock));
        CkSocket_Dispose(rcvSock);
        CkBinData_Dispose(bdToSend);
        CkSocket_Dispose(sndSock);
        CkSocket_Dispose(listenSock);
        return;
    }

    numBytesComing = CkSocket_getReceivedInt(rcvSock);

    // Receive that many bytes..
    bdReceived = CkBinData_Create();
    success = CkSocket_ReceiveBdN(rcvSock,numBytesComing,bdReceived);
    if (success != TRUE) {
        printf("%s\n",CkSocket_lastErrorText(rcvSock));
        CkSocket_Dispose(rcvSock);
        CkBinData_Dispose(bdToSend);
        CkSocket_Dispose(sndSock);
        CkSocket_Dispose(listenSock);
        CkBinData_Dispose(bdReceived);
        return;
    }

    // Acknowledge the sender by sending back the number of bytes we received.
    success = CkSocket_SendInt32(rcvSock,CkBinData_getNumBytes(bdReceived),bBigEndian);

    // Close the connection.
    maxWaitMs = 20;
    CkSocket_Close(rcvSock,maxWaitMs);
    CkSocket_Dispose(rcvSock);

    // Save the received data to a file.
    success = CkBinData_WriteFile(bdReceived,"somePath/someFile.dat");
    // Assume success for the example...

    printf("File received!\n");


    CkBinData_Dispose(bdToSend);
    CkSocket_Dispose(sndSock);
    CkSocket_Dispose(listenSock);
    CkBinData_Dispose(bdReceived);

    }