C++

Receive a 4-byte Length Prefix from a Socket

Demonstrates Socket.ReceiveCount, which reads a four-byte length prefix as a signed 32-bit integer. A return value of -1 indicates failure.

Background. Reading the length prefix first tells the application exactly how many bytes to read for the message body, which is a reliable way to know when a full message has arrived.

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C++

#include <CkSocket.h>

void ChilkatSample(void)
    {
    bool success = false;

    CkSocket socket;

    //  Connect to the server using TLS.
    bool bTls = true;
    int maxWaitMs = 5000;
    success = socket.Connect("example.com",5000,bTls,maxWaitMs);
    if (success == false) {
        std::cout << socket.lastErrorText() << "\r\n";
        return;
    }

    //  Read a four-byte length prefix as a signed 32-bit integer (network byte order by default).  A
    //  return value of -1 indicates failure.
    int messageLength = socket.ReceiveCount();
    if (messageLength < 0) {
        std::cout << socket.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "The peer will send " << messageLength << " bytes." << "\r\n";
    }