Dart

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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Dart

import 'package:chilkat/chilkat.dart';

void main() {
  final socket = CkSocket();

  // Connect to the server using TLS.
  final bTls = true;
  final maxWaitMs = 5000;
  try {
    socket.connect('example.com', 5000, bTls, maxWaitMs);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    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.
  final messageLength = socket.receiveCount();
  if (messageLength < 0) {
    print(socket.lastErrorText);
    return;
  }

  print('The peer will send $messageLength bytes.');
}