Send a 4-byte Length Prefix over a Socket

See more Socket/SSL/TLS Examples

Demonstrates Socket.SendCount, which sends a four-byte length prefix in network byte order. This is typically used to tell the peer how many bytes follow.

import { Socket } from '@chilkat/react-native'

async function chilkatExample() {
  const socket = new Socket();

  // Connect to the server using TLS.
  const bTls = true;
  const maxWaitMs = 5000;
  try {
    await socket.connectAsync('example.com', 5000, bTls, maxWaitMs);
  } catch {
    console.log(socket.lastErrorText);
    return;
  }

  // Send a four-byte length prefix in network byte order.  A common framing pattern is to send the
  // number of bytes in a message before the message itself, so the peer knows exactly how many bytes
  // to read.
  const messageLength = 512;
  try {
    await socket.sendCountAsync(messageLength);
  } catch {
    console.log(socket.lastErrorText);
    return;
  }

  console.log('Length prefix sent.');
}