JavaScript

Socket Send/Receive 16-bit Integers

Demonstrates sending and receiving 16-bit integers over a socket connection using either big-endian or little-endian byte ordering. JavaScript

var success = false;

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

var sock = new CkSocket();

// --------------------------------------------------------------------
// This example uses the public TCP echo service at https://tcpbin.com/
// --------------------------------------------------------------------

var useTls = false;
var port = 4242;
var maxWaitMs = 5000;
success = sock.Connect("tcpbin.com",port,useTls,maxWaitMs);
if (success == false) {
    console.log(sock.LastErrorText);
    return;
}

// Wait a max of 2 seconds for a response..
sock.MaxReadIdleMs = 2000;

// Send a 16-bit integer using big-endian byte ordering (also called network byte order)
// 12022 decimal = 2EF6 hex
var value = 12022;
var bigEndian = true;
sock.SendInt16(value,bigEndian);
// Send it again, because we'll read it two different ways..
sock.SendInt16(value,bigEndian);

// The tcpbin.com echo server only echoes after receiving an LF (linefeed char)
sock.SendByte(10);

// Let's see hex values of the 2 bytes sent in network byte order (big-endian)
// (The echo server sends back exactly the bytes received.)
var hexStr = sock.ReceiveNBytesENC(2,"hex");

// In the big-ending byte order, the byte order is most significant byte to least significant,
// therefore we should see the bytes in the order 0x2E 0xF6.
console.log("Expecting big-endian 2EF6");
console.log(hexStr);

// Let's read directly to an integer..
success = sock.ReceiveInt16(bigEndian,true);
console.log("Expecting 12022");
console.log("Received: " + sock.ReceivedInt);

// Consume the LF that gets echoed back..
sock.ReceiveByte(true);

// --------------------------------------------------------------------
// Let's do the same thing, but with little-endian byte ordering.

console.log("----");

// 12022 decimal = 2EF6 hex, but little-endian byte ordering will send the bytes in the order 0xF6 0x2E
value = 12022;
bigEndian = false;
sock.SendInt16(value,bigEndian);
sock.SendInt16(value,bigEndian);
sock.SendByte(10);

hexStr = sock.ReceiveNBytesENC(2,"hex");

console.log("Expecting little-endian F62E");
console.log(hexStr);

success = sock.ReceiveInt16(bigEndian,true);
console.log("Expecting 12022");
console.log("Received: " + sock.ReceivedInt);

// Consume the LF that gets echoed back..
sock.ReceiveByte(true);

sock.Close(1000);

// Output:

// Expecting big-endian 2EF6
// 2EF6
// Expecting 12022
// Received: 12022
// ----
// Expecting little-endian F62E
// F62E
// Expecting 12022
// Received: 12022