(PHP ActiveX) 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.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows Note: The php_com_dotnet.dll may need to be enabled inside of php.ini.

<?php

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

// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.Socket')
$sock = new COM("Chilkat.Socket");

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

$useTls = 0;
$port = 4242;
$maxWaitMs = 5000;
$success = $sock->Connect('tcpbin.com',$port,$useTls,$maxWaitMs);
if ($success == 0) {
    print $sock->LastErrorText . "\n";
    exit;
}

// 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
$value = 12022;
$bigEndian = 1;
$sock->SendInt16($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.)
$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.
print 'Expecting big-endian 2EF6' . "\n";
print $hexStr . "\n";

// Let's read directly to an integer..
$success = $sock->ReceiveInt16($bigEndian,1);
print 'Expecting 12022' . "\n";
print 'Received: ' . $sock->ReceivedInt . "\n";

// Consume the LF that gets echoed back..
$sock->ReceiveByte(1);

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

print '----' . "\n";

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

$hexStr = $sock->receiveNBytesENC(2,'hex');

print 'Expecting little-endian F62E' . "\n";
print $hexStr . "\n";

$success = $sock->ReceiveInt16($bigEndian,1);
print 'Expecting 12022' . "\n";
print 'Received: ' . $sock->ReceivedInt . "\n";

// Consume the LF that gets echoed back..
$sock->ReceiveByte(1);

$sock->Close(1000);

// Output:

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

?>