PHP

Send a 4-byte Length Prefix over a Socket

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.

Background. A length-prefixed framing scheme sends the byte count of a message before the message body, so the receiver knows exactly how many bytes to read with a counted receive.

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Chilkat2 PHP

<?php

use Chilkat2\Socket;

$socket = new Socket();

// Connect to the server using TLS.
$bTls = true;
$maxWaitMs = 5000;
try {
    $socket->Connect('example.com', 5000, $bTls, $maxWaitMs);

    // 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.
    $messageLength = 512;
    $socket->SendCount($messageLength);
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

echo "Length prefix sent.\n";