Perl

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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Perl

use chilkat();

$success = 0;

$socket = chilkat::CkSocket->new();

#  Connect to the server using TLS.
$bTls = 1;
$maxWaitMs = 5000;
$success = $socket->Connect("example.com",5000,$bTls,$maxWaitMs);
if ($success == 0) {
    print $socket->lastErrorText() . "\r\n";
    exit;
}

#  Read a four-byte length prefix as a signed 32-bit integer (network byte order by default).  A
#  return value of -1 indicates failure.
$messageLength = $socket->ReceiveCount();
if ($messageLength < 0) {
    print $socket->lastErrorText() . "\r\n";
    exit;
}

print "The peer will send " . $messageLength . " bytes." . "\r\n";