Perl

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. Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

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

my $sock = Chilkat2::Socket->new;

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

my $useTls = 0;
my $port = 4242;
my $maxWaitMs = 5000;
my $success = $sock->Connect('tcpbin.com', $port, $useTls, $maxWaitMs);
if (!$success) {
    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
my $value = 12022;
my $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.)
my $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