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. Perl

use chilkat();

$success = 0;

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

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

# --------------------------------------------------------------------
# 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() . "\r\n";
    exit;
}

# Wait a max of 2 seconds for a response..
$sock->put_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" . "\r\n";
print $hexStr . "\r\n";

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

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

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

print "----" . "\r\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" . "\r\n";
print $hexStr . "\r\n";

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