(Perl) Send and Receive WebSocket Messages

This example how to send and receive websocket messages.

A WebSocket message can be composed of one or more frames. The simple case is where a single frame is both the first and last frame in a message. This is the case where the 1st frame in the message has the "final frame" bit set.

This example demonstrates sending and receiving multi-frame messages.

Note: The websockets.chilkat.io server imposes the following limitations:
Messages must be 16K or less, and each connection is limited to a max of 16 echoed messages.

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

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

$ws = chilkat::CkWebSocket->new();

# For brevity, this example does not check for errors when etablishing the WebSocket connection.
# See Establish WebSocket Connection for more complete sample code for making the connection.

$rest = chilkat::CkRest->new();
# Connect to websockets.chilkat.io
# IMPORTANT: websockets.chilkat.io accepts frames of up to 16K in size and echoes them back.
# IMPORTANT: The websockets.chilkat.io server imposes the following limitations: 
# ---------- Messages must be 16K or less, and each connection is limited to a max of 16 echoed messages.
$success = $rest->Connect("websockets.chilkat.io",80,0,0);
$ws->UseConnection($rest);
$ws->AddClientHeaders();
$responseBodyIgnored = $rest->fullRequestNoBody("GET","/wsChilkatEcho.ashx");
$success = $ws->ValidateServerHandshake();
if ($success != 1) {
    print $ws->lastErrorText() . "\r\n";
    exit;
}

# This example demonstrates sending and receiving a multi-frame message.

# The websocket message will be composed of three text lines, each frame will contain a single line.

# Send the 1st frame in the message.
$finalFrame = 0;
$success = $ws->SendFrame("This is the 1st frame\r\n",$finalFrame);
if ($success != 1) {
    print $ws->lastErrorText() . "\r\n";
    exit;
}

# Send the 2nd frame in the message.
$success = $ws->SendFrame("This is the 2nd frame\r\n",$finalFrame);
if ($success != 1) {
    print $ws->lastErrorText() . "\r\n";
    exit;
}

# Send the 3rd and final frame in the message.
$finalFrame = 1;
$success = $ws->SendFrame("This is the 3rd frame\r\n",$finalFrame);
if ($success != 1) {
    print $ws->lastErrorText() . "\r\n";
    exit;
}

# Read an incoming frames until we receive the final frame.
# Note: It may be that the echo server (websockets.chilkat.io) responds with 
# the full message in a single final frame.
$receivedFinalFrame = 0;
while ($receivedFinalFrame == 0) {

    $success = $ws->ReadFrame();
    if ($success != 1) {
        print "Failed to receive a frame" . "\r\n";
        print "ReadFrame fail reason = " . $ws->get_ReadFrameFailReason() . "\r\n";
        print $ws->lastErrorText() . "\r\n";
        exit;
    }

    $receivedFinalFrame = $ws->get_FinalFrame();

    # Show the opcode and final frame bit for the frame just received:
    print "Frame opcode: " . $ws->frameOpcode() . "\r\n";
    print "Final frame: " . $receivedFinalFrame . "\r\n";
}

# Return the message accumulated in the above calls to ReadFrame.
$receivedMsg = $ws->getFrameData();
print "Received: " . $receivedMsg . "\r\n";

# Close the websocket connection.
$success = $ws->SendClose(1,1000,"Closing this websocket.");
if ($success != 1) {
    print $ws->lastErrorText() . "\r\n";
    exit;
}

# Read the Close response.
$success = $ws->ReadFrame();
if ($success != 1) {
    print "ReadFrame fail reason = " . $ws->get_ReadFrameFailReason() . "\r\n";
    print $ws->lastErrorText() . "\r\n";
    exit;
}

# Should receive the "Close" opcode.
print "Received opcode: " . $ws->frameOpcode() . "\r\n";
# Should be the same status code we sent (1000)
print "Received close status code: " . $ws->get_CloseStatusCode() . "\r\n";
# The server may echo the close reason.  If not, this will be empty.
print "Echoed close reason: " . $ws->closeReason() . "\r\n";

print "Success." . "\r\n";