Perl

Send and Receive WebSocket Messages

See more WebSocket Examples

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.

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 $ws = Chilkat2::WebSocket->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.

my $rest = Chilkat2::Rest->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.
my $success = $rest->Connect('websockets.chilkat.io', 80, 0, 0);
$ws->UseConnection($rest);
$ws->AddClientHeaders();
my $responseBodyIgnored = $rest->FullRequestNoBody('GET', '/wsChilkatEcho.ashx');
$success = $ws->ValidateServerHandshake();
if (!$success) {
    print $ws->LastErrorText, "\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.
my $finalFrame = 0;
$success = $ws->SendFrame("This is the 1st frame\r\n", $finalFrame);
if (!$success) {
    print $ws->LastErrorText, "\n";
    exit;
}

# Send the 2nd frame in the message.
$success = $ws->SendFrame("This is the 2nd frame\r\n", $finalFrame);
if (!$success) {
    print $ws->LastErrorText, "\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) {
    print $ws->LastErrorText, "\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.
my $receivedFinalFrame = 0;
while (!$receivedFinalFrame) {
    $success = $ws->ReadFrame();
    if (!$success) {
        print "Failed to receive a frame\n";
        print 'ReadFrame fail reason = ', $ws->ReadFrameFailReason, "\n";
        print $ws->LastErrorText, "\n";
        exit;
    }

    $receivedFinalFrame = $ws->FinalFrame;

    # Show the opcode and final frame bit for the frame just received:
    print 'Frame opcode: ', $ws->FrameOpcode, "\n";
    print 'Final frame: ', ($receivedFinalFrame ? 1 : 0), "\n";
}

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

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

# Read the Close response.
$success = $ws->ReadFrame();
if (!$success) {
    print 'ReadFrame fail reason = ', $ws->ReadFrameFailReason, "\n";
    print $ws->LastErrorText, "\n";
    exit;
}

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

print "Success.\n";