Coroutine TCP/UDP Client Working Example

Description

Below is a complete TCP/UDP client example, use this to understand how the client works and how to send and receive data. There is also some basic error checking in place but you should add your own logic to handle errors other than a timeout. Use both $client->errCode or $client->errMsg to check for errors.

Full Working Example

<?php

use OpenSwoole\Coroutine as Co;
use OpenSwoole\Coroutine\Client;

co::run(function()
{
    $client = new Client(OpenSwoole\Constant::SOCK_TCP);

    // Connect to the remote server, handle any errors as well...
    if(!$client->connect('127.0.0.1', 9501, 0.5))
    {
        echo "Connection Failed. Error: {$client->errCode}\n";
    }

    // Send data to the connected server
    $client->send("Hello World! - From OpenSwoole.\n");

    while(true)
    {
        // Keep reading data in using this loop
        $data = $client->recv();

        // Check if we have any data or not
        if(strlen($data) > 0)
        {
            echo $data . "\n";
            $client->send(time() . PHP_EOL);
        }
        else
        {
            // An empty string means the connection has been closed
            if($data === '')
            {
                // We must close the connection to use the client again
                $client->close();
                break;
            }
            else
            {
                // False means there was an error we need to check
                if($data === false)
                {
                    // You should use $client->errCode to handle errors yourself

                    // A timeout error will not close the connection.
                    if($client->errCode !== SOCKET_ETIMEDOUT)
                    {
                        // Not a timeout, close the connection due to an error
                        $client->close();
                        break;
                    }
                }
                else
                {
                    // Unknown error, close and break out of the loop
                    $client->close();
                    break;
                }
            }
        }

        // Wait 1 second before reading data again on our loop
        Co::sleep(1);
    }
});