What are the common errors or issues that may arise when trying to establish a socket connection between a C++ client program and a PHP server script in a different port?

One common issue that may arise when trying to establish a socket connection between a C++ client program and a PHP server script in a different port is mismatched port numbers. Ensure that both the client and server are using the same port number for communication. Additionally, check for any firewall restrictions that may be blocking the connection.

<?php
$port = 12345; // Specify the port number for communication
$server = stream_socket_server("tcp://0.0.0.0:$port", $errno, $errstr);

if (!$server) {
    die("Error creating socket: $errstr ($errno)");
}

echo "Server listening on port $port\n";

while ($conn = stream_socket_accept($server)) {
    $data = fread($conn, 1024);
    echo "Received data: $data\n";
    
    fwrite($conn, "Hello from PHP server!");
    
    fclose($conn);
}

fclose($server);
?>