PHP WebSocket Functions Overview

Here’s an overview of the PHP socket functions:

socket_create()

This function is used to create a socket resource that represents a network socket.

It accepts three parameters: the address (Ex: AF_INET for IPv4), the socket type (Ex: SOCK_STREAM for TCP), and the protocol (Ex: SOL_TCP for TCP).

It returns a socket resource on success or false on failure.

$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);

socket_bind()

The socket_bind() PHP function is used to bind a socket to a specific address and a port.

It accepts the socket resource as the first parameter, followed by the IP address and port number.

When a socket is bound to a certain address, it can listen for incoming connections on that address.

// Bind the socket to a specific address and port
$bindResult = socket_bind($socket, '127.0.0.1', 8080);

if ($bindResult === false) {
    // Handle bind failure
    echo "Failed to bind: " . socket_strerror(socket_last_error()) . "\n";
} else {
    // Socket successfully bound
    // Perform further operations (e.g., listen, accept connections)
}

socket_connect()

In PHP, the socket_connect() function is used to connect to a remote socket. It is most commonly used in socket programming to establish a connection to a remote server or socket endpoint.

// Connect to a remote server
$result = socket_connect($socket, '127.0.0.1', 8080);

if ($result === false) {
    // Handle connection failure
    echo "Failed to connect: " . socket_strerror(socket_last_error()) . "\n";
} else {
    // Connection successful
    // Use the socket for further operations (e.g., send, receive)
}

socket_listen()

The socket_listen() function in PHP is used to make a socket listen for incoming connections. It configures a bound socket to accept connections from clients.

// Bind the socket to a specific address and port
socket_bind($socket, '127.0.0.1', 8080);

// Listen for incoming connections
$listenResult = socket_listen($socket, 5);

if ($listenResult === false) {
    // Handle listen failure
    echo "Failed to listen: " . socket_strerror(socket_last_error()) . "\n";
} else {
    // Socket is now listening for connections
    // Accept incoming connections or perform other operations
}

socket_accept()

The socket_accept() function in PHP is used to accept an incoming connection on a listening socket. It creates a new socket resource dedicated to the specific client connection.

// Bind the socket to a specific address and port
socket_bind($socket, '127.0.0.1', 8080);

// Listen for incoming connections
socket_listen($socket, 5);

// Accept an incoming connection
$clientSocket = socket_accept($socket);

if ($clientSocket === false) {
    // Handle accept failure
    echo "Failed to accept connection: " . socket_strerror(socket_last_error()) . "\n";
} else {
    // Connection accepted
    // Use $clientSocket for further communication with the client
}

// Close the client socket
socket_close($clientSocket);

socket_read()

The socket_read() function in PHP is used to read data from a socket. It allows you to receive data sent from the remote endpoint through the established connection.

// Connect to a remote server
socket_connect($socket, '127.0.0.1', 8080);

// Read data from the socket
$data = socket_read($socket, 1024);

if ($data === false) {
    // Handle read failure
    echo "Failed to read from socket: " . socket_strerror(socket_last_error()) . "\n";
} else {
    // Data read successfully
    echo "Received data: " . $data . "\n";
}

socket_write()

The socket_write() function in PHP is used to send data through a socket. It allows you to transmit data to the remote endpoint with which you have established a connection.

// Connect to a remote server
socket_connect($socket, '127.0.0.1', 8080);

// Send data through the socket
$data = "Hello, server! I am Sanjay";
$bytesSent = socket_write($socket, $data, strlen($data));

if ($bytesSent === false) {
    // Handle write failure
    echo "Failed to write to socket: " . socket_strerror(socket_last_error()) . "\n";
} else {
    // Data sent successfully
    echo "Sent $bytesSent bytes to the server.\n";
}

socket_close()

The socket_close() function in PHP is used to close a socket connection. It releases the resources associated with the socket and terminates the connection.

$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);

// Connect to a remote server
socket_connect($socket, '127.0.0.1', 8080);

// Perform operations with the socket

// Close the socket
socket_close($socket);

You can use these PHP socket functions to establish, bind, connect, listen, accept, read from, write to, and close network sockets. They give PHP users low-level access to socket programming capabilities.

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