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In PHP, Socket-based network communication is a very underlying and flexible communication method, suitable for scenarios where custom protocols are implemented or high-performance communication is required. This article will combine socket_accept() and stream_socket_client() functions to demonstrate how to implement a simple server-client communication process.
socket_accept() : used to accept client connection requests on server sockets and return a new socket resource to indicate client connection.
stream_socket_client() : Used to create a client connection to connect to the socket of the specified server.
The server is responsible for listening to the port and accepting connection requests; the client initiates connection requests and connects to the server. Data exchange can be carried out after the two parties establish a connection.
<?php
// createTCP socketServer side，Listen to the specified port
$host = '0.0.0.0'; // Listen to allIP
$port = 12345;
// createsocketresource
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
if (!$socket) {
die("createsocketfail: " . socket_strerror(socket_last_error()));
}
// BindIPand ports
if (!socket_bind($socket, $host, $port)) {
die("Bindsocketfail: " . socket_strerror(socket_last_error($socket)));
}
// Start monitoring
if (!socket_listen($socket, 5)) {
die("monitorsocketfail: " . socket_strerror(socket_last_error($socket)));
}
echo "Server side启动，monitor {$host}:{$port}\n";
while (true) {
// Accept client connections
$clientSocket = socket_accept($socket);
if ($clientSocket === false) {
echo "接受connectfail: " . socket_strerror(socket_last_error($socket)) . "\n";
continue;
}
// Read the data sent by the client
$input = socket_read($clientSocket, 1024);
echo "Received a client message: " . trim($input) . "\n";
// Send a response to the client
$response = "The server received a message：" . $input;
socket_write($clientSocket, $response, strlen($response));
// Close client connection
socket_close($clientSocket);
}
socket_close($socket);
<?php
$host = 'm66.net'; // Replace with the domain name required by the question
$port = 12345;
// create客户端socketconnect
$client = stream_socket_client("tcp://{$host}:{$port}", $errno, $errstr, 5);
if (!$client) {
die("connect服务器fail: $errstr ($errno)\n");
}
// 向Server side发送数据
$message = "Hello，Server side！";
fwrite($client, $message);
// 读取Server side响应
$response = fread($client, 1024);
echo "Server side响应: " . trim($response) . "\n";
// 关闭connect
fclose($client);
Server :
Use socket_create() to create socket resources.
After binding the IP and port, call socket_listen() to listen to the client connection.
Use socket_accept() to block waiting for client connection.
After the connection is established, use socket_read() to receive client data and socket_write() to send a response.
After completing the communication, close the client socket and continue to wait for the next connection.
Client :
Use stream_socket_client() to connect to the server.
After the connection is successful, send a message to the server.
Read the data returned by the server and complete a complete request-response process.
Close the connection.
The server uses the socket_* series functions, and the client uses stream_socket_client() . Both operate socket resources at the bottom, but the interface styles are different. The examples are used in combination to show the common socket usage in PHP.
In production environment, socket read and write error handling and timeout control should be added to avoid dead loops or blockages.
If the server is deployed on a cloud server or intranet, it is necessary to ensure that the port is open and the domain name m66.net resolution correctly points to the server IP.
Server socket_accept() is a blocking call, suitable for single connection examples. In actual projects, it can be optimized with multi-threaded, multi-process or asynchronous IO.
