Examples

Example #1 Socket example: Simple TCP/IP server

This example shows a simple talkback server. Change the address and port variables to suit your setup and execute. You may then connect to the server with a command similar to: telnet 192.168.1.53 10000 (where the address and port match your setup). Anything you type will then be output on the server side, and echoed back to you. To disconnect, enter 'quit'.


#!/usr/local/bin/php -q
<?php
error_reporting(E_ALL);

/* Allow the script to hang around waiting for connections. */
set_time_limit(0);

/* Turn on implicit output flushing so we see what we're getting
 * as it comes in. */
ob_implicit_flush();

$address = '192.168.1.53';
$port = 10000;

if (($sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP)) === false) {
    echo "socket_create() failed: reason: " . socket_strerror(socket_last_error()) . "\n";
}

if (socket_bind($sock, $address, $port) === false) {
    echo "socket_bind() failed: reason: " . socket_strerror(socket_last_error($sock)) . "\n";
}

if (socket_listen($sock, 5) === false) {
    echo "socket_listen() failed: reason: " . socket_strerror(socket_last_error($sock)) . "\n";
}

do {
    if (($msgsock = socket_accept($sock)) === false) {
        echo "socket_accept() failed: reason: " . socket_strerror(socket_last_error($sock)) . "\n";
        break;
    }
    /* Send instructions. */
    $msg = "\nWelcome to the PHP Test Server. \n" .
        "To quit, type 'quit'. To shut down the server type 'shutdown'.\n";
    socket_write($msgsock, $msg, strlen($msg));

    do {
        if (false === ($buf = socket_read($msgsock, 2048, PHP_NORMAL_READ))) {
            echo "socket_read() failed: reason: " . socket_strerror(socket_last_error($msgsock)) . "\n";
            break 2;
        }
        if (!$buf = trim($buf)) {
            continue;
        }
        if ($buf == 'quit') {
            break;
        }
        if ($buf == 'shutdown') {
            socket_close($msgsock);
            break 2;
        }
        $talkback = "PHP: You said '$buf'.\n";
        socket_write($msgsock, $talkback, strlen($talkback));
        echo "$buf\n";
    } while (true);
    socket_close($msgsock);
} while (true);

socket_close($sock);
?>

Example #2 Socket example: Simple TCP/IP client

This example shows a simple, one-shot HTTP client. It simply connects to a page, submits a HEAD request, echoes the reply, and exits.


<?php
error_reporting(E_ALL);

echo "<h2>TCP/IP Connection</h2>\n";

/* Get the port for the WWW service. */
$service_port = getservbyname('www', 'tcp');

/* Get the IP address for the target host. */
$address = gethostbyname('www.example.com');

/* Create a TCP/IP socket. */
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
if ($socket === false) {
    echo "socket_create() failed: reason: " . socket_strerror(socket_last_error()) . "\n";
} else {
    echo "OK.\n";
}

echo "Attempting to connect to '$address' on port '$service_port'...";
$result = socket_connect($socket, $address, $service_port);
if ($result === false) {
    echo "socket_connect() failed.\nReason: ($result) " . socket_strerror(socket_last_error($socket)) . "\n";
} else {
    echo "OK.\n";
}

$in = "HEAD / HTTP/1.1\r\n";
$in .= "Host: www.example.com\r\n";
$in .= "Connection: Close\r\n\r\n";
$out = '';

echo "Sending HTTP HEAD request...";
socket_write($socket, $in, strlen($in));
echo "OK.\n";

echo "Reading response:\n\n";
while ($out = socket_read($socket, 2048)) {
    echo $out;
}

echo "Closing socket...";
socket_close($socket);
echo "OK.\n\n";
?>

User Contributed Notes

javier,javiern at gmail dot com

3 years ago


You can easily extend the first example to handle any number of connections instead of jsut one

#!/usr/bin/env php
<?php
error_reporting(E_ALL);

/* Permitir al script esperar para conexiones. */
set_time_limit(0);

/* Activar el volcado de salida implícito, así veremos lo que estamo obteniendo
 * mientras llega. */
ob_implicit_flush();

$address = '127.0.0.1';
$port = 10000;

if (($sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP)) === false) {
    echo "socket_create() falló: razón: " . socket_strerror(socket_last_error()) . "\n";
}

if (socket_bind($sock, $address, $port) === false) {
    echo "socket_bind() falló: razón: " . socket_strerror(socket_last_error($sock)) . "\n";
}

if (socket_listen($sock, 5) === false) {
    echo "socket_listen() falló: razón: " . socket_strerror(socket_last_error($sock)) . "\n";
}

//clients array
$clients = array();

do {
    $read = array();
    $read[] = $sock;
    
    $read = array_merge($read,$clients);
    
    // Set up a blocking call to socket_select
    if(socket_select($read,$write = NULL, $except = NULL, $tv_sec = 5) < 1)
    {
        //    SocketServer::debug("Problem blocking socket_select?");
        continue;
    }
    
    // Handle new Connections
    if (in_array($sock, $read)) {        
        
        if (($msgsock = socket_accept($sock)) === false) {
            echo "socket_accept() falló: razón: " . socket_strerror(socket_last_error($sock)) . "\n";
            break;
        }
        $clients[] = $msgsock;
        $key = array_keys($clients, $msgsock);
        /* Enviar instrucciones. */
        $msg = "\nBienvenido al Servidor De Prueba de PHP. \n" .
        "Usted es el cliente numero: {$key[0]}\n" .
        "Para salir, escriba 'quit'. Para cerrar el servidor escriba 'shutdown'.\n";
        socket_write($msgsock, $msg, strlen($msg));
        
    }
    
    // Handle Input
    foreach ($clients as $key => $client) { // for each client        
        if (in_array($client, $read)) {
            if (false === ($buf = socket_read($client, 2048, PHP_NORMAL_READ))) {
                echo "socket_read() falló: razón: " . socket_strerror(socket_last_error($client)) . "\n";
                break 2;
            }
            if (!$buf = trim($buf)) {
                continue;
            }
            if ($buf == 'quit') {
                unset($clients[$key]);
                socket_close($client);
                break;
            }
            if ($buf == 'shutdown') {
                socket_close($client);
                break 2;
            }
            $talkback = "Cliente {$key}: Usted dijo '$buf'.\n";
            socket_write($client, $talkback, strlen($talkback));
            echo "$buf\n";
        }
        
    }        
} while (true);

socket_close($sock);
?>

Anonymous

2 years ago


A more object oriented example of the server

#!/usr/bin/env php
<?php

class MySocketServer
{
    protected $socket;
    protected $clients = [];
    protected $changed;
    
    function __construct($host = 'localhost', $port = 9000)
    {
        set_time_limit(0);
        $socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
        socket_set_option($socket, SOL_SOCKET, SO_REUSEADDR, 1);

        //bind socket to specified host
        socket_bind($socket, 0, $port);
        //listen to port
        socket_listen($socket);
        $this->socket = $socket;
    }
    
    function __destruct()
    {
        foreach($this->clients as $client) {
            socket_close($client);
        }
        socket_close($this->socket);
    }
    
    function run()
    {
        while(true) {
            $this->waitForChange();
            $this->checkNewClients();
            $this->checkMessageRecieved();
            $this->checkDisconnect();
        }
    }
    
    function checkDisconnect()
    {
        foreach ($this->changed as $changed_socket) {
            $buf = @socket_read($changed_socket, 1024, PHP_NORMAL_READ);
            if ($buf !== false) { // check disconnected client
                continue;
            }
            // remove client for $clients array
            $found_socket = array_search($changed_socket, $this->clients);
            socket_getpeername($changed_socket, $ip);
            unset($this->clients[$found_socket]);
            $response = 'client ' . $ip . ' has disconnected';
            $this->sendMessage($response);
        }
    }
    
    function checkMessageRecieved()
    {
        foreach ($this->changed as $key => $socket) {
            $buffer = null;
            while(socket_recv($socket, $buffer, 1024, 0) >= 1) {
                $this->sendMessage(trim($buffer) . PHP_EOL);
                unset($this->changed[$key]);
                break;
            }
        }
    }
    
    function waitForChange()
    {
        //reset changed
        $this->changed = array_merge([$this->socket], $this->clients);
        //variable call time pass by reference req of socket_select
        $null = null;
        //this next part is blocking so that we dont run away with cpu
        socket_select($this->changed, $null, $null, null);
    }
    
    function checkNewClients()
    {
        if (!in_array($this->socket, $this->changed)) {
            return; //no new clients
        }
        $socket_new = socket_accept($this->socket); //accept new socket
        $first_line = socket_read($socket_new, 1024);
        $this->sendMessage('a new client has connected' . PHP_EOL);
        $this->sendMessage('the new client says ' . trim($first_line) . PHP_EOL);
        $this->clients[] = $socket_new;
        unset($this->changed[0]);
    }
    
    
    function sendMessage($msg)
    {
        foreach($this->clients as $client)
        {
            @socket_write($client,$msg,strlen($msg));
        }
        return true;
    }
}

(new MySocketServer())->run();
?>

Anonymous

2 years ago


The variable $in in TCP client exampe really needs to end with '\n' or otherwise it doesn't fire the read event in the server side (at least in my Delphi program).