DiscoveryService.php

#!/usr/bin/php5-cgi -q

<?php
// Set time limit to indefinite execution
set_time_limit(0);

// Set the ip and port we will listen on
$address = '172.31.1.146';
$port = 1900;
$max_clients = 10;

// Array that will hold client information
$clients = Array();

// Create a TCP Stream socket
$sock = socket_create(AF_INET, SOCK_STREAM, 0);
// Bind the socket to an address/port
socket_bind($sock, $address, $port) or die('Could not bind to address');
// Start listening for connections
socket_listen($sock);

echo "Client started";

// Loop continuously
while (true) {
    // Setup clients listen socket for reading
    $read[0] = $sock;
    for ($i = 0; $i < $max_clients; $i++) {
        if ($client[$i]['sock'] != null)
            $read[$i + 1] = $client[$i]['sock'];
    }
    // Set up a blocking call to socket_select()
    $ready = socket_select($read,$write=null,$except=null,null);
    /* if a new connection is being made add it to the client array */
    echo "Client connected";
    if (in_array($sock, $read)) {
        for ($i = 0; $i < $max_clients; $i++) {
            if ($client[$i]['sock'] == null) {
                $client[$i]['sock'] = socket_accept($sock);
                break;
            } elseif ($i == $max_clients - 1)
                print ("too many clients");
        }
        if (--$ready <= 0)
            continue;
    } // end if in_array
    // If a client is trying to write - handle it now
    for ($i = 0; $i < $max_clients; $i++) { // for each client
        if (in_array($client[$i]['sock'], $read)) {
            $input = socket_read($client[$i]['sock'], 1024);
            if ($input == null) {
                // Zero length string meaning disconnected
                unset($client[$i]);
            }
            $n = trim($input);
            if ($input == 'exit') {
                echo "Closing Connection";
                // requested disconnect
                socket_close($client[$i]['sock']);
            } elseif ($input) {
                // strip white spaces and write back to user
                //$output = ereg_replace("[ \t\n\r]", "", $input) . chr(0);
                $output = "Message Received";
                socket_write($client[$i]['sock'], $output);
            }
            print($input);
        } else {
            // Close the socket
            //socket_close($client[$i]['sock']);
            socket_close($sock);
            unset($client[$i]);
        }
    }
    echo "HERE";
} // end while
// Close the master sockets
socket_close($sock);
echo "CLOSED";
?>