PHP Sockets - Accept multiple connections

Question

I\'m trying to create a simple client/server application and thus I am experimenting with sockets in PHP.

Now I have a simple client in C# which connects to the server we

Answer 1

This script is working perfectly for me

hooks = array();

            $this->config["ip"] = $bind_ip;
            $this->config["port"] = $port;

            $this->master_socket = socket_create(AF_INET, SOCK_STREAM, 0);
            socket_bind($this->master_socket,$this->config["ip"],$this->config["port"]) or die("Issue Binding");
            socket_getsockname($this->master_socket,$bind_ip,$port);
            socket_listen($this->master_socket);
            SocketServer::debug("Listenting for connections on {$bind_ip}:{$port}");
        }

        /*! @function   hook
            @abstract   Adds a function to be called whenever a certain action happens.  Can be extended in your implementation.
            @param      string  - Command
            @param      callback- Function to Call.
            @see        unhook
            @see        trigger_hooks
            @result     void
         */
        public function hook($command,$function)
        {
            $command = strtoupper($command);
            if(!isset($this->hooks[$command])) { $this->hooks[$command] = array(); }
            $k = array_search($function,$this->hooks[$command]);
            if($k === FALSE)
            {
                $this->hooks[$command][] = $function;
            }
        }

        /*! @function   unhook
            @abstract   Deletes a function from the call list for a certain action.  Can be extended in your implementation.
            @param      string  - Command
            @param      callback- Function to Delete from Call List
            @see        hook
            @see        trigger_hooks
            @result     void
         */
        public function unhook($command = NULL,$function)
        {
            $command = strtoupper($command);
            if($command !== NULL)
            {
                $k = array_search($function,$this->hooks[$command]);
                if($k !== FALSE)
                {
                    unset($this->hooks[$command][$k]);
                }
            } else {
                $k = array_search($this->user_funcs,$function);
                if($k !== FALSE)
                {
                    unset($this->user_funcs[$k]);
                }
            }
        }

        /*! @function   loop_once
            @abstract   Runs the class's actions once.
            @discussion Should only be used if you want to run additional checks during server operation.  Otherwise, use infinite_loop()
            @param      void
            @see        infinite_loop
            @result     bool    - True
        */
        public function loop_once()
        {
            // Setup Clients Listen Socket For Reading
            $read[0] = $this->master_socket;
            for($i = 0; $i < $this->max_clients; $i++)
            {
                if(isset($this->clients[$i]))
                {
                    $read[$i + 1] = $this->clients[$i]->socket;
                }
            }

            // 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?");
                return true;
            }

            // Handle new Connections
            if(in_array($this->master_socket, $read))
            {
                for($i = 0; $i < $this->max_clients; $i++)
                {
                    if(empty($this->clients[$i]))
                    {
                        $temp_sock = $this->master_socket;
                        $this->clients[$i] = new SocketServerClient($this->master_socket,$i);
                        $this->trigger_hooks("CONNECT",$this->clients[$i],"");
                        break;
                    }
                    elseif($i == ($this->max_clients-1))
                    {
                        SocketServer::debug("Too many clients... :( ");
                    }
                }

            }

            // Handle Input
            for($i = 0; $i < $this->max_clients; $i++) // for each client
            {
                if(isset($this->clients[$i]))
                {
                    if(in_array($this->clients[$i]->socket, $read))
                    {
                        $input = socket_read($this->clients[$i]->socket, $this->max_read);
                        if($input == null)
                        {
                            $this->disconnect($i);
                        }
                        else
                        {
                            SocketServer::debug("{$i}@{$this->clients[$i]->ip} --> {$input}");
                            $this->trigger_hooks("INPUT",$this->clients[$i],$input);
                        }
                    }
                }
            }
            return true;
        }

        /*! @function   disconnect
            @abstract   Disconnects a client from the server.
            @param      int - Index of the client to disconnect.
            @param      string  - Message to send to the hooks
            @result     void
        */
        public function disconnect($client_index,$message = "")
        {
            $i = $client_index;
            SocketServer::debug("Client {$i} from {$this->clients[$i]->ip} Disconnecting");
            $this->trigger_hooks("DISCONNECT",$this->clients[$i],$message);
            $this->clients[$i]->destroy();
            unset($this->clients[$i]);          
        }

        /*! @function   trigger_hooks
            @abstract   Triggers Hooks for a certain command.
            @param      string  - Command who's hooks you want to trigger.
            @param      object  - The client who activated this command.
            @param      string  - The input from the client, or a message to be sent to the hooks.
            @result     void
        */
        public function trigger_hooks($command,&$client,$input)
        {
            if(isset($this->hooks[$command]))
            {
                foreach($this->hooks[$command] as $function)
                {
                    SocketServer::debug("Triggering Hook '{$function}' for '{$command}'");
                    $continue = call_user_func($function,&$this,&$client,$input);
                    if($continue === FALSE) { break; }
                }
            }
        }

        /*! @function   infinite_loop
            @abstract   Runs the server code until the server is shut down.
            @see        loop_once
            @param      void
            @result     void
        */
        public function infinite_loop()
        {
            $test = true;
            do
            {
                $test = $this->loop_once();
            }
            while($test);
        }

        /*! @function   debug
            @static
            @abstract   Outputs Text directly.
            @discussion Yeah, should probably make a way to turn this off.
            @param      string  - Text to Output
            @result     void
        */
        public static function debug($text)
        {
            echo("{$text}\r\n");
        }

        /*! @function   socket_write_smart
            @static
            @abstract   Writes data to the socket, including the length of the data, and ends it with a CRLF unless specified.
            @discussion It is perfectly valid for socket_write_smart to return zero which means no bytes have been written. Be sure to use the === operator to check for FALSE in case of an error. 
            @param      resource- Socket Instance
            @param      string  - Data to write to the socket.
            @param      string  - Data to end the line with.  Specify a "" if you don't want a line end sent.
            @result     mixed   - Returns the number of bytes successfully written to the socket or FALSE on failure. The error code can be retrieved with socket_last_error(). This code may be passed to socket_strerror() to get a textual explanation of the error.
        */
        public static function socket_write_smart(&$sock,$string,$crlf = "\r\n")
        {
            SocketServer::debug("<-- {$string}");
            if($crlf) { $string = "{$string}{$crlf}"; }
            return socket_write($sock,$string,strlen($string));
        }

        /*! @function   __get
            @abstract   Magic Method used for allowing the reading of protected variables.
            @discussion You never need to use this method, simply calling $server->variable works because of this method's existence.
            @param      string  - Variable to retrieve
            @result     mixed   - Returns the reference to the variable called.
        */
        function &__get($name)
        {
            return $this->{$name};
        }
    }

    /*! @class      SocketServerClient
        @author     Navarr Barnier
        @abstract   A Client Instance for use with SocketServer
     */
    class SocketServerClient
    {
        /*! @var        socket
            @abstract   resource - The client's socket resource, for sending and receiving data with.
         */
        protected $socket;

        /*! @var        ip
            @abstract   string - The client's IP address, as seen by the server.
         */
        protected $ip;

        /*! @var        hostname
            @abstract   string - The client's hostname, as seen by the server.
            @discussion This variable is only set after calling lookup_hostname, as hostname lookups can take up a decent amount of time.
            @see        lookup_hostname
         */
        protected $hostname;

        /*! @var        server_clients_index
            @abstract   int - The index of this client in the SocketServer's client array.
         */
        protected $server_clients_index;

        /*! @function   __construct
            @param      resource- The resource of the socket the client is connecting by, generally the master socket.
            @param      int - The Index in the Server's client array.
            @result     void
         */
        public function __construct(&$socket,$i)
        {
            $this->server_clients_index = $i;
            $this->socket = socket_accept($socket) or die("Failed to Accept");
            SocketServer::debug("New Client Connected");
            socket_getpeername($this->socket,$ip);
            $this->ip = $ip;
        }

        /*! @function   lookup_hostname
            @abstract   Searches for the user's hostname and stores the result to hostname.
            @see        hostname
            @param      void
            @result     string  - The hostname on success or the IP address on failure.
         */
        public function lookup_hostname()
        {
            $this->hostname = gethostbyaddr($this->ip);
            return $this->hostname;
        }

        /*! @function   destroy
            @abstract   Closes the socket.  Thats pretty much it.
            @param      void
            @result     void
         */
        public function destroy()
        {
            socket_close($this->socket);
        }

        function &__get($name)
        {
            return $this->{$name};
        }

        function __isset($name)
        {
            return isset($this->{$name});
        }
    }

Source on github