利用PHP如何实现Socket服务器

socket服务器的工作方式是这样的，不间断地运行以等待客户端的连接。一旦客户端连接上了，服务器就会将它添加到客户名单中，然后开始等待来自客户端的消息。

不要走开，下面是完整的源代码：

// Set time limit to indefinite execution set_time_limit (0);  // Set the ip and port we will listen on $address = 'localhost'; $port = 10000; $max_clients = 10;  // Array that will hold client information $client = 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 "Waiting for connections.../r/n";  // Loop continuously while (true) { // Setup clients listen socket for reading $read[0] = $sock; for ($i = 0; $i < $max_clients; $i++) {  if (isset($client[$i]['sock']))   $read[$i + 1] = $client[$i]['sock']; } // Set up a blocking call to socket_select() if (socket_select($read, $write = NULL, $except = NULL, $tv_sec = 5) < 1)  continue; /* if a new connection is being made add it to the client array */ if (in_array($sock, $read)) {  for ($i = 0; $i < $max_clients; $i++) {   if (empty($client[$i]['sock'])) {   $client[$i]['sock'] = socket_accept($sock);   echo "New client connected $i/r/n";   break;   }   elseif ($i == $max_clients - 1)   echo "Too many clients.../r/n";  } } // end if in_array  // If a client is trying to write - handle it now for ($i = 0; $i < $max_clients; $i++) { // for each client  if (isset($client[$i]['sock'])) {   if (in_array($client[$i]['sock'], $read)) {   $input = socket_read($client[$i]['sock'], 1024);   if ($input == null) {    echo "Client disconnecting $i/r/n";    // Zero length string meaning disconnected    unset($client[$i]);   } else {    echo "New input received $i/r/n";    // send it to the other clients    for ($j = 0; $j < $max_clients; $j++) {    if (isset($client[$j]['sock']) && $j != $i) {     echo "Writing '$input' to client $j/r/n";     socket_write($client[$j]['sock'], $input, strlen($input));    }    }    if ($input == 'exit') {    // requested disconnect    socket_close($client[$i]['sock']);    }   }   } else {   echo "Client disconnected $i/r/n";   // Close the socket   socket_close($client[$i]['sock']);   unset($client[$i]);   }  } } } // end while // Close the master sockets socket_close($sock); 

哎呀，乍一看这似乎是一个大工程，但是我们可以先将它分解为几个较小的部分。

第一部分是创建服务器。Lines：2至20。

这部分代码设置了变量、地址、端口、最大客户端和客户端数组。接下来创建socket并将其绑定到我们指定的地址和端口上。