net.createServer([options][, connectionListener])

• options <Object>
  • allowHalfOpen <boolean> 表明是否允许半开的 TCP 连接。默认值: false。
  • pauseOnConnect <boolean> 表明是否应在传入连接上暂停套接字。默认值: false。
• connectionListener <Function> 自动设置为 'connection' 事件的监听器。
• 返回: <net.Server>

创建一个新的 TCP 或 IPC 服务器。

如果 allowHalfOpen 被设置为 true，则当套接字的另一端发送 FIN 数据包时，服务器将仅在 socket.end() 被显式调用发回 FIN 数据包，直到此时连接为半封闭状态（不可读但仍然可写）。 有关详细信息，参见 'end' 事件和 RFC 1122（第 4.2.2.13 节）。

如果 pauseOnConnect 被设置为 true，则与每个传入连接关联的套接字会被暂停，并且不会从其句柄读取任何数据。 这允许在进程之间传递连接，而原始进程不会读取任何数据。 要从暂停的套接字开始读取数据，则调用 socket.resume()。

服务器可以是一个 TCP 服务器或 IPC 服务器，这取决于 listen() 监听什么。

以下是一个 TCP 回声服务器的示例，在 8124 端口上监听连接：

const net = require('net');
const server = net.createServer((c) => {
  // 'connection' 监听器。
  console.log('客户端已连接');
  c.on('end', () => {
    console.log('客户端已断开连接');
  });
  c.write('你好\r\n');
  c.pipe(c);
});
server.on('error', (err) => {
  throw err;
});
server.listen(8124, () => {
  console.log('服务器已启动');
});

使用 telnet 测试：

$ telnet localhost 8124

要想在 /tmp/echo.sock 上监听：

server.listen('/tmp/echo.sock', () => {
  console.log('服务器已启动');
});

使用 nc 连接到 Unix 域套接字服务器：

$ nc -U /tmp/echo.sock

• options <Object>
  • allowHalfOpen <boolean> Indicates whether half-opened TCP connections are allowed. Default: false.
  • pauseOnConnect <boolean> Indicates whether the socket should be paused on incoming connections. Default: false.
• connectionListener <Function> Automatically set as a listener for the 'connection' event.
• Returns: <net.Server>

Creates a new TCP or IPC server.

If allowHalfOpen is set to true, when the other end of the socket sends a FIN packet, the server will only send a FIN packet back when socket.end() is explicitly called, until then the connection is half-closed (non-readable but still writable). See 'end' event and RFC 1122 (section 4.2.2.13) for more information.

If pauseOnConnect is set to true, then the socket associated with each incoming connection will be paused, and no data will be read from its handle. This allows connections to be passed between processes without any data being read by the original process. To begin reading data from a paused socket, call socket.resume().

The server can be a TCP server or an IPC server, depending on what it listen() to.

Here is an example of an TCP echo server which listens for connections on port 8124:

const net = require('net');
const server = net.createServer((c) => {
  // 'connection' listener.
  console.log('client connected');
  c.on('end', () => {
    console.log('client disconnected');
  });
  c.write('hello\r\n');
  c.pipe(c);
});
server.on('error', (err) => {
  throw err;
});
server.listen(8124, () => {
  console.log('server bound');
});

Test this by using telnet:

$ telnet localhost 8124

To listen on the socket /tmp/echo.sock:

server.listen('/tmp/echo.sock', () => {
  console.log('server bound');
});

Use nc to connect to a Unix domain socket server:

$ nc -U /tmp/echo.sock