let net = require('net');

let client= new net.Socket();
//创建socket客户端
client.setEncoding('binary');
//连接到服务端
client.connect(3000,'127.0.0.1',function(){
  client.write('hello server');
  //向端口写入数据到达服务端
});
client.on('data',function(data){
  console.log('from server:'+ data);
  //得到服务端返回来的数据
});
client.on('error',function(error){
//错误出现之后关闭连接
  console.log('error:'+error);
  client.destory();
});
client.on('close',function(){
//正常关闭连接
  console.log('Connection closed');
});