PHP method to implement communication function between client and server based on socket

<?php
  set_time_limit(0);
  $host="localhost";
  $port=1001;
  //创建一个连接
  $socket=socket_create(AF_INET,SOCK_STREAM,SOL_TCP)or die("cannot create socket\n");
  //绑定socket到端口
  $result=socket_bind($socket,$host,$port) or die("cannot bind port to socket\n");
  //开始监听这个端口
  $result=socket_listen($socket,4) or die("could not set up socket listen\n");
  //接受连接，另一个socket来处理通信
  $msgsock=socket_accept($socket) or die("cannot accept incoming connection\n");
  if($msgsock){
    echo date("Y-m-d H:i:s D a");
  }
  //读取客户端发送过来的信息
  $input=socket_read($msgsock,1024) or die("cannot read input\n");
  $input=trim($input);
  $output=strrev($input)."顺序反过来了吧\n";
  //对接收到的信息进行处理，然后返回到客户端
  socket_write($msgsock,$output,strlen($output)) or die("cannot write");
  //关闭socket连接
  socket_close($msgsock);
  socket_close($socket);
?>

<?php
  set_time_limit(0);
  $host="localhost";
  $port=1001;
  //创建一个socket
  $socket=socket_create(AF_INET,SOCK_STREAM,SOL_TCP)or die("cannot create socket\n");
  $conn=socket_connect($socket,$host,$port) or die("cannot connect server\n");
  if($conn){echo "client connect ok!";}
  socket_write($socket,"hello world!") or die("cannot write data\n");
  $buffer=socket_read($socket,1024,PHP_NORMAL_READ);
  if($buffer){
    echo "response was:".$buffer."\n";
  }
  socket_close($socket);
?>