server 端

1. socket_create()：创建一个套接字
2. socket_bind()：给套接字绑定名字
3. socket_listen()：监听套接字上的连接
4. socket_set_nonblock（）：非阻塞
5. socket_read()：获得客户端输入内容
6. socket_write()：写数据到socket

<?php
$sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP) or die('create fail');
socket_bind($sock, $ip, $port) or die('bind fail');
socket_listen($sock, 128) or die('listen fail');

socket_set_nonblock($sock);
while(true){
	$accept = socket_accept($sock);
	if(!$accept){
		echo 'accept fail' . PHP_EOL;
	} else {
		socket_write($accept, 'success', strlen('success'));
	}
}

socket_close($sock);

client 端

1. socket_create()
2. socket_connect()
3. socket_write()
4. socket_read()

<?php
$ip = '127.0.0.1';
$port = 9951;

$sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP) or die('create fail');

$connect = socket_connect($sock, $ip, $port) or die('connect fail');

//向服务端发送内容
socket_write($sock, 'test msg', strlen('test msg'));

//读取服务端返回内容
$server_msg = socket_read($sock, 1024);

echo 'server：' . $server_msg . PHP_EOL;

socket_close($sock); //关闭连接资源