PHP code to implement Socket server_PHP tutorial

This article mainly introduces the example of PHP simple socket server client code. This article gives two versions of the server port, explains the problems and improvements of the code, and gives the client using this socket server. Code, friends who need it can refer to

This article shares a simple socket example, using php. Implement a TCP service that receives an input string, processes and returns this string to the client.

Generate a socket server

<?php
/*文件名：socket_server.php*/
// 设置一些基本的变量
$host="127.0.0.1";//Socket运行的服务器的IP地址
$port=1234;//Socket运行的服务器的端口，端口取值为1到65535之间的数字，前提是这个端口未被使用
// 设置超时时间，这里设置为永不超时，确保PHP在等待客户端连接时不会超时。
set_time_limit(0);
// 创建一个Socket，返回一个Socket句柄
$socket=socket_create(AF_INET,SOCK_STREAM,0) or die("Could not create socket\n");
//绑定Socket到指定的地址和端口
$result=socket_bind($socket,$host,$port) or die("Could not bind to socket\n");
// 开始监听外部连接
$result=socket_listen($socket,3) or die("Could not set up socket listener\n");
/******到这里，服务器除了等待来自客户端的连接请求外基本上什么也不做******/
// 另一个Socket来处理服务端与客户端的通信
$spawn=socket_accept($socket) or die("Could not accept incoming connection\n");
// 读取客户端的输入，当一个连接被建立后,服务器就会等待客户端发送一些输入信息,这些信息可以由socket_read()函数来获得,并把它赋值给PHP的$input变量
$input=socket_read($spawn,1024) or die("Could not read input\n");
//socker_read的第二个参数用以指定读入的字节数，你可以通过它来限制从客户端获取数据的大小
// 下面这不就不解释了，不知道的自己面壁去
$input=trim($input);
//处理客户端输入并返回结果，当客户端发来数据信息后，信息输出就要靠socket_write()函数来完成
$output=strrev($input) ."\n";//反转字符串，这里仅仅是为了更好的区分两条信息
socket_write($spawn,$output,strlen($output)) or die("Could not write output\n");
// 关闭sockets
socket_close($spawn);
socket_close($socket);

Tip: You should use your command prompt to run the above code. The reason is because a server will be generated here, not a Web page. If you try to run this script using a web browser, there's a good chance it will exceed the 30-second limit. You can use the code below to set an infinite run time, but it is recommended to use the command prompt to run.

The code is as follows:

set_time_limit(0);

Simply test this script in your command prompt:

The code is as follows:

Php.exe socket_server.php

If you do not set the path of the php interpreter in the system environment variable, then you will need to specify the detailed path to php.exe. When you run the server, you can test the server by connecting to port 1337 via telnet.

There are three problems with the server side above:

1. It cannot accept multiple connections.

2. It only completes one command.

3. You cannot connect to this server through a web browser.

This first problem is easier to solve, you can use an application to connect to the server every time. But the next problem is that you need to use a Web page to connect to the server, which is more difficult. You can have your server accept the connection, write some data to the client (if it must write it), close the connection and wait for the next connection.

Improve on the previous code and generate the following code to make your new server:

<?php
$commonProtocol = getprotobyname("tcp");
$socket = socket_create(AF_INET, SOCK_STREAM, $commonProtocol);
socket_bind($socket, &#39;localhost&#39;, 1337); //socket_bind() 把socket绑定在一个IP地址和端口上
socket_listen($socket);
$buffer = "NO DATA";
while(true) {
 // Accept any connections coming in on this socket
 $connection = socket_accept($socket);//socket_accept() 接受一个Socket连接
 printf("Socket connected\r\n");
 // Check to see if there is anything in the buffer
 if($buffer != ""){
 printf("Something is in the buffer...sending data...\r\n");
 socket_write($connection, $buffer . "\r\n"); //socket_write() 写数据到socket缓存
 printf("Wrote to socket\r\n");
 }else {
 printf("No Data in the buffer\r\n");
 }
 // Get the input
 while($data = socket_read($connection, 1024, PHP_NORMAL_READ)){//socket_read() 读取指定长度的数据
 $buffer = $data;
 socket_write($connection, "Information Received\r\n");
 printf("Buffer: " . $buffer . "\r\n");
 }
 socket_close($connection); //socket_close() 关闭一个socket资源
 printf("Closed the socket\r\n\r\n");
}

What should this server do? It initializes a socket and opens a cache to send and receive data. It waits for a connection and once a connection is made it prints "Socket connected" on the screen on the server side. This server checks the buffer and if there is data in the buffer, it sends the data to the connected computer. It then sends an accept message for this data. Once it accepts the message, it saves the message to the data, makes the connected computer aware of the message, and finally closes the connection. When the connection is closed, the server starts processing the next connection.

Spawning a socket client

Handling the second problem is easy. You need to generate a php page, connect to a socket, send some data to its cache and process it. Then you have the processed data waiting, and you can send your data to the server. On another client connection, it will process that data.

The following example demonstrates the use of sockets:

<?php
// Create the socket and connect
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
$connection = socket_connect($socket,&#39;localhost&#39;, 1337);
while($buffer = socket_read($socket, 1024, PHP_NORMAL_READ)) {
 if($buffer == "NO DATA") {
 echo("<p>NO DATA</p>");
 break;
 }else{
 // Do something with the data in the buffer
 echo("<p>Buffer Data: " . $buffer . "</p>");
 }
}
echo("<p>Writing to Socket</p>");
// Write some test data to our socket
if(!socket_write($socket, "SOME DATA\r\n")){
 echo("<p>Write failed</p>");
}
// Read any response from the socket phpernote.com
while($buffer = socket_read($socket, 1024, PHP_NORMAL_READ)){
 echo("<p>Data sent was: SOME DATA<br> Response was:" . $buffer . "</p>");
}
echo("<p>Done Reading from Socket</p>");

The code in this example demonstrates the client connecting to the server. The client reads the data. If this is the first connection to arrive in this cycle, the server will send "NO DATA" back to the client. If this happens, the client is on top of the connection. The client sends its data to the server, the data is sent to the server, and the client waits for a response. Once the response is received, it writes the response to the screen.