PHP implements the method of sending hexadecimal socket

<?php
        //~ $sendStr = &#39;7d 2c 00 00 00 00&#39;;  // 16进制数据
        $sendStr = "\x7D\x2c\x00\x00\x00\x00";  // 16进制数据
        
        //~ $sendStrArray = str_split(str_replace(&#39; &#39;, &#39;&#39;, $sendStr), 2);  // 将16进制数据转换成两个一组的数组


        $socket = socket_create(AF_INET, SOCK_STREAM, getprotobyname("tcp"));  // 创建Socket


        if (socket_connect($socket, "127.0.0.1", 50001)) {  //连接
socket_write($socket, $sendStr);  // 逐组数据发送
            //~ for ($j = 0; $j < count($sendStrArray); $j++) {
                //~ socket_write($socket, chr(hexdec($sendStrArray[$j])));  // 逐组数据发送
            //~ }


            $receiveStr = "";
            $receiveStr = socket_read($socket, 1024, PHP_BINARY_READ);  // 采用2进制方式接收数据
            $receiveStrHex = bin2hex($receiveStr);  // 将2进制数据转换成16进制


            echo "client:" . $receiveStrHex;
        }
        socket_close($socket);  // 关闭Socket
        ?>