สอบถามเรื่องการรับค่าจาก Socket TCP มาเขียนลงไฟล์ text บน Server ครับ

// set some variables
$host = "11.221.44.134";
$port = 9090;

// don’t timeout!
set_time_limit(0);

// create socket
$socket = socket_create(AF_INET, SOCK_STREAM, 0) or die("Could not create socket \n");

// bind socket to port
$result = socket_bind($socket, $host, $port) or die("Could not bind to socket \n");

// start listening for connections
$result = socket_listen($socket, 3) or die("Could not set up socket listener \n");

// accept incoming connections
// spawn another socket to handle communication
$spawn = socket_accept($socket) or die("Could not accept incoming connection \n");

// read client input
$input = socket_read($spawn, 1024) or die("Could not read input \n");

// clean up input string
$input = trim($input);

//Write data on text file --------
$fileName = "data.txt"; 
$fileopen = fopen($fileName, 'a+'); 
$write = $input."\r\n";
fwrite($fileopen, $write); 
fclose($fileopen);

// reverse client input and send back
$output = strrev($input) . "n";
socket_write($spawn, $output, strlen ($output)) or die("Could not write outputn");

// close sockets
socket_close($spawn);
socket_close($socket);