TCP Socket Server in PHP

This is a very basic TCP server written in PHP. Run it locally on your own machine; don’t try it on a production server first. It has an endless loop that will keep it going until you kill the process.

Thanks to John Schimmel for writing it.

#!/usr/local/bin/php –q 

<?php
// by John Schimmel
// modified from the code at http://www.zend.com/pecl/tutorials/sockets.php
//
// run this from terminal on mac os x or another command line interface.

// Set time limit to indefinite execution
set_time_limit (0); 

// Set the ip and port we will listen on
$address = '127.0.0.1';
$port = 9000; 

// Create a TCP Stream socket
$sock = socket_create(AF_INET, SOCK_STREAM, 0);
echo "PHP Socket Server started at " . $address . " " . $port . "\n";

// Bind the socket to an address/port
socket_bind($sock, $address, $port) or die('Could not bind to address');
// Start listening for connections
socket_listen($sock); 

//loop and listen

while (true) {
    /* Accept incoming requests and handle them as child processes */
    $client = socket_accept($sock); 

    // Read the input from the client – 1024 bytes
    $input = socket_read($client, 1024); 

    // Strip all white spaces from input
    $output = ereg_replace("[ \t\n\r]","",$input)."\0"; 

    // Display output back to client
    socket_write($client, "you wrote " . $input . "\n"); 

    // display input on server side
    echo "received: " . $input . "\n";
}

// Close the client (child) socket
socket_close($client); 

// Close the master sockets
socket_close($sock);
?>