I have already gone through some tutorials for socket but i couldn't get what it does. I want to know what sockets do and why is it used. This is the code I have referred.
client.php
<?php
$host = "localhost";
$port = 1024;
$message = "Hello Server";
echo "Message To server :".$message;
// create socket
$socket = socket_create(AF_INET, SOCK_STREAM, 0) or die("Could not create socket\n");
// connect to server
$result = socket_connect($socket, $host, $port) or die("Could not connect to server\n");
// send string to server
socket_write($socket, $message, strlen($message)) or die("Could not send data to server\n");
// get server response
$result = socket_read ($socket, 1024) or die("Could not read server response\n");
echo "Reply From Server :".$result;
// close socket
socket_close($socket);
?>
server.php
<?php
// set some variables
$host = "localhost";
$port = 1024;
// 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);
echo "Client Message : ".$input;
// reverse client input and send back
$output = strrev($input) . "\n";
socket_write($spawn, $output, strlen ($output)) or die("Could not write output\n");
// close sockets
socket_close($spawn);
socket_close($socket);
?>
So I couldn't get the idea of where to enter the server code and client code. Usually we write server code on what it should do while getting user input.So i am extremely confused about this. Can anyone help me? Thanks in advance
