Socket_read() says "not a valid resource" - php

Question

I am learning socket programming and experimenting using php.
I wanted to connect to a socket-server using a client and read the response of the server from the client.
Codes for :
Server.php:
$address="127.0.0.1";
$port=3343;
echo "I am here";
set_time_limit (0);
if(false==($socket= socket_create(AF_INET,SOCK_STREAM, SOL_TCP)))
{
echo "could not create socket";
}
socket_bind($socket, $address, $port) or die ("could not bind socket");
socket_listen($socket);
if(($client=socket_accept($socket)))
socket_write($client, "Welcome!!", 1024);
socket_close($socket);
Client.php
$host="127.0.0.1" ;
$port=3343;
$timeout=30;
$sk=fsockopen($host,$port,$errnum,$errstr,$timeout) ;
if (!is_resource($sk)) {
exit("connection fail: ".$errnum." ".$errstr) ;
} else {
echo socket_read($sk, 256);
//echo "Connected";
}
On connecting,
Server output :
I am here
Client Output :
Warning: socket_read(): supplied resource is not a valid Socket resource in C:\xampp\htdocs\users\srv\test\client.php on line 16

Answer 1

Found the problem here.
socket_read() doesn't work with sockets which have not been created with socket_create().
Working code :
$host="127.0.0.1" ;
$port=3343;
$timeout=30;
$sk=fsockopen($host,$port,$errnum,$errstr,$timeout) ;
if (!is_resource($sk)) {
exit("connection fail: ".$errnum." ".$errstr) ;
} else {
while (!feof($sk)) echo fgets($sk, 256); //This does the trick
//echo "Connected";
}

Answer 2

You are mixing the resource types.
fsockopen returns a file pointer. You need to use fread, fwrite etc. on it, and not socket_read.
socket_read accepts socket resources create with socket_create or socket_accept
Example for fsockopen from the PHP manual page:
<?php
$fp = fsockopen("udp://127.0.0.1", 13, $errno, $errstr);
if (!$fp) {
echo "ERROR: $errno - $errstr<br />\n";
} else {
fwrite($fp, "\n");
echo fread($fp, 26);
fclose($fp);
}
?>
fsockopen reference
socket_read reference