This has taken quite some time to track down. Ref this bug report over at bugs.php:

http://bugs.php.net/bug.php?id=42846

Personally from what I'm seeing, the comment in the report that this is just how PHP memory management works is incorrect. Calls to socket_read() in PHP 5.2.6 under Ubuntu 8.10 causes the process to grow without bounds.

Here is a slightly modified sample client and server pulled from the PHP documentation socket examples page::

The server code:

<?php
error_reporting(E_ALL);

/* Allow the script to hang around waiting for connections. */
set_time_limit(0);

/* Turn on implicit output flushing so we see what we're getting
 * as it comes in. */
ob_implicit_flush();

$address = '127.0.0.1';
$port = 10000;

if (($sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP)) === false) {
    echo "socket_create() failed: reason: " . socket_strerror(socket_last_error()) . "\n";
}

if (socket_bind($sock, $address, $port) === false) {
    echo "socket_bind() failed: reason: " . socket_strerror(socket_last_error($sock)) . "\n";
}

if (socket_listen($sock, 5) === false) {
    echo "socket_listen() failed: reason: " . socket_strerror(socket_last_error($sock)) . "\n";
}

do {
    if (($msgsock = socket_accept($sock)) === false) {
        echo "socket_accept() failed: reason: " . socket_strerror(socket_last_error($sock)) . "\n";
        break;
    }

    do {

	 	print( "MEMORY USAGE BEFORE READ IS '" . memory_get_usage() . "'\n" );

        if (false === ($buf = socket_read($msgsock, 2048, PHP_NORMAL_READ))) {
            echo "socket_read() failed: reason: " . socket_strerror(socket_last_error($msgsock)) . "\n";
            break 2;
        }

  	 	print( "MEMORY USAGE AFTER READ IS '" . memory_get_usage() . "'\n" );

    } while (true);

    socket_close($msgsock);

} while (true);

socket_close($sock);

?>

The client code:

<?php

error_reporting(E_ALL);

  echo "<h2>TCP/IP Connection</h2>\n";

  /* Get the port for the WWW service. */

$service_port = 10000;

  /* Get the IP address for the target host. */

$address = gethostbyname('localhost');

  /* Create a TCP/IP socket. */

$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);

if ($socket === false) {

    echo "socket_create() failed: reason: " . socket_strerror(socket_last_error()) . "\n";

} else {

    echo "OK.\n";

}

  echo "Attempting to connect to '$address' on port '$service_port'...";

$result = socket_connect($socket, $address, $service_port);

if ($result === false) {

    echo "socket_connect() failed.\nReason: ($result) " . socket_strerror(socket_last_error($socket)) . "\n";

} else {

    echo "OK.\n";

}

  while( true )

    {

      echo "Sending Hello";

      $in = "hello\n";

      socket_write($socket, $in, strlen($in));

    echo "OK.\n";

      sleep( 1 );

    }

  echo "Closing socket...";

socket_close($socket);

echo "OK.\n\n";

?>

Running it:

 Running it will produce a constantly growing server process.

 MEMORY USAGE BEFORE READ IS '61324'
MEMORY USAGE AFTER READ IS '61728'
MEMORY USAGE BEFORE READ IS '61788'
MEMORY USAGE AFTER READ IS '61924'
MEMORY USAGE BEFORE READ IS '61924'
MEMORY USAGE AFTER READ IS '61956'
MEMORY USAGE BEFORE READ IS '61956'
MEMORY USAGE AFTER READ IS '61988'
MEMORY USAGE BEFORE READ IS '61988'
MEMORY USAGE AFTER READ IS '62020'

If you don't want Verizon to start sharing various bits of your personal info with "affililiates, agents, or parent companies", you must notify them within 45 days. Further details can be had here.

Using a CSS styled unordered list you can create a fairly sophisticated navigational bar with rollover states.

In IE6 and IE7 without some special consideration, you end up with spurious white space rendered between the list item.

Click here for and HTML example of the problem (you'll need to be using IE 6 or IE 7).

Click here for an example of the fix and a detailed explanation of how to do it.

For ages I've been doing handstands dealing with the next and previous problem in SQL result sets. This is used, for instance, in the Member Photos section. 

Today I've been working to try to improve linking to the shared photos area. As of this writing, I still use the long encrypted links which embed values that make it easier for me to generate the next and previous link.

For ages, I've had this sense that there had to be an easier way.

And of course there is a MUCH better way than I've been doing it. Once I saw the solution, I found myself thinking "now why didn't I think that of that, it's so obvious".

So let's say you have a photo_id value which is the unique key of your list of photos. You want to know what the photo_id of the next and previous photos in the list is.

You can solve this problem with a very simple LEFT JOIN:

SELECT photos.photo_id, next.photo_id AS next_id, prev.photo_id AS prev_id
FROM photos
LEFT JOIN photos AS next ON next.photo_id > photos.photo_id
LEFT JOIN photos AS prev ON prev.photo_id < photos.photo_id
WHERE photos.photo_id = <photo_id to display here>
ORDER BY photos.photo_id ASC, prev_id DESC LIMIT 1