PHP has many functions that help us to implement Internet and/or networking protocols. In this article we will look at how to implement some of those protocols using PHP.

His examples uses PHP's FTP methods to create a simple frontend to a remote FTP server. Included is the code to get the basics of it working - listing remote files and displaying them out in a styled list.

This is not strictly PHP, but it is about scalability, and every PHP programmer *ought* to be thinking about this stuff. Theo Schlossnagle of OmniTI (where I work as a web architect) has this slide deck posted about Scalable Internet Architectures.

Paul points out some highlights of the slides:

• Slide 7: "Lack of awareness of the other disciplines is bad."
• Slide 29: Know the difference between "premature optimization" and "necessary optimization".
• Slide 59: "Scaling is hard, performance is easier. Extremely high-performance systems tend to be easier to scale, because they don't have to SCALE as much."
• Slide 63: Combine this with slide 59, and you have the reason why you need to know your application responsiveness.

Of course you can debate how such a Top list came together and what the real value behind that is, but there are two specific points in this year's list that I found quite interesting.

There's two targets for the PHP community to worry about - sysadmin/hosting and things developers need to keep in mind. Items on these lists include:

• Always test and deploy patches and new versions of PHP as they are released
• Use Intrusion Prevention/Detection Systems to block/alert on malicious HTTP requests. Consider using Apache's mod_security to block known PHP attacks
• If you use PHP, migrate your application to PHP 5.2 as a matter of urgency.
• Encode all output using htmlentities() or a similar mechanism to avoid XSS attacks

I'm happy to announce that Adobe will be sponsoring the Zend / PHP Conference and Expo in San Jose in late October. I have a speaking session there on Rich Internet Applications, and we'll have a booth where we'll be showing off integrating PHP, using open source tools such as AMFPHP or WebORB from the Midnight Coders.

He also reminds potential conference-goers that the Early Bird discount is still in effect (until September 15th - just two more days!) to get the dicsounted price. Head over and register today!

I had the pleasure of meeting Theo Schlossnagle at OSCON 2006. He gave me 30 minutes to peek inside his brain and do an interview. 30 minutes just was not enough time. So when I received his latest book in the mail I was excited. Finally a chance to get more in-depth on some of the topics we covered. I've taken the time to collect my thoughts for you here so you can decide whether this book is a good one for you.

Cal talks about how he hated the book (from a reviewer's perspective, not a developer), the contents of the book, and his personal favorite section - "Distributed Databases are Easy, Just Read the Fine Print". His only critism is that the book seems to come across in a "demanding" tone (misunderstood by those that don't know Theo's style as just being matter of fact).

They start with links to the downloads for AMFPHP, and mention to "just follow the instructions" to get it set up. They provide a "create database" string to feed into MySQL before getting into the actual code for the application. The functionality grabs the list of users from the database table and stores it where the Flex interface can get to it.

The next step - generating the interface - is a simple one. They provide the code to cut and paste in to display all of the information the previous script had pulled out (in a datagrid).

Finally, they pull it all together, using the AMFPHP library to bridge the gap between the PHP script and the Flex interface, pushing the data into the Flex application.

Theo has been working on a book for Sams, "Scalable Internet Architectures", covering the proper ways to ensure that your site and systems will be up to handling whatever load (and kinds of load) is thrown their way. It looks at the traditional ways of handling issues that come up as well as some new tricks for those on a smaller budget.

The book hasn't been released yet (July 2006), but you can preorder it now from your favorite retailer online.

I thought 'Que?!', as I have not modified the code in class.atkoutput.inc in weeks, and certainly not tonight.

This code worked in all browsers, for years, without notices, because the HTTP_ACCEPT_ENCODING header is usually set for most major browsers.

He made a connection as to a probable cause - the error showed up when he had installed the Norton Internet Security software on his laptop. The firewall in this software was grabbing the header in the notice (the index for HTTP_ACCEPT_ENCODING in $_SERVER) and stripping it from the connection.

The (undocumented?) side effect is that with Norton Internet Security active, no page will be send gzipped. This is a performance penalty I think. They probably do it to be able to scan the text before it arrives in the browser (unzipping, scanning and rezipping would probably take too much time). ]]> Wed, 05 Apr 2006 07:00:13 -0500 http://www.phpdeveloper.org/news/5001 http://www.phpdeveloper.org/news/5001 new tutorial posted with complete details on creating a CAPTCHA image for your site (in the context of a blog).

This is a tutorial on how to make your own (very simple) CAPTCHA protection using PHP to create a dynamically generated jpeg image. This is useful for preventing comment spam. I have a working demo available, and I also use this technique to protect my scratchpad and weblog comments. You can download a zip file with all the files used in this tutorial.

They introduce what a CAPTCHA image is and some of its common uses around the internet, including it's high popularity on blogging software. Their example script creates an image with a random five-character hex phrase, centered, and puts longer lines through it to make it harder to read. They provide not only the script to make the actual image, but also explain how to use it in an HTML form to make it userful.

If you like the tutorial, be sure to digg it to share it with others.]]> Thu, 16 Mar 2006 07:17:27 -0600