Linux.com: CAPTCHA Your Blog Comments with FOSS Utilities

"Bloggers hate automated comment spammers. One way to foil these vermin is a system called CAPTCHA, which is described in Wikipedia as 'an acronym for 'completely automated public Turing test to tell computers and humans apart''--in other words, a challenge-response system designed to determine whether a site visitor is human or a bot. Here's how I implemented a CAPTCHA system for blog comments using free and open source (FOSS) command-line utilities and PHP, the Web server scripting language.

"I've implemented this system under two Linux distributions--Ubuntu Dapper Drake and CentOS 4--both running the current versions of the Apache Web server and PHP. The CLI utilities are from GNU Enscript and ImageMagick..."

Complete Story

Related Stories:

• ONLamp: Do-It-Yourself Documentation? Research Into the Effectiveness of Mailing Lists (Part 1)(Aug 24, 2006)
• linux.GotFoo.org: Wired HowTo Guide Linux Style(Aug 05, 2006)
• Port 25: Honeypots and User-Mode-Linux (UML)(Jul 25, 2006)
• A Judge's World: Open Document Format(Jun 23, 2006)