CAPTCHA Example

Usage

The following code will prepare a CAPTCHA image and keep the code in a session variable for later use:

After the call to simple_php_captcha() above, $_SESSION['captcha'] will be something like this:

Array ( [code] => yYY [image_src] => /mdrone/simple-php-captcha/simple-php-captcha.php?_CAPTCHA&t=0.11183400+1745955650 )
yYY

To display the CAPTCHA image, create an HTML <img> using $_SESSION['captcha']['image_src'] as the src attribute:

CAPTCHA code

To verify the CAPTCHA value on the next page load (or in an AJAX request), test against $_SESSION['captcha']['code']. You can use strtolower() or strtoupper() to perform a case-insensitive match.

Configuration

Configuration is easy and all values are optional. To specify one or more options, do this:

Notes

Important! Make sure you call session_start() before calling the simple_php_captcha() function
Requires PHP GD2 library
Backgound images must be in PNG format
Fonts must be either TTF or OTF
Backgrounds and fonts must be specified using their full paths (tip: use $_SERVER['DOCUMENT_ROOT'] . '/' . [path-to-file])
Angles should not exceed approximately 15 degrees, as the text will sometimes appear outside of the viewable area
Creates a function called simple_php_captcha() in the global namespace
Uses the $_SESSION['simple-php-captcha'] session variable