class_cache.php is a class for caching arbitrary data about files in a given folder. It is intended to be used to reduce the time taken to serve dynamically generated pages. It works by checking if a cache file with a given key exists and is not older the cache expiration period. If it does not exist or has expired, the data is stored in a cache file. Otherwise, the data is retrieved from the cache file. MD5 sums are used to generate the names of the files on which the cached data is stored.
class_google.php is meant to connect to Google and perform a query. It lets you specify the query parameters as in the advanced search page of Google, and connects to Google via HTTP and retrieves the contents of the results page. It also parses the results to obtain the number of occurrences found for the specified query. The class requires PHP with TCP socket connection support enabled.
class_pictText is a PHP class that allows you to make a random string and print it in a picture to protect this string of robots. Output picture types are PNG or JPEG. You can specify a special TTF font file or let this class choose one in a specified folder. You can specify a folder for background pictures. The text to print can be specified or chosen randomly.
class_protect_picture is a PHP class which can be used to protect the path of your site's pictures in order to prevent somebody from using robot scripts to steal the images by accessing the pictures directly. The class changes the URL of the images used in HTML or tags, using a new URL through which real browsers can retrieve the picture files. The class requires PHP 4.0 or later with session support enabled.
class_sql_inject is a PHP class that searches your SQL data values for special characters that may change the meaning of your SQL data and execute actions that may compromise the security of servers. When some of these suspicious character sequences is found in HTTP POST request values ($_POST), you can either destroy the current session, redirect to a new page, or log the activity.