Genetic Algorithm implementation.

See also "Weighted random selection" for RandomItemSelector class source.

This snippet illustrates using Genetic Algorithm for the hardware optimization.

This is a simple PHP script that will show whether a certain port/socket of a certain computer is currently open/active.

This multiple-use PHP script will randomly generate content based on a randomly generated number.

This simple function will check if a url is valid (going by parse_url()) and if it's 'online' - by seeing if it returns a 302, 301, or 200 status code.

This small snippet will not allow _POST requests from a 'foreign' domain. It relies on the HTTP_REFERER variable.

This function will reverse the affects of register_globals

The modus operandi for this is similar to that taken by PHP's implementation of such functions. It's comparitively memory-intensive, but is much faster than running a whole bunch of tests.

Basically, you set a mask -- an array of 256 null bytes -- and set those that correspond to characters you wish to trim. Then, rather than having to test if a character is in the set of characters to trim(O(n), or linear time on *ws), you just test once (O(1), or unit time) to see if the byte in question is set.

And of course, to trim(), you just wrap trim() around both ltrim() and rtrim().

One point of caution: these functions trim in place, so copy strings before trimming them. (Of course, if you usually want access to both pre- and post-trimmed strings, you could always make these malloc() a new string and return a pointer to it . . . )

Here's a little snippet I got from SitePoint that I now use all the time. Add the code below to the start of each script.

Basically, what this does is checks to see if magic_quotes_gpc() is enabled on the server, and if it is, then it gets rid of all the slashes that magic_quotes_gpc() adds to input from $_GET, $_POST and $_COOKIES globals.

It's a good snippet to use, because it negates the bad programming practices that having magic_quotes_gpc() lets you get away with, and means that you don't really on PHP to validate your input; you get to do it all yourself ;-)

A little function that does some basic checking for data input by a user. Should get rid of code injection ;-)