array preg_split(string pattern, string subject, int [limit], int [flags]);
Note: Parameter flags was added in PHP Beta 3.
Returns an array containing substrings of subject split along boundaries matched by pattern.
If limit is specified, then only substrings up to limit are returned.
If flags is PREG_SPLIT_NO_EMPTY then only non-empty pieces will be by preg_split().
Example 1. Getting parts of search string
$keywords = preg_split("/[\s,]+/", "hypertext language, programming");