Mailing the story:

Here's another topic that relates to our larger series on number pools and guaranteed combinations within fixed lists while still being worthy of having its own post. Regular expression matching with Perl for Linux or Unix is fairly simple at its most basic (as are most implementations of regular expression matching). Taken to its most remedial level, you can use a regular expression as a poor man's "grep" (and, oddly enough, the "re" in grep actually stands for regular expression). Although this use of regular expression pattern matching does have its place, it doesn't really merit use outside of tools designed to apply it in that manner and will suck all the joy right out of creating your own regular expressions.