I'm starting to learn ROR and have noticed that regular expressions show up quite often. I'd like to get a solid understanding of them, but no online tutorial seems to be sufficient.<p>I've seen that the books like <i>Mastering Regular Expressions</i> and <i>Regular Expressions Cookbook</i> have great reviews on Amazon, but I'm wondering if it would be overkill to get a full book on something that I would only be using every so often.<p>I've also considered getting a reference book on regex, but those seem to offer no introduction/explanations whatsoever (which I need).<p>Is it worth it for me to read up a lot on regex?
1. You mention RoR, so I assume you are not aiming to understand the abstract computer science notion, but the practical thing as to what regular expression libraries (ruby's in particular) understand.<p>2. You do not mention which online tutorials you found insufficient. That makes it hard to recommend things. For example do you know about <a href="http://www.regular-expressions.info" rel="nofollow">http://www.regular-expressions.info</a>?<p>3. Have you played with regular expressions interactively? That could be through the command line, or via <a href="http://rubular.com/" rel="nofollow">http://rubular.com/</a> (there are tons of such tools online, some better, but this one is for ruby)<p>As to your last question: whether it is worth for you? That depends on way too many unknowns for me to answer.
The best reference materials for regular expressions are available for free on all operating systems that have Perl installed: `perldoc perlretut` and `perldoc perlre`, in that order.<p>EDIT: ...in a terminal window.